Work vehicles

Abstract

To enable a support structure of track rollers to be excellently attached to and detached from a truck frame and to obtain sufficient strength, in a crawler part of a running device of a work vehicle.SOLUTION: A work vehicle is equipped with a crawler-type running device having a pair of left and right crawler parts. The crawler part has: a truck frame 100 having first side plates 112 forming left and right side surface portions, where lower sides of the left and right side surface portions are opened; a pair of track rollers 103 positioned at both left and right sides of the truck frame 100 in a lateral direction; and a track roller mounting members 150 supporting the pair of track rollers 103 with respect to the truck frame 100. The track roller mounting member 150 includes track roller supporting parts 151 and 251 supporting the pair of track rollers 103 on both left and right sides and mounting bracket parts 152 and 252, provided above the track roller supporting parts 151 and 251, positioned between the left and right side surface parts, and receiving fixation of the truck frame 100.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a work vehicle equipped with a crawler-type traveling device. [Background technology]

[0002] Conventionally, as a traveling device equipped on a work vehicle such as a combine harvester, there is a crawler type traveling device having a pair of left and right crawler parts. Regarding the crawler part of such a traveling device, there is a configuration in which multiple rollers are supported on a track frame extending in the front-rear direction (for example, see Patent Document 1). For example, the crawler part has a configuration in which a driving wheel is arranged on one front-rear side of the multiple rollers and a driven wheel is arranged on the other front-rear side, and a crawler belt, which is an endless track, is wound around these wheels.

[0003] Patent Document 1 discloses a configuration in which a track roller shaft, which is rotatably supported within an axle cylinder, has rollers supported at both ends, and the rollers are attached to a track frame via a pair of plate-shaped supports, one on each side, which are integral with the axle cylinder. The track frame receives the axle cylinder from the open lower side, which is an approximately inverted U-shaped cross section. The supports, which are provided on the upper side of the axle cylinder, are detachably fastened to the left and right side walls of the track frame by bolts. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 52-132533 Summary of the Invention [Problem to be solved by the invention]

[0005] In the configuration disclosed in Patent Document 1, a plate-shaped support base is placed on the inside of each of the left and right side walls of a truck frame having a cross section shaped like an inverted U, and the support base is fastened to the truck frame by bolts that penetrate the side walls and the support base. With such a configuration, it is difficult to obtain sufficient strength for the crawler unit as a support structure for the rollers, and there is a problem that the truck frame may be deformed in some cases.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a work vehicle in which the support structure for the rollers in the crawler section of the running gear can be easily attached and detached from the track frame while also having sufficient strength. [Means for solving the problem]

[0007] The work vehicle of the present invention is a work vehicle equipped with a crawler-type running device having a pair of left and right crawler sections, the crawler sections having left and right side portions with the lower sides of the left and right side portions open, a pair of rollers located on both the left and right sides of the truck frame in the left-right direction, and a roller mounting member that supports the pair of rollers to the truck frame, the roller mounting member including a roller support portion that supports the pair of rollers on both the left and right sides, and a mounting bracket portion provided above the roller support portion, located between the left and right side portions, and receiving the fixation of the truck frame.

[0008] The work vehicle of the present invention is a work vehicle in which the crawler section further has a crawler guide located between the pair of rollers in the left-right direction and guiding the crawler belt, and the crawler guide includes a crawler guide main body portion that acts on the crawler belt, and an attachment portion provided on the upper side of the crawler guide main body portion, located between the left and right side portions, and receiving the fixation of the track frame.

[0009] In a work vehicle according to the present invention, a fixing portion of the crawler guide to the track frame is located lower than a fixing portion of the roller mounting member to the track frame.

[0010] In the work vehicle of the present invention, the roller mounting members are arranged at intervals in the extension direction of the track frame, and the fixing portion of the crawler guide relative to the track frame is located between adjacent roller mounting members. Effect of the Invention

[0011] According to the present invention, in the crawler portion of the traveling device, the support structure for the rollers can be easily attached to and detached from the track frame, and sufficient strength can be obtained. [Brief description of the drawings]

[0012] [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. 1 is a plan view of a combine harvester according to one embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing a power transmission configuration in a combine harvester according to one embodiment of the present invention. [Diagram 5] FIG. 2 is a left side view showing the configuration of a traveling device according to an embodiment of the present invention. [Figure 6] FIG. 2 is a front perspective view showing a configuration of a portion of a crawler unit according to an embodiment of the present invention. [Figure 7] 4 is a left side view showing the configuration of a front part of the crawler unit according to the embodiment of the present invention. FIG. [Figure 8] FIG. 4 is a left side view showing the attachment state of a roller attachment member and a crawler guide in the crawler section according to one embodiment of the present invention. [Figure 9] FIG. 2 is a front cross-sectional view of the crawler unit according to the embodiment of the present invention. [Figure 10] FIG. 2 is a front cross-sectional view of the crawler unit according to the embodiment of the present invention. [Figure 11] FIG. 2 is a perspective view showing a roller mounting member according to one embodiment of the present invention. [Figure 12] FIG. 2 is a perspective view showing a roller mounting member according to one embodiment of the present invention. [Figure 13] FIG. 1 is a perspective view showing a crawler guide according to an embodiment of the present invention. [Figure 14] FIG. 2 is a left side view showing the crawler guide according to the embodiment of the present invention. [Figure 15] FIG. 2 is a front cross-sectional view of the crawler unit according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present invention aims to improve the support strength of the rollers while maintaining ease of maintenance by devising a support structure for the rollers in a configuration equipped with a crawler-type traveling device having a pair of left and right crawler parts. Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] In the following embodiment of the present invention, a combine harvester will be taken as an example of the work vehicle according to the present invention. However, the present invention can be applied to various types of combine harvesters, such as head-feeding combine harvesters and normal combine harvesters, as well as construction machines such as excavators and other types of work vehicles, such as tractors, so long as they are equipped with a crawler-type traveling device.

[0015] The overall configuration of the combine harvester 1 according to this embodiment will be described with reference to Figures 1 to 4. In the following description, the left side (lower side in Figure 3) and the right side (upper side in Figure 3) facing the front of the combine harvester 1 are the left side and the right side of the combine harvester 1, respectively.

[0016] As shown in Figures 1 and 2, the combine harvester 1 according to this embodiment is a normal type combine harvester that rakes in harvested crops (rice, wheat, soybeans, corn, etc.) from a field into the machine body, threshes, sorts, stores the grains, and can be transported outside the machine as needed. The combine harvester 1 has a self-propelled traveling body 2 and a reaping unit 3 provided at the front end of the traveling body 2. The reaping unit 3 is configured as a reaping device that harvests and collects unharvested stalks of rice, wheat, etc., and is attached to the traveling body 2 so as to be able to rise and fall.

[0017] The traveling machine body 2 is equipped with a crawler type traveling device 4 having a pair of left and right crawler units 5, 5. A machine body frame 6 is provided above and between the left and right crawler units 5, 5. Each crawler unit 5 has a drive sprocket 5a as a drive wheel provided at its front end. The drive sprocket 5a is rotated by receiving power transmitted from an engine 25 equipped in the combine harvester 1.

[0018] On the left side of the machine frame 6, there are provided a threshing section 7 which threshes the stalks cut and supplied by the reaping section 3, and a sorting section 8 which sorts the grains threshed by the threshing section 7. The threshing section 7 and the sorting section 8 are arranged with the threshing section 7 on the upper level and the sorting section 8 on the lower level.

[0019] On the machine frame 6, to the right of the threshing section 7 and the sorting section 8, there is provided a grain storage section 9 having a grain tank 10 for storing grains (clean grains) sorted in the sorting section 8. A lower discharge conveyor 11 for transporting the stored grains toward the discharge port of the grain tank 10 is provided in the grain tank 10 (see FIG. 4). A vertical transport conveyor 12 is provided upright in the vertical direction so as to communicate with the discharge port of the grain tank 10. A grain discharge conveyor 13 is connected to the upper end of the vertical transport conveyor 12. The grain discharge conveyor 13 is provided so as to be rotatable in the horizontal direction and to be swingable up and down around a horizontal axis. The grains in the grain tank 10 are transported by these conveyors, and are discharged from a paddy inlet 14 provided at the tip of the grain discharge conveyor 13 into a truck bed, a container, or the like.

[0020] A driver's section 15 covered by a cabin 16 is provided on the machine frame 6 in a position forward of the grain storage section 9, i.e., at a position on the right front side of the machine frame 6. The driver's section 15 is provided with a driver's seat, a steering wheel, and various operating tools such as a main speed change lever, a sub speed change lever, and a work clutch lever.

