Work vehicle

Abstract

To provide a work vehicle capable of absorbing an attachment error of a constant velocity joint and saving space.SOLUTION: A work vehicle comprises: a machine body frame 2; a front axle case 20; a suspension device 100; a first shaft 210 disposed at the lower part of a clutch housing 5a, to which driving force is transmitted from an engine 3 through a transmission device; a second shaft 220 to which the driving force from the first shaft 210 is transmitted; a third shaft 230 which transmits to an axle the driving force transmitted from the second shaft 220; a constant velocity joint 240 which bendably connects the front end side of the second shaft 220 and the rear end side of the third shaft 230 at a position corresponding to an oscillation shaft 130; and a connection part (spline part 250) which connects the rear end side of the second shaft 220 and the front end side of the first shaft 210 so as to permit relative axial movement of the second shaft 220 and the first shaft 210.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to the technology of work vehicles. [Background technology]

[0002] Conventionally, technology for work vehicles has been publicly known, as described in Patent Document 1, for example.

[0003] Patent Document 1 describes a tractor. In this tractor, the driving force of the engine is changed by a transmission in a transmission case and transmitted to an axle in a front axle case via a front-wheel drive shaft located below the vehicle body. The front axle case is supported by a swingable case support (suspension device) so as to be swingable relative to the vehicle body.

[0004] In a tractor equipped with the above-described suspension device, it is necessary to provide a joint that allows the front drive shaft to bend so as to follow the swing of the front axle case. In the tractor disclosed in Patent Document 1, two universal joints are provided on the front drive shaft. This allows the front drive shaft to bend at the locations where the universal joints are provided. Furthermore, when two universal joints are provided, assembly errors in one universal joint can be absorbed by the other universal joint.

[0005] However, when two universal joints are provided on the front wheel drive shaft as in the tractor of Patent Document 1, it is difficult to save space below the machine body, and further improvements are required. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3155738 Summary of the Invention [Problem to be solved by the invention]

[0007] One aspect of the present disclosure has been made in consideration of the above-described circumstances, and the problem it aims to solve is to provide a work vehicle that can absorb assembly errors of constant velocity joints and can also save space. [Means for solving the problem]

[0008] The problem to be solved by one embodiment of the present disclosure has been described above, and next, the means for solving this problem will be described.

[0009] A work vehicle according to one aspect of the present disclosure includes a body frame to which an engine is fixed, a front axle case that supports an axle of a front wheel, a suspension device that supports the front axle case so that the front axle case can swing about a swing axis relative to the body frame, and a suspension device that is disposed below a first case that houses a transmission. and is supported rotatably and non-swingably relative to the first case. a first shaft to which the driving force transmitted from the engine via the transmission is transmitted; and a second shaft disposed in front of the first shaft to which the driving force from the first shaft is transmitted. 1 bottle a second shaft and a and is supported rotatably and non-swingably with respect to the front axle case. the third shaft that transmits the driving force transmitted from the second shaft to the axle; a constant velocity joint that flexibly connects the front end side of the second shaft and the rear end side of the third shaft at a position corresponding to the oscillation axis; and a connection portion that connects the rear end side of the second shaft and the front end side of the first shaft so as to allow relative axial movement of the second shaft and the first shaft, wherein the connection portion connects the second shaft and the first shaft by a spline structure in which a first engagement portion formed on an inner peripheral surface is engaged with a second engagement portion formed on an outer peripheral surface of the rear end side of the second shaft and the front end side of the first shaft, and is displaceable between a connection position where the rear end side of the second shaft and the front end side of the first shaft are connected and a connection release position where the connection position moves from the connection position to the first shaft side or the second shaft side and releases the connection between the first shaft and the second shaft. According to one aspect of the present disclosure, it is possible to absorb assembly errors of a constant velocity joint and achieve space savings. Furthermore, according to one aspect of the present disclosure, it is possible to improve assembly. Furthermore, according to one aspect of the present disclosure, by connecting the second shaft and the first shaft by a spline structure, it is possible to more effectively absorb assembly errors of the constant velocity joint.

[0010] According to one aspect of the present disclosure, the rear end of the second shaft is disposed between the engine and the first case, and is located rearward of the second case that houses a flywheel. According to one aspect of the present disclosure, assembly errors of constant velocity joints can be absorbed more effectively.

[0013] In a work vehicle according to one aspect of the present disclosure, blocking portions are provided on both the front and rear sides of the inner surface of the connection portion to block the gap between the inner surface and the outer surfaces of the rear end side of the second shaft and the front end side of the first shaft. According to one aspect of the present disclosure, maintainability can be improved.

[0014] A work vehicle according to one aspect of the present disclosure includes a cover portion that covers the constant velocity joint from below and has an outlet portion formed therein that can discharge foreign matter that has entered the interior. According to one aspect of the present disclosure, even if a foreign object enters the inside of the cover portion, the foreign object can be expelled. According to one aspect of the present disclosure In the work vehicle, the cover portion has a bottom surface on which an inclined portion is formed that slopes downward toward the rear, and the discharge portion is formed on the rear lower portion of the side surface of the cover portion. [Effects of the Invention]

[0015] According to one aspect of the present disclosure, it is possible to absorb assembly errors of a constant velocity joint and to achieve space saving. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a side view showing the overall configuration of a tractor according to one embodiment of the present disclosure. [Figure 2]FIG. 2 is an exploded perspective view showing the tractor's body frame, engine, transmission case, clutch housing, flywheel housing, front axle case, steering device, and suspension device. [Figure 3] FIG. 2 is a perspective view showing a flywheel housing, a front axle case, a steering device, and a suspension device. [Figure 4] FIG. 2 is an exploded perspective view showing the front axle case, the suspension device, and the drive transmission shaft. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 2 is a side cross-sectional view showing the suspension device and the drive transmission shaft. [Figure 9] FIG. 4 is an exploded bottom perspective view showing the support member and the joint cover. [Figure 10] FIG. 4 is an enlarged side cross-sectional view showing the drive transmission shaft at the connection position. [Figure 11] FIG. 4 is an enlarged side cross-sectional view showing the drive transmission shaft in the disconnected position. [Figure 12] XX cross-sectional view in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0017] In the following description, the directions indicated by arrows U, D, F, B, L, and R in the figures are defined as upward, downward, forward, backward, leftward, and rightward, respectively.

