Work vehicle

Abstract

To provide a work vehicle capable of appropriately routing a linear member.SOLUTION: A work vehicle comprises: a machine body frame 2 to which an engine 3 is fixed; a front axle case 20 which supports an axle of a front wheel and can oscillate around an oscillation shaft 130; a suspension device 100 which absorbs vibration transmitted to the machine body frame 2 from the front axle case 20; and a support member 110 that is fixed to the machine body frame 2 so as to be positioned below the engine 3 and supports the oscillation shaft 130, and which partitions, between it and the engine 3, a routing space A capable of routing linear members (a first hose 33 and a second hose 160) extending in a longitudinal direction.SELECTED DRAWING: Figure 12

Description

Technical Field

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

Background Art

[0002] Conventionally, the technology of work vehicles is well-known. For example, it is as described in Patent Document 1.

[0003] Patent Document 1 describes a tractor. In the tractor, the driving force of an engine is transmitted through a transmission in a transmission case to an axle in a front axle case via a front wheel drive shaft disposed below the vehicle body. The front axle case is supported by a case swing support portion (suspension device) so as to be swingable with respect to the vehicle body.

[0004] In a tractor as described above, a cylinder using hydraulic pressure may be provided in a suspension device, a front axle case, or the like. In this case, it is required to suitably arrange linear members such as hoses for supplying oil to the cylinder.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] One aspect of the present disclosure has been made in view of the above situation, and the problem to be solved is to provide a work vehicle capable of suitably arranging linear members.

Means for Solving the Problems

[0007] The problem that one aspect of this disclosure aims to solve is as described above, and the means for solving this problem will now be explained.

[0008] A work vehicle according to one aspect of this disclosure includes a machine frame on which an engine is fixed, a front axle case that supports the front axle and is pivotable around a pivot axis, a damping device that absorbs vibrations transmitted from the front axle case to the machine frame, and a linear member that is fixed to the machine frame so as to be located below the engine and supports the pivot axis, and extends in the front-rear direction between itself and the engine. but arrangement It will be done The engine comprises a support member that partitions a routing space, the engine having a recess formed on its lower surface so as to extend in the front-rear direction, the routing space including a first routing space partitioned by the recess and the support member, the support member having a raised portion that rises towards the recess at a position opposite to the recess, and the linear member being positioned between it and the recess so as to extend front-rear. According to one aspect of this disclosure, linear members can be routed in a suitable manner. Furthermore, according to one aspect of this disclosure, linear members can be routed by utilizing a recess formed on the underside of the engine.

[0010] The linear member according to one aspect of the present disclosure includes a first hose connected from the rear side of the engine to a steering cylinder provided on the front axle case, and the first hose is routed in the first routing space. According to one aspect of this disclosure, the routing of the first hose can be suitably performed.

[0011] The routing space according to one aspect of the present disclosure includes a second routing space partitioned by the side surface of the engine, the inner surface of the aircraft frame facing the side surface, and the support member. According to one aspect of this disclosure, a linear member can be routed using a second routing space formed on the side of the engine.

[0012] The shock absorber according to one aspect of the present disclosure comprises a shock absorber cylinder, the linear member includes a second hose connected to the shock absorber cylinder from the rear side of the engine, and the second hose is routed in the second routing space. According to one aspect of this disclosure, the routing of the second hose can be suitably performed.

[0013] A work vehicle according to one aspect of the present disclosure comprises a pivoting member to which the front axle case is fixed and which is pivotably supported by the support member so as to pivot around the pivot axis, wherein the pivoting member has a guide groove formed on its upper surface so as to extend in the front-rear direction and is capable of guiding the linear member. According to one aspect of this disclosure, a linear member can be routed using a guide groove formed on the upper surface of the rocking member.

[0014] In one aspect of the present disclosure, a work vehicle is provided with a drive transmission shaft positioned below the support member, which transmits the driving force from the engine to the axle. According to one aspect of this disclosure, a linear member can be protected.

[0015] A work vehicle according to one aspect of the present disclosure comprises a cover portion fixed to the support member and covering the drive transmission shaft from below. According to one aspect of this disclosure, a cover portion that covers the drive transmission shaft can be fixed using a support member. [Effects of the Invention]

[0016] According to one aspect of this disclosure, assembly errors of constant velocity joints can be absorbed, and space can be saved. [Brief explanation of the drawing]

[0017] [Figure 1] A side view showing the overall configuration of a tractor according to one aspect of this disclosure. [Figure 2]Exploded perspective view showing the body frame, engine, transmission case, clutch housing, flywheel housing, front axle case, steering device and suspension device of a tractor. [Figure 3] Perspective view showing the flywheel housing, front axle case, steering device and suspension device. [Figure 4] Exploded perspective view showing the front axle case, suspension device and drive transmission shaft. [Figure 5] Perspective view showing the support member. [Figure 6] Perspective view showing the swing member. [Figure 7] Exploded perspective view showing the drive transmission shaft. [Figure 8] Side cross-sectional view showing the suspension device and drive transmission shaft. [Figure 9] Exploded bottom perspective view showing the support member and joint cover. [Figure 10] Enlarged side cross-sectional view showing the drive transmission shaft at the connection position. [Figure 11] Enlarged side cross-sectional view showing the drive transmission shaft at the disconnection position. [Figure 12] X-X cross-sectional view in FIG. 8.

Mode for Carrying Out the Invention

[0018] Hereinafter, the directions indicated by the arrows U, D, F, B, L, and R in the figures will be defined as the upward, downward, forward, backward, leftward, and rightward directions, respectively, for explanation.

[0019] First, the overall configuration of the tractor 1 according to one aspect of the present disclosure will be described.

[0020] The tractor 1 shown in FIG. 1 mainly includes a body frame 2, an engine 3, a bonnet 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, a cover member 300, and the like.

