Work vehicle

Abstract

To provide a work vehicle in which a cabin is supported by a machine body via a suspension mechanism, the cabin being configured so as to be stopped at a lower limit position (or an upper limit position).SOLUTION: A work vehicle includes a stopper member 30 attached to one of a machine body and a cabin, and a receiving part 36 attached to the other of the machine body and the cabin. The stopper member 30 has a first elastic body 31 attached to one of the machine body and the cabin, and a second elastic body 32 connected to the first elastic body 31 to touch the receiving part 36. The second elastic body 32 having a degree of hardness lower than that of the first elastic body 31, is formed into a shape in such a manner that the area of a stop part 32a of the second elastic body 32 that touches the receiving part 36 becomes smaller than the area of a connection end 32b connected to the first elastic body 31 of the second elastic body 32.SELECTED DRAWING: Figure 6

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, the cabin is configured to be supported on the vehicle body via a suspension mechanism, as disclosed in Patent Document 1. This reduces vibrations in the driver's section where the worker sits, even if the vehicle body vibrates when traveling on rough terrain. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-268664 Summary of the Invention [Problem to be solved by the invention]

[0004] When the cabin is supported on the aircraft body via a suspension mechanism and configured to move up and down relative to the aircraft body, it is necessary to provide a stopper structure that determines the lower limit position of the cabin relative to the aircraft body, or a stopper structure that determines the upper limit position of the cabin relative to the aircraft body.

[0005] The present invention aims to configure a work vehicle in which a cabin is supported on a vehicle body via a suspension mechanism so that the cabin can be stopped at the lowest position (highest position) with minimal shock. [Means for solving the problem]

[0006] The work vehicle of the present invention comprises a machine body supported by a traveling device, a driver's section in which a worker rides, a cabin that houses the driver's section, a suspension mechanism that supports the cabin on the machine body, a stopper member attached to one of the machine body and the cabin, and a receiving section attached to the other of the machine body and the cabin, and expansion and contraction of the suspension mechanism causes the stopper member to come into contact with the receiving section, and the stopper member is compressed, thereby determining at least one of a lower limit position of the cabin relative to the machine body and an upper limit position of the cabin relative to the machine body, the stopper member having a first elastic body attached to one of the machine body and the cabin, and a second elastic body connected to the first elastic body and coming into contact with the receiving section, the second elastic body having a hardness lower than that of the first elastic body, and formed in a shape such that the area of ​​the contacting section of the second elastic body that comes into contact with the receiving section is smaller than the area of ​​the connecting end of the second elastic body connected to the first elastic body. the cross-sectional area of ​​the second elastic body in a plane perpendicular to the direction along the extension and contraction direction of the suspension mechanism becomes smaller as the portion of the second elastic body approaches the contact portion, the outer periphery of the second elastic body is circular when viewed in the direction along the extension and contraction direction of the suspension mechanism, and the radius of the outer periphery of the second elastic body becomes smaller as the portion of the second elastic body approaches the contact portion, and the outer periphery of the first elastic body is circular when viewed in the direction along the extension and contraction direction of the suspension mechanism, and the radius of the outer periphery of the first elastic body is the same as the radius of the outer periphery of the connecting end of the second elastic body. .

[0007] According to the present invention, when the cabin reaches near the lower limit position (upper limit position) due to the extension and contraction of the suspension mechanism, the second elastic body and the receiving portion of the stopper member come into contact, and the first elastic body and the second elastic body are compressed as described below, causing the cabin to stop at the lower limit position (upper limit position).

[0008] According to the present invention, when the second elastic body comes into contact with the receiving portion, the second elastic body is mainly compressed because the hardness of the second elastic body is lower than the hardness of the first elastic body, and the movement of the cabin is mainly absorbed by the second elastic body. According to the present invention, the area of ​​the contact portion of the second elastic body that comes into contact with the receiving portion is smaller than the area of ​​the connection end of the second elastic body connected to the first elastic body, so that the deceleration in the cabin's movement speed is small at the initial point when the contact portion of the second elastic body and the receiving portion begin to come into contact.

[0009] When the second elastic body is sufficiently compressed, the first elastic body is then mainly compressed. The movement of the cabin is mainly absorbed by the first elastic body, and because the hardness of the first elastic body is higher than that of the second elastic body, the movement speed of the cabin is relatively greatly decelerated, and the cabin stops at the lower limit position (upper limit position).

[0010] According to the present invention, in the initial stage when the cabin reaches near the lower limit position (upper limit position), the hardness of the second elastic body is lower than that of the first elastic body, and the area of ​​the contact portion of the second elastic body is relatively small, so that the movement speed of the cabin is slowed down relatively slightly mainly by the second elastic body, and the movement of the cabin is absorbed with little shock. Next, the movement speed of the cabin is slowed down relatively greatly mainly by the first elastic body, and the cabin stops at the lower limit position (upper limit position). As described above, the stopper member (first elastic body and second elastic body) makes it possible to stop the cabin at the lower limit position (upper limit position) with less shock, thereby improving the ride comfort of the work vehicle.

[0011] In the present invention, it is preferable that the length of the first elastic body in the direction along the extension and contraction direction of the suspension mechanism is longer than the length of the second elastic body in the direction along the extension and contraction direction of the suspension mechanism.

[0012] According to the present invention, the length of the first elastic body in the direction along the extension and contraction direction of the suspension mechanism is relatively long, which is advantageous in that the movement of the cabin is sufficiently absorbed by the first elastic body, and the ride comfort of the work vehicle can be improved while also improving the function of stopping the cabin at the lower limit position (upper limit position).

[0013] In the present invention, it is preferable that the contact portion of the second elastic body is formed on a plane parallel to a plane perpendicular to a direction along the extension and contraction direction of the suspension mechanism.