[0018] First, the overall configuration of a tractor 1 according to one embodiment of the present disclosure will be described.

[0019] The tractor 1 shown in Figure 1 mainly comprises a body frame 2, an engine 3, a hood 4, a transmission case 5, front wheels 6, rear wheels 7, fenders 8, a lifting device 9, a cabin 10, a front axle case 20, a steering device 30, a suspension device 100, a drive transmission shaft 200, and a cover member 300.

[0020] The machine body frame 2 is a frame-shaped member formed by appropriately combining a plurality of plate materials. The machine body frame 2 is formed in a generally rectangular shape when viewed from above (see Figure 2). The machine body frame 2 is disposed at the front of the tractor 1 with its longitudinal direction facing the front-to-rear direction. An engine 3 is fixed to the rear of the machine body frame 2. The engine 3 is covered by a hood 4. A transmission case 5 is fixed to the rear of the engine 3. A muffler 4a that discharges exhaust gas from the engine 3 is disposed on the right side of the hood 4.

[0021] An oil pan 3a capable of storing engine oil is provided below the engine 3. A recess 3b extending in the front-rear direction is formed on the lower surface of the oil pan 3a (engine 3) (see FIG. 12).

[0022] The transmission case 5 houses a power transmission mechanism (not shown). As shown in FIG. 2, a clutch housing 5a that houses the power transmission mechanism (such as a transmission and a clutch) (not shown) is provided in front of the transmission case 5. A shaft support portion 5b that supports a drive transmission shaft 200 (described later) is provided in the lower part of the clutch housing 5a (see FIG. 8). In addition, a flywheel housing 5c ​​that houses a flywheel is provided in front of the clutch housing 5a (between the engine 3).

[0023] The front portion of the vehicle frame 2 is supported by a pair of left and right front wheels 6 via a front axle mechanism (such as a front axle case 20, which will be described later). The rear portion of the transmission case 5 is supported by a pair of left and right rear wheels 7 via a rear axle mechanism (not shown). The pair of left and right rear wheels 7 are generally covered from above by fenders 8.

[0024] A lifting device 9 is provided at the rear of the transmission case 5. Various types of working equipment (for example, a cultivator) can be attached to the lifting device 9. The lifting device 9 can raise and lower the attached working equipment by using an actuator such as a hydraulic cylinder.

[0025] The power of the engine 3 is changed in speed by a transmission (not shown) housed in the clutch housing 5a, and then transmitted to the front axle mechanism by the drive transmission shaft 200, and can be transmitted to the front wheels 6 via the front axle mechanism. Furthermore, the power changed in speed by the transmission can be transmitted to the rear wheels 7 via the rear axle mechanism. In this way, the front wheels 6 and rear wheels 7 are driven to rotate by the power of the engine 3, and the tractor 1 can travel. Furthermore, the power of the engine 3 can drive a working device attached to the lifting device 9.

[0026] A cabin 10 is provided behind the engine 3. The cabin 10 is mounted on the vehicle body (transmission case 5, etc.). A living space for the driver is formed inside the cabin 10. A seat 11 for the driver to sit in is arranged in the living space. A steering wheel 12 for adjusting the turning angle of the front wheels 6 is also arranged in the front of the cabin 10.

[0027] The front axle case 20 shown in Figures 2 to 4 houses the axles (not shown) of the front wheels 6. The front axle case 20 is arranged below the vehicle frame 2. The front axle case 20 is formed in a shape that is long in the left-right direction. The front axle case 20 is formed hollow, and the axles of the front wheels 6 are arranged in the internal space. The front wheels 6 are provided on both left-right sides of the front axle case 20 via axles. The front axle case 20, together with a steering cylinder 31 described later, constitutes a front axle mechanism. The front axle case 20 is equipped with a shaft portion 21.

[0028] The shaft portion 21 shown in Figures 4 and 8 is a portion that protrudes forward and backward from the left-right center of the front axle case 20. The shaft portion 21 is formed in a generally cylindrical shape with its axis facing the front-rear direction. As shown in Figure 8, of the front and rear shaft portions 21, the rear shaft portion 21 is formed with an insertion hole 21a that opens rearward and communicates with the internal space.

[0029] 2 steers the front wheels 6 in accordance with the amount of operation of the steering wheel 12. The steering device 30 constitutes a power steering mechanism that uses hydraulic pressure to assist steering. The steering device 30 includes a steering cylinder 31, a steering valve 32, and a first hose 33.

[0030] 3 is operated by hydraulic pressure of oil supplied by an appropriate pump (not shown) to change the turning angle of the front wheels 6. The steering cylinder 31 is provided in front of the front axle case 20.

[0031] The steering valve 32 supplies oil to the steering cylinder 31 in accordance with the amount of operation of the steering wheel 12. The steering valve 32 is provided on the upper part of the flywheel housing 5c.

[0032] The first hose 33 connects the steering cylinder 31 and the steering valve 32. A pair of first hoses 33 are provided so as to be connected to both the left and right sides of the steering cylinder 31.

[0033] In the above-described steering device 30, the steering valve 32 is driven in accordance with the amount of operation of the steering wheel 12, whereby oil is supplied to the steering cylinder 31 via the first hose 33, and the steering cylinder 31 is operated by hydraulic pressure, thereby steering the front wheels 6.

[0034] 3 and 4 absorbs vibrations transmitted from the front axle case 20 (front wheel 6) to the vehicle frame 2. The suspension device 100 supports the front axle case 20 so that it can swing relative to the vehicle frame 2. The suspension device 100 includes a support member 110, a swing member 120, a swing shaft 130, a suspension cylinder 140, an accumulator 150, and a second hose 160.

[0035] The support member 110 shown in Figures 4, 5, 8 and 9 is fixed to the vehicle frame 2 and supports the swing axis 130, which is the axis (with an axis oriented in the left-right direction) that serves as the swing center of the front axle case 20.

[0036] The support member 110 is formed in a generally plate shape with its plate surface facing up and down. The support member 110 is formed, for example, by casting. As shown in FIGS. 8 and 12 , the support member 110 is fixed to the lower surface of the aircraft frame 2. As a result, the support member 110 is disposed so as to be located below the engine 3. The support member 110 includes a fixing portion 111, a central portion 112, a recess 113, a first support portion 114, and a second support portion 115.

