JPH07315112A - Vehicle with working machine - Google Patents

Abstract

PURPOSE:To improve the working efficiency and working accuracy of a working machine. CONSTITUTION:A front shaft 8 is supported on the front part of a car body 3 swingably in vertical direction around a pivot part 9 and a working machine 2 for moving is installed turnably in a horizontal direction on the front part of the car body 3. The upper part of the cylinder tube 30 of a double acting hydraulic cylinder 27 is connected to the front part of the car body 3 and the front shaft 8 is connected to the lower part of the piston rod 32 of the hydraulic cylinder 27. When a working machine 2 is turned left, a hydraulic changeover valve 28 is switched from a neutral position Z to an extend operation position X by interlocking to this turning and a pressurized oil is supplied to the operation room 35 for extending operation and it is obstructed that the car body 3 is inclined to the left side in relation to the front shaft 8. When the working machine 2 is turned to the right side, the hydraulic changeover valve 28 is switched from its neutral position Z to a shrink operation position Y by interlocking to this turning and the pressurized oil is supplied to the operation room 34 for shrinking and it is obstructed that the car body 3 is inclined to the right side in relation to the front shaft 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working vehicle provided with a working machine such as a mower.

[0002]

2. Description of the Related Art In a tractor which is a work vehicle of this type, a rear axle is fixedly mounted on a rear portion of a vehicle body 103 and a front portion of the vehicle body 103 is mounted on the rear portion of the vehicle body 103, as shown in a schematic front view of FIG. There is one in which a front axle 108 is supported so as to be swingable in the vertical direction around a pivot 109.

[0003]

In the conventional tractor described above, the following problems occur when the working machine 102 such as a mower is mounted on the front portion of the vehicle body 103 so as to be horizontally rotatable. As shown in the drawing, when the working machine 102 is turned to the left in a front view, the eccentric load F of the working machine 102 causes the pivot portion 1 to move.
Since a counterclockwise moment is generated around 09, the vehicle body 103 leans greatly to the left. Similarly, when the working machine 102 is turned to the right when viewed from the front, the vehicle body 103 is greatly tilted to the right.

The sense of instability due to the large inclination of the vehicle body 103 impedes the operator's concentration, so that the work efficiency is lowered. Further, as the vehicle body 103 is greatly tilted, the work machine 102 attached to the vehicle body 103 is also greatly tilted, so that the working accuracy is reduced. Further, since the front portion of the vehicle body 103 is tilted to the left and right, the front portion of the vehicle body 103 is twisted with respect to the rear portion, so that the life of the vehicle body 103 is reduced.

On the other hand, when the working machine is attached to the rear portion of the vehicle body, since the rear axle is fixedly provided at the rear portion of the vehicle body,
Although the above problem can be solved by preventing the tilting of the vehicle body due to the eccentric load of the work machine, the following problem newly arises. That is,
When working in forward traveling, it is necessary for the operator to check not only the front but also the rear of the working machine side. Therefore, the burden on the operator is large and the work efficiency is reduced.

An object of the present invention is to eliminate the above-mentioned various problems and improve work efficiency and work accuracy.

[0007]

In order to achieve the above-mentioned object, the present invention has a working machine-equipped vehicle as follows.

(Invention of Claim 1) For example, as shown in FIGS. 1 to 9, a rear axle 7 is fixed to the rear portion of the vehicle body 3 and a front axle 8 is vertically attached to the front portion of the vehicle body 3 above. In a vehicle equipped with a working machine, which is swingably supported and has the working machine 2 mounted on the vehicle body 3 so as to be horizontally rotatable, the working machine 2 is mounted on the front portion of the vehicle body 3, and A connecting means A for switching between the front portion of the vehicle and the front axle 8 in at least two states, a connected state that prevents relative swinging of the two and a released state that allows relative swinging of the same. And the connecting means A is at least 2 above.
The operation means B for switching between the two states is provided.

The connecting means A is connected to the hydraulic cylinder 2
In the case of the configuration of No. 7, a hydraulic switching valve 28 that supplies and discharges pressure oil to and from the hydraulic cylinder 27 can be considered as the operating means B. Further, when the connecting means A is constituted by a fixed rod or the like, the operating means B is an electric motor or solenoid for connecting and disconnecting the fixed rod to the vehicle body 3 or the front axle 8. Conceivable.

