JPH07132803A - Auxiliary steering device of vehicle - Google Patents

Abstract

PURPOSE:To reduce elevation stroke, and to make a device compact by supporting an auxiliary wheel on a car body through the suspension of a vehicle. CONSTITUTION:Right and left auxiliary front wheels 16, 17 and auxiliary rear wheels 18, 19 are provided on a vehicle 11, and the axles of the wheels are arranged perpendicular to the axles of front wheels 12, 13 and the rear wheels 14, 15. A hydraulic cylinder 21 is provided with a drive rod 39, and an auxiliary front wheel, for example, corresponding to the front wheel is mounted on the front end part of the rod. The hydraulic cylinder 21 is mounted on a suspension 35 through a mounting bracket 40, and when oil pressure is fed, the drive rod 39 is actuated, while the auxiliary front wheel 16 is lowered so as to lift the vehicle. Since the auxiliary wheels 16-19 are fitted to the suspension 35 of the vehicle, the strokes of the hydraulic cylinders 21-24 can be limited to a small level when the auxiliary wheels are lowered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary steering device for a vehicle, which is provided with auxiliary wheels on a vehicle body so that the vehicle can be moved laterally in order to perform parallel parking of the vehicle in a narrow space.

[0002]

2. Description of the Related Art Recently, in order to park a vehicle in parallel in a narrow space, auxiliary wheels are provided in front of and behind the vehicle in addition to steering wheels and drive wheels. It is considered that the vehicle can be moved laterally by lifting and driving auxiliary wheels in this state. As such a drive control device for an auxiliary wheel, there has been heretofore known JP-A-4-9555.
There is one disclosed in Japanese Patent Laid-Open No. 2.

In the device disclosed in this publication, an auxiliary wheel which can be driven and rotated is attached to the rear part of a vehicle body through a support arm, and the auxiliary wheel can be moved up and down by a hydraulic jack mechanism, and a hydraulic motor is attached to the auxiliary wheel. It is mounted, and the hydraulic jack mechanism and the hydraulic motor are connected to the hydraulic pump of the power steering through the first oil passage and the second oil passage. Then, hydraulic pressure is supplied from the hydraulic pump to the hydraulic jack mechanism via the first oil passage, and the auxiliary wheels are lowered to lift the vehicle. In this state, hydraulic pressure is applied from the hydraulic pump to the hydraulic motor via the second oil passage. When supplied and the auxiliary wheels are driven, the vehicle can move laterally.

[0004]

In the above-mentioned conventional auxiliary wheel steering device, the auxiliary wheel is attached to the rear part of the vehicle body through the support arm, and the auxiliary wheel is rotated by the hydraulic jack mechanism. Is grounded on the road surface and the vehicle body is lifted to separate the rear wheels from the road surface. In this state, the hydraulic motor is operated to rotationally drive the auxiliary wheels. However, in general, the wheels are supported by the vehicle body via suspensions, coil springs, etc., and when the vehicle body is lifted, the coil springs stretch and the suspension strokes, causing the wheels to lower relative to the body. Therefore, this wheel cannot be lifted from the road surface unless the vehicle body is lifted to some extent in consideration of the amount. Therefore, in the above-described conventional auxiliary wheel steering device, it is necessary to secure a sufficient length of the support arm and set a large operation stroke of the hydraulic jack mechanism, which causes a problem that the device becomes large. there were.

The present invention solves such a problem, and an object of the present invention is to provide an auxiliary wheel steering device in which the device is made compact.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, an auxiliary steering apparatus of the present invention is provided with an auxiliary wheel at a lower portion of a vehicle body, the auxiliary wheel being supported by an elevating mechanism so as to be able to move up and down, and a drive motor. In the auxiliary steering device for a vehicle rotatably supported by the vehicle, the auxiliary wheels are supported by the vehicle body via a suspension of the vehicle.

[0007]

Since the auxiliary wheels are supported by the vehicle body through the suspension of the vehicle, when the vehicle body is lifted by the elevating mechanism, the vehicle body ascends together with the suspension, so that the elevating mechanism requires less vertical stroke. Also,
The lifted vehicle body is supported by the auxiliary wheels on the road surface through the elevating mechanism and the suspension, and even when the vehicle is driven by the auxiliary wheels, the suspension acts in the same manner as usual and the riding comfort is not impaired.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 shows a schematic structure of an auxiliary steering apparatus according to an embodiment of the present invention, FIG. 2 shows a schematic of a vehicle equipped with the auxiliary steering apparatus of this embodiment, and FIG. 3 shows a mounting state of the auxiliary steering apparatus. .

