Work vehicles

Abstract

In a configuration that includes a transmission located on the running body, the present invention provides a work vehicle that can protect the components around the transmission from foreign objects. [Solution] The combine harvester comprises a traveling body having left and right crawler sections 5, an engine mounted on the traveling body as a drive unit, a transmission 53 positioned on the traveling body and transmitting driving force to the left and right crawler sections 5, a drive belt 323 for transmitting engine power to the transmission 53, and a cover unit 400 that covers the drive belt 323 from at least one side.

Description

Technical Field

[0001] The present invention relates to a work vehicle equipped with a transmission disposed at the front portion or the like of a traveling body.

Background Art

[0002] Conventionally, in work vehicles such as combines, there are configurations equipped with a transmission disposed at the front portion or the like of a traveling body. In such a configuration, for example, Patent Document 1 discloses the following configuration as a power transmission configuration from an engine mounted on a traveling body to a transmission. That is, it is a configuration in which a drive belt is wound around an output pulley provided on an output shaft of an engine and an input pulley provided on an input shaft of a transmission (transmission case) disposed in front of the engine.

[0003] Further, for example, Patent Document 2 discloses a configuration in which a straight traveling vehicle speed sensor and a turning vehicle speed sensor for detecting respective outputs of a straight traveling output and a turning output related to a speed change output transmitted to a traveling portion are provided on a side surface portion of a transmission case, and a guard plate for protecting these sensors from mud and the like is provided.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The transmission is disposed at a relatively low position in the machine body, and the transmission and the drive belt wound around the input pulley of the transmission are present at a position relatively close to the ground during the work by the work vehicle.

[0006] For this reason, in harvesting operations using a combine harvester, for example, foreign objects such as the crop being harvested (harvested produce) or residual stalks may come into contact with the transmission or drive belt, causing problems with the machine's movement or malfunctions in the equipment configuration around the transmission. These problems are particularly likely to occur when harvesting corn, which has thicker stalks than rice or wheat.

[0007] This invention has been made in view of the above-mentioned problems, and aims to provide a work vehicle equipped with a transmission located on a running body that can protect the components around the transmission from foreign objects. [Means for solving the problem]

[0008] The work vehicle according to the present invention comprises a traveling body having left and right traveling devices, a drive source mounted on the traveling body, a transmission disposed on the traveling body and transmitting driving force to the left and right traveling devices, a drive belt for transmitting power from the drive source to the transmission, and a traveling drive system protection unit that covers at least one of the transmission and the drive belt from at least one side.

[0009] Another embodiment of the work vehicle according to the present invention is that the work vehicle has a protective cover that covers the drive belt from at least one side.

[0010] Another embodiment of the work vehicle according to the present invention is one in which the protective cover is configured to have an open side above the drive belt.

[0011] Another embodiment of the work vehicle according to the present invention is that the work vehicle has a lower guard provided below the drive belt that guards the drive belt from below.

[0012] Another embodiment of the work vehicle according to the present invention is such that the protective cover and the lower guard are integrally configured with respect to each other.

[0013] Another embodiment of the work vehicle according to the present invention is one in which the lower guard is provided in an inclined manner in the left-right direction of the machine body.

[0014] Another embodiment of the work vehicle according to the present invention is that, in the work vehicle, the drive belt is wound around a pulley whose axis is oriented in the left-right direction of the machine body, and the protective cover has a side cover portion that covers the drive belt from one side on the left or right, and a front cover portion that covers the drive belt from the front.

[0015] Another embodiment of the work vehicle according to the present invention is such that the lower guard is provided in an extensional manner in the longitudinal direction of the machine body, with its front end supported by the transmission and its rear end supported by the chassis of the running machine body.

[0016] Another embodiment of the work vehicle according to the present invention is the work vehicle wherein the lower guard has an opening or gap for discharging foreign matter.

[0017] Another embodiment of the work vehicle according to the present invention is that, in the work vehicle, the transmission is located at the front of the running body, and the running drive system protection unit has a protective cover provided on the front side of the transmission.

[0018] Another embodiment of the work vehicle according to the present invention is that the protective cover of the work vehicle comprises a front cover portion that covers the transmission from the front and a side cover portion that covers the transmission from at least one of the left and right sides.

[0019] Another aspect of the work vehicle according to the present invention is that in the work vehicle, the protective cover is configured such that the lower side is the open side.

[0020] Another aspect of the work vehicle according to the present invention is that in the work vehicle, the protective cover has a front cover portion that covers the transmission from the front, and the front cover portion is provided in a state of being inclined forward in a side view of the machine body.

[0021] Another aspect of the work vehicle according to the present invention is that in the work vehicle, the protective cover has a front cover portion that covers the transmission from the front, and the front cover portion has a through-opening.

[0022] Another aspect of the work vehicle according to the present invention is that in the work vehicle, the through-opening is a mesh portion.

[0023] Another aspect of the work vehicle according to the present invention is that in the work vehicle, the protective cover is attached to the transmission in a state of being fixed to the side surface portion of the transmission case of the transmission.

[0024] Another aspect of the work vehicle according to the present invention is that in the work vehicle, an operation member for operating on the transmission mechanism of the transmission is provided on the front side of the transmission, and the protective cover is provided so as to cover the operation member from the front.

[0025] Another aspect of the work vehicle according to the present invention is that in the work vehicle, a mowing unit is provided so as to be able to move up and down with respect to the traveling body, and the mowing unit includes a platform including a scraping auger rotatably provided with the left-right direction of the machine body as the rotation axis direction, and a mowing and conveying device including a pair of left and right conveyors attached to the front of the platform for sandwiching and conveying cereal straws and a cutting device for cutting cereal straws, and is configured as a corn header for mowing corn.

[0026] Another aspect of the work vehicle according to the present invention is that in the work vehicle, the traveling drive system protection unit includes a first cover unit that covers the drive belt from the side of one side of the left and right, a second cover unit that covers the transmission from the front, and a third cover unit provided between the first cover unit and the second cover unit.

Effects of the Invention

[0027] According to the present invention, in a configuration including a transmission disposed on a traveling body, the configuration around the transmission can be protected from foreign matters.

Brief Description of the Drawings

[0028] [Figure 1] It is a left side view of a combine according to a first embodiment of the present invention. [Figure 2] It is a right side view of a combine according to a first embodiment of the present invention. [Figure 3] It is a plan view of a combine according to a first embodiment of the present invention. [Figure 4] It is a diagram showing a power transmission configuration in a combine according to a first embodiment of the present invention. [Figure 5] It is a plan view showing a configuration of a grain and straw conveying device according to a first embodiment of the present invention. [Figure 6] It is a front perspective view showing a configuration of a cutting device according to a first embodiment of the present invention. <s [Figure 7] It is a diagram showing a configuration of a traveling drive system according to a first embodiment of the present invention. [Figure 8] It is a left front perspective view showing a configuration of a transmission and its periphery according to a first embodiment of the present invention. [Figure 9] It is a front view showing a configuration of a transmission and its periphery according to a first embodiment of the present invention. [Figure 10] It is a left front perspective view showing a configuration of a cover unit according to a first embodiment of the present invention. <00s00125> [Figure 11]This is a left side view showing the configuration of a cover unit according to the first embodiment of the present invention. [Figure 12] This is a plan view showing the configuration of a cover unit according to the first embodiment of the present invention. [Figure 13] This is a perspective view showing a protective cover according to the first embodiment of the present invention. [Figure 14] This is a perspective view showing the lower guard according to the first embodiment of the present invention. [Figure 15] This is a perspective view showing a support bracket according to the first embodiment of the present invention. [Figure 16] This is a front cross-sectional view showing the configuration of a modified example 1 of the cover unit according to the first embodiment of the present invention. [Figure 17] This is a perspective view showing the lower guard in a modified example 2 of the cover unit according to the first embodiment of the present invention. [Figure 18] This is a front cross-sectional view showing the configuration of a modified example 3 of the cover unit according to the first embodiment of the present invention. [Figure 19] This is a plan view showing the lower guard in a modified example 3 of the cover unit according to the first embodiment of the present invention. [Figure 20] This is a left front perspective view showing the configuration of the transmission and its surrounding area according to a second embodiment of the present invention. [Figure 21] This is a front view showing the configuration of a transmission and its surrounding area according to a second embodiment of the present invention. [Figure 22] This is a front view showing the configuration of the vicinity of the protective cover according to the second embodiment of the present invention. [Figure 23] This is a left side view showing the configuration of the vicinity of the protective cover according to the second embodiment of the present invention. [Figure 24] This is a front perspective view showing a protective cover according to a second embodiment of the present invention. [Figure 25] This is a plan view showing a protective cover according to a second embodiment of the present invention. [Figure 26] This is a rear view showing a protective cover according to a second embodiment of the present invention. [Figure 27]This is a front perspective view showing the right cover member according to a second embodiment of the present invention. [Figure 28] This is a front perspective view showing the left cover member according to a second embodiment of the present invention. [Figure 29] This is a front perspective view showing the support arm portion according to a second embodiment of the present invention. [Figure 30] This is an exploded perspective view showing the support configuration of a protective cover according to a second embodiment of the present invention. [Figure 31] This is a front perspective view showing the attachment portion of the protective cover to the transmission case according to the second embodiment of the present invention. [Figure 32] This is a left front perspective view showing the configuration of the transmission and its surrounding area according to a third embodiment of the present invention. [Figure 33] This is a front view showing the configuration of the transmission and its surrounding area according to a third embodiment of the present invention. [Figure 34] This is a left side view showing the configuration of the mounting portion and surrounding area of ​​the protective cover according to the third embodiment of the present invention. [Figure 35] This is a right side view showing the configuration of the mounting portion and surrounding area of ​​the protective cover according to the third embodiment of the present invention. [Figure 36] This is a front view showing the vicinity of the protective cover according to the third embodiment of the present invention. [Figure 37] This is a left front perspective view showing the configuration of the cover member according to the third embodiment of the present invention. [Figure 38] This is a rear perspective view showing a protective cover according to a third embodiment of the present invention. [Figure 39] This is a rear view showing a protective cover according to a third embodiment of the present invention. [Figure 40] This is a left side view showing a protective cover according to a third embodiment of the present invention. [Figure 41] This is a right side view showing a protective cover according to a third embodiment of the present invention. [Figure 42] This is an exploded perspective view showing the configuration of a protective cover according to a third embodiment of the present invention. [Figure 43]This figure shows a modified configuration of the cover body according to the third embodiment of the present invention. [Figure 44] This is a left front perspective view showing the configuration of the transmission and its surrounding area according to a fourth embodiment of the present invention. [Figure 45] This is a front view showing the configuration of a transmission and its surrounding area according to a fourth embodiment of the present invention. [Figure 46] This is a left side view showing the configuration of a cover unit according to a fourth embodiment of the present invention. [Figure 47] This is a left front perspective view showing the configuration of a cover unit according to a fourth embodiment of the present invention. [Figure 48] This is a plan view showing the configuration of a cover unit and its support configuration according to a fourth embodiment of the present invention. [Figure 49] This is a front view showing the configuration of a cover unit according to a fourth embodiment of the present invention. [Figure 50] This is a plan cross-sectional view showing the mounting structure of a cover unit according to the fourth embodiment of the present invention. [Figure 51] This is an upper right cross-sectional perspective view showing the mounting structure of the cover unit according to the fourth embodiment of the present invention. [Modes for carrying out the invention]

[0029] The present invention aims to protect the components around the transmission from foreign objects such as crops to be harvested, by providing a drive system protection unit that covers the transmission from at least one side, in a configuration in which a transmission is arranged on a traveling machine. Embodiments of the present invention will be described below. In the embodiments of the present invention described below, a conventional combine harvester will be used as an example of the work vehicle according to the present invention. However, the work vehicle according to the present invention may be other types of combine harvesters such as self-propelled combine harvesters, or it may be a work vehicle other than a combine harvester.

[0030] [First Embodiment] A first embodiment of the present invention will now be described. In this embodiment, the combine harvester is provided with a protective cover that constitutes a drive system protection unit for the drive belt that transmits power from the drive source to the transmission, thereby suppressing the occurrence of malfunctions such as the drive belt coming off or being damaged.

[0031] The overall configuration of the combine harvester 1 according to the first embodiment of the present invention will be described using Figures 1 to 6. In the following description, the left side (lower side in Figure 3) and the right side (upper side in Figure 3) of the combine harvester 1, when viewed from the front, will be referred to as the left and right sides of the combine harvester 1, respectively.

[0032] As shown in Figures 1 and 2, the combine harvester 1 according to this embodiment is a conventional combine harvester that collects harvested field crops (rice, wheat, soybeans, corn, etc.) into the machine body, threshes, sorts, stores the grain, and allows for appropriate transport outside the machine. The combine harvester 1 has a self-propelled traveling body 2 and a harvesting unit 3 provided at the front end of the traveling body 2. The harvesting unit 3 is configured as a harvesting device that cuts and collects unharvested grain stalks of crops, and is mounted on the traveling body 2 so as to be able to move up and down.

[0033] The running machine body 2 is equipped with a crawler-type running machine 4 having a pair of crawler sections 5, 5 as left and right running devices. A machine frame 6 is installed between the left and right crawler sections 5, 5. Each crawler section 5 has a drive sprocket 5a and a plurality of rolling wheels 5b provided at its front end, and a track 5c wound around these rotating bodies. The drive sprocket 5a is rotationally driven by power transmitted from the engine 25 of the combine harvester 1.

[0034] On the left side of the machine frame 6, there is a threshing unit 7 for threshing the stalks of grain that have been cut and supplied by the harvesting unit 3, and a sorting unit 8 for sorting the grains threshed by the threshing unit 7. The threshing unit 7 and the sorting unit 8 are arranged behind the harvesting unit 3, with the threshing unit 7 on the upper level and the sorting unit 8 on the lower level.

[0035] On the machine frame 6, a grain storage section 9 is provided to the right of the threshing section 7 and sorting section 8, and has a grain tank 10 for storing the grain sorted in the sorting section 8. Inside the grain tank 10, a lower discharge conveyor 11 is provided to transport the stored grain toward the discharge port of the grain tank 10 (see Figure 4). A vertical conveyor 12 is erected vertically so as to communicate with the discharge port of the grain tank 10. A grain discharge conveyor 13 is connected to the upper end of the vertical conveyor 12. The grain discharge conveyor 13 is provided so as to be able to rotate horizontally and swing up and down around a horizontal axis. The grain in the grain tank 10 is transported by these conveyors and discharged from a paddy input port 14 provided at the tip of the grain discharge conveyor 13 to the bed of a truck or a container.

[0036] On the machine frame 6, the driver's compartment 15 is located in front of the grain storage section 9, that is, in the front right position on the machine frame 6, where the operator sits. The driver's compartment 15 is covered by a cabin 16. The driver's compartment 15 is equipped with a driver's seat 17, a steering wheel 18 located in front of the driver's seat 17, and various operating parts such as a main gear lever 19, a sub-gear lever, and a work clutch lever (see Figure 2). The work clutch lever is an operating tool for engaging and disengaging the threshing clutch 57 and the harvesting clutch 75 (see Figure 4).

[0037] Below the control unit 15 on the aircraft frame 6, an engine 25 is provided as the power source. The engine 25 is located in the space below the control unit 15, on the front right side of the aircraft frame 6. The engine 25 is, for example, a diesel engine.

[0038] The harvesting unit 3 will now be described. The harvesting unit 3 includes a feeder 30 as a supply and conveying device, a platform 31 as a grain header, and a harvesting and conveying device 32 that harvests and conveys crops.

[0039] The harvesting unit 3 is configured as a so-called low-crop header, with a harvesting and conveying device 32 attached to the front of the platform 31. In particular, the harvesting unit 3 according to this embodiment is configured as a corn header mainly used for harvesting corn. In the combine harvester 1, instead of a low-crop header, a configuration including a platform, cutting blade device, grass divider, raking reel, etc., can be attached to the feeder 30.

[0040] The feeder 30 transports the stalks harvested in the harvesting section 3 and supplies them to the threshing section 7. The feeder 30 has a feeder house 35 as a housing and a conveyor 36 (see Figure 4) for transporting stalks provided inside the feeder house 35. The feeder 30 is located to the left of the cabin 16 and is provided with the rear end opening of the feeder house 35, which is configured as a roughly rectangular tube with its longitudinal direction as the front-to-back direction in a plan view, communicating with the front opening 7a on the front side of the threshing section 7.

[0041] The conveyor 36 is a chain conveyor having chains 95 arranged parallel to each other on both the left and right sides within the feeder house 35, and a plurality of slats 96 installed between the left and right chains 95 (see Figure 4). The conveyor 36 has a harvesting unit input shaft (feeder house conveyor shaft) 38, which is located at the front of the threshing unit 7 and has its axis oriented in the left-right direction, as a drive shaft that pivots at the end of the conveyor 36. The rear portion of the chain 95 is wound around a sprocket 97 fixed to the harvesting unit input shaft 38. On the other hand, the front portion of the chain 95 is wound around a cylindrical front drum 98, which is located at the front end of the feeder house 35 and is pivotally supported so as to be rotatable with its axis oriented in the left-right direction.

[0042] The rear end of the feeder 30 is rotatably supported relative to the traveling machine 2, with the harvesting unit input shaft 38 as the pivot axis. A hydraulic cylinder, which is a lifting cylinder, is interposed between the lower surface of the feeder house 35 and the machine frame 6. The rotation of the feeder 30 relative to the traveling machine 2 due to the extension and retraction of the lifting cylinder causes the harvesting unit 3 to move up and down. The height of the harvesting unit 3 is adjusted by the lifting and lowering movement of the harvesting unit 3.

[0043] The platform 31 is configured in a horizontal bucket shape and is connected to the front side of the feeder 30 so as to communicate with the front end opening of the feeder house 35. The platform 31 has a harvesting section frame 210 which is composed of a left side wall 201 and a right side wall 202, a rear wall 203 and a bottom surface 204, forming a space with the front and top open as a space for inputting grain stalks. A rectangular intake opening 205 is formed in the rear wall 203, facing the front end opening of the feeder house 35 (see Figure 3). The feeder house 35 is located to the left of the center in the left-right direction relative to the platform 31, and the intake opening 205 opens into the platform 31 at a position to the left of the left-right center.

[0044] A scraping auger (platform auger) 37 is provided inside the platform 31. The scraping auger 37 is rotatably mounted between the left wall portion 201 and the right wall portion 202 of the platform 31, with the left-right direction as the axis of rotation.

[0045] The harvesting and conveying device 32 comprises multiple configurations of combinations of grain stalk conveying devices 33 and cutting devices 34. In this embodiment, the harvesting and conveying device 32 has three sets of grain stalk conveying devices 33 and cutting devices 34 arranged in parallel on the left and right sides, corresponding to three continuous rows in the left-right direction, and constitutes a three-row harvesting unit 3.

[0046] The grain stalk conveying device 33 is equipped with a pair of chain conveyors 220 on the left and right sides, and is configured to convey grain stalks by positioning them between the left and right chain conveyors 220. The space between the left and right chain conveyors 220 serves as the conveying passage for the grain stalks. Each chain conveyor 220 extends forward from the harvesting frame 210 and has a configuration in which an endless rotating conveying chain 222 is arranged so that the front-to-back direction is the longitudinal direction in a plan view.

[0047] The chain conveyor 220 is covered from above by a conveyor cover 221. The grain stalk conveying device 33 has a configuration that includes three pairs of left and right chain conveyors 220 arranged side by side, and the conveyor cover 221 includes an outer conveyor cover 221a that covers the chain conveyors 220 located at the left and right outer ends, and two inner conveyor covers 221b that cover two adjacent chain conveyors 220 in the left and right middle sections. A grass divider 230 is provided on the front side of each conveyor cover 221. The grass divider 230 has a pointed covering form that is integrated with the conveyor cover 221 on the front side of the conveyor cover 221.

[0048] The conveying chain 222 is wrapped around a drive sprocket 223, which is a drive wheel located on the rear side (the downstream side of the conveying mechanism), and a driven sprocket 224, which is a driven wheel located on the front side (the upstream side of the conveying mechanism). In the conveying chain 222, a plurality of tines 222a are provided so as to protrude outward at predetermined intervals in the circumferential direction.

[0049] A pair of conveying chains 222 grip the grain stalks with tines 222a on opposite sides, and rotate in a direction that moves the opposing sides toward the direction of conveying the grain stalks by the rotational drive of the drive sprocket 223 (see Figure 5, arrow A1). The drive sprocket 223 is rotationally driven by power transmitted from the engine 25 via a predetermined transmission mechanism.

[0050] The cutting device 34 is located below the grain stalk conveying device 33. As shown in Figure 6, the cutting device 34 has a pair of left and right rotating blades 225. The pair of left and right rotating blades 225 extend forward from drive cases 226 provided for each set of grain stalk conveying device 33 and cutting device 34 within the harvesting frame 210. The pair of left and right rotating blades 225 are arranged parallel to a pair of left and right chain conveying bodies 220. The pair of left and right rotating blades 225 are arranged adjacent to each other with a gap in the left-right direction, and the gap between the pair of rotating blades 225 corresponds to the distance between the pair of chain conveying bodies 220 in the left-right direction.

