JPS61193912A - Suspension for vehicle - Google Patents

Abstract

PURPOSE:To incline the chassis with correspondence to the steering amount thus to achieve similar steering feeling with two wheeler by providing a control valve for coupling one side of cylinder chamber selectively to the fluid supply side of hydraulic circuit while the other to the fluid discharge side. CONSTITUTION:The right and left suspension springs 14 are provided at the upper section with a hydraulic telescopable member 24 comprised of a piston 22 and a cylinder 23 the upper end of which is fixed to the chassis 2 while the lower end to the intermediate section of lower arm 4. Then pressure oil is fed into the upper cylinder chamber 23a of cylinder 23 and discharged from the lower cylinder chamber 23b to regulate the overall length of the spring 14. Supply/discharge of working oil against said cylinder 23 is controlled through a control valve 26 responsive to a slide shaft 13 to vary the overall length to incline the chassis quickly and smoothly with correspondence to the turning operation.

Description

[Detailed Description of the Invention] The present invention is applicable to the Ll Dotachi Denkou (left and right), like a four-wheeled motor vehicle or a three-wheeled motor vehicle.
This invention relates to a suspension device for a vehicle that includes at least one pair of wheels.

In a vehicle equipped with a pair of left and right wheels, the body tends to tilt outward due to centrifugal force when turning, but on the other hand, in a two-wheeled vehicle, the body tends to tilt inward, i.e. Turning is performed in a lean state. The present invention aims to provide a suspension device that allows a four-wheeled vehicle or a three-wheeled vehicle to experience the same steering sensation as a two-wheeled vehicle by leaning the vehicle body when turning.

A tricycle whose body can be tilted inward, that is, toward the direction of the turn when turning, is disclosed in, for example, Japanese Patent Laid-Open No. 5
As described in Publication No. 4-25033, this tricycle has two front wheels on the left and right and one rear wheel, and when turning, the driver moves the center of gravity toward the direction of the turn against centrifugal force. By moving the wheel, the vehicle body is tilted in the turning direction.

The above-mentioned tricycle is a straddle type similar to a regular motorcycle,
It is relatively easy to tilt the car body by moving the center of gravity as described above, but if the driver's seat is a seat like a normal car, the car body can be tilted by moving the driver's center of gravity. It is not always easy to tilt.

Therefore, the present invention provides above &l! Regardless of whether it is a straddle type or a seat type, the purpose is to allow the vehicle body to tilt when turning without the driver having to consciously shift the center of gravity.

Therefore, in the present invention, the suspension spring is integrally provided with an extensible member that is made up of a piston and a cylinder and expands and contracts by fluid pressure, and the piston selectively controls one of the two cylinder chambers defined within the cylinder. A control valve is provided which is connected to the fluid supply side of the fluid pressure circuit and connects the other cylinder chamber to the fluid discharge side of the circuit, and the control valve is operated in response to the steering mechanism to control the suspension spring according to the steering amount. Change the overall length of the car to tilt the car body.

According to the present invention, regardless of whether it is a straddle type or a seat type,
Even if the driver does not consciously shift the center of gravity when turning, the vehicle body automatically tilts in the direction of the turn by steering the vehicle, providing a steering feel similar to that of a two-wheeled vehicle.

Support 11 The illustrated embodiment in which the present invention is applied to a three-wheeled motor vehicle with two front wheels and one rear wheel will be described below.

FIG. 1 is a front view of the suspension device when the vehicle is traveling straight, and FIG. 2 is a front view of the suspension device when turning to the right, and the hydraulic system is not shown. Note that in the following description, right or left refers to right or left as seen from the driver.

1 is the front wheel and 2 is the vehicle body. A knuckle 3 is provided on each of the left and right front wheels 1.1 integrally with the axle, and a lower arm 4 is connected to the lower end of each of these knuckles 3 via a ball joint 5. An upper arm 6 is connected via a ball joint 7.