In the auxiliary steering system of this embodiment, as shown in FIG. 2, a vehicle 11 includes left and right front wheels 12, 13 and rear wheels 14, 15 and left and right auxiliary front wheels 16, 1
7 and auxiliary rear wheels 18 and 19. The axles of the auxiliary wheels 16, 17, 18 and 19 are arranged substantially orthogonal to the axles of the front wheels 12 and 13 and the rear wheels 14 and 15. The auxiliary wheels 16, 17, 18, 19 are supported by hydraulic cylinders 21, 22, 23, 24 in a vertically movable manner in synchronization with each other, and the auxiliary front wheels 16 are diagonally arranged.
Hydraulic motors 25 and 26 are attached to the auxiliary rear wheel 19 and can be driven and rotated.

Here, the support structure of the auxiliary front wheels 16, 17 and the auxiliary rear wheels 18, 19 to the vehicle body will be described. The structure of each auxiliary wheel 16, 17, 18, 19 is substantially the same except for the presence or absence of a hydraulic motor. The structure of the auxiliary wheel 16 will be described below.

As shown in FIG. 3, the tire 31 is supported by a disc wheel 32, and this disc wheel 32 is attached via a brake disc 33 to a hub (not shown) fixed to the shaft end of the axle 34. . The suspension 35 is composed of an upper arm 36, a lower arm 37, and a shock absorber 38. The hydraulic cylinder 21 is a movable drive rod 39.
The auxiliary front wheel 16 is rotatably attached to the tip of the drive rod 39. The hydraulic cylinder 21 is attached to the shock absorber 38 via a mounting bracket 40. Although not shown in FIG. 3, the hydraulic motor 25 is mounted on the axle of the auxiliary front wheel 16.

Therefore, as shown by the solid line in FIG. 3, unless hydraulic oil is supplied to the hydraulic cylinder 21, the drive rod 39 does not operate, the auxiliary front wheel 16 is in the raised position, and the front wheel 12 contacts the road surface. Supports the vehicle. On the other hand, when hydraulic pressure is supplied to the hydraulic cylinder 21, the drive rod 39 operates to lower the auxiliary front wheel 16, and the auxiliary front wheel 16 contacts the road surface and lifts the vehicle, as indicated by the chain double-dashed line in FIG. The front wheels 12 move away from the road surface.

In the above-described auxiliary steering apparatus of this embodiment, the hydraulic cylinders 21, 22, 23, 24 for moving up and down the auxiliary wheels 16, 17, 18, 19 and the auxiliary front wheel 16 are provided.
And hydraulic motors 25, 2 for driving and rotating the auxiliary rear wheel 19
6 is operated by a hydraulic drive system of a power steering device mounted on the vehicle.

As shown in FIG. 1, an oil pump 41 driven by the operation of an engine (not shown) is connected to a reservoir tank 42, and is also connected to a power steering (P / S) valve 43 via an oil passage P1. This P /
The S valve 43 has a hydraulic cylinder 4 for power steering.
4 are connected. The P / S valve 43 is opened and closed according to the twist angle of a torsion bar (not shown) by the steering of the vehicle steering 45, and the opening / closing operation of the P / S valve 43 causes hydraulic pressure to act on the hydraulic cylinder 44. That is, the hydraulic cylinder 44 is configured such that the piston 47 is supported in the cylinder 46 so as to be movable in the axial direction.
Two oil chambers 48, 49 are formed by partitioning, and P /
The S valve 43 and the oil chambers 48 and 49 are connected by oil passages P2 and P3. Therefore, the piston 47 is operated by supplying and discharging the hydraulic oil from the oil pump 41 to the oil chambers 48 and 49 via the P / S valve 43.

A switching valve 50 is provided in the middle of an oil passage P1 from the oil pump 41 to the P / S valve 43. The switching valve 50 is used for raising and lowering a hydraulic cylinder via an oil passage P4 branched from the oil passage P1. It is connected to the valve 51. The lift valve 51 is connected to the oil chambers 52, 53 of the hydraulic cylinders 21, 22, 23, 24 via oil passages P5, P6. A reservoir tank 42 is connected to the lifting valve 51.

