Patent Description:
A tractor, which is an example of a work vehicle, may have a cabin supported by the body of the tractor via left and right suspension mechanisms, as disclosed in <CIT>. The tractor of <CIT> has lateral rods, which are connected to the body and the cabin, and the lateral rods allow the cabin to move upward and downward relative to the body and restrain the cabin from moving leftward and rightward relative to the body. The cabin of the work vehicle includes an operation section for an operator to board, and has a relatively large lateral width. In the case where the body supports the cabin via the suspension mechanisms, there is room for improvement in stably restraining the cabin from moving leftward and rightward with use of the lateral rods. The present invention provides a work vehicle having a cabin supported by the body of the vehicle via suspension mechanisms in such a manner as to stably restrain the cabin from moving leftward and rightward with use of lateral rods.

A work vehicle of the present invention comprises:.

According to the present invention, the body supports the cabin via the left and right suspension mechanisms, and the left and right lateral rods are provided. These lateral rods stably restrain the cabin from moving leftward and rightward even if the cabin has a relatively large lateral width. The right lateral rod is disposed rightward and laterally outward of the right suspension mechanism, and is connected to the right portion of the cabin. Also, the left lateral rod is disposed leftward and laterally outward of the left suspension mechanism, and is connected to the left portion of the cabin. This separates the left and right lateral rods from each other in the left-right direction, which is advantageous in terms of stably by the lateral rods restraining the cabin from moving leftward and rightward.

In one preferred embodiment of the work vehicle of the present invention,.

According to the present invention, upon the operator boarding the operation section, the weight of the operator causes the suspension mechanisms to contract, and the left and right lateral rods extend in a direction close to a horizontal direction. The suspension mechanisms extending and contracting in this state swing the lateral rods upward and downward from a position of the lateral rods extending in the direction close to a horizontal direction. This is advantageous in terms of stably by the lateral rods restraining the cabin from moving leftward and rightward.

In one preferred embodiment of the present invention, the work vehicle further comprises:.

According to the present invention, the right elastic body defines a limit of contraction of the right suspension mechanism. Also, according to the present invention, the left elastic body defines a limit of contraction of the left suspension mechanism. Thus, if the right portion of the cabin is lowered relative to the body and the right suspension mechanism contracts, the right elastic body is configured to restrain the right portion of the cabin from being lowered unnecessarily. Further, if the left portion of the cabin is lowered relative to the body and the left suspension mechanism contracts, the left elastic body is configured to restrain the left portion of the cabin from being lowered unnecessarily. In this case, the right elastic body restrains the right portion of the cabin from moving downward while being elastically deformed, and the left elastic body restrains the left portion of the cabin from moving downward while being elastically deformed. This makes a shock unlikely to occur and improves ride quality for the operator in the operation section.

The operator in the operation section rarely feels uncomfortable about downward movement of either one of the left and right portions of the cabin, but may feel uncomfortable about upward movement of the other one of the left and right portions of the cabin. In other words, the operator in the operation section rarely feel uncomfortable about contraction of either one of the left and right suspension mechanisms, but may feel uncomfortable about extension of the other one of the left and right suspension mechanisms. According to the present invention, providing the rebound springs in the suspension mechanisms make it difficult for the left and right suspension mechanisms to extend, and make it difficult for the left and right portions of the cabin to move upward. The rebound springs make it difficult for the left and right suspension mechanisms to extend, and also make it difficult for the left and right portions of the cabin to move upward, thereby also suppressing rolling of the cabin relative to the body. This improves ride quality for the operator in the operation section.

In a work device such as a tractor, there are cases where a link mechanism for supporting a work device is located at a rear portion of the body and extends rearward. The link mechanism (work device) is raised and lowered by providing the lift arm at the rear portion of the body which lift arm raises and lowers the link mechanism, connecting the lift cylinder to the body and lift arm, and raising and lowering the lift arm with the lift cylinder. According to the present invention, the left and right suspension mechanisms are disposed leftward and rightward, respectively, and laterally outward of the lift arm and the lift cylinder, and respectively support the rear left and right portions of the cabin. The left and right suspension mechanisms are thus separated from each other in the left and right direction, and stably support the cabin. Further, the left and right lateral rods are disposed leftward and rightward, respectively, and laterally outward of the left and right suspension mechanisms, the lift arm, and the lift cylinder. With this, interference between the lateral rods, the lift arm, and the lift cylinder can be avoided.