[0037] 5 is a portion that is fixed to the underside of the body frame 2. The fixing portions 111 constitute both left and right end portions of the support member 110. The fixing portions 111 are formed with holes through which fasteners for fixing the support member 110 are inserted.

[0038] The central portion 112 constitutes the central portion in the left-right direction of the support member 110. As shown in Fig. 12, the height position of the central portion 112 is formed to be raised from the surrounding area so that the height position of the central portion 112 is approximately the same as the height position of the fixing portion 111.

[0039] The recesses 113 are portions formed to be recessed downward between the left and right fixing portions 111 and the central portion 112. That is, a pair of recesses 113 are provided so as to be located on both left and right sides of the central portion 112. The recesses 113 are formed so as to extend in the front-rear direction.

[0040] 5 and 9 is a portion that supports the oscillation shaft 130. A pair of first support portions 114 are formed so as to extend downward from both left and right end portions (fixed portions 111) of the support member 110. The first support portion 114 is formed in a generally plate shape with the plate surface facing left and right. A hole is formed in the first support portion 114 through which the oscillation shaft 130 is inserted.

[0041] The second support portion 115 is a portion that supports the oscillation shaft 130 together with the first support portion 114. The second support portion 115 is disposed at the center of the support member 110 in the left-right direction, with a predetermined distance between them and the first support portion 114. In the illustrated example, a pair of second support portions 115 are formed so as to extend downward from a pair of recesses 113. The extension dimension of the second support portion 115 is greater than the extension dimension of the first support portion 114 (see FIG. 12). The second support portion 115 is formed in a generally plate shape with its plate surface facing left-right. A hole through which the oscillation shaft 130 is inserted is formed in the second support portion 115.

[0042] 4, 6, and 8 supports the front axle case 20 and is supported so as to be able to swing relative to the support member 110. The swing member 120 is formed, for example, by casting. The swing member 120 includes a main body portion 121, a guide groove portion 122, and a connecting portion 123.

[0043] The main body 121 is a portion that supports the front axle case 20. The main body 121 constitutes the front portion of the swinging member 120. The main body 121 is formed in a shape that is long in the front-rear direction. A through-hole 121a that penetrates the main body 121 in the front-rear direction is formed in the main body 121. Furthermore, a recess 121b that opens in the left-right direction and downward (recessed upward) is formed in a midpoint in the front-rear direction of the main body 121. As shown in FIG. 8, both sides of the recess 121b in the front-rear direction communicate with the through-hole 121a.

[0044] 8, the front axle case 20 is disposed inside the recess 121b. In this state, the front and rear shafts 21 of the front axle case 20 are inserted into the through-holes 121a, respectively. As a result, the front axle case 20 is supported by the main body 121 (swing member 120) so as to be swingable around the shafts 21.

[0045] The guide groove portion 122 is a portion that can guide the first hose 33. The guide groove portion 122 is formed on the upper surface of the main body portion 121 so as to extend in the front-rear direction. The guide groove portion 122 is formed on the center side of the main body portion 121 in the front-rear direction. The guide groove portion 122 is formed so that the groove depth dimension decreases toward the front side.

[0046] The connecting portion 123 is a portion that is connected to the support member 110 via the swing shaft 130. The connecting portion 123 constitutes the rear portion of the swing member 120. A pair of connecting portions 123 are formed so as to extend from the rear portion of the main body portion 121 toward both left and right sides of the support member 110 (the first support portion 114 and the second support portion 115). The extending tip ends of the pair of connecting portions 123 are located in the space between the first support portion 114 and the second support portion 115. A hole through which the swing shaft 130 is inserted is formed in the extending tip end of the connecting portion 123.

[0047] The oscillation shaft 130 shown in Fig. 4 serves as the oscillation center of the oscillation member 120. The oscillation shaft 130 is formed in a substantially cylindrical shape with its axis oriented in the left-right direction. A pair of oscillation shafts 130 are provided so as to connect both the left and right sides of the oscillation member 120 and the support member 110. The oscillation shaft 130 is inserted through the connecting portion 123 of the oscillation member 120 and the first support portion 114 and the second support portion 115 of the support member 110, thereby connecting the oscillation member 120 and the support member 110.

[0048] The suspension cylinders 140 absorb vibrations by the flow resistance of oil supplied by an appropriate pump (not shown). The suspension cylinders 140 absorb vibrations by expanding and contracting in the vertical direction. The suspension cylinders 140 are arranged to connect the machine body frame 2 and the oscillating member 120. Specifically, the upper end of the suspension cylinder 140 is supported on the inner surface of the machine body frame 2 around an axis facing in the left-right direction. The lower end of the suspension cylinder 140 is supported on the side of the main body 121 of the oscillating member 120 around an axis facing in the left-right direction. A pair of suspension cylinders 140 are arranged to connect the left and right sides of the machine body frame 2 and the oscillating member 120.

[0049] The accumulator 150 absorbs vibrations of the suspension cylinders 140. The accumulator 150 is provided on the left side of the lower part of the flywheel housing 5c. Two accumulators 150 (a pair) are provided. One accumulator 150 is connected to the oil chamber on the head side of the pair of suspension cylinders 140, and the other accumulator 150 is connected to the oil chamber on the rod side of the pair of suspension cylinders 140.

[0050] The second hoses 160 connect the pair of suspension cylinders 140 and the pair of accumulators 150. Two second hoses 160 are provided for each suspension cylinder 140.

[0051] The suspension device 100 as described above supports the front axle case 20 to the vehicle frame 2 so that it can swing about a swing shaft 130 via a support member 110 and a swing member 120. Furthermore, a suspension cylinder 140 interposed between the front axle case 20 side (swing member 120) and the vehicle frame 2 can absorb vibrations transmitted from the front axle case 20 (front wheel 6) to the vehicle frame 2.

[0052] The drive transmission shaft 200 shown in Figures 4, 7, and 8 transmits power from the engine 3 (transmission) to an axle in the front axle case 20. As shown in Figure 8, the drive transmission shaft 200 is disposed below the engine 3 and the clutch housing 5a. The drive transmission shaft 200 is formed in a generally cylindrical shape with its axis oriented in the longitudinal direction. The drive transmission shaft 200 includes a first shaft 210, a second shaft 220, a third shaft 230, a constant velocity joint 240, a spline portion 250, a bearing 260, an O-ring 270, and a movement restricting portion 280.