[0051] As shown in Figure 6, the rotating blade section 225 has a substantially cylindrical rotating body 227 and a plurality of cutter bodies 228 that serve as rotating blades. The rotating body 227 extends forward from the drive case 226. The cutter bodies 228 are longitudinal members aligned along the longitudinal direction of the rotating body 227, and are arranged in multiple locations (for example, four locations) in the circumferential direction on the outer surface of the rotating body 227, and are attached to the rotating body 227 in a fixed state by bolts or the like.

[0052] The drive case 226 is configured as a box shape with its longitudinal direction running horizontally. Inside the drive case 226, there is a transmission mechanism for transmitting power from the engine 25 to the grain stalk conveying device 33 and the cutting device 34. This transmission mechanism is composed of bevel gears and the like. The transmission mechanisms in adjacent drive cases 226 are linked together by relay shafts 229 with their axial direction running horizontally. Of the three drive cases 226 arranged side by side horizontally, the transmission mechanism of the drive case 226 located on the right is linked together with an input shaft that is coaxially positioned with the relay shaft 229 and extends to the right from the right drive case 226. The rotational power transmitted from the engine 25 is input to the right drive case 226 by the input shaft, and this rotational power is transmitted to the transmission mechanisms in the central and left drive cases 226 by each relay shaft 229.

[0053] From both the left and right sides of the upper surface of the drive case 226, transport drive shafts 80 that drive the grain stalk transport device 33 extend upward. Each transport drive shaft 80 is pivotally supported by drive sprockets 223 for the left and right chain transport bodies 220. As the transport drive shafts 80 rotate, the drive sprockets 223 rotate, driving the chain transport bodies 220.

[0054] Furthermore, the power transmitted by the transmission mechanism within the drive case 226 drives the left and right pair of rotating bodies 227 of the cutting device 34 to rotate around a predetermined axis of rotation that coincides with the central axis of the substantially cylindrical rotating body 227. The left and right pair of rotating bodies 227 rotate in opposite directions, moving their opposing sides (left and right inner sides) downwards (see Figure 6, arrow A2).

[0055] As described above, the harvesting unit 3, which is provided to be able to move up and down relative to the traveling machine body 2, has a platform 31 including a scraping auger 37 that is provided to be able to move with the left-right direction of the machine body as the axis of rotation, and a harvesting conveying device 32 that is attached to the front of the platform 31 and includes a grain stalk conveying device 33 including a pair of left and right chain conveying bodies 220 for gripping and conveying grain stalks, and a cutting device 34 for cutting grain stalks, and is configured as a corn header for harvesting corn.

[0056] A front rotor 26 is provided at the rear of the feeder 30 to feed the stalks of grain being transported by the conveyor 36 to the threshing opening 7a. The front rotor 26 is located between the end of the conveyor 36 and the threshing opening 7a. The front rotor 26 has a roughly cylindrical rotor body, also called a beater, and a front rotor shaft 28 (see Figure 4) whose axis is oriented in the left-right direction. The stalks of grain transported by the feeder 30 are fed from the end of the conveyor 36 through the threshing opening 7a into the threshing chamber 7b of the threshing unit 7 by the front rotor 26.

[0057] The threshing section 7 and the sorting section 8 will now be described. The threshing section 7 has a threshing drum 40 located in a threshing chamber 7b with a threshing opening 7a facing forward, and a receiving net 42 positioned below the threshing drum 40. The threshing chamber 7b is formed by a machine frame provided on the machine frame 6.

[0058] The threshing drum 40 is rotatably supported by a threshing drum shaft 41 (see Figure 4) whose axis is oriented in the front-rear direction. The threshing drum 40 has a cylindrical body portion aligned with the threshing drum shaft 41 as its central axis, and rod-shaped threshing teeth are provided on the outer surface of the body portion. Multiple dust supply valves are provided on the upper side of the threshing drum 40, which are angle-adjustable for adjusting the conveying speed (residence time) of the threshed grain in the threshing chamber 7b. The receiving net 42 is for allowing the grain to leak out and is provided along the outer surface of the lower part of the threshing drum 40.

[0059] The sorting unit 8 includes an oscillating sorting plate 43, which is an oscillating sorting unit positioned below the threshing unit 7 via a receiving net 42; an oscillating mechanism 44 including an oscillating shaft 44a; a first conveyor 45; a second conveyor 46; and a winnowing machine 47. The oscillating mechanism 44 rotates the oscillating shaft 44a using rotational power from a drive source, causing the oscillating sorting plate 43 to reciprocate in a predetermined direction that is the front-rear direction in a plan view. A pre-fan 71 is provided in front of the winnowing machine 47, and a second fan 72 is provided behind the winnowing machine 47.

[0060] The oscillating sorting plate 43 has a feed pan, a chaff sieve positioned behind the feed pan to adjust the amount of grain leakage, and a grain sieve positioned below the chaff sieve, among other components for specific gravity sorting. The first conveyor 45 is positioned in the first trough, which extends in the machine width direction, to collect the first grain (first grade). The second conveyor 46 is positioned behind the first conveyor 45 and is positioned in the second trough, which extends in the machine width direction, to collect the second grade grain. The winnowing machine 47 blows sorting air onto the oscillating sorting plate 43, which exits from the front-downward to the rear-upward.

[0061] Furthermore, a return conveyor 48 is provided on the right side of the machine body where the threshing section 7 and sorting section 8 are located (see Figure 4). The return conveyor 48 is connected to the second conveyor 46 with its lower end positioned near the second conveyor 46, and its upper end is positioned near the front end of the threshing drum 40, extending in an upward sloping manner. To the right of the return conveyor 48, a vertically extending grain lifting conveyor 49 is provided. The grain lifting conveyor 49 transports the first grain, which has been sent by the first conveyor 45, into the grain tank 10.

[0062] The combine harvester 1, with the configuration described above, raises the harvesting unit 3 to a desired height (the harvesting height of the grain stalks) relative to the ground by the lifting and lowering motion of the feeder 30, which is centered (supported) on the harvesting unit input shaft 38, in the field, and moves from a non-working state to a working state, and then moves on the traveling machine body 2 in that state. As a result, the combine harvester 1 separates the harvested crop into those to be harvested and those not to be harvested by the grass divider 230, and cuts the grain stalks to be harvested by the cutting device 34 while taking in the grain stalks to be harvested by the grain stalk conveying device 33. The cutting device 34 cuts the corn stalks introduced into the gap between the left and right pair of rotating blades 225 with the left and right cutter bodies 228.

[0063] The corn stalks (corn bundles) whose stems have been cut by the cutting device 34 are transported to the rear by the feeding action of the tines 222a of the conveying chain 222 in the corn bundle conveying device 33, and are raked into the platform 31 from the rear end of the conveying device 33 by the rotationally driven raking auger 37. The corn bundles raked into the platform 31 are taken into the feeder house 35 by the feeding action of the raking auger 37, and are passed through the feeder house 35 by the conveyor 36 and fed into the threshing opening 7a by the front rotor 26, and supplied to the threshing unit 7.

[0064] The corn supplied to the threshing unit 7 undergoes a threshing process in which the corn seeds are separated. Specifically, the corn supplied to the threshing unit 7 is conveyed backward by a rotating threshing drum 40, and is threshed mainly between the threshing drum 40 and the receiving screen 42. Threshed grains smaller than the mesh size of the receiving screen 42 leak through the receiving screen 42. Bulbs and debris that have come off the corn husks and do not leak through the receiving screen 42 are discharged into the field through a dust outlet located at the rear of the sorting unit 8 by the conveying action of the threshing drum 40.

[0065] Meanwhile, the grains that have been threshed in the threshing section 7 and have leaked out of the receiving screen 42 are sorted in the sorting section 8. Specifically, the threshed grains that have been threshed in the threshing drum 40 and have leaked out of the receiving screen 42 are sorted into fine grains (first grade), a mixture of grains and waste (second grade), and waste, etc., by the specific gravity sorting action of the oscillating sorting plate 43 and the wind sorting action of the winnowing machine 47, and then removed.

[0066] The grains (first-grade) that fall from the oscillating sorting plate 43 after sorting in the sorting section 8 are transported to the grain tank 10 by the first conveyor 45 and the connected lifting grain conveyor 49. The second-grade grains are returned to the threshing start end of the threshing drum 40 by the second conveyor 46 and the connected return conveyor 48, where they undergo threshing again. Scraps and other debris are discharged into the field through a dust discharge port located at the rear of the sorting section 8.

[0067] Next, the power transmission configuration of the combine harvester 1 according to this embodiment will be explained with reference to Figure 4. The combine harvester 1 uses the rotational power of the engine 25 to drive the harvesting unit 3, the traveling unit 4, the threshing unit 7, the sorting unit 8, and the grain storage unit 9.

[0068] As shown in Figure 4, the engine 25 has a first output shaft 25a and a second output shaft 25b. The rotational power of the first output shaft 25a is transmitted to the traveling unit 4, the threshing unit 7, the sorting unit 8, and the harvesting unit 3. The rotational power of the second output shaft 25b is transmitted to the grain storage unit 9. The engine 25 also has a implement pump shaft that drives a charge pump 54 which operates the lifting cylinder and other components of the harvesting unit 3.

[0069] Regarding the power transmission system to the running section 4, the rotational power of the first output shaft 25a is transmitted by the first belt transmission mechanism 51 to the transmission input shaft 52, which is the HST input shaft, and input to the transmission 53, which includes the running HST 311 and the turning HST 312. Here, "HST" refers to a hydraulic continuously variable transmission that employs a method of converting hydraulic pressure generated by driving a hydraulic pump back into rotational force using a hydraulic motor. The driving force of the transmission 53 rotates the drive sprocket 5a of the crawler section 5 that constitutes the running section 4.

[0070] Regarding the power transmission system to the threshing unit 7, the rotational power of the first output shaft 25a is transmitted to the threshing unit input shaft 56 by the second belt transmission mechanism 55. The second belt transmission mechanism 55 is provided with a threshing clutch 57 that transmits the rotational power of the first output shaft 25a to the threshing unit input shaft 56 intermittently as needed.

[0071] The rotational power of the threshing unit input shaft 56 is transmitted to the threshing drum input shaft 59 by the third belt transmission mechanism 58. The rotational power of the threshing drum input shaft 59 is transmitted to the threshing drum shaft 41 via the threshing speed change device 60. The threshing speed change device 60 performs a two-stage speed change, for example, between high speed and low speed, on the rotational power input from the threshing drum input shaft 59 to the threshing drum shaft 41.

[0072] With this configuration, the driving force of the engine 25 is transmitted to the threshing unit 7. Then, by operating the work clutch lever provided on the driver's unit 15, the threshing clutch 57 is turned ON / OFF, thereby intermittently transmitting power to the threshing unit 7.

[0073] Regarding the power transmission system to the sorting section 8, the threshing section input shaft 56 has a support shaft for the winnowing machine 47, and the rotational power of the threshing section input shaft 56 is transmitted by the fourth belt transmission mechanism 61 to a pulley rotating body 63 supported on the threshing intermediate shaft 62. The rotational power of the pulley rotating body 63 is transmitted to the pre-fan 71 and the winnowing machine 47 by a predetermined transmission mechanism. In addition, the rotational power of the threshing section input shaft 56 is transmitted by a predetermined transmission mechanism to the rotating shafts of the first conveyor 45, the second fan 72, and the second conveyor 46, respectively.

[0074] The rotational power of the first conveyor 45 is transmitted to the grain lifting conveyor 49 by a predetermined transmission mechanism. The rotational power of the second conveyor 46 is transmitted to the oscillating shaft 44a of the oscillating mechanism 44 by the fifth belt transmission mechanism 64. The rotational power of the second conveyor 46 is transmitted to the return conveyor 48 via bevel gears.

[0075] Regarding the power transmission system to the grain storage section 9, the rotational power of the second output shaft 25b is transmitted to the lower discharge conveyor 11 by a power transmission mechanism including the grain tank intermediate shaft 77. The rotational power of the lower discharge conveyor 11 is transmitted to the vertical conveying conveyor 12 via bevel gears. The rotational power of the vertical conveying conveyor 12 is transmitted to the grain discharge conveyor 13 by a predetermined transmission mechanism. The grain storage section 9 is equipped with a suction fan 78 and a compressor 79, which are driven by the rotational power transmitted from the grain tank intermediate shaft 77.

[0076] Regarding the power transmission system to the harvesting unit 3, the rotational power of the pulley rotating body 63 is transmitted to the front rotor shaft 28 by the sixth belt transmission mechanism 73. The sixth belt transmission mechanism 73 is equipped with a harvesting clutch 75 that transmits the rotational power of the pulley rotating body 63 to the front rotor shaft 28 intermittently as needed. The rotational power of the front rotor shaft 28 is transmitted to the harvesting unit input shaft 38 by the first chain transmission mechanism 65. The rotational drive of the harvesting unit input shaft 38 operates the conveyor 36 inside the feeder house 35.

[0077] The rotational power of the harvesting unit input shaft 38 is transmitted by a predetermined transmission mechanism to the transmission mechanism within each drive case 226 via an input shaft extending to the right from the right-side drive case 226, as described above. This causes the left and right pair of chain conveyors 220 of each grain stalk conveying device 33 and the left and right pair of rotating blades 225 of each cutting device 34 to rotate.

[0078] With this configuration, the driving force of the engine 25 is transmitted to the harvesting unit 3. Then, by operating the work clutch lever provided on the driver's unit 15, the harvesting clutch 75 (see Figure 4) is turned ON / OFF, thereby intermittently transmitting power to the harvesting unit 3.

[0079] The arrangement of the transmission 53 and the surrounding configuration will be explained using Figures 7 to 9.

[0080] As shown in Figure 7, the transmission 53 is a drive device that drives the left and right crawler sections 5, and has a transmission body section 301 and an HST section 302 including a travel HST 311 and a turning HST 312. The transmission 53 is located to the left front of the engine 25.

[0081] As shown in Figures 8 and 9, the transmission 53 is positioned between the front ends of the left and right crawler sections 5, with its upper part protruding upward relative to the left and right crawler sections 5 in the vertical direction. The transmission 53 is fixedly supported by the chassis 305 that constitutes the running machine body 2, and its front side is supported by the left and right crawler sections 5 via drive sprockets 5a.

[0082] The chassis 305 is the base portion that forms the body frame 6 of the running machine 2, and is horizontally framed by frame members such as pipe-shaped members and plate-shaped members arranged in the front-rear direction or left-right direction. In the front-rear direction, the rear side of the chassis 305 extends backward from the rear end of the crawler section 5.

[0083] The transmission body 301 incorporates a power transmission mechanism, including a gear group and clutch, within the transmission case 303, and transmits power from the engine 25 to the left and right crawler sections 5 after appropriately shifting the gear ratio. The transmission body 301 has a sub-transmission mechanism 306 and a differential mechanism 307 as power transmission mechanisms housed in the transmission case 303 (see Figure 7).

[0084] The transmission case 303 has a left-right split structure in which the left and right case bodies are fastened and fixed together at multiple points with bolts. The transmission case 303 has protruding case portions 303a on both the left and right sides of the lower part, which protrude downward from the main case body, and cylindrical axle case portions 303b extend outward from each protruding case portion 303a to the left and right. An axle 308 is rotatably supported inside each axle case portion 303b. A drive sprocket 5a is attached to the portion of the axle 308 that protrudes from the axle case portion 303b.

[0085] The HST unit 302 is located on the upper side of the transmission body 301. The HST unit 302 has an HST case 313 into which a travel HST 311 and a turning HST 312 are assembled. The HST case 313 is mounted on the upper side of the transmission case 303.

[0086] The transmission 53 has a transmission input shaft 52 extending to the left (see Figure 7). The transmission input shaft 52 extends from the HST section 302. As described above, the transmission 53 receives power from the engine 25 via the first belt drive mechanism 51 (see Figure 4).

[0087] The first belt drive mechanism 51 includes an engine output pulley 321, which is a first pulley fixed to the protruding end (left end) of the first output shaft 25a that protrudes to the left in the engine 25; a transmission input pulley 322, which is a second pulley fixed to the protruding end (left end) of the transmission input shaft 52; and a drive belt 323, which is an endless engine output belt wound around these pulleys. Both the engine output pulley 321 and the transmission input pulley 322 have their rotation axis direction in the left-right direction of the machine.

[0088] The transmission input pulley 322 is a smaller diameter pulley than the engine output pulley 321. The transmission input pulley 322 is positioned in front of the engine output pulley 321, and the drive belt 323 is arranged in a front-to-back extension configuration. The engine output pulley 321 and the transmission input pulley 322 are a so-called triple pulley system, having three adjacent outer circumference grooves in the direction of rotation. The drive belt 323 is composed of three belt elements that engage with each outer circumference groove of both pulleys.

[0089] The first belt drive mechanism 51 has a tension pulley 324 that acts on the drive belt 323. The tension pulley 324 has its rotation axis oriented in the left-right direction of the machine body and is provided to press against the portion of the drive belt 323 that is installed between the engine output pulley 321 and the transmission input pulley 322 from above (outer circumference).

[0090] The tension pulley 324 is positioned between the engine output pulley 321 and the transmission input pulley 322, slightly forward of the front-to-back center. Due to the tension pulley 324, the path portion of the drive belt 323 between the upper ends of the engine output pulley 321 and the transmission input pulley 322 has a flattened, roughly V-shaped bend. The tension pulley 324 is smaller in diameter than the transmission input pulley 322. The tension pulley 324 is supported by a support device 325, which includes a biasing member (not shown) such as a spring that generates a pressing biasing force on the drive belt 323, so that it can rotate in the left-to-right direction with the rotation axis as the axis of rotation.

[0091] As shown in Figure 7, the travel HST 311 has a variable-displacement travel pump 311P and a variable-displacement travel motor 311M that are connected to each other via oil passages and form a common hydraulic circuit. The slewing HST 312 has a variable-displacement slewing pump 312P and a variable-displacement slewing motor 312M that are connected to each other via oil passages and form a common hydraulic circuit.

[0092] In the transmission 53, the transmission input shaft 52 is gear-connected to the pump shaft 331 of the travel pump 311P and the pump shaft 332 of the slewing pump 312P. A power distribution gear 333 is fixed to the transmission input shaft 52, and a travel input gear 334, which meshes with the power distribution gear 333, is fixed to the pump shaft 331 of the travel pump 311P. In addition, a slewing input gear 335, which meshes with the power distribution gear 333, is fixed to the pump shaft 332 of the slewing pump 312P.

[0093] In this configuration, the rotational power of the transmission input shaft 52 is transmitted to the pump shafts 331 and 332 of the travel pump 311P and the slewing pump 312P, respectively. In other words, the travel pump 311P and the slewing pump 312P are driven by power transmitted from the engine 25 via the first belt transmission mechanism 51 and the transmission input shaft 52. In the travel HST 311, the rotational power of the pump shaft 331 sends hydraulic fluid from the travel pump 311P to the travel motor 311M. Similarly, in the slewing HST 312, the rotational power of the pump shaft 332 sends hydraulic fluid from the slewing pump 312P to the slewing motor 312M.

[0094] A charge pump 337 is attached to the pump shaft 332 of the swivel pump 312P. The charge pump 337 is a pump for supplying hydraulic fluid to the travel pump 311P and the swivel pump 312P, as well as the travel motor 311M and the swivel motor 312M.

[0095] The travel HST311 is configured to arbitrarily adjust the rotation direction and rotation speed of the motor shaft of the travel motor 311M, which is the output shaft of the travel HST311, by changing the tilt angle of the rotating swash plate of the travel pump 311P in accordance with the amount of operation of the main shift lever 19 or the steering handle 18 (see Figure 2), thereby changing the discharge direction and discharge amount of hydraulic fluid to the travel motor 311M. Similarly, the slewing HST312 is configured to arbitrarily adjust the rotation direction and rotation speed of the motor shaft of the slewing motor 312M, which is the output shaft of the slewing HST312, by changing the tilt angle of the rotating swash plate of the slewing pump 312P in accordance with the amount of operation of the main shift lever 19 or the steering handle 18, thereby changing the discharge direction and discharge amount of hydraulic fluid to the slewing motor 312M.

[0096] As shown in Figure 7, the rotational power of the motor shaft of the travel motor 311M is transmitted to the auxiliary transmission mechanism 306 via a predetermined gear mechanism. The auxiliary transmission mechanism 306 is operated by an auxiliary transmission lever (not shown) provided in the driver's unit 15. The auxiliary transmission mechanism 306 performs multiple gear changes and neutral operations for the power generated by the travel HST 311.

[0097] The sub-transmission mechanism 306 has, for example, a sub-transmission shaft and a brake shaft, and between these shafts, a combination of a pair of gears supported on each shaft and capable of meshing with each other, consisting of a low-speed gear, a medium-speed gear, and a high-speed gear, and is configured to allow switching between high, medium, and low speeds as a multi-speed transmission. The sub-transmission mechanism 306 also has a neutral state as an operating state. The sub-transmission mechanism 306 is linked to the differential mechanism 307.

