Work vehicle

Abstract

To stably regulate a lateral movement of a cabin by a lateral rod, in a work vehicle in which the cabin is supported by a machine body through a suspension mechanism.SOLUTION: A work vehicle includes: a cabin 10 housing a driving unit; right and left suspension mechanisms 24 supporting right and left parts of the cabin 10 on a machine body; and right and left lateral rods 25 that allow a vertical movement of the cabin 10 relative to the machine body and regulates a horizontal movement of the cabin 10 relative to the machine body. The right lateral rod 25 is disposed on a right lateral outer side with respect to the right suspension mechanism 24 and is connected to a right part of the cabin 10. The left lateral rod 25 is disposed on a left lateral outer side with respect to the left suspension mechanism 24 and is connected to a left part of the cabin 10.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a work vehicle provided with a cabin that houses a driver's section in which a worker rides. [Background technology]

[0002] In a tractor, which is an example of a work vehicle, as disclosed in Patent Document 1, there is a tractor configured so that the cabin is supported on the vehicle body via right and left suspension mechanisms. In Patent Document 1, a lateral rod is connected between the aircraft body and the cabin, and the lateral rod allows the cabin to move up and down relative to the aircraft body and restricts the cabin from moving left and right relative to the aircraft body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5394124 Summary of the Invention [Problem to be solved by the invention]

[0004] In a work vehicle, the cabin that houses the driver's seat has a relatively large width, so when the cabin is supported on the vehicle body via a suspension mechanism, there is room for improvement in terms of stabilizing the lateral rod's regulation of the cabin's left and right movement.

[0005] The present invention aims to provide a configuration in which the lateral rods can stably regulate the left and right movement of the cabin in a work vehicle in which the cabin is supported on the body via a suspension mechanism. [Means for solving the problem]

[0006] The work vehicle of the present invention is provided with a driver's section in which a worker rides, a cabin that houses the driver's section, right and left suspension mechanisms that support the right and left sections of the cabin on the vehicle body, and right and left lateral rods that allow the cabin to move up and down relative to the vehicle body and restrict the cabin's movement to the left and right relative to the vehicle body, the right lateral rod being disposed laterally outward of the right suspension mechanism and connected to the right section of the cabin, and the left lateral rod being disposed laterally outward of the left suspension mechanism and connected to the left section of the cabin. The vehicle is equipped with a link mechanism that is mounted on the rear of the vehicle body so as to be able to swing up and down and extends rearward to support a working device, a lift arm that is mounted on the rear of the vehicle body so as to be able to swing up and down and operates to raise and lower the link mechanism, and a lift cylinder that is connected between the vehicle body and the lift arm and operates to raise and lower the lift arm, the right suspension mechanism is positioned laterally outward to the right of the lift arm and the lift cylinder and supports the right side of the rear of the cabin, and the left suspension mechanism is positioned laterally outward to the left of the lift arm and the lift cylinder and supports the left side of the rear of the cabin.

[0007] According to the present invention, when the cabin is supported on the aircraft body via right and left suspension mechanisms, right and left lateral rods are provided, so that the lateral rods can stably regulate the left and right movement of the cabin even in the case of a cabin with a relatively large width.

[0008] According to the present invention, when right and left lateral rods are provided, the right lateral rod is positioned laterally outward of the right suspension mechanism and connected to the right part of the cabin, and the left lateral rod is positioned laterally outward of the left suspension mechanism and connected to the left part of the cabin. This allows the right and left lateral rods to be positioned apart from each other in the left-right direction, which is advantageous in terms of stabilizing the restriction of left-right movement of the cabin by the lateral rods. In a work vehicle such as a tractor, a link mechanism for supporting a work implement is sometimes provided at the rear of the vehicle body and extends rearward. A lift arm for raising and lowering the link mechanism is provided at the rear of the vehicle body, and a lift cylinder is connected between the vehicle body and the lift arm. The lift arm is raised and lowered by the lift cylinder, thereby raising and lowering the link mechanism (work implement). According to the present invention, the right (left) suspension mechanism is disposed laterally outward on the right (left) side of the lift arm and the lift cylinder to support the right (left) rear part of the cabin. As a result, the right and left suspension mechanisms are arranged apart from each other in the left-right direction, so that the cabin is stably supported by the right and left suspension mechanisms. According to the present invention, the right (left) lateral rod is disposed laterally outward of the right (left) suspension mechanism and is disposed laterally outward of the right (left) lift arm and lift cylinder. This makes it possible to avoid interference between the lateral rod and the lift arm and lift cylinder.

