JPH035205A - Tread controller for vehicle - Google Patents

Abstract

PURPOSE:To reduce the minimum turning radius of a vehicle by using oil supplied from the hydraulic cylinder of a power steering device through a tread control valve interlocking with a steering operation, driving a tread variable mechanism and increasing the tread. CONSTITUTION:A slider 7 supporting a wheel hub through a bearing is attached to the central boss part of a knuckle 1 supported by a vehicle body through a suspension mechanism so as to be slinding and displaceable in the direction of width of vehicle through a feed screw mechanism (tread variable mechanism) having a hydraulic actuator 9 as a driving source. In an oil passage connecting the direction control valve 54 of a power steering device and the right and left pressure chambers 53b, 53a of a power cylinder 53, a tread control valve 57 is interposed. Then, the tread control valve 57 is displaced in accordance with the quantity of the steering of a steering wheel 55 so as to control the communication of the pressure chamber of the low pressure side of the power cylinder 53 and the hydraulic actuator 9.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tread control device for a vehicle that changes the tread of the vehicle, that is, the distance between the left and right wheels.

(Prior Art) It has been known in the past that the steering stability of a vehicle can be further improved if the tread of a vehicle is set wider.

In addition, widening the tread makes it possible to increase the distance between the wheels and the chassis frame, which is located inside the wheels, making it possible to increase the maximum steering angle of the wheels without interfering with the chassis frame. It is also known that the radius can be reduced.

However, since the wheels must be positioned within the wheel house when the vehicle is traveling straight, unnecessarily widening the tread would also make the vehicle wider. It is generally done to set it fixedly. For this reason, conventionally, the maximum steering angle was determined by the fixedly set tread, and the minimum turning radius of the vehicle was determined by this maximum steering angle.

Further, as a device capable of overcoming such a situation, a device disclosed in Japanese Patent Application Laid-Open No. 61-22611 is known. In this conventional example, the mounting position of the suspension arm on the vehicle body side is displaced in the vehicle width direction according to the vehicle speed and steering angle, and when the steering angle is large, the suspension arm on the inner wheel side of the turn is displaced outward in the vehicle width direction. This is intended to increase the maximum steering angle of the wheels and reduce the minimum turning radius.

(Problem to be Solved by the Invention) However, the above-mentioned conventional example uses a dedicated oil pump as a hydraulic power source for operating the device, so it is particularly important for hydraulic devices such as power steering devices. When installed alongside an oil pump, there are problems in that it becomes difficult to secure installation space for the oil pump and that the power loss of the vehicle increases.

(Means for Solving the Problems) The present invention has been devised in view of the above-mentioned points, and includes variable tread laterals configured to be able to adjust the position of the wheels in the vehicle width direction with respect to the vehicle body, and hydraulic power steering. a device;
Hydraulic pressure is provided to operate the tread variable mechanism in a direction in which oil is supplied from a low-pressure side hydraulic chamber of a power cylinder of the power steering device and, when activated, displaces the wheels outward in the vehicle width direction. The actuator is interposed in an oil passage connecting the directional control valve of the power steering device and the left and right pressure chambers of the power cylinder, and is displaced in accordance with the amount of steering of the steering wheel to adjust the low pressure side pressure of the power cylinder. The tread control valve has a tread control valve that controls communication between the chamber and the hydraulic actuator, and the tread control valve communicates with the left and right output ports of the directional control valve and the left and right output ports of the power cylinder until the steering amount reaches a predetermined value. The pressure chamber of the power cylinder is communicated with the pressure chamber of the -F hydraulic actuator, and when the steering amount exceeds the predetermined value, the high pressure side output port of the directional control valve and the power While communication with the high-pressure side pressure chamber of the cylinder is maintained, communication between the low-pressure side output port of the directional control valve and the above-mentioned low-pressure side pressure chamber is cut off, and the low-pressure side pressure chamber is communicated with the above-mentioned hydraulic actuator. This is a vehicle tread control device characterized by:

(Function) According to the present invention, when the steering amount of the steering wheel exceeds a predetermined value, the tread control valve supplies oil discharged from the low-pressure side pressure chamber of the power steering device to the hydraulic actuator, thereby operating the hydraulic actuator. As a result, the hydraulic actuator operates the tread variable mechanism to displace the wheel outward in the vehicle width direction.