In a work device such as a tractor, the left and right rear axle cases extend leftward and rightward, respectively, and laterally outward from the rear portion of the body, and the rear axle cases hold the left and right travel devices (e.g. rear wheels or crawler travel devices). According to the present invention, the right lateral rod is connected to the rear right portion of the cabin and the right rear axle case. Also, the left lateral rod is connected to the rear left portion of the cabin and the left rear axle case. The lateral rods are connected to the body via the rear axle cases. The left and right lateral rods can be disposed leftward and rightward, respectively, and laterally outward of the left and right suspension mechanisms, the lift arm, and the lift cylinder without difficulty by effectively using the rear axle cases extending leftward and rightward and laterally outward from the body.

According to the present invention, the right lateral rod is connected to the right rear axle case, and the right portion of the right lateral rod is located within the right travel device. The left lateral rod is connected to the left rear axle case, and the left portion of the left lateral rod is located within the left travel device. This allows long lateral rods to be easily obtained, and is, therefore, advantageous in terms of stably restraining the cabin from moving leftward and rightward with use of the lateral rods. Further, with this configuration, the right travel device covers the right portion of the right lateral rod, and the left travel device covers the left portion of the left lateral rod. This makes it difficult for mud, dust, or the like to stick to the right portion of the right lateral rod and the left portion of the left lateral rod. This reduces the likelihood that stuck mud, dust, or the like impedes movement of the lateral rods, and is, therefore, advantageous in terms of stably restraining the cabin from moving leftward and rightward with use of the lateral rods.

According to the present invention, the right suspension mechanism supports the rear right portion of the cabin, and the right lateral rod is disposed between the cabin and the right suspension mechanism. The left suspension mechanism supports the rear left portion of the cabin, and the left lateral rod is disposed between the cabin and the left suspension mechanism. This enables the lateral rods to be disposed with effective use of spaces between the cabin and the suspension mechanisms, and can thus realize space-saving in the placement of the lateral rods.

According to the present invention, the right suspension mechanism is connected to the rear right portion of the cabin and the right rear axle case. The left suspension mechanism is connected to the rear left portion of the cabin and the left rear axle case. With this configuration, the suspension mechanisms are connected to the body via the rear axle cases. The left and right suspension mechanisms can be disposed leftward and rightward, respectively, and laterally outward of the lift arm and the lift cylinder without difficulty by effectively using the rear axle cases extending leftward and rightward, and laterally outward from the body.

According to the present invention, the support members are used as both members for connecting the suspension mechanisms to the rear axle cases and members for connecting the lateral rods to the rear axle cases, due to the suspension mechanisms and the lateral rods being connected to the rear axle cases via common support members. This is advantageous in terms of simplifying the structure.

According to the present invention, the work vehicle has the right lower limit stopper and the left lower limit stopper. The right lower limit stopper defines the lower limit position of upward and downward movement of the rear right portion of the cabin relative to the body. The left lower limit stopper defines the lower limit position of upward and downward movement of the rear left portion of the cabin relative to the body. This configuration restrains the rear left and right portions of the cabin from unnecessarily moving downward. The lower limit stoppers are attached to the support members. The support members are used as members for attaching the lower limit stoppers to the rear axle cases. This is advantageous in terms of simplifying the structure. In this case, if the suspension mechanisms include the elastic bodies that define the limit of contraction of the aforementioned suspension mechanisms, cooperation of the elastic bodies and the lower limit stoppers stably restrains the left and right portions of the cabin from unnecessarily moving downward, with less shock.

According to the present invention, the work vehicle includes the right upper limit stopper and the left upper limit stopper. The right upper limit stopper defines the upper limit position of upward and downward movement of the rear right portion of the cabin relative to the body. The left upper limit stopper that defines the upper limit position of upward and downward movement of the rear left portion of the cabin relative to the body. This configuration restrains the rear left and right portions of the cabin from unnecessarily moving upward. The upper limit stoppers are attached to the support members. The support members are used as members for attaching the upper limit stoppers to the rear axle cases. This is advantageous in terms of simplifying the structure. In this case, with the aforementioned rebound springs provided in the suspension mechanisms, cooperation of the rebound springs and the upper limit stoppers stably restrains the left and right portions of the cabin from unnecessarily moving upward, with less shock.