[0021] An engine 25 as a drive source is provided below the driver's unit 15 on the machine frame 6. The engine 25 is installed in the space below the driver's unit 15, in the space on the right side of the front part of the machine frame 6. The engine 25 is, for example, a diesel engine.

[0022] The reaping unit 3 has a feeder 30 as a transport device, a grain header (platform) 31, a cutting blade device 32, a pair of left and right grass dividing bodies 33, 33, and a raking reel .

[0023] The feeder 30 transports the stalks harvested by the harvesting section 3 and supplies them to the threshing section 7. The feeder 30 has a structure in which a conveyor 36 (see FIG. 4) is provided inside a feeder house 35 serving as a housing. The feeder 30 is provided with the rear end opening of the feeder house 35 communicating with the front handling port 7a of the threshing section 7. The grain header 31 is configured in a horizontally elongated bucket shape, and is connected to the front side of the feeder 30 so as to communicate with the front end opening of the feeder house 35. A raking auger (platform auger) 37 is provided inside the grain header 31 and is rotatably mounted with the left-right direction as the rotation axis direction.

[0024] The cutting blade device 32 is provided at the front lower edge of the grain header 31 and is configured like a clipper. A pair of left and right grass dividing bodies 33, 33 are provided so as to protrude forward from the left and right sides at the front of the grain header 31. The raking reel 34 is a reel with a tine bar, and is provided at a position above and in front of the raking auger 37 in a state where it is supported rotatably with the left and right direction as the rotation axis direction. The raking reel 34 acts continuously on the pod-bearing part of the culm while rotating, and rakes the pod-bearing part of the culm into the raking auger 37 side.

[0025] The conveyor 36 in the feeder house 35 has a reaping input shaft 38, which is provided in front of the threshing unit 7 and has an axial direction in the left-right direction, as a drive shaft supporting the feeding end side of the conveyor 36. The rear end of the feeder 30 is supported rotatably relative to the traveling machine body 2 side with the reaping input shaft 38 as a rotating shaft. A lifting cylinder 39, which is a hydraulic cylinder, is interposed between the underside of the feeder house 35 and the machine body frame 6. The extension and contraction of the lifting cylinder 39 causes the reaping unit 3 to rise and fall with the reaping input shaft 38 as a rotating shaft.

[0026] A front rotor 26 is provided on the rear side of the feeder 30 to send the stalks transported by the conveyor 36 to the threshing opening 7a. The front rotor 26 has a roughly cylindrical rotor body called a beater or the like, and a front rotor shaft 28 (see FIG. 4) whose axial direction is in the left-right direction. The stalks transported by the feeder 30 are fed from the end of the conveyor 36 by the front rotor 26 through the threshing opening 7a into the threshing chamber 7b.

[0027] The threshing section 7 has a threshing drum 40 provided in a threshing chamber 7b with a threshing port 7a opening to the front, and a receiving net 42 arranged below the threshing drum 40. The threshing chamber 7b is formed by a machine frame provided on the machine body frame 6. The threshing drum 40 is rotatably supported by a threshing drum shaft 41 (see FIG. 4) whose axial direction is the front-to-rear direction. The receiving net 42 allows grains to drop through, and is provided along the outer peripheral surface of the lower part of the threshing drum 40.

[0028] The sorting section 8 has a swaying sorting plate 43 as a swinging section arranged below the receiving net 42, a swinging mechanism 44 including a swinging shaft 44a that swings the swaying sorting plate 43, a first conveyor 45, a second conveyor 46, and a winnower 47 (see FIG. 4). As shown in FIG. 4, a pre-fan 71 is provided in front of the winnower 47, and a second fan 72 is provided behind the winnower 47.

[0029] The oscillating sorting plate 43 has a configuration for gravity sorting such as a feed pan, chaff sieve, or grain sieve. The first conveyor 45 is disposed in a first trough extending in the width direction of the machine body so as to collect the first grains. The second conveyor 46 is disposed in a second trough extending in the width direction of the machine body at a position rearward of the first conveyor 45 so as to collect the second grains. The winnower 47 blows sorting air from the front lower to the rear upper to the oscillating sorting plate 43.

[0030] A return conveyor 48 is provided on the right side of the machine body where the threshing section 7 and sorting section 8 are located (see FIG. 4). The return conveyor 48 is connected to the second conveyor 46 with its lower end located near the second conveyor 46, and its upper end located near the front end of the handling drum 40, extending in an upward sloping manner. On the right side of the return conveyor 48, a grain lifting conveyor 49 is provided extending vertically, for transporting the first grain sent by the first conveyor 45 into the grain tank 10.

[0031] The combine harvester 1 having the above-mentioned configuration raises the cutting section 3 to a desired height above the ground (cutting height of the culms, which are the harvested crop) in a field by raising and lowering the feeder 30 with the cutting input shaft 38 at the center (support shaft), changes from a non-working state to a working state, and travels in this state using the traveling body 2. As a result, the combine harvester 1 separates the harvested crop into cutting targets and non-cutting targets using the left and right dividing bodies 33, 33, and cuts the pod-bearing parts of the culms with the cutting blade device 32 while raking in the pod-bearing parts on the tip side of the culms to be cut with the raking reel 34.

[0032] The pod-bearing portions of the stalks harvested at the desired harvesting position are raked into the grain header 31 by the rotating raking auger 37 and collected near the entrance to the feeder house 35, then transported by conveyor 36 through the feeder house 35 and fed into the threshing opening 7a by the front rotor 26, and supplied to the threshing section 7.

[0033] The pod-bearing portions of the stalks supplied to the threshing section 7 are transported rearward by the rotating threshing drum 40 and threshed mainly between the threshing drum 40 and the receiving net 42. Grains and other threshed particles that are smaller than the mesh size of the receiving net 42 leak through the receiving net 42. Straw chips and other particles that do not leak through the receiving net 42 are discharged into the field from a dust outlet provided at the rear of the sorting section 8 by the transporting action of the threshing drum 40.

[0034] The threshed grain that falls through the receiving net 42 is sorted in the sorting section 8 by the gravity sorting action of the oscillating sorting plate 43 and the wind sorting action of the winnowing basket 47 into refined grains (first grains), a mixture of grains such as grains with stalks and straw (second grains), and straw chips, etc., and removed. The grains (first grains) that fall from the oscillating sorting plate 43 are transported to the grain tank 10 by the first conveyor 45 and the grain lifting conveyor 49 connected thereto. The second grains are returned to the threshing start end of the threshing drum 40 by the second conveyor 46 and the return conveyor 48 connected thereto, and are subjected to threshing again. The straw chips, etc. are discharged into the field from a dust outlet provided at the rear of the sorting section 8.

[0035] Next, the power transmission configuration of the combine harvester 1 according to this embodiment will be described with reference to Fig. 4. The combine harvester 1 drives the reaping unit 3, the traveling device 4, the threshing unit 7, the sorting unit 8, and the grain storage unit 9 by the rotational power of the engine 25.

[0036] The engine 25 has a first output shaft 25a and a second output shaft 25b. The rotational power of the first output shaft 25a is transmitted to the traveling device 4, the threshing section 7, the sorting section 8, and the reaping section 3. The rotational power of the second output shaft 25b is transmitted to the grain storage section 9. The engine 25 also has a work implement pump shaft that drives a charge pump 54 that operates the lifting cylinder 39 and the like.

[0037] With regard to the power transmission system to the traveling device 4, the rotational power of the first output shaft 25a is transmitted to the HST input shaft 52 by the first belt transmission mechanism 51, and is input to the transmission 53 including the traveling HST and the turning HST. Here, "HST" refers to a hydraulic continuously variable transmission that employs a system in which hydraulic pressure generated by driving a hydraulic pump is converted again into rotational power by a hydraulic motor. The driving force of the transmission 53 drives and rotates the driving sprockets 5a of the crawler unit 5 constituting the traveling device 4. The left and right driving sprockets 5a are fixed to driving shafts 5b protruding in the left and right directions from the transmission 53, respectively.

[0038] With regard to the power transmission system to the threshing unit 7, the rotational power of the first output shaft 25a is transmitted to the threshing unit input shaft 56 by a second belt transmission mechanism 55. The second belt transmission mechanism 55 is provided with a threshing clutch 57 that transmits the rotational power of the first output shaft 25a to the threshing unit input shaft 56 intermittently as desired. The rotational power of the threshing unit input shaft 56 is transmitted to the threshing drum input shaft 59 by a third belt transmission mechanism 58. The rotational power of the threshing drum input shaft 59 is transmitted to the threshing drum shaft 41 via a threshing speed change device 60 that changes the speed between two stages, for example, high speed and low speed.

[0039] With this configuration, the driving force of the engine 25 is transmitted to the threshing unit 7. Then, by operating the work clutch lever provided on the driving unit 15, the threshing clutch 57 is turned ON / OFF, and the power transmission to the threshing unit 7 is interrupted.