Therefore, when the steering angle is large, the gap between the wheels and the vehicle body in the vehicle width direction increases, and the maximum steering angle at which the wheels can be steered increases (7) and the minimum turning radius of the vehicle is reduced.

Further, since the power steering device is used as a hydraulic power source for operating the hydraulic actuator, there is no need for a dedicated hydraulic power source.

(Example) Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

As shown in FIG. 1, the knuckle 1 has a lower arm portion 1a supported by the outer end of the lower arm 3 via a ball joint 2, and a lower arm portion 1b attached to the lower end of the strut assembly 5 by bolts 4, 4. Fixed. The center of the ball joint is indicated by the symbol C, and the center of the vehicle body attachment portion of the lower arm 3 is indicated by the symbol B. Further, the upper end of the strut assembly 5 is supported by the vehicle body 6, so that the knuckle 1 is supported by the lower arm 3 and the strut assembly 5 so as to be able to swing up and down with respect to the vehicle body 6, and a king pin formed by ACa in the figure. It is supported so that it can rotate around an axis.

A center boss IC formed in a substantially cylindrical shape is provided in the center of the knuckle 1. A slider 7 formed in a substantially cylindrical shape is mounted on the inner circumferential side of the center boss portion 1c, and a spiral protrusion that is threaded onto the outer circumference of the slider 7 and the inner circumference of the center boss faB1c, respectively. is formed to constitute the feed screw mechanism 8. Therefore, when the slider 7 generates relative rotation with respect to the knuckle 1, this relative rotational displacement is caused by the action of the feed screw mechanism 8, causing the knuckle 1 to rotate.
This is converted into an axial displacement of the slider 7 relative to the displacement, and the slider 7 is displaced in the vehicle width direction. and,
The feed screw mechanism 8 is formed in such a direction that the slider 7 is displaced outward in the vehicle width direction when a hydraulic actuator 9, which will be described later, is extended from the illustrated state. Note that the center boss portion 1c of the knuckle 1.

The slider 7 and the feed screw mechanism 8 constitute a tread variable mechanism, and the feed screw mechanism 8 may be changed to a cam lead mechanism.

Further, on both ends of the outer periphery of the slider 7, there are annular flange-shaped stoppers that protrude in the outer radial direction. a, 7b are formed to prevent excessive displacement of the slider 7 due to interference with both ends of the center boss portion 1c of the knuckle l. moreover,
Annular slide bushes 10a and 10b are attached to both ends of the inner periphery of the center boss portion 1c of the knuckle 1, respectively, to smooth the relative displacement of the slider 1 with respect to the knuckle 1. Since these slide pushers 5lOa and 10b are arranged with a relatively wide span from each other, even when lateral force acting on the wheels or the upper and lower blades, which will be described later, are applied as moment force to the slider 7,
These forces can be efficiently received by the knuckles l. In addition, rubber bellows 1 each formed in a bellows shape are provided between the outer periphery of both ends of the center boss RIC of the knuckle l and the outer periphery of the stoppers 7a and 7b.
1a, . . llb are installed to prevent dust, muddy water, etc. from entering between the outer periphery of the slider 7 and the inner periphery of the center boss portion 1c of the knuckle 1.

Also, the stopper above? There is a fourth on the contact surface side of a and 7b.
As shown in the figure, a groove 40 is formed, and an elastic ring 41 made of rubber or resin is attached to this groove 40.

For this reason, the tapping noise and impact generated when the stoppers 7a and 7b are activated are suppressed. In this case, the structure may use an elastic ring 42 and a metal ring 43 as shown in FIG. 5 instead of the groove 40 and elastic ring 41 shown in FIG. 4, or the structure shown in FIG. Alternatively, a disc spring 44 may be used.