[0014] According to the present invention, when the cabin approaches the lower limit position (upper limit position) and the contact portion of the second elastic body comes into contact with the receiving portion, the contact portion of the second elastic body is more likely to contact the receiving portion evenly with less bias, making it easier for the second elastic body to fully perform its function, which is advantageous in that the second elastic body can slow down the cabin's movement speed relatively slightly while absorbing the cabin's movement with less shock.

[0015] In the present invention, it is preferable that the cross-sectional area of ​​the second elastic body in a plane perpendicular to the direction along the extension / contraction direction of the suspension mechanism becomes smaller toward the contact portion of the second elastic body.

[0016] According to the present invention, after the contact portion of the second elastic body begins to come into contact with the receiving portion, as the contact between the second elastic body and the receiving portion progresses, the cross-sectional area of ​​the second elastic body at the position of the receiving portion gradually increases, and the deceleration of the cabin movement speed gradually increases, which is advantageous in that the second elastic body decelerates the cabin movement speed relatively slightly while absorbing the cabin movement with little shock.

[0017] In the present invention, it is preferable that when viewed from a direction along the extension / contraction direction of the suspension mechanism, the outer periphery of the second elastic body is circular, and the radius of the outer periphery of the second elastic body becomes smaller as the portion closer to the contact portion of the second elastic body becomes smaller.

[0018] According to the present invention, in the stopper member, the outer periphery of the second elastic body is circular when viewed from a direction along the extension / contraction direction of the suspension mechanism, which makes it easier to produce the second elastic body and is advantageous in terms of reducing production costs.

[0019] According to the present invention, the radius of the outer circumferential portion of the second elastic body becomes smaller as the portion of the second elastic body approaches the contact portion, and the second elastic body has a tapered shape. As a result, when the cabin approaches the lower limit position (upper limit position) and the contact portion of the second elastic body comes into contact with the receiving portion, the contact portion of the second elastic body is more likely to contact the receiving portion evenly with less bias, making it easier for the second elastic body to fully perform its function, which is advantageous in that the second elastic body can slow down the cabin's movement speed relatively slightly while absorbing the cabin's movement with less shock.

[0020] In the present invention, it is preferable that when viewed from a direction along the extension / contraction direction of the suspension mechanism, the outer periphery of the first elastic body is circular, and that the radius of the outer periphery of the first elastic body is the same as the radius of the outer periphery of the connecting end of the second elastic body.

[0021] According to the present invention, in the stopper member, the outer periphery of the first elastic body is circular when viewed from a direction along the extension / contraction direction of the suspension mechanism, which makes it easier to produce the first elastic body and is advantageous in terms of reducing production costs.

[0022] According to the present invention, the radius of the outer periphery of the first elastic body is the same as the radius of the outer periphery of the connecting end of the second elastic body, which is relatively large. The radius of the outer periphery of the first elastic body is the same at each part of the first elastic body in the direction along the extension and contraction direction of the suspension mechanism.

[0023] As a result, when the second elastic body is sufficiently compressed and then the first elastic body is compressed, the movement of the cabin is sufficiently absorbed by the first elastic body, so that after the second elastic body is sufficiently compressed, the cabin stops at the lower limit position (upper limit position) with little delay, thereby improving the ride comfort of the work vehicle while enhancing the function of stopping the cabin at the lower limit position (upper limit position).

[0024] In the present invention, it is preferable that an opening is formed in the second elastic body, penetrating from the contact portion of the second elastic body to the connection end portion of the second elastic body.

[0025] According to the present invention, the second elastic body is formed in a cylindrical shape and the contact portion of the second elastic body is formed in a ring shape, which is advantageous in that when the cabin reaches near the lower limit position (upper limit position) and the contact portion of the second elastic body comes into contact with the receiving portion, the contact portion of the second elastic body comes into contact with the receiving portion evenly with little bias, and the second elastic body slows down the movement speed of the cabin relatively slightly, while absorbing the movement of the cabin with little shock.

[0026] In the present invention, it is preferable that a recess having a bottom is formed in the first elastic body from the connection end of the first elastic body connected to the connection end of the second elastic body toward the mounting end of the first elastic body attached to one of the airframe and the cabin.

[0027] According to the present invention, a recess is formed in the connection end of the first elastic body connected to the connection end of the second elastic body, and the opening of the second elastic body is connected to the recess of the first elastic body. The difference between the cross-sectional area at the connection end of the second elastic body and the cross-sectional area at the connection end of the first elastic body is small, and the change in cross-sectional area from the connection end of the second elastic body to the connection end of the first elastic body is small.

[0028] This allows the cabin movement to be smoothly absorbed when the second elastic body is sufficiently compressed and transitions to compression of the first elastic body when the cabin approaches the lower limit position (upper limit position), which is advantageous in that it improves the ride comfort of the work vehicle while also enhancing the function of stopping the cabin at the lower limit position (upper limit position).

[0029] In the present invention, it is preferable that a bolt is attached between the bottom of the recess of the first elastic body and one of the airframe and the cabin, and the first elastic body is attached to one of the airframe and the cabin.

[0030] According to the present invention, when a recess is formed at the connection end of the first elastic body, the recess in the first elastic body can be effectively utilized to attach the first elastic body to either the aircraft body or the cabin, thereby simplifying the attachment structure of the stopper member.

[0031] According to the present invention, when the cabin reaches the lower limit position (upper limit position), the second elastic body is sufficiently compressed to compress the first elastic body, and even if the first elastic body is sufficiently compressed, if the cabin does not stop at the lower limit position (upper limit position), it is expected that the cabin will stop as the receiving portion and the bolt come into contact.

[0032] In the present invention, it is preferable that the first elastic body and the second elastic body are made of urethane.

[0033] According to the present invention, the first elastic body and the second elastic body can be simply made of urethane, which is advantageous in terms of reducing production costs.

[0034] In the present invention, it is preferable that the second elastic body is urethane foam.