[0098] The differential mechanism 307 is an electric mechanism for transmitting driving force to a pair of left and right crawler sections 5, and is composed of a planetary gear group and has left and right output shafts. In the differential mechanism 307, the input driving force is output to the left and right output shafts via the planetary gear group and the like, and the rotational power of each output shaft is transmitted to the axle 308 by gears and the like. As a result, the drive sprocket 5a is driven to rotate, and the crawler section 5 is driven to move.

[0099] In the configuration described above, the main transmission lever 19 is operated to rotate the drive HST 311, and the left and right axles 308 are driven via the planetary gear group of the differential mechanism 307. This causes both axles 308 to rotate in the forward or reverse direction, and the left and right crawler sections 5,5 move in a straight line forward or backward. At this time, the auxiliary transmission lever is operated to drive the auxiliary transmission mechanism 306. In addition, the steering handle 18 is operated to rotate the turning HST 312, and the left and right axles 308 are driven via the planetary gear group of the differential mechanism 307. This causes each axle 308, which is in opposite directions, to rotate in the forward or reverse direction, and the crawler sections 5,5 turn or spin turn.

[0100] Thus, the combine harvester 1 is configured to perform forward and backward movement, turning, spin turns, etc., of the traveling machine body 2 by operating the steering handle 18, the main transmission lever 19, and the auxiliary transmission lever, while mechanically operating the traveling HST 311 and turning HST 312, etc., and transmitting mechanical power such as the differential mechanism 307, etc.

[0101] As described above, the combine harvester 1 includes a differential mechanism 307 that transmits power to the left and right drive sprockets 5a of the running section 4, a running HST 311 that receives power from the engine 25 and generates power to be transmitted to the differential mechanism 307, and a turning HST 312 that receives power from the engine 25 and also receives steering input from a steering handle 18 provided on the driver's section 15 and generates steering power to be transmitted to the differential mechanism 307. The combine harvester 1 also includes a sub-transmission mechanism 306 provided in the power transmission system between the running HST 311 and the differential mechanism 307.

[0102] As described above, the combine harvester 1 according to this embodiment includes an engine 25 mounted on the traveling body 2, a transmission 53 positioned at the front of the traveling body 2 that transmits driving force to the left and right crawler sections 5, 5, and a drive belt 323 for transmitting power from the engine 25 to the transmission 53. The drive belt 323 is wound around an engine output pulley 321 and a transmission input pulley 322, with the left-right direction of the machine body as its axial direction.

[0103] In this configuration, the combine harvester 1 is equipped with a cover unit 400 as a drive system protection unit, which is configured to cover and protect the drive belt 323. The cover unit 400 covers the drive belt 323 from at least one side.

[0104] The configuration of the cover unit 400 will be explained using Figures 8 to 15. As shown in Figures 8 to 15, the cover unit 400 has a protective cover 401, a lower guard 402, and a support bracket 403. The protective cover 401, the lower guard 402, and the support bracket 403 are fixed to each other to form an integrated cover unit 400.

[0105] The protective cover 401 will now be described. The protective cover 401 is a covering member that covers the drive belt 323 from at least one side. The protective cover 401 is a member formed by bending a plate-shaped member into a predetermined shape.

[0106] The protective cover 401 has a side cover portion 411 that covers the drive belt 323 from the left side, and a front cover portion 412 that covers the drive belt 323 from the front. The protective cover 401, with the side cover portion 411 and the front cover portion 412, is configured to be roughly L-shaped in plan view, forming a curved wall portion that covers the drive belt 323 from the left and front sides.

[0107] The side cover portion 411 is a substantially rectangular surface with the left-right direction as the plate thickness direction and the front-rear direction as the longitudinal direction, and is located to the left of the first belt transmission mechanism 51, which includes the drive belt 323. As shown in Figure 11, the front edge portion 411a of the side cover portion 411 is positioned in front of the front end of the transmission input pulley 322 in the front-rear direction. The rear edge portion 411b of the side cover portion 411 is positioned to the left of the front of the engine output pulley 321. Both the front edge portion 411a and the rear edge portion 411b of the side cover portion 411 are vertical edges that are aligned in the vertical direction.

[0108] As shown in Figure 11, the lower edge 411c of the side cover portion 411 is positioned at approximately the same height as the lower ends of the engine output pulley 321 and the transmission input pulley 322 in the vertical direction. Therefore, in a side view, the lower edge 411c of the side cover portion 411 is provided so as to follow (approximately coincide with) the lower path portion 323a of the drive belt 323, which is the front-to-back extending path portion between the lower ends of the engine output pulley 321 and the transmission input pulley 322. The lower edge 411c of the side cover portion 411 has a narrow lower bent surface portion 411f formed over approximately its entire length in the front-to-back direction, which is bent at a right angle inward (to the right) relative to the main body portion of the side cover portion 411.

[0109] Furthermore, as shown in Figure 11, the upper edge 411d of the side cover portion 411 is positioned at approximately the same height as the upper end of the transmission input pulley 322 in the vertical direction. The height of the upper end of the transmission input pulley 322 is above the rotation center of the engine output pulley 321 and slightly below the rotation center of the tension pulley 324. The upper edge 411d of the side cover portion 411 has an upper bent surface portion 411e formed over approximately its entire length in the front-rear direction, which is a narrow portion that is bent at a right angle to the left and right outward (left side) relative to the main body portion of the side cover portion 411. The lower edge 411c and upper edge 411d of the side cover portion 411 are both horizontal edges along the front-rear direction.

[0110] The lateral cover portion 411 described above covers almost the entire portion of the drive belt 323, excluding the portion wound around the engine output pulley 321, from the left side.

[0111] The front cover portion 412 is a substantially rectangular surface with the front-to-back direction as the plate thickness direction and the up-to-down direction as the longitudinal direction, and is located in front of the transmission input pulley 322. As shown in Figure 12, the front cover portion 412 has dimensions in the left-to-right direction that are slightly larger than the width dimension of the transmission input pulley 322, and covers the entire width of the drive belt 323 from the front. In the up-to-down direction, the front cover portion 412 has approximately the same dimensions as the side cover portion 411, and the height positions of both the upper and lower edges are approximately the same as the height positions of the upper edge portion 411d and the lower edge portion 411c of the side cover portion 411, respectively.

[0112] The front cover portion 412 has a vertical main body portion 412a in the middle of the vertical direction, with the front-to-back direction being the thickness direction, the upper end portion of the main body portion 412a being an upper inclined surface portion 412b, and the lower end portion of the main body portion 412a being a lower inclined surface portion 412c. The upper inclined surface portion 412b is an inclined surface portion that slopes downwards towards the front, and the lower inclined surface portion 412c is an inclined surface portion that slopes upwards towards the front. The upper and lower corners on the front side of the side cover portion 411 have a chamfered shape that aligns with the upper inclined surface portion 412b and the lower inclined surface portion 412c when viewed from the side. The main body portion 412a, together with the side cover portion 411, forms a right-angle corner.

[0113] The front cover portion 412 described above covers the roughly semi-circular portion of the drive belt 323 that is wound around the transmission input pulley 322, from the front.

[0114] As described above, the protective cover 401, which has a lateral cover portion 411 and a front cover portion 412, is configured to have the upper side of the drive belt 323 as the open side. That is, in a plan view, the protective cover 401 is provided so as to expose almost the entire portion of the first belt transmission mechanism 51, excluding the front end portion of the drive belt 323 (the front end portion of the transmission input pulley 322) that is covered by the upper inclined surface portion 412b of the front cover portion 412. In other words, the protective cover 401 has its upper side as the open side so as to expose almost the entire drive belt 323, which extends in the front-rear direction in a plan view, excluding the front end portion covered by the upper inclined surface portion 412b.

[0115] The lower guard 402 will now be described. The lower guard 402 is a covering member (belt guard) provided on the underside of the drive belt 323 and protecting the drive belt 323 from below. The lower guard 402 is a member formed by bending a plate-shaped member into a predetermined shape.

[0116] The lower guard 402 is the part that forms the bottom surface of the cover unit 400, and in a plan view, it is provided so as to occupy almost the entire area, excluding the rear end, of the roughly rectangular area along which the roughly L-shaped protective cover 401 follows (see Figure 12). The lower guard 402 is provided in an inclined manner in the front-rear direction of the aircraft. In this embodiment, the lower guard 402 as a whole is provided in an inclined manner that slopes slightly downward towards the rear.

[0117] The lower guard 402 has a width dimension that is approximately the same as the left-right dimension of the front cover portion 412 of the protective cover 401, except for its rear end. The lower guard 402 has approximately the same dimensions as the side cover portion 411 of the protective cover 401 in the front-rear direction. In the front-rear direction, the front end of the lower guard 402 is positioned approximately at the same position as the main body portion 412a of the front cover portion 412, and the rear end is positioned forward of the rear end of the side cover portion 411, and approximately at the same position as the front end of the engine output pulley 321.

[0118] The lower guard 402 has a lower guard body portion 421 which makes up the majority of the lower guard 402, a front support surface portion 422 provided on the front side of the lower guard body portion 421, and a rear support surface portion 423 provided on the rear side of the lower guard body portion 421.

[0119] The lower guard body 421 is a roughly rectangular plate-like portion with its longitudinal direction in the front-to-back direction, and has a slightly downward sloping surface. The angle of inclination of the lower guard body 421 with respect to the horizontal direction is, for example, about 5°. Side walls 424 are formed by bending on both the left and right sides of the lower guard body 421. The side walls 424 are portions that rise perpendicularly upward from the lower guard body 421 and are formed over the entire length of the lower guard body 421 in the front-to-back direction. The height dimension of the side walls 424 is sufficiently small compared to the left-to-right dimension of the lower guard body 421.

[0120] The front support surface portion 422 is a roughly rectangular plate-like portion, formed by bending upward from the front side of the lower guard body portion 421 so as to form an obtuse angle with the lower guard body portion 421 in a side view. In a side view, the front support surface portion 422 forms an upward-sloping surface portion that follows the slope of the lower inclined surface portion 412c of the front cover portion 412. In a plan view, the front support surface portion 422 has dimensions of approximately 1 / 5 of the lower guard body portion 421 in the front-rear direction.

[0121] The rear support surface 423 is a surface that extends the lower guard body 421 to the rear and has an overhang 423a that protrudes to the right. The rear support surface 423 has the same left-right dimension at its front end as the width dimension of the lower guard body 421, while the left-right dimension at its rear end is larger than the left-right dimension at its front end by the overhang dimension of the overhang 423a. The rear support surface 423 is a surface that extends horizontally from the rear side of the lower guard body 421 toward the rear and is formed as a surface that is slightly bent relative to the lower guard body 421. In a plan view, the rear support surface 423 has a dimension of approximately 1 / 5 of the lower guard body 421 in the front-rear direction.

[0122] The lower guard 402 fixes its front support surface 422 to the downward inclined surface 412c of the front cover portion 412 of the protective cover 401. The front support surface 422 overlaps the downward inclined surface 412c from above and is fixed to the downward inclined surface 412c by bolts 425. The bolts 425 pass through the downward inclined surface 412c and the front support surface 422 from below and are screwed into nuts 426 provided on the upper side of the front support surface 422. The fixing points by the bolts 425 are provided at two locations on the left and right of the front end of the front support surface 422. The downward inclined surface 412c of the protective cover 401 has holes 412d formed at two locations on the left and right for the bolts 425 to pass through (see Figure 13). In addition, the front end of the front support surface 422 has holes 422a formed at two locations on the left and right for the bolts 425 to pass through (see Figure 14).

[0123] Furthermore, the lower guard 402 is connected and fixed to the protective cover 401 via support stays 427 provided at two locations, front and rear. The support stays 427 are rectangular plate-shaped members with the vertical direction as the longitudinal direction and the horizontal direction as the thickness direction, and their lower ends are fixed to the left end of the lower guard body 421.

[0124] In detail, the support stay 427 has a bent portion 427a at its lower end, forming a right-angle corner. The bent portion 427a is a portion of the support stay 427 that is bent at a right angle to the right relative to the main body portion. The support stay 427 aligns the right-angle shape formed by the bent portion 427a inward with the right-angle shape formed by the lower guard main body portion 421 and the left side wall portion 424, and is fixed to each surface portion of the lower guard main body portion 421 and the side wall portion 424 by welding or the like. The two support stays 427 extend upward from the left side wall portion 424. In the front-rear direction, the front support stay 427 is located near the front end of the lower guard main body portion 421, and the rear support stay 427 is located near the rear end of the lower guard main body portion 421.

[0125] The support stay 427 is located on the inside (right side) of the lateral cover portion 411 relative to the protective cover 401 and is fixed by a bolt 428. The bolt 428 passes through the lateral cover portion 411 and the support stay 427 from the left side and is screwed into a nut portion 429 provided on the right side of the support stay 427. Each support stay 427 has two fixing points by the bolt 428, one at the top and one at the bottom.

[0126] The support stay 427 has two holes 427b formed at the top and bottom for passing bolts 428 through (see Figure 14). In addition, holes 411g are formed in the side cover portion 411 at positions corresponding to the holes 427b of each support stay 427 for passing bolts 428 through (see Figure 13). Furthermore, a notch 411h is formed in the lower bent surface portion 411f of the side cover portion 411 to avoid interference with the front and rear support stays 427 (see Figure 13).

[0127] The lower guard 402 has its main body 421 positioned below the side cover portion 411 of the protective cover 401, and a gap 430 is formed between the side cover portion 411 and the lower guard 402, exposing the lower parts of the front and rear support stays 427. In a configuration where the lower edge portion 411c of the side cover portion 411 extends horizontally in the front-to-back direction, and the lower guard 402 is inclined downwards towards the rear, the gap 430 gradually increases in vertical distance from the front to the rear when viewed from the side (see Figure 11).

[0128] As described above, the lower guard 402 has its front support surface 422 fixed to the front cover portion 412 of the protective cover 401, and its lower guard body portion 421 is connected and fixed to the lateral cover portion 411 via the front and rear support stays 427. As a result, in the cover unit 400, the protective cover 401 and the lower guard 402 are integrally configured with each other. In other words, the lower guard 402 is connected and fixed to the protective cover 401, and together with the protective cover 401, they form an integrated cover body.

[0129] The support bracket 403 will now be described. The support bracket 403 is a support member that fixes and supports the cover unit 400 with respect to the transmission 53. The support bracket 403 is a member formed by bending a plate-shaped member having a predetermined shape to form a right-angle corner. The support bracket 403 has a fixing surface portion 431 and a support surface portion 432 as surfaces that form a right-angle corner.

[0130] The fixed surface portion 431 is a narrow, elongated, roughly rectangular section, with its longitudinal direction oriented in the front-to-back direction in a plan view. The fixed surface portion 431 is the surface portion of the support bracket 403 that is fixed to the lower guard 402.

[0131] The support surface portion 432 has a base portion 432a that forms a right-angle corner with the fixed surface portion 431, and an arm portion 432b that protrudes from the base portion 432a (see Figure 15). The base portion 432a is a longitudinal portion formed over the entire longitudinal range of the fixed surface portion 431. The arm portion 432b is a projection that protrudes downward from the middle of the longitudinal portion of the base portion 432a. The support surface portion 432 has an outer shape that is approximately T-shaped in side view due to the base portion 432a and the arm portion 432b.

[0132] The support bracket 403 fixes its fixed surface portion 431 to the front support surface portion 422 of the lower guard 402. The fixed surface portion 431 overlaps the front support surface portion 422 from below and is fixed to the front support surface portion 422 by bolts 435. The bolts 435 pass through the fixed surface portion 431 and the front support surface portion 422 from below and are screwed into nuts 436 provided on the upper side of the front support surface portion 422 (see Figure 11). The fixing portion by bolts 435 is located behind the fixing portion of the lower guard 402 to the protective cover 401 (the fixing portion by bolts 425), and is provided at two locations, front and rear, at the front end of the fixed surface portion 431. Holes 431a for passing bolts 435 are formed at the front end of the fixed surface portion 431 of the support bracket 403 and in its vicinity, at two locations, front and rear (see Figure 15). Furthermore, the front support surface 422 of the lower guard 402 has holes 422b formed at the front and rear for passing bolts 435 through (see Figure 14).

[0133] The mounting structure of the cover unit 400 will now be described. The cover unit 400 is mounted with both the front and rear sides fixedly supported to the vehicle body 2. On the front side, the support bracket 403 is fixedly supported to the transmission case 303 of the transmission 53, and on the rear side, the lower guard 402 is fixedly supported to the chassis 305 of the vehicle body 2.

[0134] In the cover unit 400, the lower guard 402 is provided in an extensional manner in the longitudinal direction of the machine, with its front end supported by the transmission 53 via a support bracket 403 and its rear end supported by the chassis 305 of the running machine 2.

[0135] The front support portion of the cover unit 400 will now be described. The cover unit 400 has a support bracket 403 positioned on the left side of the transmission case 303 and is fixed to the transmission case 303 by fixing bolts 441. The fixing portion by the fixing bolts 441 is provided at two locations on the support bracket 403: the rear end of the base portion 432a of the support surface portion 432 and the tip of the arm portion 432b.

[0136] The support bracket 403 is fastened to the transmission case 303 together with the brake wire stay 443, which supports the brake wire 442, by fixing bolts 441. The brake wire stay 443 is made of a plate-shaped member and is located on the left side of the transmission case 303 and overlaps the support surface portion 432 of the support bracket 403 from the right side.

[0137] The brake wire stay 443 has a support projection 443a at its upper end, which is bent at a right angle to the left relative to the stay body, to support the brake wire 442. The support projection 443a securely supports the brake wire 442 by passing through one end of the brake wire 442.

[0138] One end of the brake wire 442 is rotatably connected to the brake arm 446 via a roughly U-shaped connecting fitting 445. The brake arm 446 is an operating arm for operating the brake, which is provided on the brake shaft that constitutes the sub-transmission mechanism 306 (see Figure 7). The brake is covered by a brake cover 447 attached to the left side of the transmission case 303 by bolts or the like, and the brake arm 446 is provided on the left side of the brake cover 447. The brake arm 446 is supported at its rear base end so as to be rotatable in the left-right direction as its axial direction, and at its front tip end it is connected to the connecting fitting 445.

[0139] The fixing bolt 441 that secures the support bracket 403 passes through the support surface portion 432 of the support bracket 403, the brake wire stay 443, and the brake cover 447 from the left side and is screwed into the transmission case 303. Holes 432c are formed in two places on the support surface portion 432 of the support bracket 403, at the rear end of the base portion 432a and at the tip of the arm portion 432b, through which the fixing bolt 441 passes (see Figure 15).

[0140] The other end of the brake wire 442 is connected to a predetermined operating member for brake operation provided in the driver unit 15. By operating the operating member, the brake arm 446 is rotated, the brake is activated, restricting the rotation of the brake shaft of the auxiliary transmission mechanism 306, and braking the transmission of power to the drive sprocket 5a.

[0141] The rear support portion of the cover unit 400 will now be described. The cover unit 400 fixes the rear support surface portion 423 of the lower guard 402 to a pipe-shaped member 451, which is a frame member constituting the chassis 305. The pipe-shaped member 451 is a hollow cylindrical member that extends in the left-right direction of the machine.

[0142] The pipe-shaped member 451 is provided with a support base portion 452, which serves as the mounting base for the lower guard 402. The support base portion 452 is the part that forms the mounting seat for the lower guard 402 on the pipe-shaped member 451, and has a horizontal support surface portion 452a and left and right side portions 452b. The support base portion 452 is provided by fixing a bent plate-shaped member that is roughly U-shaped with the lower side open to the pipe-shaped member 451. The members constituting the support base portion 452 are fixed to the pipe-shaped member 451 by welding or the like, with the upper part of the pipe-shaped member 451 fitted into semicircular recesses formed in the left and right side portions 452b.

[0143] The lower guard 402 is fixed to the support base 452 by fixing bolts 453, with its rear support surface 423 positioned above the support surface 452a of the support base 452. The fixing points by the fixing bolts 453 are provided at two locations on the left and right sides of the rear of the rear support surface 423. Between the support surface 452a of the support base 452 and the rear support surface 423 of the lower guard 402, the plate-shaped portion 455a of the frame member 455 that constitutes the chassis 305 is interposed (see Figure 11). The frame member 455 is a bent plate-shaped member with a roughly L-shaped cross-section and extending in the left-right direction of the machine, with the horizontal surface portion being the plate-shaped portion 455a. Note that, for convenience, the frame member 455 is not shown in Figures 8 to 10.

[0144] The fixing bolt 453 passes through the rear support surface 423 of the lower guard 402, the plate-shaped portion 455a of the frame member 455, and the support surface 452a of the support base portion 452 from above, and is screwed into a nut 456 located below the support surface 452a. At the rear of the rear support surface 423 of the lower guard 402, there are two notched recesses 423b, with the rear side open, formed on the left and right sides to allow the fixing bolt 453 to pass through (see Figure 14). The recess 423b on the right side is formed in the protruding portion 423a of the rear support surface 423.