[0009] In the present invention, it is preferable that the right and left suspension mechanisms are set so that when an operator is not riding in the driver's unit, the right lateral rod extends diagonally downward from the right part of the cabin to the right outer side, and when an operator is not riding in the driver's unit, the left lateral rod extends diagonally downward from the left part of the cabin to the left outer side, and when an operator is riding in the driver's unit, the right and left lateral rods are in a position close to horizontal.

[0010] According to the present invention, when an operator gets on the operator's section, the suspension mechanism contracts slightly due to the operator's weight, and the right and left lateral rods assume a nearly horizontal position. When the suspension mechanism expands or contracts in this state, the lateral rods swing up and down from a nearly horizontal position, which is advantageous in terms of stabilizing the regulation of left and right movement of the cabin by the lateral rods.

[0011] In the present invention, it is preferable that a right elastic body be provided in the right suspension mechanism and determine the limit of contraction operation of the right suspension mechanism, and a left elastic body be provided in the left suspension mechanism and determine the limit of contraction operation of the left suspension mechanism.

[0012] According to the present invention, when the right (left) part of the cabin descends relative to the aircraft body and the right (left) suspension mechanism contracts, the right (left) elastic body that determines the limit of contraction of the right (left) suspension mechanism can restrict the right (left) part of the cabin from descending more than necessary. In this case, the right (left) elastic body elastically deforms to restrict the lowering of the right (left) part of the cabin, so shocks are less likely to occur, resulting in a comfortable ride for the operator in the driving section.

[0013] In the present invention, it is preferable to provide a right rebound spring that is provided in the right suspension mechanism and provides resistance to the extension operation of the right suspension mechanism but not to the contraction operation of the right suspension mechanism, and a left rebound spring that is provided in the left suspension mechanism and provides resistance to the extension operation of the left suspension mechanism but not to the contraction operation of the left suspension mechanism.

[0014] Operators in the driver's compartment rarely feel uneasy about the lowering operation of the right (left) part of the cabin (the contraction operation of the right (left) suspension mechanism), but they may feel uneasy about the raising operation of the right (left) part of the cabin (the extension operation of the right (left) suspension mechanism).

[0015] According to the present invention, by providing a rebound spring in the suspension mechanism, the right (left) part of the cabin becomes less likely to rise (the right (left) suspension mechanism becomes less likely to extend), resulting in a more comfortable ride for the operator in the driving section. By making it more difficult for the right (left) part of the cabin to rise (by making it more difficult for the right (left) suspension mechanism to extend), the rolling action of the cabin relative to the aircraft body is also suppressed, resulting in a more comfortable ride for the operators in the driving section.

[0016]

[0017]

[0018]

[0019]

[0020] In the present invention, it is preferable that right and left rear axle cases are provided that extend outward from the rear of the body to the right and left sides and support right and left running gear, and that the right lateral rod is connected between the right part of the rear of the cabin and the right rear axle case, and that the left lateral rod is connected between the left part of the rear of the cabin and the left rear axle case.

[0021] In some work vehicles such as tractors, right and left rear axle cases are provided that extend outward from the rear of the vehicle body to the right and left sides, and the right and left running gear (e.g., rear wheels and crawler running gear) are supported by the rear axle cases.

[0022] According to the present invention, the right (left) lateral rod is connected between the right (left) part of the rear of the cabin and the right (left) rear axle case, and the lateral rod is connected to the fuselage via the rear axle case. By effectively utilizing the rear axle case that extends outward from the fuselage to the right (left) side, the right (left) lateral rod can be comfortably positioned outward to the right (left) side relative to the right (left) suspension mechanism, and can also be comfortably positioned outward to the right (left) side relative to the lift arm and lifting cylinder.

[0023] In the present invention, it is preferable that the right portion of the right lateral rod enters the right running device so that the right portion of the right lateral rod overlaps with the right running device when viewed from behind, and that the left portion of the left lateral rod enters the left running device so that the left portion of the left lateral rod overlaps with the left running device when viewed from behind.

[0024] According to the present invention, when the right (left) lateral rod is connected to the right (left) rear axle case, the right portion (left portion) of the right (left) lateral rod enters the right (left) running gear. This makes it possible to easily obtain long lateral rods, which is advantageous in terms of stabilizing the regulation of left and right movement of the cabin by the lateral rods.

[0025] According to the present invention, the right portion (left portion) of the right (left) lateral rod enters the right (left) traveling device, so that the right portion (left portion) of the right (left) lateral rod is covered by the right (left) traveling device, making it difficult for mud, soil, etc. to adhere to the right portion (left portion) of the right (left) lateral rod. This reduces the likelihood of the lateral rod's operation being hindered by the adhesion of mud, soil, etc., which is advantageous in terms of stabilizing the regulation of the left and right movement of the cabin by the lateral rod.