[0021] The machine frame 2 is a frame-like member formed by appropriately combining multiple plate materials. The machine frame 2 is formed in a roughly rectangular shape in plan view (see Figure 2). The machine frame 2 is positioned at the front of the tractor 1 with its longitudinal direction facing the front-to-back direction. The engine 3 is fixed to the rear of the machine frame 2. The engine 3 is covered by a bonnet 4. The transmission case 5 is fixed to the rear of the engine 3. A muffler 4a for discharging exhaust gas from the engine 3 is located on the right side of the bonnet 4.

[0022] An oil pan 3a capable of holding engine oil is provided at the bottom of the engine 3. A recess 3b is formed on the lower surface of the oil pan 3a (engine 3) so as to extend in the front-to-back direction (see Figure 12).

[0023] The transmission case 5 houses the power transmission mechanism (not shown). As shown in Figure 2, a clutch housing 5a, which houses the power transmission mechanism (transmission, clutch, etc.) (not shown), is provided in front of the transmission case 5. A shaft support portion 5b, which supports the drive transmission shaft 200 (described later), is provided at the bottom of the clutch housing 5a (see Figure 8). In addition, a flywheel housing 5c, which houses the flywheel, is provided in front of the clutch housing 5a (between it and the engine 3).

[0024] The front of the aircraft frame 2 is supported by a pair of front wheels 6 via a front axle mechanism (such as the front axle case 20 described later). The rear of the transmission case 5 is supported by a pair of rear wheels 7 via a rear axle mechanism (not shown). The pair of rear wheels 7 are generally covered from above by fenders 8.

[0025] A lifting device 9 is provided at the rear of the transmission case 5. Various work devices (for example, a tiller, etc.) can be attached to the lifting device 9. The lifting device 9 can raise and lower the attached work devices using an actuator such as a hydraulic cylinder.

[0026] The power from engine 3 is shifted by a transmission (not shown) housed in the clutch housing 5a, and then transmitted to the front axle mechanism via the drive transmission shaft 200, and can also be transmitted to the front wheels 6 via the front axle mechanism. The power shifted by the transmission can also be transmitted to the rear wheels 7 via the rear axle mechanism. In this way, the power from engine 3 rotates the front wheels 6 and the rear wheels 7, allowing the tractor 1 to move. The power from engine 3 can also drive the work equipment mounted on the lifting device 9.

[0027] A cabin 10 is located behind the engine 3. The cabin 10 is mounted on the vehicle body (transmission case 5, etc.). Inside the cabin 10, a living space for the driver is formed. A seat 11 for the driver is arranged in the living space. A steering wheel 12 for adjusting the steering angle of the front wheels 6 is located at the front of the cabin 10.

[0028] The front axle case 20 shown in Figures 2 to 4 houses the axle (not shown) of the front wheel 6. The front axle case 20 is positioned below the machine frame 2. The front axle case 20 is formed in an elongated shape in the left-right direction. The front axle case 20 is hollow, and the axle of the front wheel 6 is positioned in the internal space. The front wheel 6 is provided on both sides of the front axle case 20 via axles. The front axle case 20, together with the steering cylinder 31 described later, constitutes the front axle mechanism. The front axle case 20 is equipped with a shaft portion 21.

[0029] The shaft portion 21 shown in Figures 4 and 8 is a part that protrudes forward and backward from the center of the front axle case 20 in the left-right direction. The shaft portion 21 is formed in a substantially cylindrical shape with its axis oriented in the front-rear direction. As shown in Figure 8, of the front and rear shaft portions 21, the rear shaft portion 21 has a through hole 21a that opens to the rear and communicates with the internal space.

[0030] The steering device 30 shown in Figure 2 steers the front wheels 6 according to the amount of steering wheel 12 is operated. The steering device 30 constitutes a power steering mechanism that uses hydraulics to assist steering. The steering device 30 comprises a steering cylinder 31, a steering valve 32, and a first hose 33.

[0031] The steering cylinder 31 shown in Figure 3 changes the steering angle of the front wheels 6 by operating under hydraulic pressure from oil supplied by an appropriate pump (not shown). The steering cylinder 31 is located at the front of the front axle case 20.

[0032] The steering valve 32 supplies oil to the steering cylinder 31 according to the amount of operation of the steering wheel 12. The steering valve 32 is located at the top of the flywheel housing 5c.

[0033] 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.

[0034] As described above, the steering device 30 drives the steering valve 32 according to the amount of movement of the steering wheel 12, thereby supplying oil to the steering cylinder 31 via the first hose 33, and the steering cylinder 31 operates hydraulically. This steers the front wheels 6.

[0035] The suspension device 100 shown in Figures 3 and 4 absorbs vibrations transmitted from the front axle case 20 (front wheel 6) to the machine frame 2. The suspension device 100 supports the front axle case 20 so that it can swing relative to the machine frame 2. The suspension device 100 comprises a support member 110, a swinging member 120, a swing shaft 130, a suspension cylinder 140, an accumulator 150, and a second hose 160.

[0036] The support member 110 shown in Figures 4, 5, 8, and 9 is fixed to the machine frame 2 and supports the pivot shaft 130, which is the pivot center of the front axle case 20 (the axis oriented in the left-right direction).

[0037] The support member 110 is formed primarily in a substantially plate shape with its plate surface oriented vertically. The support member 110 is formed, for example, by casting. As shown in Figures 8 and 12, the support member 110 is fixed to the lower surface of the aircraft frame 2. This positions the support member 110 below the engine 3. The support member 110 comprises a fixing portion 111, a central portion 112, a recess 113, a first support portion 114, and a second support portion 115.

[0038] The fixing portion 111 shown in Figure 5 is the part that is fixed to the lower surface of the aircraft frame 2. The fixing portion 111 constitutes both left and right ends of the support member 110. Holes are formed in the fixing portion 111 through which fasteners for fixing the support member 110 are inserted.

