JP2950119B2 - Auxiliary steering system for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary steering apparatus for a vehicle, which is provided with auxiliary wheels on a vehicle body for parallel parking of a vehicle in a narrow place and which can move the vehicle laterally.

[0002]

2. Description of the Related Art In recent years, in order to parallel park a vehicle in a narrow place, auxiliary wheels are provided at the front and rear portions of the vehicle body in addition to steering wheels and drive wheels, and when necessary, the auxiliary wheels are lowered to lower the vehicle body. It has been considered that the vehicle can be moved in the lateral direction by lifting and driving the auxiliary wheels in this state. Conventionally, such a drive control device for an auxiliary wheel is disclosed in Japanese Unexamined Patent Publication No.
There is one disclosed in Japanese Patent Application Laid-open No. 2 (1994).

In the device disclosed in this publication, an auxiliary wheel that can be driven and rotated is mounted on a rear portion of a vehicle body via a support arm, and the auxiliary wheel can be moved up and down by a hydraulic jack mechanism, and a hydraulic motor is mounted on the auxiliary wheel. A hydraulic jack mechanism, a hydraulic motor, and a hydraulic pump for power steering are mounted and connected by a first oil passage and a second oil passage. Then, the hydraulic pressure is supplied from the hydraulic pump to the hydraulic jack mechanism via the first oil passage, and the auxiliary wheels descend to lift the vehicle. In this state, the hydraulic pressure is applied from the hydraulic pump to the hydraulic motor via the second oil passage. The vehicle can move in the lateral direction when the supplied auxiliary wheels are driven.

[0004]

In the conventional auxiliary wheel steering apparatus described above, the auxiliary wheels are attached to the rear of the vehicle body via support arms, and the auxiliary wheels are rotated by rotating the support arms by a hydraulic jack mechanism. And the vehicle body is lifted to separate the rear wheel from the road surface. In this state, the hydraulic motor is operated to rotate the auxiliary wheels. However, generally, the wheels are supported by the vehicle body via a suspension, a coil spring, and the like. When the vehicle body is lifted, the suspension strokes due to extension of the coil spring, for example, and the wheels lower relative to the body. Therefore, the wheels cannot be lifted off the road surface unless the vehicle body is lifted to some extent in consideration of the amount. Therefore, in the above-mentioned 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.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide an auxiliary wheel steering device in which the size of the device is reduced.

[0006]

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

[0007]

Since the auxiliary wheels are supported by the vehicle body via the suspension of the vehicle, when the vehicle body is lifted by the lifting mechanism, the vehicle body rises together with the suspension, and the lifting stroke of the lifting mechanism may be small. Also,
The lifted vehicle body is supported by the auxiliary wheels on the road via the elevating mechanism and the suspension. Even when the vehicle is running with the auxiliary wheels, the suspension acts as usual and the ride comfort is not impaired.

[0008]

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

FIG. 1 shows a schematic configuration of an auxiliary steering device according to an embodiment of the present invention, FIG. 2 shows a schematic view of a vehicle equipped with the auxiliary steering device of the present embodiment, and FIG. 3 shows an attached state of the auxiliary steering device. .

In the auxiliary steering apparatus according to the present embodiment, as shown in FIG. 2, a vehicle 11 includes left and right front wheels 12, 13 and rear wheels 14, 15, and also has left and right auxiliary front wheels 16, 1 as shown in FIG.
7 and auxiliary rear wheels 18 and 19. The axles of these auxiliary wheels 16, 17, 18, 19 are arranged substantially orthogonal to the axles of the front wheels 12, 13 and the rear wheels 14, 15. The auxiliary wheels 16, 17, 18, 19 are supported by hydraulic cylinders 21, 22, 23, 24 so as to be able to move up and down in synchronization with each other.
Hydraulic motors 25 and 26 are mounted on the auxiliary rear wheel 19 and can be driven and rotated.

