JPH11268665A - Work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a swing of a cabin from becoming larger by making a suspension which supports a cabin to be switchable between a suspension activated condition and suspension locked condition. SOLUTION: An active type suspension SS is configured to be switchable between a suspension activated condition and a suspension locked condition. Running condition detection means 101 is provided with a supersonic sensor S4 as a road condition detection sensor for detecting irregularity of the running surface, and is configured so that it determines whether it is in a road running condition or in a working road running condition. In other words, if the irregularity of the running road is large such as a working place with a surface of soil, the amplitude of reflecting wave from the running surface is small. Contrary, if the irregularity of the running road is small such as an asphalt paved road, the amplitude of reflecting wave from the running surface is large. This enables the determination of the running conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work vehicle in which a cabin for driving or the like is supported on a vehicle body.

[0002]

2. Description of the Related Art In the above working vehicle, a cabin is supported on a vehicle body by a suspension having a shock absorber (for example, see US Pat.
43584).

[0003]

In the prior art described above, even when a work vehicle travels on a work site having an uneven surface, vibration of the vehicle body caused by the unevenness of the work site is absorbed by the suspension, so that the inside of the cabin is reduced. This improves the ride comfort of the driver. However, according to the above-described conventional technology, when the work vehicle travels on a work site having a large degree of surface unevenness and the vehicle body shakes greatly, the swing of the cabin becomes large due to the suspension, and on the contrary, There was a problem that the ride quality was reduced. The present invention has been made in view of the above circumstances, and an object thereof is to provide a work vehicle in which a cabin is supported on a vehicle body by a suspension, for example, when traveling on a work site having a large degree of surface unevenness, and When driving,
An object of the present invention is to make it possible to switch the effectiveness of the suspension so as to eliminate the above-mentioned disadvantages of the related art.

[0004]

According to the first aspect of the present invention, the suspension supporting the cabin is configured to be operable to switch between a suspension operating state and a suspension locked state. Therefore, for example, when traveling on a road surface with a small degree of surface irregularities, when the suspension is switched to the suspension operation state, the surface irregularities are absorbed by the suspension and are not transmitted to the cabin, and the vehicle can be driven with a good ride comfort, For example, when traveling on a work site with a large degree of unevenness on the surface, the suspension is switched to the suspension lock state, so that when the vehicle body shakes due to unevenness on the work site, the swing of the cabin is prevented from becoming large, and operation in the cabin is prevented. It is possible to prevent the ride comfort of the rider from decreasing as much as possible.

According to a second aspect, in the first aspect, the suspension is configured to be capable of changing a damping force,
By changing the damping force, the state is switched between the suspension working state and the suspension locked state.
Therefore, a suspension lock state can be obtained by setting the damping force to a very large value, and a predetermined suspension characteristic can be obtained by setting the damping force to any other value. As compared with the case where the locked state is obtained, the suspension state can be switched smoothly only by adjusting the damping force, so that the preferable means of claim 1 is obtained.

According to a third aspect of the present invention, in the first aspect, the connection is switchable between a fixed connection state in which the machine frame and the cabin are relatively immovably connected and an allowable state in which the cabin is allowed to move relative to the machine frame. The suspension is switched to the suspension operation state when the means is switched to the permissible state, and the suspension is switched to the suspension locked state when the connecting means is switched to the fixed connection state. Therefore, in the suspension operation state, the machine frame and the cabin are allowed to move relative to each other, so that the suspension operation state can be appropriately secured. In the suspension locked state, the machine frame and the cabin are fixedly connected to each other so as not to be relatively movable. Therefore, it is possible to more reliably obtain the suspension lock state as compared with the case where the suspension lock state is obtained by adjusting the damping force of the suspension, and thus the preferred means of claim 1 is obtained.

According to a fourth aspect, in the third aspect, the contact member supported by the machine frame is moved in the direction approaching the cabin so as to be movable in the approaching / separating direction with respect to the cabin. Is brought into the connection fixed state, and when the contact member is moved in a direction away from the cabin, the state becomes the allowable state. Therefore, the connecting means can be configured with a relatively simple configuration that only moves the contact member that contacts the cabin, and the preferred means of claim 3 is obtained.