According to the present invention, when the support members are attached to the rear axle cases, the fixing members are prepared, and the support members are attached to the rear axle cases by coupling the support members to the fixing members with the rear axle cases held between the support members and the fixing members. In a work vehicle such as a tractor in which the link mechanism for holding the work device is provided at a rear portion of the body of the vehicle and extend rearward, a configuration that prevents displacement (shake) of the link mechanism in the left-right direction may be provided. The restraint rods are connected to the link mechanism and the fixing members and restrain the link mechanism from being displaced (shaken) in the left-right direction. The fixing members are also used as members for attaching the restraint rods to the rear axle cases, which is advantageous in terms of simplifying the structure.

Embodiments of the invention will now be described with reference to the accompanying drawings in which:.

Modes for carrying out the present invention will be described with reference to the drawings showing a tractor as an example of a work vehicle. When defining a front-back direction of the work vehicle in the embodiment, it is defined along a travelling direction of a body of the work vehicle, and when defining the left-right direction of the work vehicle, left and right are defined as seen in the travelling direction view of the body. That is, an "F" arrow as shown in <FIG> indicates forward of the body, a "B" arrow as shown in <FIG> indicates backward of the body, a "L" arrow as shown in <FIG> indicates leftward of the body and a "R" arrow as shown in <FIG> indicates rightward of the body. Therefore, the left and right directions of the body correspond to the width direction of the body.

As shown in <FIG>, left and right front wheels <NUM> and left and right rear wheels <NUM> support a body <NUM> of the tractor. The body <NUM> has an engine <NUM>, a clutch housing <NUM> coupled to a rear portion of the engine <NUM>, a transmission case <NUM> coupled to a rear portion of the clutch housing <NUM>, a front frame <NUM> coupled to a front portion of the engine <NUM>, and so on. Each of the left and right front wheels <NUM> and the left and right rear wheels <NUM> corresponds to a "travel device" recited in the claims.

The front frame <NUM> holds the front wheels <NUM>. Left and right rear axle cases <NUM> are coupled to a rear portion of the transmission case <NUM> (body <NUM>) and extend leftward and rightward, respectively, and laterally outward from the rear portion of the transmission case <NUM> (body <NUM>), as shown in <FIG> and <FIG>. The left and right rear axle cases <NUM> hold the left and right rear wheels <NUM>.

A hood <NUM> is provided at a front portion of the body <NUM>, as shown in <FIG>. The hood <NUM> covers the engine <NUM>. An operation section <NUM> for an operator to board is provided at a rear portion of the body <NUM>. The operation section <NUM> is accommodated in a cabin <NUM>. The operation section <NUM> includes an operation seat <NUM> and a steering handle <NUM> with which the operator steers the front wheels <NUM>.

One top link <NUM> and left and right lower links <NUM> are provided at the rear portion of the transmission case <NUM> (body <NUM>) and swingable upward and downward, as shown in <FIG>, <FIG>, and <FIG>. The top link <NUM> and the lower links <NUM> extend rearward. The top link <NUM> and the lower links <NUM> constitute a link mechanism <NUM> of a three-point link type. A work device, such as a rotary tilling device (not shown) or a plow (not shown), is connected to and held by the link mechanism <NUM>.

A PTO shaft <NUM> is provided at the rear portion of the transmission case <NUM> (body <NUM>). Motive power from the PTO shaft <NUM> is transferred, via a transfer shaft (not shown), to the work device held by the link mechanism <NUM>. Left and right cover members <NUM>, each having a flat plate shape, are coupled to the rear portion of the transmission case <NUM> (body <NUM>). The cover member <NUM> is coupled to the left and right cover members <NUM>. The cover members <NUM> and <NUM> cover the PTO shaft <NUM> from the laterally outer sides and from above.