[0026] In the present invention, it is preferable that the right lateral rod is arranged between the cabin and the right suspension mechanism in a side view, and the left lateral rod is arranged between the cabin and the left suspension mechanism in a side view.

[0027] According to the present invention, when the right (left) suspension mechanism supports the right (left) rear part of the cabin, the right (left) lateral rod is disposed between the cabin and the right (left) suspension mechanism. This allows the lateral rods to be arranged by effectively utilizing the space between the cabin and the suspension mechanism, thereby saving space for arranging the lateral rods.

[0028] In the present invention, it is preferable that the right suspension mechanism is connected between the right part of the rear of the cabin and the right rear axle case, and the left suspension mechanism is connected between the left part of the rear of the cabin and the left rear axle case.

[0029] According to the present invention, the right (left) suspension mechanism is connected across the right (left) part at the rear of the cabin and the right (left) rear axle case, and the suspension mechanism is connected to the fuselage via the rear axle case. By effectively utilizing the rear axle case that extends outward from the fuselage to the right (left) side, the right (left) suspension mechanism can be comfortably positioned outward to the right (left) side relative to the lift arm and lifting cylinder.

[0030] In the present invention, it is preferable that right and left support members are provided attached to the right and left rear axle cases, the right suspension mechanism and the right lateral rod are connected to the right support member, and the left suspension mechanism and the left lateral rod are connected to the left support member.

[0031] According to the present invention, the suspension mechanism and the lateral rod are connected to the rear axle case via a common support member, which means that the support member is used both as a member for connecting the suspension mechanism to the rear axle case and as a member for connecting the lateral rod to the rear axle case, which is advantageous in terms of simplifying the structure.

[0032] In the present invention, it is preferable that a right lower limit stopper portion be provided on the right support member to determine the lower limit position for up and down movement relative to the aircraft body at the right rear part of the cabin, and a left lower limit stopper portion be provided on the left support member to determine the lower limit position for up and down movement relative to the aircraft body at the left rear part of the cabin.

[0033] According to the present invention, a right (left) lower limit stopper portion is provided that determines the lower limit position for up and down movement of the right (left) rear part of the cabin relative to the aircraft body, thereby restricting excessive downward movement of the right (left) rear part of the cabin. According to the present invention, the lower limit stopper portion is provided on the support member, and the support member is also used as a member for attaching the lower limit stopper portion to the rear axle case, which is advantageous in terms of simplifying the structure. In this case, if the suspension mechanism is provided with an elastic body that determines the limit of the contraction operation of the aforementioned suspension mechanism, the elastic body and the lower limit stopper portion will work together to regulate excessive downward movement of the right (left) part of the cabin in a stable manner with little shock.

[0034] In the present invention, it is preferable that a right upper limit stopper portion be provided on the right support member and determine the upper limit position of up and down movement relative to the aircraft body in the right part of the rear of the cabin, and a left upper limit stopper portion be provided on the left support member and determine the upper limit position of up and down movement relative to the aircraft body in the left part of the rear of the cabin.

[0035] According to the present invention, a right (left) upper limit stopper portion is provided that determines the upper limit position of the up and down movement of the right (left) rear part of the cabin relative to the aircraft body, thereby restricting excessive upward movement of the right (left) rear part of the cabin. According to the present invention, the upper limit stopper portion is provided on the support member, and the support member is also used as a member for attaching the upper limit stopper portion to the rear axle case, which is advantageous in terms of simplifying the structure. In this case, if the aforementioned rebound spring is provided in the suspension mechanism, the rebound spring and the upper limit stopper portion work together to stably restrict excessive lifting of the right (left) part of the cabin with little shock.

[0036] In the present invention, it is preferable that a fixing member is provided that clamps the rear axle case with the support member, and that the support member and the fixing member are connected with the rear axle case clamped between them, thereby attaching the support member to the rear axle case, and that a regulating rod that regulates the left-right displacement of the link mechanism is connected between the link mechanism and the fixing member.

[0037] According to the present invention, when attaching a support member to a rear axle case, a fixing member is prepared, and the support member is attached to the rear axle case by connecting the support member and the fixing member with the rear axle case sandwiched between them.

[0038] In a work vehicle such as a tractor, when a link mechanism for supporting a work device is provided at the rear of the vehicle and extends rearward, a structure may be provided to prevent the link mechanism from displacing (swaying) left and right.