[0035] According to the present invention, since the second elastic body is urethane foam, it is easy to set the hardness of the second elastic body lower than the hardness of the first elastic body. [Brief explanation of the drawings]

[0036] [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. 2 is a left side view of the vicinity of the left suspension mechanism. [Figure 5] FIG. 2 is a front view of the left suspension mechanism and its vicinity. [Figure 6] FIG. 10 is a vertical sectional rear view of the vicinity of the upper limit stopper member and the lower limit stopper member in the left suspension mechanism. [Figure 7] 4A and 4B are a plan view and a cross-sectional view of a lower limit stopper member. [Figure 8] FIG. 10 is a cross-sectional view of a lower limit stopper member in the first alternative embodiment of the invention. [Figure 9] FIG. 10 is a cross-sectional view of a lower limit stopper member in a second alternative embodiment of the invention. [Figure 10] FIG. 10 is a cross-sectional view of a lower limit stopper member in a third alternative embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] A tractor, which is an example of a work vehicle, is shown in Figures 1 to 10. In Figures 1 to 10, 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.

[0038] (Overall configuration of the tractor) 1, a machine body 3 is supported by right and left front wheels 1 (corresponding to the running gear) and right and left rear wheels 2 (corresponding to the 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.

[0039] 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 laterally outward to the right and left from the rear of the transmission case 6 (machine body 3).

[0040] 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.

[0041] (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.

[0042] 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.

[0043] 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.

[0044] A linking rod 17 is connected between the lift arm 15 and the lower link 14. 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.

[0045] (Outline of the cabin support structure) 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 portion of the cabin 10 is supported on the airframe 3 by a right suspension mechanism 24, and the left rear portion of the cabin 10 is supported on the airframe 3 by a left suspension mechanism 24.

[0046] 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 as described below 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.

[0047] An upper limit stopper member 29 is provided as described below, and the upper limit position of the cabin 10 relative to the fuselage 3 is determined by the upper limit stopper member 29. A lower limit stopper member 30 is provided as described below, and the lower limit position of the cabin 10 relative to the fuselage 3 is determined by the lower limit stopper member 30.

[0048] The above configuration provides the machine body 3 supported by the front wheels 1 (traveling device) and the rear wheels 2 (traveling device), the driver's section 9 in which the operator sits, and the cabin 10 that houses the driver's section 9. A suspension mechanism 24 that supports the cabin 10 on the machine body 3 is provided.

[0049] (Configuration of support members that support the suspension mechanism, lateral rod, upper limit stopper member, and lower limit stopper member) As shown in Figures 1, 2, and 3, there are provided right and left support members 26. As shown in Figures 4 and 5, the support member 26 has a main body portion 26a, a base portion 26b, a top plate portion 26c, mounting portions 26d and 26e, a reinforcing portion 26f, etc., and the right and left support members 26 are configured to have bilaterally symmetrical shapes.

[0050] In the support member 26, a flat base plate portion 26b is connected to the lower part of the main body portion 26a, and a flat top plate portion 26c is connected to the upper part of the main body portion 26a. The top plate portion 26c extends rearward from the main body portion 26a, and a reinforcing portion 26f is connected across the main body portion 26a, the base plate portion 26b, and the top plate portion 26c. An attachment portion 26d is connected upward to the rear part of the top plate portion 26c, and an attachment portion 26e is connected laterally outward to the main body portion 26a.

[0051] As shown in Figures 1 and 2, there are provided right and left fixing members 27. As shown in Figures 2 and 4, the fixing member 27 has a flat plate-shaped base portion 27a and an attachment portion 27b connected to the base portion 27a, and the right and left fixing members 27 are configured to be bilaterally symmetrical to each other.

[0052] A base plate portion 26b of the support member 26 is abutted against the upper surface of the rear axle case 19, and a base plate portion 27a of the fixing member 27 is abutted against the lower surface of the rear axle case 19. Four bolts 28 are attached and tightened across the base plate portion 26b of the support member 26 and the base plate portion 27a of the fixing member 27, thereby attaching the support member 26 and the fixing member 27 to the rear axle case 19.

[0053] 1, 2, and 3, there are provided right and left regulating rods 38. The right (left) regulating rod 38 is connected across the right (left) lower link 14 (link mechanism 18) and the mounting portion 27b of the right (left) fixed member 27, and the regulating rod 38 regulates the left-right displacement (vibration) of the link mechanism 18.

[0054] (Suspension mechanism configuration) 1, 2, and 3, right and left frames 39 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 39, with the frames 39, 33 forming part of the cabin 10. Right and left rear wheel fenders 34 are attached to the frames 39, 33. Right and left mounting portions 35 are connected to the frame 33 and extend rearward.

[0055] 1 to 4, the suspension mechanism 24 is configured to include a suspension spring 24a and a damper 24b. The right suspension mechanism 24 is connected between the right mounting portion 35 and the mounting portion 26d of the right support member 26. The left suspension mechanism 24 is connected between the left mounting portion 35 and the mounting portion 26d of the left support member 26.

[0056] 2, the right suspension mechanism 24 is disposed laterally outward to the right of the right lift arm 15 and the right lift cylinder 16 in rear view, and is connected across the right rear part of the cabin 10 and the right rear axle case 19. A lower part of the right suspension mechanism 24 is connected to the rear of the transmission case 6 (airframe 3) via the right rear axle case 19.

[0057] The left suspension mechanism 24 is disposed laterally outward to the left of the left lift arm 15 and the left lift cylinder 16 in rear view, and is connected across the left rear part of the cabin 10 and the left rear axle case 19. A lower part of the left suspension mechanism 24 is connected to the rear of the transmission case 6 (airframe 3) via the left rear axle case 19.

[0058] (Lateral rod configuration) As shown in FIGS. 4 and 5, right and left mounting portions 37 are provided, and the mounting portions 37 are connected to the rear portion of the frame 39 and extend downward from the frame 39.

