Combine

Abstract

To provide a combine capable of improving detection accuracy of a reaping height detector and suppressing damage to the reaping height detector in a configuration that performs height control of a reaping part.SOLUTION: A combine includes a reaping part 5 having a raising device 22, which is connected to a travelling machine body so as to be liftable, and a reaping height detector 40B for detecting the height of the reaping part 5. The reaping height detector 40B is provided in the state of being supported by a grass dividing frame 34 constituting the frame of the reaping part 5 at a position behind the raising device 22. One or a plurality of grain culm guides 300 for guiding grain culms are disposed on a grain culm conveyance passage side (second conveyance passage 322 side) in a right-left direction with respect to the reaping height detector 40B and above the reaping height detector 40B in a vertical direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a combine harvester equipped with a cutting height detection device for detecting the height of a cutting part from the ground. [Background technology]

[0002] Generally, a combine harvester has a reaping unit in front of the traveling body and a threshing unit on the traveling body, and while traveling, the reaping unit harvests stalks and the threshing unit threshes the stalks. Some combine harvesters have a reaping unit that can be raised and lowered relative to the traveling body, and are equipped with a cutting height detection device (cutting height sensor) for detecting the cutting height in order to control the cutting height (height above the ground), which is the height of the reaping unit from the ground. In such a configuration, the operation of a lifting device such as a hydraulic cylinder that raises and lowers the reaping unit is controlled based on a detection signal from the cutting height detection device, and the cutting height is automatically controlled.

[0003] Some combine harvesters of this type have a cutting height detection device disposed at the rear lower part of a stalk lifting device disposed at the front of the traveling body (see, for example, Patent Document 1). Patent Document 1 discloses a configuration in which two cutting height detection devices are provided for each of the multiple grass dividing frames that make up the cutting section, with one of the cutting height detection devices being disposed at the rear of the lifting device. In addition, each cutting height detection device is disposed in the space below a bent portion of the grass dividing frame with the upper side being the convex side. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5291595 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the above-mentioned conventional technology in which the cutting height detector is disposed at the rear lower part of the lifting device, the stalks to be cut that enter the lifting device through the grass dividing section may come into contact with the cutting height detector, which may cause problems such as inaccurate detection of the cutting height or damage to the cutting height detector.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a combine harvester that is configured to control the height of the cutting section, can improve the detection accuracy of the cutting height detection device, and can suppress damage to the cutting height detection device. [Means for solving the problem]

[0007] The combine harvester of the present invention is a combine harvester equipped with a cutting unit having a lifting device and connected to a running body so that it can be raised and lowered, and a cutting height detection device for detecting the height of the cutting unit, wherein the cutting height detection device is provided at a position rear of the lifting device and supported by a grass dividing frame that constitutes the frame of the cutting unit, and one or more stalk guides for guiding the stalks are arranged on the stalk transport passage side of the cutting height detection device in the left-right direction and above the cutting height detection device in the up-down direction.

[0008] A combine harvester according to another aspect of the present invention is a combine harvester in which the stalk guide is arranged to extend to the side of the cutting height detection device in a plan view.

[0009] In another aspect of the combine of the present invention, the grass dividing frame has a bent portion that is bent upward in a mountain shape at a position rearward of the lower part of the raising device, the cutting height detection device is provided in a space partitioned by the bent portion, and the stalk guide is supported at the front part of the bent portion.

[0010] In another aspect of the combine of the present invention, the grass dividing frame has a first frame portion and a second frame portion which form the bent portion, and between the first frame portion and the second frame portion an intervening member is provided which is fixed to at least one of the first frame portion and the second frame portion, and the cutting height detection device is supported by the intervening member.

[0011] A combine harvester according to another aspect of the present invention has, as the stump guide, a first stump guide supported on the front portion of the bent portion and a second stump guide supported on the intermediate member. Effect of the Invention

[0012] According to the present invention, in a configuration in which the height of the cutting unit is controlled, the detection accuracy of the cutting height detection device can be improved and damage to the cutting height detection device can be suppressed. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a left side view of a combine harvester according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a right side view of a combine harvester according to one embodiment of the present invention. [Diagram 3] FIG. 2 is a plan view showing the configuration of the reaping section of a combine harvester according to one embodiment of the present invention. [Figure 4] FIG. 2 is a front view showing the configuration of the lower part of the harvester of the combine according to one embodiment of the present invention. [Diagram 5] FIG. 2 is a left side cross-sectional view showing the configuration of the lower part of the harvester of the combine according to one embodiment of the present invention. [Figure 6] This is a left side view showing the configuration of a grass dividing section and a cutting height detection device according to one embodiment of the present invention. [Figure 7] 1 is a left side view showing a cutting height detection device and its support structure according to an embodiment of the present invention. FIG. [Figure 8]1 is a right side view showing a cutting height detection device and its support structure according to an embodiment of the present invention. FIG. [Figure 9] 1 is a plan view of a cutting height detection device according to an embodiment of the present invention. [Figure 10] FIG. 2 is a front perspective view showing a sensor unit according to an embodiment of the present invention. [Figure 11] This is a right side view showing the configuration of the front part of the grass dividing section in one embodiment of the present invention. [Figure 12] 2 is a block diagram showing a control configuration of a combine harvester according to one embodiment of the present invention. FIG. [Figure 13] FIG. 2 is a diagram showing an example of an operating unit for reaping work of a combine harvester according to one embodiment of the present invention. [Figure 14] FIG. 2 is a front view showing the arrangement of a stalk guide according to one embodiment of the present invention. [Figure 15] FIG. 2 is a plan view showing the support structure of the stalk guide according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The present invention aims to improve the detection accuracy of the cutting height and suppress damage to the cutting height detection device by providing a stalk guide to prevent the stalk from coming into contact with the cutting height detection device in a configuration having a height-adjustable cutting unit and a cutting height detection device for detecting the cutting height, which is the height of the cutting unit, located behind the lifting device. The following is a description of an embodiment of the present invention.

[0015] [Overall configuration of the combine] The overall configuration of a combine harvester 1 according to this embodiment will be described with reference to Figures 1 and 2. In the following description, the left and right sides of the combine harvester 1 facing the front (left side in Figure 1) are the left and right sides of the combine harvester 1, respectively.

[0016] 1 and 2, the combine harvester 1 according to this embodiment includes a traveling section 2 configured as a crawler-type traveling device having a pair of left and right crawler sections 3, 3, and a traveling body 4 supported by the traveling section 2. The traveling body 4 includes a frame-shaped structural part of the vehicle body of the combine harvester 1. The combine harvester 1 includes an engine 11 mounted on the traveling body 4 as a drive source.

[0017] A reaping unit 5 is provided at the front of the traveling body 4, which harvests and collects stalks of rice, wheat, etc. in the field. A threshing unit 6 which threshes the stalks harvested by the reaping unit 5, and a grain tank 7 which stores the grains removed from the threshing unit 6 are provided side by side on the traveling body 4. The threshing unit 6 is located on the left side of the body, and the grain tank 7 is located on the right side of the body. The combine harvester 1 travels on the traveling unit 2 while harvesting stalks with the reaping unit 5 and threshing with the threshing unit 6.

[0018] Each crawler unit 3 constituting the traveling unit 2 has a track frame 3a extending in the front-rear direction below the traveling body 4, various rotating bodies such as a drive sprocket 3b supported by the track frame 3a, and a track 3c wound around these rotating bodies. The crawler unit 3 is driven by the power of the engine 11 transmitted to the drive sprocket 3b.

[0019] The reaping unit 5 is driven by driving force from the engine 11, harvests the stalks, and transports the harvested stalks to the threshing unit 6, etc. The reaping unit 5 is provided in front of the traveling body 4 across substantially the entire width of the combine harvester 1. The reaping unit 5 is provided so as to be able to rise and fall relative to the traveling body 4.

[0020] The threshing section 6 has a threshing drum 6a with a rotation axis extending in the front-to-rear direction, and a stump supplying device provided to the left of the threshing drum 6a. The stump supplying device holds the base of the stump cut by the reaping section 5 and transports the stump rearward in a lying position with the ear tip facing the threshing drum 6a. The stump supplying device includes a feed chain 6b wound around multiple sprockets with a rotation axis extending in the left-to-right direction, and a stump supplying clamping body 6c that cooperates with the feed chain 6b to clamp the base of the stump.

[0021] Below the threshing section 6 on the traveling machine body 4, a sorting section 8 is provided which sorts the material threshed by the threshing section 6. The sorting section 8 has a rocking sorting device 8a, a wind sorting device and a grain conveying device. The sorting section 8 rocks and sorts the material that has fallen from the threshing section 6 using the rocking sorting device 8a, and wind sorts the material after rocking and sorting using the wind sorting device. The sorting section 8 conveys grains from the material after wind sorting to the right towards the grain tank 7 using the grain conveying device, and blows straw dust, dust and the like backwards using the wind sorting device and discharges them outside the machine body. The grains conveyed by the grain conveying device towards the grain tank 7 are stored in the grain tank 7.

[0022] A discharge auger 9 is rotatably provided at the rear right end of the traveling body 4 as a grain discharge device that discharges grains from the grain tank 7 to the outside. The discharge auger 9 has a discharge port 9a at its tip, and discharges grains stored in the grain tank 7 from the discharge port 9a. The grains discharged from the discharge port 9a are dumped into the bed of a truck, a container, or the like.

[0023] On the traveling machine body 4, behind the threshing section 6, there is provided a straw waste processing section 10 which processes the straw waste after threshing by the threshing section 6. The straw waste processing section 10 has a straw waste conveying device 10a and a straw waste cutting device 10b. The straw waste conveying device 10a conveys the threshed stump (stump) by the threshing section 6 rearward and discharges it outside the machine body or conveys it to the straw waste cutting device 10b. The straw waste cutting device 10b cuts the stump transported from the straw waste conveying device 10a and discharges it outside the machine body.

[0024] A driver's unit 14 is provided on the traveling body 4 in front of the grain tank 7. A handle unit 15 serving as a steering operation unit is provided in front of the driver's unit 14, and a driver's seat 16 is provided behind the handle unit 15. A side operation unit 12 is provided to the side of the driver's seat 16, and includes various operating tools including a main shift lever 17, and various operation units such as dials and switches, which are arranged on a side column 19 (see FIG. 13).

[0025] A prime mover unit including an engine 11 is provided below the driving unit 14. The engine 11 is, for example, a diesel engine. The power of the engine 11 is transmitted to various devices provided in each part of the combine 1 via a transmission or the like.

[0026] The reaping unit 5 will be described with reference to Figures 1 to 6. The reaping unit 5 has a reaping support machine frame 20 as a reaping frame, and is configured by supporting a grass dividing board 21, a raising device 22, a raking device 23, a cutting blade device 24, a stalk transport device 25, etc. on the reaping support machine frame 20. Each device of the reaping unit 5 operates by transmitting power from the engine 11.

[0027] The grass dividing board 21 is an example of a grass dividing body constituting the grass dividing section 50 of the cutting section 5, and is provided at the front part of the cutting section 5. The grass dividing board 21 has a tapered shape, and divides culms vegetated in the field.