Left and right lift arms <NUM> are provided at an upper portion of the transmission case <NUM> (body <NUM>) and swingable upward and downward. Left and right lift cylinders <NUM> are connected to the corresponding lift arms <NUM> and the corresponding cover members <NUM>. The lift cylinders <NUM> are connected to the transmission case <NUM> (body <NUM>) via the cover members <NUM>.

Link rods <NUM> are connected to the corresponding lift arms <NUM> and the corresponding lower links <NUM>. The lower links <NUM> (link mechanism <NUM>) and the work device are raised and lowered as a result of the lift arms <NUM> being raised and lowered by the lift cylinders <NUM>.

The clutch housing <NUM> (body <NUM>) supports a front right portion of the cabin <NUM> via a right vibration isolation rubber <NUM>, as shown in <FIG>, <FIG>, and <FIG>. The clutch housing <NUM> (body <NUM>) supports a front left portion of the cabin <NUM> via a left vibration isolation rubber <NUM>. The body <NUM> supports a rear right portion of the cabin <NUM> via a right suspension mechanism <NUM>. The body <NUM> supports a rear left portion of the cabin <NUM> via a left suspension mechanism <NUM>.

With this, the suspension mechanisms <NUM> move the rear portion of the cabin <NUM> upward and downward relative to the body <NUM> with a front lower portion (vibration isolation rubbers <NUM>) of the cabin <NUM> as a fulcrum. The tractor has left and right lateral rods <NUM>. The left and right lateral rods <NUM> allow the cabin <NUM> to move upward and downward relative to the body <NUM> and restrain the cabin <NUM> from moving leftward and rightward relative to the body <NUM>.

The tractor has left and right support members <NUM> and left and right fixing members <NUM>, as shown in <FIG> and <FIG>.

The support members <NUM> abut against upper faces of the corresponding rear axle cases <NUM>, as shown in <FIG>, <FIG>, and <FIG>. The fixing members <NUM> abut against lower faces of the corresponding rear axle cases <NUM>. The support members <NUM> and the fixing members <NUM> hold the corresponding rear axle cases <NUM> therebetween. Four bolts <NUM> are attached and fastened to the support members <NUM> and the fixing members <NUM>.

The support members <NUM> and the fixing members <NUM> are coupled by the bolts <NUM> with the rear axle cases <NUM> being held between the support members <NUM> and the fixing members <NUM>. With this configuration, the right support member <NUM> and the right fixing member <NUM> are attached to the right rear axle case <NUM>. Also, with this configuration, the left support member <NUM> and the left fixing member <NUM> are attached to the left rear axle case <NUM>.

Each support member <NUM> includes a base 26a having a flat plate shape. Four types of brackets 26b, 26c, 26d, and 26e are provided on the base 26a. The left and right support members <NUM> have laterally symmetrical shapes.

The bracket 26c of the right support member <NUM> is located within a wheel 2a of the right rear wheel <NUM> in such a manner as to overlap the wheel 2a of the right rear wheel <NUM> in a back view, as shown in <FIG>. The bracket 26c of the left support member <NUM> is located within a wheel 2a of the left rear wheel <NUM> in such a manner as to overlap the wheel 2a of the left rear wheel <NUM> in a back view.

The tractor has left and right lower limit stoppers <NUM> and left and right upper limit stoppers <NUM> that are made of hard rubber, as shown in <FIG>, <FIG>, and <FIG>. The right lower limit stopper <NUM> is attached to the bracket 26d of the right support member <NUM>. The left lower limit stopper <NUM> is attached to the bracket 26d of the left support member <NUM>. The right upper limit stopper <NUM> is attached to the bracket 26e of the right support member <NUM>. The left upper limit stopper <NUM> is attached to the bracket 26e of the left support member <NUM>. Each upper limit stopper <NUM> includes a rod section 30a and a receiver section 30b having a flat plate shape attached to an upper portion of the rod section 30a. A lower portion of the rod section 30a is attached to the bracket 26e of the support member <NUM>.