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

As shown in FIG. 3, the tire 31 is supported by a disc wheel 32, which is mounted on a hub (not shown) fixed to the shaft end of an axle 34 via a brake disc 33. . The suspension 35 includes an upper arm 36, a lower arm 37, and a shock absorber 38. The hydraulic cylinder 21 has a movable drive rod 39.
The auxiliary front wheel 16 is rotatably attached to the distal end of the drive rod 39. The hydraulic cylinder 21 is mounted on the shock absorber 38 via the 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, if the hydraulic oil is not supplied to the hydraulic cylinder 21, the drive rod 39 does not operate, the auxiliary front wheel 16 is in the ascending position, and the front wheel 12 contacts the road surface. Supports the vehicle. On the other hand, when the hydraulic pressure is supplied to the hydraulic cylinder 21, the auxiliary front wheel 16 is lowered by operating the drive rod 39, and as shown by the two-dot chain line in FIG. And the front wheels 12 are separated from the road surface.

In the above-described auxiliary steering device of the present embodiment, the hydraulic cylinders 21, 22, 23, 24 for raising and lowering the auxiliary wheels 16, 17, 18, 19, and the auxiliary front wheel 16
And hydraulic motors 25 and 2 for driving and rotating the auxiliary rear wheel 19
Reference numeral 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 operation of an engine (not shown) is connected to a reservoir tank 42 and 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 opens and closes according to the torsion angle of a not-shown torsion bar when the steering 45 of the vehicle is steered. The opening / closing operation of the P / S valve 43 applies a hydraulic pressure to the hydraulic cylinder 44. That is, the hydraulic cylinder 44 is configured such that a piston 47 is supported in a cylinder 46 so as to be movable in the axial direction.
Oil chambers 48 and 49 are partitioned and formed.
The S valve 43 and each of the oil chambers 48 and 49 are connected by oil paths P2 and P3. Accordingly, the working oil is supplied and discharged from the oil pump 41 to each of the oil chambers 48 and 49 via the P / S valve 43, so that the piston 47 operates.

A switching valve 50 is provided in the middle of an oil passage P1 extending 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 a valve 51. The elevating valve 51 is connected to the oil chambers 52, 53 of the hydraulic cylinders 21, 22, 23, 24 via oil paths P5, P6. In addition, the reservoir tank 42 is connected to the elevating valve 51.

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

As described above, the auxiliary steering device according to the present embodiment includes:
From hydraulic pump 41 to oil passage P1-switching valve 50-oil passage P
4—a valve 51 for ascending and descending—a first hydraulic supply / discharge passage leading to the hydraulic cylinders 21, 22, 23, 24 (oil chambers 52, 53) via the oil passages P5, P6, and an oil passage P1-switching valve from the hydraulic pump 41. 50-P / S valve 43-oil passages P2, P3-hydraulic cylinder 44 (oil chambers 48, 49) -oil passages P7, P8-drive valve 54-hydraulic motor 2 via oil passages P9, P10
5, and drive direction switching valve 55-oil passages P11, P12
And a second hydraulic supply / discharge path leading to the hydraulic motor 26 through the second hydraulic supply / discharge path.

The control device 61 of the auxiliary steering device includes the hydraulic cylinders 21, 22, 23, 24 and the hydraulic motor 2
Auxiliary wheel elevating switch 62 for operating 5, 26
And an auxiliary wheel drive / turn switch 63. The auxiliary wheel lifting / lowering switch 62 is connected to the switching valve 50 and 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, each of the switches 62 and 63
The switching operation of each valve 50, 51, 5
4, 55 can be opened and closed to supply and discharge hydraulic oil.

That is, as shown in FIG. 1, the switching valve 50 is set to the first state (display state) when power is not supplied, 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, the state is switched to the second state (the lower display state), and the discharge oil from the hydraulic pump 41 is supplied to the elevating valve 51. Lifting valve 5
1 is set to the first state (display state) when power is not supplied to the hydraulic cylinders 21, 22, 23, and 23.
The supply and discharge of the hydraulic oil to and from the pump 24 are not performed, and the operation is stopped. On the other hand, during the first energization of the lift valve 51, the second
State (upper display state), and the hydraulic oil from the oil passage P4 is supplied to the oil chambers 5 of the hydraulic cylinders 21, 22, 23, 24.
2 and discharges the hydraulic oil in the oil chamber 53 to the reservoir tank 42, so that the hydraulic cylinders 21 and
2, 23, 24 operate (extend). Further, at the time of the second energization of the elevating valve 51, the state is switched to the third state (the lower display state), and the hydraulic oil from the oil passage P4 is supplied to each hydraulic cylinder 2
The hydraulic cylinders 21, 22, 23, and 24 are operated (shortened) by supplying the hydraulic oil in the oil chambers 52 to the reservoir tank 42 while supplying the oil to the oil chambers 53 of 1, 22, 23, and 24.