[0145] In this embodiment of the combine harvester 1 having the above configuration, the combination harvester 1, which has a transmission 53 located at the front of the traveling body 2, is equipped with a cover unit 400, which protects the components around the transmission 53 from foreign objects. In this embodiment, it is possible to prevent foreign objects from coming into contact with the drive belt 323 for transmitting power to the transmission 53, thereby suppressing the occurrence of malfunctions such as the drive belt 323 coming off or being damaged.

[0146] In the combine harvester 1, a protective cover 401 is provided around the drive belt 323, covering the drive belt 323 from at least one side. With this configuration, it is possible to prevent foreign objects such as crops to be harvested (harvested produce) or stalk residues from entering the drive belt 323, thereby preventing the drive belt 323 from coming off or being damaged.

[0147] In particular, during the harvesting of corn, which has thicker stalks than rice or wheat, harvested crops and their remaining stalks can scatter and fall into the drive belt 323, or collide with the drive belt 323. In some cases, foreign objects can get caught between the drive belt 323 and the pulley, leading to malfunctions such as the drive belt 323 coming off or being damaged. Therefore, with a configuration that includes a protective cover 401, the drive belt 323 can be protected from foreign objects by the protective cover 401, preventing foreign objects from entering the drive belt 323 or coming into contact with the drive belt 323, thereby preventing malfunctions of the drive belt 323.

[0148] Furthermore, the protective cover 401 is configured to have an open side above the drive belt 323. With this configuration, the protective cover 401 can protect the drive belt 323 from the front, sides, etc., and also allows easy access to the drive belt 323 from above, thus ensuring maintainability of the first belt transmission mechanism 51, including the drive belt 323. In addition, in a configuration where the tension pulley 324 is positioned above the drive belt 323, as in this embodiment, the protective cover 401 can be installed without interfering with the operation of the tension pulley 324.

[0149] In this embodiment, the protective cover 401 is configured with the upper side of the drive belt 323 open, and has a side cover portion 411 that covers the drive belt 323 from the side (left side) and a front cover portion 412 that covers the drive belt 323 from the front. With this configuration, it is possible to effectively prevent the intrusion or collision of corn stalks, residues, etc., with the drive belt 323 from the front and sides when the machine is moving forward. Regarding the coverage area of ​​the protective cover 401, the protective cover 401 is provided such that the height of the upper edges of the side cover portion 411 and the front cover portion 412 is approximately 800 mm above the ground, corresponding to the height of corn stalks, for example, which are approximately 800 mm above the ground.

[0150] Furthermore, the combine harvester 1 is equipped with a lower guard 402 located below the drive belt 323 as a configuration to protect the drive belt 323. With this configuration, for example, during harvesting operations by the combine harvester 1, it is possible to prevent the drive belt 323 from being pushed up from below by corn stalks or other foreign objects, and thus protect the drive belt 323 from foreign objects from below, thereby effectively preventing the drive belt 323 from coming off or being damaged.

[0151] Furthermore, the protective cover 401 and the lower guard 402 are integrally constructed with respect to each other. With this configuration, the drive belt 323 can be protected, and the protective cover 401 and the lower guard 402 can be easily attached to and detached from the machine body, thus providing good maintainability for the first belt transmission mechanism 51. In particular, in this embodiment, the protective cover 401 and the lower guard 402 together with the support bracket 403 constitute an integrated cover unit 400, and with this configuration, good attachment and detachment to the machine body can be obtained.

[0152] Furthermore, the lower guard 402 is provided in an extensional manner in the longitudinal direction of the machine, with its front end supported by the transmission 53 via a support bracket 403, and its rear end supported by the chassis 305 of the running machine 2. With this configuration, the lower guard 402 can be installed in a stable state by utilizing the existing configuration.

[0153] Furthermore, the lower guard 402 is provided in a downward sloping manner towards the rear in the front-rear direction of the machine. With this configuration, even if foreign matter such as harvested crops or remaining stalks lands on the lower guard 402, the slope of the lower guard 402 guides the foreign matter to the rear, thereby preventing the foreign matter from accumulating on the lower guard 402. This prevents the drive of the drive belt 323 from being obstructed by the foreign matter, and prevents the foreign matter from igniting due to excessive friction caused by the rotation of the drive belt 323, thereby ensuring a smooth and safe operation of the drive belt 323. In this embodiment, the lower guard 402 is provided in a downward sloping manner towards the rear in the front-rear direction of the machine, but it may also be provided in a downward sloping manner towards the front.

[0154] [Diagram of the cover unit] The following describes a modified configuration of the cover unit 400 according to this embodiment. The modified configuration of the cover unit 400 described below is a modification of the lower guard 402.

[0155] (Variation 1) As shown in Figure 16, in the cover unit 400A of the modified example 1, the lower guard 402 is provided in an inclined manner in the left-right direction of the machine. In the example shown in Figure 16, the lower guard body portion 421 of the lower guard 402 is provided so as to form a downward sloping surface to the right. That is, the lower guard body portion 421 is provided so as to have its upper surface 421a as a downward sloping surface to the right.

[0156] In the example shown in Figure 16, the inclination angle θ1 that the upper surface 421a of the lower guard body 421 makes with respect to the horizontal plane H1 in a front view of the aircraft is approximately 15 to 20 degrees. However, the magnitude of the inclination angle θ1 is not particularly limited.

[0157] In the configuration of Modified Example 1, the bent portion 427a that the support stay 427 has at its lower end as a fixing portion to the lower guard body portion 421 is formed as a downward sloping surface portion that forms an obtuse angle with the main body portion of the support stay 427, in accordance with the inclination of the lower guard body portion 421.

[0158] According to the configuration of Modified Example 1, even if foreign objects such as harvested crops or remaining stalks land on the lower guard body 421 of the lower guard 402, the inclination of the lower guard body 421 allows the foreign objects to fall from one side (right side), thus preventing them from accumulating on the lower guard 402. This prevents foreign objects from obstructing the drive of the drive belt 323 or from igniting due to excessive friction caused by the rotation of the drive belt 323, thereby ensuring smooth and safe operation of the drive belt 323. In this embodiment, the lower guard body 421 is provided with a downward slope to the right in the left-right direction of the machine, but it may also be provided with a downward slope to the left.

[0159] (Modification 2) As shown in Figure 17, the lower guard 402 of the modified cover unit 2 has an opening 460 for discharging foreign matter. The opening 460 is formed through multiple locations in the lower guard body portion 421 of the lower guard 402.

[0160] In the example shown in Figure 17, the rectangular lower guard body 421, with its longitudinal direction in the front-to-back direction, has six elongated or slit-shaped openings 460 formed in the longitudinal direction in the front-to-back direction. Specifically, three openings 460 are formed in the front and rear of the lower guard body 421, each spaced at predetermined intervals in the left-to-right direction.

[0161] According to the configuration of Modified Example 2, even if foreign matter (impurities) such as harvested crops or remaining stalks lands on the lower guard body 421 of the lower guard 402, the foreign matter can be dropped and discharged through the opening 460, thereby preventing foreign matter from accumulating on the lower guard 402. This prevents foreign matter from obstructing the drive of the drive belt 323 or from igniting due to excessive friction caused by the rotation of the drive belt 323, thereby ensuring smooth and safe operation of the drive belt 323. Note that the shape and number of openings 460 are not limited to the example shown in Figure 17.

[0162] (Variation 3) As shown in Figures 18 and 19, in the modified example 3 cover unit 400B, the lower guard 402 has a gap 470 for discharging foreign matter. The gap 470 is formed by a plurality of pipe sections 471 installed between the front support surface 422 and the rear support surface 423 in the lower guard 402.

[0163] The pipe section 471 is provided by fixing a straight pipe member having a circular cross-section to the front support surface 422 and the rear support surface 423, respectively, by welding or the like, along the front-to-back direction. In the example shown in Figures 18 and 19, four pipe sections 471 are provided at predetermined intervals in the left-to-right direction in the left-to-right intermediate section of the lower guard body 421.

[0164] On both the left and right sides of the lower guard body portion 421, a left flat plate portion 421b and a right flat plate portion 421c are formed, which are perpendicular surfaces together with the side wall portion 424. The left flat plate portion 421b has a width that supports the bent portion 427a of the support stay 427. In other words, while the lower guard body portion 421 of the lower guard 402 shown in Figure 14 is a flat plate portion overall, in the configuration of the modified example 3, the left and right intermediate portions of the lower guard body portion 421, excluding both edges in the width direction (left and right direction), are formed by a plurality of pipe portions 471 arranged at predetermined intervals in the left and right direction.

[0165] In this configuration, gaps 470 are formed between adjacent pipe sections 471 on the left and right, between the pipe section 471L located at the left end and the left flat plate section 421b, and between the pipe section 471R located at the right end and the right flat plate section 421c. The gaps 470 are slit-shaped openings that are long in the front-to-back direction.

[0166] According to the configuration of Modified Example 3, even if foreign matter (impurities) such as harvested crops or remaining stalks lands on the lower guard body portion 421 of the lower guard 402, the foreign matter can be dropped and discharged through the gap 470, thereby preventing foreign matter from accumulating on the lower guard 402. This prevents foreign matter from hindering the drive of the drive belt 323 or from igniting due to excessive friction associated with the rotation of the drive belt 323, thereby ensuring smooth and safe operation of the drive belt 323. Note that the number and shape (cross-sectional shape, etc.) of the pipe portions 471 forming the gap 470 are not limited to the examples shown in Figures 18 and 19. Furthermore, the surface structure of the lower guard body portion 421 having a gap for discharging impurities may be, for example, a grid-like structure or a mesh-like structure.

[0167] [Second Embodiment] A second embodiment of the present invention will now be described. In each embodiment described below, the same names or reference numerals will be used for components that are common to or correspond to those in the first embodiment, and explanations of redundant content will be omitted as appropriate.

[0168] In combine harvesting operations, as the machine moves forward, foreign objects such as harvested crops and stalk residues can collide with the front of the transmission, or scattered foreign objects can accumulate on the front of the transmission, leading to malfunctions, damage, and other problems with the equipment components located on the front of the transmission.

[0169] In particular, during the harvesting of corn, which has thicker stalks than rice or wheat, corn and its remaining stalks can collide with the front of the transmission or accumulate as residue, which can easily cause malfunctions in the equipment configuration located on the front of the transmission.

[0170] Therefore, the combine harvester according to this embodiment aims to suppress the occurrence of malfunctions in the device configuration located on the front side of the transmission by providing a protective cover that constitutes a drive system protection unit on the front side of the transmission.

[0171] The combine harvester 1 according to this embodiment includes a drivetrain protection unit 700, which is configured to cover and protect the transmission 53. The drivetrain protection unit 700 has a protective cover 500 provided on the front side of the transmission 53.

[0172] The configuration of the protective cover 500 will be explained using Figures 20 to 31. In Figures 22 and 23, the area covered by the protective cover 500 is indicated by hatching. As shown in Figures 20 to 23, the protective cover 500 is provided on the front upper part of the transmission 53, which includes the transmission body 301 and the HST section 302 provided above it.

[0173] The protective cover 500 has its upper end positioned at approximately the same height as the upper surface of the HST case 313 of the HST section 302, which forms the upper surface of the transmission 53, in the vertical direction. The protective cover 500 also has its lower end positioned approximately in the center of the transmission 53 in the vertical direction. In the horizontal direction, the protective cover 500 is provided to cover approximately the entire area between the left and right protruding case sections 303a of the transmission 53. In the front-rear direction, the protective cover 500 is provided in front of the transmission input pulley 322, and is provided to cover the part of the transmission 53 in front of the transmission input pulley 322.

[0174] The protective cover 500 has a cover body portion 501 that covers the transmission 53 and a support arm portion 502 that supports the protective cover 500 relative to the transmission 53. In other words, the protective cover 500 is a covering member that covers a part of the transmission 53 mainly from the front side with the cover body portion 501, and is provided on the front side of the transmission 53 while being supported by the support arm portion 502, etc.

[0175] The protective cover 500 has a cover body 501 which includes a front cover portion 503 that covers the transmission 53 from the front and a side cover portion 504 that covers the transmission 53 from the left side, which is one of the left or right sides. The cover body 501 is mainly composed of a right cover member 505 which constitutes the front cover portion 503 and a left cover member 506 which constitutes the side cover portion 504. The right cover member 505 and the left cover member 506 are fixed to each other to form an integrated cover body 501.

[0176] The right cover member 505 will now be described. The right cover member 505 is a member formed by bending a plate-shaped member into a predetermined shape, and has multiple surfaces. The right cover member 505 has a front cover surface 511, an upper cover surface 512, a right side cover surface 513, and a lower cover surface 514, and these surfaces give it a roughly box-like outer shape with the rear and left sides open.

[0177] The front cover surface portion 511 is a roughly trapezoidal plate-shaped portion with the thickness direction roughly oriented in the front-to-back direction. The front cover surface portion 511 has as its outer edges an upper edge portion 511a that runs in the left-to-right direction, a left edge portion 511b and a right edge portion 511c that are parallel to each other and run in the up-to-down direction when viewed from the front, and a downward sloping edge portion 511d that slopes downward to the left. In this embodiment, the angle that the downward sloping edge portion 511d makes with respect to the horizontal direction when viewed from the front is about 20°. The front cover surface portion 511 constitutes the majority of the front cover portion 503 of the cover body portion 501.

[0178] The upper cover surface portion 512 is a roughly rectangular plate-shaped portion with the thickness direction roughly in the vertical direction and the longitudinal direction in the horizontal direction. The upper cover surface portion 512 extends rearward from the upper edge portion 511a of the front cover surface portion 511 so as to form a right-angle corner with the front cover surface portion 511. In this embodiment, the width dimension (roughly in the front-to-back direction) of the upper cover surface portion 512 is approximately 1 / 5 of the left-to-right dimension of the front cover surface portion 511. The upper cover surface portion 512 is provided in a range of roughly half to the right of the upper edge portion 511a of the front cover surface portion 511. The upper cover surface portion 512 forms a part of the upper surface portion of the cover body portion 501.

[0179] The right-side cover surface 513 is a roughly rectangular plate-shaped portion with the left-right direction as the plate thickness direction and the roughly vertical direction as the longitudinal direction. The right-side cover surface 513 extends rearward from the right side 511c of the front cover surface 511 so as to form a right-angle corner with the surfaces of the front cover surface 511 and the upper cover surface 512. The width dimension (roughly in the front-rear direction) of the right-side cover surface 513 is approximately the same as the width dimension of the upper cover surface 512. The right-side cover surface 513 is provided over approximately the entire area of ​​the right side 511c of the front cover surface 511, excluding the lower end. The right-side cover surface 513 forms the right side of the cover body 501.

[0180] The lower cover surface 514 is a roughly trapezoidal plate-shaped portion, with the thickness direction being approximately perpendicular to the inclination direction of the lower inclined edge 511d of the front cover surface 511 when viewed from the front, and the longitudinal direction being the same inclination direction. The lower cover surface 514 has a shape in which the width (approximately front-to-back direction) dimension (extension dimension from the front cover surface 511 to the rear) gradually increases from the right side (upper side) to the left side (lower side). The lower cover surface 514 extends rearward from the lower inclined edge 511d of the front cover surface 511 so as to form a right-angle corner with the front cover surface 511. At the right edge of the lower cover surface 514, the width dimension is approximately the same as the front-to-back dimension of the upper cover surface 512. The lower cover surface 514 is provided over approximately the entire range of the lower inclined edge 511d of the front cover surface 511. The lower cover surface portion 514 forms part of the lower surface portion of the cover body portion 501.

[0181] The left cover member 506 will now be described. The left cover member 506 is a member formed by bending a plate-shaped member into a predetermined shape, and has multiple surfaces. The left cover member 506 has a front inclined cover surface 521, an upper cover surface 522, a left side cover surface 523, a lower cover surface 524, and a front surface 525, and these surfaces give it a roughly box-like outer shape with the rear and right sides open.

[0182] The front-sloping cover surface portion 521 is a surface portion that is inclined with respect to the front-rear direction in a plan view, with its outer surface facing diagonally forward to the left, and is a substantially rectangular plate-shaped portion with its longitudinal direction substantially in the vertical direction. The front-sloping cover surface portion 521 has as its outer edges an upper edge portion 521a and a lower edge portion 521d which are parallel to each other and aligned in the left-right direction in a front view, and a left edge portion 521b and a right edge portion 521c which are parallel to each other and aligned in the vertical direction in a front view. In this embodiment, the angle that the front-sloping cover surface portion 521 makes with respect to the front-rear direction in a plan view is substantially 45°. The front-sloping cover surface portion 521 constitutes the front part of the side cover portion 504 of the cover body portion 501.

[0183] The upper cover surface 522 is a plate-like portion with its thickness oriented approximately vertically. The upper cover surface 522 forms a right-angle corner with the front inclined cover surface 521, the left side cover surface 523, and the front surface 525. The upper cover surface 522 has edges that form its outer shape, including edges along the upper edges of the front inclined cover surface 521, the left side cover surface 523, and the front surface 525, a rear edge along the left-right direction, and a right edge along the approximately front-back direction, forming an approximately pentagonal shape. The upper cover surface 522 forms a part of the upper surface of the cover body 501.

[0184] The left-side cover surface 523 is a roughly rectangular plate-shaped portion with the left-right direction as the plate thickness direction and the roughly vertical direction as the longitudinal direction. The left-side cover surface 523 extends rearward from the left side portion 521b of the front-sloping cover surface 521 and forms a right-angle corner together with the upper cover surface 522. The width dimension of the left-side cover surface 523, which is a dimension along the roughly front-rear direction, is approximately the same as the width dimension of the front-sloping cover surface 521 (the dimension of the upper side portion 521a). The left-side cover surface 523 is provided over the entire range relative to the left side portion 521b of the front-sloping cover surface 521. The left-side cover surface 523 forms the left side of the cover body portion 501, and the left-side cover surface 523 constitutes the rear part of the side cover portion 504 of the cover body portion 501.

[0185] The lower cover surface 524 is a plate-shaped portion with its thickness oriented approximately vertically, and is a surface facing the upper cover surface 522. The lower cover surface 524, together with the front inclined cover surface 521, the left side cover surface 523, and the front surface 525, forms a right-angle corner and has approximately the same shape as the upper cover surface 522. The lower cover surface 524 forms part of the lower surface of the cover body 501.

[0186] The front portion 525 is a roughly rectangular plate-shaped section with the thickness direction roughly oriented in the front-to-back direction. The front portion 525 extends to the right from the right side portion 521c of the front inclined cover surface portion 521 and forms a right-angle corner together with the surfaces of the upper cover surface portion 522 and the lower cover surface portion 524. The front portion 525 is narrower than the front inclined cover surface portion 521, etc. In this embodiment, the width (left-to-right direction) dimension of the front portion 525 is approximately 1 / 3 of the width dimension of the front inclined cover surface portion 521. The front portion 525 is provided over the entire range relative to the right side portion 521c of the front inclined cover surface portion 521.

[0187] The left cover member 506, having the configuration described above, is fixed to the right cover member 505 by fixing bolts 516 and 536, with its front portion 525 overlapping the left end of the front cover surface portion 511 of the right cover member 505 from the rear. The fixing bolts 516 and 536 pass through the front cover surface portion 511 and the front portion 525 from the front and are screwed into nuts 517 and 535 provided on the rear side of the front portion 525.

[0188] The fixing points using fixing bolts 516 and 536 are provided at two locations near the upper and lower ends of the front portion 525 of the left cover member 506. The front cover surface 511 of the right cover member 505 and the front portion 525 of the left cover member 506 each have holes 511e and 525e formed at two locations, upper and lower, through which the fixing bolts 516 and 536 pass. Of the two fixing points, the lower fixing point using fixing bolt 536 also serves as the fixing point for the support arm portion 502, as will be described later.

[0189] As described above, in the cover body 501 composed of the right cover member 505 and the left cover member 506, the left cover member 506 extends rearward relative to the right cover member 505 in the front-rear direction. More specifically, in the front-rear direction, the left cover member 506 has its left edge portion 521b, which is the rear edge portion of the front inclined cover surface portion 521, positioned rearward from the rear end of the lower cover surface portion 514 of the right cover member 505, and the left side cover surface portion 523 extends rearward from the left edge portion 521b of the front inclined cover surface portion 521. In the left cover member 506, the position of the rear edge portion of the upper cover surface portion 522 is aligned with the position of the rear end portion (rear upper corner) of the left side cover surface portion 523.

[0190] Furthermore, in the cover body portion 501, the upper cover surface portion 522 of the left cover member 506 is parallel to the upper cover surface portion 512 of the right cover member 505 and is located slightly above the upper cover surface portion 512. Because there is a non-formed portion of the upper cover surface portion 512 on the left side of the upper edge portion 511a of the front cover surface portion 511, in a plan view, the upper cover surface portion 512 of the right cover member 505 and the front portion of the upper cover surface portion 522 of the left cover member 506 face each other in the left-right direction via a notched gap 526.

[0191] Furthermore, in the cover body portion 501, the lower cover surface portion 514 of the right cover member 505 abuts the left (lower) edge of the lower cover surface portion 524 of the left cover member 506, separated by a small slit-shaped gap 527. Therefore, the left edge of the lower cover surface portion 514 is located at approximately the same height as the lower cover surface portion 524.