(Invention of Claim 2) In the structure of Claim 1 described above, the following structure is added, for example, as shown in FIGS. 1 to 9 above. The connecting means A is constituted by a double-acting hydraulic cylinder 27, and the operating means B is constituted by a hydraulic switching valve 28, and the cylinder tube 30 and the piston rod 3 of the hydraulic cylinder 27 are constituted.
One of the two 30 is connected to the front part of the vehicle body 3 and the other 32 is connected to the front axle 8 to connect the two working chambers 34 and 35 of the hydraulic cylinder 27 to the hydraulic switching valve. By 28, the pressure port P and the discharge port T can be selectively connected.

(Invention of Claim 3) In addition to the structure of claim 1, the following structure is added, for example, as shown in FIG. The connecting means A is constituted by left and right single-acting hydraulic cylinders 70, 70, and the operating means B is constituted by a hydraulic switching valve, and among the cylinder tubes 71 and the piston rods 72 of the hydraulic cylinders 70 described above. One side 71 is connected to the front part of the vehicle body 3 and the other side 72 is connected to the front axle 8, and the working chamber 73 of the hydraulic cylinder 70 is connected to the pressure port and the discharge port by the hydraulic pressure switching valves. It is configured to be selectively connectable.

(Invention of Claim 4) In the structure of claim 2 or 3, for example, as shown mainly in FIG. 9 in FIGS. 1 to 9, the working hydraulic cylinder of the working machine 2 is used. The load-side working chamber 19a of 19 is connected to the pressure port P.

[0013]

[Action]

(Invention of Claim 1) For example, as shown in FIG. 1, it operates as follows. During normal traveling of the work vehicle 1, the work machine 2 is housed in the center portion of the vehicle body 3 in the left-right direction, and the coupling means A is switched to the uncoupled state. In this disconnected state, the front portion of the vehicle body 3 can be swung up and down around the pivotal support portion 9 with respect to the front axle 8 in the same manner as in the conventional example shown in FIG.

As shown in the drawing, when the working machine 2 is turned to the left, the connecting means A is switched to the connected state prior to or almost at the same time, so that the vehicle body 3 with respect to the front axle 8 is turned on.
Prevent the front part of the rock from swinging. In this rocking prevention state, a counterclockwise moment is generated around the pivot portion 9 due to the eccentric load F of the working machine 2 described above, but against this, the reaction force R of the road surface G causes the left front wheel 4 to move. Then, a clockwise moment is generated around the pivot 9 through the front axle 8, the connecting means A and the vehicle body 3 in this order. By balancing these moments, it is possible to prevent the vehicle body 3 from tilting with respect to the front axle 8.

(Invention of Claim 2) For example, as shown in the above-mentioned FIG. 1, it operates as follows. During normal traveling of the work vehicle 1, the hydraulic pressure switching valve 28 is switched to the neutral position Z, and the cylinder tube 30 and the piston rod 32 of the double-acting hydraulic cylinder 27 are relatively movable in the vertical direction. In this uncoupled state, the front part of the vehicle body 3 can be swung up and down around the pivotal part 9 with respect to the front axle 8.

As shown in the drawing, when the working machine 2 is turned to the left, the hydraulic switching valve 28 is switched to the extension operation position X prior to or almost at the same time. Then, the cylinder tube 30 of the hydraulic cylinder 27 and the piston rod 32 are relatively extended to prevent the vehicle body 3 from leaning leftward with respect to the front axle 8. On the contrary to the above, when the working machine 2 is turned to the right, the hydraulic switching valve 28 is switched to the contraction operation position Y. Then, the cylinder tube 30 of the hydraulic cylinder 27 and the piston rod 32 are relatively contracted to prevent the vehicle body 3 from leaning to the right with respect to the front axle 8.

(Invention of Claim 3) For example, as shown in FIG. 10 described above, it operates as follows. During normal traveling of the work vehicle 1, the cylinder tubes 71 and the piston rods 72 of the left and right hydraulic cylinders 70 are vertically movable relative to each other, and the front portion of the vehicle body 3 rotates around the pivot portion 9 with respect to the front axle 8. It is possible to swing vertically.