[0039] The central portion 112 constitutes the left-right central part of the support member 110. As shown in Figure 12, the height of the central portion 112 is approximately the same as the height of the fixing portion 111, and it is formed to be raised relative to its surroundings.

[0040] The recess 113 is a portion formed to recess downward between the left and right fixing portions 111 and the central portion 112. In other words, a pair of recesses 113 are provided so as to be located on both the left and right sides of the central portion 112. The recesses 113 are formed to extend in the front-to-back direction.

[0041] The first support portion 114 shown in Figures 5 and 9 is the part that supports the pivot shaft 130. The first support portion 114 is formed in pairs so as to extend downward from both left and right ends (fixing portion 111) of the support member 110. The first support portion 114 is formed in a substantially plate shape with its plate surface oriented in the left and right direction. A hole is formed in the first support portion 114 through which the pivot shaft 130 is inserted.

[0042] The second support portion 115 is a part that supports the pivot shaft 130 together with the first support portion 114. The second support portion 115 is positioned on the left-right central side of the support member 110, at a predetermined distance from 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 formed to be larger than the extension dimension of the first support portion 114 (see Figure 12). The second support portion 115 is formed in a substantially plate shape with its plate surface oriented in the left-right direction. A hole is formed in the second support portion 115 through which the pivot shaft 130 is inserted.

[0043] The oscillating member 120 shown in Figures 4, 6, and 8 supports the front axle case 20 and is pivotably supported relative to the support member 110. The oscillating member 120 is formed, for example, by casting. The oscillating member 120 comprises a main body portion 121, a guide groove portion 122, and a connecting portion 123.

[0044] The main body portion 121 is the part that supports the front axle case 20. The main body portion 121 constitutes the front part of the oscillating member 120. The main body portion 121 is formed in an elongated shape in the front-rear direction. The main body portion 121 has a through hole 121a that penetrates in the front-rear direction. In addition, a recess 121b that opens to the left and right and downward (recesses upward) is formed in the middle of the main body portion 121 in the front-rear direction. As shown in Figure 8, both sides of the recess 121b in the front-rear direction are in communication with the through hole 121a.

[0045] As shown in Figure 8, the front axle case 20 is positioned inside the recess 121b. In this state, the front and rear axle portions 21 of the front axle case 20 are inserted through the through holes 121a. As a result, the front axle case 20 is supported by the main body portion 121 (oscillating member 120) so that it can pivot about the axle portions 21.

[0046] The guide groove 122 is a portion capable of guiding the first hose 33. The guide groove 122 is formed on the upper surface of the main body 121 so as to extend in the front-rear direction. The guide groove 122 is formed on the front-rear central side of the main body 121. The guide groove 122 is formed such that the groove depth dimension decreases as it extends towards the front.

[0047] The connecting portion 123 is the part that is connected to the support member 110 via the pivot shaft 130. The connecting portion 123 constitutes the rear part of the pivot member 120. A pair of connecting portions 123 are formed so as to extend from the rear of the main body portion 121 toward both sides of the support member 110 in the left-right direction (first support portion 114 and second support portion 115). The extending 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 is formed in the extending end of the connecting portion 123 through which the pivot shaft 130 is inserted.

[0048] The pivot shaft 130 shown in Figure 4 is the pivot center of the pivot member 120. The pivot shaft 130 is formed in a substantially cylindrical shape with its axis oriented in the left-right direction. A pair of pivot shafts 130 are provided to connect the left-right sides of the pivot member 120 and the support member 110. The pivot shaft 130 connects the pivot member 120 and the support member 110 by being inserted through the connecting portion 123 of the pivot member 120 and the first support portion 114 and second support portion 115 of the support member 110.

[0049] The suspension cylinder 140 absorbs vibrations through the flow resistance of oil supplied by an appropriate pump (not shown). The suspension cylinder 140 absorbs vibrations by expanding and contracting in the vertical direction. The suspension cylinder 140 is positioned to connect the machine 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 frame 2 around an axis oriented in the left-right direction. The lower end of the suspension cylinder 140 is supported on the side surface of the main body 121 of the oscillating member 120 around an axis oriented in the left-right direction. Furthermore, a pair of suspension cylinders 140 are arranged to connect both the left and right sides of the machine frame 2 and the oscillating member 120.

[0050] The accumulator 150 absorbs vibrations from the suspension cylinder 140. The accumulator 150 is located on the left side of the lower part of the flywheel housing 5c. Two (a pair) of accumulators 150 are provided. One accumulator 150 is connected to the head-side oil chamber of the pair of suspension cylinders 140, and the other accumulator 150 is connected to the rod-side oil chamber of the pair of suspension cylinders 140.

[0051] The second hose 160 connects the pair of suspension cylinders 140 to the pair of accumulators 150. Two second hoses 160 are provided for each suspension cylinder 140.

[0052] The suspension device 100 described above supports the front axle case 20 on the machine frame 2 via a support member 110 and a swinging member 120 so that it can swing around a swing axis 130. In addition, a suspension cylinder 140 interposed between the front axle case 20 (swinging member 120) and the machine frame 2 can absorb vibrations transmitted from the front axle case 20 (front wheel 6) to the machine frame 2.

[0053] The drive transmission shaft 200 shown in Figures 4, 7, and 8 transmits power from the engine 3 (transmission) to the axle in the front axle case 20. As shown in Figure 8, the drive transmission shaft 200 is located below the engine 3 and the clutch housing 5a. The drive transmission shaft 200 is formed in a roughly cylindrical shape with its axis generally oriented in the front-rear direction. The drive transmission shaft 200 comprises a first shaft 210, a second shaft 220, a third shaft 230, a constant velocity joint 240, a spline section 250, a bearing 260, an O-ring 270, and a movement restricting section 280.