According to a fifth aspect, in any one of the first to fourth aspects, the suspension operation state and the suspension lock state are automatically set based on the discrimination information of the traveling state discriminating means for discriminating the traveling state. Switching operation. Therefore, the suspension is automatically switched between the suspension operation state and the suspension lock state according to the traveling state, so that, for example, as compared with the case where the driver manually switches between the suspension operation state and the suspension lock state, Appropriate switching operation can be performed while reducing the driver's operation burden, and the suitable means according to any one of claims 1 to 4 can be obtained.

According to a sixth aspect of the present invention, in the fifth aspect, based on the detection information of the road surface condition detecting sensor for detecting the unevenness state of the traveling surface, the traveling state may be a road traveling state or a work place traveling state. It is determined whether the vehicle is on the road and the operation is switched to the suspension operation state when the vehicle is traveling on a road, and the operation is switched to the suspension lock state when the vehicle is traveling on a work place. Therefore, when the degree of unevenness of the running surface is small, it is determined that the vehicle is traveling on the road, and the state of running is automatically switched to the suspension operation state. The suspension state can be appropriately switched in accordance with the unevenness state of the running surface so that the switching can be appropriately performed, and the preferable means of claim 5 can be obtained.

According to a seventh aspect, in the fifth aspect, an operation state detection is provided for detecting an operation state of an operation target portion which is provided on the vehicle body and is manually operated to be switched between a road traveling state and a work place traveling state. Based on the detection information of the sensor, it is determined whether the traveling state is a road traveling state or a work area traveling state, and if the traveling state is a road traveling state, the operation is switched to the suspension operation state. When there is, the operation is switched to the suspension locked state. Therefore, the driver is automatically switched between the suspension operation state and the suspension lock state according to the operation state of the operation target portion which is manually switched between the road traveling state and the work place traveling state. The driver's operation load can be reduced as compared with the case where the suspension state is manually switched along with the switching operation of the operation target portion. At the same time, the suspension state is determined based on, for example, the detection information of the unevenness state of the running surface. When the state is automatically switched, the operation state can be satisfactorily detected by an inexpensive detection means such as a switch, as compared with the complicated and expensive detection means for the uneven state. Five preferred measures are obtained.

According to an eighth aspect of the present invention, in the active system according to any one of the first to seventh aspects, the suspension automatically adjusts the damping force based on information detected by a traveling condition detecting means for detecting a traveling condition of the vehicle body. The suspension is configured. Therefore, the damping force of the suspension supporting the cabin is automatically adjusted in accordance with the running condition of the vehicle body. For example, in a situation where the vehicle body vibrates greatly, by reducing the damping force, the vibration is minimized to the cabin. By preventing the noise from being transmitted, the riding comfort can be improved, and the noise in the cabin can be reduced. Thus, the preferable means according to any one of claims 1 to 7 can be obtained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a vehicle body having a pair of left and right drivable front wheels 1 and rear wheels 2 is provided with a driving unit having an engine 3 and an engine hood 4 and steering of a steering wheel and the like. The driving cabin 10 is supported by the vehicle body separately from the driving unit, and connects a working device such as a rotary tilling device so as to be able to move up and down. A tractor is provided with a lift arm 5 and a power take-out shaft 6 for transmitting rotational power to a connected working device at a rear portion of the vehicle body.

As shown in FIG. 2, the cabin 10 includes a cabin frame F, a front wall 22, a rear wall 14, and a pair of left and right side doors 1 supported by the cabin frame F.
3, 13, top plate 15, left and right pair of rear wheel fenders 17,
17, bottom plate 16, a pair of left and right steps 16
a, 16a and the like.