The other end of the lower arm 4 is pivotally connected to the vehicle body 2 via a bracket 8, and the other end of the upper arm 6 is attached to a bracket 9.
It is pivotally connected to the vehicle body 2 via a so-called Witschbon suspension.

A knuckle arm 10 is provided on the knuckle 3 and projects diagonally rearward. A tie rod 12 is connected to this knuckle arm 10 via a ball joint 11, and the other end of the tie rod 12 is connected to the end of a slide shaft 13. It is pivoted to. The slide shaft 13 is slidably supported by the vehicle body 2 by a bearing 21. Slide shaft 1
A rack 17 is provided in the center of the steering shaft 19, and a binion 18 provided on the steering shaft 19 is attached to the rack 1.
It meshes with 7. 20 is a steering wheel.

The left and right suspension springs 14, 14 each have a hydraulically actuated telescoping member 24 consisting of a piston 22 and a cylinder 23 at the top, and the upper end of the telescoping member 24 is pivotally connected to the vehicle body 2 via a bracket 15, and the suspension The lower end of the spring 14 is attached to the intermediate portion of the lower arm 4 via a pivot 16.

When the vehicle is traveling straight, the pinion 18 meshes with the rack 11 at its center position as shown in FIG.
is rotated counterclockwise in the figure as shown by arrow a in FIG. Then, due to the rotation of the pinion 18, the slide shaft 13 moves to the left as indicated by the arrow, thereby deflecting the front wheel 1 to the right. At this time, as shown in Figure 3 and below,
As will be detailed later, pressure oil is supplied to the upper cylinder chamber 23a of the cylinder 23 of the suspension spring 14 on the left side (right side in the figure), and the lower cylinder chamber 23b is supplied with pressure oil.
Hydraulic oil is discharged from the upper cylinder chamber 23a of the right suspension spring 14, and pressure oil is supplied to the lower cylinder chamber 23b. The coil spring 25 of the suspension spring 14 is very rigid, but in reality it hardly expands or contracts, so the left cylinder 23 moves upwards due to the hydraulic pressure acting between it and the piston 22, that is, the extensible member 24 extends), and the suspension The overall length of the spring 14 becomes longer. On the other hand, in the right suspension spring 14, the cylinder 23 moves downward, that is, the telescopic member 24 contracts, and the overall length becomes shorter.

As described above, this operation is performed quickly and smoothly because the hydraulic oil is simultaneously supplied and discharged to both cylinder chambers 23a and 23b facing each other with the piston 22 in between.

As a result, the left suspension spring 14 pushes the lower arm 4 downward relative to the vehicle body 2, and the right suspension spring 14 pushes the right lower arm 4 downward relative to the vehicle body 2.
increase relative to At this time, each upper arm 6 follows the movement of each lower arm 4. However, since the front wheels 1 are always in contact with the ground, when each member moves as described above, the vehicle body 2 eventually tilts to the right, that is, toward the turning direction, as shown in FIG. also tilts)
, the vehicle turns in a lean state similar to that of a motorcycle.

Although the case of turning to the right has been described above, the same applies to the case of turning to the left.

FIG. 3 shows a hydraulic system for supplying and discharging hydraulic oil to the cylinder 23 as described above during turning. The supply of hydraulic oil to the cylinder 23 and the discharge of hydraulic oil from the cylinder 23 are as follows:
It is controlled by a control valve or rotary valve 26 which responds to the slide shaft 13, and this rotary valve 26 is supplied with hydraulic oil pressurized by a pump 27. The pump 21 is driven by the engine of the vehicle, and when the engine starts, the hydraulic oil in the reservoir tank 28 is sent by the pump 21 to the supply pipe 31 via the cut-off valve 29 and the one-way valve 30, and reaches the rotary valve 26. A part of the pressure is sent to the accumulator 32 and accumulated therein. and supply pipe 31
When the internal pressure reaches the specified value, the piston 33 of the cut-off valve 29 moves to the right in the figure against the spring 34, cutting off the supply pipe 31 from the pump 27 and draining the oil discharged from the pump 27. It is circulated through the bypass pipe 35 to the suction side. The one-way valve 30a provided in the supply pipe 31 is designed to reduce the pressure generated on the suspension side by 7.
This prevents the water from escaping to the cumulator 32.