[0028] The lifting device 22 is a device that forms the lower transport structure in the harvesting section 5. The lifting device 22 is provided on the rear side of the grass dividing board 21, and has a lifting case 22b that extends in the front-to-rear direction in a plan view, and tines 22a, which are multiple lifting claws connected by a chain provided inside the case 22b. The lifting device 22 is provided so that the lifting case 22b is inclined upward toward the rear in a side view. The multiple tines 22a are provided so that they protrude sideways from the lifting case 22b when moving in the transport direction (upward direction) of the culms relative to the lifting case 22b. The multiple tines 22a are operated to lift up the fallen culms.

[0029] The raking device 23 is provided behind the lifting device 22, and includes a chain-driven conveying mechanism 23a and a rotary packer 23b, and raks in the stalks. In addition, in Fig. 3, only the components of the raking device 23 provided at the left end are shown, and the other components are omitted.

[0030] The cutting blade device 24 is a clipper-type device that cuts the base of the raised culms. The culm transport device 25 is a device that transports the culms that have been cut, and it joins multiple culms together, clamps and transports them upward and rearward, and delivers them to the starting end of the feed chain 6b of the threshing section 6 in a horizontally lying position.

[0031] As shown in Fig. 1, the reaping support machine frame 20 is supported by a support frame 26 arranged in a downwardly-descending manner on the front side of the traveling machine body 4. The support frame 26 is provided in approximately the center in the left-right direction of the machine body, and the reaping support machine frame 20 is provided on the front side of the support frame 26.

[0032] As shown in Fig. 3, the reaping support machine frame 20 has a horizontal frame 31 extending in the left-right direction of the machine body, and a plurality of grass dividing frames 30 (32, 33, 34) extending forward from the horizontal frame 31. The reaping support machine frame 20 is supported by the support frame 26 at the horizontal frame 31.

[0033] The horizontal frame 31 is a straight frame part mainly made of square pipe-shaped members. The grass division frame 30 is a frame part mainly made of round pipe-shaped members, has a predetermined bent or curved shape, and extends in the front-rear direction in a plan view. The grass division frame 30 is supported in a cantilever manner by fixing and supporting the rear end or rear part to the horizontal frame 31.

[0034] The multiple grass dividing frames 30 are arranged in parallel at a predetermined interval in the left-right direction. The number of grass dividing frames 30 is one more than the number of mowing rows of the combine harvester 1. The combine harvester 1 according to this embodiment is a three-row mower, and four grass dividing frames 30 are provided. The combine harvester 1 has, as the grass dividing frames 30, two grass dividing frames 32 that are the first grass dividing frames located on both the left and right sides, one grass dividing frame 33 that is the second grass dividing frame located second from the left, and one grass dividing frame 34 that is the third grass dividing frame located third from the left.

[0035] The lifting devices 22 are arranged between adjacent grass frames 30 on the left and right, for a total of three lifting devices 22. The lower part of the lifting case 22b of the lifting device 22 is connected and supported to the front of each grass frame 30 via a lifting device support part 35 composed of a support arm, mounting plate, etc.

[0036] A grass dividing board 21 is attached to the front of each grass dividing frame 30. Two types of grass dividing boards 21, a relatively large one and a relatively small one, are provided in a predetermined arrangement as the multiple grass dividing boards 21. In this embodiment, a relatively large grass dividing board 21 is provided for the grass dividing frames 32 on both the left and right sides and the third grass dividing frame 34 from the left, and a relatively small grass dividing board 21 (21A) is provided for the second grass dividing frame 33 from the left.

[0037] The reaping unit 5 having the above-mentioned configuration is attached to the traveling machine body 4 so as to be rotatable about a predetermined rotation axis via a reaping lifting cylinder 18 (see FIG. 1) serving as a lifting device. In other words, the reaping unit 5 is provided so as to be able to be raised and lowered relative to the traveling machine body 4 by a rotational action due to the extension and contraction of the reaping lifting cylinder 18. The reaping lifting cylinder 18 is a hydraulic cylinder, and is provided between the traveling machine body 4 and the support frame 26. The rear end of the support frame 26 is supported rotatably about a left-right axis relative to the traveling machine body 4 as a rotation fulcrum for the lifting and lowering action of the reaping unit 5 by the reaping lifting cylinder 18.

[0038] As described above, the combine harvester 1 has the reaping unit 5 provided so as to be able to rise and fall relative to the traveling body 4. The combine harvester 1 is equipped with a cutting height detection device 40 and a control device 200 (see FIG. 12) in order to control the cutting height (height above the ground), which is the height of the reaping unit 5 from the ground surface G1. In this configuration, the control device 200 controls the operation of the reaping lifting cylinder 18 that raises and lowers the reaping unit 5 based on a detection signal from the cutting height detection device 40, thereby automatically controlling the cutting height.

[0039] The operation of the cutting lift cylinder 18 is controlled by controlling the operation of a solenoid valve, which is a control valve. The control device 200 controls the cutting height by controlling the operation of the control valve of the cutting lift cylinder 18 based on a detection signal from the cutting height detection device 40.

[0040] The automatic control of the cutting height controls the operation of the control valve of the cutting lifting cylinder 18 so as to maintain the cutting height of the cutting unit 5 at a set value based on a detection signal from the cutting height detection device 40, and automatically controls the lifting and lowering of the cutting unit 5. In the automatic control of the cutting height, the control device 200 controls the height of the cutting unit 5 so that the cutting height detected by the cutting height detection device 40 becomes a preset target value (hereinafter referred to as the "target cutting height value").

[0041] In other words, when the detected cutting height is below the target cutting height value, the control device 200 raises the cutting unit 5, and when the detected cutting height is above the target cutting height value, the control device 200 lowers the cutting unit 5, thereby controlling the lifting and lowering of the cutting unit 5 so that the height of the cutting unit 5 is maintained at a height corresponding to the target cutting height value.

[0042] In addition, in the automatic control of the mowing height, the target mowing height value may be set as a value within a predetermined range (a value having a width). In this case, the control device 200 controls the elevation of the mowing unit 5 so that the height of the mowing unit 5 is maintained within the range of heights corresponding to the target mowing height value by raising the mowing unit 5 when the detected mowing height is below the lower limit of the target mowing height value and lowering the mowing unit 5 when the detected mowing height is above the upper limit of the target mowing height value.

[0043] The driving unit 14 is provided with an operating unit for adjusting the cutting height, and for example, during automatic control of the cutting height, control is performed that prioritizes adjustment of the cutting height by operating the operating unit for adjusting the cutting height. As the operating unit for adjusting the cutting height, for example, a cutting lift lever 36 (see FIG. 12) for lifting and lowering the cutting unit 5 is provided.

[0044] By manually operating the mowing lift lever 36, the operation of the control valve of the mowing lift cylinder 18 is controlled via the control device 200, and the mowing unit 5 is raised and lowered. By operating the mowing lift lever 36 from the neutral position to the upward side, the mowing lift cylinder 18 is controlled to extend, and the mowing unit 5 is raised. By operating the mowing lift lever 36 from the neutral position to the downward side, the mowing lift cylinder 18 is controlled to contract, and the mowing unit 5 is lowered. The operating unit for adjusting the mowing height may be configured with an operating tool other than a lever, such as a switch operating unit (mowing lift switch).

[0045] As described above, the combine 1 comprises a cutting unit 5 having a grass dividing section 50 including a grass dividing board 21 and a lifting device 22, which is connected to the running body 4 so that it can be raised and lowered, and a cutting height detection device 40 for detecting the cutting height, which is the height of the cutting unit 5.

[0046] In this embodiment, the combine 1 is equipped with, as cutting height detection devices 40, a cutting height detection device 40A which is a first cutting height detection device arranged behind the relatively small grass dividing board 21A which is the second from the left, and a cutting height detection device 40B which is a second cutting height detection device arranged behind the central one of the three raising devices 22.

[0047] The cutting height detection device 40A is provided in a state supported by the second grass division frame 33 from the left, and the cutting height detection device 40B is provided in a state supported by the third grass division frame 34 from the left. Thus, the combine harvester 1 is provided with two cutting height detection devices 40, one of the cutting height detection devices 40A is provided in a position in front of the lifting device 22 in a state supported by the grass division frame 33 constituting the cutting support machine frame 20, which is the frame of the cutting section 5, and the other cutting height detection device 40B is provided in a position behind the lifting device 22 in a state supported by the grass division frame 34 constituting the cutting support machine frame 20. However, the number of cutting height detection devices 40 provided in the combine harvester 1 and the position at which the cutting height detection device 40 is provided are not limited.

[0048] [Configuration of cutting height detection device] The configuration of the cutting height detection device 40 will be described with reference to Figures 6 to 10. As shown in Figures 6 to 10, the cutting height detection device 40 includes a device main body 41, a grounding body 42, a cutting height sensor 43 which is a sensor for detecting the cutting height, and a unit support 44 which is a member for supporting the device main body 41.

[0049] In the cutting height detection device 40, the device body 41, the grounding body 42, and the cutting height sensor 43 form an integrated sensor unit 45 (see FIG. 10), and this sensor unit 45 is supported so as to be rotatable about an axis in the left-right direction relative to the unit support body 44. The unit support body 44 is supported so as to be rotatable about an axis in the front-rear direction relative to the grass dividing section 50.

[0050] The height-of-cutting detection device 40 as a whole is supported rotatably about an axis in the front-to-rear direction relative to the grass dividing section 50, and the sensor unit 45 is supported rotatably about an axis in the left-to-right direction relative to the unit support body 44. Rotation of the height-of-cutting detection device 40 about its front-to-rear axis and rotation of the sensor unit 45 about its left-to-right axis are performed in response to an external force acting on the height-of-cutting detection device 40. Below, a state in which no external force is acting on the height-of-cutting detection device 40 is defined as a reference state, and the height-of-cutting detection device 40 in its basic reference state will be described.

[0051] In the sensor unit 45, the device main body 41 has a configuration in which various gears, springs, etc. are supported on predetermined shafts inside a case 51 made of, for example, a metal casting. The case 51 has a left-right two-part structure consisting of a right case body 52 that forms the main body of the case 51 and a left case body 53 that covers the left side of the right case body 52 like a lid. The right case body 52 and the left case body 53 are fixed to each other by fixing bolts 55 at four points around the periphery of the case 51 in a side view. The case 51 has a roughly rectangular outer shape with the longitudinal direction being the front-rear direction (the left-right direction in FIG. 7) in a side view.

[0052] In the sensor unit 45, the grounding body 42 extends downward from the rear side of the rear end of the case 51. The cutting height sensor 43 is provided in a manner such that it is attached to the right side surface of the case 51.

[0053] The unit support 44 is a member in the form of a narrow plate-like member that is bent to have a predetermined shape in a plan view, and extends in the front-rear direction. As shown in Fig. 9, the unit support 44 has a first support 46 that mainly constitutes the left side of the unit support 44, and a second support 47 that mainly constitutes the right side of the unit support 44.