[0059] There are provided right and left lateral rods 25. The right lateral rod 25 is connected across the right mounting portion 37 and the mounting portion 26e of the right support member 26, and is disposed forward of the main body portion 26a of the right support member 26 and the right suspension mechanism 24.

[0060] The left lateral rod 25 is connected across the left mounting portion 37 and the mounting portion 26e of the left support member 26, and is positioned forward of the main body portion 26a of the left support member 26 and the left suspension mechanism 24.

[0061] When no operator is riding on the driver's unit 9, the right and left suspension mechanisms 24 are set so that the right and left lateral rods 25 extend diagonally downward from the mounting parts 37 to the right and left outer sides. When an operator rides on the driver's unit 9, the suspension mechanisms 24 contract slightly due to the operator's weight, and the right and left lateral rods 25 assume a nearly horizontal position.

[0062] In the above-described state, when the right (left) part of the rear 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 mounting part 26e 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.

[0063] (Configuration of upper limit stopper member) As shown in Figures 2 and 3, there are provided right and left receiving portions 36. As shown in Figures 4, 5, and 6, the receiving portion 36 has a first portion 36a formed by bending a plate material into a channel shape, and a flat second portion 36b connected to the lower portion of the first portion 36a.

[0064] The receiving portion 36 is connected to the rear of the frame 39, extends laterally outward from the frame 39, and is attached to the cabin 10 (frame 39). A flat cover 40 is connected to the rear of the first portion 36a of the receiving portion 36.

[0065] 2 and 3, the right upper limit stopper member 29 is provided on the right support member 26, and the left upper limit stopper member 29 is provided on the left support member 26. As shown in FIGS. 4, 5, and 6, the upper limit stopper member 29 has a rod portion 29a and a contact portion 29b.

[0066] The rod portion 29a of the upper limit stop member 29 is connected to the top plate portion 26c of the support member 26. A circular opening 36c is formed in the first portion 36a of the receiving portion 36. The rod portion 29a of the upper limit stop member 29 extends upward from the top plate portion 26c of the support member 26, passes laterally outward of the second portion 36b of the receiving portion 36, and passes through the opening 36c of the receiving portion 36. The contact portion 29b of the upper limit stop member 29 is formed in a semicircular shape, has a diameter larger than the opening 36c of the receiving portion 36, and is connected to the upper end of the rod portion 29a.

[0067] The position of the contact portion 29b of the right (left) upper limit stopper member 29 is the upper limit position of the up and down movement of the right (left) part of the rear of the cabin 10 relative to the fuselage 3. When the right (left) suspension mechanism 24 is extended and the right (left) rear part of the cabin 10 rises relative to the fuselage 3, the contact portion 29b of the right (left) upper limit stopper member 29 comes into contact with the first part 36a of the right (left) receiving portion 36, causing the right (left) rear part of the cabin 10 to stop at the upper limit position.

[0068] (Configuration of lower limit stopper member) - 1 As shown in FIGS. 1, 2 and 3, a right lower limit stopper member 30 (corresponding to a stopper member) and a left lower limit stopper member 30 (corresponding to a stopper member) are provided.

[0069] The lower limit stop member 30 is attached to a portion of the top plate portion 26c of the support member 26 that is closer to the frame 39 (cabin 10) than the upper limit stop member 29, and is located below the second portion 36b of the receiving portion 36. The lower limit stop member 30 is attached to the fuselage 3 via the support member 26 and the rear axle case 19.

[0070] 4 and 5, the lower limit stopper member 30 is provided between the lateral rod 25 (mounting portion 37) and the suspension mechanism 24 (mounting portion 26d of the support member 26) in a side view. A cover 40 is located behind the lower limit stopper member 30, and protects the rear portion of the lower limit stopper member 30.

[0071] With the above configuration, the lower limit stopper member 30 (stopper member) attached to one of the machine body 3 and the cabin 10, and the receiving portion 36 attached to the other of the machine body 3 and the cabin 10 are provided.

[0072] (Configuration of lower limit stopper member)-2 7, the lower limit stopper member 30 has a first elastic body 31 and a second elastic body 32. The first elastic body 31 is integrally formed from urethane, and the second elastic body 32 is integrally formed from urethane (urethane foam). The first elastic body 31 and the second elastic body 32 are bonded together to form the lower limit stopper member 30.

[0073] In the lower limit stopper member 30, the hardness of the second elastic body 32 is set lower than the hardness of the first elastic body 31 due to the difference in the degree of foaming of the urethane, and the second elastic body 32 is softer than the first elastic body 31. In this case, the hardness of the first elastic body 31 is preferably 90 to 100 (Durometer A, instantaneous), and the hardness of the second elastic body 32 is preferably 68 to 88 (Asker C, instantaneous).

[0074] (Configuration of lower limit stopper member) - 3 7, in the first elastic body 31 of the lower limit stopper member 30, the outer periphery of the first elastic body 31 is circular when viewed in the up-down direction A1 (corresponding to the direction along the extension and contraction direction of the suspension mechanism 24). The radius B11 of the outer periphery of the first elastic body 31 is the same throughout the entire portion of the first elastic body 31 in the up-down direction A1.

[0075] The upper end of the first elastic body 31 is the connecting end 31a, and the lower end of the first elastic body 31 is the mounting end 31b. The connecting end 31a and the mounting end 31b of the first elastic body 31 are formed on a plane parallel to a plane C1 perpendicular to the up-down direction A1. A recess 31c having a bottom is formed in the first elastic body 31 from the connecting end 31a toward the mounting end 31b of the first elastic body 31. An opening 31d is opened in the first elastic body 31, penetrating from the bottom of the recess 31c of the first elastic body 31 to the mounting end 31b.