On the other hand, the oil chambers 48 and 49 of the hydraulic cylinder 44 for power steering are connected to the auxiliary wheel drive valve 54 via oil passages P7 and P8, and this drive valve 54 is connected to the oil passage P9 and P9. It is connected to the hydraulic motor 25 of the auxiliary front wheel 16 via P10. Also, the drive valve 5
4 is connected to the auxiliary wheel drive direction switching valve 55 via these oil passages P9 and P10, and this drive direction switching valve 55 is connected to the hydraulic motor 26 of the auxiliary rear wheel 19 via oil passages P11 and P12. ing.

As described above, the auxiliary steering device of this embodiment has
From the hydraulic pump 41 to the oil passage P1-the switching valve 50-the oil passage P
4-Elevating valve 51-First hydraulic pressure supply / discharge passage leading to the hydraulic cylinders 21, 22, 23, 24 (oil chambers 52, 53) via the oil passages P5, P6, and the hydraulic passage 41 from the hydraulic pump 41 to the switching valve 50-P / S valve 43-oil passages P2, P3-hydraulic cylinder 44 (oil chambers 48, 49) -oil passages P7, P8-driving valve 54-oil passages P9, P10 and hydraulic motor 2
5, and drive direction switching valve 55-oil passages P11, P12
A second hydraulic pressure supply / discharge path is provided to reach the hydraulic motor 26 via.

The control device 61 of the auxiliary steering device includes the hydraulic cylinders 21, 22, 23, 24 and the hydraulic motor 2.
Auxiliary wheel lifting switch 62 for operating 5, 26
And an auxiliary wheel drive / turning switch 63. The auxiliary wheel raising / lowering switch 62 is connected to the switching valve 50 and the raising / lowering valve 51, and the auxiliary wheel driving / turning switch 63 is connected to the driving valve 54 and the driving direction switching valve 55. Therefore, each switch 62, 63
By switching operation of each valve 50, 51, 5
The hydraulic oil can be supplied and discharged by performing opening and closing operations of 4, 55.

That is, as shown in FIG. 1, the switching valve 50 is set to the first state (display state) when not energized, and supplies the discharge oil from the hydraulic pump 41 to the P / S valve 43. On the other hand, when the switching valve 50 is energized, it is switched to the second state (lower display state), and the oil discharged from the hydraulic pump 41 is supplied to the lifting valve 51. Lifting valve 5
When 1 is not energized, the first state (display state) is set, the supply port is closed, and each hydraulic cylinder 21, 22, 23,
The hydraulic oil is not supplied to or discharged from the valve 24, and the operation is stopped. On the other hand, when the lifting valve 51 is first energized, the second valve 51
It is switched to the state (upper display state), and the working oil from the oil passage P4 is supplied to the oil chamber 5 of each hydraulic cylinder 21, 22, 23, 24.
2 while discharging the hydraulic oil in the oil chamber 53 to the reservoir tank 42,
2, 23 and 24 operate (extend). Further, when the lifting valve 51 is secondly energized, it is switched to the third state (lower side display state), and the working oil from the oil passage P4 is transferred to each hydraulic cylinder 2.
The hydraulic cylinders 21, 22, 23, 24 are operated (shortened) by supplying hydraulic oil 53, 22, 23, 24 to the hydraulic chambers 53 and discharging the hydraulic oil in the hydraulic chambers 52 to the reservoir tank 42.

When the drive valve 54 is not energized, it is set to the first state (display state), the supply port is closed, and the hydraulic oil is not supplied to or discharged from the hydraulic motors 25 and 26. , 26 cannot be driven. On the other hand, when the drive valve 54 is energized, it is switched to the second state (upper display state), and the oil passages P7 and P9 and the oil passages P8 and P1.
The hydraulic fluid can be supplied to and discharged from the hydraulic motors 25 and 26 by communicating with 0. Therefore, when the steering 45 is steered in the moving direction of the vehicle at this time, the pressure in the oil chamber 48 or 49 of the power steering hydraulic cylinder 44 rises, and the working oil flows into the oil passages P7, P9 or P8. P10
Is supplied from one side of the hydraulic motor 25, and the hydraulic motor 25 can be normally or reversely driven.