[0054] The unit support 44 has a left side surface portion 44a that is elongated in the front-rear direction, a front surface portion 44b that is formed so as to form a right angle from the front end portion of the left side surface portion 44a toward the right, and a right side surface portion 44c that is elongated in the front-rear direction and formed from the right end portion of the front surface portion 44b toward the rear. All of these surface portions that form the unit support 44 are vertical surface portions. In other words, the first support 46 and the second support 47 are both plate-like members that are bent to form a predetermined shape in a plan view, and the left side surface portion 44a, the front surface portion 44b, and the right side surface portion 44c are formed by these supports.

[0055] As shown in FIG. 9, the first support 46 has an outer wall surface portion 46a forming the left side surface portion 44a of the unit support 44, a front wall surface portion 46b forming a part of the front surface portion 44b of the unit support 44, and an inner wall surface portion 46c formed so as to form a right angle from the right end portion of the front wall surface portion 46b toward the rear. The first support 46 has a bent shape that is approximately "J" shaped in a plan view by the outer wall surface portion 46a, the front wall surface portion 46b, and the inner wall surface portion 46c. Also, as shown in FIG. 9, the second support 47 has a side wall surface portion 47a forming the right side surface portion 44c of the unit support 44, a front wall surface portion 47b forming a part of the front surface portion 44b of the unit support 44, and an inclined wall surface portion 47c formed at the corner portion formed by the side wall surface portion 47a and the front wall surface portion 47b and having a chamfered shape in a bottom view.

[0056] The left side surface portion 44a of the unit support 44 (the outer wall surface portion 46a of the first support 46) is a plate-like portion that is elongated in the front-rear direction and has a plate thickness direction in the left-right direction. The rear end portion of the left side surface portion 44a extends rearward beyond the rear end portion of the case 51 in the front-rear direction. The front surface portion 44b of the unit support 44 is a plate-like portion whose plate thickness direction is in the front-rear direction. The front surface portion 44b is formed by the front wall surface portion 46b of the first support 46 and the front wall surface portion 47b of the second support 47.

[0057] The first support 46 and the second support 47 are connected to each other by being fastened and fixed by a screw body 48 and a nut 49 that penetrate the overlapping portion between the front wall surface portions 46b, 47b. The screw body 48 has a threaded portion that protrudes forward from the front wall surface portion 47b of the second support 47, and the nut 49 is screwed into this protruding portion. The fixing portions by the screw body 48 are provided at two locations, one above and one below.

[0058] The right side surface portion 44c (side wall surface portion 47a of the second support 47) of the unit support 44 is a plate-like portion that is elongated in the front-rear direction and has a plate thickness direction in the left-right direction, and is provided so as to face the left-right direction relative to the left-right direction. The position of the rear end of the right side surface portion 44c in the front-rear direction is substantially the same as the rear end of the case 51.

[0059] The unit support 44 is open at the top and bottom, and has a shape that, in plan view, is substantially rectangular with the longitudinal direction being the front-to-rear direction, with a left side surface portion 44a, a front surface portion 44b, and a right side surface portion 44c. The left side surface portion 44a, the front surface portion 44b, and the right side surface portion 44c of the unit support 44 are positioned to the left, the front, and the right of the sensor unit 45 (see FIG. 10), respectively, to form a peripheral wall portion that surrounds the periphery of the sensor unit 45. In other words, the sensor unit 45 is provided so that the entirety or substantially the entirety is located in the space surrounded by the unit support 44 in plan view.

[0060] The components of the sensor unit 45 will be described below. The device body 41 is provided on a front fixed shaft 61, which is a first shaft, so as to be rotatable up and down. The front fixed shaft 61 is a support shaft whose axial direction is in the left-right direction, and supports the sensor unit 45 so as to be rotatable around a first axis P1 (see FIGS. 7 and 9).

[0061] The front fixed shaft 61 is located in the device body 41 near the front end of the case 51. The front fixed shaft 61 extends leftward from the inner wall surface portion 46c with the right end portion fixed to the inner wall surface portion 46c of the first support 46 via the support plate 56. The front fixed shaft 61 is a fixed shaft supported in a cantilever manner by the inner wall surface portion 46c. The support plate 56 is fixed at two points, upper and lower, by bolts 57 in a state where it overlaps the inside (left side) of the inner wall surface portion 46c. Note that the front fixed shaft 61 may be any shaft fixed to the unit support 44. The front fixed shaft 61 is supported so as to be rotatable relative to the case 51. That is, the case 51 is supported so as to be rotatable relative to the front fixed shaft 61.

[0062] In this way, the sensor unit 45 is provided so as to be rotatable up and down in a cantilevered state with the left-right direction as the axial direction relative to the front fixed shaft 61, which is a fixed shaft fixed to the unit support 44 (see arrow A1 in FIG. 7). That is, the unit support 44 supports the device body 41 of the sensor unit 45 by the front fixed shaft 61 so as to be rotatable up and down about the first axis P1.

[0063] With respect to the rotation of the sensor unit 45 around the first axis P1 relative to the unit support 44, the sensor unit 45 is biased in a downward rotation direction (clockwise direction as viewed from the left side) by a case return member, which is an elastic member such as a spring provided in the case 51. The case return member is, for example, a torsion spring having linear extensions at both ends of a coil-shaped main body. In this case, the case return member is provided in a state in which the front fixed shaft 61 penetrates the main body, one extension is engaged with the front fixed shaft 61 side and the other extension is engaged with the case 51 side, and applies a force that presses the case 51 downward toward the front fixed shaft 61 side. As a result, the sensor unit 45 is biased in a direction of downward rotation around the axis of the front fixed shaft 61.

[0064] A case return spring 58 for urging the sensor unit 45 in a downward rotation direction relative to the front fixed shaft 61 is provided on the portion of the front fixed shaft 61 protruding to the right from the case 51 (see FIG. 9). The case return spring 58 is a torsion spring having linear extensions 58a on both ends of a coil-shaped main body.

[0065] The case return spring 58 is provided with the front fixed shaft 61 penetrating the main body, one extension 58a inserted into and locked in a locking hole 52a (see FIG. 8) formed on the right side of the front part of the right case body 52 of the case 51, and the other extension 58a locked in a predetermined manner to the front surface 44b of the unit support 44, and exerts a force pressing the case 51 downward toward the front fixed shaft 61. This biases the sensor unit 45 in a direction to rotate downward around the axis of the front fixed shaft 61.

[0066] Meanwhile, with regard to rotation of the sensor unit 45 relative to the unit support 44, downward rotation of the sensor unit 45 is restricted to a standard position by a case stopper bolt 59 provided on the case 51. The case stopper bolt 59 is screwed from the left into the front-to-rear middle part of the upper edge of the left case body 53, with its head protruding from the left case body 53 to the left.

[0067] With this configuration, in the standard state, the head of the case stopper bolt 59 abuts against the upper edge of the left side surface portion 44a of the unit support 44, thereby preventing the sensor unit 45 from rotating downward relative to the unit support 44. Note that the locking portion of the sensor unit 45 with respect to the unit support 44 may be a protruding portion formed as a part of the left case body 53.

[0068] In this way, the sensor unit 45 is restricted from rotating downward from the reference state relative to the unit support 44 while being biased in the downward rotation direction with respect to rotation about the front fixed shaft 61. Therefore, when an external force from the ground G1 or the like acts on the sensor unit 45 to rotate the sensor unit 45 upward about the front fixed shaft 61, the sensor unit 45 rotates upward against the biasing forces of the case return member and the case return spring 58 in the case 51. When the action of the external force is released, the sensor unit 45 in the upward rotated state automatically rotates downward due to the biasing forces of the case return spring 58 and the like, and returns to the reference state position due to the locking action of the case stopper bolt 59 on the unit support 44.

[0069] The grounding body 42 is rotatably supported by a rear rotating shaft 62, which is a second shaft located behind the front fixed shaft 61 with respect to the device body 41. The rear rotating shaft 62 is a support shaft whose axial direction is in the left-right direction, and supports the grounding body 42 rotatably with respect to the case 51 of the device body 41 about the second axis P2.

[0070] The rear rotating shaft 62 is located near the rear end of the case 51, and is supported for relative rotation with respect to the case 51 via a bearing member such as a bush. The grounding body 42 is fixed to a portion of the rear rotating shaft 62 that protrudes to the right from the case 51. The grounding body 42 has a grounding body main body portion 42a that is a portion that extends downward from the device main body 41, and a support arm portion 42b that is a support portion for the rear rotating shaft 62. The grounding body main body portion 42a and the support arm portion 42b are both plate-like portions having a predetermined shape.

[0071] The grounding body main body 42a is a spatula-shaped portion that gradually widens downward in width (left-right dimension) from the top to the bottom. The support arm 42b extends from the upper end of the grounding body main body 42a, which is located immediately behind the case 51, to the right front side along the case 51 and is fixed to the rear rotating shaft 62. The right end of the rear rotating shaft 62 passes through the front part of the support arm 42b, and the support arm 42b is fastened and fixed to the rear rotating shaft 62 by a nut 68 or the like. A threaded portion is formed at the right end of the rear rotating shaft 62 into which the nut 68 is screwed.

[0072] In this manner, the grounding body 42 is fixed to the rear rotating shaft 62 and rotates integrally with the rear rotating shaft 62 about the second axis P2. The grounding body 42 is provided so as not to interfere with the case 51 within its rotation range. With regard to the rotational position of the grounding body 42, the position of the grounding body 42 in the cutting height detection device 40 in the reference state is defined as the reference position.

[0073] The ground contact body 42 rotates as follows relative to the device body 41 around the rear rotation shaft 62. That is, with the tip of the ground contacting the ground G1, the ground contact body 42 rotates (rotates backward) to move the tip side backward due to drag resistance (ground sliding resistance) from the ground G1 caused by the combine harvester 1 moving forward (see arrow C1 in FIG. 7). On the other hand, the ground contact body 42 rotates (rotates forward) to move the tip side forward due to ground sliding resistance caused by the combine harvester 1 moving backward (see arrow C2 in FIG. 7).

[0074] The cutting height sensor 43 is a sensor that detects the amount of rotation of the grounding body 42 about the rear rotating shaft 62. The cutting height sensor 43 is provided with respect to an intermediate rotating shaft 70, which is the third shaft provided in the cutting height detection device 40, and detects the amount of rotation of the grounding body 42 about the rear rotating shaft 62 from the amount of rotation of the intermediate rotating shaft 70.

[0075] The intermediate rotating shaft 70 is a support shaft whose axial direction is in the left-right direction, and is supported via a bearing member such as a bush to be relatively rotatable about a third axis P3 relative to the case 51 of the device body 41. The intermediate rotating shaft 70 is located midway between the front fixed shaft 61 and the rear rotating shaft 62 in the front-rear direction.

[0076] The cutting height sensor 43 is a rotary type potentiometer, and detects the rotational position of the grounding body 42 via the intermediate rotating shaft 70 and the rear rotating shaft 62. The cutting height sensor 43 is fixed to the right case body 52 at two points, one above and one below, with bolts 73 on the right side surface of the right case body 52 (see FIG. 8).