[0039] According to the present invention, the regulating rod is connected across the link mechanism and the fixed member, and the regulating rod regulates the left-right displacement (vibration) of the link mechanism.The fixed member is also used as a member for attaching the regulating rod to the rear axle case, which is advantageous in terms of simplifying the structure. [Brief explanation of the drawings]

[0040] [Figure 1] FIG. 2 is a left side view of the tractor. [Figure 2] FIG. 2 is a rear view of the rear of the tractor. [Figure 3] FIG. 2 is a plan view of the rear of the tractor. [Figure 4] FIG. 10 is a left side view of the vicinity of the left suspension mechanism and the left lateral rod. [Figure 5] FIG. 10 is a rear view of the vicinity of the left suspension mechanism and the left lateral rod. [Figure 6] FIG. 2 is a perspective view of the vicinity of the left suspension mechanism and the left lateral rod. [Figure 7] FIG. 2 is a vertical cross-sectional side view of the suspension mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0041] A tractor, which is an example of a work vehicle, is shown in Figures 1 to 7. In Figures 1 to 7, F indicates the forward direction, B indicates the backward direction, U indicates the upward direction, D indicates the downward direction, R indicates the rightward direction, and L indicates the leftward direction.

[0042] (Overall configuration of the tractor) As shown in Figure 1, a machine body 3 is supported by right and left front wheels 1 and right and left rear wheels 2 (corresponding to running gear). The machine body 3 has an engine 4, a clutch housing 5 connected to the rear of the engine 4, a transmission case 6 connected to the rear of the clutch housing 5, a front frame 7 connected to the front of the engine 4, etc.

[0043] The front wheels 1 are supported by the front frame 7. As shown in Figures 2 and 3, right and left rear axle cases 19 are connected to the rear of the transmission case 6 (machine body 3) and are provided so as to extend outward to the right and left from the rear of the transmission case 6 (machine body 3). The right and left rear wheels 2 are supported by the right and left rear axle cases 19.

[0044] As shown in Fig. 1, a bonnet 8 is provided at the front of the machine body 3, and the bonnet 8 covers the engine 4. A driver's section 9, in which an operator sits, is provided at the rear of the machine body 3, and the driver's section 9 is housed in a cabin 10. A driver's seat 11 and a steering wheel 12 for steering the front wheels 1 are provided in the driver's section 9.

[0045] (Configuration related to support of working equipment) 1, 2, and 3, a top link 13 and right and left lower links 14 are provided at the rear of the transmission case 6 (machine body 3) so as to be able to swing up and down and extend rearward, and the top link 13 and lower links 14 form a three-point linkage type link mechanism 18. A working implement such as a rotary tiller (not shown) or a plow (not shown) is connected to and supported by the link mechanism 18.

[0046] A PTO shaft 20 is provided at the rear of the transmission case 6 (machine body 3), and power from the PTO shaft 20 is transmitted via a transmission shaft (not shown) to a working device supported by a link mechanism 18. Flat right and left cover members 21 are connected to the rear of the transmission case 6 (machine body 3), and a cover member 22 is connected across the right and left cover members 21, so that the outer lateral sides and upper side of the PTO shaft 20 are covered by the cover members 21, 22.

[0047] Right and left lift arms 15 are provided on the upper rear portion of the transmission case 6 (aircraft body 3) so as to be able to swing up and down. Right and left lift cylinders 16 are connected between the lift arms 15 and a cover member 21, and the lift cylinders 16 are connected to the transmission case 6 (aircraft body 3) via the cover member 21.

[0048] A connecting rod 17 is connected between the lift arm 15 and the lower link 14, and when the lift arm 15 is raised and lowered by the lift cylinder 16, the lower link 14 (link mechanism 18) is raised and lowered, and the working device is raised and lowered.

[0049] (Outline of the cabin support structure) As shown in FIGS. 1, 2, and 3, the right and left front portions of the cabin 10 are supported on the clutch housing 5 (airframe 3) by right and left vibration-isolating rubbers 23. The right rear part of the cabin 10 is supported on the fuselage 3 by a right suspension mechanism 24, and the left rear part of the cabin 10 is supported on the fuselage 3 by a left suspension mechanism 24.

[0050] As a result, the rear part of the cabin 10 moves up and down relative to the aircraft body 3 by the suspension mechanism 24, with the lower part of the front part of the cabin 10 (the vibration-isolating rubber 23) as a fulcrum. Right and left lateral rods 25 are provided to allow the cabin 10 to move up and down relative to the fuselage 3 and to restrict the cabin 10 from moving left and right relative to the fuselage 3.

[0051] (Configuration of support member and fixing member) As shown in FIGS. 2 and 3, right and left support members 26 and right and left fixing members 27 are provided.

[0052] As shown in Figures 4, 5, and 6, the support member 26 is abutted against the upper surface of the rear axle case 19, and the fixing member 27 is abutted against the lower surface of the rear axle case 19, with the rear axle case 19 sandwiched between the support member 26 and the fixing member 27, and four bolts 28 are attached and tightened across the support member 26 and the fixing member 27.