When the drive valve 54 is not energized, it is set to the first state (display state), the supply port is closed, and supply and discharge of hydraulic oil to and from the hydraulic motors 25 and 26 are not performed. , 26 cannot be driven. On the other hand, when the drive valve 54 is energized, the state is switched to the second state (upper display state), and the oil paths P7 and P9, and the oil paths P8 and P1
0 communicates with the hydraulic motors 25 and 26 to supply and discharge hydraulic oil. Therefore, if the steering wheel 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 increases, and the hydraulic oil is supplied to the oil passages P7, P9 or P8. P10
Thus, the hydraulic motor 25 is supplied from one side of the hydraulic motor 25 and can be driven to rotate forward or reverse.

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
1. Hydraulic motor 26 can be supplied and discharged from one side of hydraulic motor 26 by communicating with 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.
8 or 49, the hydraulic oil rises and oil passages P7, P
9, P11 or P8, P10, P12 from one side of the hydraulic motor 26.
Can be driven forward or reverse, 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 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 of 49 increases, and the hydraulic oil is
9, P12 or P8, P10, P11 from the other side of the hydraulic motor 26.
Can be driven in the direction opposite to the hydraulic motor 25, and at this time, the vehicle body rotates.

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

The operation of the above-described auxiliary steering apparatus according to the present embodiment will be described. For example, when the vehicle is moved rightward in the traveling direction to perform parallel parking in a narrow place, as shown in FIG. 1, the parking brake of the vehicle is activated and the SW signal 65 is input to the control device 61. After confirming that the switching valve 50 is operated, the auxiliary wheel elevating switch 62 is operated to the “elevated” position, whereby the switching valve 50
To switch to the second state (lower display state) and power to the elevating valve 51 to the second state (upper display state).
Switch to. Then, the oil discharged from the hydraulic pump 41 is supplied to the lifting / lowering valve 51 through the oil passages P1 and P4, and further, the hydraulic cylinders 21, 22, 23,
24, and supplied to the hydraulic chambers 21 and 24.
2, 23, 24 expand. Therefore, each auxiliary wheel 16, 1
When the wheels 7, 18, 19 descend and touch the road surface, the wheels 12, 13, 14, 15 separate from the road surface, and the vehicle is lifted.

The detection sensor 64 is provided for each of the hydraulic cylinders 21 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. When the auxiliary wheel lifting / lowering switch 62 is operated to the “stop” position, the switching valve 50
Is stopped and the state is switched to the first state (display state). At the same time, the state of the elevation valve 51 is stopped and the state is switched to the first state (display state). Then, oil supply from the hydraulic pump 41 to each of the hydraulic cylinders 21, 22, 23, 24 is stopped, the hydraulic cylinders 21, 22, 23, 24 are locked, and the auxiliary wheels 16, 17, 18, 19 are also locked. Held in position.