First, the cabin frame F will be described. A pair of left and right front pillars 11a, 1 made of an aluminum metal material
Front wall frame 1a, upper front horizontal frame rod 11c made of aluminum metal connecting upper end portions of both front pillars 11a, 11a, and lower front frame 12 connecting lower end portions of both front pillars 11a, 11a. 23. The lower front frame 12 has a horizontal portion connected to the front pillar 11a at both ends and a rod portion 12c formed of an iron pipe bent so as to have a U-shaped portion opened downward between the horizontal portions. And a plate portion 12b made of an iron plate attached to the U-shaped portion of the rod portion 12c so that the air conditioning unit is attached and the inside of the engine hood 4 and the inside of the driving cabin 10 are insulated. is there. A pair of left and right rear pillars 11b, 11b made of an aluminum metal material, and an upper and lower horizontal frame rod 11 made of aluminum metal connecting upper end portions of the both rear pillars 11b, 11b.
d and a lower rear frame rod 11g connecting lower end portions of both rear pillars 11b, 11b.
4 is constituted.

The upper ends of the left front pillar 11a and the rear pillar 11b are connected by an upper left front frame rod 11e facing the front and rear of the aluminum metal cabin, and the right front pillar 1
The upper ends of the front pillar 1a and the rear pillar 11b are connected to each other by an upper right front and rear frame rod 11e facing the front and rear of the aluminum metal cabin, and the lower ends of the left front pillar 11a and the rear pillar 11b face the front and rear of the aluminum metal cabin. The lower right and left front and rear frame rods 11f connect the lower ends of the right front pillar 11a and the rear pillar 11b to each other with the aluminum metal cabin front and rear lower right and rear frame rods 11f. In addition, a pair of left and right iron plate mounting supports 11h, 11h.
Is connected between both ends of the lower rear horizontal frame rod 11g, and a left bottom front and rear frame rod 11j made of an iron pipe facing the cabin front and rear is connected to the lower end of the left mounting support 11h on the rear end side. The front end side is connected to the left end side of the plate portion 12b of the lower front frame 12, and the right bottom front and rear frame rods 11j formed of iron pipes facing the cabin front and rear are connected to the lower end of the right mounting support 11h at the rear end side. The front end is connected to the right end of the plate portion 12b of the lower front frame 12. Further, a left connecting frame rod 11k formed of an iron pipe is provided between the middle portions of the left bottom front and rear frame bars 11j and the lower left front and rear frame bars 11f and between the right bottom front and rear frame bars 11j and the lower right front and rear frame bars 11f. Connected. As described above, each frame rod 11e, 11f, 11
The cabin frame F is constituted by j, 11k, the respective mounting posts 11h, 11h, the front wall frame 23, and the rear wall frame 24.

The front side wall 22 has a transparent upper glass plate portion 22a.
And the upper glass plate portion 22a includes a pair of left and right transparent lower glass plate portions 22b, 22b separated by a dividing line Y.
Edges of the respective glass plate portions 22a and 22b are defined by front pillars 11a,
Plate part 1 of upper front horizontal frame rod 11c and lower front frame 12
2b, the cabin frame F
Is supported by the front wall frame 23.

Each of the pair of side doors 13, 13 is made of a transparent glass plate, and is formed by a pair of upper and lower hinge members 13a, 13a provided on the rear end side.
Is rotatably connected around a vertical axis of the cabin, and is supported by a cabin frame F so that the cabin frame F can be opened and closed by swinging operation around the axis. A cabin entrance / exit formed by 11e, rear pillar 11b, and lower front / rear frame 11f is configured to be opened and closed.

The rear side wall 14 is made of a transparent glass plate, and is connected to the upper rear side frame rod 11d by a pair of left and right hinge members 14a provided on the upper end side so as to be rotatable around the axis of the cabin laterally. The cabin frame F is supported by the rear wall frame 24 so that it can be opened and closed by swinging around the core.

The top plate 15 is made of a synthetic resin plate, and its peripheral edge is connected to each of the upper front horizontal frame rod 11c, the upper rear horizontal frame rod 11d, and a pair of upper front and rear frame rods 11e, 11e to connect to the cabin frame F. It is configured to be supported. Each of the pair of rear wheel fenders 17, 17 is supported by the cabin frame F by being attached to an intermediate portion of the lower front and rear frame 11f and to an attachment support 11h. The bottom plate 16 is supported on the cabin frame F by being mounted on the upper left and right front and rear frames 11j and the right bottom front and rear frames 11j and connected by bolts. Steps 16a and 16a
Is provided.