[0053] With the rear axle case 19 sandwiched between the support member 26 and the fixing member 27, the support member 26 and the fixing member 27 are connected with bolts 28, whereby the right (left) support member 26 is attached to the right (left) rear axle case 19 and the right (left) fixing member 27 is attached to the right (left) rear axle case 19.

[0054] The support member 26 is provided with a flat plate-shaped base plate 26a, and four types of brackets 26b, 26c, 26d, and 26e are provided on the base plate 26a, and the right and left support members 26 are configured to be bilaterally symmetrical to each other.

[0055] As shown in Figure 2, the bracket 26c of the right (left) support member 26 is inserted into the wheel 2a of the right (left) rear wheel 2 so that the bracket 26c of the right (left) support member 26 overlaps with the wheel 2a of the right (left) rear wheel 2 when viewed from behind.

[0056] As shown in FIGS. 4, 5 and 6, right and left lower limit stopper portions 29 made of hard rubber are provided on the brackets 26d of the right and left support members 26. Right and left upper limit stoppers 30 are provided on the brackets 26e of the right and left support members 26. The upper limit stoppers 30 have a rod portion 30a and a flat plate-shaped receiving portion 30b attached to the upper portion of the rod portion 30a, and the lower portion of the rod portion 30a is attached to the brackets 26e of the support members 26.

[0057] The fixing member 27 is provided with a flat plate-shaped base plate 27a, and a bracket 27b is provided on a base plate 37a, and the right and left fixing members 27 are configured to be bilaterally symmetrical to each other. 1, 2, and 3, there are provided right and left regulating rods 31. The right (left) regulating rod 31 is connected across the right (left) lower link 14 (link mechanism 18) and the bracket 27b of the right (left) fixing member 27, and the regulating rod 31 regulates the left-right displacement (vibration) of the link mechanism 18.

[0058] (Suspension mechanism layout) 1 and 2, right and left frames 32 are connected to the right and left lower portions of the cabin 10 along the front-to-rear direction, and right and left frames 33 are connected between the right (left) portion of the rear of the cabin 10 and the rear portion of the frame 32, with the frames 32, 33 forming part of the cabin 10. Right and left rear wheel fenders 34 are attached to the frames 32, 33. Right and left brackets 35 are connected to the frame 33 and extend rearward.

[0059] 4, 5, and 6, the right suspension mechanism 24 is connected between the right bracket 35 and the bracket 26b of the right support member 26. The left suspension mechanism 24 is connected between the left bracket 35 and the bracket 26b of the left support member 26.

[0060] With the above configuration, as shown in Figure 2, the right suspension mechanism 24 is positioned to the right of the right lift arm 15 and the right lifting cylinder 16 when viewed from behind, and is connected between the right rear part of the cabin 10 and the right rear axle case 19, with the lower part of the right suspension mechanism 24 connected to the rear of the transmission case 6 (airframe 3) via the right rear axle case 19.

[0061] The left suspension mechanism 24 is positioned to the left and outward of the left lift arm 15 and the left lifting cylinder 16 when viewed from behind, and is connected across the left rear part of the cabin 10 and the left rear axle case 19, with the lower part of the left suspension mechanism 24 connected to the rear of the transmission case 6 (airframe 3) via the left rear axle case 19.

[0062] (Suspension mechanism configuration) As shown in FIG. 7, the right and left suspension mechanisms 24 are configured to include a suspension spring 38, a damper 39, an elastic body 40, a rebound spring 41, and the like.

[0063] The damper 39 is configured as a single cylinder and includes an outer cylinder 39a, a piston rod 39b, a piston 39c, and a free piston 39d. Inside the outer cylinder 39a, a piston 39c having a piston valve (orifice) (not shown) is attached to the lower part of the piston rod 39b, and the free piston 39d is disposed at the lower part of the outer cylinder 39a, thereby forming an oil chamber 39e and a gas chamber 39f.

[0064] A spring bearing 42 is connected to the upper part of the piston rod 39b of the damper 39, and a spring bearing 43 is connected to the outer cylinder 39a of the damper 39. The suspension spring 38 is attached across the spring bearings 42 and 43, and a cover 44 that covers the suspension spring 38 is attached to the spring bearing 42.

[0065] The elastic body 40 is cylindrical (ring-shaped) and made of synthetic rubber, urethane, etc., and is positioned between the upper end of the outer tube 39a of the damper 39 and the spring bearing 42, and is attached to the piston rod 39b of the damper 39. A rebound spring 41 is attached inside the outer cylinder 39a of the damper 39, spanning the upper end of the outer cylinder 39a of the damper 39 and the piston 39c.

[0066] In the suspension mechanism 24 configured as described above, the upper end of the piston rod 39b of the damper 39 is attached to the bracket 35 (see Figures 4, 5, and 6), and the lower end of the outer cylinder 39a of the damper 39 is attached to the bracket 26b of the support member 26.