[0040] With regard to the power transmission system to the sorting section 8, the threshing section input shaft 56 has a support shaft portion for the winnowing machine 47, and the rotational power of the threshing section input shaft 56 is transmitted to a pulley rotor 63 journalled on a threshing intermediate shaft 62 by a fourth belt transmission mechanism 61. The rotational power of the pulley rotor 63 is transmitted to the pre-fan 71 and the winnowing machine 47 by a prescribed transmission mechanism. In addition, the rotational power of the threshing section input shaft 56 is transmitted to the respective rotational shafts of the first conveyor 45, the second fan 72 and the second conveyor 46 by a prescribed transmission mechanism.

[0041] The rotational power of the first conveyor 45 is transmitted to the lifting conveyor 49 by a predetermined transmission mechanism. The rotational power of the second conveyor 46 is transmitted to the swing shaft 44a of the swing mechanism 44 by a fifth belt transmission mechanism 64. The rotational power of the second conveyor 46 is transmitted to the return conveyor 48 via a bevel gear.

[0042] With regard to the power transmission system to the reaping unit 3, the rotational power of the pulley rotor 63 is transmitted to the front rotor shaft 28 of the front rotor 26 by a sixth belt transmission mechanism 73. The sixth belt transmission mechanism 73 is provided with a reaping clutch 75 that optionally transmits the rotational power of the pulley rotor 63 to the front rotor shaft 28 intermittently. The rotational power of the front rotor shaft 28 is transmitted to the reaping input shaft 38 by a first chain transmission mechanism 65. The conveyor 36 in the feeder house 35 is operated by the rotational drive of the reaping input shaft 38.

[0043] The rotational power of the cutting input shaft 38 is transmitted to a PF (platform) drive shaft 67 by a second chain transmission mechanism 66. The rotational power of the PF drive shaft 67 is transmitted via a third chain transmission mechanism 68 to a PF auger shaft 37a that rotates the raking auger 37. The rotational power of the PF drive shaft 67 is also transmitted via a seventh belt transmission mechanism 69 to a cutting blade drive shaft 32a that drives the cutting blade device 32. The rotational power of the PF drive shaft 67 is also transmitted to a reel shaft 34b that rotates the raking reel 34 by a fourth chain transmission mechanism 76 including a reel counter shaft 70.

[0044] With this configuration, the driving force of the engine 25 is transmitted to the cutting unit 3. Then, by operating a work clutch lever provided on the driving unit 15, the cutting clutch 75 is turned ON / OFF, and the power transmission to the cutting unit 3 is interrupted.

[0045] With regard to the power transmission system to the grain storage section 9, the rotational power of the second output shaft 25b is transmitted to the lower discharge conveyor 11 by a power transmission mechanism including a grain tank intermediate shaft 77, and the rotational power of the lower discharge conveyor 11 is transmitted to the vertical transport conveyor 12 via a bevel gear. The rotational power of the vertical transport conveyor 12 is transmitted to the grain discharge conveyor 13 by a predetermined transmission mechanism. The grain storage section 9 is equipped with a suction fan 78 and a compressor 79 as a configuration that receives the rotational power transmitted from the grain tank intermediate shaft 77 and drives them.

[0046] The traveling device 4 will be described with reference to Fig. 5 to Fig. 15. Fig. 9 is a cross-sectional view taken along line AA in Fig. 7, Fig. 10 is a cross-sectional view taken along line BB in Fig. 7, and Fig. 15 is a cross-sectional view taken along line CC in Fig. 7.

[0047] As described above, the traveling device 4 has a pair of left and right crawler units 5, 5. The left and right crawler units 5, 5 are configured symmetrically or approximately symmetrically in the left-right direction. For this reason, Fig. 5 to Fig. 15 show the configuration of the left crawler unit 5, and the left crawler unit 5 will basically be described.

[0048] The crawler unit 5 includes a drive sprocket 5a provided at its front end, a track frame 100, a tension wheel 101 provided at its rear end, an upper roller 102, a plurality of rollers 103, and a crawler belt 104 as a track. The drive sprocket 5a, the tension wheel 101, the upper roller 102, and the plurality of rollers 103 are all rotating bodies whose rotation axis is in the left-right direction.

[0049] The track frame 100 is a substantially horizontal and substantially linear frame portion extending in the front-rear direction, and constitutes the base of the crawler unit 5. The track frame 100 has a front frame portion 106 that forms the front portion of the track frame 100, and a rear frame portion 107 that forms the rear portion of the track frame 100. The rear frame portion 107 is connected to the rear end portion of the front frame portion 106, and the two frame portions form an integrated track frame 100.

[0050] The front frame section 106 has a main body frame 111 made of a square pipe-shaped member with both ends open, and a pair of first side plates 112 provided on both the left and right sides of the lower part of the main body frame 111. The main body frame 111 is a linear member having a rectangular cross section with the vertical direction as the longitudinal direction, and is provided horizontally with the extension direction as the front-rear direction. The main body frame 111 has an upper surface portion 111a, a lower surface portion 111b, and left and right side wall portions 111c as parts forming its cross section.

[0051] The left and right first side plates 112 are plate-like members whose thickness direction is in the left-right direction, have approximately the same length as the main body frame 111, and are provided over approximately the entire range of the main body frame 111 in the extension direction. The upper edge of the first side plate 112 is fixed from the outside to the lower edge of the side wall portion 111c of the main body frame 111 by welding or the like.

[0052] The first side plate 112 has a portion below an upper edge portion, which is a fixed portion to the main body frame 111, extending downward from a lower surface portion 111b of the main body frame 111. On the lower side of the main body frame 111, a front support space portion 113, which is a space with an open lower side, is formed by the side wall portions 111c and the left and right first side plates 112.

[0053] In the front frame portion 106, a reinforcing member 114 is provided on the upper side of the front part of the main body frame 111. The reinforcing member 114 is a channel steel member having a substantially "U" shaped cross section. The reinforcing member 114 has substantially the same width as the main body frame 111, and is fixed to the main body frame 111 by welding or the like, with the open side facing downward.

[0054] The rear frame portion 107 has left and right second side plates 116, an upper plate 117, and a middle plate 118 (see FIG. 5). The left and right second side plates 116, the upper plate 117, and the middle plate 118 have approximately the same length in the front-rear direction. The second side plate 116 is a plate-shaped member whose plate thickness direction is in the left-right direction, and is located on the rear side of the first side plate 112 and is provided so as to be approximately continuous with the first side plate 112. When the first side plate 112 is the front side plate, the second side plate 116 is the rear side plate. The front end of each second side plate 116 is fixed from the outside to the left and right side wall portions 111c at the rear end of the main body frame 111 by welding or the like.

[0055] The upper plate 117 has a shape that follows the upper edge of the second side plate 116, and is provided so as to close the upper side between the left and right second side plates 116. The middle plate 118 has approximately the same width as the upper plate 117, and is provided horizontally between the left and right second side plates 116 with the plate thickness direction being the up-down direction. The middle plate 118 is provided at a height position that is approximately the center of the second side plate 116 in the up-down direction in the up-down direction. The middle plate 118 is located at approximately the same height as the lower surface portion 111b of the main frame 111, and is provided so as to form a horizontal surface portion that is continuous and flush with the lower surface portion 111b. The upper plate 117 and the middle plate 118 are fixed to the left and right second side plates 116 by welding or the like.

[0056] The space between the left and right second side plates 116 is divided into upper and lower portions by the middle plate 118. In the rear frame portion 107, below the middle plate 118, a rear support space portion 119, which is a space with an open lower side, is formed by the middle plate 118 and the lower parts of the left and right second side plates 116.

[0057] 5 and 6, the truck frame 100 is connected and supported on both the front and rear sides to the vehicle frame 6 (see FIG. 1) by a front support frame portion 121 and a rear support frame portion 122. The front support frame portion 121 connects and supports the front end portion of the truck frame 100 to the vehicle frame 6, and the rear support frame portion 122 connects and supports the rear end portion of the truck frame 100 to the vehicle frame 6.

[0058] The front support frame portion 121 includes a front support arm 123 extending outward to the left and right from the vehicle frame 6, and a front connecting frame 124 that connects the truck frame 100 to the front support arm 123. The front support arm 123 is made of a square pipe-shaped member and is provided horizontally with its longitudinal direction aligned in the left-right direction.

[0059] The front connecting frame 124 is generally "L" shaped in front view, and its left and right outer and lower ends are fixed by welding or the like to the left and right inner side portions of the front end of the front frame portion 106. Also, the left and right inner and upper ends of the front connecting frame 124 are fixed by welding or the like to the left and right outer portions of the front support arms 123. A front guard plate 125 having a triangular shape in side view is provided on the rear side of the front connecting frame 124.