[0053] 7, 8, and 10, the driving force transmitted from the engine 3 via the transmission is transmitted to the first shaft 210. The first shaft 210 constitutes the rear portion of the drive transmission shaft 200. As shown in FIGS. 8 and 10, the first shaft 210 is rotatably supported with respect to the clutch housing 5a by a shaft support portion 5b at the bottom of the clutch housing 5a. The first shaft 210 includes a transmission-side transmission portion 211 and a tooth portion 212.

[0054] The transmission-side transmission part 211 is a part to which the driving force (rotation) from the power transmission mechanism is transmitted. The transmission-side transmission part 211 is formed in a shape that is larger in diameter than other parts of the first shaft 210. The transmission-side transmission part 211 is provided at the rear end part of the first shaft 210. A gear or the like that engages with the power transmission mechanism can be used as the transmission-side transmission part 211. As shown in Figures 8 and 10, the transmission-side transmission part 211 is housed inside the shaft support part 5b.

[0055] The toothed portion 212 shown in Figures 7 and 10 is a portion that engages with the spline portion 250, which will be described later. The toothed portion 212 is formed on the outer peripheral surface of the front portion of the first shaft 210. The toothed portion 212 is formed by forming a plurality of linear grooves that extend in the axial direction at equal intervals in the circumferential direction, so that the concaves and convexes are continuous in the circumferential direction. Note that the concaves and convexes are not shown in the figures. The portion of the first shaft 210 where the toothed portion 212 is formed has a reduced diameter compared to the other portions.

[0056] The second shaft 220 shown in Figures 7, 8, and 10 transmits driving force from the first shaft 210. The second shaft 220 is disposed forward of the first shaft 210 and constitutes the middle portion of the drive transmission shaft 200 in the front-rear direction. The length of the second shaft 220 is greater than the length of the first shaft 210. The rear end of the second shaft 220 is located rearward of the flywheel housing 5c ​​(see Figure 8). In this embodiment, the rear end of the second shaft 220 is located at a position overlapping with the clutch housing 5a in a plan view. The second shaft 220 is provided with a tooth portion 221.

[0057] The toothed portion 221 is a portion that engages with the spline portion 250, which will be described later. The toothed portion 221, similar to the toothed portion 212, is formed on the outer peripheral surface of the rear portion of the second shaft 220 so that projections and depressions continue in the circumferential direction. The portion of the second shaft 220 where the toothed portion 221 is formed has a reduced diameter compared to the other portions.

[0058] 7 and 8 transmits the driving force transmitted from the second shaft 220 to the axle (not shown) of the front wheels 6. The third shaft 230 is disposed forward of the second shaft 220, and constitutes the front part of the drive transmission shaft 200. The length dimension of the third shaft 230 is formed to be smaller than the length dimension of the second shaft 220.

[0059] 8, the third shaft 230 is inserted into the through-hole 121a of the swinging member 120 and is rotatably supported with respect to the swinging member 120 (main body portion 121). The front end portion of the third shaft 230 is inserted into the insertion hole 21a of the front axle case 20. The third shaft 230 includes an axle-side transmission portion 231.

[0060] The axle-side transmission part 231 is a part that transmits driving force (rotation) to the axle of the front wheel 6. The axle-side transmission part 231 is provided at the front end part of the third shaft 230. As shown in FIG. 8, the axle-side transmission part 231 is located in the space inside the front axle case 20. A gear (e.g., a bevel gear) that engages with the axle can be used as the axle-side transmission part 231.

[0061] 7 and 8 flexibly connects the front end side of the second shaft 220 and the rear end side of the third shaft 230. More specifically, constant velocity joint 240 transmits torque from second shaft 220 to third shaft 230 so that the second shaft 220 and the third shaft 230 rotate at a constant speed, even when there is an angle between them.

[0062] The constant velocity joint 240 is formed in a shape that has a larger diameter than the second shaft 220 and the third shaft 230. A constant velocity ball joint or the like can be used as the constant velocity joint 240. The constant velocity joint 240 is disposed at a position corresponding to the oscillation shaft 130. Specifically, the constant velocity joint 240 is disposed so that a portion that is the center of bending roughly coincides with (overlaps with) the axis of the oscillation shaft 130 in a side view (see FIG. 8).

[0063] 7, 8, and 10 connects the front end side of the first shaft 210 and the rear end side of the second shaft 220 so as to allow relative movement in the axial direction (front-rear direction) of the first shaft 210 and the second shaft 220. The spline portion 250 is formed in a substantially cylindrical shape so that the front end side of the first shaft 210 and the rear end side of the second shaft 220 can be inserted therethrough. The inner diameter of the spline portion 250 is formed to a dimension corresponding to the outer diameters of the first shaft 210 and the second shaft 220. The spline portion 250 is provided with a tooth portion 251.

[0064] The toothed portion 251 is a portion that engages with the toothed portion 212 of the first shaft 210 and the toothed portion 221 of the second shaft 220. The toothed portion 251 is formed on the inner peripheral surface of the spline portion 250 so that the concaves and convexes are continuous in the circumferential direction.

[0065] The first shaft 210 and the second shaft 220 can be connected by a spline structure by engaging the tooth portions 251 of the spline portion 250 as described above with the tooth portions 212 of the first shaft 210 and the tooth portions 221 of the second shaft 220. This allows the shafts to be connected so as to allow relative movement between the first shaft 210 and the second shaft 220 in the axial direction (front-rear direction) and restrict relative movement in the rotational direction (circumferential direction).

[0066] The bearings 260 shown in Figures 8 and 10 support each shaft of the drive transmission shaft 200 so as to be able to rotate smoothly. For example, ball bearings or the like can be used as the bearings 260. As shown in Figure 8, in this embodiment, a pair of bearings 260 (first-shaft-side bearings 260A) are provided at a distance in the front-rear direction between the shaft support portion 5b of the clutch housing 5a and the first shaft 210. In addition, a pair of bearings 260 (third-shaft-side bearings 260B) are provided at a distance in the front-rear direction between the through-hole 121a of the swinging member 120 (main body portion 121) and the third shaft 230.