[0077] The cutting height sensor 43 is connected to the right end of the intermediate rotating shaft 70, and directly detects the rotational position of the intermediate rotating shaft 70 about the third axis P3, using the intermediate rotating shaft 70 as a detection axis. The cutting height sensor 43 has a main body 43a and a connector 43b to which a signal line is connected in the main body 43a. One end of a wire harness (not shown) serving as a signal line is connected to the connector 43b. The cutting height sensor 43 is connected to the control device 200 provided on the traveling machine body 4 side by the wire harness. Note that the cutting height sensor 43 may have a configuration in which a signal line is directly extended from the main body as a connection configuration to the control device 200.

[0078] The intermediate rotating shaft 70 rotates by receiving the rotational power of the rear rotating shaft 62 accompanying the rotation of the ground contact body 42. The intermediate rotating shaft 70 receives the rotational power of the rear rotating shaft 62 via gears or the like provided for each of the rear rotating shaft 62 and the intermediate rotating shaft 70. The rotation of the intermediate rotating shaft 70 is detected by the cutting height sensor 43. The ground contact body 42 uses a ground contact body returning member which is an elastic member such as a spring provided in the case 51, and is provided so that the ground contact body 42 is positioned at a predetermined reference position in the absence of the action of an external force with respect to the rotation around the rear rotating shaft 62 by setting the biasing force (torque) of the ground contact body returning member, the case returning member, etc.

[0079] In the height-of-cut detection device 40 having the above-described configuration, the grounding body 42 is arranged to rotate about the rear pivot shaft 62 with respect to the device body 41, which is in a state where rotation about the front fixed shaft 61 is stopped, when the grounding body 42 is located rearward of the reference position, for example, when the combine harvester 1 moves forward and the like, when the grounding body 42 is pressed from the front and rotates rearward from the reference position, the device body 41 does not rotate about the front fixed shaft 61, and only the grounding body 42 rotates about the rear pivot shaft 62 relative to the device body 41.

[0080] The cutting height sensor 43 detects the amount of rotation of the grounding body 42 backward from the reference position. That is, the rearward relative rotation of the grounding body 42 with respect to the device body 41 from a state in which the grounding body 42 is in the reference position is detected by the cutting height sensor 43 as the rotation for detecting the cutting height.

[0081] On the other hand, with regard to the relative rotation of the grounding body 42 with respect to the device body 41, the rotation of the grounding body 42 forward from the reference position is accompanied by the upward rotation of the case 51. That is, when the grounding body 42 rotates forward from the reference position, the device body 41 as a whole rotates upward about the front fixed shaft 61 in conjunction with the rotation of the grounding body 42. Here, when the grounding body 42 rotates forward from the reference position relative to the device body 41, the intermediate rotating shaft 70 does not rotate, and the cutting height sensor 43 does not detect the rotation of the intermediate rotating shaft 70.

[0082] As described above, the cutting height detection device 40 is configured so that the cutting height sensor 43 detects the amount of rotation of the grounding body 42 when the grounding body 42 is rotated rearward from the reference position relative to the device body 41.

[0083] By using the cutting height detection device 40 having the above-mentioned configuration, the combine harvester 1 detects the height (cutting height) of the cutting part 5 based on the detection signal from the cutting height sensor 43. As described above, the cutting height detection device 40 detects the rearward rotation of the ground contact body 42, and therefore detects the cutting height mainly when the body of the combine harvester 1 moves forward.

[0084] In the cutting height detection device 40, the cutting height sensor 43 detects the height of the grass dividing board 21 from the ground G1, i.e., the cutting height, by detecting the rotational position of the intermediate rotating shaft 70, which rotates in conjunction with the rotation of the grounding body 42. The detection signal of the cutting height sensor 43 is sent to the control device 200 by a wire harness. The control device 200 receives the detection signal from the cutting height sensor 43, and based on the detection signal, operates the cutting lifting cylinder 18 (see FIG. 1) to adjust the cutting height so as to hold the cutting height calculated from the detection result at a set value.

[0085] In a configuration in which the cutting height sensor 43 is attached to the outside of the case 51 of the device body 41, the device body 41 is provided with a sensor cover 170 that covers the cutting height sensor 43. The sensor cover 170 is fixed to the case 51 with a bolt 176.

[0086] [Support structure of cutting height detection device] The support structure of the cutting height detection device 40 will be described using Figures 6 to 9 and 11. The support structure of the cutting height detection device 40 described here is the support structure of the cutting height detection device 40B arranged on the rear side of the raising device 22. The cutting height detection device 40 is supported by the support structure of the unit support body 44 for the grass dividing section 50 so as to be rotatable so as to swing left and right about an axis line O1 (see Figures 7 and 9) that runs along the front-rear direction.

[0087] As shown in Figures 6 to 8, the grass dividing section 50 for supporting the cutting height detection device 40B includes a grass dividing frame 34 provided at the bottom of the cutting section 5 and a grass dividing board 21 provided in front of the grass dividing frame 34.

[0088] The grass dividing frame 34 is made of pipe-shaped members and has a predetermined curved shape in side view. The grass dividing frame 34 has, from the front to the rear, a front horizontal frame portion 101, a front inclined frame portion 102, a rear inclined frame portion 103, and a rear inclined frame portion 104 as frame parts that form the side view shape.

[0089] The front horizontal frame portion 101 is a horizontal portion. The front end portion of the front horizontal frame portion 101 becomes the tip portion of the grass division frame 34. The front inclined frame portion 102 is a linear inclined portion that rises rearward and forms an obtuse angle with the front horizontal frame portion 101. In a side view, the angle that the front inclined frame portion 102 makes with the horizontal line is, for example, about 70°.

[0090] The rear inclined frame portion 103 is a rearwardly downwardly inclined portion that, together with the front inclined frame portion 102, forms an upwardly convex mountain shape. The rear inclined frame portion 103 has a front inclined portion 103a with a relatively gentle rearward downward slope at its front portion and a rear inclined portion 103b with a steeper rearward downward slope than the front inclined portion 103a at its rear portion, and the front inclined portion 103a and the rear inclined portion 103b form an obtuse angled bend. In a side view, the angle that the front inclined portion 103a makes with the horizontal line is, for example, about 20°, and the angle that the rear inclined portion 103b makes with the horizontal line in a side view is, for example, about 60°.

[0091] The rear inclined frame portion 104 is a linear inclined portion that rises to the rear and forms an obtuse angle with the rear inclined portion 103b of the rear inclined frame portion 103. In a side view, the angle that the rear inclined frame portion 104 makes with the horizontal line is, for example, about 10°. The rear end portion of the rear inclined frame portion 104 becomes the base end portion of the grass dividing frame 34.

[0092] The grass dividing frame 34 has a curved front corner 106 at the corner formed by the front horizontal frame portion 101 and the front inclined frame portion 102, and a curved rear corner 107 at the corner formed by the rear inclined portion 103b of the rear inclined frame portion 103 and the rear inclined frame portion 104. The rear corner 107 is located slightly higher than the front corner 106. The grass dividing frame 34 has the rear end portion of the rear inclined frame portion 104 located above the horizontal frame 31, and the rear inclined frame portion 104 is fixed to the horizontal frame 31 via plate-shaped support members 108, 109, etc., fixed to the horizontal frame 31 (see FIG. 6).

[0093] In the grass dividing frame 34, the front inclined frame part 102 and the rear inclined frame part 103 form a bent part 110 that is bent upward in a mountain shape. That is, the grass dividing frame 34 has the front inclined frame part 102 as the first frame part that forms the bent part 110, and the rear inclined frame part 103 as the second frame part that forms the bent part 110. In this way, in the grass dividing frame 34, a convex part with the upper side convex is formed in the middle part in the vertical direction as the bent part 110. That is, the front inclined frame part 102 and the rear inclined frame part 103 form a mountain-shaped convex part that follows a substantially triangular shape with the corners of these frame parts as the apex.

[0094] As shown in Figure 5, the grass dividing frame 34 has the front inclined frame part 102 positioned at the rear of the lower part of the lifting device 22, and is inclined so as to follow the inclination of the lifting device 22 in the rearward tilted position. Therefore, the bent part 110 of the grass dividing frame 34 is positioned at the rear of the lower part of the lifting device 22. In this way, the grass dividing frame 34 has a bent part 110 bent upward in a mountain shape at the lower rear position of the lifting device 22.

[0095] The grass dividing frame 34 has a front frame member 111 forming the front horizontal frame portion 101 and the front inclined frame portion 102, and a rear frame member 112 forming the rear inclined frame portion 103 and the rear inclined frame portion 104. The front frame member 111 and the rear frame member 112 are both pipe-shaped members having a predetermined bent shape. The grass dividing frame 34 has the upper end portion (front end portion) of the rear frame member 112 fixed to the rear side peripheral wall portion of the upper end portion (rear end portion) of the front frame member 111 by welding or the like. At the fixing portion between these frame members, both frame members are fixed in a state of being fitted together in such a manner that the peripheral wall portion of the front frame member 111 closes the front opening of the rear frame member 112.

[0096] In addition, the grass splitting frame 34 has a front end of the front horizontal frame section 101 as a tapered section 101a that follows the outer shape of a truncated cone. The front end of the front horizontal frame section 101 is formed by a substantially cylindrical tip member 113 that is inserted and fixed to the front side of the front frame member 111. The tip member 113 has a main body tube section 113a with the same diameter as the outer diameter of the front frame member 111, and an insertion section 113b that is provided on the rear side of the main body tube section 113a and is a reduced diameter section relative to the main body tube section 113a. The tapered section 101a is formed at the front end of the main body tube section 113a.

[0097] The tip member 113 is fixed to the front frame member 111 by inserting the insertion portion 113b into the front frame member 111 from the front side with a fixing portion 115 provided on the upper side of the front part of the front frame member 111. The fixing portion 115 includes a bolt that penetrates the peripheral wall of the front frame member 111 and engages with the insertion portion 113b, and a nut that screws onto the bolt.

[0098] The grass dividing board 21 has a grass dividing board main body 121 and a rib plate section 122 provided on the rear side of the grass dividing board main body 121. The grass dividing board main body 121 is a plate-shaped member having a curved or bent shape with the front side being the convex side in a planar cross-sectional view, and has a pointed shape that gradually narrows from the rear side to the front side in a front view and a plan view. The grass dividing board main body 121 has a curved shape with the front lowered and the rear lower side being the convex side in a side view. The rib plate section 122 is a plate-shaped part whose board thickness direction is the left-right direction, and is provided as an integral part of the grass dividing board main body 121 on the rear side of the lower part of the grass dividing board main body 121. The configuration in which the rib plate section 122 is provided on the grass dividing board main body 121 has a left-right symmetrical or approximately left-right symmetrical shape.

[0099] The grass dividing section 50 also includes a hitch 125 as a grass dividing board support member provided on the rear side of the grass dividing board 21. The hitch 125 is a roughly rectangular plate-like member, and is fixed to the tip of the grass dividing frame 34. A cutout 125a is formed in the rear lower part of the hitch 125, which follows the side view shape of the tip of the grass dividing frame 34, which has a tapered portion 101a. The cutout 125a has a horizontal side portion along the outer peripheral surface of the front horizontal frame section 101, an oblique side portion along the outer peripheral surface of the tapered portion 101a, and a vertical side portion along the tip surface of the tapered portion 101a.