Each fixing member <NUM> has a base 27a having a flat plate shape. A bracket 27b is provided on the base 27a. The left and right fixing members <NUM> have laterally symmetrical shapes. The tractor has left and right restraint rods <NUM>, as shown in <FIG>, <FIG>, and <FIG>. The right restraint rod <NUM> is connected to the right lower link <NUM> (link mechanism <NUM>) and the bracket 27b of the right fixing member <NUM>. The left restraint rod <NUM> is connected to the left lower link <NUM> (link mechanism <NUM>) and the bracket 27b of the left fixing member <NUM>. The restraint rods <NUM> restrain the link mechanism <NUM> from being displaced (shaken) in the left-right direction.

Left and right frames <NUM> are coupled, in the front-back direction, respectively to lower left and right portions of the cabin <NUM>, as shown in <FIG> and <FIG>. A right frame <NUM> is coupled to the rear right portion of the cabin <NUM> and a rear portion of the corresponding frame <NUM>. A left frame <NUM> is coupled to the rear left portion of the cabin <NUM> and a rear portion of the corresponding frame <NUM>. The frames <NUM> and <NUM> are parts of the cabin <NUM>. Left and right rear wheel fenders <NUM> are attached to the frames <NUM> and <NUM>. Left and right brackets <NUM> are coupled to the frames <NUM> and extend rearward.

The right suspension mechanism <NUM> is connected to the right bracket <NUM> and the bracket 26b of the right support member <NUM>, as shown in <FIG>, <FIG>, and <FIG>. The left suspension mechanism <NUM> is connected to the left bracket <NUM> and the bracket 26b of the left support member <NUM>.

With the above configuration, the right suspension mechanism <NUM> is located rightward and laterally outward of the right lift arm <NUM> and the right lift cylinder <NUM> in a back view, as shown in <FIG>. The right suspension mechanism <NUM> is connected to the rear right portion of the cabin <NUM> and the right rear axle case <NUM>. A lower portion of the right suspension mechanism <NUM> is connected to the rear portion of the transmission case <NUM> (body <NUM>) via the right rear axle case <NUM>.

The left suspension mechanism <NUM> is located leftward and laterally outward of the left lift arm <NUM> and the left lift cylinder <NUM> in a back view. The left suspension mechanism <NUM> is connected to the rear left portion of the cabin <NUM> and the left rear axle case <NUM>. A lower portion of the left suspension mechanism <NUM> is connected to the rear portion of the transmission case <NUM> (body <NUM>) via the right rear axle case <NUM>.

The left and right suspension mechanisms <NUM> each have a suspension spring <NUM>, a damper <NUM>, an elastic body <NUM>, a rebound spring <NUM>, and so on, as shown in <FIG>.

The damper <NUM> is of a single-tube type. The damper <NUM> has an outer cylinder 39a, a piston rod 39b, a piston 39c, a free piston 39d, and so on. The piston 39c, which has a piston valve (orifice) (not shown), is attached to a lower portion of the piston rod 39b within the outer cylinder 39a. The free piston 39d is located at a lower portion of the outer cylinder 39a, within the outer cylinder 39a. This constitutes an oil chamber 39e and a gas chamber 39f within the outer cylinder 39a.

A spring receiver <NUM> is coupled to an upper portion of the piston rod 39b of the damper <NUM>. A spring receiver <NUM> is coupled to the outer cylinder 39a of the damper <NUM>. The suspension spring <NUM> is attached to the spring receiver <NUM> and the spring receiver <NUM>. A cover <NUM> that covers the suspension spring <NUM> is attached to the spring receiver <NUM>.

The elastic body <NUM> is made of synthetic rubber, urethane, or the like, and has a cylindrical shape (ring shape). The elastic body <NUM> is located between an upper end of the outer cylinder 39a of the damper <NUM> and the spring receiver <NUM>, and is attached to the piston rod 39b of the damper <NUM>. The rebound spring <NUM> is attached to the upper end of the outer cylinder 39a of the damper <NUM> and the piston 39c, within the outer cylinder 39a of the damper <NUM>.

In each suspension mechanism <NUM> configured as described above, an upper end of the piston rod 39b of the damper <NUM> is attached to the corresponding bracket <NUM> (see <FIG>, <FIG>, and <FIG>), and a lower end of the outer cylinder 39a of the damper <NUM> is attached to the bracket 26b of the corresponding support member <NUM>.