[0060] The rear support frame portion 122 includes a rear support arm 126 extending outwardly to the left and right from the vehicle frame 6, and a rear connecting frame 127 that connects the truck frame 100 to the rear support arm 126. The rear support arm 126 is made of a square pipe-shaped member and is provided horizontally with its longitudinal direction aligned in the left-right direction.

[0061] The rear connecting frame 127 is generally "L" shaped when viewed from the front, with its outer left and right portions serving as tensioning ring support frames 128 that support the tensioning rings 101. The tensioning ring support frame 128 is made of a square pipe-shaped member, and is fixed by welding or the like to the upper side of the rear end portion of the rear frame portion 107, with the left-right direction as the longitudinal direction.

[0062] The left and right inner upper ends of the rear connecting frame 127 are fixed by welding or the like to the left and right outer portions of the rear support arm 126. Front guard plates 129, 130 each having a triangular shape in a side view are provided on the front and rear sides of the rear connecting frame 127.

[0063] The drive sprocket 5a is provided at an upper front position of the front end portion of the track frame 100. A drive sprocket support stay 131 for supporting the drive sprocket 5a extends obliquely upward and forward from the lower portion of the front connecting frame 124.

[0064] The tensioning wheel 101 is provided on the rear side of the truck frame 100. The tensioning wheel 101 is rotatably supported between the rear ends of left and right tensioning wheel support shafts 132, 132 that penetrate the tensioning wheel support frame 128 in the front-rear direction. The tensioning wheel support shafts 132, 132 are supported by a position adjustment mechanism 134 so that their positions can be adjusted in the front-rear direction relative to the tensioning wheel support frame 128 via a cylindrical support tube 133 through which the tensioning wheel support shaft 132 is inserted.

[0065] The position of the tension ring 101 in the front-to-rear direction is adjusted by adjusting the position of the tension ring support shafts 132, 132 relative to the tension ring support frame 128. The position adjustment mechanism 134 has an adjustment shaft 134a extending forward from the tension ring support frame 128, and a support bracket 134b installed between the front ends of the tension ring support shafts 132, 132 and screw-engaged with the adjustment shaft 134a.

[0066] The position adjustment mechanism 134 moves the support bracket 134b in the front-rear direction by rotating the adjustment shaft 134a to drive a screw, and adjusts the front-rear position of the tension wheel 101 via the tension wheel support shafts 132, 132. A lock nut, an adjustment nut, etc. screwed onto the adjustment shaft 134a are provided on the portion of the adjustment shaft 134a that protrudes forward from the support bracket 134b. The tension of the crawler belt 104 is adjusted by adjusting the position of the tension wheel 101.

[0067] The upper roller 102 is located above the track frame 100, approximately in the center of the track frame 100 in the front-to-rear direction. The upper roller 102 is rotatably supported by a support stay 135 that extends upward from the right side of the rear end of the front frame portion 106. The upper roller 102 has a cylindrical shaft portion 102a whose central axis coincides with the rotation axis of the upper roller 102, and circular wheel portions 102b provided on both ends of the shaft portion 102a.

[0068] The rollers 103 are ground contact rollers located above the ground contact portion of the crawler belt 104, and are provided in a pair of left and right rollers supported coaxially. The crawler section 5 has six roller units 140, each including a pair of left and right rollers 103, for a total of 12 rollers 103. The roller units 140 are provided so that the pair of rollers 103 is located on both the left and right sides of the lower side of the track frame 100. The pair of rollers 103 are supported by the track frame 100 via roller mounting members 150 (150A, 150B).

[0069] That is, the wheel unit 140 includes a pair of wheels 103 and a wheel mounting member 150 that rotatably supports the pair of wheels 103 and is attached to the track frame 100, and constitutes an integrated unit that is detachable from the track frame 100. The wheel unit 140 is configured symmetrically in the left-right direction.

[0070] The six roller units 140 are arranged in a line in the front-rear direction at a substantially constant height on the underside of the track frame 100. In this embodiment, the crawler unit 5 has a front roller group 142, which is a roller group of six rollers 103 with three roller units 140 arranged on the front side, and a rear roller group 143, which is a roller group of six rollers 103 with three roller units 140 arranged on the rear side. The front roller group 142 and the rear roller group 143 are arranged with a larger gap between them than the gap between the front and rear rollers 103 in each roller group. In this embodiment, the gap between the front and rear rollers 103 in the rear roller group 143 is wider than the gap in the front roller group 142.

[0071] The crawler belt 104 is wound around the driving sprocket 5a, the tensioning wheel 101, the upper roller 102, and the multiple rollers 103 so as to surround these rotating bodies. In other words, the crawler belt 104 supports these rotating bodies on its inner peripheral surface side.

[0072] 9, the crawler belt 104 has a rubber crawler belt body 144 and multiple core metals 145 partially embedded in the crawler belt body 144. The multiple core metals 145 are arranged so as to be spaced apart in the circumferential direction of the crawler belt 104. The core metal 145 has a pair of left and right core metal projections 145a, and the tip sides of the core metal projections 145a protrude toward the inner periphery of the crawler belt body 144.

[0073] The pair of rollers 103 are provided as so-called outer rollers located on the left and right outer sides of the left and right core metal protrusions 145a. The upper roller 102 is provided as an outer roller with the left and right wheel parts 102b arranged on the left and right outer sides of the left and right core metal protrusions 145a. The tension wheel 101 is provided as an inner roller located between the left and right core metal protrusions 145a in the left-right direction.

[0074] As described above, the crawler unit 5 includes a track frame 100 having left and right side portions 112a, 116a with the lower sides of the left and right side portions 112a, 116a open, a pair of rollers 103 located on both the left and right sides of the track frame 100 in the left-right direction, and a roller mounting member 150 that supports the pair of rollers 103 relative to the track frame 100.

[0075] In this embodiment, the left and right side surface portions 112a, 116a of the truck frame 100 are portions formed by the left and right first side plates 112 or portions formed by the left and right second side plates 116. Specifically, in the front frame portion 106, the left and right first side plates 112, portions which form the front support space portion 113 together with the lower surface portion 111b of the main body frame 111, are the left and right side surface portions 112a. In the rear frame portion 107, the left and right second side plates 116, portions which form the rear support space portion 119 together with the middle plate 118 are the left and right side surface portions 116a (see FIG. 5).

[0076] The roller mounting member 150 will now be described. The crawler unit 5 has two types of roller mounting members 150: a first roller mounting member 150A constituting four roller units 140 arranged in the front-rear middle portion, and a second roller mounting member 150B constituting two roller units 140 arranged at the front and rear ends. The roller mounting member 150 is, for example, a one-piece casting cast from a specified metal material.

[0077] First, the first roller mounting member 150A will be described. As shown in Figures 8 and 11, the first roller mounting member 150A has a roller support portion 151 and a mounting bracket portion 152 provided on the upper side of the roller support portion 151. In a side view, the first roller mounting member 150A has an outline shape of a substantially inverted isosceles triangle with the roller support portion 151 located on the lower side as the apex. The first roller mounting member 150A is configured symmetrically or substantially symmetrically in each of the front-rear and left-right directions.

[0078] The wheel support part 151 is a cylindrical part with a central axis in the left-right direction, and is open on both the left and right sides. The wheel support part 151 supports a pair of wheels 103 on both the left and right sides. The wheel support part 151 forms support holes 153 for supporting the left and right wheels 103 on its inner circumferential surface.

[0079] The mounting bracket portion 152 has a shape in which a rib portion 155, which is a thick portion having a predetermined shape, is provided on a plate-shaped bracket main body portion 154 whose thickness direction is in the left-right direction. The mounting bracket portion 152 has, as the rib portion 155, an outer edge rib portion 155a formed on the outer edge of the mounting bracket portion 152 along the approximately isosceles triangular outer shape of the mounting bracket portion 152, and a plurality of intermediate rib portions 155b formed on both the left and right sides of the bracket main body portion 154.

[0080] The intermediate rib portion 155b is formed so as to form a protrusion portion with respect to the bracket main body portion 154. In this embodiment, the intermediate rib portion 155b is formed on each of both sides of the bracket main body portion 154, with three rib portions at the front, center, and rear so as to radiate upward with respect to the circular shape formed by the roller support portion 151 in a side view.

[0081] The mounting bracket portion 152 has boss portions 156 formed at the front and rear corners. The boss portion 156 is a cylindrical portion with the left-right direction as the central axis direction, and is open on both the left and right sides. The boss portion 156 is a portion through which a bolt 160, which is a fastener for supporting and fixing the first roller mounting member 150A between the left and right side portions 112a or between the left and right side portions 116a, passes. The boss portion 156 serves as a mounting seat for the first roller mounting member 150A relative to the truck frame 100.