As shown in the drawing, when the working machine 2 is turned to the left, the cylinder tube 71 and the piston rod 72 of the left hydraulic cylinder 70 are relatively extended prior to or substantially at the same time. The vehicle body 3 is prevented from leaning to the left with respect to the front axle 8. On the contrary, when the working machine 2 is turned to the right, the right cylinder tube 71 and the piston rod 72 are relatively extended to prevent the vehicle body 3 from leaning to the right with respect to the front axle 8. Block.

(Invention of Claim 4) For example, as shown in FIG. 1 and FIG. 9, it operates as follows. Since the load side working chamber 19a of the working hydraulic cylinder 19 is connected to the pressure port P of the hydraulic cylinder type connecting means A, the load side working chamber 1
The high hydraulic pressure generated at 9a can be quickly supplied to the hydraulic working chamber 34 or 35 of the above-mentioned connecting means A.
Can be operated smoothly. Even if the engine of the work vehicle is stalled, the connecting means A can be held in the connected state by the holding force due to the residual pressure of the load-side working chamber 19a of the working hydraulic cylinder 19, so that even in this case. Inclination of the vehicle body 3 can be prevented.

[0020]

The present invention has the following effects because it is configured and operates as described above. (Invention of Claim 1) Since the vehicle body can be prevented from tilting left and right even when the working machine is turned to the left and right, the sense of instability due to the tilting of the vehicle body can be eliminated and the operator can concentrate on the work, thus improving work efficiency. To do. Further, by preventing the vehicle body from leaning, it is possible to prevent the working machine attached to the vehicle body from leaning, so that the working accuracy is improved. Furthermore, by preventing the front portion of the vehicle body from leaning to the left and right, twisting of the front portion of the vehicle body can be suppressed, so that the life of the vehicle body is extended. Moreover, since the working machine is provided in the front part of the vehicle body, it is not necessary for the operator to check the rear side while working in forward traveling, the burden on the operator is reduced, and the work efficiency is improved also from this point.

(Invention of Claim 2) Since the connecting means is constituted by the hydraulic cylinder, the relative swing between the vehicle body and the front axle can be strongly prevented, so that the leaning of the vehicle body during work can be reliably prevented. Further, by constructing the connecting means by one double-acting hydraulic cylinder, the structure for attaching the connecting means can be simplified, and the pressure oil supply / discharge circuit of the hydraulic connecting means can be simplified.

(Invention of Claim 3) Similar to the invention of Claim 2 described above, by constructing the connecting means by a hydraulic cylinder, the relative swing between the vehicle body and the front axle can be strongly prevented, and therefore, during the work. The leaning of the vehicle body can be reliably prevented.

(Invention of Claim 4) Since the high hydraulic pressure generated in the load side working chamber of the working hydraulic cylinder can be quickly transmitted to the hydraulic cylinder type connecting means, the connecting means can be operated smoothly. Is.

[0024]

【Example】

(First Embodiment) FIGS. 1 to 9 show a first embodiment. First, the overall configuration of the vehicle with a working machine will be described with reference to FIGS. 2 to 4. FIG. 2 is a side view of the tractor 1 which is a vehicle. FIG. 3 is a partial side view of the working machine 2 attached to the tractor 1. FIG. 4 is a front view of the tractor 1 to which the working machine 2 is attached. In FIG. 2, reference numeral 3 is a vehicle body of the tractor 1, reference numeral 4 is a front wheel, and reference numeral 5 is a rear wheel. A rear axle 7 is fixed to the rear portion of the vehicle body 3 described above. A front axle 8 is supported on the front portion of the vehicle body 3 of the above so as to be swingable within a predetermined range in the vertical direction about a pivot portion 9. Reference numeral 10 is a cabin.

The working machine 2 is attached to the vehicle body 3 so as to be horizontally rotatable. That is, the mounting frame 11 is fixed to the front part of the vehicle body 3, and the base frame 13 of the working machine 2 is detachably supported by the hook 12 provided in the front part of the mounting frame 11. Bracket 14 on the above-mentioned base frame 13
Is supported by the pivot pin 15 so as to be rotatable in the horizontal direction.