[0067] 10 closes (seals) the gap between the inner circumferential surface of the spline portion 250 and the outer circumferential surfaces of the front end side of the first shaft 210 and the rear end side of the second shaft 220. The O-ring 270 is formed of a flexible material such as rubber. The O-rings 270 are provided on both sides of the inner circumferential surface of the spline portion 250 in the front-rear direction. In the illustrated example, the rear O-ring 270 is provided in a groove formed in the rear end part of the inner circumferential surface of the spline portion 250, and the front O-ring 270 is provided in a groove formed in the outer circumferential surface of the second shaft 220.

[0068] By providing the O-ring 270, it is possible to suppress leakage of the lubricant (grease, etc.) sealed between the inner surface of the spline portion 250 and the outer surfaces of the first shaft 210 and the second shaft 220, thereby reducing the burden of maintenance.

[0069] The movement restricting portion 280 shown in FIGS. 8 and 10 restricts movement of the spline portion 250 in the axial direction. The movement restricting portion 280 is fixed to the outer peripheral surface of the second shaft 220. In the example shown in FIG. 10, the movement restricting portion 280 is engaged with a groove formed on the outer peripheral surface of the second shaft 220, further forward than the groove in which the O-ring 270 is provided. A retaining ring or the like can be used as the movement restricting portion 280. Note that the movement restricting portion 280 is formed so that it can be disengaged from the groove on the outer peripheral surface by expanding its diameter. Furthermore, in the expanded diameter state, the movement restricting portion 280 can move back and forth on the second shaft 220 (see FIG. 11).

[0070] As shown in Figures 8 and 10, spline portion 250 is disposed between shaft support portion 5b of clutch housing 5a and movement restricting portion 280, thereby restricting forward and backward movement. Second shaft 220, to which movement restricting portion 280 is fixed, is restricted from moving rearward when movement restricting portion 280 abuts against spline portion 250 (see Figures 8 and 10). Furthermore, second shaft 220 is restricted from moving forward when constant velocity joint 240 connected to the front end thereof abuts against the rear end (e.g., an oil seal or the like provided in through hole 121a) of main body portion 121 (oscillating member 120) (see Figure 8). A certain amount of gap (e.g., about 1 mm) is formed between movement restricting portion 280 and spline portion 250, and between main body portion 121 and constant velocity joint 240. In this way, the second shaft 220 is connected to the first shaft 210 via the spline portion 250 so as to be allowed to move in the front-rear direction (axial direction) within the range of the above-mentioned gap.

[0071] Hereinafter, the position of the spline portion 250 that connects the front end side of the first shaft 210 and the rear end side of the second shaft 220 as described above will be referred to as the "connection position" (see FIG. 10). In this embodiment, the spline portion 250 in the connection position can be moved forward (toward the second shaft 220) to be displaced to a "disconnection position" where the connection with the first shaft 210 is released (see FIG. 11). In this case, the movement restricting portion 280 is moved forward to allow the spline portion 250 to move forward. As shown in FIG. 11, the movement restricting portion 280 that has moved forward is positioned so as to fit into a recessed (narrowed) portion in the outer circumferential surface of the second shaft 220. At this time, the shaft cover portion 310, which will be described later, is removed.

[0072] 11 shows a state in which the spline portion 250 is positioned at the disconnected position. In the disconnected position, the front-to-rear positions of the rear end of the second shaft 220 and the rear end of the spline portion 250 are approximately aligned. In this state, the second shaft 220 can be easily removed from the first shaft 210 by bending the second shaft 220 relative to the third shaft 230 via the constant velocity joint 240 and lowering the second shaft 220. Furthermore, by performing the reverse operation of the above, the second shaft 220 can be easily assembled to the first shaft 210 by raising the second shaft 220 to the position of the first shaft 210 and moving the spline portion 250 to the connected position.

[0073] The cover member 300 shown in Figure 8 covers the drive transmission shaft 200 from below. The cover member 300 is formed by appropriately bending a metal plate. The cover member 300 is disposed so as to bridge between the shaft support portion 5b of the clutch housing 5a and the support member 110. The cover member 300 includes a shaft cover portion 310 and a joint cover portion 320.

[0074] The shaft cover portion 310 covers the first shaft 210, the second shaft 220, and the spline portion 250 of the drive transmission shaft 200. More specifically, the shaft cover portion 310 covers both the left and right sides and the lower side of the first shaft 210, the second shaft 220, and the spline portion 250. The shaft cover portion 310 is formed in a generally box shape that is long in the front-rear direction. The rear end portion of the shaft cover portion 310 is fixed to the shaft support portion 5b.

[0075] The joint cover part 320 shown in Figures 8, 9 and 12 covers the constant velocity joint 240. More specifically, as shown in Figures 8 and 9, the joint cover part 320 covers both the left and right sides and the lower side of the constant velocity joint 240. The rear end part of the joint cover part 320 is fixed to the shaft cover part 310. Furthermore, both the left and right sides of the joint cover part 320 are fixed to the second support part 115 of the support member 110 (see Figure 9).

[0076] An opening 321 is formed on the side surface of the joint cover part 320, which opens in the left-right direction and communicates with the inside of the joint cover part 320. The opening 321 is formed in the lower rear corner of the side surface of the joint cover part 320. Foreign matter (e.g., mud, water, etc.) that has entered the inside of the joint cover part 320 can be discharged through the opening 321.

[0077] In the tractor 1 described above, by providing a constant velocity joint 240 on the drive transmission shaft 200, the drive transmission shaft 200 can be bent to follow the movement of the suspension device 100 (oscillation around the oscillating shaft 130) (see Figure 8).

[0078] Here, if an assembly error or the like occurs in the constant velocity joint 240 and the center of bending of the constant velocity joint 240 does not coincide with the axis of the oscillating shaft 130 in a side view, there is a risk that the drive transmission shaft 200 will not be able to follow the movement of the suspension device 100.

[0079] Therefore, in this embodiment, in addition to the constant velocity joint 240, the first shaft 210 and the second shaft 220 are connected by a spline structure using the spline portion 250. This allows relative movement in the axial direction of the first shaft 210 and the second shaft 220, as shown in Fig. 10, so that assembly errors of the constant velocity joint 240 can be absorbed.

[0080] Furthermore, when the first shaft 210 and the second shaft 220 are connected by a spline structure as in this embodiment, a certain amount of gap is formed between the outer circumferential surface of the second shaft 220 and the inner circumferential surface of the spline portion 250, which allows radial displacement (such as vertical movement) of the second shaft 220 relative to the spline portion 250 (creating backlash). In this embodiment, the second shaft 220 is formed relatively long, which makes it possible to increase the amount of displacement of the front end side (constant velocity joint 240 side) of the second shaft 220 corresponding to the amount of displacement due to backlash in the spline portion 250. This makes it possible to more effectively absorb assembly errors in the constant velocity joint 240.