By operating the auxiliary wheel drive / turn switch 63 to the "drive" position from this state, the drive valve 5 is turned on.
4 to switch to the second state (upper display state) and maintain the drive state switching valve 55 in the first state (display state) in which the drive direction switching valve 55 is not energized, and the oil paths P7, P9, and P11, and the oil paths P8 and P
10 and P12 are communicated 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 increases, and the oil passage P
Hydraulic oil flows from the hydraulic motor 25 and the hydraulic motors 25 and 26 in FIG.
5, 26 are driven forward. Therefore, this hydraulic motor 2
The auxiliary wheels 16, 19 are rotated by the forward rotation of the wheels 5, 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 zero, and the supply pressures of the oil chambers 48, 49 of the hydraulic cylinder 44 for power steering are substantially equal. Then, the hydraulic oil is no longer supplied to the oil passage P8, and the driving of the hydraulic motors 25 and 26 is stopped. Then, the auxiliary wheel drive / turn switch 6
3 is operated to the "stop" position, after the energization of the drive valve 54 is stopped and switched to the first state (display state),
By operating the auxiliary wheel elevating switch 62, the switching valve 50 is energized to switch to the second state (lower display state), and the elevating valve 51 is energized to switch to the third state (lower display state). Then, the discharge oil from the hydraulic pump 41 is supplied to the lifting / lowering valve 51 through the oil passage P4, and further, the respective hydraulic cylinders 21, 22, 23, 2 through the oil passage P6.
The hydraulic cylinders 21 and
2, 23, 24 are shortened. Therefore, each auxiliary wheel 16, 1
While the vehicles 7, 18, and 19 rise and move away from the road surface, the vehicle descends and the wheels 12, 13, 14, and 15 contact the road surface to support the vehicle.

Further, in the auxiliary steering device according to the present embodiment, the vehicle can be turned not only in the lateral direction but also in the place. That is, each of the hydraulic cylinders 21, 22, 23, and 24 as described above is extended and each of the auxiliary wheels 1
When the auxiliary wheel drive / turn switch 63 is operated to the "turn" position from the state in which the vehicle is lifted and supported by the vehicles 6, 17, 18, and 19, the drive valve 54 is energized and 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 paths P7, P9, and P12, and the oil paths P8, P10, and P11 are communicated, respectively. Then, when the steering wheel 45 is steered in the right turning direction of the vehicle, the pressure in the oil chamber 49 of the hydraulic cylinder 44 for power steering increases, and hydraulic oil flows from the oil passage P8 side. Then, the hydraulic oil is supplied to the hydraulic motor 25 from above in FIG.
5, the hydraulic oil is supplied to the hydraulic motor 26 from below in FIG.
Drives in reverse. Accordingly, the auxiliary wheels 16, 19 are rotated in reverse by the hydraulic motors 25, 26, so that the vehicle can turn right.

As described above, in the auxiliary steering apparatus according to the present embodiment, the steering direction, the movement start operation, and the movement speed of the vehicle are performed by steering the steering. Good nature,
Performing with the familiar steering wheel eliminates erroneous operations.

In this embodiment, each auxiliary wheel 1
6, 17, 18, and 19 are mounted on the suspension 35 of the vehicle, so that the respective auxiliary wheels 16, 17, 18, 1
9, the strokes of the hydraulic cylinders 21, 22, 23, 24 may be small, and the auxiliary wheels 16, 1
The suspension works even when the vehicle is running according to 7, 18, and 19, and the riding comfort is good.

FIG. 4 shows a schematic configuration of an auxiliary steering device according to another embodiment of the present invention. Note that members having the same functions as those of the above-described embodiment are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 4, an oil pump 41 is connected to a power steering (P / S) valve 4 via an oil passage P1.
The power steering hydraulic cylinder 44 is connected to the P / S valve 43. The hydraulic cylinder 44 has a piston 47 supported in a cylinder 46 so as to be movable in the axial direction.
The steering switches 71, 72 that 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 each of the oil chambers 48 and 49 are connected by oil paths P2 and P3. Accordingly, the working oil is supplied and discharged from the oil pump 41 to each of the oil chambers 48 and 49 via the P / S valve 43, so that the piston 47 operates. The oil pump 41 is connected to a hydraulic cylinder lifting / lowering valve 51 from a branch portion 73 of an oil passage P1 reaching the P / S valve 43 via an oil passage P4. The elevating valve 51 is connected to the oil chambers 52, 53 of the hydraulic cylinders 21, 22, 23, 24 via oil paths P5, P6.