The first lift arm 18 supported by the bracket 14 is swung by the first working hydraulic cylinder 19. The second arm 20 supported by the first arm 18 is swung by the second working hydraulic cylinder 21. The bracket 22 supported by the second arm 20 is swung by the third working hydraulic cylinder 23. A mower 24, which is an attachment, is detachably fixed to the bracket 22. The mower 24 is driven by a hydraulic motor 25 (not shown here) which will be described later.

Both the mounting frame 11 and the front axle 8 are connected by a hydraulic cylinder 27 for suspension, which is a connecting means A, so that they cannot be relatively swung. This suspension hydraulic cylinder 27 has a connection state in which a relative switching of the both 11 and 8 is prevented by an oil pressure switching valve 28 (not shown here) which is an operating means B described later, and a state in which both the above 11 and 11 are connected. 8 is switched to a disconnection state in which relative swinging of 8 is permitted.

The suspension hydraulic cylinder 27
Are configured as shown in the vertical sectional view of FIG. That is, the piston 31 is inserted into the cylinder tube 30 so as to be vertically oiltightly slidable. A piston rod 32 projects downward from the piston 31, and a guide rod 33 projects upward from the piston 31. A contraction working chamber 34 is formed below the piston 31, and an extension working chamber 35 is formed above the piston 31. Then, as shown in FIG. 4, the cylinder tube 3
The upper part of 0 is swingably connected to the mounting frame 11, and the lower part of the piston rod 32 is swingably connected to the front axle 8.

Next, the structure for turning the bracket 14 of the working machine 2 will be described with reference to FIGS. 3, 6 and 7. FIG. 6 is a sectional view taken along the line VI-VI in FIG. FIG. 7 is a view taken along the line VII-VII in FIG. 3 above. A hydraulic cylinder 37 for turning is attached to the base frame 13.
Is attached. The turning hydraulic cylinder 37 is of a double-acting type, and both ends of the piston rod 38 are fixed to the base frame 13, and the piston rod 3 is
The rack 40 is fixed to the cylinder tube 39 which is reciprocated along the line 8. By reciprocating the rack 40, the pinion 41 fixed to the bracket 14 is rotated, and the bracket 14 and the lift first arm 18 supported by the bracket 14 are swung.

The hydraulic pressure switching valve 28 is the same as the base frame 1 described above.
3 and is switched by a cam groove 43 fixed to the cylinder tube 39. That is, as shown in the elevation view of FIG. 8, an intermediate part of the arm 47 is swingably supported by the valve box 45 of the switching valve 28 via the support plate 46. Spool 48 on the left side of the arm 47
The lower part of the roller 4 is connected to the right end of the arm 47 of the same.
9 is supported. The reciprocating movement of the cylinder tube 39 causes the roller 49 to move in the vertical direction by the cam groove 43 (see FIG. 7), which causes the spool 48 to switch in the vertical direction.

The operation of the tractor with a working machine will be described with reference to FIGS. 4 and 1 and 9. Figure 1
It is a front view schematic diagram of a tractor. FIG. 9 is a hydraulic circuit diagram of the work machine 2. The two hydraulic pumps 52 and 53 are driven by the power take-off shaft 51 (see FIG. 9) provided on the tractor 1. One of the hydraulic pumps 52 can drive the lawn mower hydraulic motor 25. Reference numeral 54 is an operation control valve for the hydraulic motor. The other hydraulic pump 53
Thus, the first working hydraulic cylinder 19, the second working hydraulic cylinder 21, the third working hydraulic cylinder 23, the turning hydraulic cylinder 37, and the suspension hydraulic cylinder 27 are driven.

In the first working hydraulic cylinder 19, the extension working chamber 19a is constructed as a load side working chamber. That is, due to the load acting on the first arm 18, a larger load is exerted when the hydraulic cylinder 19 is extended than when it is contracted. Reference numeral 19b is a working chamber for contraction. On the contrary, in the second and third working hydraulic cylinders 21 and 23, the contraction working chambers 21b and 23b are respectively configured as load side working chambers. These load-side working chambers are defined by the above-mentioned first hydraulic cylinder 19
Is the same as. Reference numerals 21a and 23a respectively denote extension working chambers. The above-mentioned first to third hydraulic cylinders 19
The 21 and 23 are expanded and contracted by the first to third operation control valves 56, 57 and 58, respectively.