When the drive direction switching valve 55 is not energized, it is set to the first state (display state), and the oil passages P9 and P1 are set.
1. The hydraulic fluid can be supplied and discharged from one side of the hydraulic motor 26 by communicating with the oil passages P10 and P12. Therefore,
At this time, when the steering 45 is steered in the moving direction of the vehicle, the oil chamber 4 of the power steering hydraulic cylinder 44 is moved.
The pressure of 8 or 49 rises and the hydraulic oil flows into the oil passages P7, P
9 and P11 or P8, P10 and P12 are supplied from one side of the hydraulic motor 26,
Can be normally or reversely driven, and at this time, the hydraulic motors 25 and 26 rotate in the same direction, and the vehicle body moves laterally. On the other hand, when the drive direction switching valve 55 is energized, it is switched to the second state (lower display state), and the oil passages P9 and P12,
The oil passages P10 and P11 communicate with each other, so that the hydraulic oil can be supplied and discharged from the other side of the hydraulic motor 26. Therefore, when the steering 45 is steered in the moving direction of the vehicle at this time, the oil chamber 48 of the hydraulic cylinder 44 for power steering is
Alternatively, the pressure at 49 rises and the hydraulic oil flows into the oil passages P7, P.
It is supplied from the other side of the hydraulic motor 26 by 9, P12 or P8, P10, P11.
Can be driven in the opposite direction to the hydraulic motor 25, at which time the vehicle body makes a rotational movement.

The hydraulic cylinders 21, 22, 23,
24, the amount of movement, that is, each auxiliary wheel 16, 17, 1
Detection sensors 64 for detecting the amount of vertical movement of 8 and 19 are provided respectively, and the detection result of the detection sensors 64 is input to the control device 61. Further, the operation switch (SW) signal 65 of the parking brake (P / B) is input to the control device 61, and if the P / B SW signal 65 is not input for safety, The switch signals of the switches 62 and 63 are not output. Further, a driving power supply (12V) 66 is connected to the control device 61.

The operation of the above-described auxiliary steering apparatus of this embodiment will be described. For example, when the vehicle is moved to the right in the traveling direction for parallel parking in a narrow place, the parking brake of the vehicle is activated and the SW signal 65 is input to the control device 61, as shown in FIG. After confirming that the changeover valve 50 is operated, the auxiliary wheel raising / lowering switch 62 is operated to the “elevated” position.
Is energized to switch to the second state (lower display state) and the lifting valve 51 is energized to the second state (upper display state).
Switch to. Then, the oil discharged from the hydraulic pump 41 is supplied to the lifting valve 51 by the oil passages P1 and P4, and further, the hydraulic cylinders 21, 22, 23, and
The hydraulic cylinders 21, 2 are supplied to the oil chamber 52 of 24
2,23,24 are extended. Therefore, each auxiliary wheel 16, 1
When the wheels 7, 18, 19 descend and come into contact with the road surface, the wheels 12, 13, 14, 15 are separated from the road surface and the vehicle is lifted.

The detection sensor 64 is used for each hydraulic cylinder 21, 2.
2, 23, 24 are detected and the hydraulic cylinders 21, 22, 23, 24 are operated by a predetermined amount, that is, the wheels 12, 13, 14, 15 are completely separated from the road surface and the vehicle is lifted. Once supported and supported, the switching valve 50 is operated by operating the auxiliary wheel lifting / lowering switch 62 to the “stop” position.
Is stopped to switch to the first state (display state), and the lifting valve 51 is stopped to be switched to the first state (display state). Then, the oil supply from the hydraulic pump 41 to the hydraulic cylinders 21, 22, 23, 24 is stopped, and the hydraulic cylinders 21, 22, 23, 24 are locked, and the auxiliary wheels 16, 17, 18, 19 are also in that state. Held in position.

From this state, by operating the auxiliary wheel drive / turning switch 63 to the "drive" position, the drive valve 5
4 is energized to switch to the second state (upper display state) and the drive direction switching valve 55 is maintained in the non-energized first state (display state), and the oil passages P7, P9 and P11 and the oil passages P8 and P are set.
10 and P12 communicate with each other. When the steering 45 of the vehicle is steered to the right, the pressure in the oil chamber 49 of the power steering hydraulic cylinder 44 rises, and the oil passage P
The hydraulic oil flows from the side 8 and is supplied from the upper side of the hydraulic motors 25 and 26 in FIG.
5, 26 are driven in the normal direction. Therefore, this hydraulic motor 2
The auxiliary wheels 16 and 19 are rotated by the normal rotation driving of the wheels 5 and 26, and the vehicle can move to the right. Then, by adjusting the steering force of the steering 45 at this time,
The lateral movement speed of the vehicle can be made variable.