[0076] With the above configuration, a recess 31c having a bottom is formed in the first elastic body 31 from the connection end 31a of the first elastic body 31 connected to the connection end 32b of the second elastic body 32 toward the mounting end 31b of the first elastic body 31 attached to one of the aircraft body 3 and the cabin 10.

[0077] When viewed from the up-down direction A1, the inner periphery of the recess 31c of the first elastic body 31 and the inner periphery of the opening 31d are circular, and the recess 31c and the opening 31d of the first elastic body 31 are formed concentrically. A radius B12 of the inner periphery of the recess 31c of the first elastic body 31 is larger than a radius B13 of the inner periphery of the opening 31d of the first elastic body 31.

[0078] Regarding the cross-sectional area of ​​the first elastic body 31 in a plane C1 perpendicular to the up-down direction A1, the cross-sectional area of ​​the recessed portion 31c of the first elastic body 31 is the same in each portion in the up-down direction A1, and the cross-sectional area of ​​the opening portion 31d of the first elastic body 31 is the same in each portion in the up-down direction A1. The cross-sectional area of ​​the recessed portion 31c of the first elastic body 31 is smaller than the cross-sectional area of ​​the opening portion 31d of the first elastic body 31.

[0079] (Configuration of lower limit stopper member) - 4 7, the second elastic body 32 of the lower limit stopper member 30 has a circular outer periphery when viewed in the vertical direction A1. The upper end of the second elastic body 32 is a contact portion 32a, and the lower end of the second elastic body 32 is a connecting end portion 32b. The contact portion 32a and the connecting end portion 32b of the second elastic body 32 are formed on a plane parallel to a plane C1 that is perpendicular to the vertical direction A1.

[0080] When viewed from the vertical direction A1, the radius B22 of the outer periphery of the connecting end 32b of the second elastic body 32 is the same as the radius B11 of the outer periphery of the first elastic body 31. The radius B21 of the outer periphery of the contact portion 32a of the second elastic body 32 is smaller than the radius B22 of the outer periphery of the connecting end 32b of the second elastic body 32, and the radius of the outer periphery of the second elastic body 32 becomes smaller as it approaches the contact portion 32a of the second elastic body 32.

[0081] An opening 32c penetrating from the contact portion 32a to the connecting end 32b of the second elastic body 32 is formed in the second elastic body 32. When viewed from the up-down direction A1, the inner periphery of the opening 32c of the second elastic body 32 is circular, and a radius B23 of the inner periphery of the opening 32c of the second elastic body 32 is smaller than a radius B21 of the outer periphery of the contact portion 32a of the second elastic body 32 and smaller than a radius B22 of the outer periphery of the connecting end 32b of the second elastic body 32. A radius B12 of the inner periphery of the recess 31c of the first elastic body 31 and a radius B23 of the inner periphery of the opening 32c of the second elastic body 32 are the same.

[0082] In the second elastic body 32, the radius of the outer periphery of the second elastic body 32 becomes smaller as the portion closer to the contact portion 32a of the second elastic body 32 approaches, and the radius B23 of the inner periphery of the opening 32c of the second elastic body 32 is the same throughout the entire opening 32c, so that the cross-sectional area of ​​the second elastic body 32 in a plane C1 perpendicular to the vertical direction A1 becomes smaller as the portion closer to the contact portion 32a of the second elastic body 32 approaches.

[0083] (Configuration of lower limit stopper member)-5 7, the connection end 31a of the first elastic body 31 and the connection end 32b of the second elastic body 32 are aligned and bonded together. In this case, the recess 31c of the first elastic body 31, the opening 31d of the first elastic body 31, the contact portion 32a of the second elastic body 32, the connection end 32b of the second elastic body 32, and the opening 32c of the second elastic body 32 are concentric.

[0084] The radius B11 of the outer periphery of the first elastic body 31 is the same as the radius B22 of the outer periphery of the connecting end 32b of the second elastic body 32, and the radius B12 of the inner periphery of the recess 31c of the first elastic body 31 is the same as the radius B23 of the inner periphery of the opening 32c of the second elastic body 32.

[0085] As a result, the cross-sectional area on the plane C1 of the recess 31c of the first elastic body 31 is the same as the cross-sectional area of ​​the connecting end 32b of the second elastic body 32. The cross-sectional area of ​​the opening 31d of the first elastic body 31 is larger than the cross-sectional area of ​​the connecting end 32b of the second elastic body 32.

[0086] The length L1 of the first elastic body 31 in the vertical direction A1 (the length extending from the connection end 31a of the first elastic body 31 to the mounting end 31b) is set to be longer than the length L2 of the second elastic body 32 in the vertical direction A1 (the length extending from the contact portion 32a of the second elastic body 32 to the connection end 32b).

[0087] With the above configuration, the lower limit stopper member 30 (stopper member) has a first elastic body 31 attached to one of the aircraft body 3 and the cabin 10, and a second elastic body 32 connected to the first elastic body 31 and contacting the receiving portion 36.

[0088] The second elastic body 32 has a hardness lower than that of the first elastic body 31, and is formed in a shape such that the area of ​​the contact portion 32a of the second elastic body 32 that contacts the receiving portion 36 (second portion 36b) is smaller than the area of ​​the connection end portion 32b of the second elastic body 32 that is connected to the first elastic body 31.

[0089] The contact portion 32a of the second elastic body 32 is formed on a plane parallel to a plane C1 that is perpendicular to the up-down direction A1 (the direction along the extension and contraction direction of the suspension mechanism 24). The cross-sectional area of ​​the second elastic body 32 in a plane C1 perpendicular to the vertical direction A1 (the direction along the extension and contraction direction of the suspension mechanism 24) becomes smaller toward the contact portion 32a of the second elastic body 32.

[0090] (Attachment structure of lower limit stopper member to support member) 6, the top plate portion 26c of the support member 26 is formed on a plane parallel to a plane C1 perpendicular to the up-down direction A1, and in the lower limit stopper member 30, the mounting end portion 31b of the first elastic body 31 is placed on the top plate portion 26c of the support member 26. A collar 41 is inserted into the opening 31d of the first elastic body 31 from the opening 32c of the second elastic body 32 and the recess 31c of the first elastic body 31.