The cylinder tube 39 of the turning hydraulic cylinder 37 is reciprocated by a turning operation control valve 59. 2 of the hydraulic cylinder 27 for suspension
One of the working chambers 34 and 35 can be selectively connected to the pressure port P and the discharge port T by the hydraulic pressure switching valve 28.
The extension working chamber 19a, which is the load-side working chamber of the first hydraulic cylinder 19, is connected to the pressure port P via the communication passage 62.
Connected to.

When the cylinder tube 39 is moved to the left side in FIG. 9 by the turning operation control valve 59, the working machine 2 is turned to the left side in front view as shown in FIG. 1 or 4. At the same time, the hydraulic pressure switching valve 28 is switched to the extension operation position X. This prevents the suspension hydraulic cylinder 27 from extending and preventing the vehicle body 3 from leaning leftward with respect to the front axle 8.

On the contrary, the above-mentioned turning operation control valve 5
When the cylinder tube 39 of the above is moved to the right side in FIG. 9 by 9, the working machine 2 is turned to the right side in front view, and the hydraulic switching valve 28 is switched to the contraction operation position Y. As a result, the suspension hydraulic cylinder 27 is prevented from contracting to prevent the vehicle body 3 from leaning to the right with respect to the front axle 8.

Further, when the cylinder tube 39 is operated to the center portion in the left-right direction by the turning operation control valve 59, the hydraulic switching valve 28 is held at the neutral position Z, and the suspension hydraulic cylinder 27 is free. Becomes the disconnected state.

In the first embodiment described above, since the working machine 2 is provided in the front part of the vehicle body 3, it is not necessary for the operator to check the rear side during the forward traveling, and the working efficiency is improved. In addition, the first embodiment can prevent the vehicle body 3 from tilting even when the working machine 2 turns to the left and right, so that the following advantages can be obtained. The instability due to the tilt of the vehicle body is eliminated, and the operator can work with peace of mind, thus improving work efficiency. Further, by preventing the vehicle body 3 from tilting, it is possible to prevent the working machine 2 attached to the vehicle body 3 from tilting, so that the working accuracy is improved. Furthermore, by preventing the front portion of the vehicle body 3 from leaning to the left and right, twisting of the front portion of the vehicle body 3 can be prevented, so that the life of the vehicle body 3 is extended.

When the tractor 1 is traveling normally and the work implement 2 is housed in the center of the vehicle body 3 in the left-right direction, the hydraulic switching valve 28 is automatically switched to the neutral position Z, and the suspension hydraulic cylinder 27 is moved. Since the connection is maintained in the disconnected state, stable driving can be obtained as with a normal tractor. On the other hand, when the working machine 2 is turned to the left and right during the work, the hydraulic pressure switching valve 28 is automatically switched in conjunction with this, and the suspension hydraulic cylinder 27 is switched to the connected state, so that the vehicle body 3 tilts. Can be prevented automatically. In this way, since the turning operation of the work implement 2 and the switching operation of the hydraulic pressure switching valve 28 are interlocked with each other, it is not necessary for the operator to switch the hydraulic pressure switching valve 28, and the burden on the operator during work can be reduced.

Since the pressure port P of the hydraulic pressure switching valve 28 is connected to the extension working chamber 19a which is the load side working chamber of the first working hydraulic cylinder 19, it is generated in the first working hydraulic cylinder 19. A high hydraulic pressure can be quickly supplied to the suspension hydraulic cylinder 27.
It is possible to operate 7 smoothly. Even if the engine of the tractor 1 stalls,
Since the suspension hydraulic cylinder 27 can be held in the connected state by the holding force due to the residual pressure of the expansion working chamber 19a of the first hydraulic cylinder 19, the vehicle body 3 can be maintained even in this case.
Can be prevented from tilting.