[0067] (Lateral rod configuration) 4, 5, and 6, right and left support plates 36 are provided, each made of a plate bent in a crank shape, and the support plates 36 are connected to the rear of the frame 32. Right and left brackets 37 are provided, and the brackets 37 are connected to the rear of the frame 32.

[0068] There are provided right and left lateral rods 25. The right lateral rod 25 is connected across the right bracket 37 and the bracket 26c of the right support member 26, and is disposed between the brackets 26b and 26d of the right support member 26.

[0069] The left lateral rod 25 is connected across the left bracket 37 and the bracket 26c of the left support member 26, and is disposed between the brackets 26b and 26d of the left support member 26.

[0070] As shown in Figures 2 and 5, when no operator is riding in the driver's section 9, the right suspension mechanism 24 is set so that the right lateral rod 25 extends diagonally downward from the right bracket 37 (the right rear part of the cabin 10) to the right outer lateral side, and is connected to the bracket 26c of the right support member 26.

[0071] When no operator is on board the driver's section 9, the left suspension mechanism 24 is set so that the left lateral rod 25 extends diagonally downward from the left bracket 37 (the left rear part of the cabin 10) to the left outer side, and is connected to the bracket 26c of the left support member 26.

[0072] When the operator gets on the driver's section 9, the suspension mechanism 24 contracts slightly due to the operator's weight, and the right and left lateral rods 25 move from the positions shown in FIGS. 2 and 5 to a position close to horizontal.

[0073] In the above-described state, when the right (left) rear part of the cabin 10 moves up and down (when the right (left) suspension mechanism 24 expands and contracts), the right (left) lateral rod 25 swings up and down from a nearly horizontal position, with the bracket 26c of the right (left) support member 26 as a fulcrum. As a result, the right (left) lateral rod 25 allows the cabin 10 to move up and down relative to the fuselage 3, and restricts the cabin 10 from moving left and right relative to the fuselage 3.

[0074] 2, the right lateral rod 25 is disposed laterally outward of the right suspension mechanism 24 in rear view and is connected to the right part of the cabin 10. The left lateral rod 25 is disposed laterally outward of the left suspension mechanism 24 in rear view and is connected to the left part of the cabin 10.

[0075] The right lateral rod 25 is connected between the right rear part of the cabin 10 and the bracket 26c of the right support member 26, and the right part of the right lateral rod 25 is connected to the right rear axle case 19 via the right support member 26.

[0076] The left lateral rod 25 is connected between the left rear portion of the cabin 10 and the bracket 26c of the left support member 26, and the left portion of the left lateral rod 25 is connected to the left rear axle case 19 via the left support member 26.

[0077] The right portion of the right lateral rod 25 (bracket 26c of the right support member 26) is inserted into the wheel 2a of the right rear wheel 2 so that the right portion of the right lateral rod 25 (bracket 26c of the right support member 26) overlaps with the wheel 2a of the right rear wheel 2 when viewed from behind.

[0078] The left portion of the left lateral rod 25 (bracket 26c of the left support member 26) is inserted into the wheel 2a of the left rear wheel 2 so that the left portion of the left lateral rod 25 (bracket 26c of the left support member 26) overlaps with the wheel 2a of the left rear wheel 2 when viewed from behind.

[0079] 1 and 4, the right lateral rod 25 is disposed forward of the right suspension mechanism 24 in a side view, and is disposed between the cabin 10 and the right suspension mechanism 24. The left lateral rod 25 is disposed forward of the left suspension mechanism 24 in a side view, and is disposed between the cabin 10 and the left suspension mechanism 24.

[0080] (Configuration of lower limit stopper portion and upper limit stopper portion) 4, 5, and 6, the right lower limit stopper portion 29 provided on the bracket 26d of the right support member 26 is located below the right receiving plate 36. The left lower limit stopper portion 29 provided on the bracket 26d of the left support member 26 is located below the left receiving plate 36.

[0081] Openings 36a are provided in the right and left receiving plates 36, and the rod portions 30a of the right and left upper limit stopper portions 30 fit into the openings 36a of the receiving plates 36. The receiving portions 30b of the upper limit stopper portions 30 are configured to have a larger diameter than the openings 36a of the receiving plates 36.

[0082] With the above configuration, the position of the right lower limit stopper portion 29 is the lower limit position for up and down movement relative to the fuselage 3 at the right part of the rear of the cabin 10. When the right rear part of the cabin 10 descends (when the right suspension mechanism 24 contracts), shortly before the right receiving plate 36 hits the right lower limit stopper portion 29, in the right suspension mechanism 24, the upper end of the outer tube 39a of the damper 39 hits the right elastic body 40, as shown in Figure 7, and the right elastic body 40 is compressed.As the right receiving plate 36 hits the right lower limit stopper portion 29, the right elastic body 40 and the right lower limit stopper portion 29 restrict the downward movement of the right rear part of the cabin 10.