The outer housing of the bearing 12 is fitted onto the inner periphery of the slider 7, and the inner housing of the bearing 12 is fitted onto the outer periphery of the wheel hub 13. Therefore, the slider 7 rotatably supports the wheel hub 13 via the bearing 12. The drive shaft 14 is located in the center of the wheel hub I3.
The output end of the drive shirt 14 is fitted, and the wheel hub 13 receives driving force from the drive shirt 14 to rotate. A brake disc I5 of a disc brake device is fixed to an annular flange glB13a formed on the wheel hub 13 with bolts (not shown).
In addition, the wheel 17 of the wheel is connected to the hub bolt 16 and the wheel nut 17 which are implanted in this annular flange portion 13a.
is fixed to the wheel hub 13.

The hydraulic actuator 9 described above is provided between the upper end of the upper arm portion 1b of the knuckle 1 and the input portion 7c formed in a bulge on a part of the outer circumference of the inner end of the slider 7, and its expansion and contraction action causes the knuckle 1 and the slider to 7 to generate a relative rotational displacement. As shown in FIG. 2, this hydraulic actuator 9 has a cylindrical casing 9a whose upper end is connected to the upper arm part ib of the knuckle l via a ball joint 20 and which opens downward.
A piston 9b is slidably disposed within this casing 9a. The lower end of the piston rod 9c fixed to the piston 9b protrudes from the lower end of the casing 9a, and the lower end of this piston rod 9C is connected to the manpower section 7c of the slider 7 via a ball joint 21. has been done. Further, a spring 9d is disposed within the casing 9a between the lower part of the casing 9a and the surface of the piston 9b, and the piston 9b is biased toward the upper side of the casing 9a by the spring 9d. Therefore, the hydraulic actuator 9 is biased by the spring 9d in a direction in which the overall length is shortened. The upper chamber partitioned off by the piston 9b inside the casing 9a is composed of a hydraulic chamber 9e (2).

Therefore, when hydraulic pressure is introduced into this hydraulic chamber 9e from a hydraulic control device (described later) through a pipe 9'' shown in FIG. 1, the hydraulic actuator 9 expands against the biasing force of the spring 9d, When hydraulic pressure is not introduced into the hydraulic chamber 9e, the hydraulic actuators 5i-9 are kept in the shortest position by the spring 9d.

Furthermore, an accordion-shaped bellows 9g is provided between the outer periphery of the casing 9a and the lower end of the piston rod 9C to prevent dust, muddy water, etc. from entering into the casing 9a. Further, the inner chamber of the bellows 9g and the lower chamber in the casing 9a are communicated via a passage 9h,
Changes in volume of the lower chamber in the casing 9a due to expansion and contraction of the hydraulic actuator 9 are absorbed by the inner chamber of the bellows 9g. Note that 91 shown in FIG. 2 is a piston seal provided on the piston 9b.

The knuckle 1 has a knuckle arm ld extending toward the rear of the vehicle body, as shown in FIG. 2.3.

As shown in FIG. 3, the upper end of an auxiliary link 24 is pivotally supported at the tip of the knuckle arm 1d via a pivot shaft 22 that is inclined forward by an angle θ with respect to the vehicle width direction in a horizontal plane. . The outer end of the tie rod 23, which is displaced in the vehicle width direction in response to a steering device (not shown), is connected to the lower end of the auxiliary link 24 via a ball joint 25. Further, a holding portion 7d is formed in a bulging manner below the manpower portion 7c on the outer circumference of the inner end of the slider 7, and both ends of the control arm 26 are pivotally connected to the holding portion 7d of the slider 7 and the case of the ball joint 25. has been done. This control arm 26 controls the longitudinal position of the ball joint 25 by controlling the deflection angle of the auxiliary link 24 in the longitudinal direction according to the relative rotational displacement of the slider 7 with respect to the knuckle. This is to variably control R. The reference numerals shown in FIGS. 2 and 3 indicate the center position of the ball joint 25. Also, knuckle arm ld.