[0100] The hitch 125 is located in the center of the grass dividing frame 34 in the left-right direction, and is fixed to the grass dividing frame 34 by welding or the like in such a manner that the tip of the grass dividing frame 34 is fitted from below into the cutout portion 125a. The grass dividing frame 34 is fixed to the hitch 125 at the tip member 113.

[0101] The grass dividing board 21 is attached to the hitch 125. The grass dividing board 21 is fastened to the hitch 125 at two points, front and rear, with bolts 127 and nuts 128, with the rear part of the rib plate portion 122 overlapping the front part of the hitch 125 from the right side. In this way, the hitch 125 is fixed to the grass dividing frame 34, thereby supporting the grass dividing board 21 in front of the grass dividing frame 34. In other words, the grass dividing board 21 is attached to the tip of the grass dividing frame 34 via the hitch 125.

[0102] Further, the grass dividing section 50 is provided with a left guide rod 123 which is a first guide rod and a right guide rod 124 which is a second guide rod. The left guide rod 123 and the right guide rod 124 are both made of a metal rod-shaped member having a predetermined bent shape.

[0103] The left guide rod 123 is arranged on the left side of the rib plate portion 122 so as to slope downward toward the front and along the lower edge of the front-to-rear middle part of the grass dividing board main body 121 in a side view. The front end part of the left guide rod 123 is fixed by welding or the like to a part near the upper edge of the approximately front-to-rear middle part on the left side of the rib plate portion 122. The left guide rod 123 has a straight rear part 123a bent outwardly to the left and right (left side) from its front part, which extends from the left edge of the grass dividing board main body 121 diagonally backward to the left in a plan view (see FIG. 3) and diagonally upward to the left in a front view (see FIG. 4).

[0104] The left guide rod 123 guides the base side of the planted culm to the lifting device 22 located in the center at the rear. On the right side of the left-end grass dividing board 21, a guide rod 129a is provided symmetrically to the left guide rod 123, and on the left side of the right-end grass dividing board 21, a guide rod 129b is provided in the same manner as the left guide rod 123 (see Figures 3 and 4). These guide rods 129a and 129b guide the base side of the planted culm to the corresponding lifting device 22.

[0105] The right guide rod 124 is located on the right side of the rib plate portion 122, below and to the rear of the grass dividing board main body 121, and is arranged so as to form an upward inclination toward the rear in a side view. The right guide rod 124 is fixed and supported to the rear end portion of the hitch 125 via an attachment plate 126. The attachment plate 126 is a bent plate-like member that is approximately L-shaped in a front view.

[0106] The mounting plate 126 is fastened to the hitch 125 at two points, top and bottom, with bolts 116 and nuts 117, with one of its curved surfaces overlapping the rear part of the hitch 125 from the right side behind the rib plate portion 122. The mounting plate 126 has the other surface protruding rightward from the hitch 125, and the vicinity of the tip of the right guide rod 124 is fixed to it by welding or the like.

[0107] The right guide rod 124 has a front edge portion 124a that is inclined rightward from the front side to the rear side in a plan view, an intermediate edge portion 124b that extends upward toward the rear in a side view from the rear side of the front edge portion 124a, and a rear edge portion 124c that extends upward toward the rear at a steeper slope than the intermediate edge portion 124b in a side view (see FIG. 11). The right guide rod 124 has the front edge portion 124a as a fixed portion for the mounting plate 126. In a plan view, the intermediate edge portion 124b of the right guide rod 124 is inclined in the same direction as the front edge portion 124a, with the angle of inclination in the front-to-rear direction being smaller than that of the front edge portion 124a.

[0108] The right guide rod 124 has its rear end (upper end) positioned in the front-to-rear direction at approximately the same position as the rear end (upper end) of the grass dividing board main body 121 (see FIG. 11). Also, the right guide rod 124 has most of its rear side positioned between the hitch 125 and the front inclined frame part 102 in the front-to-rear direction, and the inclination angle of the rear edge part 124c is approximately the same as the inclination angle of the front inclined frame part 102 of the grass dividing frame 34 (see FIG. 6).

[0109] The cutting height detection device 40 is supported so as to be rotatable around a fore-aft axis relative to the grass dividing unit 50 having the above-mentioned configuration. The cutting height detection device 40 has a shaft support part 130 on its front side as a support part for the grass dividing unit 50, and is supported by this shaft support part 130 so as to be rotatable around a fore-aft axis O1 as a rotation axis.

[0110] The pivot support 130 is provided on the rear side of the front corner 106 relative to the grass dividing frame 34. The pivot support 130 has a boss portion 132, which is a support portion provided on the rear side of the front corner 106, and a support shaft portion 131 provided at the front end of the unit support 44 and supported by the boss portion 132. The pivot support 130 has a configuration in which the support shaft portion 131, which protrudes forward from the front wall surface portion 46b of the front portion 44b of the unit support 44, is supported by the boss portion 132 provided on the grass dividing frame 34 side. In other words, the front end side of the cutting height detection device 40 is attached to the grass dividing frame 34 side via the boss portion 132.

[0111] The support shaft portion 131 protrudes forward from the front wall surface portion 46b as an integral part of the unit support body 44, and its axis coincides with the axis line O1. The boss portion 132 is a hollow cylindrical portion with an open rear side, and is provided by fixing a cylindrical member to the grass dividing frame 34 via a connecting plate 140 and a lower support plate 141. The boss portion 132 has a front end portion that is tapered to follow the outer shape of a truncated cone.

[0112] The connecting plate 140 is an example of an intermediate member provided between the front inclined frame portion 102 and the rear inclined frame portion 103 of the grass dividing frame 34. The rear inclined frame portion 104 is a plate-like member having a substantially triangular shape, and is provided on the inside (lower side) of the bending portion 110 formed by the front inclined frame portion 102 and the rear inclined frame portion 103, with the plate thickness direction oriented in the left-right direction. The connecting plate 140 is provided so as to close a part (mainly the upper part) of the substantially triangular space portion 100 on the inside of the bending portion 110 in a side view.

[0113] The connecting plate 140 is located in the center of the left-right direction with respect to the grass dividing frame 34, and is provided in a state of being fixed to the front inclined frame part 102 and the rear inclined frame part 103. In detail, the connecting plate 140 has a front oblique side part 140a along the rear edge of the outer peripheral surface of the front inclined frame part 102, a rear oblique side part 140b along the front side (lower side) of the outer peripheral surface of the front inclined part 103a of the rear inclined frame part 103, and a lower oblique side part inclined downward to the front on the lower side of the connecting plate 140, and these sides form a roughly triangular outer shape. The connecting plate 140 is fixed to each frame part 102, 103 by welding or the like, with the front oblique side part 140a and the rear oblique side part 140b serving as contact parts for the front inclined part 103a of the front inclined frame part 102 and the rear inclined frame part 103, respectively. In addition, the connecting plate 140 only needs to be fixed to at least one of the front inclined frame portion 102 and the rear inclined frame portion 103, so that it is fixed to the grass dividing frame 34.

[0114] The connecting plate 140 has a rectangular support protrusion 140c protruding downward from the lower side of the front oblique side portion 140a. The connecting plate 140 is fixed to the boss portion 132 by welding or the like, with the lower edge of the support protrusion 140c being in contact with the outer circumferential surface of the boss portion 132 from above.

[0115] The lower support plate 141 is a plate-like member having a substantially rectangular shape, and is fixed to the rear side of the front corner 106 of the grass dividing frame 34 by welding or the like, with the left-right direction being the plate thickness direction and the longitudinal direction being the front-rear direction. The lower support plate 141 is located in the center of the grass dividing frame 34 in the left-right direction, and its rear part is located below the support protrusion 140c. A cutout 141a is formed on the upper side of the rear part of the lower support plate 141 according to the side view shape of the boss part 132 having a tapered part on the front end side. The lower support plate 141 is fixed to the boss part 132 by welding or the like in a manner in which the boss part 132 is fitted from above into the cutout part 141a.

[0116] As described above, the boss portion 132 is sandwiched between the support protrusion portion 140c of the connecting plate 140 and the lower support plate 141 from above and below, and is fixed to these plates by welding or the like, so as to be supported in a fixed state on the grass dividing frame 34 side.

[0117] A cover plate 142 is provided below the lower support plate 141. The cover plate 142 has a generally isosceles triangular shape with the front side at the apex side when viewed from the bottom (see FIG. 15), and is provided horizontally at a position approximately at the same height as the lower end of the front horizontal frame portion 101. The cover plate 142 positions the lower support plate 141 on the left-right center portion, and is fixed to the lower support plate 141 by welding or the like. The front end of the cover plate 142 is located below the front corner portion 106 and the rear end is located immediately in front of the unit support body 44 in the front-rear direction, covering the pivot portion 130 from below.

[0118] The support shaft portion 131 is rotatably supported by the boss portion 132 via a bearing member such as a bush with its front portion inserted into the boss portion 132, and is prevented from coming loose from the boss portion 132 by a lock screw 137 and a lock nut 138 (see Figure 9).

[0119] In this way, the pivot support part 130 supports the support shaft part 131 provided on the front part of the unit support body 44 by the boss part 132 via the connecting plate 140 and the lower support plate 141 to the grass dividing frame 34. As a result, the pivot support part 130 supports the front side of the cutting height detection device 40 rotatably with the front-to-rear direction as the rotation axis relative to the grass dividing section 50. The cutting height detection device 40 is supported by the pivot support part 130 to the connecting plate 140, and is supported in a cantilever manner relative to the grass dividing section 50.

[0120] As described above, the cutting height detection device 40 supports the unit support 44 so that it can rotate around the front-to-rear axis O1 relative to the grass dividing section 50, thereby supporting the sensor unit 45 supported by the unit support 44 so that it can swing left and right.

[0121] The cutting height detection device 40 is elastically positioned so as to be located at a predetermined neutral position with respect to rotation about an axis in the front-rear direction by a return spring 147 provided on the shaft support portion 130. The return spring 147 is a so-called torsion spring, and the coil-shaped portion passes through the rear portion of the boss portion 132 and is engaged with a locking pin 148 that protrudes forward from the front wall surface portion 46b above the boss portion 132.

[0122] The return spring 147 has extensions 147a at both ends positioned on the left and right sides of the locking pin 148, and the extensions 147a elastically clamp the locking pin 148 from both the left and right sides. The return spring 147 also has extensions 147a positioned on both the left and right sides of the front lower part of the connecting plate 140 positioned above the locking pin 148, and the left and right extensions 147a elastically clamp the connecting plate 140. The locking pin 148 is positioned immediately behind the support protrusion 140c of the connecting plate 140, and a protruding portion formed on the rear upper side of the support protrusion 140c of the connecting plate 140 is positioned between the left and right extensions 147a.