[0192] The cover body 501 is positioned such that it is slightly tilted backward when the protective cover 500 is attached to the transmission 53 (see Figure 23). That is, the cover body 501 has a rectangular shape when viewed from the left side, and this rectangular shape is positioned such that it is slightly tilted backward (tilting towards the rear) with respect to the vertical direction. In this embodiment, the angle that the longitudinal direction of the cover body 501 (the direction along which the front cover surface 511 follows) makes with respect to the vertical direction in a side view is approximately 5°. However, the tilt angle of the cover body 501 in a side view is not limited, and the cover body 501 may also be positioned along the vertical direction (without tilting).

[0193] Furthermore, the protective cover 500 is configured to have an open side at the bottom. The protective cover 500 has an open section 530 covering most of the outer shape of the cover body 501 in a plan view, with the lower surface of the cover body 501 formed by the lower cover surface 514 of the right cover member 505 and the lower cover surface 524 of the left cover member 506 (see Figure 25).

[0194] Specifically, as shown in Figure 25, with respect to the outer shape range of the cover body 501 in a plan view, represented by the first virtual straight line L1 and the second virtual straight line L2 shown by the dashed-dot line, the lower surface of the cover body 501 has an open portion 530 for most of its rear side. With respect to the outer shape range of the cover body 501 in a plan view, the first virtual straight line L1 is a straight line along the front-rear direction, extending rearward from the position of the outer surface of the right side cover surface 513 of the right cover member 505. Also, with respect to the same outer shape range, the second virtual straight line L2 is a straight line along the left-right direction, extending to the right from the position of the rear end of the upper cover surface 522 of the left cover member 506. The first virtual straight line L1 and the second virtual straight line L2 are perpendicular to each other.

[0195] In other words, the first virtual line L1 is a line that defines the position of the right end of the outer shape range of the cover body 501 in a plan view, the second virtual line L2 is a line that defines the position of the rear end of the same outer shape range, and the positions of the outer edges on other sides of the same outer shape range (front side, left side, etc.) are defined by the surfaces that make up the outer shape of the cover body 501 in a plan view. Therefore, the outer shape range of the cover body 501 in a plan view is defined as a roughly rectangular area with a chamfered left front corner.

[0196] Furthermore, the lower surface of the cover body 501 is divided into two parts: the lower cover surface 514 occupies the right front area, and the lower cover surface 524 occupies the left front area, with the remaining rear portion being an open area 530, which is an area not covered by the surfaces of each component (where no surfaces exist). The open area 530 connects the inside of the cover body 501 (the space enclosed by the cover body 501) and the outside (the space below the cover body 501) at the bottom of the cover body 501.

[0197] The support arm portion 502 will now be described. The support arm portion 502 includes an arm body portion 531, a mounting plate 532 provided at the tip of the arm body portion 531, and two support stays 533 for supporting the arm body portion 531 relative to the cover body portion 501.

[0198] The main body of the arm 531 is made up of a bent rod-shaped member and has a straight horizontal arm portion 531a that extends in the left-right direction and a straight extended arm portion 531b that extends downward from the right side of the horizontal arm portion 531a when viewed from the front, and these arm portions form a roughly L-shaped bend. When viewed from the right side, the extended arm portion 531b is inclined from the top to the bottom and from the front to the rear, that is, in a forward-tilting direction.

[0199] The mounting plate 532 is composed of a plate-shaped member whose left-right direction is the thickness direction and which is sufficiently wider than the width (outer diameter) of the arm body 531. The mounting plate 532 is located to the left of the lower end of the extension arm portion 531b of the arm body 531 and is fixed to the extension arm portion 531b by welding or the like. The mounting plate 532 forms plate-shaped portions that protrude vertically and horizontally from the lower end of the extension arm portion 531b.

[0200] The support stay 533 has a rectangular plate-shaped stay body 534 with the front-to-back direction as the thickness direction and the up-to-down direction as the longitudinal direction, and a nut portion 535 provided on the rear side of the stay body 534. A circular hole 534a is formed through the stay body 534 and communicates with the screw hole of the nut portion 535 (see Figure 29). The support stay 533 is provided at two locations on both ends of the lateral arm portion 531a relative to the arm body 531.

[0201] The support stay 533 is provided with the stay body 534 positioned in front of the lateral arm 531a, and the stay body 534 fixed to the lateral arm 531a by welding or the like. The left support stay 533 has the upper part of the stay body 534 fixed to the lateral arm 531a, and the nut 535 positioned below the lateral arm 531a. The right support stay 533 has the lower part of the stay body 534 fixed to the lateral arm 531a, and the nut 535 positioned above the lateral arm 531a.

[0202] The support arm portion 502, having the configuration described above, is attached to the cover body portion 501 by fixing bolts 536 that engage with each support stay 533. The support arm portion 502 is positioned so that the stay bodies 534 of the left and right support stays 533 are located on the rear side of the lower part of the front cover surface portion 511 of the cover body portion 501, and is fixed to the front cover surface portion 511 by fixing bolts 536.

[0203] The fixing bolt 536 passes through the front cover surface 511 and the stay body 534 and is screwed into the nut 535. For the fixing part by the left support stay 533, the structure of the lower of the two fixing parts that fix the right cover member 505 and the left cover member 506 to each other is shared, and the support stay 533 is fastened to the front cover surface 511 together with the front part 525 of the left cover member 506 by the fixing bolt 536. In other words, for the fixing part by the left support stay 533, the fixing bolt 536 passes through the front cover surface 511, the front part 525 and the stay body 534 and is screwed into the nut 535. A hole 511f is formed on the lower right side of the front cover surface 511 through which the fixing bolt 536 passes (see Figure 27).

[0204] When the support arm portion 502 is fixed to the cover body portion 501, the arm body portion 531 extends to the right from near the lower right corner of the front cover surface portion 511, and the extended arm portion 531b extends diagonally downward and rearward. On the lower right side of the cover body portion 501, an opening 537 is formed as a gap between the lower end of the right side cover surface portion 513 and the lower cover surface portion 514, allowing the arm body portion 531 to extend to the outside of the cover body portion 501 (see Figure 27).

[0205] The mounting structure of the protective cover 500 will now be described. The protective cover 500 is mounted with the right cover member 505 and the left cover member 506 each supported and fixed to the transmission 53, and the support arm portion 502 supported and fixed to the transmission 53. In other words, the protective cover 500 is provided fixed to the transmission 53 by three fixing points: a first fixing point which is the fixing point of the right cover member 505, a second fixing point which is the fixing point of the left cover member 506, and a third fixing point which is the fixing point of the support arm portion 502.

[0206] The first fixing part in the mounting structure of the protective cover 500 will now be described. In the first fixing part, the right cover member 505 is fixedly supported to a support bracket portion 542 provided above the transmission 53 via an L-shaped bracket 538, which is a plate-shaped member bent at a right angle. The L-shaped bracket 538 is provided on the upper cover surface portion 512 of the right cover member 505 so as to form an L shape when viewed from the side.

[0207] The L-shaped bracket 538 has its front fixed surface portion 538a, which is one of the L-shaped surfaces, overlapping the left end of the upper cover surface portion 512 and fixed to the upper cover surface portion 512 by welding or the like. The L-shaped bracket 538 has its fixed surface portion 538a extending rearward from the upper cover surface portion 512, and the other L-shaped surface portion, the support surface portion 538b, rises up from the rear end of the fixed surface portion 538a. The support surface portion 538b is oriented approximately in the front-to-back direction as the thickness direction of the plate. At the left end of the upper cover surface portion 512, a locking surface portion 515 for positioning the L-shaped bracket 538 is bent and formed so as to rise perpendicular to the upper cover surface portion 512.

[0208] The support bracket portion 542, which receives the L-shaped bracket 538 for fixing, is provided in the front upper position approximately midway between the left and right sides of the HST case 313. The support bracket portion 542 has a support surface portion 542a whose thickness is approximately oriented in the front-to-back direction, and left and right side portions 542b that extend forward from both sides of the support surface portion 542a. These surfaces form a roughly U-shape in plan view with the front side open.

[0209] The support bracket portion 542 is provided as part of the shaft support unit 540, which is integrally configured as a mounting member attached to the upper side of the HST case 313 (see Figure 30). The shaft support unit 540 has a tubular shaft support cylinder portion 541 that extends in the left-right direction, a support bracket portion 542 provided on the rear side of the left portion of the shaft support cylinder portion 541, and support leg portions 543 provided on the lower sides of both ends of the shaft support cylinder portion 541.

[0210] The support bracket portion 542 is provided in such a manner that the shaft support cylinder portion 541 is fitted into recesses formed on the front sides of the left and right side portions 542b. The side portions 542b have a roughly triangular shape with the front side as the apex when viewed from the side, and the portion corresponding to the apex is a recess. The shaft support cylinder portion 541 is located in the vertical center relative to the support bracket portion 542, and in a front view, the upper and lower sides of the support bracket portion 542 protrude vertically from the shaft support cylinder portion 541.

[0211] The pivot relay shaft 551 is supported through the shaft support cylinder portion 541. The pivot relay shaft 551 is a component of the power transmission mechanism from the steering case (not shown) to the transmission 53 in the power transmission structure from the steering handle 18 and main shift lever 19 to the transmission 53 via the steering case. The other ends of link plates 552 and 553, one end of which is connected to a connecting member such as a rod that constitutes the power transmission mechanism, are connected to both ends of the pivot relay shaft 551.

[0212] The support leg portion 543 has a support wall portion 543a with the left-right direction as the plate thickness direction and a mounting surface portion 543b with the roughly vertical direction as the plate thickness direction, and these surfaces form a roughly L shape when viewed from the front. The mounting surface portion 543b is bent to the left from the lower end of the support wall portion 543a. In the front-rear direction, the rear part of the mounting surface portion 543b extends backward from the support wall portion 543a as a roughly rectangular plate-shaped portion.

[0213] As shown in Figure 30, the shaft support unit 540 is fixedly supported to the HST case 313 by fixing the left and right support legs 543 to mounting seats 561 provided on both the left and right sides of the upper surface of the HST case 313 with bolts 562. The mounting seats 561 are provided as plate-shaped projections that protrude forward, with their upper surfaces being flat support surfaces 561a. The support surfaces 561a are the surfaces that receive the mounting surfaces 543b of the support legs 543. The mounting seats 561 have two screw holes 561b formed at the front and rear for screwing in the bolts 562. In addition, the rearward extension of the mounting surface 543b has two holes 543c formed at the front and rear for passing the bolts 562 through.

[0214] As shown in Figures 22 and 23, an actuator case 567 is provided on the rear side of the shaft support unit 540 to house and support an actuator 565 (see Figure 23), such as a motor, for operating a link mechanism 570 located on the front side of the transmission 53. The actuator case 567 is configured as a box shape that is flattened in the front-to-back direction, with the front surface being the front support surface 567a. The front support surface 567a is the part that supports the actuator 565 and is a plate-shaped part with the plate thickness direction roughly in the front-to-back direction.

[0215] The actuator case 567 is supported by the shaft support unit 540 in a fixed state via a plurality of vibration-damping members 568. The vibration-damping members 568 are configured in a substantially cylindrical shape including vibration-damping rubber, with male screw portions 568a protruding from both the front and rear sides of the central shaft.

[0216] The vibration-damping members 568 are positioned at a total of three locations: two on the upper and lower sides of the support bracket portion 542, and one on the support stay portion 545 (see Figure 30) which is located to the right of the support bracket portion 542 relative to the shaft support cylinder portion 541. The support stay portion 545 is composed of a bent plate-shaped member that forms a right angle in side view, and forms a mounting surface portion 545a, which is a plate-shaped portion that shares the same position in the front-rear direction as the support surface portion 542a of the support bracket portion 542, at the rear of the shaft support cylinder portion 541.

[0217] As shown in Figure 30, the vibration-damping member 568 is fastened and secured to the support surface portion 542a of the support bracket portion 542 by passing the front male thread portion 568a through the hole 542c and screwing a nut 576 onto the front side of the support surface portion 542a via a washer 575. The vibration-damping member 568 is also fastened and secured to the mounting surface portion 545a of the support stay portion 545 by passing the front male thread portion 568a through the hole 545b and screwing a nut 576 onto the front side of the mounting surface portion 545a via a washer 575. On the other hand, each vibration-damping member 568 is fastened and secured to the front support surface portion 567a of the actuator case 567 by passing the rear male thread portion 568a through the front support surface portion 567a and screwing a nut 577 onto the rear side of the front support surface portion 567a (see Figure 23).

[0218] The link mechanism 570 is part of the configuration for transmitting power from the actuator 565 to the linear operating shaft 375 which protrudes forward from the left end of the HST case 313. The linear operating shaft 375 extends from the travel HST 311. The link mechanism 570 has an operating rod 571 and a link arm 572 which are rotatably connected to each other with the substantially front-rear direction as the pivot axis direction.

[0219] The link arm 572 is composed of an elongated plate-shaped member, with one end connected to the linear operating shaft 375 and the other end connected to one end of the operating rod 571 via a connecting shaft portion 573 whose axial direction is approximately in the front-rear direction. The link arm 572 extends downward from the linear operating shaft 375.

[0220] The operating rod 571 extends diagonally upward and to the right from the connecting shaft portion 573, with its upper end positioned above the upper surface of the HST case 313. At its upper end, the operating rod 571 is connected to the front end of a connecting rod 574, which is oriented axially in the front-rear direction (see Figure 22). The rear end of the connecting rod 574 is located behind the front support surface portion 567a of the actuator case 567 and is connected to the lower end of an operating plate 578, which extends downward from the front support surface portion 567a. The operating plate 578 is designed to perform a predetermined rotational movement using the power of the actuator 565. Based on the operation of the main shift lever 19, etc., the power of the actuator 565 is used to operate the straight-line operating shaft 375 via the link mechanism 570, thereby controlling the straight-line output of the travel HST 311, i.e., the vehicle speed.

[0221] In the configuration described above, the L-shaped bracket 538 provided on the right cover member 505 of the protective cover 500 is fastened and fixed to the support bracket 542 together with the lower of the two vibration-damping members 568, with the support surface portion 538b overlapping the front side of the support surface portion 542a of the support bracket portion 542. That is, the L-shaped bracket 538 passes through the front male thread portion 568a of the lower vibration-damping member 568 through the hole 538c formed in the support surface portion 538b, and is fastened and fixed to the support surface portion 542a by a nut 576 that screws onto the front male thread portion 568a.

[0222] A second fixing part in the mounting structure of the protective cover 500 will now be described. In the second fixing part, the left cover member 506 is fastened together with the sensor bracket 580, which is fixed to the left mounting seat 561 of the HST case 313 together with the left support leg 543 of the shaft support unit 540. The sensor bracket 580 is a support member that supports the angle sensor 581 related to the linear operation shaft 375. The angle sensor 581 is a rotary type potentiometer having a detection arm 581a, and is provided to detect the movement of a member that is linked to the linear operation shaft 375 as the movement of the detection arm 581a.

[0223] The sensor bracket 580 has an upper surface portion 580a, a left side portion 580b, and a front portion 580c, and these surfaces form a semi-box shape. The angle sensor 581 is positioned in front of the front portion 580c of the sensor bracket 580 and is fixed to the front portion 580c at two points by bolts 583. The sensor bracket 580 is fixed to the mounting surface portion 543b of the support leg portion 543 located on the left mounting base portion 561 by bolts 562, with the upper surface portion 580a overlapping the mounting surface portion 543b of the support leg portion 543 located on the left mounting base portion 561. The angle sensor 581 is covered from the front and left side by a sensor cover 584 which is fixed to the front of the front portion 580c of the sensor bracket 580 by screw fastening or the like.

[0224] In this configuration, the protective cover 500 is secured to the left mounting base 561 together with the left support leg 543 and the sensor bracket 580 by bolts 562 at two locations, front and rear, with the upper cover surface 522 of the left cover member 506 overlapping the upper cover surface 522 of the left cover member 506 and the upper surface 580a of the sensor bracket 580. Holes 522a and 580d are formed at two locations, front and rear, in the upper cover surface 522 of the left cover member 506 and the upper surface 580a of the sensor bracket 580, through which the bolts 562 pass.

[0225] A third fixing part in the mounting structure of the protective cover 500 will now be described. In the third fixing part, the support arm 502 is supported by the transmission 53 by fixing the mounting plate 532 to the transmission case 303 with bolts 591.

[0226] The transmission case 303 has a left-right intermediate section, which is the part between the left and right protruding case sections 303a, as a forward-upward projection 303c, and a seat 303e for the mounting plate 532 is provided on the right side surface 303d of the projection 303c. The mating surfaces of the left and right case bodies that make up the transmission case 303 are located in the left-right center of the projection 303c.

[0227] The mounting plate 532 overlaps the seat portion 303e from the right side and is fixed to the right side of the transmission case 303 by three bolts 591. The bolts 591 pass through the mounting plate 532 and are screwed into threaded holes formed in the seat portion 303e. The fixing points by the three bolts 591 are arranged in a roughly front-to-back direction. The mounting plate 532 has three holes 532a formed therein for the bolts 591 to pass through.

[0228] The protective cover 500, attached to the transmission 53 in the configuration described above, primarily covers the upper part of the transmission 53, that is, the upper part of the transmission body 301 and the HST section 302 from the front, and also covers the front end of the upper part of the transmission 53 from the left side, thereby protecting the transmission 53. The protective cover 500 covers the device configuration provided on the front side of the transmission 53 and in its vicinity.

[0229] A link mechanism 570 is provided on the front side of the transmission 53, which includes an operating rod 571 and a link arm 572, which are operating members for operating the transmission mechanism of the transmission 53. The protective cover 500 is provided so as to cover the operating rod 571 and the link arm 572 from the front. In other words, in this embodiment, the link mechanism 570 is provided as a device configuration located on the front side of the transmission 53, and the operating rod 571 and the link arm 572, which are operating members constituting the link mechanism 570, are the members that are covered by the cover body 501 of the protective cover 500.

[0230] As shown in Figure 22, in a front view, the link arm 572 is positioned entirely within the coverage area of ​​the protective cover 500. The link arm 572 is positioned within the coverage area of ​​the left cover member 506 of the protective cover 500. Also in a front view, the operating rod 571 is positioned almost entirely within the coverage area of ​​the protective cover 500, except for its upper end. In a front view, almost the entire portion of the operating rod 571 covered by the protective cover 500 is positioned within the coverage area of ​​the right cover member 505 of the protective cover 500, with its upper end protruding from the upper right corner of the front cover surface 511. The connecting shaft portion 573, which forms the connection between the operating rod 571 and the link arm 572, is positioned within the coverage area of ​​the protective cover 500 in a front view.

[0231] As shown in Figure 23, in the left side view, the operating rod 571, link arm 572, and connecting shaft portion 573 are all located within the coverage area of ​​the cover body portion 501 in approximately the front-rear direction. Also in the left side view, the sensor bracket 580, angle sensor 581, and sensor cover 584 are all located within the coverage area of ​​the cover body portion 501.

[0232] Furthermore, the protective cover 500 is provided with a wire clamp portion 539 for clamping the brake wire 442. One end of the brake wire 442 is supported by a brake wire stay 443 attached to the transmission case 303.

[0233] The brake wire stay 443 is located on the left side of the transmission case 303 and below the transmission input pulley 322, and is secured to the left side of the transmission case 303 by a fixing bolt 441. The fixing bolt 441 is screwed into the transmission case 303 from the left side, passing through the brake wire stay 443 and the brake cover 447.

[0234] The brake wire 442 extends diagonally forward and upward from the left side of the transmission case 303, passes through the left side of the left side cover surface 523 which forms the left side of the protective cover 500, and goes in front of the cover body 501, and is positioned upward toward the driver's compartment 15. In this configuration of brake wire 442 arrangement, the wire clamp portion 539 is provided on the left side cover surface 523 and locks the brake wire 442 to the left side cover surface 523.

[0235] The wire clamp portion 539 is provided by fixing a plate-shaped member having a predetermined bend shape to the left side cover surface portion 523 by welding or the like. The wire clamp portion 539 has a pair of upper and lower clamp pieces 539a that are provided as projections on the left side cover surface portion 523. The wire clamp portion 539 clamps the brake wire 442 to the left side cover surface portion 523 by bending or curving the pair of clamp pieces 539a into a predetermined shape.

[0236] According to the combine harvester 1 of this embodiment, which has the above configuration, in a configuration that includes a transmission 53 located at the front of the traveling body 2, the traveling drive system protection unit 700 is provided, so that the components around the transmission 53 can be protected from foreign objects. In this embodiment, collisions with or intrusion of foreign objects into the device components located on the front side of the transmission 53 can be prevented, and the occurrence of malfunctions in the device components can be suppressed.

[0237] In the combine harvester 1, a protective cover 500 is provided on the front side of the transmission 53. With this configuration, it is possible to prevent foreign objects such as crops to be harvested (harvested produce) or stalk residues from colliding with or entering the transmission case 303 and HST case 313 of the transmission 53, and the front side of the transmission 53 can be protected.