[0091] The collar 41 has a cylindrical main body 41a and a ring-shaped top plate 41b connected to the upper end of the main body 41a. When the collar 41 is inserted into the opening 31d of the first elastic body 31, the top plate 41b of the collar 41 comes into contact with the bottom of the recess 31c of the first elastic body 31, and the lower end of the main body 41a of the collar 41 comes into contact with the top plate 26c of the support member 26.

[0092] In the above-described state, the bolt 42 is inserted into the collar 41 from the opening 32c of the second elastic body 32 and the recess 31c of the first elastic body 31, and protrudes downward through the opening 26g of the top plate portion 26c of the support member 26. A nut 43 is attached to the lower end of the bolt 42, and the bolt 42 and the nut 43 are tightened. As a result, the lower limit stop member 30 is attached to the support member 26, and is attached to the fuselage 3 via the support member 26 and the rear axle case 19.

[0093] The distance W3 between the connection end 31a of the first elastic body 31 and the head of the bolt 42 is shorter than the length L2 of the second elastic body 32 in the vertical direction A1 (the length extending from the contact portion 32a of the second elastic body 32 to the connection end 32b).

[0094] When the lower limit stopper member 30 is attached to the support member 26, the collar 41 prevents the bolt 42 from being tightened more than necessary, and the first elastic body 31 will not be crushed due to overtightening of the bolt 42.

[0095] With the above configuration, a bolt 42 is attached between the bottom of the recess 31c of the first elastic body 31 and one of the aircraft body 3 and the cabin 10, and the first elastic body 31 is attached to one of the aircraft body 3 and the cabin 10.

[0096] (The state in which the lower limit position of the cabin relative to the aircraft is determined by the lower limit stopper member) - 1 6, there is a gap W1 between the lower limit stopper member 30 (the contact portion 32a of the second elastic body 32) and the second portion 36b of the receiving portion 36. There is a gap W2 between the contact portion 29b of the upper limit stopper member 29 and the first portion 36a of the receiving portion 36. When the operator is on the driver's unit 9 (when the lateral rod 25 is nearly horizontal), the gap W1 is smaller than the gap W2.

[0097] As a result, when the cabin 10 moves up and down relative to the fuselage 3 due to the extension and contraction of the suspension mechanism 24, there is an upper limit regulation state in which the contact portion 29b of the upper limit stopper member 29 comes into contact with the first portion 36a of the receiving portion 36, and there is a lower limit regulation state in which the second elastic body 32 of the lower limit stopper member 30 comes into contact with the second portion 36b of the receiving portion 36. Comparing the lower limit regulation state and the upper limit regulation state, the lower limit regulation state is more likely to occur earlier than the upper limit regulation state, and the lower limit regulation state is more likely to occur more frequently than the upper limit regulation state.

[0098] (The state in which the lower limit position of the cabin relative to the aircraft is determined by the lower limit stopper member) - 2 As shown in Figure 6, when the right (left) part of the cabin 10 descends relative to the fuselage 3 due to contraction of the right (left) suspension mechanism 24, the contact portion 32a of the second elastic body 32 of the right (left) lower limit stopper member 30 comes into contact with the second portion 36b of the right (left) receiving portion 36.

[0099] The second portion 36b of the receiving portion 36 is formed on a plane parallel to a plane C1 perpendicular to the up-down direction A1. In the lower limit stopper member 30, the radius of the outer circumferential portion of the second elastic body 32 becomes smaller as the portion of the second elastic body 32 approaches the contact portion 32a, and the second elastic body 32 is tapered.

[0100] As a result, when the contact portion 32a of the second elastic body 32 of the lower limit stopper member 30 comes into contact with the second portion 36b of the receiving portion 36, the contact portion 32a of the second elastic body 32 is more likely to come into contact with the second portion 36b of the receiving portion 36 evenly with less bias.

[0101] When the cabin 10 descends further relative to the aircraft body 3, in the lower limit stopper member 30, the hardness of the second elastic body 32 is lower than the hardness of the first elastic body 31 (the second elastic body 32 is softer than the first elastic body 31), so the second elastic body 32 is mainly compressed, and the descent of the cabin 10 is mainly absorbed by the second elastic body 32.

[0102] The cross-sectional area of ​​the second elastic body 32 in a plane C1 perpendicular to the up-down direction A1 becomes smaller toward the contact portion 32a of the second elastic body 32. As a result, at the initial stage when the second elastic body 32 and the second portion 36b of the receiving portion 36 begin to contact each other, the deceleration of the descent speed of the cabin 10 is small due to the small cross-sectional area of ​​the second elastic body 32. As the contact between the second elastic body 32 and the second portion 36b of the receiving portion 36 progresses, the cross-sectional area of ​​the second elastic body 32 at the position of the second portion 36b of the receiving portion 36 gradually increases, and the deceleration of the descent speed of the cabin 10 gradually increases.

[0103] (The state in which the lower limit position of the cabin relative to the aircraft is determined by the lower limit stopper member) - 3 As shown in Figure 6, when the cabin 10 descends further relative to the fuselage 3 and the second elastic body 32 is sufficiently compressed in the lower limit stopper member 30, the first elastic body 31 is then mainly compressed, and the descent of the cabin 10 is mainly absorbed by the first elastic body 31.

[0104] In the lower limit stopper member 30, the hardness of the first elastic body 31 is higher than the hardness of the second elastic body 32 (the first elastic body 31 is harder than the second elastic body 32), so the descent speed of the cabin 10 is reduced relatively significantly.