The driving cabin 10 is mounted on the vehicle body by a suspension type support structure shown in FIGS. That is, as shown in FIG. 1, the left and right bottom front and rear frame rods 11j are connected to a transmission case 8 at an intermediate portion of the vehicle body connected to a rear portion of the clutch housing, and a transmission case 9 at a rear portion of the vehicle body that accommodates traveling and work missions. The driving cabin 10 is disposed so as to be located above and the bottom plate 16 covers above the transmission case 8 and the transmission case 9. A suspension SS is disposed between the L-shaped cabin support member 19a attached to the left and right lateral sides of the transmission case 8 and the cabin 10, and the lower end thereof is pivotally supported by the cabin support member 19a. The upper end is supported by a mounting bracket 18a attached to the bottom plate 16 of the cabin frame F. A cabin support member 19b attached to the lower part of the left and right rear axles 9A extending laterally from the transmission case 9;
Suspension S supporting the cabin 10 between the
S is arranged, and the lower end is pivotally supported by the cabin support member 19b, and the upper end is pivotally supported by the bottom plate of the mounting column 11h of the cabin frame F.

Each of the suspensions SS has the same configuration, and is configured as an active type suspension for automatically adjusting the damping force. Explaining the damping force adjusting mechanism, the suspension SS is provided with a hydraulic cylinder 25 and a coil spring 26 in parallel, and the lower end of a cylinder body 25a of the hydraulic cylinder 25 is connected to each of the support members 19a, 19b on the vehicle body side. 19b, while the upper end of the operation arm 25b is attached to the cabin frame F
11h or mounting bracket 18 on the side
a. When the operation arm 25b is rotated by the aperture adjustment motor 27 installed on the upper portion thereof, the aperture of the rotary valve type variable aperture section ds provided at the piston portion on the distal end side of the operation arm 25b, that is, the operation arm With the expansion and contraction operation of 25b, the size of the throttle with respect to the flow passage for oil that moves in the cylinder main body 25a is changed. Accordingly, the suspension SS includes a damper chamber dc in which the fluid flows in and out as the cabin 10 moves up and down and the volume of the damper chamber changes, a variable throttle portion ds provided in the fluid inflow / outflow passage for the damper chamber dc, An aperture adjusting motor 27 for changing the aperture of the variable aperture section ds is provided, and the damping force is automatically adjusted by changing the aperture of the variable aperture section ds. The coil spring 26 is supported at the upper end by the mounting column 11h or the mounting bracket 18a on the cabin frame F side, and at the lower end by the outer upper end of the cylinder body 25a.

As shown in FIG. 3, between the bottom plate 16 and the transmission case 8, a pair of upper and lower right and left upper and lower parts is provided at the upper center of the transmission case 8 as a mechanism for restricting the lateral movement of the cabin 10 relative to the vehicle body. A shaft portion 8a oriented in the direction is provided, and a shaft portion 16p oriented vertically is provided on both left and right sides on the lower side of the bottom plate 16, and a link 20 is installed between the shaft portions 8a and 16p. I have. And link 2
The cylindrical receiving portions 20a provided on both end sides of the shafts 8a, 16a on the inner surface side are covered with rubber members 21 covered with the shaft portions 8a, 16a.
It is pivoted on p. The link mechanism is provided in a pair at the front and rear of the cabin 10.

Next, a control configuration for the suspension SS will be described. As shown in FIG. 5, a control device 30 is provided using a microcomputer. The control device 30 includes a pair of acceleration sensors S1 for detecting vertical accelerations on both left and right sides of the vehicle body.
A vehicle speed sensor S2 for detecting a vehicle speed, a lift arm sensor S3 for detecting a vertical operation position of the lift arm 5, and an ultrasonic sensor S for detecting a road surface state on the front side.
4 are input. On the other hand, the control device 30
Thus, a drive signal for the aperture adjusting motor 27 is output. Note that the vehicle speed sensor S2 is connected to the wheels 1,
A rotation speed sensor for detecting the rotation speed of the second rotation shaft, a rotation speed sensor for detecting the rotation speed of the drive shaft in the transmission case 9, and the like are used.