Further, as shown in FIG. 1, when the front wheel 4 on the left side gets over an obstacle or the like during traveling work in a state in which the working machine 2 is turned to the left side, the hydraulic cylinder 27 which is being extended is greatly moved. The impact force acts to generate an excessive hydraulic pressure in the extension working chamber 35. Then, the excessive hydraulic pressure passes through the communication passage 62 and the first hydraulic cylinder 19 described above.
By being escaped to, the impact from the obstacle can be buffered. It should be noted that a large impact is applied to the front wheel 4 on the right side while the working machine 2 in the above is turned to the left side, or the working machine 2
Even when a large impact is applied to either the left or right front wheel 4 in a state where the vehicle is turned to the right, the impact can be buffered similarly to the above.

In the first embodiment described above, instead of providing the communication passage 62 in FIG. 9, the second working work is used.
Contraction working chamber 21b which is the load side working chamber of the cylinder 21
May be communicated with the pressure port P through another communication passage 63 (see the two-dot chain line in FIG. 9 above).

10 and 11 show a second embodiment and a third embodiment, respectively, and are schematic views corresponding to FIG. 1 described above. In these other embodiments, members having the same configurations as those of the first embodiment will be described by attaching the same reference symbols in principle.

(Second Embodiment) As shown in FIG. 10, the connecting means A is composed of two hydraulic cylinders 70 for suspension on the left and right, and each hydraulic cylinder 70 of a single-acting type is hydraulically operated. The extension operation is performed by a switching valve (not shown). The hydraulic pressure switching valve is constructed in substantially the same manner as that of the first embodiment. The upper part of the cylinder tube 71 of each hydraulic cylinder 70 is swingably connected to the front part of the vehicle body 3, and the lower part of the piston rod 72 is swingably connected to the front axle 8. The expansion working chamber 73 of the hydraulic cylinder 70 is configured to be selectively connectable to a pressure port and a discharge port (neither is shown) by the hydraulic pressure switching valve.

This second embodiment operates as follows. When the working machine 2 is swung to the left in a front view as shown in the drawing, pressure oil is supplied to the extension working chamber 73 of the left hydraulic cylinder 70, which prevents the vehicle body 3 from leaning to the left. . On the contrary, when the working machine 2 is swung to the right in the front view, pressure oil is supplied to the extension working chamber 73 of the right hydraulic cylinder 70, which prevents the vehicle body 3 from leaning to the right. To be done.

The above second embodiment can be modified as follows. That is, the hydraulic cylinder is configured to be contracted by the supply of pressure oil, and when the working machine 2 is swung to the left side in front view, the hydraulic cylinder on the right side is contracted, whereas the working machine 2 is viewed in front view. The hydraulic cylinder on the left side is configured to contract when it is turned to the right side. The single-acting hydraulic cylinder may be of a spring return type.

(Third Embodiment) As shown in FIG.
An inclination sensor 76 is attached to the vehicle, and when the vehicle body 3 is inclined in the left-right direction, the electromagnetic hydraulic switching valve 28 is switched via the controller 77. Car body 3
The suspension hydraulic cylinder 27 provided between the front part and the front axle 8 is of a double-acting type, as in the first embodiment.

The above-mentioned third embodiment has the following advantages.
When horizontally controlling a three-point link mechanism or the like provided at the rear of the tractor 1, the suspension hydraulic circuit and the electric circuit according to the present invention can be used as the main parts of the hydraulic circuit and the electric circuit for the control. The device is simple.

The third embodiment described above can be modified as follows. Instead of providing the inclination sensor 76, a position sensor that detects the turning state of the work machine 2 is provided, and the electromagnetic hydraulic switching valve 28 is switched based on the detection signal of the position sensor.

Each of the above embodiments can be modified as follows. The connecting means A may be of any type as long as it can switch between a state in which the relative swing between the vehicle body 3 and the front axle 8 is blocked and a state in which the relative swing is allowed. Instead, it may be a fixing member such as a fixing rod / turnbuckle or a flexible member such as a wire / chain. In this case, as the operating means B, an electric motor, a solenoid or the like for connecting / disconnecting the fixed member or the flexible member to / from the vehicle body 3 or the front axle 8 can be considered. Further, the connecting means A may have a semi-connected state between the connected state and the disconnected state.