To stop the vehicle moving to the right, the steering 45, which has been steered to the right, is returned to reduce the steering force to 0, and the supply pressures of the oil chambers 48 and 49 of the power steering hydraulic cylinder 44 are substantially equal. Therefore, the hydraulic oil is not supplied to the oil passage P8, and the driving of the hydraulic motors 25 and 26 is stopped. After that, the auxiliary wheel drive / turn switch 6
3 is moved to the "stop" position to stop the energization of the drive valve 54 and switch to the first state (display state),
By operating the auxiliary wheel lifting / lowering switch 62, the switching valve 50 is energized to switch to the second state (lower display state) and the lifting valve 51 is switched to the third state (lower display state). Then, the oil discharged from the hydraulic pump 41 is supplied to the lifting valve 51 by the oil passage P4, and further, the hydraulic cylinders 21, 22, 23, 2 are supplied by the oil passage P6.
4 is supplied to the oil chamber 53, and the hydraulic cylinders 21 and 2 are supplied.
2,23,24 is shortened. Therefore, each auxiliary wheel 16, 1
While 7, 18, 19 rise and move away from the road surface, the vehicle descends and each wheel 12, 13, 14, 15 grounds on the road surface to support the vehicle.

Further, in the auxiliary steering system of this embodiment, the vehicle can be turned not only laterally but also at that location. That is, as described above, the hydraulic cylinders 21, 22, 23, and 24 are expanded to extend the auxiliary wheels 1.
When the auxiliary wheel drive / turning switch 63 is operated to the "turning" position from a state in which the vehicle is lifted and supported by the vehicle 6, 6, 18, 18, and the drive valve 54 is energized to the second state (upper display state). ) And energize the drive direction switching valve 55 to switch to the second state (lower display state) to connect the oil passages P7, P9 and P12 and the oil passages P8, P10 and P11, respectively. When the steering wheel 45 is steered in the right turning direction of the vehicle, the pressure in the oil chamber 49 of the power steering hydraulic cylinder 44 rises and hydraulic oil flows from the oil passage P8 side. Then, the hydraulic oil is supplied to the hydraulic motor 25 from the upper side in FIG.
5 is driven to rotate in the normal direction, while the hydraulic motor 26 is supplied with this hydraulic oil from the lower side in FIG.
Drives in reverse. Therefore, the auxiliary wheels 16 and 19 are rotationally driven in reverse by the hydraulic motors 25 and 26, respectively, so that the vehicle can turn to the right.

As described above, in the auxiliary steering apparatus of this embodiment, the steering direction, movement start operation, and movement speed of the vehicle are controlled by steering the steering wheel. It ’s good,
By using the familiar steering wheel, erroneous operation is eliminated.

In this embodiment, each auxiliary wheel 1
Since 6, 17, 18, 19 are mounted on the vehicle suspension 35, these auxiliary wheels 16, 17, 18, 1
The stroke of each hydraulic cylinder 21, 22, 23, 24 may be small at the time of lowering 9, and the auxiliary wheels 16, 1
The suspension acts even when the vehicle travels by 7, 18, and 19, and the riding comfort is good.

FIG. 4 shows a schematic structure of an auxiliary steering device according to another embodiment of the present invention. The members having the same functions as those in the above-described embodiment are designated by the same reference numerals, and the duplicated description will be omitted.

As shown in FIG. 4, the oil pump 41 includes a power steering (P / S) valve 4 via an oil passage P1.
3, a power steering hydraulic cylinder 44 is connected to the P / S valve 43. The hydraulic cylinder 44 is constructed by a piston 47 supported in a cylinder 46 so as to be movable in the axial direction, and has two oil chambers 48, 49.
Are formed by partitioning, and steering switches 71, 72 which are operated by the moving contact of the piston 47 are attached to the corners of the oil chambers 48, 49. And P /
The S valve 43 and the oil chambers 48 and 49 are connected by oil passages P2 and P3. Therefore, the piston 47 is operated by supplying and discharging the hydraulic oil from the oil pump 41 to the oil chambers 48 and 49 via the P / S valve 43. The oil pump 41 is connected to a hydraulic cylinder lifting valve 51 from a branch portion 73 of an oil passage P1 reaching the P / S valve 43 via an oil passage P4. The lift valve 51 is connected to the oil chambers 52, 53 of the hydraulic cylinders 21, 22, 23, 24 via oil passages P5, P6.