Support shaft 22. Auxiliary link 24. The ball joint 25 and the control arm 26 constitute a knuckle arm length variable mechanism.

The caliper 30 of the disc brake device is attached to the knuckle 1 at a position opposite to the above-mentioned hydraulic actuator 9 and knuckle arm ld (on the front side of the vehicle body) with respect to the center of the axle. This caliper 30 has knuckle 1
a support bracket 31 that is fixed to and located inside the brake disc 15; and two fixed bins that are screwed onto a protruding boss portion 31a formed on the outer peripheral edge of the support bracket 31 and protrude outward in the vehicle width direction. 32.32, a caliper body 33 slidably attached to these two fixed bins 32.32, and a brake pad 3 attached between the caliper body 33 and the brake disc 15.
4.34.

Therefore, the caliper body 33 follows the displacement of the brake disc 15 in the vehicle width direction caused by the relative displacement of the slider 7 with respect to the knuckle 1 by sliding displacement with respect to the fixed bins 32 and 32. . Further, an accordion-shaped bellows 35 connected to the caliper body 33 and the support bracket 31 is provided around the fixed bin 32.32, and the sliding part between the caliper body 33 and the fixed bin 32.32 is covered with dust and dirt. It is designed to prevent the intrusion of people such as

FIG. 7 is a hydraulic circuit diagram showing the aforementioned hydraulic control device that controls the operation of the hydraulic actuator 9. As shown in FIG.

This hydraulic control device controls the supply of hydraulic pressure to the hydraulic actuator 9 using the hydraulic pressure of a power steering device which is known per se. That is, in Figure 7, 5
0 is a reservoir tank that stores oil, 51 is an oil pump that sucks in oil in the reservoir tank and discharges it, 5
Reference numeral 3 denotes a power steering hydraulic cylinder that operates in response to hydraulic pressure supplied from the oil pump side and generates steering assist force, and 54 a directional control that controls the hydraulic pressure acting on the hydraulic cylinder 53 in accordance with the operating state of the steering wheel 55. The valve 56 is a rack and pinion type steering gear box, and these members 50 to 56 are all known. A tread control valve 57 for controlling the supply of hydraulic pressure to the hydraulic actuator 9 connects the left and right output ports of the direction control valve 54 for power steering and the left and right hydraulic chambers of the hydraulic cylinder 53. 59 is interposed. The tread control valve 57 is constituted by a 6-port valve, and communicates the left and right output ports of the direction control valve 54 with the left and right hydraulic chambers of the hydraulic cylinder 53 in a neutral state, and connects the hydraulic chamber 9e of the hydraulic actuator 9 to a reservoir tank. 5
0. Further, the tread control valve 57 is connected to the steering rod 60 and is displaced following the steering operation, so that even if the displacement following the steering rod 60 occurs, the high oil pressure of the direction control valve 54 is not maintained. Communication is always maintained between the output port and the hydraulic chamber to which high hydraulic pressure of the hydraulic cylinder 53 is supplied, but when the steering angle of the steering wheel reaches a predetermined amount, the port of the direction control valve 54 and the hydraulic cylinder enter a low pressure state. 53, the communication with the hydraulic chamber which is in a low pressure state is cut off,
Thereafter, the oil discharged from the hydraulic chamber of the hydraulic cylinder 53 as the steering angle changes is supplied to the hydraulic actuator 9. Note that the oil passage connecting the tread control valve 57 and the hydraulic actuator 9 is the relief valve 6.
1 to the reservoir tank 50, and this relief valve 61 opens the hydraulic chamber 9 of the hydraulic actuator 9.
This prevents the hydraulic pressure acting on e from becoming too high. In addition, the hydraulic chamber 9e of the hydraulic actuator 9 is also connected to the reservoir tank 50 via a check valve 62. This check valve 62 is connected to the reservoir tank 50.
This allows oil to flow only from the side to the hydraulic actuator 9 side, and prevents the pressure in the hydraulic chamber 9e of the hydraulic actuator 9 from becoming negative pressure.