Here, the acceleration sensor S1 and the vehicle speed sensor S2 respectively function as running condition detecting means 100 for detecting the running condition of the vehicle body. It is configured to automatically adjust the damping force based on the detection information. Specifically, when the vertical acceleration of the vehicle body detected by the acceleration sensor S1 is large, the control device 30 adjusts the damping force to a small side, that is, the diaphragm of the variable diaphragm ds. The aperture adjusting motor 27 is operated so as to increase the size of the aperture. Here, for example, the average of the magnitudes of the respective detection values of the left and right acceleration sensors S1 is defined as the vertical acceleration of the vehicle body. or,
When the vehicle speed detected by the vehicle speed sensor S2 is high, the diaphragm adjusting motor 27 is adjusted so as to adjust the damping force to a large side, that is, to reduce the size of the diaphragm of the variable diaphragm unit ds. Activate.

Further, the active suspension SS is configured to be freely operable to switch between a suspension operating state and a suspension locked state. Specifically, by changing the damping force that can be changed as described above,
The state is switched between the two suspension states. That is,
When the damping force is set to a very large value, a suspension lock state is established, and for other values of the damping force, a suspension operation state having predetermined suspension characteristics corresponding to each value is obtained.

Then, the control device 30 is used to determine a traveling state determining means 101 for determining a traveling state, and based on the discrimination information of the traveling state determining means 101, the suspension operation state and the suspension locked state are determined. Control means 30 for automatically performing a switching operation is provided. Here, as the traveling state determination means 101,
Although various embodiments can be implemented, two embodiments will be described below as examples. In the first embodiment, the traveling state detecting means 101
Is provided with the ultrasonic sensor S4 as a road surface condition detection sensor for detecting the unevenness state of the running surface, and is configured to determine whether the vehicle is in a road running state or a work place running state. In other words, when the unevenness of the running surface is large, such as a work site that is the soil surface, the amplitude of the reflected wave from the running surface is small, and when the unevenness of the running surface is small, such as on a paved road such as asphalt. Since the amplitude of the reflected wave from the running surface becomes large, it is possible to determine the running state.

In the second embodiment, the traveling state detecting means 101
Is provided on the vehicle body, and includes the lift arm sensor S3 as an operation state detection sensor for detecting an operation state of an operation target portion which is manually switched between a road traveling state and a work place traveling state, It is configured to determine whether the vehicle is in a traveling state or a work place traveling state. That is, in the case of traveling on a work place, the lift arm is operated to lower the working device such as a rotary tilling device as an operation target portion, and in the case of traveling on a road, the lift arm is raised in order to raise the working device. Since the operation is performed, the traveling state can be determined based on the operation state.

The control means 30 is configured to switch to the suspension operation state when the vehicle is traveling on a road, and to switch to the suspension lock state when the vehicle is traveling on a work place.

[Another Embodiment] Another embodiment of the means for adjusting the damping force of the suspension SS will be described with reference to FIG. In this embodiment, the suspension SS is provided with a hydraulic cylinder 31 and a coil spring 26 in a parallel state, and a damper in the hydraulic cylinder 31 whose volume changes due to pressure oil flowing in and out as the cabin 10 moves up and down. Room dc,
A pressure control unit 35 for changing and adjusting the pressure of the pressure oil supplied from the fluid supply source and flowing into and out of the damper chamber dc, so that the damping force is automatically adjusted by adjusting the pressure of the pressure oil. Is configured. More specifically, pressure oil from a hydraulic pump 32 serving as a fluid supply source is opened and closed by a multi-valve 33 to supply pressure oil to a plurality of flow paths to hydraulic cylinders 31 provided on the front, rear, left, and right sides of the vehicle. The passage circulates through the pressure control unit 35 to the damper chamber dc in the hydraulic cylinder 31. An accumulator 34 for reducing pressure fluctuation such as pulsation is connected to an inflow path from the multi-valve 33 to the pressure control unit 35. Although not described in detail, the pressure control unit 35 includes a plurality of valves and an actuator for driving each of the valves.