[0054] The first shaft 210 shown in Figures 7, 8, and 10 transmits the driving force transmitted from the engine 3 via the transmission. The first shaft 210 constitutes the rear of the drive transmission shaft 200. As shown in Figures 8 and 10, the first shaft 210 is rotatably supported relative to the clutch housing 5a by the shaft support portion 5b at the bottom of the clutch housing 5a. The first shaft 210 is equipped with a transmission-side transmission portion 211 and a toothed portion 212.

[0055] The transmission-side transmission section 211 is the part to which the driving force (rotation) from the power transmission mechanism is transmitted. The transmission-side transmission section 211 is formed in a shape that is enlarged in diameter compared to the rest of the first shaft 210. The transmission-side transmission section 211 is provided at the rear end 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 section 211. As shown in Figures 8 and 10, the transmission-side transmission section 211 is housed inside the shaft support section 5b.

[0056] The teeth 212 shown in Figures 7 and 10 are the parts that engage with the spline portion 250, which will be described later. The teeth 212 are formed on the outer circumferential surface of the front portion of the first shaft 210. The teeth 212 are formed by creating multiple linear grooves extending in the axial direction at equal intervals in the circumferential direction, so that the irregularities are continuous in the circumferential direction. Note that the illustration of the irregularities is omitted in the figures. The portion of the first shaft 210 on which the teeth 212 are formed is reduced in diameter compared to the other portions.

[0057] The second shaft 220, shown in Figures 7, 8, and 10, transmits the driving force from the first shaft 210. The second shaft 220 is positioned in front of the first shaft 210 and constitutes the intermediate portion of the drive transmission shaft 200 in the longitudinal direction. The length of the second shaft 220 is larger than that of the first shaft 210. The rear end of the second shaft 220 is located behind the flywheel housing 5c ​​(see Figure 8). In this embodiment, the rear end of the second shaft 220 is positioned to overlap with the clutch housing 5a in a plan view. The second shaft 220 is equipped with teeth 221.

[0058] The tooth portion 221 is the part that engages with the spline portion 250, which will be described later. The tooth portion 221 is formed on the outer circumferential surface of the rear portion of the second shaft 220, similar to the tooth portion 212, with irregularities that are continuous in the circumferential direction. The portion of the second shaft 220 on which the tooth portion 221 is formed is reduced in diameter compared to the other portions.

[0059] The third shaft 230, shown in Figures 7 and 8, transmits the driving force received from the second shaft 220 to the axle (not shown) of the front wheel 6. The third shaft 230 is positioned in front of the second shaft 220 and constitutes the front part of the drive transmission shaft 200. The length of the third shaft 230 is smaller than that of the second shaft 220.

[0060] As shown in Figure 8, the third shaft 230 is inserted through the through hole 121a of the oscillating member 120 and is rotatably supported relative to the oscillating member 120 (main body portion 121). The front end of the third shaft 230 is inserted through the insertion hole 21a of the front axle case 20. The third shaft 230 is equipped with an axle-side transmission portion 231.

[0061] The axle-side transmission unit 231 is the part that transmits driving force (rotation) to the axle of the front wheel 6. The axle-side transmission unit 231 is provided at the front end of the third shaft 230. As shown in Figure 8, the axle-side transmission unit 231 is located within the space inside the front axle case 20. A gear that engages with the axle (for example, a bevel gear) can be used as the axle-side transmission unit 231.

[0062] The constant velocity joint 240 shown in Figures 7 and 8 flexibly connects the front end of the second shaft 220 and the rear end of the third shaft 230. More specifically, the constant velocity joint 240 transmits torque from the second shaft 220 to the third shaft 230 so that each shaft rotates at a constant speed, even when there is an angle between the second shaft 220 and the third shaft 230.

[0063] The constant velocity joint 240 is formed with an enlarged diameter relative to 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 positioned at a location corresponding to the pivot axis 130. Specifically, the constant velocity joint 240 is positioned such that the part that forms the center of the bend roughly coincides with (overlaps with) the axis of the pivot axis 130 in a side view (see Figure 8).

[0064] The spline portion 250 shown in Figures 7, 8, and 10 connects the front end of the first shaft 210 and the rear end of the second shaft 220, allowing relative movement of the first shaft 210 and the second shaft 220 in the axial direction (front-rear direction). The spline portion 250 is formed in a substantially cylindrical shape that allows insertion of the front end of the first shaft 210 and the rear end of the second shaft 220. 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 equipped with teeth 251.

[0065] The teeth 251 are the parts that engage with the teeth 212 of the first shaft 210 and the teeth 221 of the second shaft 220. The teeth 251 are formed on the inner circumferential surface of the spline portion 250 such that the irregularities are continuous in the circumferential direction.

[0066] By engaging the teeth 251 of the spline portion 250 described above with the teeth 212 of the first shaft 210 and the teeth 221 of the second shaft 220, the first shaft 210 and the second shaft 220 can be connected by a spline structure. This allows the first shaft 210 and the second shaft 220 to be connected in such a way that relative movement in the axial direction (forward and backward direction) is permitted, while relative movement in the rotational direction (circumferential direction) is restricted.

[0067] The bearings 260 shown in Figures 8 and 10 support each shaft of the drive transmission shaft 200 so that it can rotate smoothly. For example, ball bearings can be used as the bearings 260. As shown in Figure 8, in this embodiment, a pair of bearings 260 (first shaft side bearing 260A) are provided between the shaft support portion 5b of the clutch housing 5a and the first shaft 210, spaced apart in the front-rear direction. In addition, a pair of bearings 260 (third shaft side bearing 260B) are provided between the through hole 121a of the oscillating member 120 (main body portion 121) and the third shaft 230, spaced apart in the front-rear direction.