The tractor has left and right receiver plates <NUM>, each of which is a plate material bent in a crank shape, as shown in <FIG>, <FIG>, and <FIG>. Each receiver plate <NUM> is coupled to a rear portion of the corresponding frame <NUM>. The tractor has left and right brackets <NUM>. Each bracket <NUM> is coupled to the rear portion of the corresponding frame <NUM>.

The tractor has left and right lateral rods <NUM>. The right lateral rod <NUM> is connected to the right bracket <NUM> and the bracket 26c of the right support member <NUM>. The right lateral rod <NUM> is located between the brackets 26b and 26d of the right support member <NUM>.

The left lateral rod <NUM> is connected to the left bracket <NUM> and the bracket 26c of the left support member <NUM>. The left lateral rod <NUM> is located between the brackets 26b and 26d of the left support member <NUM>.

The right lateral rod <NUM> extends rightward and laterally outward in an obliquely downward direction from the right bracket <NUM> (the rear right portion of the cabin <NUM>) due to the configuration of the right suspension mechanism <NUM>, while the operator is not in the operation section <NUM>, as shown in <FIG> and <FIG>. The right lateral rod <NUM> is connected to the bracket 26c of the right support member <NUM>.

The left lateral rod <NUM> extends leftward and laterally outward in an obliquely downward direction from the left bracket <NUM> (the rear left portion of the cabin <NUM>) due to the configuration of the left suspension mechanism <NUM>, while the operator is not in the operation section <NUM>. The left lateral rod <NUM> is connected to the bracket 26c of the left support member <NUM>.

Upon the operator entering the operation section <NUM>, the suspension mechanisms <NUM> slightly contract due to the weight of the operator, and the orientations of the left and right lateral rods <NUM> shifts from the orientations shown in <FIG> and <FIG> to orientations close to a horizontal orientation.

If, in the above state, the right suspension mechanism <NUM> contracts, i.e. if the rear right portion of the cabin <NUM> moves upward or downward, the right lateral rod <NUM> swings upward or downward from the orientation close to a horizontal direction, with the bracket 26c of the right support member <NUM> as a fulcrum. Also, if, in the above state, the left suspension mechanism <NUM> contracts, i.e. the rear left portion of the cabin <NUM> moves upward or downward, the left lateral rod <NUM> moves upward or downward from the orientation close to a horizontal direction, with the bracket 26c of the left support member <NUM> as a fulcrum. That is, the left and right lateral rods <NUM> allow the cabin <NUM> to move upward and downward relative to the body <NUM>. This restrains the cabin <NUM> from moving leftward and rightward relative to the body <NUM>.

With above configuration, the right lateral rod <NUM> is located rightward and laterally outward of the right suspension mechanism <NUM> and connected to the right portion of the cabin <NUM> in a back view, as shown in <FIG>. The left lateral rod <NUM> is located leftward and laterally outward of the left suspension mechanism <NUM> and connected to the left portion of the cabin <NUM> in a back view.

The right lateral rod <NUM> is connected to the rear right portion of the cabin <NUM> and the bracket 26c of the right support member <NUM>. A right portion of the right lateral rod <NUM> is connected to the right rear axle case <NUM> via the right support member <NUM>.

The left lateral rod <NUM> is connected to the rear left portion of the cabin <NUM> and the bracket 26c of the left support member <NUM>. A left portion of the left lateral rod <NUM> is connected to the left rear axle case <NUM> via the left support member <NUM>.

The right portion of the right lateral rod <NUM> is located within the wheel 2a of the right rear wheel <NUM> in such a manner as to overlap the wheel 2a of the right rear wheel <NUM> in a back view. In other words, the bracket 26c of the right support member <NUM> is located within the wheel 2a of the right rear wheel <NUM> in such a manner as to overlap the wheel 2a of the right rear wheel <NUM> in a back view.

The left portion of the left lateral rod <NUM> is located within the wheel 2a of the left rear wheel <NUM> in such a manner as to overlap the wheel 2a of the left rear wheel <NUM> in a back view. In other words, the bracket 26c of the left support member <NUM> is located within the wheel 2a of the left rear wheel <NUM> in such a manner as to overlap the wheel 2a of the left rear wheel <NUM> in a back view.