Then, the control device 30 controls the damper chamber d.
When the pressure control unit 35 is operated so that the pressure of the pressure oil flowing into and out of the damper chamber dc is reduced, the pressure of the pressure oil flowing into and out of the damper chamber dc is increased. When the pressure control unit 35 is operated so as to be as described above, the damping force is adjusted to a large side. In addition, damper room dc
Is connected to a small-capacity sub-accumulator 36. The sub-accumulator 36 absorbs a relatively high-frequency vibration of the vehicle body.

Next, another embodiment of the means for switching the suspension SS to the suspension locked state will be described with reference to FIG. In this embodiment, the connection case in which the transmission case 8 and the transmission case 9 as the machine frame and the cabin 10 are connected so as to be relatively immovable,
A connection means 102 is provided which can be switched to a permissible state in which the relative movement of the cabin 10 with respect to the vehicle is allowed. When the suspension SS is switching the connection means 102 to the permissible state, the suspension SS is switched to the suspension operation state. When the switch 102 is switched to the fixed connection state, the suspension lock state can be switched. More specifically, a pair of contact members 38 which are supported by the machine frames 8 and 9 so as to be movable in the direction of approaching and separating from the cabin 10 (vertical direction in the drawing) and which are disposed at the left and right center sides of the vehicle body. A pair of links 37 and a hydraulic cylinder 39 as operating means for moving the contact member 38 in the direction of approaching and separating from the cabin 10.
Are provided. Here, the lower end of each link 37 is pivotally supported by the machine frames 8 and 9 so as to swing freely, and the upper end of each link 37 is attached with the contact member 38 whose upper surface is covered with a rubber layer. A hydraulic cylinder 39 is provided between the links 37 in the middle, and the hydraulic cylinder 39 is
It operates with pressure oil supplied from a hydraulic control unit 40 that is driven and controlled by the control device 30. The connecting means 102 is connected to the contact member 38 and the operating means (link 37).
And a hydraulic cylinder 39), the contact member 38 being brought into contact with the cabin 10 in the connection and fixed state, and the contact member 38 being separated from the cabin 10 being brought into the allowable state. Have been. That is, when the hydraulic cylinder 39 is contracted, the contact member 38 rises and comes into contact with the cabin 10, and when the hydraulic cylinder 39 is extended, the contact member 38 moves down and separates from the cabin 10.

As the connecting means 102, in addition to the abutting and fixing means, for example, the cabin 10 and the machine frames 8, 9 are hooked and fixed by hook type fixing means. May be something.

In the above embodiment, the coil spring 26 is used as the elastic supporting means provided for the suspension SS. However, other elastic supporting means may be used. For example, as shown in FIG. 6, a leaf spring 28 may be used. When the leaf spring 28 is used, the cabin 10 is supported in a state in which the cabin 10 does not move in the lateral direction with respect to the vehicle body.
It is not necessary to provide a link mechanism (see FIG. 3) for restricting lateral movement of the cabin 10 with respect to the vehicle body.

In the above embodiment, the driving condition detecting means 10
Although the case where the acceleration sensor S1 and the vehicle speed sensor S2 are set to 0 has been described, other sensors and the like may be used as the traveling state detecting means 100.

In the above embodiment, the traveling state detecting means 10
Although the damping force of the suspension SS is automatically adjusted based on the detection information of 0 (the acceleration sensor S1 and the vehicle speed sensor S2), the damping force may be adjusted in another configuration. For example, the ultrasonic sensor S4 detects the unevenness state of the road surface on the front side (that is, when the unevenness of the road surface is large, the amplitude of the reflected wave from the road surface is small, and when the unevenness of the road surface is small, Indicates that the amplitude of the reflected wave from the road surface is large). Based on the detection information of the ultrasonic sensor S4, when the amplitude of the reflected wave from the road surface is large, the damping force of the suspension SS is adjusted to a small side. You may do so.