[0082] The inner peripheral surface of the boss portion 156 forms a hole portion 157 for passing the bolt 160 therethrough. The boss portion 156 has opening end faces 156a of the hole portion 157, which are surfaces perpendicular to the left-right direction, on both the left and right sides. The boss portion 156 is provided as a portion having a smaller diameter than the wheel support portion 151.

[0083] Thus, the first roller attachment member 150A has a substantially triangular shape in side view with the roller support portion 151 and the front and rear boss portions 156 as corners. Of the three intermediate rib portions 155b at the front, center, and rear of the first roller attachment member 150A, the front and rear intermediate rib portions 155b are formed so as to connect between the outer peripheral surface portion of the roller support portion 151 and the outer peripheral surface portion of the boss portion 156, and the central intermediate rib portion 155b is formed so as to connect between the outer peripheral surface portion of the roller support portion 151 and the upper outer edge rib portion 155a.

[0084] Furthermore, in the first roller mounting member 150A, the mounting bracket portion 152 is formed in the center in the left-right direction with respect to the roller support portion 151. Therefore, the roller support portion 151 protrudes on both the left and right sides with respect to the mounting bracket portion 152, and cylindrical protruding portions are formed on both the left and right sides at the bottom of the first roller mounting member 150A.

[0085] In addition, in the first roller mounting member 150A, support protrusions 158 having horizontal abutment surfaces 158a are formed near the front and rear bosses 156 on the upper surface of the mounting bracket part 152. The support protrusions 158 are formed in a protruding shape on the upper surface of the mounting bracket part 152, and the abutment surfaces 158a are brought into contact with the lower surface part 111b of the main body frame 111 from below.

[0086] The mounting bracket portion 152 is located between the left and right side surface portions 112a or between the left and right side surface portions 116a, and serves as a portion that receives the fixing of the track frame 100. Specifically, as shown in Fig. 10, the first roller mounting member 150A is fixed to the track frame 100 by the bolts 160 with the abutment surface 158a in contact with the lower surface of the lower surface portion 111b and with the left and right opening end surfaces 156a of the boss portion 156 in contact with the inner surfaces of the side surface portions 112a or 116a, respectively.

[0087] The bolt 160 passes through holes and holes 157 formed in the left and right side surface parts 112a or the left and right side surface parts 116a from the left and right outer sides (right side in FIG. 10), and has a tip part protruding from the left and right inner side surface part 112a or the side surface part 116a (left side in FIG. 10) and is screwed into the nut 161. A washer 162, through which the bolt 160 passes, is interposed between the head part 160a of the bolt 160 and the left and right outer side surface part 112a or the side surface part 116a.

[0088] In this way, the first roller mounting member 150A is fastened to the track frame 100 at two locations, the front and rear, by the bolts 160 and the nuts 161. Note that the number and positions of the fixing parts of the first roller mounting member 150A to the track frame 100 are not limited to this embodiment.

[0089] In this embodiment, the first roller mounting member 150A constituting the frontmost roller unit 140 of the three roller units 140 of the rear roller group 143 has a fixing portion by the front boss portion 156 located at the rear end of the left and right first side plates 112, and a fixing portion by the rear boss portion 156 located at the front end of the left and right second side plates 116. In other words, the first roller mounting member 150A is provided in a manner that it is bridged between the front frame portion 106 and the rear frame portion 107.

[0090] The support structure of the roller 103 relative to the roller mounting member 150 will be described. As shown in Fig. 9, the roller 103 has a rotating body shape with the rotation axis as the central axis, and includes a substantially disk-shaped support surface portion 171 that serves as a fixed support portion for the roller mounting member 150, and a substantially cylindrical peripheral wall portion 172 that serves as an acting portion for the crawler belt 104.

[0091] The roller 103 has a support surface portion 171 positioned on the left and right inner side, and a peripheral wall portion 172 is formed on the left and right outer sides from the peripheral edge of the support surface portion 171. The roller 103 has a bowl shape with the left and right inner sides as the bottom side and the left and right outer sides as the open sides due to the support surface portion 171 and the peripheral wall portion 172. The outer peripheral surface 172a of the peripheral wall portion 172 becomes the contact surface with the crawler belt 104.

[0092] As shown in Figure 9, the pair of left and right rollers 103 are connected to each other by a roller support shaft 180 that passes through the roller support part 151 of the first roller mounting member 150A, and together with the roller support shaft 180, form an integrated rotating body. The roller support shaft 180 has its axial direction in the left-right direction and is arranged coaxially with the support hole part 153 of the roller support part 151. The roller support shaft 180 is rotatably supported by the roller support part 151 via bearings 181 provided on both the left and right sides. The bearings 181 pass through the roller support shaft 180 and support the roller support shaft 180 against the inner circumferential surface of the support hole part 153.

[0093] The roller 103 has a boss portion 173 at the center of the support surface portion 171, into which the roller support shaft 180 is inserted. The boss portion 173 is formed to protrude inwardly to the left and right from the support surface portion 171 so as to form a cylindrical shape. Also, at the center of the support surface portion 171, a recess portion 174 forming a cylindrical inner circumferential surface is formed around the boss portion 173. The recess portion 174, together with the outer circumferential surface of the boss portion 173, forms an annular groove portion.

[0094] The portion of the roller support shaft 180 that is outside the portions supported by the bearings 181 on both the left and right sides is inserted into the boss portion 173, and the left and right ends protrude outward to the left and right from the support surface portion 171. The left and right ends of the roller support shaft 180 that protrude from the support surface portion 171 form reduced-diameter male threads. The roller support shaft 180 is fixed to each roller 103 by nut members 185 as fasteners that screw into the male threads at both ends.

[0095] The support surface of the roller support shaft 180 against the boss portion 173 has a tapered shape that gradually reduces in diameter from the left and right inner side to the left and right outer side, restricting the left and right outward movement of the roller support shaft 180 against the boss portion 173. In addition, a washer 186 is interposed between the nut member 185 and the support surface portion 171, through which the roller support shaft 180 passes.

[0096] The left and right open ends of the roller support part 151 are inserted into recesses 174 of the roller 103, and the boss part 173 is located within the left and right ends of the roller support part 151. The space between the open end of the roller support part 151 and the boss part 173 is sealed by an annular oil seal 187. The oil seal 187 is located within the recess 174 with the boss part 173 inserted and fitted into the opening of the roller support part 151.

[0097] The inside of the roller support part 151 is filled with lubricating oil. Inside the roller support shaft 180, oil passages (not shown) are formed that open into the internal space of the roller support part 151 and also open to the left and right outer end faces, and grease nipples 188 are attached to the left and right outer ends of the roller support shaft 180. The grease nipples 188 communicate with the oil passages inside the roller support shaft 180, and are used to supply lubricating oil to the inside of the roller support part 151.

[0098] Next, the second roller mounting member 150B will be described. As shown in Figures 8 and 12, the second roller mounting member 150B has a roller support part 251, and a mounting bracket part 252 and a fixed wall part 259 provided on the upper side of the roller support part 251. The second roller mounting member 150B is configured symmetrically or approximately symmetrically in the left-right direction.

[0099] The second roller mounting members 150B provided at the front and rear ends of the track frame 100 are attached to the track frame 100 so as to face in opposite directions in the front-to-rear direction. The mounting structures of the front and rear second roller mounting members 150B to the track frame 100 are symmetrical or approximately symmetrical to each other in the front-to-rear direction.

[0100] The wheel support part 251 is a cylindrical part with a central axis in the left-right direction, and is open on both the left and right sides. The wheel support part 251 supports a pair of wheels 103 on both the left and right sides. The wheel support part 251 forms support holes 253 for supporting the left and right wheels 103 on its inner circumferential surface.

[0101] The mounting bracket portion 252 has an outer shape of a substantially right-angled triangle with the upper side and the fixed wall portion 259 side being a right angle portion in a side view. The mounting bracket portion 252 has a shape in which a rib portion 255, which is a thick portion having a predetermined shape, is provided on a plate-shaped bracket main body portion 254 with the plate thickness direction being in the left-right direction. The mounting bracket portion 252 has, as the rib portion 255, an outer edge rib portion 255a formed on the outer edge of the mounting bracket portion 252 and an intermediate rib portion 255b formed on both the left and right sides of the bracket main body portion 254. The intermediate rib portion 255b forms a protrusion portion with respect to the bracket main body portion 254 and is formed so as to connect between the outer circumferential surface portion of the roller support portion 251 and the upper outer edge rib portion 255a.