[0238] In particular, during the harvesting of corn, which has thicker stalks than rice or wheat, the harvested crop and its remaining stalks may collide with or enter the front side of the transmission 53, potentially causing malfunctions or other problems in the equipment configurations located on the front side of the transmission 53. Therefore, with a configuration that includes a protective cover 500, the transmission 53 can be protected at least from the front by the protective cover 500, thereby preventing collisions or intrusions of foreign objects into the front side of the transmission 53 and preventing malfunctions in the equipment configurations located on the front side of the transmission 53. Thus, a configuration that includes a protective cover 500 on the front side of the transmission 53 can effectively protect the transmission 53 and the equipment configurations located on the front side of it in a configuration that includes a harvesting unit 3 configured as a cone header, such as the combine harvester 1 according to this embodiment.

[0239] Furthermore, the protective cover 500 has a front cover portion 503 and a side cover portion 504. With this configuration, collisions and intrusions of foreign objects such as corn stalks and residues from the front and sides into the front of the transmission 53 when the machine is moving forward can be effectively suppressed. Specifically, it is possible to prevent foreign objects from entering between the transmission 53 and the front cover portion 503, and to prevent corn stalks and the like guarded by the front cover portion 503 from colliding with or contacting the left side of the transmission 53 as the machine moves forward. Regarding the coverage range of the protective cover 500, the protective cover 500 is provided such that, for example, the height of the upper surface of the cover body portion 501 is at a height of approximately 800 mm or higher from the ground surface, corresponding to the height of corn stalks that are approximately 800 mm from the ground.

[0240] Furthermore, the protective cover 500 is configured to have an opening at the bottom, which is the lower side. With this configuration, the transmission 53 can be protected, and even if foreign matter (impurities) such as harvested crops or stalks enter the inside of the protective cover 500, the foreign matter can be dropped out through the lower opening 530 and discharged, thereby preventing foreign matter from accumulating inside the protective cover 500. This prevents the operation of the device configuration located in front of the transmission 53 from being hindered by foreign matter, and ensures smooth operation. In addition, since it is possible to access the inside of the protective cover 500 through the opening 530, it is possible to perform maintenance on the device configuration covered by the protective cover 500 while the protective cover 500 is installed.

[0241] Furthermore, the device configuration to be covered by the protective cover 500 includes an operating rod 571 and a link arm 572 that constitute the link mechanism 570, located on the front side of the transmission 53. With this configuration, the protective cover 500 can prevent the link mechanism 570 from being struck by foreign objects such as stalks or from foreign objects entering the link mechanism 570, thereby preventing malfunctions or damage to the link mechanism 570.

[0242] In particular, by protecting the link mechanism 570 according to this embodiment with the protective cover 500, malfunctions in vehicle speed control by the HST unit 302 can be prevented. Note that the device configuration to be covered by the protective cover 500, which is provided on the front side of the transmission 53, is not limited to the link mechanism 570. Such configurations include, for example, a link mechanism provided for the sub-transmission mechanism 306, brake arms and wires, wire harnesses connected to sensors provided on the transmission 53, and other mechanisms, various components, and other device configurations that are linked to the power transmission configuration of the transmission 53.

[0243] Furthermore, regarding the support configuration of the protective cover 500, the protective cover 500 has a support arm portion 502 that fixes and supports the cover body portion 501 to the transmission case 303. With this configuration, the protective cover 500 can be directly supported to the transmission case 303, and a simple support configuration can be realized using the existing configuration without having to separately provide a member on the transmission 53 side to support the protective cover 500.

[0244] Similarly, regarding the support configuration of the protective cover 500, in the first fixing part, the right cover member 505 is fixedly supported to a support bracket portion 542 which forms part of the shaft support unit 540 via an L-shaped bracket 538, and in the second fixing part, the left cover member 506 is fixedly supported to a mounting seat portion 561 provided on the HST case 313. With this configuration, regarding the support configuration of the protective cover 500, a simple support configuration can be realized by utilizing the existing configuration without having to separately provide a member on the transmission 53 side to support the protective cover 500.

[0245] In the embodiment described above, the protective cover 500 has a side cover portion 504 that covers the transmission 53 from the left side as a side cover portion according to the present invention. However, it may also have a configuration in which a side cover portion covers the transmission 53 from the right side instead of or in addition to the side cover portion 504. That is, the configuration of the protective cover 500 may be appropriately adopted depending on the configuration of the transmission 53 and the configuration of the devices arranged around the front of the transmission 53, such as having a side cover portion that covers the transmission 53 from one side (left or right) or having two side cover portions that cover the transmission 53 from both sides. Thus, the side cover portion of the protective cover 500 is configured to cover the transmission 53 from at least one side (left or right) of the transmission 53.

[0246] [Third Embodiment] A third embodiment of the present invention will be described with reference to Figures 32 to 42. Similar to the second embodiment, the combine harvester according to this embodiment aims to suppress the occurrence of malfunctions in the device configuration located on the front side of the transmission by providing a protective cover that constitutes a drive system protection unit on the front side of the transmission.

[0247] As shown in Figures 32 and 33, in the transmission 53 according to this embodiment, the transmission case 303 of the transmission body 301 is configured to be vertically elongated, and the HST case 313 of the HST unit 302 is provided on the upper right side of the transmission case 303. The transmission input shaft 52 extends from the upper part of the transmission case 303 toward the left, and the transmission input pulley 322 fixed to the transmission input shaft 52 is positioned on the upper left side of the transmission case 303.

[0248] In this configuration, the combine harvester 1 according to this embodiment includes a drivetrain protection unit 700 that covers and protects the transmission 53. The drivetrain protection unit 700 includes a protective cover 600 provided on the front side of the transmission 53.

[0249] The configuration of the protective cover 600 according to this embodiment will be explained with reference to Figures 32 to 42. In Figure 36, the area covered by the protective cover 600 is indicated by the hatched area. As shown in Figures 32 and 33, the protective cover 600 is provided on the front side of the lower part of the transmission case 303 of the transmission 53.

[0250] The protective cover 600 has its upper end positioned at approximately the same height (slightly above the upper surface 305a) as the upper surface 305a of the chassis base, which is horizontally framed by frame members on the chassis 305. The height of the upper end of the protective cover 600 is approximately the height of the center of the transmission 53 in the vertical direction. The lower end of the protective cover 600 is positioned between the upper surfaces 5c of the tracks 5c of the left and right crawler sections 5 and the left and right axle case sections 303b of the transmission case 303 in the vertical direction. The height of the lower end of the protective cover 600 is approximately the height of the center of the lower half of the transmission 53 in the vertical direction.

[0251] The protective cover 600 has a cover body portion 601 that covers the transmission 53, and left and right support arm portions 602 (602L, 602R) that support the protective cover 500 relative to the transmission 53. That is, the protective cover 600 is a covering member that covers a part of the transmission 53 mainly from the front side with the cover body portion 601, and is provided on the front side of the transmission 53 while being supported by the left and right support arm portions 602. In the protective cover 600 according to this embodiment, the cover body portion 601 corresponds to the front cover portion that covers the transmission 53 from the front.

[0252] The cover body 601 will now be described. The cover body 601 is made up of a substantially rectangular plate-shaped member and is oriented so that the left-right direction is the longitudinal direction when viewed from the front. The cover body 601 has a front surface 611 which is the front plate surface and a back surface 612 which is the rear plate surface.

[0253] The cover main body 601 has a flat plate-shaped portion forming substantially the whole thereof as a main body portion 613. For the main body portion 613, the four corner portions of a substantially rectangular shape are chamfered portions 613a forming inclined sides with respect to the four sides of the rectangular shape. On the upper edge portion and the lower edge portion of the cover main body 601, upper bent surface portions 614 and lower bent surface portions 615 bent at right angles toward the rear side with respect to the main body portion 613 are provided respectively. The upper bent surface portions 614 and the lower bent surface portions 615 have a predetermined width dimension sufficiently small (narrow) with respect to the outer dimension of the main body portion 613, and are formed over the whole of the intermediate portion excluding the left and right chamfered portions 613a with respect to the upper and lower edge portions of the main body portion 613.

[0254] The cover main body 601 has a left-right dimension covering the whole or substantially the whole of the left-right direction of the mission case 303 with respect to the portion within the covering range of the cover main body 601 in the mission case 303 in the up-down direction. That is, in a front view, the portion of the mission case 303 covered by the cover main body 601 in the up-down direction is covered by the cover main body 601 in the whole or substantially the whole of the left-right direction.

[0255] The cover main body 601 is provided in a state inclined in a forward-tilted direction in a side view of the machine body. That is, due to its flat plate-shaped outer shape, the cover main body 601 has a substantially linear outer shape having a width of the plate thickness in a side view, and is provided in a state where the linear outer shape is inclined in a forward-tilted direction (a direction falling forward) with respect to the up-down direction. In other words, in a side view, the cover main body 601 is provided in an inclined state so as to approach from the front side to the rear side (the mission case 303 side) from the upper side to the lower side.

[0256] As shown in FIG. 34, in the present embodiment, the angle θ2 formed by the cover main body 601 in a side view with respect to the up-down direction is an angle of about 10 to 30°, and is about 17° in the illustrated example. However, the inclination angle of the cover main body 601 in a side view is not limited, and the cover main body 601 may be provided along the up-down direction (without inclination) in a side view.

[0257] The left and right support arm portions 602 will be described. The left and right support arm portions 602 are provided so as to be substantially left-right symmetric and have the same basic configuration. Therefore, the left and right support arm portions 602 will be described with the same reference numerals for both of them.

[0258] The left and right support arm portions 602 are provided on the back surface 612 side of the cover main body portion 601 and extend rearward from the cover main body portion 601. In the left-right direction, the left support arm 602L is provided at a position near the left end portion 613b of the cover main body portion 601 (a position that enters inward in the left-right direction from the left end portion 613b), and the right support arm 602R is provided at a position near the right end portion 613c of the cover main body portion 601 (a position that enters inward in the left-right direction from the right end portion 613c).

[0259] The support arm portion 602 has an upper arm portion 621, a lower arm portion 622, and an arm connecting portion 623 that connects these arm portions to each other. The upper arm portion 621 and the lower arm portion 622 are formed of members obtained by bending an elongated rectangular plate-shaped member into a substantially L-shape. The arm connecting portion 623 is formed of an elongated rectangular plate-shaped member.

[0260] One surface portion in the substantially L-shaped bent form of the upper arm portion 621 is a fixed surface portion 621a with respect to the cover main body portion 601, and the other surface portion in the same form is an arm main body portion 621b that extends rearward from the cover main body portion 601. Similarly, one surface portion in the substantially L-shaped bent form of the lower arm portion 622 is a fixed surface portion 622a with respect to the cover main body portion 601, and the other surface portion in the same form is an arm main body portion 622b that extends rearward from the cover main body portion 601. The upper and lower arm main body portions 621b and 622b are both provided such that the left-right direction is the plate thickness direction and their left-right positions are common.

[0261] The arm connecting portion 623 is installed between the upper and lower arm body portions 621b and 622b, with its plate thickness direction oriented horizontally and its longitudinal direction parallel or approximately parallel to the extension direction of the cover body portion 601 in a side view. The longitudinal plate-like member forming the arm connecting portion 623 overlaps the upper and lower arm body portions 621b and 622b from the left and right outer sides and is fixed to the upper and lower arm body portions 621b and 622b by welding or the like. The upper end of the arm connecting portion 623 is fixed to the middle of the longitudinal direction of the upper arm body portion 621b, and the lower end is fixed to the middle of the longitudinal direction of the lower arm body portion 622b.

[0262] Each support arm portion 602 is fixed to the cover body portion 601 by overlapping the fixing surfaces 621a and 622a of the upper arm portion 621a and lower arm portion 622a with the cover body portion 601 from the back surface 612 side, and fixing each fixing surface portion 621a and 622a to the cover body portion 601 with bolts 625. A nut portion 624 with a through-hole is provided on the rear side of each fixing surface portion 621a and 622a. The bolt 625 passes through the cover body portion 601 and the fixing surfaces 621a and 622a from the front side (front surface 611 side) and is screwed into the nut portion 624. The fixing portions of the upper arm portion 621 and lower arm portion 622 by the bolt 625 are located near the four corners of the main body portion 613 of the cover body portion 601. Holes 613d for inserting bolts 625 are formed near the four corners of the main body portion 613 of the cover body portion 601 (see Figure 42).

[0263] The support arm portion 602 is configured to form a roughly H-shape when viewed from the side, with the upper arm portion 621, the lower arm portion 622, and the arm connecting portion 623 (see Figure 40). Therefore, in a side view, a front space portion 620A is formed in front of the arm connecting portion 623, and a rear space portion 620B is formed behind the arm connecting portion 623.

[0264] More specifically, the front space 620A is a space enclosed on all four sides by the cover body 601, the arm connecting portion 623, and the portions of the upper and lower arm body portions 621b and 622b in front of the arm connecting portion 623. The rear space 620B is a space enclosed on three sides by the arm connecting portion 623 and the portions of the upper and lower arm body portions 621b and 622b in rear of the arm connecting portion 623, with the rear side being open.

[0265] In the upper arm portion 621 and the lower arm portion 622, the fixed surface portions 621a and 622a are provided as parts that are bent inward to the left and right relative to the arm body portions 621b and 622b. In other words, the arm body portions 621b and 622b extend to the rearward from the left and right outer sides of the fixed surface portions 621a and 622a. Note that the fixed surface portions 621a and 622a may also be parts that are bent outward to the left and right relative to the arm body portions 621b and 622b.

[0266] Furthermore, the upper and lower arm bodies 621b and 622b are arranged in an inclined shape, mainly due to the downward slope of the upper arm body 621b, so that their tips (rear ends) gradually move closer together from the front (cover body 601 side) to the rear. In addition, the upper arm 621 has a longer extension length from the cover body 601 to the rear compared to the lower arm body 622b. The inclination angle (extension direction) and length of the upper and lower arm bodies 621b and 622b are appropriately changed depending on the position of the fixing parts of the left and right support arm bodies 602 to the transmission case 303.

[0267] The mounting structure of the protective cover 600 will now be described. The protective cover 600 is attached to the transmission 53 in a state where it is fixed to the side of the transmission case 303. Specifically, the protective cover 600 is attached to the transmission 53 in a state where the four arm portions of the left and right support arm portions 602, each consisting of the upper arm portion 621 and the lower arm portion 622, are supported and fixed to the left and right side portions of the upper and lower intermediate portion of the transmission case 303. In other words, the protective cover 600 is provided with the left support arm 602L fixedly supported to the left side of the transmission case 303, and the right support arm 602R fixedly supported to the right side of the transmission case 303.

[0268] The fixing portion of the left support arm 602L will now be described. The left support arm 602L is fastened and fixed to the left side of the transmission case 303 by bolts 631 at the tips of the upper and lower arm bodies 621b and 622b, respectively. Holes 621c and 622c are formed at the tips of the arm bodies 621b and 622b of the left support arm 602L, through which the bolts 631 pass.

[0269] In the transmission case 303, the screw holes for screwing in the bolts 631 are formed in the cover 633, which is part of the transmission case 303. The cover 633 is fixed in multiple places to the left side of the case body, which forms the main body of the transmission case 303, by bolts 632, etc. The cover 633 is a member that closes the opening that opens to the internal space of the transmission case 303 facing the left side, and has a roughly disc-shaped or flattened roughly cylindrical outer shape. In the cover 633, screw holes for screwing in the bolts 631 are formed at two locations, upper and lower, on the periphery, at a position slightly forward of the front-to-back center, with the left side facing the opening. In a left side view, the cover 633 is located directly above the front end of the crawler section 5 (see Figure 34).

[0270] A cover member 640 is provided between the left support arm 602L and the transmission case 303, covering a portion of the transmission case 303. The cover member 640 is fastened to the transmission case 303 together with the left support arm 602L by two bolts 631 that secure the left support arm 602L. The cover member 640 is located on the left and right inner (right side) side of the left support arm 602L.

[0271] The cover member 640 covers the left front corner portion of the upper and lower middle section of the transmission case 303. The cover member 640 is positioned behind the left portion of the cover body 601 and is provided so that, in a front view, the entire cover member 640 is within the coverage area of ​​the protective cover 600. Therefore, in the vertical direction, the upper end of the cover member 640 is located below the upper end of the cover body 601, and the lower end of the cover member 640 is located above the lower end of the cover body 601.

[0272] As shown in Figure 37, the cover member 640 is a member formed by bending a plate-shaped member into a predetermined shape, and has an upper cover surface 641, a left cover surface 642, and a front cover surface 643, and these surfaces form a semi-box shape with the bottom, right side and rear side open.

[0273] The upper cover surface portion 641 is a horizontal plate-like portion with the vertical direction as the plate thickness direction, and forms the upper surface of the cover member 640. The upper cover surface portion 641 has a plate surface shape that is approximately a right triangle, with the right-angle corner of this plate surface shape located on the front left side.

[0274] The left cover surface 642 is a vertical plate-like portion with the left-right direction as the plate thickness direction, and forms the left side surface of the cover member 640. The left cover surface 642 has a roughly rectangular shape with the up-down direction as the longitudinal direction, and together with the upper cover surface 641, it forms a right-angle corner.

[0275] The front cover surface 643 is a vertical plate-like portion with the front-to-back direction as the plate thickness direction, and forms the front surface of the cover member 640. The front cover surface 643 has a substantially rectangular shape with the vertical direction as the longitudinal direction, and together with the upper cover surface 641 and the left cover surface 642, it forms right-angle corners. The front cover surface 643 has the same or substantially the same dimensions as the left cover surface 642 in the vertical direction, and the dimensions in the shorter direction (left-to-right direction) of the rectangular shape are smaller than the same dimensions (dimensions in the front-to-back direction) of the left cover surface 642.

[0276] The cover member 640 is fixed to the lid 633 by bolts 631, with the left cover surface 642 overlapping the upper and lower arm body portions 621b and 622b of the left support arm 602L from the inside (right side), and the left cover surface 642 interposed between the upper and lower arm body portions 621b and 622b and the lid 633. Two holes 642a are formed near the rear edge of the left cover surface 642, one above the other, through which the bolts 631 pass (see Figure 37).

[0277] The cover member 640, with its left cover surface portion 642, completely covers the rear space 620B of the left support arm 602L, while also covering a portion of the front space 620A (see Figure 34). Furthermore, in the front-rear direction, the rear end of the cover member 640 is positioned approximately the same as the rear ends of the upper and lower arm bodies 621b and 622b of the left support arm 602L, and in a left side view, it covers the front of the lid 633 from the left.

[0278] In the vertical direction, the cover member 640 has its upper cover surface 641 positioned at approximately the same height as the upper edge of the upper arm body 621b of the left support arm 602L. In the vertical direction, the lower end of the cover member 640 is positioned at the height between the upper and lower ends of the lower arm body 622b of the left support arm 602L.

[0279] The cover member 640 is provided such that the front cover surface portion 643 is positioned in front of the lid body 633 and the entire lid body 633 is positioned within the coverage range of the front cover surface portion 643 in a front view. The front cover surface portion 643 is a vertical surface portion along the vertical direction and is positioned behind the cover main body portion 601 having a forward tilt. Therefore, the size of the front-rear direction interval between the front cover surface portion 643 and the cover main body portion 601 gradually decreases (narrows) from the upper side to the lower side according to the inclination of the cover main body portion 601.

[0280] In the cover structure provided with the cover member 640 between the left support arm 602L and the transmission case 303 as described above, the left cover surface portion 642 of the cover member 640 functions as a side cover portion that covers the transmission 53 from the left side, which is one side in the left-right direction, together with the left support arm 602L. Further, the front cover surface portion 643 of the cover member 640 functions as a front cover portion that covers the transmission 53 from the front together with the cover main body portion 601.

[0281] The fixing portion of the right support arm 602R will be described. As shown in FIGS. 35 and 36, the right support arm 602R fastens and fixes the tip portions of the upper and lower arm main body portions 621b and 622b to the side surface portion on the right side of the transmission case 303 by bolt members 636, respectively. Hole portions 621d and 622d through which the bolt members 636 pass are formed at the tip portions of the arm main body portions 621b and 622b of the right support arm 602R, respectively. In the transmission case 303, screw holes for screwing the bolt members 636 are formed at two locations in the vertical direction near the front end portion of the upper and lower intermediate portions in the right case body forming the main body portion of the transmission case 303, with the right side as the opening side.

[0282] The bolt member 636 has a head and a rod-shaped screw shaft portion 636a having a threaded portion. A nut 637 (see Figure 36) is screwed onto the threaded portion of the screw shaft portion 636a, and the arm body portions 621b and 622b of the right support arm 602R are fastened and fixed to the transmission case 303 by the nut 637. The bolt member 636 has the screw shaft portion 636a extending to the right from the fixing portion by the nut 637 screwed onto the screw shaft portion 636a.

[0283] One (lower) hook portion 651a of a biasing spring 651, which is a coil spring, is locked to the threaded shaft portion 636a of the lower bolt member 636. The other (upper) hook portion 651b of the biasing spring 651 is locked to the middle of a straight brake arm 652, which is made up of an elongated plate-shaped member. The brake arm 652 is an operating arm for operating the brake, which is provided on the brake shaft that constitutes the sub-transmission mechanism 306 (see Figure 7). The brake is covered by a brake cover 653, and the brake arm 652 is provided on the right side of the brake cover 653.