[0081] As described above, in this embodiment, by adopting a spline structure for connecting the first shaft 210 and the second shaft 220, it is possible to absorb the above-mentioned assembly errors in the axial and radial directions of the drive transmission shaft 200. Furthermore, with the above configuration, it is possible to save space below the vehicle body, unlike when, for example, another constant velocity joint 240 is provided on the drive transmission shaft 200 to absorb assembly errors. This makes it possible to ensure the minimum ground clearance of the vehicle body.

[0082] Furthermore, the tractor 1 as described above can suitably route the hoses (first hose 33 and second hose 160) for operating the steering device 30 and the suspension device 100. The manner in which the hoses are routed will be described below.

[0083] 12, in this embodiment, an arrangement space A in which the hoses (the first hose 33 and the second hose 160) can be arranged is formed between the engine 3 and the support member 110. The arrangement space A includes a first arrangement space A1 and a second arrangement space A2.

[0084] The first routing space A1 is a space in which the first hose 33 of the steering device 30 is routed. The first routing space A1 is defined by the recess 3b of the engine 3 and the central portion 112 of the support member 110. The first routing space A1 is formed to extend in the front-rear direction.

[0085] A first hose 33 connected to a steering valve 32 at the rear of the engine 3 passes through the first routing space A1. The first hose 33 is arranged to extend over the central portion 112 of the support member 110 in the front-rear direction (see FIG. 3). In this embodiment, the first hose 33 that has passed through the first routing space A1 is guided forward along the guide groove portion 122 of the swinging member 120 and connected to the steering cylinder 31.

[0086] The second routing space A2 is a space in which the second hose 160 is routed. The second routing space A2 is defined by the left and right side surfaces of the engine 3 (oil pan 3a), the inner surface of the vehicle body frame 2 facing the side surfaces, and a pair of recesses 113 of the support member 110. A pair of second routing spaces A2 are formed so as to be located on both left and right sides of the first routing space A1. The second routing space A2 is formed so as to extend in the front-rear direction.

[0087] Left and right second hoses 160 connected to the accumulator 150 behind the engine 3 pass through left and right second routing spaces A2 and are connected to left and right suspension cylinders 140 (see FIG. 3).

[0088] As described above, in this embodiment, the first hose 33 and the second hose 160 can be routed by utilizing the routing space A formed between the engine 3 and the support member 110. Furthermore, by using the support member 110 of the suspension device 100 as a member that guides the first hose 33 and the second hose 160, the number of components can be reduced. Furthermore, because the support member 110 is interposed between each hose and the drive transmission shaft 200 (constant velocity joint 240, etc.), it is possible to prevent direct contact between the drive transmission shaft 200, which rotates at high speed, and each hose.

[0089] Here, the tractor 1 is designed to be equipped with a suspension device 100, but it is also possible to adopt a design that does not include the suspension device 100. If the suspension device 100 is not provided, a mechanism for swinging the drive transmission shaft 200 up and down is not required, and the drive transmission shaft 200 can be disposed at a higher position. In this case, it is also possible to dispose the drive transmission shaft 200 in place of the first hose 33 in the recess 3b (first routing space A1) of the oil pan 3a of the engine 3. In this way, in this embodiment, the engine 3 is designed to be highly versatile.

[0090] In this embodiment, the first hose 33 can be routed by utilizing the recess 3b of the engine 3 as described above. It is also assumed that the first hose 33 moves up and down and left and right in conjunction with the movement of the front axle case. According to this embodiment, the first hose 33 can be stably routed by using the first routing space A1 on the center side of the vehicle body in the left-right direction and the guide groove portion 122.

[0091] In addition, in this embodiment, the second routing space A2 formed on both the left and right sides of the first hose 33 can be used to suitably route the second hose 160 of the suspension cylinder 140 arranged on both the left and right sides of the vehicle body.

[0092] As described above, the tractor 1 (work vehicle) according to this embodiment has the following features: an aircraft frame 2 to which an engine 3 is fixed; a front axle case 20 that supports the axles of the front wheels 6; a suspension device (100) that supports the front axle case (20) so that the front axle case (20) can swing about a swing shaft (130) relative to the vehicle frame (2); a first shaft 210 that is disposed under a first case (clutch housing 5a) that accommodates a transmission, and to which driving force transmitted from the engine 3 via the transmission is transmitted; a second shaft 220 disposed in front of the first shaft 210 and to which a driving force from the first shaft 210 is transmitted; a third shaft 230 disposed in front of the second shaft 220 and configured to transmit the driving force transmitted from the second shaft 220 to the axle; a constant velocity joint (240) that flexibly connects a front end side of the second shaft (220) and a rear end side of the third shaft (230) at a position corresponding to the oscillation axis (130); a connection portion (spline portion 250) that connects a rear end side of the second shaft 220 and a front end side of the first shaft 210 so as to allow relative movement of the second shaft 220 and the first shaft 210 in the axial direction; It is equipped with the following.

[0093] With this configuration, it is possible to absorb any assembly error of the constant velocity joint 240 and to achieve space savings. That is, when a suspension device 100 is provided that supports the front axle case 20 so that it can swing about the swing shaft 130, it is necessary to provide a shaft with a bendable constant velocity joint 240 at a position corresponding to the swing shaft 130, and to bend the shaft to follow the movement of the suspension device 100. Here, if an assembly error occurs in the constant velocity joint 240, there is a risk that the shaft will not be able to follow the movement of the suspension device 100. In the tractor 1 (work vehicle) according to this embodiment, in addition to the constant velocity joint 240, the first shaft 210 and the second shaft 220 are connected by a connection part (spline part 250) that allows relative movement in the axial direction of the first shaft 210 and the second shaft 220, so that it is possible to absorb any assembly error of the constant velocity joint 240. Furthermore, when the connection using the connection portion (spline portion 250) is adopted, it is possible to save space below the vehicle body, unlike when another constant velocity joint 240 is provided to absorb the above-mentioned assembly error, and this makes it possible to ensure the minimum ground clearance of the vehicle body.