The right lateral rod <NUM> is located forward of the right suspension mechanism <NUM> in a side view, as shown in <FIG> and <FIG>. The right lateral rod <NUM> is located between the cabin <NUM> and the right suspension mechanism <NUM> in the front-back direction. The left lateral rod <NUM> is located forward of the left suspension mechanism <NUM> in a side view. The left lateral rod <NUM> is located between the cabin <NUM> and the left suspension mechanism <NUM> in the front-back direction.

The right lower limit stopper <NUM> is attached to the bracket 26d of the right support member <NUM>, as shown in <FIG>, <FIG>, and <FIG>. The right lower limit stopper <NUM> is located below the right receiver plate <NUM>. The left lower limit stopper <NUM> is attached to the bracket 26d of the left support member <NUM>. The left lower limit stopper <NUM> is located below the left receiver plate <NUM>.

The left and right receiver plates <NUM> each have an opening section 36a. The rod sections 30a of the left and right upper limit stoppers <NUM> penetrates the opening sections 36a of the corresponding receiver plates <NUM>. The receiver section 30b of each upper limit stopper <NUM> has a diameter larger than the diameter of the opening section 36a of the receiver plate <NUM>.

With the above configuration, the position of the right lower limit stopper <NUM> is the lower limit position of the upward and downward movement of the rear right portion of the cabin <NUM> relative to the body <NUM>. When the right suspension mechanism <NUM> contracts and the rear right portion of the cabin <NUM> is lowered, the upper end of the outer cylinder 39a of the damper <NUM> comes into contact with the right elastic body <NUM> and compresses the right elastic body <NUM> in the right suspension mechanism <NUM>, as shown in <FIG>, slightly before the right receiver plate <NUM> comes into contact with the right lower limit stopper <NUM>. The right receiver plate <NUM> comes into contact with the right lower limit stopper <NUM> with the right elastic body <NUM> being compressed. The right elastic body <NUM> and the right lower limit stopper <NUM> restrain the rear right portion of the cabin <NUM> from moving downward.

The position of the left lower limit stopper <NUM> is the lower limit position of the upward and downward movement of the rear left portion of the cabin <NUM> relative to the body <NUM>. When the left suspension mechanism <NUM> contracts and the rear left portion of the cabin <NUM> is lowered, the upper end of the outer cylinder 39a of the damper <NUM> comes into contact with the left elastic body <NUM> and compresses the left elastic body <NUM> in the left suspension mechanism <NUM>, as shown in <FIG>, slightly before the left receiver plate <NUM> comes into contact with the left lower limit stopper <NUM>. The left receiver plate <NUM> comes into contact with the left lower limit stopper <NUM> with the left elastic body <NUM> being compressed. The left elastic body <NUM> and the left lower limit stopper <NUM> restrain the rear left portion of the cabin <NUM> from moving downward.

The right receiver plate <NUM> is configured to come into contact with the right lower limit stopper <NUM> when the right elastic body <NUM> is compressed and reaches a contraction limit at which the elastic body <NUM> is no longer compressed even while receiving a compressive force. This enables the right elastic body <NUM> to absorb a shock while being compressed, and the right elastic body <NUM> reaching the contraction limit restrains the rear right portion of the cabin <NUM> from moving downward. This suppresses a shock while the right receiver plate <NUM> comes into contact with the right lower limit stopper <NUM>. The left receiver plate <NUM> is configured to come into contact with the left lower limit stopper <NUM> when the left elastic body <NUM> is compressed and reaches a contraction limit. This enables the left elastic body <NUM> to absorb a shock while being compressed, and the left elastic body <NUM> reaching the contraction limit restrains the rear left portion of the cabin <NUM> from moving downward. This suppresses a shock while the left receiver plate <NUM> comes into contact with the left lower limit stopper <NUM>.