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

As described above, the auxiliary steering device according to the present embodiment includes:
Hydraulic pump 41 to oil passage P1-P / S valve 43 (branch 73) -oil passage P4-lift valve 51-oil passages P5, P
6 through the hydraulic cylinders 21, 22, 23, 24 (oil chamber 5
2, 53) and the hydraulic pump 41 to the oil passage P 1 -P / S valve 43 (branch 73) -oil passage P
2, P3-hydraulic cylinder 44 (oil chambers 48, 49) -oil passages P7, P8-drive valve 54-hydraulic motor 25 via oil passages P9, P10 and drive direction switching valve 55-oil passages P11, P12. A second hydraulic supply / discharge passage extending to the hydraulic motor 26 via the second hydraulic supply / discharge path is provided.

The control device 61 of the auxiliary steering device includes the hydraulic cylinders 21, 22, 23, 24 and the hydraulic motor 2
Auxiliary wheel elevating switch 62 for operating 5, 26
And an auxiliary wheel drive / turn 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 elevation valve 51 is not energized, it is set to the first state (display state), the supply port is closed, and supply / discharge of hydraulic oil to / from the hydraulic cylinders 21, 22, 23, 24 is not performed. , Operation has stopped. On the other hand, at the time of the first energization of the lift valve 51, the second state (upper display state).
And the oil passages P4 and P5 communicate with each other. Therefore,
At this time, if the steering 45 is steered in the moving direction of the vehicle, the pressure in the oil chamber 48 or 49 of the power steering hydraulic cylinder 44 is increased, so that the hydraulic oil from the oil passage P4 is , 22,23,
The hydraulic cylinders 21,
2, 23, 24 operate (extend). Further, at the time of the second energization of the elevating valve 51, the state is switched to the third state (the lower display state), and the oil passages P4 and P6 communicate with each other. Accordingly, 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 hydraulic cylinder 44 for power steering has increased, and the oil passage P4
From the hydraulic cylinders 21, 22, 23, 24
Of the hydraulic cylinders 21, 22, 2
3, 24 operate (shorten).

The operation of the drive valve 54 and the drive direction switching valve 55 is the same as that of the above-described embodiment, and therefore, the description is omitted.

Each of the hydraulic cylinders 21, 22, 23,
24 indicates the amount of movement, that is, each of the auxiliary wheels 16, 17, 1
A detection sensor 64 for detecting the amount of vertical movement of each of the sensors 8 and 19 is provided. The detection result of the detection sensor 64 is input to the control device 61. The control device 61 is configured to receive the detection signals of the steering switches 71 and 72 of the hydraulic cylinder 44 described above, and the control device 61 has a parking brake (P / B) operation switch (P / B). SW) signal 65 is input. Further, a drive power supply (12 V) 66 is connected to the control device 61.

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

In this state, by operating the auxiliary wheel lifting / lowering switch 62 to the "up" position, the discharge oil from the hydraulic pump 41 is supplied to the lifting / lowering valve 51 via the oil passages P1 and P4, and further, the oil passage P5 Each hydraulic cylinder 21,
The hydraulic cylinders 21, 22, 23, 24 are supplied to the oil chambers 52, 23, 24 and extend. Therefore, each of the auxiliary wheels 16, 17, 18, and 19 descends and touches the road surface, so that the wheels 12, 13, 14, and 15 separate 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.

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

By operating the auxiliary wheel drive / turn switch 63 to the "drive" position from this state, the drive valve 5 is turned on.
4 to switch to the second state (upper display state) and maintain the drive state switching valve 55 in the first state (display state) in which the drive direction switching valve 55 is not energized, and the oil paths P7, P9, and P11, and the oil paths P8 and P
10 and P12 are communicated with each other. Then, oilway P8
Hydraulic oil flows from the hydraulic motors 25 and 26 and is supplied from the upper side in FIG.
26 drives forward. Therefore, the hydraulic motors 25, 2
The auxiliary wheels 16 and 19 are rotated by the forward rotation of 6, and the vehicle can move to the right. At this time, by adjusting the steering force of the steering 45, the lateral movement speed of the vehicle can be made variable.