The operation of the above embodiment will be explained below.

First, consider the case where the steering wheel 55 is steered to the left in the hydraulic control system shown in FIG.
High oil pressure is output from the left output capo L of the direction control valve 54, and this oil pressure is introduced into the right pressure chamber 53b of the hydraulic cylinder 53 via the oil passage 59, so that the steering rod 60
is displaced to the left in FIG. 7, and the left and right wheels are steered to the left. Since the displacement of the tread control valve 57 is small when the steering angle is smaller than the predetermined amount, the hydraulic cylinder 53
The oil discharged from the left pressure chamber 53a is returned to the reservoir tank 50 via the oil passage 58 and the control valve 54. In this state, the hydraulic actuator 9 is connected to the ribbon tank 50, so the hydraulic actuator 9 is in the shortest state and the tread does not change. Furthermore, when the steering angle becomes larger than a predetermined amount, the tread control valve 57, which follows the displacement of the steering rod 60, is displaced to the left in FIG. Although communication with chamber 53a is cut off,
Since communication between the left output port L and the right pressure chamber 53b is maintained, operation of the power steering device is ensured.

In this state, the left pressure chamber 53 of the hydraulic cylinder 53
Since the point a communicates with the hydraulic chamber 9e of the hydraulic actuator 9, oil discharged from the hydraulic cylinder 53 with the steering operation is introduced into the hydraulic actuator 9, and the hydraulic actuator 9 is extended. Note that when the steering wheel 55 is turned back to the neutral direction from this state, the hydraulic actuator 9 is connected to the reservoir tank 50 when the steering angle becomes smaller than a predetermined amount, so the hydraulic actuator 9 is shortened by the biasing force of the subung 9d. be done.

Also, contrary to the above, the steering wheel 55 is steered to the right. In this case, the hydraulic actuator 9 operates in the same manner as in the above case.

Next, the operation of the apparatus shown in FIGS. 1 to 3 will be explained in detail. When the hydraulic pressure output from the above hydraulic control device is introduced into the hydraulic chamber 9c of the hydraulic actuator 9 from the piping 9f shown in FIG. Displaced downward in Figure 2,
Actuator 9 extends. As a result, slider 7
is rotationally displaced relative to knuckle l in the clockwise direction in FIG. It is displaced to the left in Figure 1 (outward in the vehicle width direction). At this time, since slide bushes 10a and 10b are provided between the slider 7 and the knuckle 1,
The slider 7 is smoothly displaced with respect to the knuckle 1. A wheel hub 13 is supported by the slider 7 via a bearing 12, and a rotor 15 is fixed to the wheel hub 13. The wheel 18 also follows the slider 7 and is displaced outward in the vehicle width direction. Therefore, the tire 19 mounted on the wheel 18 is also displaced outward in the vehicle width direction,
The vehicle's tread will be widened. Note that since the wheel hub 13 is rotatably supported by the slider 7 via the bearing 12, the wheel hub 13, brake disc 15, etc. are rotated as the slider 7 is rotated. wheel 18
．． The tire 19 does not rotate. Also, since the caliper body 33 also slides following the displacement of the brake disc in the vehicle width direction, the operation of the brake is not hindered.

Incidentally, since the displacement of the slider 7 described above is also transmitted to the ball joint 25 via the control arm 26, the ball joint 25 attached to the outer end of the tie rod 23 moves around the pivot shaft 22 at the second position. .3 Oscillating displacement to the left in Figure 3. Therefore, the actual knuckle arm length R, which varies depending on the position of the center point of the ball joint 25, becomes shorter. Since the hydraulic actuator 9 is extended during steering as described above, the knuckle arm length R is shortened, thereby increasing the steering angle generated at the wheels.