In the above embodiment, the suspension SS
Although the hydraulic oil has a damping force by a hydraulic mechanism that operates as a fluid, other fluids (such as air) other than oil may be used.

In the above-described embodiment, the cabin 10 and the driving unit such as the engine 3 and the steering unit such as the steering wheel are separately supported by the vehicle body.
The cabin 10 and the driving unit, the control unit, and the like may be integrally connected to each other, and the integrated unit may be supported on the vehicle body by the suspension SS.

In the above embodiment, the work vehicle is configured as a tractor for agricultural work, but may be a work vehicle for various other uses.

[Brief description of the drawings]

Fig. 1 Side view of the entire tractor

FIG. 2 is a perspective view of the driving cabin in an exploded state.

FIG. 3 is a front view showing a support structure for a front portion of a driving cabin.

FIG. 4 is a front view showing a support structure at a rear portion of the cabin for driving.

FIG. 5 is a block diagram of control.

FIG. 6 is a side view showing a main part of a suspension according to another embodiment.

FIG. 7 is an explanatory diagram showing a damping force adjustment configuration according to another embodiment.

FIG. 8 is an explanatory view showing a connecting means according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cabin 30 Control means 8, 9 Machine frame 38 Contact member 37, 39 Operating means 100 Running state detecting means 101 Running state discriminating means 102 Connecting means S3 Operating state detecting sensor S4 Road surface state detecting sensor SS Suspension

Claims (8)

[Claims] 1. A suspension for supporting a cabin,
A work vehicle configured to be freely switchable between a suspension operation state and a suspension lock state. 2. The work according to claim 1, wherein the suspension is configured to be capable of changing a damping force, and is configured to switch between the suspension operation state and the suspension locked state by changing the damping force. vehicle. 3. A connection means which is switchable between a fixed connection state in which the machine frame and the cabin are connected so as to be relatively immovable and an allowance state in which the cabin is allowed to move relative to the machine frame, wherein the suspension is provided. The switching means is switched to the suspension operation state when the connection means is switched to the allowable state, and the suspension means is switched to the suspension lock state when the connection means is switched to the connection fixed state. The working vehicle according to claim 1. 4. An abutment member supported by the machine frame so as to be movable in an approaching / separating direction with respect to the cabin, and operating means for operating the abutting member in an approaching / separating direction with respect to the cabin. The connection means is configured to include the contact member and the operating means, and the connection member is brought into the connection fixed state by contact with the cabin, and the contact member is moved from the cabin. The work vehicle according to claim 3, wherein the work vehicle is configured to be in the allowable state when separated. 5. A running state determining means for determining a running state, and a control means for automatically switching between the suspension operating state and the suspension locked state based on the determination information of the running state determining means. The work vehicle according to any one of claims 1 to 4, wherein the work vehicle is provided. 6. The running state detecting means includes a road surface state detecting sensor that detects an uneven state of a running surface, and is configured to determine whether the vehicle is in a road running state or a work place running state. 6. The work vehicle according to claim 5, wherein the control means is configured to switch the suspension operation state when the vehicle is traveling on a road and the suspension lock state when the vehicle is traveling on a work place. 7. An operation state detection sensor provided on a vehicle body, wherein the operation state detection means detects an operation state of an operation target portion that is manually switched between a road traveling state and a work place traveling state. The control means is configured to determine whether the vehicle is traveling on a road or a traveling road, and the control unit is configured to operate the suspension when the vehicle is traveling on the road, and to operate the suspension lock when the vehicle is traveling on a working road. The work vehicle according to claim 5, wherein the work vehicle is configured to be switched to a state. 8. The suspension according to claim 1, wherein the suspension is configured as an active suspension that automatically adjusts a damping force based on detection information of a traveling state detecting unit that detects a traveling state of a vehicle body. The work vehicle according to claim 1.