[0083] The position of the left lower limit stopper portion 29 is the lower limit position for up and down movement relative to the fuselage 3 at the left rear of the cabin 10. When the left rear part of the cabin 10 descends (when the left suspension mechanism 24 contracts), shortly before the left receiving plate 36 hits the left lower limit stopper portion 29, as shown in Figure 7, the upper end of the outer tube 39a of the damper 39 in the left suspension mechanism 24 hits the left elastic body 40, compressing the left elastic body 40.As a result of the left receiving plate 36 hitting the left lower limit stopper portion 29, the left elastic body 40 and the left lower limit stopper portion 29 restrict the downward movement of the left rear part of the cabin 10.

[0084] When the right (left) elastic body 40 is compressed, when the elastic body 40 reaches its compression limit (a state in which the elastic body 40 is not compressed), the right (left) receiving plate 36 is set to come into contact with the right (left) lower limit stopper portion 29. As a result, shock is absorbed as the right (left) elastic body 40 is compressed, and when the right (left) elastic body 40 reaches its compression limit, the lowering operation of the right (left) part of the rear of the cabin 10 is restricted, and the shock when the right (left) receiving plate 36 comes into contact with the right (left) lower limit stopper portion 29 is suppressed.

[0085] When the right (left) suspension mechanism 24 is contracted, as shown in Figure 7, the piston 39c of the damper 39 in the right (left) suspension mechanism 24 moves in a direction (downward) away from the rebound spring 41. As a result, the right (left) rebound spring 41 is not compressed, and the right (left) rebound spring 41 does not provide resistance to the contraction of the right (left) suspension mechanism 24.

[0086] The position of the receiving portion 30b of the right upper limit stopper portion 30 is the upper limit position for up and down movement of the right rear part of the cabin 10 relative to the fuselage 3. When the right rear part of the cabin 10 rises, the right receiving plate 36 hits the receiving portion 30b of the right upper limit stopper portion 30, thereby restricting the upward movement of the right rear part of the cabin 10.

[0087] The position of the receiving portion 30b of the left upper limit stopper portion 30 is the upper limit position for up and down movement of the left rear part of the cabin 10 relative to the fuselage 3. When the left rear part of the cabin 10 rises, the left receiving plate 36 hits the receiving portion 30b of the left upper limit stopper portion 30, thereby restricting the upward movement of the left rear part of the cabin 10.

[0088] When the right (left) suspension mechanism 24 is extended, as shown in Figure 7, the piston 39c of the damper 39 in the right (left) suspension mechanism 24 moves in a direction (upward) approaching the rebound spring 41. As a result, the rebound spring 41 is compressed by the piston 39c of the damper 39, and the right (left) rebound spring 41 applies resistance to the extension operation of the right (left) suspension mechanism 24.

[0089] When the right (left) suspension mechanism 24 is extended, the right (left) rebound spring 41 is compressed and shock is absorbed, thereby suppressing the shock when the right (left) receiving plate 36 hits the receiving portion 30b of the right (left) upper limit stopper portion 30.

[0090] (First Alternative Embodiment of the Invention) The right and left rear parts of the cabin 10 may be supported on the rear of the transmission case 6 (airframe 3) by right and left vibration-damping rubbers 23, and the right and left front parts of the cabin 10 may be supported on the clutch housing 5 (airframe 3) by right and left suspension mechanisms 24.

[0091] (Second Alternative Embodiment of the Invention) Instead of the rear wheels 2, a crawler traveling device (not shown) may be configured to be supported on the rear axle case 19 as the traveling device.

[0092] (Third Alternative Embodiment of the Invention) In FIG. 7, the elastic body 40 may be configured to be connected across the upper end of the outer cylinder 39a of the damper 39 and the spring bearing 42 without leaving any gap between the elastic body 40 and the upper end of the outer cylinder 39a of the damper 39. The elastic body 40 may be made of not only synthetic rubber or urethane but also a short metal coil spring (not shown). [Industrial Applicability]

[0093] The present invention can be applied not only to tractors but also to agricultural work vehicles such as combine harvesters equipped with cabins, and construction work vehicles such as backhoes and wheel loaders equipped with cabins. [Explanation of symbols]

[0094] 2 Rear wheels (running gear) 3 aircraft 9 Driving Department 10 Cabins 15 Lift arm 16 Lifting cylinder 18 Link mechanism 19 Rear axle case 24 Suspension mechanism 25 Lateral Rod 26 Support member 27 Fixing member 29 Lower limit stopper 30 Upper limit stopper 31 Regulating rod 40 Elastic Body 41 Rebound spring