[0094] The rear end of the second shaft 220 is It is disposed between the engine 3 and the first case (clutch housing 5a), and is located rearward of the second case (flywheel housing 5c) that houses the flywheel.

[0095] This configuration allows for more effective absorption of assembly errors of the constant velocity joint 240. That is, when a connection using a connection portion (spline portion 250) is adopted, a certain amount of clearance is formed between the second shaft 220 and the connection portion (spline portion 250), allowing radial displacement (such as vertical movement) of the second shaft 220 relative to the connection portion (spline portion 250) (creating backlash). In this embodiment, the rear end of the second shaft 220 is positioned rearward of the flywheel housing 5c, thereby making the length of the second shaft 220 relatively large. By forming the second shaft 220 relatively long in this manner, it is possible to increase the amount of displacement of the front end side (constant velocity joint 240 side) of the second shaft 220 corresponding to the amount of displacement due to backlash of the connection portion (spline portion 250). This allows for more effective absorption of assembly errors of the constant velocity joint 240.

[0096] In addition, the connection portion (spline portion 250) is a connection position at which the rear end side of the second shaft 220 and the front end side of the first shaft 210 are connected; a disconnection position at which the shaft 210 moves from the connection position to the first shaft 210 side or the second shaft 220 side and disconnects the first shaft 210 and the second shaft 220; It is displaceable to.

[0097] This configuration can improve the ease of assembly. That is, by setting the connection portion (spline portion 250) to the disconnection position, the second shaft 220 can be easily attached to and detached from the first shaft 210, thereby improving the ease of assembly.

[0098] In addition, the connection portion (spline portion 250) is The second shaft 220 and the first shaft 210 are connected by a spline structure in which a first engagement portion (tooth portion 251) formed on the inner surface engages with a second engagement portion (tooth portion 212, tooth portion 221) formed on the outer surface of the rear end side of the second shaft 220 and the front end side of the first shaft 210.

[0099] With this configuration, the second shaft 220 and the first shaft 210 are connected by a spline structure, so that assembly errors of the constant velocity joint 240 can be absorbed more effectively.

[0100] In addition, on both sides of the inner circumferential surface of the connection portion (spline portion 250) in the front-to-rear direction, blocking portions (O-rings 270) are provided to block the gaps between the inner circumferential surface and the outer circumferential surfaces of the rear end side of the second shaft 220 and the front end side of the first shaft 210.

[0101] This configuration can improve maintainability, that is, it is possible to prevent leakage of lubricant (grease or the like) enclosed between the inner circumferential surface of the connection portion (spline portion 250) and the outer circumferential surfaces of the second shaft 220 and the first shaft 210, thereby reducing the burden of maintenance.

[0102] The constant velocity joint 240 is also covered from below with a cover (joint cover 320) having an outlet (opening 321) formed therein for discharging foreign matter that has entered the inside.

[0103] With this configuration, even if a foreign object gets inside the cover portion (joint cover portion 320), the foreign object can be expelled.

[0104] In addition, the tractor 1 (work vehicle) according to this embodiment is an aircraft frame 2 to which an engine 3 is fixed; a front axle case 20 that supports the axle of the front wheels and is swingable around a swing shaft 130; a shock absorber (suspension device 100) that absorbs vibrations transmitted from the front axle case 20 to the vehicle frame 2; a support member 110 that is fixed to the vehicle frame 2 so as to be positioned below the engine 3, supports the swing shaft 130, and defines an arrangement space A between the engine 3 and the support member 110, in which linear members (a first hose 33, a second hose 160) extending in the front-rear direction can be arranged; It is equipped with the following.

[0105] With this configuration, the linear members (first hose 33, second hose 160) can be routed in a suitable manner. That is, the linear members (first hose 33, second hose 160) can be routed by utilizing the routing space A formed between the engine 3 and the support member 110. Furthermore, by utilizing the support member 110 that supports the swing shaft 130 as a member that guides the linear members (first hose 33, second hose 160), the number of components can be reduced.

[0106] In addition, the engine 3 A recess 3b is formed on the underside so as to extend in the front-rear direction, The wiring space A is The recess 3b and the support member 110 define a first wiring space A1.

[0107] With this configuration, the linear member (first hose 33) can be routed by utilizing the recess 3b formed on the underside of the engine 3. Furthermore, depending on the model and type of the tractor (work vehicle), the recess 3b (first routing space A1) can also be used as a space for arranging the drive transmission shaft 200.

[0108] In addition, the linear members (first hose 33, second hose 160) are a first hose 33 connected from the rear side of the engine 3 to a steering cylinder provided in the front axle case 20; The first hose 33 is routed in the first routing space A1.

[0109] This configuration allows for suitable routing of the first hose 33. By routing the first hose 33 in the first routing space A1 formed by the recess 3b, the first hose 33, which moves up and down in conjunction with the movement of the front axle case 20, can be stably routed.

[0110] In addition, the wiring space A is The second wiring space A2 is defined by the side surface of the engine 3, the inner surface of the aircraft frame 2 facing the side surface, and the support member 110.

[0111] With this configuration, the second routing space A2 formed on the side of the engine 3 can be utilized to route the linear member (second hose 160).

[0112] Moreover, the shock absorber (suspension device 100) A buffer cylinder (suspension cylinder 140) is provided. The linear members (first hose 33, second hose 160) are a second hose 160 connected to the buffer cylinder (suspension cylinder 140) from the rear side of the engine 3; The second hose 160 is routed in the second routing space A2.

[0113] This configuration allows for suitable routing of the second hose 160. That is, the second routing space A2 located to the side of the engine 3 can be used to route the second hose 160.

[0114] The front axle case (20) is fixed to a swing member (120) supported by the support member (110) so as to be swingable around the swing shaft (130), The swinging member 120 is The guide groove 122 is formed on the top surface so as to extend in the front-rear direction and is capable of guiding the linear members (first hose 33, second hose 160).

[0115] With this configuration, the guide groove portion 122 formed on the upper surface of the swinging member 120 can be used to route the linear members (first hose 33, second hose 160).

[0116] Further, below the support member 110, a drive transmission shaft 200 is disposed which transmits the driving force from the engine 3 to the axle.