[0102] The mounting bracket portion 252 has a boss portion 256 formed on the upper side and at a corner opposite to the fixed wall portion 259. In the second roller mounting member 150B mounted on the front side of the track frame 100, the boss portion 256 is located at the rear upper corner, and in the second roller mounting member 150B mounted on the rear side of the track frame 100, the boss portion 256 is located at the front upper corner. The boss portion 256 is a cylindrical portion with the left-right direction as the central axis direction, and is open on both the left and right sides. The boss portion 256 is a portion through which the bolt 160, which is a fastener for supporting and fixing the second roller mounting member 150B between the left and right side portions 112a or between the left and right side portions 116a, passes. The boss portion 256 becomes a mounting seat for the second roller mounting member 150B to the track frame 100.

[0103] The inner peripheral surface of the boss portion 256 forms a hole portion 257 for passing the bolt 160 therethrough. The boss portion 256 has opening end faces 256a of the hole portion 257, which are surfaces perpendicular to the left-right direction, on both the left and right sides. The boss portion 256 is provided as a portion having a smaller diameter than the wheel support portion 251.

[0104] The fixed wall portion 259 has a plate-shaped wall main body portion 261 whose thickness direction is in the front-rear direction, and a bracket portion 262 which is provided on the opposite side of the wall main body portion 261 to the mounting bracket portion 252 side and forms a thick portion. The fixed wall portion 259 is erected on the wheel support portion 251 so that the wall main body portion 261 is positioned in the front-rear center on the wheel support portion 251 and is vertical. The fixed wall portion 259 forms a vertical wall surface on the mounting bracket portion 252 side of the wall main body portion 261. The wall main body portion 261 and the upper surface portion of the mounting bracket portion 252 form an L-shaped surface portion that follows the right angle portion in a side view.

[0105] In addition, in the second roller mounting member 150B, the mounting bracket portion 252 and the fixed wall portion 259 are formed in the center in the left-right direction with respect to the roller support portion 251. Therefore, the roller support portion 251 protrudes on both the left and right sides relative to the mounting bracket portion 252 and the fixed wall portion 259, forming cylindrical protruding portions on both the left and right sides at the bottom of the second roller mounting member 150B.

[0106] In addition, in the second roller mounting member 150B, a support protrusion 258 having a horizontal abutment surface 258a is formed near the boss portion 256 on the upper surface of the mounting bracket portion 252. The support protrusion 258 is formed in a protruding shape on the upper surface of the mounting bracket portion 252, and the abutment surface 258a contacts the lower surface portion 111b of the main body frame 111 from below.

[0107] The mounting bracket portion 252, like the mounting bracket portion 152 of the first roller mounting member 150A, is located between the left and right side surface portions 112a or between the left and right side surface portions 116a, and serves as a portion that receives the fixing of the track frame 100. That is, the second roller mounting member 150B is fastened and fixed to the track frame 100 by the bolts 160 and nuts 161 with the abutment surface 258a in contact with the underside of the lower surface portion 111b and with the left and right opening end faces 256a of the boss portion 256 in contact with the inner surfaces of the side surface portion 112a or the side surface portion 116a, respectively.

[0108] The second roller mounting member 150B has the fixed wall portion 259 fixed to the front and rear end surfaces of the track frame 100 via a mounting plate 280. The mounting plate 280 is a vertical plate-like member with the plate thickness direction being in the front-rear direction, and is provided at the front end of the track frame 100 so as to close the space between the left and right first side plates 112, the front opening of the main frame 111, and the front opening of the reinforcing member 114 from the front side. The mounting plate 280 is fixed to the track frame 100 by welding or the like. At the rear end of the track frame 100, the mounting plate 280 is provided so as to close the space between the left and right second side plates 116 from the rear side.

[0109] The mounting plate 280 has support protrusions 281 that protrude on both the left and right sides at the vertical middle portion. The second roller mounting member 150B fastens the fixed wall portion 259 to the mounting plate 280 at two left and right locations by a bolt 283 that passes through the upper portion of the wall main body portion 261 and the support protrusions 281 and a nut 284 that receives the screw engagement of the bolt 283. Holes 261a through which the bolts 283 pass are formed on both the left and right sides of the upper portion of the wall main body portion 261.

[0110] As described above, the second roller mounting member 150B is fastened and fixed to the track frame 100 at two locations: a fixing portion by the bolt 160 that passes through the boss portion 256 in the left-right direction, and a fixing portion by the bolt 283 that passes through the fixing wall portion 259 in the front-rear direction. Note that the number and positions of the fixing portions of the second roller mounting member 150B to the track frame 100 are not limited to those in this embodiment.

[0111] The support structure of the roller 103 relative to the second roller mounting member 150B is the same as the support structure of the roller 103 relative to the first roller mounting member 150A. That is, the roller support shaft 180 that connects the left and right rollers 103 to each other is supported by the support hole 253 of the roller support part 251 via the left and right bearings 181, and both left and right ends of the roller support part 251 are sealed by oil seals 187 (see FIG. 9).

[0112] 5 and 8, the crawler unit 5 has a crawler guide 300 that is located between a pair of rollers 103 in the left-right direction and guides the crawler belt 104. The crawler guide 300 guides the crawler belt 104 relative to the track frame 100 so that the engagement state of the crawler belt 104 with the rollers 103 is maintained.

[0113] The crawler guides 300 are provided for each of the front roller group 142 and the rear roller group 143 on the underside of the track frame 100. That is, the crawler section 5 has two crawler guides 300: a front crawler guide 300 provided for the front three roller units 140, and a rear crawler guide 300 provided for the rear three roller units 140.

[0114] The front and rear crawler guides 300 have the same basic configuration, except that their front-to-rear lengths are different from each other in accordance with the intervals between adjacent wheels 103 in each of the front roller group 142 and the rear roller group 143. Therefore, the following mainly describes the front crawler guide 300. Figures 13 and 14 show the front crawler guide 300.

[0115] The crawler guide 300 includes a crawler guide main body 310 that acts on the crawler belt 104, and an attachment portion 320 that is provided on the upper side of the crawler guide main body 310, is located between the left and right side portions 112a or between the left and right side portions 116a, and receives the fixed track frame 100. The crawler guide 300 has the attachment portions 320 in two locations, one at the front and one at the rear. The crawler guide 300 is, for example, an integrated casting cast from a predetermined metal material.

[0116] The crawler guide 300 is configured symmetrically or approximately symmetrically in the front-rear direction, with the attachment parts 320 positioned in front of and behind the central position, with the center being the axis of the second-from-front roller 103 of the front roller group 142, which is located in the front-rear center. The crawler guide 300 is also configured symmetrically or approximately symmetrically in the left-right direction.

[0117] The crawler guide body 310 is a bar-shaped portion extending in the front-rear direction. The crawler guide body 310 is a narrow plate-shaped portion, and has a gently wavy curved shape in a side view.

[0118] The crawler guide main body 310 has a front curved surface portion 311, a central curved surface portion 312, and a rear curved surface portion 313 that follow the circumferential shape of the roller 103 in a side view at the front end, the front / rear central portion, and the rear end. These curved surfaces are curved surfaces with a convex lower side in a side view, and the lower end surface approximately coincides with the lower end of the roller 103. The front curved surface portion 311 and the rear curved surface portion 313 give the crawler guide main body 310 a shape in which the front and rear ends are warped upward.

[0119] In the crawler guide 300, a lower surface 310a of the crawler guide main body 310 serves as a contact surface for contacting the inner peripheral surface of the crawler belt 104. The crawler guide main body 310 is located between the left and right core metal projections 145a in the left-right direction with respect to the crawler belt 104, and the lower surface 310a is brought into contact with the inner peripheral surface of the crawler belt main body 144.

[0120] The mounting portion 320 has outer slopes 321 provided on the front and rear outer sides and inner slopes 322 provided on the front and rear inner sides, and these slopes form a substantially isosceles triangular shape in side view with the crawler guide main body 310 as the base. A boss portion 323 is provided at the upper end of the mounting portion 320, that is, at the apex of the substantially isosceles triangular shape in side view.

[0121] The boss portion 323 is a cylindrical portion with a central axis extending in the left-right direction, and is open on both the left and right sides. The boss portion 323 is a portion through which a bolt 330, which is a fastener for supporting and fixing the crawler guide 300 between the left and right side surface portions 112a or between the left and right side surface portions 116a, passes. The boss portion 323 serves as a mounting seat for the crawler guide 300 to the track frame 100.

[0122] The boss portion 323 has an inner peripheral surface portion that forms a hole portion 324 for passing the bolt 330 therethrough. The boss portion 323 has opening end faces 323a of the hole portion 324, which are surfaces perpendicular to the left-right direction, on both the left and right sides. The boss portion 323 has a dimension longer than the width dimensions of the outer inclined surface portion 321 and the inner oblique side portion 322 in the axial direction, and the left and right sides protrude relative to the front and rear oblique sides, forming cylindrical protruding portions on both the left and right sides at the upper end portion of the mounting portion 320.