[0123] According to this configuration, when an external force of a predetermined magnitude or greater that rotates the cutting height detection device 40 about the axis O1 acts on the cutting height detection device 40, the cutting height detection device 40 rotates against the elastic force of the return spring 147 with one extension portion 147a pressed by the locking pin 148 in accordance with the rotation direction and the other extension portion 147a locked to the connecting plate 140. Then, when the external force is no longer acting, the elastic force of the return spring 147 returns the cutting height detection device 40 to the neutral position.

[0124] According to the above-described arrangement and support configuration of the cutting height detection device 40, the cutting height detection device 40 is provided in a space 100 partitioned by a bent portion 110 of the grass dividing frame 34. The space 100 is a space portion that is approximately triangular in side view on the inside of the convex portion formed by the front inclined frame portion 102 and the rear inclined frame portion 103 in the grass dividing frame 34, and is a space portion whose lower side is the open side between the front corner portion 106 and the rear corner portion 107.

[0125] In the space 100 defined by such bent portion 110, cutting height detection device 40 is disposed below connecting plate 140. Cutting height detection device 40 is provided so that most of the upper side is located within space 100 in the up-down direction in side view. Cutting height detection device 40 is also provided so that the entirety or substantially the entirety is located within space 100 in the front-to-rear direction in side view. It is sufficient that cutting height detection device 40 is provided so that at least a portion is located within space 100.

[0126] [Mowing height detection device operation] The operation of the cutting height detection device 40 will now be described. During normal operation by the combine harvester 1, that is, when the machine body is in forward motion, the cutting height is controlled based on the cutting height detection value by the cutting height detection device 40 so that the cutting height is maintained at a set value. The cutting height is detected when the rotation position of the grounding body 42 relative to the device body 41 is rearward of the reference position.

[0127] When the machine body moves forward, the ground contact body 42, which slides with its tip in contact with the ground surface G1, rotates rearward from a reference position about the rear rotating shaft 62 relative to the case 51 of the device body 41 due to ground sliding resistance (see arrow C1 in FIG. 7). The ground contact body 42 rotates integrally with the rear rotating shaft 62 about the second axis P2, and the rotation of the rear rotating shaft 62 is transmitted to the intermediate rotating shaft 70 via gears or the like. The rotation of the intermediate rotating shaft 70 is detected by the cutting height sensor 43, and the cutting height is detected based on the amount of rotation of the intermediate rotating shaft 70.

[0128] Furthermore, if a lateral external force acts on height-of-cutting detection device 40, for example when the machine is steered with grounding body 42 on the ground, height-of-cutting detection device 40 will rotate about axis O1 in the front-rear direction by pivot support 130 and escape. When the lateral external force acting on height-of-cutting detection device 40 is no longer acting, the biasing structure of return spring 147 and locking pin 148 will return height-of-cutting detection device 40 to a predetermined neutral position.

[0129] [Combine control configuration] The control configuration of the combine harvester 1 will be described with reference to FIG. 12. As shown in FIG. 12, the combine harvester 1 includes a control device 200. The control device 200 controls each part of the combine harvester 1 based on input signals from various sensors and the like included in the combine harvester 1. The control device 200 includes a central processing unit (CPU) as an arithmetic processing device that executes various arithmetic processing and control, storage devices such as random access memory (RAM) and read only memory (ROM), input / output devices (input / output circuits) such as an input / output interface for data input / output, and peripheral circuits such as a clock circuit, all connected via a bus or the like. The CPU of the control device 200 performs arithmetic processing according to various programs stored in the ROM or the like.

[0130] 12, the combine harvester 1 has, as components electrically connected to the input device (input circuit) of the control device 200, a cutting height sensor 43 of the cutting height detection device 40, a cutting height adjustment dial 202 as a cutting height target value setting operation unit, and an automatic cutting height switch 205. The control device 200 receives input signals from these sensors, switches, etc., and generates a control signal based on these signals.

[0131] The control device 200 controls the lifting and lowering of the cutting unit 5 by operating the cutting lift cylinder 18 so that the cutting height is maintained at the target cutting height value based on a detection signal from the cutting height sensor 43. The control device 200 controls the extension and contraction operation of the cutting lift cylinder 18 by controlling the operation of a solenoid valve 221 for hydraulic control of the cutting lift cylinder 18.

[0132] A mowing height target value used for controlling the elevation of the mowing unit 5 is set and stored in the control device 200. The mowing height target value is set in the control device 200 by a mowing height adjustment dial 202.

[0133] As shown in Fig. 13, in the driver's section 14, the mowing height adjustment dial 202 is provided on the left side panel section 151L out of the side panel sections 151 (151L, 151R) provided on both the left and right sides of the steering case section 152 constituting the handle section 15. The side panel section 151 forms a surface section that is inclined upward in front so as to face the operator seated in the driver's seat 16. The steering case section 152 protrudes upward from the left and right side panel sections 151, and houses a wheel support shaft and the like that supports the steering wheel 150 as a steering operation tool constituting the handle section 15.

[0134] 13, the mowing height adjustment dial 202 is disposed near the left end of the side panel portion 151L. Moreover, the mowing height adjustment dial 202 is located to the left of the upper part of the steering wheel 150 in a plan view, and is disposed so as not to overlap the area of ​​the steering wheel 150.

[0135] The mowing height adjustment dial 202 is an operating tool for adjusting the target mowing height value in stages, and is provided as a cylindrical protrusion (knob) that is rotated. In this embodiment, the mowing height adjustment dial 202 is configured to be able to adjust the target mowing height value in five stages, for example, in a range of 10 to 50 mm. A scale display unit 203 showing the scale of "1" to "5" corresponding to the rotational position of the mowing height adjustment dial 202 is provided around the mowing height adjustment dial 202 on the surface of the side panel portion 151L.

[0136] The lifting and lowering control of the reaping unit 5 performed by the control device 200 in the combine harvester 1 having the above configuration will be described. In the lifting and lowering control of the reaping unit 5 according to this embodiment, for example, of the detection signals of the two cutting height detection devices 40 provided in the combine harvester 1, the detection signal that detects the lower cutting height is used. However, the manner in which the two cutting height detection devices 40 are used is not particularly limited.

[0137] The control device 200 controls the elevation of the cutting unit 5 by performing cutting height control, including the above-mentioned automatic control of the cutting height, based on a detection signal from the cutting height detection device 40. The cutting height control is performed while the combine harvester 1 is performing a cutting operation.

[0138] The control device 200 has, as control modes for the mowing height control, an automatic mowing height mode, which is a first control mode that performs the automatic control of the mowing height described above, and an automatic lift mode, which is a second control mode that controls the mowing unit 5 to rise to a fixed height under predetermined conditions. Hereinafter, the mowing height control that includes these two control modes and is based on the detection signal of the mowing height detection device 40 will be referred to as "automatic mowing height control."

[0139] The automatic mowing height mode of the automatic mowing height control is a mode in which the height of the mowing unit 5 is controlled so that the mowing height detected by the mowing height detection device 40 becomes a predetermined target value (mowing height target value) and the height of the mowing unit 5 is maintained at a constant height relative to the ground surface G1 during mowing operation. The automatic lift mode of the automatic mowing height control is a mode in which, based on the mowing height detected by the mowing height detection device 40, the mowing unit 5 is raised to a constant height when the height of the mowing unit 5 becomes lower than the set height relative to the ground surface G1 during mowing operation.

[0140] The automatic mowing height switch 205 functions as a mode changeover switch for switching between an automatic mowing height mode and an automatic lift mode in the automatic mowing height control. The automatic mowing height switch 205 is provided on the side panel portion 151L in the same manner as the mowing height adjustment dial 202, and is disposed in the vicinity of the mowing height adjustment dial 202, as shown in FIG.

[0141] The automatic mowing height switch 205 is disposed near the mowing height adjustment dial 202, thereby constituting a mowing height control operation unit 210 set together with the mowing height adjustment dial 202 on the left side near the handle unit 15. The mowing height control operation unit 210 is operated by an operator seated in the driver's seat 16. Also, in Figure 13, the illustrated portion of the mowing height control operation unit 210 in the driver's unit 14 is partially cut out and separately shown enlarged.

[0142] The automatic mowing height switch 205 is a rotary switch that is switched by a rotation operation, and has a knob portion 205a for rotation operation. The automatic mowing height switch 205 is disposed in a position (upper right position) inside (right) and above (upper right position) the mowing height adjustment dial 202 in the left-right direction on the side panel portion 151L. Therefore, the mowing height adjustment dial 202 and the automatic mowing height switch 205 are disposed in diagonal positions in the substantially rectangular operation unit area 209 of the mowing height control operation unit 210. The automatic mowing height switch 205 is also located on the left side of the upper part of the steering wheel 150 in a plan view, and is disposed so as not to overlap with the area range of the external shape of the steering wheel 150 (see FIG. 13).

[0143] On the surface of side panel portion 151L, near (below) automatic mowing height switch 205, there is provided a mode display unit 206 that displays characters corresponding to the control mode selected by the rotational position of automatic mowing height switch 205. Mode display unit 206 is provided below automatic mowing height switch 205.

[0144] The mode display unit 206 has a first display unit 206a that displays the characters "AUTOMATIC MOWING HEIGHT" when in a rotation position corresponding to the automatic mowing height mode, a second display unit 206b that displays the characters "OK LIFT" when in a rotation position corresponding to the automatic lift mode, and a third display unit 206c that displays the characters "OFF" when in a rotation position corresponding to the off mode in which the automatic mowing height control is turned off. In other words, by rotating the automatic mowing height switch 205, three states are switched between: an automatic mowing height mode state of the automatic mowing height control, an automatic lift mode state of the automatic mowing height control, and an off state of the automatic mowing height control.

[0145] When working in the automatic mowing height mode, with engine 11 started, automatic mowing height switch 205 is operated to select the automatic mowing height mode. With automatic mowing height mode selected, mowing work is started, and during mowing work, mowing height adjustment dial 202 is adjusted to one of the scales "1" to "5." As a result, the mowing height corresponding to the scale set by mowing height adjustment dial 202 is set as the target mowing height value, and the mowing height is controlled so as to be automatically maintained at the target mowing height value based on the detection signal from mowing height detection device 40.

[0146] When working in the automatic lift mode, the automatic lift mode is selected by operating the automatic mowing height switch 205 with the engine 11 started. With the automatic lift mode selected, mowing work is started, and during mowing work, if it is detected that the mowing height detected by the mowing height detection device 40 is equal to or less than a set height (e.g., 10 mm), the mowing unit 5 is controlled to automatically rise a predetermined amount (e.g., 1 to 2 cm). Also, with the automatic lift mode selected, if the machine is stopped traveling or if it is detected that the mowing height detected by the mowing height detection device 40 is equal to or more than another set height (e.g., 20 mm), the mowing unit 5 is controlled to stop rising. The set height and predetermined amount for the automatic lift mode are preset and stored in the control device 200.

[0147] In this embodiment, the cutting height control operation unit 210 is provided on the left side panel portion 151L, but it may be provided on the right side panel 151R.