To turn the vehicle at that location,
From the state where the hydraulic cylinders 21, 22, 23, 24 are extended and the auxiliary wheels 16, 17, 18, 19 lift and support the vehicle, the auxiliary wheel drive / turn switch 63 is operated to the "turn" position. 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, P12, Oil passages P8, P10 and P
And 11 respectively. Then, 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. The hydraulic oil is supplied to the hydraulic motor 25 from above in FIG.
5, the hydraulic oil is supplied to the hydraulic motor 26 from below in FIG.
Drives in reverse. Accordingly, the auxiliary wheels 16, 19 are rotated in reverse by the hydraulic motors 25, 26, so that the vehicle can turn right.

In each of the above embodiments, the left and right auxiliary front wheels 16, 17 and the auxiliary rear wheel 1 provided on the vehicle are provided.
8 and 19, the axles of which are the front wheels 12, 13 and the rear wheels 14, 1
5 was substantially perpendicular to the axle,
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. The support brackets 81 and 82 are hydraulic cylinders (not shown) for raising and lowering the auxiliary front wheels 16 and 17. The auxiliary front wheel 16 is mounted on a hydraulic motor 25 so as to be rotatable.
Connecting portions 83 and 84 are integrally formed on opposite sides of each of the support brackets 81 and 82, and the connecting portions 83 and 8 are integrally formed.
4 are connected by a connecting rod 85. An auxiliary wheel steering motor 86 is attached to a 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 an operating rod 88 is connected to an intermediate portion of the connecting rod 85, and the other end of the operating rod 88 is connected to a tip of a crank lever 87.

Normally, as shown in FIG. 5A, the auxiliary front wheels 16 and 17 can move the vehicle in the lateral direction by driving the hydraulic motor 25 in the same direction. it can. On the other hand, as shown in FIG. 5B, when the auxiliary rod steering motor 86 is driven to move the operating rod 88 downward through the crank lever 87 in the moving diagram,
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 are directed in different directions. Accordingly, the vehicle can be turned by driving the hydraulic motor 25 in this state.

In each of the above-described embodiments, in order to stop the vehicle moving by the auxiliary wheels 16, 17, 18, and 19, the steering force of the steered steering wheel 45 is returned to zero and the hydraulic motor is moved from the hydraulic cylinder 44 to the hydraulic motor 44. The operation was performed by stopping the supply of the hydraulic oil to the hydraulic wheels 25, 26 and stopping the driving of the hydraulic motors 25, 26. However, in consideration of safety, brakes and the like are applied to the auxiliary wheels 16, 17, 18, 19, respectively. It may be worn. In each of the above embodiments, the vehicle is provided with the four auxiliary wheels 16, 17, 18, and 19. However, the vehicle is provided between the front wheels 12, 13 and between the rear wheels 14, 15 to operate one by one. Alternatively, only one of them may be provided. Further, 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 apparatus of the present invention, the auxiliary wheels are provided at the lower part of the vehicle body, and the auxiliary wheels are supported by the lifting mechanism so as to be able to move up and down. The auxiliary wheels are supported rotatably by the drive motor, and the auxiliary wheels are supported on the vehicle body via the vehicle suspension. Therefore, the vehicle body lifted by the lifting mechanism rises together with the suspension, so that the lifting stroke of the lifting mechanism is small. It is possible to make the apparatus compact. In addition, the lifted vehicle body is supported by the auxiliary wheels on the road surface via the suspension, so that the suspension works when the vehicle runs on the auxiliary wheels in the same way as normal running, and the ride quality is impaired. There is no.

[Brief description of the 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 diagram showing another auxiliary wheel support structure in the auxiliary steering device of the present invention.

[Explanation of symbols]

 DESCRIPTION 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 / lowering valve 54 Auxiliary wheel driving valve 55 Auxiliary wheel driving direction switching valve 61 Control device 62 Auxiliary wheel lifting / lowering switch 63 Auxiliary wheel driving / turning switch

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Morita 5-33-8 Shiba, Minato-ku, Tokyo Inside Mitsubishi Motors Corporation (72) Inventor Tatsuya Kamata 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (72) Inventor Yasutaka Taniguchi 5-33-8 Shiba, Minato-ku, Tokyo Mitsubishi Motors Corporation (58) Field surveyed (Int. Cl. ⁶ , DB name) B60S 9 /twenty one

Claims (1)

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