[0068] The O-ring 270 shown in Figure 10 closes (seals) the gap between the inner circumferential surface of the spline portion 250 and the outer circumferential surfaces of the front end of the first shaft 210 and the rear end of the second shaft 220. The O-ring 270 is made of a flexible material such as rubber. The O-rings 270 are provided on both the front and rear sides of the inner circumferential surface of the spline portion 250. In the illustrated example, the rear O-ring 270 is provided in a groove formed at the rear end of the inner circumferential surface of the spline portion 250, and the front O-ring 270 is provided in a groove formed on the outer circumferential surface of the second shaft 220.

[0069] By providing the O-ring 270, leakage of lubricant (grease, etc.) sealed between the inner circumferential surface of the spline portion 250 and the outer circumferential surfaces of the first shaft 210 and the second shaft 220 can be suppressed, thereby reducing the burden of maintenance.

[0070] The movement restricting portion 280 shown in Figures 8 and 10 restricts the axial movement of the spline portion 250. The movement restricting portion 280 is fixed to the outer circumferential surface of the second shaft 220. In the example shown in Figure 10, the movement restricting portion 280 is engaged with a groove formed on the outer circumferential surface of the second shaft 220, forward of the groove where the O-ring 270 is provided. The movement restricting portion 280 can be, for example, a retaining ring. The movement restricting portion 280 is designed to be released from engagement with the groove on the outer circumferential surface by expanding its diameter. Furthermore, the movement restricting portion 280 can move back and forth on the second shaft 220 when expanded (see Figure 11).

[0071] As shown in Figures 8 and 10, the spline portion 250 is positioned between the shaft support portion 5b of the clutch housing 5a and the movement restricting portion 280, thereby restricting its forward and backward movement. The second shaft 220, to which the movement restricting portion 280 is fixed, is restricted from moving backward when the movement restricting portion 280 is in contact with the spline portion 250 (see Figures 8 and 10). Furthermore, the second shaft 220 is restricted from moving forward when the constant velocity joint 240 connected to its front end is in contact with the rear end of the main body portion 121 (rocking member 120) (for example, an oil seal provided in the through hole 121a) (see Figure 8). A certain amount of space (for example, about 1 mm) is formed between the movement restricting portion 280 and the spline portion 250, and between the main body portion 121 and the constant velocity joint 240. Thus, the second shaft 220 is connected to the first shaft 210 via the spline portion 250 so that it is permitted to move in the front-rear direction (axial direction) within the range of the above-mentioned gap.

[0072] In the following, the position of the spline portion 250 connecting the front end of the first shaft 210 and the rear end of the second shaft 220, as described above, will be referred to as the "connection position" (see Figure 10). In this embodiment, the spline portion 250 at the connection position can be moved forward (towards the second shaft 220) to a "disconnection position" that releases the connection with the first shaft 210 (see Figure 11). In this case, the movement restricting portion 280 is moved forward to allow the spline portion 250 to move forward. As shown in Figure 11, the movement restricting portion 280 that has moved forward is positioned to fit into a recessed (constricted) portion on the outer circumferential surface of the second shaft 220. At this time, the shaft cover portion 310, which will be described later, is removed.

[0073] Figure 11 shows the spline section 250 in the disconnected position. In the disconnected position, the front-to-back positions of the rear end of the second shaft 220 and the rear end of the spline section 250 are roughly 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. Conversely, 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 section 250 to the connection position.

[0074] The cover member 300 shown in Figure 8 covers the drive transmission shaft 200 from below. The cover member 300 is formed by bending a metal plate as appropriate. The cover member 300 is positioned to span the shaft support portion 5b of the clutch housing 5a and the support member 110. The cover member 300 comprises a shaft cover portion 310 and a joint cover portion 320.

[0075] 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 bottom of the first shaft 210, the second shaft 220, and the spline portion 250. The shaft cover portion 310 is formed in a roughly box shape that is elongated in the front-rear direction. The rear end of the shaft cover portion 310 is fixed to the shaft support portion 5b.

[0076] The joint cover portion 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 portion 320 covers both the left and right sides and the bottom of the constant velocity joint 240. The rear end of the joint cover portion 320 is fixed to the shaft cover portion 310. In addition, both the left and right sides of the joint cover portion 320 are fixed to the second support portion 115 of the support member 110 (see Figure 9).

[0077] An opening 321 is formed on the side of the joint cover portion 320, which opens in the left-right direction and communicates with the interior of the joint cover portion 320. The opening 321 is formed at the rear lower corner of the side of the joint cover portion 320. Foreign matter (such as mud or water) that has entered the interior of the joint cover portion 320 can be discharged through the opening 321.

[0078] As described above, the tractor 1 is equipped with a constant velocity joint 240 on the drive transmission shaft 200, which allows the drive transmission shaft 200 to bend in accordance with the operation of the suspension device 100 (oscillation around the oscillating shaft 130) (see Figure 8).

[0079] In this case, if assembly errors occur in the constant velocity joint 240, and the part of the constant velocity joint 240 that forms the center of bending does not coincide with the axis of the pivot shaft 130 in a side view, the drive transmission shaft 200 may not be able to follow the movement of the suspension device 100.

[0080] Therefore, in this embodiment, in addition to the constant velocity joint 240, the first shaft 210 and the second shaft 220 are connected in a spline structure using a spline section 250. As a result, as shown in Figure 10, relative movement in the axial direction of the first shaft 210 and the second shaft 220 is permitted, and assembly errors of the constant velocity joint 240 can be absorbed.

[0081] Furthermore, as in this embodiment, when the first shaft 210 and the second shaft 220 are connected by a spline structure, a certain amount of gap formed between the outer surface of the second shaft 220 and the inner surface of the spline portion 250 allows for radial displacement (vertical movement, etc.) of the second shaft 220 relative to the spline portion 250 (resulting in some play). In this embodiment, by making the second shaft 220 relatively long, the amount of displacement of the front end side (constant velocity joint 240 side) of the second shaft 220 in accordance with the amount of play displacement of the spline portion 250 can be increased. This makes it possible to more effectively absorb assembly errors of the constant velocity joint 240.