[0148] [About the Grain Strain Guide] The combine harvester 1 is provided with a plurality of stalk guides 300 as a configuration for guiding the movement of the stalks during reaping work so as to move the stalks away from the height-of-cutting detector 40. The stalk guides 300 are rod-shaped guide bodies constituted by elongated round metal members having a predetermined curved or bent shape.

[0149] As shown in Figures 3, 6 and 14, the combine harvester 1 according to this embodiment is provided with three stalk guides 300 for guiding the stalks on the stalk transport passage side in the left-right direction relative to the height-of-cutting detection device 40 and above the height-of-cutting detection device 40 in the up-down direction. As shown in Figure 3, in this embodiment, the stalk transport passage side in the left-right direction for the height-of-cutting detection device 40 (40B) provided for the third grass dividing frame 34 from the left is the right side (upper side in Figure 3).

[0150] In this embodiment, in the reaping unit 5 having a three-row reaping configuration, the two left rows of culms of the three rows to be reaped are transported diagonally upward and rearward through a first transport path 321 between the two left and center lifting devices 22 of the three raising devices 22. The one right row of culms of the three rows to be reaped is transported diagonally upward and rearward through a second transport path 322 between the two center and right raising devices 22. That is, the space between the two left and center lifting devices 22 with the protruding sides of the multiple tines 22a facing each other becomes the first transport path 321, which is the transport path for the two left rows of culms, and the protruding side (left side) of the tines 22a of the right raising device 22 becomes the second transport path 322, which is the transport path for the one right row of culms.

[0151] In this type of stalk transport passage configuration using the three lifting devices 22 in the harvesting section 5, the transport passage closer to the grass dividing frame 34 supporting the cutting height detection device 40B in the left-right direction is the second transport passage 322. The second transport passage 322 is located on the right side of the grass dividing frame 34, i.e., to the right of the cutting height detection device 40B. In this way, in the left-right direction, the side of the transport passage closer to the grass dividing frame 34 supporting the cutting height detection device 40B (the second transport passage 322 side) is the transport passage side for the cutting height detection device 40B.

[0152] The conveying passage side for such a cutting height detection device 40B can be said to be the side opposite in the left-right direction to the side where the lifting device 22 attached to the grass dividing frame 34 by the lifting device support part 35 is arranged. Also, the conveying passage side for the cutting height detection device 40B can be said to be the passage side where the stalks are conveyed by the action of the multiple tines 22a between the lifting device 22 located on the right side and the lifting device 22 located in the center in the left-right direction.

[0153] All three stalk guides 300 are disposed above the height-of-cut detection device 40. That is, with respect to the vertical arrangement of the three stalk guides 300, the lower ends of all three stalk guides 300 are positioned above the height-of-cut detection device 40.

[0154] The combine 1 has, as the culm guide 300, a first front culm guide 301 and a second front culm guide 302 as first culm guides supported on the front part of the bending portion 110 of the grass dividing frame 34, and an auxiliary culm guide 303 as a second culm guide supported on the connecting plate 140.

[0155] Of the three culm guides 300, the first front culm guide 301 and the second front culm guide 302 are supported at the front of the bent portion 110 of the grass dividing frame 34. The first front culm guide 301 and the second front culm guide 302 have their front ends supported by the front inclined frame portion 102, which forms the front portion of the bent portion 110, via a support plate 310 provided at the front of the front inclined frame portion 102. In other words, the two front culm guides 301, 302 have their front ends supported by the support plate 310. These front culm guides 301, 302 start from the supported portion on the support plate 310 and extend from the supported portion diagonally upward toward the rear in a side view.

[0156] The first front stalk guide 301 is provided so that the extension portion from the supported portion to the rear side of the support plate 310 is substantially linear with an upwardly upward angle in a side view. The angle of the extension portion of the first front stalk guide 301 with respect to the horizontal line in a side view is substantially 40°.

[0157] The second front culm guide 302 has an extension portion extending from the supported portion to the rear side of the support plate 310 below the first front culm guide 301, and extends approximately parallel to the first front culm guide 301 in a side view. In detail, the second front culm guide 302 has a front extension portion 302a inclined upward toward the rear in a side view, and a rear extension portion 302b inclined upward toward the rear in a steeper portion than the front extension portion 302a and approximately parallel to the first front culm guide 301. The second front culm guide 302 has an obtuse angled bend in a side view due to the front extension portion 302a and the rear extension portion 302b. The angle of the front extension portion 302a to the horizontal line in a side view is approximately 20°. In addition, the second front stalk guide 302 is formed of a rod-shaped member that is slightly thinner than the first front stalk guide 301.

[0158] The support structure of the first front stalk guide 301 and the second front stalk guide 302 will be described with reference to Figs. 7, 8 and 15. The support plate 310 supporting the front ends of the first front stalk guide 301 and the second front stalk guide 302 is a rectangular plate-shaped member, with the left-right direction being the plate thickness direction, and the longitudinal direction in a side view being oriented along the inclination direction of the front inclined frame part 102, and is provided in a state of being fixed to the upper and lower middle parts of the front inclined frame part 102. The rear part of the support plate 310 is fixed to the outer peripheral surface of the right side of the front inclined frame part 102 by welding or the like, and the front part protrudes forward from the front inclined frame part 102. The support plate 310 supports the front ends of the first front stalk guide 301 and the second front stalk guide 302 on the protruding support part 310a, which is a part protruding forward from the front inclined frame part 102.

[0159] The support plate 310 supports the first front stalk guide 301 in a sandwiched state together with the first clamping plate 311 provided on the right side of the protruding support portion 310a. The support plate 310 supports the second front stalk guide 302 in a sandwiched state together with the second clamping plate 312 provided on the left side of the protruding support portion 310a.

[0160] The first clamping plate 311 and the second clamping plate 312 are both plate-like members having a substantially rectangular outer shape that conforms to the side view shape of the protruding support portion 310a of the support plate 310. Both clamping plates 311, 312 are disposed on the support plate 310 so that their outer shapes match the shape of the protruding support portion 310a, and are fastened and fixed to the support plate 310 at two locations on both sides in the longitudinal direction by bolts 316 and nuts 317 that pass through these plates.

[0161] Bolt 316 passes through first clamping plate 311, support plate 310, and second clamping plate 312 from the right side, and receives nut 317 screwed into the portion protruding from second clamping plate 312. Bolt 316 is, for example, a welded bolt fixed to first clamping plate 311. A hole portion is formed in support plate 310, through which bolt 318 passes.

[0162] The first clamping plate 311 and the second clamping plate 312 each have protruding edges 311a, 312a that are bent or curved so as to protrude inward (toward the support plate 310) at the edges of both long sides so as to secure a space between them and the support plate 310 (see FIG. 15). Each clamping plate 311, 312 has a pair of protruding edges 311a, 312a, and thus has a flat, generally U-shaped cross section. Each clamping plate 311, 312 has a pair of protruding edges 311a, 312a, and thus a space is formed between the support plate 310 and each clamping plate 311, 312, with both sides of the protruding support part 310a being open in the longitudinal direction.

[0163] The first front stalk guide 301 has a folded portion 301c folded back to form a substantially U-shape at the front end portion sandwiched between the support plate 310 and the first clamping plate 311. The folded portion 301c has a folded shape that positions the tip of the first front stalk guide 301 on the rear lower side of the lower bolt 316 and surrounds the outside of the two bolts 316 along the outer shape of the first clamping plate 311. The folded portion 301c of the first front stalk guide 301 extends downward from the front side of the bolt 316 at the lower opening of the space between the support plate 310 and the first clamping plate 311, folds back toward the rear side to the right of the support plate 310, and extends diagonally upward toward the rear in a side view. In the first front grain stalk guide 301 , the portion folded back to the rear, located below the first clamping plate 311 , becomes the lower end portion of the first front grain stalk guide 301 .

[0164] The second front stalk guide 302, like the first front stalk guide 301, has a folded-back portion 302c folded back to form a substantially U-shape at the front end portion sandwiched between the support plate 310 and the second clamping plate 312. The folded-back portion 302c has a folded-back shape that positions the tip of the second front stalk guide 302 on the front lower side of the lower bolt 316 and surrounds the outside of the two bolts 316 along the outer shape of the second clamping plate 312. The second front stalk guide 302 extends downward from the rear side of the bolt 316 at the lower opening of the space between the support plate 310 and the second clamping plate 312 by the folded-back portion 302c, and folds back toward the rear side to the right of the support plate 310 and extends diagonally upward toward the rear in a side view. In the second front grain stalk guide 302 , the folded back portion located below the second clamping plate 312 becomes the lower end portion of the second front grain stalk guide 302 .

[0165] The auxiliary stalk guide 303 has a front end supported by the connecting plate 140. The auxiliary stalk guide 303 extends rearward in a side view from the supported portion of the connecting plate 140 as a starting point, and further extends obliquely upward toward the rear.

[0166] The auxiliary culm guide 303 has a front horizontal portion 303a extending horizontally backward and a rear inclined portion 303b inclined upwardly backward in side view. The auxiliary culm guide 303 has the rear inclined portion 303b positioned below the rear extension portion 302b of the second front culm guide 302 in side view and extending approximately parallel to the rear extension portion 302b. The auxiliary culm guide 303 is formed of a rod-shaped member that is slightly thicker than the first front culm guide 301.

[0167] The support structure of the auxiliary stump guide 303 will be described with reference to Figures 7, 8 and 15. The auxiliary stump guide 303 has its front end supported on the upper part of the connecting plate 140. The connecting plate 140 supports the front end of the auxiliary stump guide 303 in a sandwiched state together with the clamping plate 313 provided on its right side. The support portion of the auxiliary stump guide 303 by the clamping plate 313 is located at approximately the same height as the support plate 310 in the vertical direction and is located behind the support plate 310.

[0168] The clamping plate 313 is a plate-like member having a roughly rectangular outer shape, and is arranged on the right side of the upper part of the connecting plate 140 with its longitudinal direction oriented in the front-to-rear direction. The clamping plate 313 is fastened to the connecting plate 140 at two points on both sides in the longitudinal direction by bolts 318 and nuts 319 that pass through these plates.

[0169] The bolt 318 passes through the clamping plate 313 and the connecting plate 140 from the right side, and a nut 319 is screwed onto the portion of the bolt 318 protruding from the connecting plate 140. The bolt 318 is, for example, a welded bolt that is fixed to the clamping plate 313 by welding. The connecting plate 140 has a hole through which the bolt 318 passes.

[0170] Similar to the first clamping plate 311, the clamping plate 313 has protruding edges 313a that are bent or curved at both long side edges so as to protrude inward (toward the connecting plate 140) to ensure a space between the connecting plate 140 and the clamping plate 313. The clamping plate 313 has a pair of protruding edges 313a, so that the clamping plate 313 has a flat, generally U-shaped cross section. The clamping plate 313 has a pair of protruding edges 313a, so that a space is formed between the connecting plate 140 and the clamping plate 313, with both sides of the clamping plate 313 in the longitudinal direction being open.