On the other hand, the oil chambers 48 and 49 of the hydraulic cylinder 44 for power steering are connected to the auxiliary wheel drive valve 54 via oil passages P7 and P8, and this drive valve 54 is connected to the oil passage P9 and P9. It is connected to the hydraulic motor 25 of the auxiliary front wheel 16 via P10. Also, the drive valve 5
4 is connected to the auxiliary wheel drive direction switching valve 55 via these oil passages P9 and P10, and this drive direction switching valve 55 is connected to the hydraulic motor 26 of the auxiliary rear wheel 19 via oil passages P11 and P12. ing.

As described above, the auxiliary steering device of this embodiment has
From hydraulic pump 41 to oil passage P1-P / S valve 43 (branch portion 73) -oil passage P4-up / down valve 51-oil passages P5, P
6 through hydraulic cylinders 21, 22, 23, 24 (oil chamber 5
2, 53) to the first hydraulic pressure supply / discharge passage, and from the hydraulic pump 41 to the oil passage P1-P / S valve 43 (branch portion 73) -oil passage P.
2, P3-hydraulic cylinder 44 (oil chambers 48, 49) -oil passages P7, P8-driving valve 54-oil passages P9, P10 through hydraulic motor 25, and drive direction switching valve 55-oil passages P11, P12. A second hydraulic pressure supply / discharge passage is provided to reach the hydraulic motor 26.

The control device 61 of the auxiliary steering device includes the hydraulic cylinders 21, 22, 23, 24 and the hydraulic motor 2.
Auxiliary wheel lifting switch 62 for operating 5, 26
And an auxiliary wheel drive / turning switch 63. The auxiliary wheel lifting / lowering switch 62 is connected to the lifting / lowering valve 51, and the auxiliary wheel driving / turning switch 63 is connected to the driving valve 54 and the driving direction switching valve 55. Therefore, the switching operation of the switches 62 and 63 can open and close the valves 51, 54 and 55 to supply and discharge the hydraulic oil.

That is, when the lift valve 51 is not energized, it is set to the first state (display state), the supply port is closed, and the hydraulic oil is not supplied to or discharged from the hydraulic cylinders 21, 22, 23, 24. , The operation has stopped. On the other hand, when the lifting valve 51 is first energized, it is in the second state (upper display state).
The oil passages P4 and P5 communicate with each other. Therefore,
If the steering 45 is steered in the moving direction of the vehicle at this time, the pressure in the oil chamber 48 or 49 of the power steering hydraulic cylinder 44 is rising, so that the hydraulic oil from the oil passage P4 is transferred to each hydraulic cylinder 21. , 22, 23,
The hydraulic cylinders 21, 2 are supplied to the oil chamber 52 of 24
2, 23 and 24 operate (extend). When the lifting valve 51 is energized for the second time, it is switched to the third state (lower display state), and the oil passages P4 and P6 are in communication. Therefore, when the steering 45 is steered in the moving direction of the vehicle at this time, the pressure in the oil chamber 48 or 49 of the power steering hydraulic cylinder 44 is rising, and therefore the oil passage P4 is used.
Hydraulic fluid from each hydraulic cylinder 21, 22, 23, 24
Of each hydraulic cylinder 21, 22, 2
3, 24 are activated (shortened).

The operation of the drive valve 54 and the drive direction switching valve 55 is the same as that of the above-mentioned embodiment, and the description thereof will be omitted.

Further, each hydraulic cylinder 21, 22, 23,
24, the amount of movement, that is, each auxiliary wheel 16, 17, 1
Detection sensors 64 for detecting the amount of vertical movement of 8 and 19 are provided respectively, and the detection result of the detection sensors 64 is input to the control device 61. Further, the detection signals of the steering switches 71 and 72 of the hydraulic cylinder 44 described above are input to the control device 61, and the control device 61 also includes a parking brake (P / B) operation switch ( SW) signal 65 is input. Further, a driving power supply (12V) 66 is connected to the control device 61.

The operation of the above-described auxiliary steering apparatus of this embodiment will be described. For example, when the vehicle is moved to the right in the traveling direction for parallel parking in a narrow place, the parking brake of the vehicle is activated and the SW signal 65 is input to the control device 61 as shown in FIG. After confirming that the
When 5 is steered to the right, the pressure in the oil chamber 49 of the power steering hydraulic cylinder 44 rises, the piston 47 moves in the cylinder 46 to the left in FIG. 1, the steering switch 71 is turned on, and the detection signal is controlled. Input to the device 61.