[0123] Furthermore, the mounting portion 320 has a vertical surface portion 325 that is disposed between the boss portion 323 and the crawler guide main body portion 310, between the outer inclined surface portion 321 and the inner inclined side portion 322 in the front-rear direction. The vertical surface portion 325 is a vertical plate-like portion whose plate thickness direction is the front-rear direction, and is disposed so as to hang down from the lower end of the boss portion 323.

[0124] On both the front and rear sides of the outer inclined surface portion 321, reinforcing rib portions 326 are formed between the outer inclined surface portion 321 and the upper surface portion of the crawler guide main body portion 310. The rib portions 326 are plate-shaped portions whose thickness direction is in the left-right direction. The lower ends of the inner oblique side portions 322 of the front and rear mounting portions 320 are connected to each other by a horizontal flat portion 327 that is continuously formed with the same width as the inner oblique side portion 322.

[0125] A reinforcing intermediate rib portion 328 is formed between the front and rear inner oblique sides 322 and the upper surface of the crawler guide main body 310 below the flat surface portion 327. The intermediate rib portion 328 has a plate-shaped portion 328a whose thickness direction is in the left-right direction, and protrusions 328b formed on both the left and right sides of the plate-shaped portion 328a. The protrusions 328b are formed at two locations, one at the front and one at the back, on each of both sides of the plate-shaped portion 328a.

[0126] In the crawler guide 300, the attachment portion 320 is located between the left and right side surface portions 112a or between the left and right side surface portions 116a, and serves as a portion that receives the fixing of the track frame 100. Specifically, as shown in Fig. 15, the crawler guide 300 is fixed to the track frame 100 by bolts 330 with the left and right opening end faces 323a of the boss portion 323 in contact with the inner surfaces of the side surface portions 112a or 116a, respectively.

[0127] The bolt 330 passes through holes and holes 324 formed in the left and right side surface parts 112a or the left and right side surface parts 116a from the left and right outer sides (right side in FIG. 15), and has a tip part protruding from the left and right inner side surface part 112a or the side surface part 116a (left side in FIG. 15) and is screwed into the nut 331. A washer 332, through which the bolt 330 passes, is interposed between the head part 330a of the bolt 330 and the left and right outer side surface part 112a or the side surface part 116a.

[0128] In this manner, the crawler guide 300 is fastened to the track frame 100 at two locations, the front and rear, by the bolts 330 and the nuts 331. Note that the number and positions of the fixing portions of the crawler guide 300 to the track frame 100 are not limited to those in this embodiment.

[0129] The crawler guide 300 attached to the track frame 100 as described above guides the crawler belt 104 by positioning the crawler guide body 310 between the left and right core metal projections 145a. The crawler guide 300 maintains the working state of the rollers 103 relative to the crawler belt 104.

[0130] In the crawler unit 5 having the above-described configuration, the positional relationship between the guide fixing portion 410, which is the fixing portion of the crawler guide 300 to the track frame 100, and the mounting member fixing portion 420, which is the fixing portion of the roller mounting member 150 to the track frame 100, will be explained.

[0131] The guide fixing portion 410 is a portion where the crawler guide 300 is fastened to the track frame 100 by a bolt 330 or the like. The mounting member fixing portion 420 is a portion where the roller mounting member 150 is fastened to the track frame 100 by a bolt 160 or the like.

[0132] The guide fixing part 410 is located below the mounting member fixing part 420. In detail, as shown in Fig. 15, the bolt 330 constituting the guide fixing part 410 is located below the bolt 160 constituting the mounting member fixing part 420 in the up-down direction. That is, the axis C1 of the bolt 330 of the guide fixing part 410 is located below the axis C2 of the bolt 160 of the mounting member fixing part 420. Note that these axis lines are all aligned in the left-right direction and are parallel to each other.

[0133] In this embodiment, the entirety of bolt 330 is located below bolt 160. That is, with respect to the head, which is an enlarged diameter portion of the axially threaded portion of the bolt, the upper end of head 330a of bolt 330 is located lower in the up-down direction than the lower end of head 160a of bolt 160. The lengths of both bolts 160, 330 are approximately the same, and the positions of heads 160a, 330a of both bolts 160, 330 are approximately aligned with each other in the left-right direction.

[0134] Also, the guide fixing part 410 is located above the wheel support shaft 180 that supports the wheel 103. That is, in the up-down direction, the bolt 330 of the guide fixing part 410 is located above the wheel support shaft 180. Therefore, the axis C1 of the bolt 330 is located at a height above the axis C3 of the wheel support shaft 180 that is along the left-right direction.

[0135] In addition, in each of the front roller group 142 and the rear roller group 143, the roller mounting members 150 are arranged at intervals in the front-rear direction, which is the extension direction of the track frame 100. Specifically, in the front roller group 142, three roller mounting members 150, the second roller mounting member 150B, the first roller mounting member 150A, and the first roller mounting member 150A, are provided at predetermined intervals from the front to the rear (see FIG. 8). In the rear roller group 143, three roller mounting members 150, the first roller mounting member 150A, the first roller mounting member 150A, and the second roller mounting member 150B, are provided at predetermined intervals from the front to the rear.

[0136] In such an arrangement of the roller mounting members 150, the guide fixing portion 410 is located between adjacent roller mounting members 150 in the front-to-rear direction in each of the front roller group 142 and the rear roller group 143.

[0137] As shown in Figures 7 and 8, the second roller mounting member 150B and the first roller mounting member 150A, which are adjacent to each other in the front-rear direction, are arranged in close proximity to each other in the front-rear direction so that the mounting member fixing parts 420, which are fixed by bolts 160 located at the rear end of the second roller mounting member 150B and the front end of the first roller mounting member 150A, are lined up side by side in a side view. The height positions of these mounting member fixing parts 420 are the same or approximately the same. For the mounting member fixing parts 420 adjacent to each other in this way, a guide fixing part 410 is provided near the lower front-rear center position of these fixing parts.

[0138] Therefore, a fixing part group consisting of three fixing parts, namely adjacent mounting member fixing parts 420 in the front-rear direction and the guide fixing part 410 located below them, is arranged so that a triangle connecting the axial lines C2 of the front and rear bolts 160 and the axial line C1 of the bolt 330 below them forms an isosceles triangle with the lower side as the apex in side view. In other words, the axial line C1 of the bolt 330 is located near the lower of the front-rear center position of the straight line connecting the axial lines C2 of adjacent bolts 160 in the front-rear direction in side view.

[0139] Such a positional relationship between the guide fixing portion 410 and the three adjacent mounting member fixing portions 420 in the front and rear direction is also applied between the second roller mounting member 150 from the front and the third roller mounting member 150 from the front in the front roller group 142. That is, in the front roller group 142, the mounting member fixing portions 420 by the bolts 160 located at the rear end of the front first roller mounting member 150A and the front end of the rear first roller mounting member 150A are arranged close to each other in the front and rear direction so as to be aligned side by side in a side view. And, the guide fixing portion 410 by the rear mounting portion 320 of the crawler guide 300 is provided near the lower front-rear center position of these fixing portions.

[0140] Furthermore, the crawler unit 5 has the following configuration with respect to the arrangement of the adjacent mounting member fixing parts 420 in the front-rear direction and the guide fixing part 410 located below them. That is, the boss part 323 constituting the guide fixing part 410 is located between the centers of the boss parts 156, 256 constituting the adjacent mounting member fixing parts 420 in the front-rear direction in the front-rear direction. In other words, the entire boss part 323 is contained between the vertical lines passing through the axial lines C2 of the bolts 160 of the adjacent mounting member fixing parts 420 in the front-rear direction in the front-rear direction in the front-rear direction. Note that the boss parts 156, 256 through which the bolt 160 passes and the boss part 323 through which the bolt 330 passes have approximately the same outer diameter.

[0141] In the front roller group 142, the arrangement of the first roller mounting member 150A located in the front-to-rear center, the crawler guide 300, the front and rear fixing portion groups, and the rollers 103 is symmetrical or approximately symmetrical in the front-to-rear direction around the position of the axis C3 of the roller support shaft 180 in a side view (see FIG. 8). In addition, in a side view, the inclination of the outer slope portion 321 and the inner oblique side portion 322 of the mounting portion 320 of the crawler guide 300 is aligned with the inclination of the mounting bracket portions 152, 252 of the roller mounting member 150 located in front of and behind each mounting portion 320.