[0082] Thus, in this embodiment, by employing a spline structure to connect the first shaft 210 and the second shaft 220, the assembly errors in the axial and radial directions of the drive transmission shaft 200 can be absorbed. Furthermore, with this configuration, unlike, for example, the case in which another constant velocity joint 240 is provided on the drive transmission shaft 200 to absorb assembly errors, space can be saved below the vehicle body. This ensures the minimum ground clearance of the vehicle body.

[0083] Furthermore, the tractor 1 described above allows for the convenient routing of hoses (first hose 33 and second hose 160) for operating the steering device 30 and the suspension device 100. The routing of each hose will be described below.

[0084] In this embodiment, as shown in Figure 12, a routing space A is formed between the engine 3 and the support member 110, through which each hose (first hose 33 and second hose 160) can be routed. The routing space A includes a first routing space A1 and a second routing space A2.

[0085] The first routing space A1 is the space in which the first hose 33 of the steering device 30 is routed. The first routing space A1 is partitioned by the recess 3b of the engine 3 and the central part 112 of the support member 110. The first routing space A1 is formed to extend in the front-rear direction.

[0086] The first hose 33, connected to the steering valve 32 at the rear of the engine 3, passes through the first routing space A1. The first hose 33 is positioned to extend front to back over the central portion 112 of the support member 110 (see Figure 3). In this embodiment, the first hose 33, having passed through the first routing space A1, is guided forward along the guide groove 122 of the oscillating member 120 and connected to the steering cylinder 31.

[0087] The second routing space A2 is the space in which the second hose 160 is routed. The second routing space A2 is demarcated by the left and right sides of the engine 3 (oil pan 3a), the inner surfaces of the machine frame 2 facing those sides, and a pair of recesses 113 of the support member 110. The second routing space A2 is formed in pairs so as to be located on both the left and right sides of the first routing space A1. The second routing space A2 is formed to extend in the front-rear direction.

[0088] The left and right second hoses 160, connected to the accumulator 150 at the rear of engine 3, pass through the left and right second routing spaces A2 and connect to the left and right suspension cylinders 140 (see Figure 3).

[0089] As described above, in this embodiment, the routing space A formed between the engine 3 and the support member 110 can be used to route the first hose 33 and the second hose 160. Furthermore, by using the support member 110 of the suspension device 100 as a guide for the first hose 33 and the second hose 160, the number of components can be reduced. In addition, since the support member 110 is interposed between each hose and the drive transmission shaft 200 (constant velocity joint 240, etc.), direct contact between the high-speed rotating drive transmission shaft 200 and each hose can be prevented.

[0090] Here, the tractor 1 is provided with a suspension system 100, but a specification without the suspension system 100 is also conceivable. If the suspension system 100 is not provided, the mechanism for swinging the drive transmission shaft 200 up and down becomes unnecessary, and the drive transmission shaft 200 can be positioned at a higher position. In this case, it is also possible to place the drive transmission shaft 200 in the recess 3b (first routing space A1) of the oil pan 3a of the engine 3 instead of the first hose 33. In this way, the engine 3 is made highly versatile in this embodiment.

[0091] In this embodiment, the first hose 33 can be routed using the recess 3b of the engine 3 as described above. Furthermore, it is assumed that the first hose 33 moves up and down and left and right in conjunction with the operation of the front axle case. According to this embodiment, such a first hose 33 can be stably routed using the first routing space A1 on the left-right central side of the vehicle body and the guide groove 122.

[0092] Furthermore, in this embodiment, the second routing spaces A2 formed on both the left and right sides of the first hose 33 can be used to suitably route the second hoses 160 of the suspension cylinders 140, which are located on both the left and right sides of the vehicle body.

[0093] As described above, the tractor 1 (work vehicle) according to this embodiment is The aircraft frame 2 to which engine 3 is fixed, A front axle case 20 that supports the axle of the front wheel 6, A suspension device 100 supports the front axle case 20 so that it can pivot around the pivot axis 130 relative to the machine frame 2, A first shaft 210 is located at the bottom of the first case (clutch housing 5a) that houses the transmission, and the driving force transmitted from the engine 3 via the transmission is transmitted to it. A second shaft 220 is positioned in front of the first shaft 210 and to which the driving force from the first shaft 210 is transmitted, A third shaft 230 is positioned in front of the second shaft 220 and transmits the driving force transmitted from the second shaft 220 to the axle. A constant velocity joint 240 connects the front end of the second shaft 220 and the rear end of the third shaft 230 so as to be bendable at a position corresponding to the pivot axis 130, A connecting portion (spline portion 250) is provided to connect the rear end of the second shaft 220 and the front end 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 features.

[0094] This configuration allows for the absorption of assembly errors in the constant velocity joint 240 and also saves space. Specifically, when a suspension device 100 is provided that supports the front axle case 20 so as to be able to swing around the pivot axis 130, a constant velocity joint 240 that can bend at a position corresponding to the pivot axis 130 must be provided on the shaft, and the shaft must be bent to follow the movement of the suspension device 100. However, if assembly errors occur in the constant velocity joint 240, the shaft may 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 connecting part (spline part 250) that allows relative movement of the first shaft 210 and the second shaft 220 in the axial direction, thereby absorbing the assembly errors of the constant velocity joint 240. Furthermore, when using the connection portion (spline portion 250) described above, unlike when another constant velocity joint 240 is provided to absorb the assembly error, space can be saved below the vehicle body. This ensures the minimum ground clearance of the vehicle body.

[0095] Furthermore, the rear end of the second shaft 220 is It is positioned between the engine 3 and the first case (clutch housing 5a), and is located behind the second case (flywheel housing 5c) that houses the flywheel.