This operation will be explained in more detail based on FIG. In FIG. 8, the broken line shows the steering state using a general conventional device, the dashed line shows the steering state when only the tread is increased, and the solid line shows the steering state according to this embodiment. In the conventional device shown by the broken line, the maximum steering angle of the wheel is determined by the gap SO with the vehicle body 6, and in this case, the connection point between the tie rod and the knuckle arm is determined by DOl or the actual knuckle arm length. In addition, when performing only the tread control shown by the - dotted chain line, DORO does not change, but the tread increases in ΔT on one side compared to the conventional example shown by the broken line. Therefore, the gap with the vehicle body 6 increases to S2, which is larger than Sl, and the steering angle of the wheels can be increased by the increased gap with the vehicle body 6.And, In this example shown by the solid line,
As described above, as the tread increases, the control arm 26 moves the ball joint 25 closer to the center of the knuckle, so the actual length of the knuckle arm becomes shorter than RO, as shown by R2 in the figure. At this time, since the lateral position of the Quirod 23 is determined by the amount of steering of the steering wheel, the steering angle of the axle increases as the length of the knuckle arm becomes shorter. and,
The gap between the wheels and the vehicle body 6 is comparable to that of the conventional example shown by the broken line, and by increasing the steering angle, problems such as interference between the wheels and the vehicle body do not occur. Note that the center position of the ball joint 25 in this case is illustrated by D2. Also,
The set angle θ of the pivot shaft 22 shown in FIG. 3 is set so that the control arm 26 can smoothly and efficiently displace the ball joint 25 without interfering with the displacement of the tie rod. In addition, the reference numerals in FIG. 8 indicate the center of rotation of the knuckle 1.

In addition, in FIG. 8 above, the operation of the wheels on the inner side of the turning wheel has been explained, but also for the wheels on the outer side of the turning side (not shown), the actual length of the knuckle arm decreases as the tread increases. As the steering angle increases, it should be easily understood that even if the steering angle increases, the clearance with the vehicle body is ensured by increasing the tread.

According to the above embodiment, the tread widens when the steering angle is large and the maximum steering angle of the wheels increases, so the minimum turning radius of the vehicle can be reduced without increasing the vehicle width, and the tires protrude from the fender when driving straight. It has many advantages. Furthermore, since the steering angle of the wheels can be increased without interfering with the vehicle body, particularly on the inner turning wheel side and the outer turning wheel side, the minimum turning radius of the vehicle body can be reduced very efficiently.

Note that if there is no need to reduce the turning radius, the ride comfort of the vehicle can be improved by extending the wheelbase by the increase in the maximum steering angle.

Effects regarding the detailed structure of the above embodiment are listed below.

First, a feed screw mechanism is provided between the knuckle l and the slider 7 to displace the wheel in the vehicle width direction and control the tread, so even if a lateral force is applied to the wheel when the vehicle turns, it will not be adjusted. The tread is reliably held, and this lateral force is not directly applied to the actuator, resulting in excellent reliability and durability.

In addition, since the knuckle 1 is provided with a configuration for making the tread variable, suspension alignment such as camber and caster does not change when the tread is changed, and stable steering stability can be ensured. The advantage is that the existing suspension arms can be used as they are.

Furthermore, since the slide bushes 10a and 10b are provided at intervals between the knuckle 1 and the slider 7, it is possible to save space and smooth the displacement of the slider 7, and at the same time reduce the lateral force applied to the tire. This has the effect of being able to efficiently receive the moment generated by.

In addition, stoppers 7a and 7b are provided to restrict the sliding displacement between the knuckle 1 and the slider 7, so safety is excellent.Also, since a buffer member is placed on the stopper, there is no inconvenience such as impact noise, making it practical. It has excellent advantages.

In addition, the caliper body 33 is slidably supported by a fixing pin 32 that protrudes outward in the vehicle width direction from the support bracket, and a sufficient insertion depth of the fixing pin 32 into the caliper body 33 can be ensured. There is an advantage that an excessive bending moment does not act on the fixing pin 32 when the tread is small (when traveling straight or when the steering angle is small), and the caliper body 33 can efficiently follow changes in the tread.