[0284] The brake arm 652 is positioned with its longitudinal direction approximately in the front-rear direction, and is supported at its rear end by a pivot support 652a so as to be rotatable in the axial direction, extending forward from the pivot support 652a. At its front end, the brake arm 652 is engaged with a hook portion 654a provided at the lower end of a brake spring 654. One end of a brake wire 655 is connected to the other end (upper side) of the brake spring 654.

[0285] The other end of the brake wire 655 is connected to a predetermined operating member for brake operation provided in the driver unit 15. By operating the operating member, the brake arm 652 is rotated, the brake is activated, restricting the rotation of the brake shaft of the auxiliary transmission mechanism 306, and braking the transmission of power to the drive sprocket 5a.

[0286] The brake wire 655 extends upward from the right side of the upper and lower middle section of the transmission case 303, passing through the front of the transmission 53 and being routed toward the driver's compartment 15. A brake wire stay 656 is provided on the upper front side of the transmission 53 to support the brake wire 655. The brake wire stay 656 has a plate-shaped support projection 656a that protrudes forward as the part that supports the brake wire 655, and the brake wire 655 is fixedly supported by passing the brake wire 655 through the support projection 656a.

[0287] The protective cover 600, attached to the transmission 53 in the configuration described above, protects the transmission 53 by covering the upper and lower middle section of the transmission 53 from the front. The protective cover 600 covers the device configuration located on the front side of the transmission 53 or in its vicinity.

[0288] A sub-transmission link arm 660, which is an operating member for operating the transmission mechanism of the transmission 53, is provided on the front side of the transmission 53. The protective cover 600 is provided so as to cover the sub-transmission link arm 660 from the front. In other words, in this embodiment, the sub-transmission link arm 660 is provided as a device configuration located on the front side of the transmission 53, and the sub-transmission link arm 660 and the members connected to the sub-transmission link arm 660 are the members that are covered by the cover body portion 601 of the protective cover 600.

[0289] The sub-transmission link arm 660 is a component for operating the gear shifter that constitutes the sub-transmission mechanism 306 (see Figure 7), and is composed of a roughly rectangular plate-shaped elongated member. The gear shifter is a component for performing gear switching operations in the sub-transmission mechanism 306.

[0290] The sub-transmission link arm 660 is provided with its longitudinal direction oriented laterally and is supported at a pivot point 661 located at one end (left side) so as to be rotatable in the axial direction, with its longitudinal direction being axial, and extends to the right from the pivot point 661. The pivot point 661 is located near the joint between the left and right case bodies that constitute the transmission case 303 in the left-right direction and is provided on the right case body.

[0291] The auxiliary transmission link arm 660 is linked to the auxiliary transmission lever provided in the driver's unit 15 by an interlocking mechanism including a connecting rod 662. The connecting rod 662 has one end (lower end) connected to the other end (right side) of the auxiliary transmission link arm 660 and extends upward from the auxiliary transmission link arm 660 on the front side of the transmission 53. By operating the auxiliary transmission lever, the gear shifter of the auxiliary transmission mechanism 306 is operated via the auxiliary transmission link arm 660, allowing for switching between high, medium, and low speeds.

[0292] As shown in Figure 36, in a front view, the auxiliary transmission link arm 660 is positioned entirely within the coverage area of ​​the protective cover 600. In a front view, the auxiliary transmission link arm 660 is located in the upper part of the coverage area of ​​the protective cover 600, slightly to the right of the left-right middle section. Also in a front view, the lower end of the connecting rod 662 connected to the right end of the auxiliary transmission link arm 660 is located within the coverage area of ​​the protective cover 600.

[0293] Furthermore, the protective cover 600 is configured to have an open side at the bottom. The protective cover 600 has a flat plate-shaped cover body 601 that is provided in a forward-sloping manner, and left and right support arm portions 602 that extend rearward from positions near the left and right edges of the cover body 601. The cover body 601 is positioned in front of the transmission case 303 with a gap between them, and a part of the front of the transmission case 303 is sandwiched between the left and right support arm portions 602.

[0294] With this configuration of the protective cover 600, there is an opening 670 on the lower side of the protective cover 600, which is the gap between the cover body 601 and the transmission case 303 (see Figures 34 and 35). The opening 670, located below the forward-sloping cover body 601, connects the space enclosed by the cover body 601 and the left and right support arm portions 602 at the front of the transmission case 303 with the outside (the space below the protective cover 600).

[0295] Furthermore, in the configuration in which the cover body 601 is positioned in a forward-leaning shape, an open portion 671 exists above the protective cover 600, between the cover body 601 and the transmission case 303, with a gap wider than the lower opening 670. The open portion 671 above the cover body 601 opens the space enclosed by the cover body 601 and the left and right support arm portions 602 at the front of the transmission case 303 to the outside (the space above the protective cover 600).

[0296] According to the combine harvester 1 of this embodiment, which has the above configuration, similar to the second embodiment, in a configuration that includes a transmission 53 located at the front of the traveling body 2, it is possible to prevent foreign objects from colliding with or entering the device configuration located on the front side of the transmission 53, and to suppress the occurrence of malfunctions in the device configuration.

[0297] In the combine harvester 1, a protective cover 600 is provided on the front side of the transmission 53. With this configuration, it is possible to prevent foreign objects such as crops to be harvested (harvested produce) or stalk residues from colliding with or entering the transmission case 303 of the transmission 53, and the front side of the transmission 53 can be protected.

[0298] In this embodiment, the cover body 601 of the protective cover 600 is made of a flat plate-shaped member. However, the configuration of the cover body 601 is not limited as long as it can prevent foreign objects such as crops and stalks from colliding with or entering the transmission 53.

[0299] Figure 42 shows a modified example of the cover body 601. In the example shown in Figure 42, the cover body 601 has a rectangular plate-like outer shape with the left-right direction as its longitudinal direction, and most of it, excluding the peripheral edge, is a mesh portion 682. The cover body 601 has an outer frame portion 681 that follows its rectangular outer shape, and a mesh portion 682 that is provided over the entire rectangular area inside the outer frame portion 681.

[0300] In the example shown in Figure 42, the outer frame portion 681 is a rectangular frame-shaped portion formed by four edges: a pair of longitudinal edges 681a of a predetermined width along the longitudinal side of the rectangular outer shape of the cover body portion 601, and a pair of longitudinal edges 681b of a predetermined width along the transverse side of the same outer shape.

[0301] The mesh section 682 is a grid-like section formed by a number of vertical bars 682a and a number of horizontal bars 682b. The vertical bars 682a are straight rod-shaped sections installed between the upper and lower longitudinal sides 681a along the shorter direction (up and down direction in a front view) of the cover body 601. The horizontal bars 682b are straight rod-shaped sections installed between the left and right short sides 681b along the longitudinal direction (left and right direction) of the cover body 601. The number of vertical bars 682a and the number of horizontal bars 682b are arranged at equal intervals at predetermined intervals.

[0302] As shown in this modified example, the cover body 601 may be configured in a grid or mesh pattern, either entirely or partially. In addition, the cover body 601 may have multiple through-holes, such as those made of perforated metal (porous plate). By configuring the cover body 601 to have through-holes such as a mesh section 682 or a group of holes, the weight of the protective cover 600 can be reduced, and the openings allow for ventilation, thus ensuring heat dissipation of the transmission 53.

[0303] In particular, as shown in the example configuration in Figure 42, a configuration in which the cover body 601 has a mesh portion 682 that makes up the majority of the cover body can effectively reduce the weight of the protective cover 600 and provide good ventilation to ensure heat dissipation of the transmission 53.

[0304] Furthermore, the protective cover 600 has a cover member 640 having a left cover surface portion 642, etc. With this configuration, collisions and intrusions of foreign objects such as stalks and debris from the front and sides into the front of the transmission 53 when the machine is moving forward can be effectively suppressed. Specifically, it is possible to prevent foreign objects from entering between the transmission 53 and the cover body portion 601, and to prevent stalks and debris guarded by the cover body portion 601 from colliding with or contacting the left side of the transmission 53 as the machine moves forward.

[0305] Furthermore, the protective cover 600 is configured to have an opening at the bottom, which opens downwards. With this configuration, the transmission 53 can be protected, and even if foreign matter (impurities) such as harvested crops or stalks enter the inside of the protective cover 600, the foreign matter can be dropped out through the opening at the bottom 670 and discharged, thereby preventing foreign matter from accumulating inside the protective cover 600. This prevents the operation of the device configuration located in front of the transmission 53 from being hindered by foreign matter, and ensures smooth operation.

[0306] Furthermore, the protective cover 600 is configured to have an open section 671 on its upper side between it and the transmission 53. With this configuration, it is possible to access the inside of the protective cover 600 from the upper side through the open section 671, so that maintenance can be performed on the device components covered by the protective cover 600, such as the sub-transmission link arm 660, while the protective cover 600 is installed.

[0307] Furthermore, as a device component to be covered by the protective cover 600, a sub-transmission link arm 660 is provided on the front side of the transmission 53. With this configuration, the protective cover 600 can prevent the sub-transmission link arm 660 and its connecting part from being struck by foreign objects such as stalks, and prevent foreign objects from entering between the sub-transmission link arm 660 and the transmission case 303, thereby preventing malfunctions such as failure or damage to the sub-transmission link arm 660.

[0308] In particular, by protecting the sub-transmission link arm 660 according to this embodiment with the protective cover 600, it is possible to prevent malfunctions in the sub-transmission operation using the sub-transmission lever. Note that the device configuration to be covered by the protective cover 600, which is provided on the front side of the transmission 53, is not limited to the sub-transmission link arm 660, as in the first embodiment.

[0309] Furthermore, in the protective cover 600, the cover body 601 is provided in an inclined shape that tilts forward. With this configuration, foreign objects such as crops and stalks that come into contact with or collide with the cover body 601 from the front can be deflected downwards. As a result, compared to a configuration in which the cover body 601 is provided vertically (perpendicular to the front-to-back direction of the machine), the impact received by the cover body 601 from foreign objects at the front can be reduced, and from the viewpoint of ensuring the strength (impact resistance) of the cover body 601, it becomes possible to make the cover body 601 a relatively lightweight and simple structure.

[0310] Furthermore, regarding the support configuration of the protective cover 600, the protective cover 600 is attached to the transmission 53 while being fixed to the side of the transmission case 303. With this configuration, the protective cover 600 can be directly supported by the transmission case 303, and a simple support configuration can be realized using the existing configuration without having to provide a separate member on the transmission 53 side to support the protective cover 600.

[0311] In particular, in this embodiment, the protective cover 600 has left and right support arm portions 602 that securely support the cover body portion 601 by sandwiching the transmission case 303 from both sides. With this configuration, it is possible to firmly fix and support the protective cover 600 to the transmission 53 with a simple support structure by utilizing the shape of the front part of the transmission case 303.

[0312] [Fourth Embodiment] A fourth embodiment of the present invention will now be described. The combine harvester 1 according to this embodiment includes a cover unit 800 as a drive system protection part that covers the transmission 53 and drive belt 323 from at least one side.

[0313] The configuration of the cover unit 800 will be explained using Figures 44 to 51. Figure 50 is a cross-sectional view of position XX in Figure 45. As shown in Figures 44 to 51, the cover unit 800 is generally configured to cover an area that is the sum of the covering area by the protective cover 401 according to the first embodiment and the covering area by the protective cover 500 according to the second embodiment.

[0314] The cover unit 800 has a side cover portion 801 as a first cover portion that covers the drive belt 323 from the left side, which is one of the left and right sides; a front cover portion 802 as a second cover portion that covers the transmission 53 from the front; and an intermediate cover portion 803 as a third cover portion provided between the side cover portion 801 and the front cover portion 802.

[0315] The cover unit 800 has a predetermined curved shape in plan view, formed by a side cover portion 801, a front cover portion 802, and an intermediate cover portion 803, and is configured to cover the transmission 53 from the front and the drive belt 323 from the front and left side. The cover unit 800 has open sides on both the top and bottom, and forms a continuous wall-like cover portion from the front of the upper part of the transmission 53 to the left side of the first belt transmission mechanism 51.

[0316] The cover unit 800 is composed of a left cover member 806 that constitutes a lateral cover portion 801, a front cover member 807 that constitutes a front cover portion 802, and an intermediate cover member 808 that mainly constitutes an intermediate cover portion 803. The left cover member 806 and the front cover member 807 are fixed to the intermediate cover member 808, respectively. These three cover members are members formed by bending a plate-shaped member into a predetermined shape.

[0317] The side cover portion 801 will now be described. The coverage area of ​​the side cover portion 801 is substantially the same as that of the side cover portion 411 according to the first embodiment. The side cover portion 801 is a substantially rectangular surface portion with the left-right direction as the plate thickness direction and the front-rear direction as the longitudinal direction, and is located to the left of the first belt transmission mechanism 51 including the drive belt 323.

[0318] As shown in Figure 46, the side cover portion 801 has its front edge portion 801a positioned approximately at the same location as the front end of the transmission input pulley 322 in the front-rear direction. The side cover portion 801 has its rear edge portion 801b positioned in front of the engine output pulley 321 and near the front end of the engine output pulley 321. Both the front edge portion 801a and the rear edge portion 801b of the side cover portion 801 are vertical edges that align in the vertical direction.

[0319] As shown in Figure 46, the lower edge 801c of the side cover portion 801 is positioned at approximately the same height as the lower end of the transmission input pulley 322 in the vertical direction. Therefore, in a side view, the lower edge 801c of the side cover portion 801 is provided so as to follow (approximately coincide with) the lower path portion 323a, which is the front-to-back extending path portion of the drive belt 323 between the lower ends of the engine output pulley 321 and the transmission input pulley 322, respectively. The lower edge 801c of the side cover portion 801 has a narrow lower bent surface portion 801f formed over approximately the entire length in the front-to-back direction, which is bent at a right angle inward (to the right) relative to the main body portion of the side cover portion 801 (see Figure 49).

[0320] Furthermore, as shown in Figure 46, the upper edge 801d of the side cover portion 801 is positioned at approximately the same height as the upper end of the transmission input pulley 322 in the vertical direction. The upper edge 801d of the side cover portion 801 has an upper bent surface portion 801e formed over approximately the entire length in the front-rear direction, which is a narrow portion that is bent at a right angle inward (to the right) relative to the main body portion of the side cover portion 801. The lower edge 801c and upper edge 801d of the side cover portion 801 are both horizontal edges that are aligned in the front-rear direction.

[0321] The lateral cover portion 801 described above covers, from the left, substantially the entire portion of the drive belt 323, excluding the portion wound around the engine output pulley 321 and the portion near its front.

[0322] The front cover portion 802 will now be described. The coverage area of ​​the front cover portion 802 is substantially the same as that of the front cover portion 503 according to the second embodiment. The front cover portion 802 has a front cover surface portion 811, an upper cover surface portion 812, a right side cover surface portion 813, and a downward inclined surface portion 814.

[0323] The front cover surface 811 is a roughly rectangular surface with the front-to-back direction as the thickness direction and the up-to-down direction as the longitudinal direction, and is located in front of the upper part of the transmission 53. The front cover surface 811 has a protruding surface 811a on the upper right half that protrudes upward relative to the left side. The front cover surface 811 constitutes the majority of the front cover portion 802.

[0324] The front cover surface 811 has its upper end, protruding portion 811a, positioned at approximately the same height as the upper surface of the HST case 313 of the HST section 302, which forms the upper surface of the transmission 53, in the vertical direction. The lower end of the front cover surface 811 is positioned approximately in the center of the transmission 53 in the vertical direction.

[0325] The front cover surface 811 is provided so as to cover substantially the entire area between the left and right protruding case portions 303a of the transmission 53 in the left-right direction. In the front-rear direction, the front cover surface 811 is located in front of the transmission input pulley 322. In the portion to the left of the protruding surface 811a, the height of the upper edge of the front cover surface 811 is substantially the same as the height of the upper edge 801d of the side cover portion 801, and the height of the lower edge is located below the height of the lower edge 801c of the side cover portion 801.

[0326] The upper cover surface portion 812 is a substantially rectangular plate-shaped portion with the vertical direction as the plate thickness direction and the horizontal direction as the longitudinal direction. The upper cover surface portion 812 extends rearward from the entire upper edge of the protruding surface portion 811a of the front cover surface portion 811, forming a right-angle corner with the front cover surface portion 811.

[0327] The right-side cover surface 813 is a roughly rectangular plate-shaped portion with the left-right direction as the plate thickness direction and the up-down direction as the longitudinal direction. The right-side cover surface 813 extends rearward from the right edge of the front cover surface 811, forming a right-angle corner with the front cover surface 811 and the upper cover surface 812. The width dimension (dimension in the front-to-back direction) of the right-side cover surface 813 is smaller than the left-to-right dimension of the front cover surface 811 (approximately 1 / 8).

[0328] The downward inclined surface portion 814 is a surface portion provided on the lower side of the front cover surface portion 811, and is a downward-sloping inclined surface portion that is bent in an obtuse angle together with the front cover surface portion 811 from the entire lower edge of the front cover surface portion 811 toward the rear. The downward inclined surface portion 814 has a dimension of about 1 / 10 of the front cover surface portion 811 in the vertical direction.

[0329] The intermediate cover portion 803 will now be described. The intermediate cover portion 803 has a covering range in a front view that includes the covering range of the front cover portion 412 according to the first embodiment and the covering range of the front inclined cover surface portion 521 according to the second embodiment. The intermediate cover portion 803 has a front inclined cover surface portion 821 and a downward inclined cover surface portion 822.

[0330] The front-sloping cover surface portion 821 is a surface portion that is inclined with respect to the front-rear direction in a plan view, with its outer surface facing diagonally forward to the left, and has a substantially trapezoidal shape. In detail, the front-sloping cover surface portion 821 has a substantially trapezoidal shape when laid on its side, with the rear side as the upper base and the front side as the lower base. In this embodiment, the angle that the front-sloping cover surface portion 821 makes with respect to the front-rear direction in a plan view is approximately 45°.

[0331] The downward-sloping cover surface portion 822 is bent at an obtuse angle together with the forward-sloping cover surface portion 821, extending inward from the lower edge of the forward-sloping cover surface portion 821 towards the inside of the cover unit 800. Together with the forward-sloping cover surface portion 821, the downward-sloping cover surface portion 822 forms a straight ridge portion 822a. The ridge portion 822a is inclined downward in the front direction when viewed from the left side and downward in the right direction when viewed from the front. The downward-sloping cover surface portion 822 has a roughly inverted trapezoidal projection shape that gradually narrows in width from the top to the bottom.

[0332] In the intermediate cover portion 803, an upper bent surface portion 823, which is a narrow portion that is bent perpendicularly inward from the front inclined cover surface portion 821, is formed over substantially the entire upper edge of the front inclined cover surface portion 821. In addition, a corner surface portion 824 is provided on the rear side of the upper part of the lower inclined cover surface portion 822, in which the front end of the lateral cover portion 801 is extended downward in a projection-like manner. The corner surface portion 824 is provided to fill the gap between the upper part of the lower inclined cover surface portion 822 and the front end of the lateral cover portion 801.

[0333] The intermediate cover portion 803 is positioned in front of the drive belt 323 by its forward-sloping cover surface portion 821, and covers the entire portion of the drive belt 323 that is wound around the transmission input pulley 322 from the front. The intermediate cover portion 803 also covers the support portion of the brake wire 442 for the brake wire stay 443 from the left front side by its downward-sloping cover surface portion 822.

[0334] The fixing structure between the left cover member 806, the front cover member 807, and the intermediate cover member 808 that constitute the cover unit 800 having the above configuration is as follows.

[0335] The intermediate cover member 808 has a rear fixing surface portion 808a as its rear edge, which is a fixing surface portion to the left cover member 806. The rear fixing surface portion 808a is a surface portion that is bent at a predetermined width at an obtuse angle relative to the main body portion of the intermediate cover member 808 that forms the intermediate cover portion 803, so as to conform to the plate surface shape of the lateral cover portion 801. The upper edge of the rear fixing surface portion 808a is bent and formed to conform to the front end portion of the upper bent surface portion 801e.

[0336] The intermediate cover member 808 is fixed to the left cover member 806 at two points, top and bottom, by fixing bolts 831, with the rear fixing surface portion 808a overlapping the front end of the left cover member 806 from the outside (left side). The fixing bolts 831 pass through the rear fixing surface portion 808a and the left cover member 806 and are screwed into nut portions 832 provided on the inside (right side) of the left cover member 806.

[0337] The intermediate cover member 808 has a front fixing surface portion 808b as its front edge, which is a fixing surface portion to the front cover member 807. The front fixing surface portion 808b is a surface portion that is bent at a predetermined width at an obtuse angle relative to the main body portion of the intermediate cover member 808 that forms the intermediate cover portion 803, so as to conform to the plate surface shape of the front cover portion 802. An upper bent surface portion 808c is formed on the upper edge of the front fixing surface portion 808b, which is a narrow portion that is bent at a right angle toward the rear.