In this state, by operating the auxiliary wheel raising / lowering switch 62 to the "up" position, the oil discharged from the hydraulic pump 41 is supplied to the raising / lowering valve 51 by the oil passages P1 and P4, and further the oil passage P5. Depending on each hydraulic cylinder 21,2
The oil is supplied to the oil chambers 52, 23, 24, and the hydraulic cylinders 21, 22, 23, 24 extend. Therefore, each of the auxiliary wheels 16, 17, 18 and 19 descends to come into contact with the road surface, so that each of the wheels 12, 13, 14 and 15 separates from the road surface,
The vehicle is lifted. At this time, the oil passages P8, P
Since the supply port 9 is closed by the drive valve 54, hydraulic oil does not flow to the hydraulic motors 25 and 26.

By the detection sensor 64, the hydraulic cylinder 2
1, 22, 23, 24 are actuated by a predetermined amount and each wheel 12, 1
When it is confirmed that the vehicle has been lifted up with 3, 14, 15 completely separated from the road surface, the auxiliary wheel lifting switch 62
Is operated to the "stop" position, the energization of the lifting valve 51 is stopped and the state is switched to the first state (display state). Then, from the hydraulic pump 41 to each hydraulic cylinder 21, 22, 2
The oil supply to the hydraulic cylinders 21, 24 is stopped.
2,23,24 are locked and each auxiliary wheel 16,1
7, 18 and 19 are also held in that position.

From this state, by operating the auxiliary wheel drive / turning switch 63 to the "drive" position, the drive valve 5
4 is energized to switch to the second state (upper display state) and the drive direction switching valve 55 is maintained in the non-energized first state (display state), and the oil passages P7, P9 and P11 and the oil passages P8 and P are set.
10 and P12 communicate with each other. Then, the oil passage P8
The hydraulic oil flows from the side and is supplied from the upper side of the hydraulic motors 25 and 26 in FIG.
26 is driven in the normal direction. Therefore, this hydraulic motor 25, 2
The auxiliary wheels 16 and 19 are rotated by the normal rotation drive of 6, and the vehicle can move to the right. Then, by adjusting the steering force of the steering 45 at this time, the lateral movement speed of the vehicle can be made variable.

In order to turn the vehicle at that location,
The auxiliary wheel drive / turn switch 63 is operated to the "turn" position from a state in which the hydraulic cylinders 21, 22, 23, 24 are extended and the auxiliary wheels 16, 17, 18, 19 lift and support the vehicle. As a result, the drive valve 54 is energized to switch to the second state (upper display state) and the drive direction switching valve 55 is energized to switch to the second state (lower display state), and the oil passages P7, P9, and P12, Oil passages P8, P10 and P
11 and 11, respectively. Then, the pressure of the oil chamber 49 of the hydraulic cylinder 44 for power steering rises and the working oil flows from the oil passage P8 side, and the working oil is supplied to the hydraulic motor 25 from the upper side in FIG.
5 is driven to rotate in the normal direction, while the hydraulic motor 26 is supplied with this hydraulic oil from the lower side in FIG.
Drives in reverse. Therefore, the auxiliary wheels 16 and 19 are rotationally driven in reverse by the hydraulic motors 25 and 26, respectively, so that the vehicle can turn to the right.

In each of the above-described embodiments, the left and right auxiliary front wheels 16 and 17 and the auxiliary rear wheel 1 provided on the vehicle are provided.
8, 19 with the axles being the front wheels 12, 13 and the rear wheels 14, 1
It was almost orthogonal to the axle of 5, but each auxiliary wheel 1
6, 17, 18, and 19 may be supported so as to be steerable. FIG. 5 schematically shows another auxiliary wheel support structure in the auxiliary steering device of the present invention.