[0096] By configuring it in this way, assembly errors of the constant velocity joint 240 can be absorbed more effectively. That is, when a connection by a connecting part (spline part 250) is adopted, a certain amount of gap formed between the second shaft 220 and the connecting part (spline part 250) allows for radial displacement (vertical movement, etc.) of the second shaft 220 relative to the connecting part (spline part 250) (play occurs). In this embodiment, by positioning the rear end of the second shaft 220 behind the flywheel housing 5c, the length dimension of the second shaft 220 is made relatively large. By making the second shaft 220 relatively long in this way, the amount of displacement of the front end side (constant velocity joint 240 side) of the second shaft 220 in accordance with the amount of play displacement of the connecting part (spline part 250) can be increased. As a result, assembly errors of the constant velocity joint 240 can be absorbed more effectively.

[0097] Furthermore, the aforementioned connection portion (spline portion 250) A connection position connecting the rear end of the second shaft 220 and the front end of the first shaft 210, From the aforementioned connection position, move toward the first shaft 210 side or the second shaft 220 side to a disconnection position in which the connection between the first shaft 210 and the second shaft 220 is released, It is displaceable.

[0098] This configuration improves ease of assembly. Specifically, by setting the connecting portion (spline portion 250) to the disconnected position, the second shaft 220 can be easily attached to and detached from the first shaft 210, thereby improving ease of assembly.

[0099] Furthermore, the aforementioned connection portion (spline portion 250) The second shaft 220 and the first shaft 210 are connected by a spline structure in which a first engaging portion (tooth portion 251) formed on the inner circumferential surface engages with a second engaging portion (tooth portion 212, tooth portion 221) formed on the outer circumferential surface of the rear end side of the second shaft 220 and the front end side of the first shaft 210.

[0100] By configuring it in this way, the spline structure connects the second shaft 220 and the first shaft 210, which allows for more effective absorption of assembly errors in the constant velocity joint 240.

[0101] Furthermore, on both sides in the front-rear direction of the inner circumferential surface of the connecting portion (spline portion 250), a closing portion (O-ring 270) is provided to close the gap 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.

[0102] This configuration improves maintainability. Specifically, it is possible to suppress leakage of lubricant (grease, etc.) sealed between the inner circumferential surface of the connecting 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.

[0103] Furthermore, the constant velocity joint 240 is covered from below by a cover portion (joint cover portion 320) which has a discharge portion (opening 321) formed therein that allows foreign matter that has entered the interior to be discharged.

[0104] With this configuration, even if foreign matter enters the inside of the cover portion (joint cover portion 320), the foreign matter can be discharged.

[0105] Furthermore, the tractor 1 (work vehicle) according to this embodiment is The aircraft frame 2 to which engine 3 is fixed, A front axle case 20 that supports the front wheel axle and is pivotable around a pivot axis 130, A damping device (suspension device 100) that absorbs vibrations transmitted from the front axle case 20 to the machine frame 2, A support member 110 is fixed to the aircraft frame 2 so as to be located below the engine 3 and supports the pivot shaft 130, and between it and the engine 3, it defines a routing space A through which linear members (first hose 33, second hose 160) extending in the front-rear direction can be routed, It is equipped with the following features.

[0106] This configuration allows for efficient routing of the linear members (first hose 33, second hose 160). Specifically, the routing space A formed between the engine 3 and the support member 110 can be used to route the linear members (first hose 33, second hose 160). Furthermore, by using the support member 110, which supports the pivot shaft 130, as a guide for the linear members (first hose 33, second hose 160), the number of components can be reduced.

[0107] Furthermore, the engine 3 is It has a recess 3b formed on the lower surface that extends in the front-to-back direction, The aforementioned routing space A is It includes a first routing space A1 that is partitioned by the recess 3b and the support member 110.

[0108] With this configuration, the recess 3b formed on the underside of the engine 3 can be used to route the linear member (first hose 33). Furthermore, depending on the model and type of tractor (work vehicle), the recess 3b (first routing space A1) can also be used as a space for arranging the drive transmission shaft 200.

[0109] Furthermore, the linear members (first hose 33, second hose 160) are From the rear side of the engine 3, a first hose 33 is connected to the steering cylinder provided in the front axle case 20, The first hose 33 is routed into the first routing space A1.

[0110] This configuration allows for efficient routing of the first hose 33. By routing the first hose 33 into the first routing space A1 formed by the recess 3b, the first hose 33, which moves up and down in conjunction with the operation of the front axle case 20, can be routed stably.

[0111] Furthermore, the aforementioned routing space A is The second routing 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.

[0112] By configuring it in this way, the linear member (second hose 160) can be routed using the second routing space A2 formed on the side of the engine 3.

[0113] Furthermore, the shock absorber (suspension device 100) is, It is equipped with a shock absorber cylinder (suspension cylinder 140), The aforementioned linear members (first hose 33, second hose 160) From the rear side of the engine 3, a second hose 160 is connected to the buffer cylinder (suspension cylinder 140), The second hose 160 is routed into the second routing space A2.

[0114] This configuration allows for efficient routing of the second hose 160. Specifically, the second hose 160 can be routed using the second routing space A2 located to the side of the engine 3.

[0115] Furthermore, the front axle case 20 is fixed to the support member 110 and is supported by a pivoting member 120 that is pivotable around the pivot axis 130. The aforementioned rocking member 120 is It has a guide groove 122 formed on its upper surface that extends in the front-rear direction and is capable of guiding the linear members (first hose 33, second hose 160).

[0116] With this configuration, the guide groove 122 formed on the upper surface of the oscillating member 120 can be used to route the linear members (first hose 33, second hose 160).

[0117] Furthermore, a drive transmission shaft 200 is positioned below the support member 110 to transmit the driving force from the engine 3 to the axle.

[0118] This configuration protects the linear members (first hose 33, second hose 160). Specifically, by interposing the support member 110 between the drive transmission shaft 200 and the linear members (first hose 33, second hose 160), direct contact between the high-speed rotating drive transmission shaft 200 and the linear members (first hose 33, second hose 160) can be prevented.