[0338] The intermediate cover member 808 is fixed to the front cover member 807 at two points, top and bottom, by fixing bolts 833, with the front fixing surface portion 808b overlapping the left end of the front cover member 807 from the outside (front side). The fixing bolts 833 pass through the front fixing surface portion 808b and the front cover member 807 and are screwed into nuts 834 provided on the inside (rear side) of the front cover member 807.

[0339] The cover unit 800 is configured to have the upper side of the drive belt 323 open. That is, in a plan view, the cover unit 800 is provided so as to expose the entire drive belt 323 of the first belt transmission mechanism 51 that extends in the front-rear direction.

[0340] The mounting structure of the cover unit 800 will now be described. The cover unit 800 is mounted with the left cover member 806 fixedly supported to the chassis 305 of the running machine 2, and the front cover member 807 fixedly supported at two points to the configuration on the transmission 53 side. The cover unit 800 is provided fixed to the chassis 305 and the transmission 53 by three fixing points: the first fixing point which is the fixing point of the left cover member 806, and the second and third fixing points which are the fixing points of the front cover member 807.

[0341] The first fixing part in the mounting structure of the cover unit 800 will now be described. In the first fixing part, the cover unit 800 is supported and fixed to the support plate 850 of the horizontal plate, which is a component of the chassis 305, via support stays 841 provided at two locations, front and rear, on the left cover member 806. The support plate 850 is a perforated plate having a rectangular outer shape and is provided in a state supported by the components of the chassis 305 and the transmission case 303.

[0342] Specifically, the left side of the support plate 850 is fixed to the vertical frame 851 that constitutes the chassis 305, either directly or indirectly via other components, by welding or the like. The vertical frame 851 is composed of rectangular pipe-shaped members that extend in the front-rear direction and extends across the entire front-rear direction of the chassis 305. The vertical frame 851 is located to the left of the cover unit 800 in the left-right direction.

[0343] The rear side of the support plate 850 is fixedly supported by a connecting plate 852 to a support base portion 452 provided on a pipe-shaped member 451 that constitutes the chassis 305 (see Figure 46). The connecting plate 852 is fixed to the support plate 850 and the support surface portion 452a of the support base portion 452 by welding or the like.

[0344] The right side of the support plate 850 is fixedly supported by the transmission case 303 at two points, front and rear, via support brackets (853, 854) (see Figures 46 and 48). The support brackets (853, 854) are bent plate-shaped members, each having a first horizontal surface that overlaps the support plate 850 and is fixed to the support plate 850, and a second vertical surface with the left-right direction as the thickness direction and is fixed to the transmission case 303 side.

[0345] As shown in Figures 46 and 48, the first support bracket 853, provided at the right front corner of the support plate 850, has its first surface overlapping the support plate 850 from above and is fixed to the support plate 850 by a bolt 855. The bolt 855 passes through the first surface of the first support bracket 853 and the support plate 850 and is screwed into a nut portion 856 provided on the underside of the support plate 850. The second surface of the first support bracket 853 overlaps the left open end face of the first boss portion 861, which is a cylindrical screw hole forming portion projecting to the left in the transmission case 303, and is fixed to the first boss portion 861 by a bolt 862. The bolt 862 passes through the second surface of the first support bracket 853 and is screwed into the screw hole of the first boss portion 861.

[0346] The second support bracket 854, located in the front-to-rear intermediate section on the right side of the support plate 850, has its first surface overlapping the support plate 850 from below and is fixed to the support plate 850 by bolts 857. The bolts 857 pass through the first surface of both the support plate 850 and the second support bracket 854 and are screwed into nuts 858 located on the underside of the first surface. The second support bracket 854 has its second surface overlapping the left open end face of the second boss portion 863, which is provided in the transmission case 303 in the same way as the first boss portion 861, and is fixed to the second boss portion 863 by bolts 864.

[0347] The support stay 841 is a rectangular plate-shaped member with its longitudinal direction in the vertical direction and its thickness direction in the horizontal direction. It is fixed to the side cover portion 801 and extends downward from the lower edge portion 801c of the side cover portion 801, with its lower end fixed to the left end of the support plate 850. The support stay 841 has a bent surface portion 841a at its lower end that is bent toward the right, forming a right-angle corner with the main body portion of the support stay 841. The support stay 841 is fixed to the support plate 850 by welding or the like, with the bent surface portion 841a overlapping the support plate 850 from above.

[0348] The support stay 841 is located on the inside (right side) of the side cover portion 801 and is fixed by a bolt 865. The bolt 865 passes through the side cover portion 801 and the support stay 841 from the left side and is screwed into a nut portion 866 provided on the right side of the support stay 841 (see Figure 48). Each support stay 841 has two fixing points by the bolt 865, one at the top and one at the bottom. A notch is formed in the lower bent surface portion 801f of the side cover portion 801 to avoid interference with the front and rear support stays 841.

[0349] Of the two support stays 841, the front support stay 841 is located approximately in the center of the side cover portion 801 in the front-rear direction, and the rear support stay 841 is located near the rear end of the side cover portion 801.

[0350] A second fixing part in the mounting structure of the cover unit 800 will now be described. In the second fixing part, the cover unit 800 is fixedly supported to the transmission case 303 via a support arm portion 870 provided on the rear side of the front cover member 807.

[0351] The support arm portion 870 is provided on the back surface 811b side of the front cover surface portion 811 of the front cover member 807 and extends rearward from the front cover surface portion 811. The support arm portion 870 has a support arm main body portion 871 and a reinforcing plate portion 872 that reinforces the support arm main body portion 871.

[0352] The support arm body portion 871 is composed of a member formed by bending a long, narrow rectangular plate-like member into a roughly L-shape. In the roughly L-shaped bent form of the support arm body portion 871, one surface portion is fixed to the front cover surface portion 811, and the other surface portion in the same form is an arm portion 871b that extends to the rear from the front cover surface portion 811.

[0353] The member forming the support arm body portion 871 has its fixed surface portion 871a fixed to the back surface portion 811b of the front cover surface portion 811 by welding or the like. The support arm body portion 871 is provided so that the thickness direction of the arm portion 871b is in the left-right direction.

[0354] The reinforcing plate portion 872 is composed of a flat, elongated plate-like member. The reinforcing plate portion 872 is positioned below the support arm body portion 871, with its vertical direction being the thickness direction and its longitudinal direction inclined with respect to the front-rear direction in a plan view, and is installed between the fixed surface portion 871a and the arm portion 871b. The member forming the reinforcing plate portion 872 is fixed at one end in the longitudinal direction to the fixed surface portion 871a and at the other end to the arm portion 871b by welding or the like.

[0355] The support arm portion 870 is fastened and fixed to the protruding portion 303f, which is formed to protrude in a step-like manner on the front side of the upper part of the transmission case 303, by bolts 875 and nuts 876. The tip of the support arm portion 870 is overlapped from the right side with the right-side open end face of the boss portion 303g, which is formed to have a protrusion to the right on the protruding portion 303f, and bolts 875 are passed through the tip of the arm portion 871b.

[0356] Bolt 875 is one of several bolts that secure the left and right case bodies of the transmission case 303 together. It passes through the boss portion 303g and the arm portion 871b from the left, and is screwed into the nut 876 at the portion that protrudes to the right from the arm portion 871b. The part secured by bolt 875 is located within the coverage area of ​​the front cover portion 802 when viewed from the front.

[0357] A third fixing part in the mounting structure of the cover unit 800 will now be described. In the third fixing part, the cover unit 800 is fixedly supported to the configuration on the transmission 53 side via an L-shaped bracket 881 provided on the upper side of the front cover member 807. The L-shaped bracket 881 is provided on the upper cover surface 812 of the front cover member 807 so as to form an L shape when viewed from the side.

[0358] The L-shaped bracket 881 has one L-shaped surface, the fixed surface 881a, with its front end overlapping the left end of the upper cover surface 812, and is fixed to the upper cover surface 812 by welding or the like. The fixed surface 881a of the L-shaped bracket 881 extends rearward from the upper cover surface 812, and the other L-shaped surface, the support surface 881b, rises from the rear end of the fixed surface 881a. The support surface 881b is oriented approximately in the front-to-back direction as the thickness direction of the plate. At the left end of the upper cover surface 812, a locking surface 815 for positioning the L-shaped bracket 881 is bent and formed so as to rise perpendicular to the upper cover surface 812.

[0359] The L-shaped bracket 881 is provided with a reinforcing plate portion 882, which is made up of a flat, elongated plate-like member. The reinforcing plate portion 882 is located to the right of the L-shaped bracket 881, with the left-right direction being the thickness direction and the longitudinal direction inclined with respect to the front-back direction in a side view, and is installed between the fixing surface portion 881a and the support surface portion 881b. The member forming the reinforcing plate portion 882 is fixed at one end in the longitudinal direction to the fixing surface portion 881a and at the other end to the support surface portion 881b by welding or the like.

[0360] The L-shaped bracket 881 is fixed to a support bracket portion 542 which forms part of the shaft support unit 540 attached to the upper side of the HST case 313, similar to the L-shaped bracket 538 in the second embodiment (see Figure 30).

[0361] With the configuration described above, the cover unit 800 attached to the main body of the aircraft protects the transmission 53 by covering the upper part of the transmission 53, that is, the upper part of the transmission main body 301 and the HST part 302 from the front, and the front end of the upper part of the transmission 53 from the left side, with the front cover portion 802 and the intermediate cover portion 803. The front cover portion 802 and the intermediate cover portion 803 cover the front and left sides of the device configuration such as the link mechanism 570 and angle sensor 581 (see Figures 22 and 23) located on or near the front side of the transmission 53.

[0362] Furthermore, in the cover unit 800, a wire clamp portion 885 for clamping the brake wire 442 is provided on the upper side of the intermediate cover portion 803. The brake wire 442, which extends diagonally forward and upward from the brake wire stay 443 located on the left side of the transmission case 303, is secured on the upper side of the intermediate cover portion 803 by the wire clamp portion 885.

[0363] The wire clamp portion 885 is provided by fixing a plate-shaped member having a predetermined bending shape to the upper edge of the intermediate cover member 808 by welding or the like. The wire clamp portion 885 has a support surface portion 885a, which is a vertical surface portion extending to the rear from the upper edge of the intermediate cover member 808, and a pair of front and rear clamp pieces 885b provided as protruding pieces on the left side of the support surface portion 885a. The wire clamp portion 885 clamps the brake wire 442 to the intermediate cover member 808 by bending or curving the pair of clamp pieces 885b into a predetermined shape.

[0364] According to the combine harvester 1 of this embodiment, which has the above configuration, the combination harvester 1, which has a transmission 53 located at the front of the traveling body 2, is equipped with a cover unit 800, which protects the components around the transmission 53 from foreign objects.

[0365] The cover unit 800 has a side cover portion 801 that covers the drive belt 323 from the left side, a front cover portion 802 that covers the transmission 53 from the front, and an intermediate cover portion 803 provided between the side cover portion 801 and the front cover portion 802 that covers the transmission 53 from the left front side. With this configuration, it is possible to prevent foreign objects from coming into contact with the drive belt 323 for transmitting power to the transmission 53, thereby suppressing the occurrence of malfunctions such as the drive belt 323 coming off or being damaged, and it is also possible to prevent foreign objects from colliding with or entering the device configurations located on the front side of the transmission 53, thereby suppressing the occurrence of malfunctions in the device configurations.

[0366] In other words, with a configuration that includes a cover unit 800, the effects and advantages obtained by the covering structure of the protective cover 401 according to the first embodiment and the effects and advantages obtained by the covering structure of the protective cover 500 according to the second embodiment can be obtained by the covering structure of the integrated cover unit 800.

[0367] The embodiments described above are examples of the present invention, and the present invention is not limited to the embodiments described above. Therefore, even in embodiments other than those described above, various modifications are possible depending on the design, etc., as long as they do not depart from the technical spirit of the present invention. Furthermore, the effects described in this disclosure are merely examples and are not limiting, and other effects may also exist.

[0368] In the embodiment described above, the combine harvester 1 has a configuration in which the engine 25 is located at the front of the machine frame 6 of the traveling machine body 2, but the location of the engine 25 on the traveling machine body 2 is not particularly limited. The combine harvester according to the present invention may, for example, have a configuration in which the engine is located at the rear of the machine frame. That is, with respect to the drive belt according to the present invention, the first pulley that receives windings of the drive belt 323 together with the transmission input pulley 322 as the second pulley is not limited to the engine output pulley 321 fixed to the first output shaft 25a of the engine 25, but may be any pulley that is rotationally driven by receiving power from a drive source such as an engine. Therefore, the first pulley that receives windings of the drive belt 323 together with the transmission input pulley 322 may, for example, be a pulley that receives the rotational power of a pulley fixed to the output shaft of an engine located at the rear of the machine frame via a power transmission mechanism such as a belt drive mechanism.

[0369] Furthermore, in the above-described embodiment, the combine harvester 1 is equipped with an engine 25 as a drive source, but the drive source according to the present invention is a concept that includes not only various engines but also drive sources other than engines, such as motors.

[0370] This technology can take the following configurations. Note that the configurations described below can be selected and combined as desired.

[0371] (1) A mobile vehicle having left and right travel devices, The drive source mounted on the aforementioned mobile body, A transmission is positioned in the aforementioned traveling body and transmits driving force to the left and right traveling devices, A drive belt for transmitting power from the aforementioned drive source to the transmission, The vehicle includes a drivetrain protection unit that covers at least one of the transmission and the drive belt from at least one side. Work vehicle. (2) The aforementioned drive system protection unit has a protective cover that covers the drive belt from at least one side. The work vehicle described in (1) above. (3) The protective cover is configured to have the upper side of the drive belt open. The work vehicle described in (2) above. (4) The aforementioned drive system protection unit has a lower guard provided below the drive belt to protect the drive belt from below. A work vehicle as described in any one of the above items (1) to (3). (5) The protective cover and the lower guard are integrally configured with respect to each other. The work vehicles described in (4) above. (6) The aforementioned lower guard is provided in an inclined manner in the left-right direction of the aircraft. The work vehicle described in (4) or (5) above. (7) The aforementioned drive belt is wound around a pulley with its axial direction oriented in the left-right direction of the machine body. The protective cover comprises a side cover portion that covers the drive belt from one side (left or right) and a front cover portion that covers the drive belt from the front. A work vehicle as described in any one of the above items (2) to (6). (8) The lower guard is provided in an extensional manner in the longitudinal direction of the machine, with its front end supported by the transmission and its rear end supported by the chassis of the machine. A work vehicle as described in any one of the above items (4) to (6). (9) The lower guard has an opening or gap for discharging foreign matter. A work vehicle as described in any one of items (4) to (7) or (8) above. (10) The aforementioned transmission is located at the front of the vehicle body. The aforementioned drivetrain protection unit has a protective cover provided on the front side of the transmission. The work vehicle described in (1) above. (11) The protective cover comprises a front cover portion that covers the transmission from the front, and a side cover portion that covers the transmission from at least one side on either the left or right side. The work vehicle described in (10) above. (12) The protective cover is configured to have its lower side as the open side. The work vehicle described in (10) or (11) above. (13) The protective cover has a front cover portion that covers the transmission from the front, The aforementioned front cover portion is provided in a state where it is tilted forward when viewed from the side of the aircraft. A work vehicle as described in any one of the above items (10) to (12). (14) The protective cover has a front cover portion that covers the transmission from the front, The front cover portion has a through-hole. A work vehicle as described in any one of the above items (10) to (13). (15) The aforementioned through-hole is a mesh section. The work vehicles described in (14) above. (16) The protective cover is attached to the transmission and fixed to the side of the transmission case of the transmission. A work vehicle as described in any one of the above items (10) to (15). (17) An operating member for operating the transmission mechanism of the transmission is provided on the front side of the transmission. The protective cover is provided so as to cover the operating member from the front. A work vehicle as described in any one of the above items (10) to (16). (18) The machine is equipped with a harvesting unit that is movable up and down relative to the aforementioned traveling machine body, The aforementioned harvesting unit is, A platform including a scraping auger that is rotatable with the left-right direction of the machine as the axis of rotation, The system includes a stalk conveying device, which is mounted in front of the platform and includes a pair of left and right conveying bodies for gripping and conveying stalks, and a harvesting conveying device, which includes a cutting device for cutting stalks. It is configured as a corn header for harvesting corn. A work vehicle as described in any one of the above items (1) to (17). (19) The aforementioned drive system protection unit is A first cover portion covers the drive belt from one side, left or right, A second cover portion that covers the transmission from the front, A third cover portion is provided between the first cover portion and the second cover portion. The work vehicle described in (1) above. [Explanation of Symbols]

[0372] 1. Combine harvester (work vehicle) 2. Mobile Unit 3 Reaping part 5. Crawler section (running gear) 25 Engine (power source) 31 Platform 32 Harvesting and conveying device 33. Grain Strand Conveying Device 34 Cutting device 37. Scoop Auger 53 Transmission 220 Chain conveyor (conveyor) 303 Mission Case 305 Chassis 321 Engine output pulley (pulley) 322 Transmission input pulley (pulley) 323 Drive belt 400 Cover Unit (Protection Unit for Drive System) 401 Protective Cover 402 Lower Guard 403 Support bracket 411 Side cover section 412 Front cover section 421 Lower guard main body 460 opening 470 gaps 471 Pipe section 500 protective cover 501 Cover body 502 Support arm section 503 Front cover section 504 Side cover section 570 Link Mechanism 571 Operating rod (operating component) 572 Link arm (operating member) 600 protective cover 601 Cover body (front cover section) 602 Support arm section 682 Mesh section 640 Cover component 660 Sub-transmission link arm (operating component) 700 Drivetrain protection unit 800 Cover Unit (Protection Unit for Drive System) 801 Side cover section (first cover section) 802 Front cover section (second cover section) 803 Intermediate cover section (third cover section)

Claims

1. A mobile body having left and right travel devices, The drive source mounted on the aforementioned mobile body, A transmission is positioned in the aforementioned traveling body and transmits driving force to the left and right traveling devices, A drive belt for transmitting power from the aforementioned drive source to the transmission, The vehicle includes a drivetrain protection unit that covers at least one of the transmission and the drive belt from at least one side. Work vehicle.

2. The aforementioned drive system protection unit has a protective cover that covers the drive belt from at least one side. The work vehicle according to claim 1.

3. The protective cover is configured to have the upper side of the drive belt open. The work vehicle according to claim 2.

4. The aforementioned drive system protection unit has a lower guard provided below the drive belt to protect the drive belt from below. A work vehicle according to claim 2 or claim 3.

5. The protective cover and the lower guard are integrally configured with respect to each other. The work vehicle according to claim 4.

6. The aforementioned lower guard is provided in an inclined manner in the left-right direction of the aircraft. The work vehicle according to claim 4.

7. The aforementioned drive belt is wound around a pulley with its axial direction oriented in the left-right direction of the machine body. The protective cover comprises a side cover portion that covers the drive belt from one side (left or right) and a front cover portion that covers the drive belt from the front. The work vehicle according to claim 2.

8. The lower guard is provided in an extensional manner in the longitudinal direction of the aircraft, with its front end supported by the transmission and its rear end supported by the chassis of the aircraft. The work vehicle according to claim 4.

9. The lower guard has an opening or gap for discharging foreign matter. The work vehicle according to claim 4.

10. The aforementioned transmission is located at the front of the vehicle body. The aforementioned drivetrain protection unit has a protective cover provided on the front side of the transmission. The work vehicle according to claim 1.

11. The protective cover comprises a front cover portion that covers the transmission from the front, and a side cover portion that covers the transmission from at least one side on either the left or right side. The work vehicle according to claim 10.

12. The protective cover is configured to have its lower side as the open side. A work vehicle according to claim 10 or claim 11.

13. The protective cover has a front cover portion that covers the transmission from the front, The aforementioned front cover portion is provided in a state where it is tilted forward when viewed from the side of the aircraft. The work vehicle according to claim 10.

14. The protective cover has a front cover portion that covers the transmission from the front, The front cover portion has a through-hole. The work vehicle according to claim 10.

15. The aforementioned through-hole is a mesh section. The work vehicle according to claim 14.

16. The protective cover is attached to the transmission and fixed to the side of the transmission case of the transmission. The work vehicle according to claim 10.

17. An operating member for operating the transmission mechanism of the transmission is provided on the front side of the transmission. The protective cover is provided so as to cover the operating member from the front. The work vehicle according to claim 10.

18. The machine is equipped with a harvesting unit that is movable up and down relative to the aforementioned traveling machine body, The aforementioned harvesting unit is, A platform including a scraping auger that is rotatable with the left-right direction of the machine as the axis of rotation, The system includes a stalk conveying device, which is mounted in front of the platform and includes a pair of left and right conveying bodies for gripping and conveying stalks, and a harvesting conveying device, which includes a cutting device for cutting stalks. It is configured as a corn header for harvesting corn. The work vehicle according to claim 10.

19. The aforementioned drive system protection unit is A first cover portion covers the drive belt from one side, left or right, A second cover portion that covers the transmission from the front, A third cover portion is provided between the first cover portion and the second cover portion. The work vehicle according to claim 1.

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