[0171] The auxiliary stalk guide 303 has a folded-back shape 303c that is folded back to form a substantially U-shape at the front end that is clamped by the connecting plate 140 and the clamping plate 313. The folded-back shape 303c has a folded-back shape that positions the tip of the auxiliary stalk guide 303 on the front upper side of the front bolt 318 and surrounds the outside of the two bolts 318 along the outer shape of the clamping plate 313. The auxiliary stalk guide 303 extends forward from the lower side of the bolt 318 at the front opening of the space between the connecting plate 140 and the clamping plate 313 by the folded-back shape 303c, and folds back toward the rear side through a portion that is bent upward to the right of the connecting plate 140, extending backward in a side view. In the auxiliary stalk guide 303, the lower side of the folded-back shape 303c becomes the lower end of the auxiliary stalk guide 303.

[0172] As described above, the three stalk guides 300 supported on the bending portion 110 of the grass dividing frame 34 via the support plate 310 or the connecting plate 140 are arranged to protrude to the side (right side) of the cutting height detection device 40 when viewed in a plan view.

[0173] As shown in Figures 3 and 14, all three culm guides 300 have a curved or bent shape that bulges out to the right in plan and front views. Of the three culm guides 300, the first front culm guide 301 and the second front culm guide 302 have a shape that bulges out to form a roughly mountain shape with the top on the right side in plan and front views. In plan views, the first front culm guide 301 and the second front culm guide 302 bulge out to a position where the end (top) of the shape bulging out to the right overlaps with the movement trajectory of the tine 22a protruding out to the left of the lifting device 22 located on the right side.

[0174] In addition, in a plan view, the front portions of the first front culm guide 301 and the second front culm guide 302 are substantially parallel to each other and extend in a straight line from the front end diagonally backward to the right, forming front extension portions 301a, 302a, and the second front culm guide 302 is positioned on the left and right inner side (left side) of the first front culm guide 301. In addition, in a plan view, the rear portions of the first front culm guide 301 and the second front culm guide 302 are substantially parallel to each other and extend in a straight line diagonally backward to the left, forming rear extension portions 301b, 302b, and the second front culm guide 302 is positioned on the left and right outer side (right side) of the first front culm guide 301. That is, in a plan view, the second front culm guide 302 has the front extension 302a, which forms its front part, positioned substantially entirely on the left-right inner side of the first front culm guide 301, and intersects with the first front culm guide 301 at the front-rear middle part, with the rear part positioned on the left-right outer side of the first front culm guide 301. In addition, in a plan view, curved apexes 301d, 302d that convexly extend to the right are formed between the front extensions 301a, 302a and the rear extensions 301b, 302b of the first front culm guide 301 and the second front culm guide 302 (see FIG. 14), and the apex 302d of the second front culm guide 302 is positioned behind and outwardly (to the right) of the apex 301d of the first front culm guide 301 (see FIG. 3).

[0175] Of the three culm guides 300, the auxiliary culm guide 303 is disposed on the left and right inner side (left side) of the first front culm guide 301 and the second front culm guide 302. In a plan view, the auxiliary culm guide 303 has a front portion that extends in a substantially straight line from the front end diagonally rearward to the right, and has an overall curved shape with the right side convex, forming a bulging protruding shape.

[0176] All three stalk guides 300 are extended so that their rear ends are positioned near or on the cutting blade device 24 in a plan view. All three stalk guides 300 have their front ends supported by the grass dividing frame 34 as clamped parts, and the parts behind the clamped parts are unsupported parts that are not supported by other members, so that they are supported in a cantilevered manner.

[0177] According to the combine harvester 1 having the above-described configuration, in a configuration for controlling the height of the cutting section 5, the detection accuracy of the cutting height detection device 40 can be improved and damage to the cutting height detection device 40 can be suppressed.

[0178] In a configuration in which the cutting height detection device 40B is disposed at the lower rear of the raising device 22, the cutting height detection device 40B faces the second transport passage 322 through which the stalks 400 (see FIG. 14) that are divided by the grass dividing board 21 and raised and transported by the raising device 22 pass. In addition, as the machine body moves forward, the stalks are divided into left and right by the grass dividing board 21, and some of them may pass through the second transport passage 322.

[0179] The stalks 400 passing through the second conveying passage 322 may come into contact with the device body 41 or the grounding body 42 of the cutting height detection device 40B, causing the sensor unit 45 to malfunction, resulting in an unstable detection value of the cutting height and possibly causing damage to the cutting height detection device 40B. In particular, the action of the stalks 400 and the like on the grounding body 42 may reduce the accuracy of the detection of the cutting height by the sensor unit 45.

[0180] Therefore, by providing the culm guide 300 on the second conveying passage 322 side of the cutting height detection device 40B supported on the grass dividing frame 34, the culm can be guided so that the movement path of the culm in the second conveying passage 322 is a movement path in which the culm passes outside the cutting height detection device 40B and avoids the cutting height detection device 40B, that is, the culm moves away from the cutting height detection device 40B. This makes it possible to prevent the culm from contacting the culm 400, and to protect the cutting height detection device 40B from the culm that has entered the second conveying passage 322. As a result, it is possible to ensure the detection accuracy of the cutting height by the cutting height detection device 40B, and to prevent damage to the cutting height detection device 40B due to contact by the culm.

[0181] In addition, the culm guide 300 is provided so as to protrude to the right side of the cutting height detection device 40B in a plan view. With this configuration, the culms passing through the second conveying passage 322 can be reliably kept away from the cutting height detection device 40B, and the contact of the culms with the cutting height detection device 40B can be effectively suppressed. This makes it possible to prevent damage to the cutting height detection device 40B and improve the detection accuracy of the cutting height. In addition, since the culm guide 300 can be disposed so as to substantially cross the lower part of the second conveying passage 322, it is possible to encourage the upright position of the culms that have fallen during reaping, and to reduce the contact of the culms with the cutting height detection device 40.

[0182] In addition, the grass dividing frame 34 has a bent portion 110, the cutting height detection device 40B is disposed in the space portion 100 formed by the bent portion 110, and the first front culm guide 301 and the second front culm guide 302 are provided in a state supported by the front portion of the bent portion 110. According to this configuration, the cutting height detection device 40B can be protected by the frame portion forming the bent portion 110 in the grass dividing frame 34, so that the contact of the culms with the cutting height detection device 40B can be effectively suppressed, and the detection accuracy of the cutting height can be improved and damage to the cutting height detection device 40B can be suppressed. In addition, since the grass dividing frame 34 can be used as a configuration for supporting the culm guide 300, the support configuration of the culm guide 300 can be simplified.

[0183] Furthermore, by supporting the front ends of the first front culm guide 301 and the second front culm guide 302 at the front of the bent portion 110, these culm guides 300 can be positioned at an appropriate height relative to the cutting height detection device 40B with a simple configuration, and the cutting height detection device 40B can be effectively protected from the culms. Furthermore, since the support parts of the first front culm guide 301 and the second front culm guide 302 can be positioned immediately behind the grass dividing board 21, the support parts of these culm guides 300 can be protected from the culms.

[0184] In addition, a connecting plate 140 is provided between the front inclined frame part 102 and the rear inclined frame part 103 which form the bent part 110 in the grass dividing frame 34, and the cutting height detection device 40B is provided in a state supported by the connecting plate 140. According to this configuration, the connecting plate 140 can reinforce the portion of the grass dividing frame 34 where the bent part 110 is formed, and the cutting height detection device 40B can be firmly supported.

[0185] The combine harvester 1 also has, as the culm guides 300, a first front culm guide 301 and a second front culm guide 302 supported at the front part of the bending part 110, and an auxiliary culm guide 303 supported at the connecting plate 140. With this configuration, it is possible to efficiently arrange and support a plurality of culm guides 300 in the reaping unit 5. This makes it possible to strengthen the frame configuration of the reaping unit 5 and to realize a simple configuration for the reaping unit 5.

[0186] In addition, by supporting the front end of the auxiliary culm guide 303 on the connecting plate 140 located inside the bent portion 110, the auxiliary culm guide 303 can be positioned at an appropriate height relative to the cutting height detection device 40B with a simple structure, and the cutting height detection device 40B can be effectively protected from the culms. In addition, the support portion of the auxiliary culm guide 303 can be protected from the culms by the frame portion that forms the bent portion 110 in the grass dividing frame 34.

[0187] Additionally, the combine harvester 1 has a configuration in which the mowing height adjustment dial 202 and the automatic mowing height switch 205 are disposed on the side panel portion 151L on the side of the handle portion 15 in the driver's section 14. With this configuration, the operator seated in the driver's seat 16 can operate the mowing height adjustment dial 202 and the automatic mowing height switch 205 while facing forward during mowing work. This improves the operability of the mowing height adjustment dial 202 and the automatic mowing height switch 205 during mowing work, and provides good operability.

[0188] The above-described embodiment is an example of the present invention, and the present invention is not limited to the above-described embodiment. Therefore, even if it is not the above-described embodiment, various modifications are possible according to the design, etc., as long as they do not deviate from the technical idea of ​​the present invention. In addition, the effects described in this disclosure are merely examples and are not limited, and other effects may be present.

[0189] In the above-described embodiment, the combine harvester 1 is provided with three culm guides 300, but may be provided with only one culm guide 300 or with four or more culm guides 300. The shape of the culm guide 300 is not limited to the above-described embodiment, and may be any shape that can guide the culm away from the cutting height detection device 40 disposed behind the raising device 22. [Explanation of symbols]

[0190] 1. Combine Harvester 4 Running body 5 Reaping section 20 Harvesting support machine frame 22 Lifting device 34 minutes grass frame 40 Cutting height detection device 40B Cutting height detection device 100 Space 102 Front inclined frame portion (first frame portion) 103 Rear inclined frame part (second frame part) 110 Bend 140 Connecting plate (intervening member) 300 Grain Culm Guide 301 First culm guide (First culm guide) 302 Second front culm guide (first culm guide) 303 Auxiliary culm guide (second culm guide) 310 Support Plate 322 Second conveying passage

Claims

1. A combine harvester comprising a reaping unit having a lifting device and connected to a traveling machine body so as to be liftable and lowerable, and a cutting height detection device for detecting the height of the reaping unit, The cutting height detection device is provided at a position behind the lifting device in a state where it is supported by a grass division frame constituting the frame of the reaping unit, and one or more culm guides for guiding the culms are provided on the culm conveying passage side in the left-right direction relative to the cutting height detection device and above the cutting height detection device in the up-down direction. A combine harvester characterized by the above.

2. The stalk guide is provided so as to extend to the side of the cutting height detection device in a plan view. The combine harvester according to claim 1 .

3. The grass division frame has a bent portion bent upward in a mountain shape at a position rearward of the lower part of the lifting device, the cutting height detection device is provided in a space defined by the bent portion, The stalk guide is supported at the front of the bent portion. The combine harvester according to claim 1 or 2.

4. The grass frame has a first frame portion and a second frame portion that form the bent portion, an interposition member is provided between the first frame portion and the second frame portion and is fixed to at least one of the first frame portion and the second frame portion; The cutting height detection device is supported by the intermediate member. The combine harvester according to claim 3 .

5. As the grain stalk guide, A first stalk guide supported at a front portion of the bent portion; A second stalk guide supported by the intermediate member. The combine harvester according to claim 4 .

Images