When the right suspension mechanism <NUM> contracts, the piston 39c of the damper <NUM> in the right suspension mechanism <NUM> moves in a direction away from the rebound spring <NUM> (downward), as shown in <FIG>. Thus, the right rebound spring <NUM> is not compressed and does not apply resistance to the contraction of the right suspension mechanism <NUM>. When the left suspension mechanism <NUM> contracts, the piston 39c of the damper <NUM> in the left suspension mechanism <NUM> moves in a direction away from the rebound spring <NUM> (downward). Thus, the left rebound spring <NUM> is not compressed and does not apply resistance to the contraction of the left suspension mechanism <NUM>.

The position of the receiver section 30b of the right upper limit stopper <NUM> is the upper limit position of the upward and downward movement of the rear right portion of the cabin <NUM> relative to the body <NUM>. When the rear right portion of the cabin <NUM> is raised, the right receiver plate <NUM> comes into contact with the receiver section 30b of the right upper limit stopper <NUM> and thus restrains the rear right portion of the cabin <NUM> from moving upward.

The position of the receiver section 30b of the left upper limit stopper <NUM> is the upper limit position of the upward and downward movement of the rear left portion of the cabin <NUM> relative to the body <NUM>. When the rear left portion of the cabin <NUM> is raised, the left receiver plate <NUM> comes into contact with the receiver section 30b of the left upper limit stopper <NUM> and thus restrains the rear left portion of the cabin <NUM> from moving upward.

When the right suspension mechanism <NUM> extends, the piston 39c of the damper <NUM> in the right suspension mechanism <NUM> moves in a direction approaching the rebound spring <NUM> (upward), as shown in <FIG>. Thus, the piston 39c of the damper <NUM> compresses the rebound spring <NUM>, and the right rebound spring <NUM> applies resistance to the extension of the right suspension mechanism <NUM>. When the left suspension mechanism <NUM> extends, the piston 39c of the damper <NUM> in the left suspension mechanism <NUM> moves in a direction approaching the rebound spring <NUM> (upward), as shown in <FIG>. Thus, the piston 39c of the damper <NUM> compresses the rebound spring <NUM>, and the left rebound spring <NUM> applies resistance to the extension of the left suspension mechanism <NUM>.

While the right suspension mechanism <NUM> is extending, the right rebound spring <NUM> absorbs a shock while being compressed. This suppresses a shock occurring in response to the right receiver plate <NUM> coming into contact with the receiver section 30b of the right upper limit stopper <NUM>. While the left suspension mechanism <NUM> is extending, the left rebound spring <NUM> absorbs a shock while being compressed. This suppresses a shock occurring in response to the left receiver plate <NUM> coming into contact with the receiver section 30b of the left upper limit stopper <NUM>.

The rear section of the transmission case <NUM> (body <NUM>) may alternatively support the rear left and right portions of the cabin <NUM> via the left and right vibration isolation rubbers <NUM>. The clutch housing <NUM> (body <NUM>) may alternatively support the front left and right portions of the cabin <NUM> via the left and right suspension mechanisms <NUM>.

The rear axle cases <NUM> may hold crawler travel devices (not shown) serving as travel device, instead of the rear wheels <NUM>.

In <FIG>, the elastic body <NUM> may be connected to the upper end of the outer cylinder 39a of each damper <NUM> and the corresponding spring receiver <NUM> without a gap from the upper end of the outer cylinder 39a of the damper <NUM>. The material of the elastic body <NUM> is not limited to synthetic rubber or urethane, and may alternatively be a metal short coil spring (not shown).

Claim 1:
A work vehicle, comprising:
an operation section (<NUM>) occupiable by an operator;
a cabin (<NUM>) accommodating the operation section (<NUM>);
left and right suspension mechanisms (<NUM>) via which a body (<NUM>) of the work vehicle supports a left portion and a right portion of the cabin (<NUM>); and
left and right lateral rods (<NUM>) configured to allow the cabin (<NUM>) to move upward and downward relative to the body (<NUM>) and restrain the cabin (<NUM>) from moving leftward and rightward relative to the body (<NUM>),
and characterised in that the right lateral rod (<NUM>) is disposed rightward and laterally outward of the right suspension mechanism (<NUM>) and is connected to the right portion of the cabin (<NUM>), and
the left lateral rod (<NUM>) is disposed leftward and laterally outward of the left suspension mechanism (<NUM>) and is connected to the left portion of the cabin (<NUM>).