[0117] With this configuration, it is possible to protect the linear members (first hose 33, second hose 160). That is, by interposing the support member 110 between the drive transmission shaft 200 and the linear members (first hose 33, second hose 160), it is possible to prevent direct contact between the drive transmission shaft 200, which rotates at high speed, and the linear members (first hose 33, second hose 160).

[0118] Also, it is provided with a cover portion (joint cover portion 320) that is fixed to the support member 110 and covers the drive transmission shaft 200 from below.

[0119] With this configuration, the support member 110 can be used to fix the cover portion (joint cover portion 320) that covers the drive transmission shaft 200.

[0120] The tractor 1 according to this embodiment is one embodiment of a work vehicle according to the present invention. The clutch housing 5a according to this embodiment is one form of the first case according to the present invention. The flywheel housing 5c ​​according to this embodiment is one form of the second case according to the present invention. The spline portion 250 according to this embodiment is one form of the connecting portion according to the present invention. The tooth portion 251 according to this embodiment is one form of the first engagement portion according to the present invention. The toothed portion 212 and the toothed portion 221 according to this embodiment are one form of the second engaging portion according to the present invention. Moreover, the O-ring 270 according to this embodiment is one form of the blocking portion according to the present invention. The joint cover portion 320 according to this embodiment is one form of the cover portion according to the present invention. The suspension device 100 according to this embodiment is one form of the shock absorber according to the present invention. The first hose 33 and the second hose 160 according to this embodiment are one form of the linear member according to the present invention. The suspension cylinder 140 according to this embodiment is one form of the buffer cylinder according to the present invention. The opening 321 according to this embodiment is one form of the discharge portion according to the present invention.

[0121] Although one embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

[0122] For example, the shapes of the components (support member 110, swing member 120, drive transmission shaft 200, etc.) described in the above embodiment are merely examples and are not limited to the above-mentioned shapes, etc. The shapes of the components can be changed to any shape.

[0123] In the above embodiment, the rear end of the second shaft 220 is positioned rearward of the flywheel housing 5c, but the present invention is not limited to this. For example, the rear end of the second shaft 220 may be positioned in a position corresponding to the flywheel housing 5c ​​(overlapping with the flywheel housing 5c ​​in a plan view).

[0124] In the above embodiment, the transmission case 5, the clutch housing 5a, the flywheel housing 5c, etc. are exemplified as components that house the power transmission mechanism that transmits power from the engine 3, but the present invention is not limited to such an embodiment. For example, the transmission case 5, etc. may be formed integrally with one another, or may be further separated.

[0125] Furthermore, in the above embodiment, an example has been described in which the spline portion 250 is moved forward (toward the second shaft 220) when the connection between the first shaft 210 and the second shaft 220 is released, but the present invention is not limited to this. For example, the connection between the shafts may be released by moving the spline portion 250 rearward (toward the first shaft 210). In this case, the length dimension and the like of the first shaft 210 are set appropriately so that the spline portion 250 can be moved rearward. Specifically, the length dimensions of the first shaft 210 and the spline portion 250 can be set so as to ensure the movement distance of the spline portion 250.

[0126] Furthermore, in the above embodiment, an example was shown in which the spline portion 250 was movable between the connected position and the disconnected position, but this is not limited to such an embodiment, and for example, the movement may be disabled.

[0127] Furthermore, in the above embodiment, an example was shown in which a pair of second wiring spaces A2 are provided on the left and right sides, but the present invention is not limited to this configuration, and for example, one second wiring space A2 may be provided.

[0128] Furthermore, in the above embodiment, an example was shown in which the guide groove portion 122 was provided in the swinging member 120, but the present invention is not limited to this embodiment, and for example, the guide groove portion 122 may not be provided.

[0129] In the above embodiment, the hoses (first hose 33 and second hose 160) connected to the cylinder are routed in the routing space A. However, the present invention is not limited to this. For example, other linear members such as harnesses and wires may be routed in the routing space A.

[0130] In addition, in the above embodiment, the tractor 1 is used as an example of the work vehicle, but the work vehicle is not limited to this. For example, the work vehicle may be other agricultural vehicles, construction vehicles, industrial vehicles, etc. [Explanation of symbols]

[0131] 1 Tractor 20 Front axle case 100 Suspension device 200 Drive transmission shaft 300 Cover member

Claims

1. An aircraft frame to which the engine is fixed; a front axle case supporting the front wheel axle; a suspension device that supports the front axle case swingably about a swing axis relative to the vehicle frame; a first shaft disposed in a lower portion of a first case that houses a transmission, supported rotatably but non-oscillatably relative to the first case, and to which driving force transmitted from the engine via the transmission is transmitted; a second shaft disposed forward of the first shaft and to which a driving force from the first shaft is transmitted; a third shaft disposed forward of the second shaft and supported rotatably and non-swingably with respect to the front axle case, the third shaft transmitting the driving force transmitted from the second shaft to the axle; a constant velocity joint that flexibly connects a front end side of the second shaft and a rear end side of the third shaft at a position corresponding to the oscillation axis; a connection portion that connects a rear end side of the second shaft and a front end side of the first shaft so as to allow relative movement of the second shaft and the first shaft in an axial direction; Equipped with The connection portion is the second shaft and the first shaft are connected by a spline structure in which a first engagement portion formed on an inner peripheral surface is engaged with a second engagement portion formed on an outer peripheral surface of a rear end side of the second shaft and a front end side of the first shaft, By moving relative to both the first shaft and the second shaft, a connection position that connects the rear end side of the second shaft and the front end side of the first shaft; a disconnection position at which the coupling member moves from the connection position to the first shaft side or the second shaft side to disconnect the first shaft and the second shaft; is displaceable to Work vehicle.

2. The rear end of the second shaft a second case disposed between the engine and the first case and positioned rearward of a second case that houses a flywheel; The work vehicle according to claim 1.

3. blocking portions that block gaps between the inner circumferential surface of the connecting portion and the outer circumferential surfaces of the rear end side of the second shaft and the front end side of the first shaft, on both sides in the front-rear direction of the inner circumferential surface of the connecting portion; The work vehicle according to claim 1.

4. a cover portion that covers the constant velocity joint from below and has a discharge portion that can discharge foreign matter that has entered inside; A work vehicle according to any one of claims 1 to 3.

5. The cover portion is A bottom surface having a sloped portion that slopes downward toward the rear, The discharge section is A part formed on the rear lower part of the side surface of the cover part, A work vehicle according to claim 4.

Images