The working machine 2 may be directly supported by the vehicle body 3 instead of being supported by the mounting frame 11. The attachment to be attached to the working machine 2 is
Instead of a mower, another type of device such as a digger may be used. The working vehicle 1 is not limited to the tractor, and may be a construction vehicle or the like.

[Brief description of drawings]

FIG. 1 is a schematic front view of a work vehicle showing a first embodiment of the present invention.

FIG. 2 is a side view of the vehicle.

FIG. 3 is a partial side view of a work machine attached to the vehicle.

FIG. 4 is a front view of a vehicle to which the working machine described above is attached.

FIG. 5 is a vertical sectional view of a double-acting hydraulic cylinder attached to the vehicle.

6 is a sectional view taken along the line VI-VI in FIG. 3 described above.

FIG. 7 is a view taken along the line VII-VII in FIG. 3 above.

FIG. 8 is an elevational view of a hydraulic pressure switching valve provided in the working machine.

FIG. 9 is a hydraulic circuit diagram of the working machine.

FIG. 10 is a view showing a second embodiment of the present invention and corresponding to FIG. 1 described above.

FIG. 11 is a view showing a third embodiment of the present invention and corresponding to FIG. 1 described above.

FIG. 12 is a diagram corresponding to FIG. 1 described above, showing a conventional example.

[Explanation of symbols]

2 ... Working machine, 3 ... Car body, 7 ... Rear axle, 8 ... Front axle, 19
... Work hydraulic cylinder (work first hydraulic cylinder), 19
a ... load side working chamber (extending working chamber), 27 ... double-acting hydraulic cylinder (suspension hydraulic cylinder), 28 ... hydraulic switching valve, 30 ... cylinder tube, 32 ... piston rod, 34 ... contracting working chamber, 35 ... Working room for extension, 70 ...
Single-acting hydraulic cylinder (hydraulic cylinder for suspension),
71 ... Cylinder tube, 72 ... Piston rod, 73
... working chamber, A ... connecting means, B ... operating means, P ... pressure port,
T ... outlet.

Claims (4)

[Claims] 1. A rear axle (7) is fixed to a rear portion of the vehicle body (3), and a front axle (8) is swingably supported in a vertical direction on a front portion of the vehicle body (3). In a vehicle with a working machine in which the working machine (2) is attached to the vehicle body (3) so as to be horizontally rotatable, the working machine (2) is attached to the front part of the vehicle body (3),
Between the front part of the vehicle body (3) and the front axle (8),
There is provided a connecting means (A) which can be switched to at least two states of a connected state for preventing relative swinging of these two and a disconnected state for permitting relative swing of the same, and the connecting means is provided.
Operation means for switching (A) to at least the above two states
(B) is provided and comprised, The vehicle with a working machine characterized by the above-mentioned. 2. A vehicle with a working machine according to claim 1, wherein the connecting means (A) is constituted by a double-acting hydraulic cylinder (27), and the operating means (B) is a hydraulic switching valve.
(28), one (30) of the cylinder tube (30) and the piston rod (32) of the hydraulic cylinder (27) is connected to the front part of the vehicle body (3) and the other (32) is connected. ) Is connected to the front axle (8), and the two working chambers (34) (35) of the hydraulic cylinder (27) are connected to the pressure port (P) and the discharge port by the hydraulic switching valve (28). A vehicle with a working machine configured to be selectively connectable to (T). 3. The vehicle with work implement according to claim 1, wherein the connecting means (A) is provided on the left and right single-acting hydraulic cylinders (70).
(70) and the operating means (B) is a hydraulic switching valve, and each of the above hydraulic cylinders (70)
One of the cylinder tube (71) and the piston rod (72) (71) is connected to the front part of the vehicle body (3) and the other (72) is connected to the front axle (8). A working machine-equipped vehicle in which the working chamber (73) of the hydraulic cylinder (70) is selectively connectable to the pressure port and the discharge port by the above-mentioned hydraulic switching valves. 4. The vehicle with work implement according to claim 2 or 3, wherein the load side working chamber (19a) of the working hydraulic cylinder (19) of the work implement (2) is connected to the pressure port (P). A vehicle with a work implement configured by connecting to.