[0105] The outer periphery of the connection end 31a of the first elastic body 31 coincides with the outer periphery of the connection end 32b of the second elastic body 32, and the inner periphery of the recess 31c of the first elastic body 31 coincides with the inner periphery of the opening 32c of the second elastic body 32. With regard to the cross-sectional area on plane C1 (see FIG. 7), the cross-sectional area of ​​the connection end 31a of the first elastic body 31 and the cross-sectional area of ​​the connection end 32b of the second elastic body 32 are the same.

[0106] As a result, in the lower limit stopper member 30, after the second elastic body 32 is sufficiently compressed, there is a smooth transition to compression of the first elastic body 31, and the descent of the cabin 10 is smoothly absorbed.

[0107] In the lower limit stopper member 30, even if the first elastic body 31 is compressed, the bottom of the recess 31c of the first elastic body 31 moves away from the top plate portion 41b of the collar 41, and the first elastic body 31 is compressed with little influence from the collar 41 and the bolt 42.

[0108] When the first elastic body 31 is compressed in the lower limit stopper member 30, the descent speed of the cabin 10 is slowed down relatively significantly, and the cabin 10 stops at the lower limit position, and the lower limit position of the cabin 10 relative to the aircraft body 3 is determined by the lower limit stopper member 30.

[0109] In this state, even if the cabin 10 further descends relative to the fuselage 3 and the first elastic body 31 attempts to be further compressed, the cabin 10 will stop as the second part 36b of the receiving portion 36 comes into contact with the bolt 42.

[0110] With the above configuration, as the suspension mechanism 24 expands and contracts, the lower limit stopper member 30 (stopper member) comes into contact with the receiving portion 36, and the lower limit stopper member 30 (stopper member) is compressed, thereby determining at least one of the lower limit position of the cabin 10 relative to the aircraft body 3 and the upper limit position of the cabin 10 relative to the aircraft body 3.

[0111] (First Alternative Embodiment of the Invention) As shown in Figure 8, the second elastic body 32 of the lower limit stopper member 30 may have a radius B22 in the portion spanning the upper and lower intermediate portion of the second elastic body 32 and the connecting end portion 32b, and may be formed so that the radius gradually decreases from the upper and lower intermediate portion of the second elastic body 32 (radius B22) toward the contact portion 32a (radius B21).

[0112] (Second Alternative Embodiment of the Invention) As shown in Figure 9, the second elastic body 32 of the lower limit stopper member 30 is formed so that the radius gradually decreases from the connection end 32b (radius B22) of the second elastic body 32 toward the upper and lower intermediate portions, and the portion of the second elastic body 32 spanning the upper and lower intermediate portions and the contact portion 32a may be formed to have a radius B21.

[0113] (Third Alternative Embodiment of the Invention) As shown in Figure 10, in the second elastic body 32 of the lower limit stopper member 30, the radius B23 of the opening 32c of the second elastic body 32 may be formed so as to gradually increase from the connection end 32b (radius B12) of the second elastic body 32 toward the contact portion 32a.

[0114] (Fourth Alternative Embodiment of the Invention) When viewed in the direction along the extension and contraction direction of the suspension mechanism 24 (the up-down direction A1), the outer periphery of the first elastic body 31 may be formed in a polygonal shape such as a triangular or quadrangular shape. When viewed in the direction along the extension and contraction direction of the suspension mechanism 24 (the up-down direction A1), the outer periphery of the second elastic body 32 may be formed in a polygonal shape such as a triangular shape or a quadrangular shape.

[0115] (Fifth Alternative Embodiment of the Invention) The collar 41 and bolt 42 may be eliminated, and a flat mounting member (not shown) may be adhered to the mounting end 31b of the first elastic body 31 of the lower limit stopper member 30, and the mounting member may be attached to the top plate portion 26c of the support member 26.

[0116] According to the above-described configuration, the recess 31c and the opening 31d of the first elastic body 31 may be eliminated, and the opening 32c of the second elastic body 32 may be eliminated. According to the above-described configuration, the opening 31d of the first elastic body 31 may be eliminated, and the recess 31c of the first elastic body 31 may be provided up to the attachment end 31b. As a result, instead of the recess 31c, an opening (not shown) having a radius B12 that is the same as the radius B23 of the inner periphery of the opening 32c of the second elastic body 32 is opened across the connection end 31a and the attachment end 31b of the first elastic body 31.

[0117] (Sixth Alternative Embodiment of the Invention) The lower limit stopper member 30 (the mounting end 31b of the first elastic body 31) may be attached facing downward to the lower surface of the second portion 36b of the receiving portion 36, and the top plate portion 26c of the support member 26 may serve as the receiving portion.

[0118] According to the above-described configuration, the lower limit stopper member 30 (first elastic body 31) is attached to the cabin 10 (frame 39), and the receiving portion (support member 26) is attached to the fuselage 3 via the rear axle case 19.

[0119] (Seventh Alternative Embodiment of the Invention) The rod portion 29a of the upper limit stopper member 29 may be extended sufficiently upward, and the first elastic body 31 and second elastic body 32, which are the same as those of the lower limit stopper member 30, may be attached to the contact portion 29b of the upper limit stopper member 29 facing downward.

[0120] According to the above-described configuration, the upper limit stopper member 29 is attached to the vehicle body 3 via the support member 26 and the rear axle case 19. The upper limit stopper member 29 has a first elastic body 31 and a second elastic body 32, and the lower limit stopper member 30 has a first elastic body 31 and a second elastic body 32.

[0121] (Eighth Alternative Embodiment of the Invention) The upper limit stopper member 29 may have its rod portion 29a extended sufficiently upward and have the same first elastic body 31 and second elastic body 32 as the lower limit stopper member 30. The upper limit stopper member 29 may be attached facing upward to the first portion 36a of the receiving portion 36. In this case, the abutment portion 29b of the upper limit stopper member 29 shown in FIG. 6 serves as the receiving portion.