[0119] Furthermore, it includes a cover portion (joint cover portion 320) that is fixed to the support member 110 and covers the drive transmission shaft 200 from below.

[0120] By configuring it in this way, the cover portion (joint cover portion 320) that covers the drive transmission shaft 200 can be fixed using the support member 110.

[0121] Furthermore, the tractor 1 according to this embodiment is one form of the work vehicle according to the present invention. Furthermore, the clutch housing 5a according to this embodiment is one form of the first case according to the present invention. Furthermore, the flywheel housing 5c ​​according to this embodiment is one embodiment of the second case according to the present invention. Furthermore, the spline portion 250 according to this embodiment is one form of the connecting portion according to the present invention. Furthermore, the tooth portion 251 according to this embodiment is one form of the first engaging portion according to the present invention. Furthermore, the teeth 212 and 221 according to this embodiment are one form of the second engaging portion according to the present invention. Furthermore, the O-ring 270 according to this embodiment is one form of the closing part according to the present invention. Furthermore, the joint cover portion 320 according to this embodiment is one form of the cover portion according to the present invention. Furthermore, the suspension device 100 according to this embodiment is one form of the shock absorber according to the present invention. Furthermore, the first hose 33 and the second hose 160 according to this embodiment are forms of the linear member according to the present invention. Furthermore, the suspension cylinder 140 according to this embodiment is one form of the cushioning cylinder according to the present invention. Furthermore, the opening 321 according to this embodiment is one form of the discharge section according to the present invention.

[0122] 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 as described in the claims.

[0123] For example, the shapes of each component (support member 110, oscillating member 120, drive transmission shaft 200, etc.) described in the above embodiment are merely examples and are not limited to the shapes described above. The shapes of each component can be changed to any shape.

[0124] Furthermore, although the above embodiment shows an example in which the rear end of the second shaft 220 is positioned behind the flywheel housing 5c, the embodiment is not limited to this configuration. 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).

[0125] Furthermore, in the above embodiment, the transmission case 5, clutch housing 5a, flywheel housing 5c, etc., are given as examples of members that house the power transmission mechanism that transmits power from the engine 3, but the embodiment is not limited to this. For example, the transmission case 5, etc., can be formed integrally with each other, or they can be further divided.

[0126] Furthermore, in the above embodiment, an example was shown in which the spline portion 250 was moved forward (towards the second shaft 220) when the connection between the first shaft 210 and the second shaft 220 was released, but the embodiment is not limited to this configuration. For example, the connection between each shaft may be released by moving the spline portion 250 backward (towards the first shaft 210). In this case, the length dimensions of the first shaft 210 and other dimensions are appropriately set so that the spline portion 250 can be moved backward. Specifically, the length dimensions of the first shaft 210 and the spline portion 250 can be set so as to ensure sufficient movement distance for the spline portion 250.

[0127] Furthermore, although the above embodiment shows an example in which the spline portion 250 is movable between a connected position and a disconnected position, the embodiment is not limited to this, and for example, the movement may be made impossible.

[0128] Furthermore, although the above embodiment shows an example in which a pair of second wiring spaces A2 are provided on the left and right sides, the embodiment is not limited to this configuration, and for example, one second wiring space A2 may be provided.

[0129] Furthermore, although the above embodiment shows an example in which the rocking member 120 is provided with a guide groove 122, the embodiment is not limited to this configuration, and for example, the guide groove 122 may be omitted.

[0130] Furthermore, although the above embodiment shows an example in which hoses (first hose 33 and second hose 160) connected to the cylinder are routed using the routing space A, the embodiment is not limited to this configuration. For example, other linear members such as harnesses and wires may be routed in the routing space A.

[0131] Furthermore, although a tractor 1 was used as an example of a work vehicle in the above embodiment, the embodiment is not limited to this. For example, the work vehicle may be other agricultural vehicles, construction vehicles, industrial vehicles, etc. [Explanation of Symbols]

[0132] 1 tractor 20 Front axle case 100 Suspension System 200 Drive transmission shaft 300 Cover component

Claims

1. The aircraft frame to which the engine is fixed, A front axle case that supports the front wheel axle and is pivotable around the pivot axis, A damping device that absorbs vibrations transmitted from the front axle case to the machine frame, A support member is fixed to the aircraft frame so as to be located below the engine and supports the pivot shaft, and between it and the engine, a routing space is provided in which a linear member extending in the front-rear direction is routed; It is equipped with, The aforementioned engine is It has a recess formed on its lower surface that extends in the front-to-back direction, The aforementioned routing space is The first routing space is defined by the recess and the support member, The aforementioned support member is The raised portion is formed to protrude towards the recess at a position opposite to the recess, and the linear member is positioned between it and the recess so as to extend front to back. Work vehicle.

2. The linear member is, From the rear side of the engine, a first hose is connected to the steering cylinder provided on the front axle case, The first hose is routed in the first routing space. The work vehicle according to claim 1.

3. The aforementioned routing space is The second routing space is partitioned by the side surface of the engine, the inner surface of the aircraft frame facing the side surface, and the support member. The work vehicle according to claim 1.

4. The aforementioned buffer device, Equipped with a buffer cylinder, The linear member is, From the rear side of the engine, including a second hose connected to the buffer cylinder, The second hose is routed in the second routing space. The work vehicle according to claim 3.

5. The front axle case is fixed to the aforementioned front axle case and comprises a pivoting member that is supported by the support member so as to be pivotable around the pivot axis, The rocking member is, It has a guide groove formed on its upper surface so as to extend in the front-rear direction, which can guide the linear member. The work vehicle according to claim 1.

6. Below the support member, a drive transmission shaft is positioned to transmit the driving force from the engine to the axle. A work vehicle according to any one of claims 1 to 5.

7. It is fixed to the support member and comprises a cover portion that covers the drive transmission shaft from below, The work vehicle according to claim 6.

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