Claims

1. a driver's section in which an operator rides; a cabin that houses the driver's section; right and left suspension mechanisms that support the right and left portions of the cabin on an airframe; right and left lateral rods that allow the cabin to move up and down relative to the fuselage and restrict the cabin to move left and right relative to the fuselage, the right lateral rod is disposed laterally outward on the right side of the right suspension mechanism and connected to a right portion of the cabin; the left lateral rod is disposed laterally outward of the left suspension mechanism and connected to a left portion of the cabin; a link mechanism that is provided at the rear of the machine body so as to be able to swing up and down, extends rearward, and supports a working device; a lift arm provided at the rear of the machine body so as to be able to swing up and down and which operates to raise and lower the link mechanism; a lifting cylinder connected between the machine body and the lift arm and configured to lift and lower the lift arm; the right suspension mechanism is disposed laterally outward on the right side of the lift arm and the lift cylinder, and supports a right portion of a rear portion of the cabin; The left suspension mechanism is disposed laterally outward to the left of the lift arm and the lifting cylinder, and supports the left rear portion of the cabin.

2. When no operator is on board the driver's section, the right lateral rod is in a position where it extends diagonally downward from the right part of the cabin to the right lateral outer side, When no operator is on board the driver's section, the left lateral rod is in a position where it extends diagonally downward from the left part of the cabin to the left lateral outside, 2. The work vehicle according to claim 1, wherein the right and left suspension mechanisms are set so that the right and left lateral rods are in a nearly horizontal position when an operator is seated in the driver's section.

3. a right elastic body provided in the right suspension mechanism and determining a limit of the contraction operation of the right suspension mechanism; 2. A work vehicle according to claim 1, further comprising a left elastic body provided in said left suspension mechanism for determining a limit of contraction of said left suspension mechanism.

4. a right rebound spring provided in the right suspension mechanism, the right rebound spring providing resistance to an extension operation of the right suspension mechanism and not providing resistance to a contraction operation of the right suspension mechanism; 2. The work vehicle according to claim 1, further comprising a left rebound spring provided in the left suspension mechanism, the left rebound spring providing resistance to the extension operation of the left suspension mechanism but not providing resistance to the contraction operation of the left suspension mechanism.

5. Right and left rear axle cases are provided extending outward from the rear of the vehicle body to the right and left sides, and support right and left running gears; the right lateral rod is connected across the right rear portion of the cabin and the right rear axle case, 2. The work vehicle according to claim 1, wherein the left lateral rod is connected across a left portion of the rear of the cabin and the left rear axle case.

6. The right portion of the right lateral rod enters the right traveling device so that the right portion of the right lateral rod and the right traveling device overlap in rear view, 6. The work vehicle according to claim 5, wherein a left portion of the left lateral rod is inserted into the left traveling device so that the left portion of the left lateral rod and the left traveling device overlap in a rear view.

7. the right lateral rod is disposed between the cabin and the right suspension mechanism in a side view, 7. The work vehicle according to claim 6, wherein the left lateral rod is disposed between the cabin and the left suspension mechanism in a side view.

8. the right suspension mechanism is connected across a right portion of the rear of the cabin and the right rear axle case, 8. The work vehicle according to claim 7, wherein the left suspension mechanism is connected across a left portion of the rear of the cabin and the left rear axle case.

9. right and left support members attached to the right and left rear axle cases; the right suspension mechanism and the right lateral rod are connected to the right support member; 9. The work vehicle according to claim 8, wherein the left suspension mechanism and the left lateral rod are connected to the left support member.

10. a right lower limit stopper portion provided on the right support member and determining a lower limit position of vertical movement relative to the aircraft body at the right part of the rear of the cabin; 10. The work vehicle according to claim 9, further comprising a left lower limit stopper portion provided on the left support member for determining a lower limit position for vertical movement relative to the vehicle body at the left rear portion of the cabin.

11. a right upper limit stopper portion provided on the right support member and determining an upper limit position of vertical movement relative to the aircraft body at the right part of the rear of the cabin; 10. The work vehicle according to claim 9, further comprising a left upper limit stopper portion provided on the left support member for determining an upper limit position of vertical movement relative to the vehicle body at the left rear portion of the cabin.

12. a fixing member that sandwiches the rear axle case between the support member and the fixing member; The support member and the fixing member are connected together in a state in which the rear axle case is sandwiched between the support member and the fixing member, thereby attaching the support member to the rear axle case, 10. The work vehicle according to claim 9, wherein a restricting rod that restricts left-right displacement of the link mechanism is connected between the link mechanism and the fixed member.

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