[0142] That is, in the crawler guide 300, the front mounting portion 320 has its outer slope portion 321 facing parallel to the lower rear oblique side portion of the mounting bracket portion 252 of the second roller mounting member 150B, and its inner slope portion 322 facing parallel to the lower front oblique side portion of the mounting bracket portion 152 of the front first roller mounting member 150A. Also, the rear mounting portion 320 has its inner slope portion 322 facing parallel to the lower rear oblique side portion of the mounting bracket portion 152 of the front first roller mounting member 150A, and its outer slope portion 321 facing parallel to the lower front oblique side portion of the mounting bracket portion 152 of the rear first roller mounting member 150A.

[0143] Thus, in the front roller group 142, the crawler guide 300 is provided so that the front and rear mounting parts 320 correspond to the inverted "V" shaped recesses in the zigzag shape (concave and convex shape) formed by the three roller mounting members 150 in a side view. Here, the inverted "V" shaped recesses are recessed parts that are inverted "V" shaped in a side view formed by the oblique sides of the mounting bracket parts 152, 252 that face each other between the front and rear roller mounting members 150 adjacent to each other in the front and rear. As a result, the three fixing parts that position the axis lines of the bolts 160, 330 at the apexes of an inverted isosceles triangle in a side view as described above, that is, the two front and rear mounting member fixing parts 420 and one guide fixing part 410, are concentrated and arranged as a fixing part group.

[0144] In addition, the left and right side portions 112a, through which the bolts 160 and 330 pass, have a shape at the front portion, which is the portion where the front roller group 142 is arranged, that corresponds to the arrangement of a fixing portion group consisting of three fixing portions for the guide fixing portion 410 and the mounting member fixing portion 420, on the lower edge.

[0145] Specifically, the left and right side surface portions 112a have protrusions 112b in a shape that is generally triangular or generally trapezoidal and convex downward with the guide fixing portion 410 as the apex in a side view (see Figs. 7 and 8). The side surface portions 112a position the lower ends (apexes) of the protrusions 112b between the adjacent wheel support portions 151, 251 in the front-to-rear direction, and have recesses to avoid interference with the wheel support portions 151, 251, forming a zigzag shape (uneven shape) in a side view.

[0146] According to the combine harvester 1 of this embodiment having the above-mentioned configuration, the support structure of the rollers 103 in the crawler section 5 of the traveling device 4 can be easily attached and detached to the track frame 100 and has sufficient strength.

[0147] In the crawler unit 5, the pair of left and right rollers 103 are fixed and supported between the left and right side surface portions 112a or between the left and right side surface portions 116a of the track frame 100 by a roller mounting member 150 in which cylindrical roller support portions 151, 251 and mounting bracket portions 152, 252 including boss portions 156, 256 are formed as an integral member. With this configuration, the fixing portion of the roller mounting member 150 to the track frame 100 can be a fastening portion in which the cylindrical boss portions 156, 256 are sandwiched between the left and right side surface portions 112a or between the left and right side surface portions 116a, and which is fastened by a bolt 160 that penetrates these side plates and the boss portions 156, 256. This makes it possible to obtain sufficient strength as a support structure for the rollers 103, and to suppress defects such as deformation of the track frame 100.

[0148] Moreover, the roller mounting member 150 can be easily removed from the track frame 100 by releasing the fastening by the bolt 160 and removing the bolt 160. This makes it possible to easily attach and detach the roller 103 to the track frame 100, and improves the maintainability of the crawler unit 5.

[0149] The rollers 103 are mounted as a pair on the left and right sides of the track frame 100 via roller mounting members 150. With this configuration, the mounting structure of the rollers 103 on the track frame 100 can be made simple and lightweight.

[0150] Moreover, the crawler guide 300 disposed below the track frame 100 has a crawler guide main body 310 and an attachment portion 320 including a boss portion 323. With this configuration, the fixed portion of the crawler guide 300 to the track frame 100 can be a fastening portion in which the cylindrical boss portion 323 is sandwiched between the left and right side surface portions 112a or between the left and right side surface portions 116a, and a bolt 330 passes through these side plates and the boss portion 323. This makes it possible to obtain sufficient strength as a support structure for the crawler guide 300, and to suppress defects such as deformation of the track frame 100.

[0151] Moreover, the crawler guide 300 can be easily removed from the track frame 100 by releasing the fastening by the bolts 330 and removing the bolts 330. This allows the crawler guide 300 to be easily attached and detached to the track frame 100, improving the maintainability of the crawler section 5. Also, the mounting structure of the crawler guide 300 to the track frame 100 can be made simple and lightweight.

[0152] Furthermore, in the crawler unit 5, the guide fixing portion 410 is located lower than the mounting member fixing portion 420. With this configuration, it becomes possible to easily attach and detach the crawler guide 300, which is replaced more frequently than the rollers 103, to the track frame 100. This allows for good maintainability of the crawler unit 5.

[0153] Furthermore, the guide fixing portion 410, which is the portion where the crawler guide 300 is fixed to the track frame 100, is located between adjacent roller mounting members 150 in the front-rear direction. With this configuration, good accessibility to the guide fixing portion 410 can be obtained, and a working space for the guide fixing portion 410 can be easily secured. This makes it possible to easily attach and detach the crawler guide 300 to the track frame 100, and provides good maintainability for the crawler section 5.

[0154] In particular, in this embodiment, the guide fixing parts 410 are arranged in a concentrated manner as a fixing part group, with two front and rear mounting member fixing parts 420 and one guide fixing part 410. This configuration makes it possible to efficiently attach and detach the crawler guide 300 and the wheel mounting member 150, improving the maintainability of the crawler unit 5.

[0155] Furthermore, in the portion of the track frame 100 that supports the front roller set 142, first side plates 112 are provided on both the left and right sides of the square pipe-shaped main frame 111, and the portions of the first side plates 112 that extend downward from the main frame 111 form left and right side portions 112a that support the roller mounting member 150 and the crawler guide 300. With this configuration, sufficient strength can be easily obtained with a simple configuration for the support structure for the rollers 103 and crawler guide 300, and for the track frame 100.

[0156] As described above, according to the configuration of the crawler section 5 of this embodiment, the support configuration of the roller 103 using the roller mounting member 150 on the track frame 100, and the support configuration of the crawler guide 300 on the track frame 100, make it possible to obtain a traveling device 4 that is lightweight and has excellent strength while improving maintainability.

[0157] Additionally, the crawler guide 300 is provided so that the front and rear mounting parts 320 correspond to inverted "V" shaped recesses in the zigzag shape (concave-convex shape) formed by the three roller mounting members 150 in a side view. This configuration allows efficient use of internal spaces such as the front support space 113 in the track frame 100. This allows the support structure for the rollers 103 and crawler guide 300 in the crawler unit 5 to be compact while still providing sufficient strength.

[0158] The combine harvester according to the present invention described above using the embodiments is not limited to the above-mentioned embodiments, and various aspects can be adopted within the scope of the spirit of the present invention. [Explanation of symbols]

[0159] 1 Combine (work vehicle) 4 Running gear 5 Crawler section 100 Truck Frame 103 Wheel 104 Crawler Belt 111 Main frame 112 1st side plate 112a Side part 113 Front support space 116 Second side plate 116a Side part 119 Rear support space 140 Wheel Unit 150 Wheel mounting parts 150A First roller mounting member 150B Second roller mounting member 151 Wheel support 152 Mounting bracket part 160 volts 180 Wheel support shaft 251 Wheel support 252 Mounting bracket part 300 Crawler Guide 310 Crawler guide body 320 Mounting part 330 Volts 410 Guide fixing part 420 Mounting member fixing part

Claims

1. A work vehicle equipped with a crawler-type traveling device having a pair of left and right crawler units, The crawler unit includes: A truck frame having left and right side portions, the lower sides of the left and right side portions being open; A pair of rollers located on both left and right sides of the track frame in the left-right direction; A wheel mounting member that supports the pair of wheels on the truck frame; a crawler guide located between the pair of rollers in the left-right direction and guiding a crawler belt; The roller mounting member is A wheel support portion for supporting the pair of wheels on both the left and right sides; a mounting bracket portion located between the left and right side portions and receiving the fixing of the truck frame; The crawler guide includes a crawler guide main body portion that acts on the crawler belt, and a mounting portion that is located between the left and right side portions and receives the fixation of the track frame, A fixing portion of the crawler guide to the track frame is located lower than a fixing portion of the roller mounting member to the track frame. A work vehicle characterized by:

2. The roller mounting members are arranged at intervals in the extension direction of the track frame, The fixed portion of the crawler guide relative to the track frame is located between the adjacent roller mounting members.

2. The work vehicle according to claim 1 .

3. The roller mounting member has a substantially triangular shape with the lower side being the apex side when viewed from the side.

3. The work vehicle according to claim 2.

4. The crawler guide is provided so that the mounting portion corresponds to a concave portion in an uneven shape formed by the plurality of roller mounting members in a side view.

4. The work vehicle according to claim 3.

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