As shown in FIG. 5, the auxiliary front wheels 16 and 17 are rotatably supported by support brackets 81 and 82, respectively, and the support brackets 81 and 82 are hydraulic cylinders (not shown) for moving the auxiliary front wheels 16 and 17 up and down. Is supported so as to be able to move up and down, and a hydraulic motor 25 is attached to one of the auxiliary front wheels 16 so that it can be driven and rotated.
Connecting portions 83 and 84 are integrally formed on opposite side surfaces of the support brackets 81 and 82, respectively.
4 are connected by a connecting rod 85. An auxiliary wheel steering motor 86 is attached to the vehicle body (not shown),
A base end of a crank lever 87 is connected to an output shaft of the auxiliary wheel steering motor 86. On the other hand, one end of the operating rod 88 is connected to the intermediate portion of the connecting rod 85, and the other end of the operating rod 88 is connected to the tip of the crank lever 87.

Thus, normally, as shown in FIG. 5A, the auxiliary front wheels 16 and 17 face the same direction and drive the hydraulic motor 25 to move the vehicle laterally. it can. On the other hand, as shown in FIG. 5B, when the auxiliary wheel steering motor 86 is driven to move the operating rod 88 downward through the crank lever 87,
The connecting rod 85 also moves in the same direction to move the auxiliary front wheels 16, 1
7, the auxiliary front wheels 16 and 17 face different directions. Therefore, the vehicle can be turned by driving the hydraulic motor 25 in this state.

In each of the above-described embodiments, the steering force of the steered steering wheel 45 is returned to 0 to stop the vehicle moving by the auxiliary wheels 16, 17, 18, and 19 so that the hydraulic cylinder 44 drives the hydraulic motor. This was done by stopping the supply of hydraulic oil to 25, 26 and stopping the drive of the hydraulic motors 25, 26. However, in consideration of safety, each auxiliary wheel 16, 17, 18, 19 is provided with a brake or the like. You can also wear it. Further, in each of the above-described embodiments, the vehicle is provided with the four auxiliary wheels 16, 17, 18, and 19, but the auxiliary wheels 16, 17, 18, and 19 are provided between the front wheels 12 and 13 and the rear wheels 14 and 15, respectively, to operate one by one. Alternatively, only one of them may be provided. Furthermore, the hydraulic motors 25, 2
6 may be changed to an electric motor.

[0048]

As described above in detail with reference to the embodiments, according to the auxiliary steering device of the present invention, the auxiliary wheel is provided in the lower portion of the vehicle body and the auxiliary wheel is supported by the elevating mechanism so as to be able to move up and down. Since the auxiliary wheels are rotatably supported by the drive motor and the auxiliary wheels are supported on the vehicle body via the vehicle suspension, the vehicle body lifted by the elevating mechanism ascends together with the suspension, which reduces the elevating stroke of the elevating mechanism. The device can be made compact. In addition, the lifted vehicle body is supported by the auxiliary wheels on the road surface via the suspension, so that when the vehicle is driven by the auxiliary wheels, the suspension acts in the same manner as in normal running, and the riding comfort is impaired. There is no.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an auxiliary steering device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a vehicle equipped with the auxiliary steering device of the present embodiment.

FIG. 3 is a mounting state diagram of an auxiliary steering device.

FIG. 4 is a schematic configuration diagram of an auxiliary steering device according to another embodiment of the present invention.

FIG. 5 is a schematic view showing another auxiliary wheel support structure in the auxiliary steering device of the present invention.

[Explanation of symbols]

 11 Vehicle 12,13 Front Wheel 14,15 Rear Wheel 16,17 Auxiliary Front Wheel 18,19 Auxiliary Rear Wheel 21,22,23,24 Hydraulic Cylinder 25,26 Hydraulic Motor 35 Suspension 36 Upper Arm 37 Lower Arm 38 Shock Absorber 41 Hydraulic Pump 43 Power Steering valve 44 Hydraulic cylinder for power steering 45 Steering 50 Switching valve 51 Hydraulic cylinder lifting valve 54 Auxiliary wheel drive valve 55 Auxiliary wheel drive direction switching valve 61 Control device 62 Auxiliary wheel lifting switch 63 Auxiliary wheel driving / turning switch

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takao Morita 5-3-8, Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Tatsuya Kamada 5-3-8, Shiba, Minato-ku, Tokyo Mitsubishi Automobile Industry Co., Ltd. (72) Inventor Yasutaka Taniguchi 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Industry Co., Ltd.

Claims (1)

[Claims] 1. An auxiliary steering device for a vehicle, wherein an auxiliary wheel is provided in a lower portion of a vehicle body, and the auxiliary wheel is supported by an elevating mechanism so as to be able to move up and down and is rotatably supported by a drive motor. An auxiliary steering device, which is supported on the vehicle body via the suspension of the vehicle.