[0122] According to the above-described configuration, the upper limit stopper member 29 is attached to the cabin 10 via the receiving portion 36, and the receiving portion (the contact portion 29b of the upper limit stopper member 29 shown in FIG. 6) is attached to the fuselage 3 via the support member 26 and the rear axle case 19. An upper limit stopper member 29 having a first elastic body 31 and a second elastic body 32, and a lower limit stopper member 30 having the first elastic body 31 and a second elastic body 32 are provided.

[0123] (Ninth Alternative Embodiment of the Invention) An upper limit stopper member 29 having a first elastic body 31 and a second elastic body 32 may be provided, and the lower limit stopper member 30 may be eliminated; alternatively, a lower limit stopper member 30 having a first elastic body 31 and a second elastic body 32 may be provided, and the upper limit stopper member 29 may be eliminated.

[0124] With the above configuration and the configurations of (seventh alternative embodiment of the invention) and (eighth alternative embodiment of the invention), the extension and contraction of the suspension mechanism 24 causes the upper limit stopper member 29 (lower limit stopper member 30) to come into contact with the receiving portion 36, and the upper limit stopper member 29 (lower limit stopper member 30) is compressed, thereby determining at least one of the lower limit position of the cabin 10 relative to the aircraft body 3 and the upper limit position of the cabin 10 relative to the aircraft body 3.

[0125] (Tenth 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.

[0126] The right and left rear portions of the cabin 10 may be configured to be supported on the rear of the transmission case 6 (airframe 3) by right and left suspension mechanisms 24, and the right and left front portions of the cabin 10 may be configured to be supported on the clutch housing 5 (airframe 3) by right and left suspension mechanisms 24.

[0127] (Eleventh Alternative Embodiment of the Invention) The extension direction of the suspension mechanism 24 may be set diagonally upward and forward from the body 3, diagonally upward and backward from the body 3, diagonally upward and to the right from the body 3, or diagonally upward and to the left from the body 3, instead of in the up-down direction A1.

[0128] According to the above-described configuration, the direction along the extension and contraction direction of the suspension mechanism 24 is also a diagonally upward and forward direction from the aircraft body 3, a diagonally upward and backward direction from the aircraft body 3, a diagonally upward and to the right side from the aircraft body 3, and a diagonally upward and to the left side from the aircraft body 3.

[0129] (Twelfth Alternative Embodiment of the Invention) A crawler type traveling device (not shown) may be provided as the front traveling device instead of the front wheels 1. A crawler type traveling device (not shown) may be provided as the rear traveling device instead of the rear wheels 2. The front wheels 1 and the rear wheels 2 may be configured by one crawler type traveling device (not shown). [Industrial Applicability]

[0130] 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]

[0131] 1 Front wheel (running gear) 2 Rear wheels (running gear) 3 aircraft 9 Driving Department 10 Cabins 24 Suspension mechanism 30 Stopper member 31 First elastic body 31a Connection end 31b Mounting end 31c Recess 32 Second Elastic Body 32a Hitting part 32b Connection end 32c opening 36 Receiving part 42 volts A1 direction B11 Radius B22 radius C1 side L1 length L2 length

Claims

1. a machine body supported by a running gear; a driver's section in which an operator rides; a cabin that houses the driver's section; a suspension mechanism that supports the cabin on the airframe; a stopper member attached to one of the airframe and the cabin; a receiving portion attached to the other of the fuselage and the cabin, the stopper member comes into contact with the receiving portion and is compressed by the extension and contraction of the suspension mechanism, thereby determining at least one of a lower limit position of the cabin relative to the airframe and an upper limit position of the cabin relative to the airframe, the stopper member has a first elastic body attached to one of the airframe and the cabin, and a second elastic body connected to the first elastic body and abutting against the receiving portion, the second elastic body has a hardness lower than that of the first elastic body, and is formed in a shape such that an area of ​​a contact portion of the second elastic body that contacts the receiving portion is smaller than an area of ​​a connection end portion of the second elastic body that is connected to the first elastic body, a cross-sectional area of ​​the second elastic body in a plane perpendicular to a direction along the extension and contraction direction of the suspension mechanism becomes smaller as the cross-sectional area of ​​the second elastic body becomes smaller toward the contact portion, an outer periphery of the second elastic body is circular when viewed from a direction along the extension and contraction direction of the suspension mechanism; The radius of the outer circumferential portion of the second elastic body becomes smaller as the portion of the second elastic body becomes closer to the contact portion, an outer periphery of the first elastic body is circular when viewed from a direction along the extension and contraction direction of the suspension mechanism; A work vehicle in which the radius of the outer periphery of the first elastic body is the same as the radius of the outer periphery of the connecting end of the second elastic body.

2. 2. A work vehicle according to claim 1, wherein the length of the first elastic body in the direction along the extension and contraction direction of the suspension mechanism is longer than the length of the second elastic body in the direction along the extension and contraction direction of the suspension mechanism.

3. 2. The work vehicle according to claim 1, wherein the contact portion of the second elastic body is formed on a plane parallel to a plane perpendicular to the direction along the extension and contraction direction of the suspension mechanism.

4. 2. The work vehicle according to claim 1, wherein the second elastic body has an opening formed therein that penetrates from the contact portion of the second elastic body to the connecting end portion of the second elastic body.

5. 5. The work vehicle according to claim 4, wherein a recess having a bottom is formed in the first elastic body from the connection end of the first elastic body connected to the connection end of the second elastic body toward the attachment end of the first elastic body attached to one of the machine body and the cabin.

6. 6. The work vehicle according to claim 5, wherein a bolt is attached between the bottom of the recess of the first elastic body and one of the machine body and the cabin, and the first elastic body is attached to one of the machine body and the cabin.

7. 7. The work vehicle according to claim 1, wherein the first elastic body and the second elastic body are made of urethane.

8. 8. A work vehicle according to claim 7, wherein the second elastic body is urethane foam.

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