In addition, since the hydraulic actuator 9 is placed on the opposite side of the axle from the brake carrier, the dead space is effectively utilized, resulting in excellent space efficiency, and since the spring 9d is placed inside the hydraulic actuator 9, Even if the hydraulic pressure supply device fails, the tread can be kept small, providing excellent safety.

Furthermore, by providing the auxiliary link 24 and the control arm 26, when the tread increases, the ball joint at the outer end of the tie rod is displaced and the knuckle arm length is shortened. The steering angle of the wheels is efficiently increased, the turning radius is reduced, and the maneuverability of the vehicle is improved.

In addition, since the hydraulic actuator 9 is operated using the oil discharged from the hydraulic cylinder of the power steering device by the tread control valve 57 that is linked to the steering operation, a special pressure source is not required. It has excellent energy efficiency and space utility, has a simple structure, and has the effect of reliably increasing the tread at a large steering angle.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and as a tread variable mechanism, the conventional example JP-A-64-226
A material similar to that shown in Publication No. 11 may be used.

Moreover, it goes without saying that various other modifications can be made without departing from the gist of the present invention.

(Effects of the Invention) Hereinafter, a detailed explanation will be given along with examples (7).According to the present invention, the oil discharged from the hydraulic cylinder of the power steering device is controlled by the tread control valve linked to the steering operation h3. Since the hydraulic actuator is operated to increase the tread when the vehicle is in use, there is no need for a special pressure source, the structure is simple, and the tread is increased reliably at large steering angles to increase the vehicle's tread. The present invention has the effect of providing a vehicle tread control device with a simple structure and low cost, which can reduce the diameter of the minimum turning of the vehicle and has excellent energy efficiency and space utility.

[Brief explanation of drawings]

Fig. 1 is a rear view showing one embodiment of the present invention, and Fig. 2 is a rear view showing an embodiment of the present invention.
Figure 3 is a side view in the direction of the ■ arrow in Figure 1, Figure 4 is an enlarged view of the main part of Figure 1, and Figures 5 and 6 are modifications of the configuration in Figure 4. FIG. 7 is a diagram corresponding to FIG. 4, FIG. 7 is a schematic diagram of the hydraulic control device, and FIG. 8 is an explanatory diagram of the operation. 1...knuckle, ld...knuckle arm. 7...Slider, 8...Feed screw mechanism. 9...Hydraulic actuator, 23...Tie rod. 24... Auxiliary link, 25... Ball joint 2
6...Control arm. 30...brake caliper, 53...power cylinder. 54... Directional control valve. 57...Tread control valve. 60...Steering rod

Claims (1)

[Claims] It operates by supplying oil discharged from the low-pressure side hydraulic chamber of the power cylinder of the power steering device, a hydraulic power steering device, and a tread variable mechanism configured to be able to adjust the position of the wheels in the vehicle width direction relative to the vehicle body. A hydraulic actuator is provided to operate the tread variable mechanism in a direction that displaces the wheel outward in the vehicle width direction when the actuator is actuated, a directional control valve of the power steering device, and left and right pressure chambers of the power cylinder. A tread control valve is disposed in the connecting oil passage and is displaced according to the amount of steering of the steering wheel to control communication between the low pressure side pressure chamber of the power cylinder and the hydraulic actuator, and the tread control valve is disposed in the oil passage. The valve communicates between the left and right output ports of the directional control valve and the left and right pressure chambers of the power cylinder, and also connects the pressure chamber of the power cylinder with the hydraulic actuator until the steering amount reaches a predetermined value. When the steering amount exceeds the predetermined value, communication is maintained between the high pressure side output port of the directional control valve and the high pressure side pressure chamber of the power cylinder, while the low pressure side output port of the directional control valve and the high pressure side pressure chamber of the power cylinder are maintained in communication. A tread control device for a vehicle, characterized in that the communication with the low pressure side pressure chamber is cut off, and the low pressure side pressure chamber is configured to communicate with the hydraulic actuator.