As shown in FIGS. 4 to 7, the rotary valve 26 includes a cylindrical inner valve 36 and a cylindrical outer valve 3 that is fitted in contact with the outer peripheral surface of the inner valve 36 so as to be relatively rotatable.
7 and a main body 38 that rotatably accommodates and supports these.The inner valve 36 has an oil supply passage 40 that communicates with the supply pipe 31 through an inlet 39, and a return pipe 42 (see Fig. 3) through an outlet 41. (see) is provided. The oil supply passage 40 and the oil discharge passage 43 are provided along the central axis of the inner valve 36 and are open at both end faces of the inner valve 36, respectively. The inner valve 36 is also provided with two oil supply boats 44a and 44b extending radially from the oil supply passage 40 and opening on the outer peripheral surface in the same cross section, and a similar oil drainage boat on the oil drainage passage 43 side. 45a 145b
is provided. These refueling boats, as shown in FIGS. 5 to 7, are arranged so that the angle formed by the refueling boat 44a and the oil draining boat 45a is equal to the angle formed by the refueling boat 44b and the oil draining boat 45b. It is located in

The outer valve 37 includes - the refueling boat 44, respectively;
For example, the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can communicate with the oil supply holes 46a and 46b that can be communicated with
The oil drain hole 47b is provided in an angular relationship such that when the oil drain hole 47b communicates with the oil drain boat 45b, when the oil drain hole 47b communicates with the oil drain boat 45b. The main body 38 has the oil supply and drainage holes 46a and 47.
an oil passage 48a that communicates with the oil supply and drainage hole 46b;
, 47b are provided, and the oil passage 48a communicates with the upper cylinder chamber 23 of the cylinder 23.
a, and the oil passage 48b is connected to the lower cylinder chamber 23b of the cylinder 23 (see FIG. 3).

As shown in FIGS. 3 to 5, the outer valve 37 is connected to the piston 22 side of the telescoping member 24 via a lever piece 50 that extends through a circumferential groove 49 formed in the main body 38. The pistons 22 are connected to each other and rotate according to the movement of the piston 22. Further, the inner valve 36 is connected to the slide shaft 13 via a similar lever piece 51,
It rotates in accordance with the movement of the slide shaft 13, that is, the steering operation. The return pipe 42 connected to the outlet 41 of the rotary pal 126 is connected to the reservoir tank 28, as shown in FIG.
A safety valve 52 is provided between the two. Piston 22
A damper 53 is built inside.

When the vehicle is traveling straight, the rotary valve 26 is in the neutral position as shown in FIG. Not communicating. From this state, in response to the steering operation, the inner valve 36 is moved to the slide shaft 1.
3. When the lever piece 51 is rotated, for example, counterclockwise, the oil supply hole 46a opens as shown in FIGS. 4 and 5.
is aligned with the refueling boat 44a, and the oil drain hole 47b
is aligned with the oil drain boat 45b, and as a result, the upper cylinder chamber 23a of the cylinder 23 is connected to the oil passage 48a and the oil supply hole 4.
The lower cylinder chamber 23b communicates with the return pipe 42 through the oil passage 48b1, the floating oil hole 47b1, the oil drain boat 45b, the oil drain passage 43, and the outlet 41. . Then, the telescopic member 24 consisting of the cylinder 23 and the piston 22 expands, but at this time, in accordance with the movement of the piston 22, the outer valve 37 rotates counterclockwise via the lever piece 50, and rotates in the same direction. This follows the inner valve 36 that continues to rotate, so while the inner valve 36 is rotating, the oil supply/drainage holes 46a, 47b and the oil supply/drainage boat 44a,
45b continues, and the telescoping member 24 and therefore the suspension spring 14 continue to expand. When the rotation of the inner valve 31 stops, the suspension spring 14 is out of alignment, and the oil supply/drainage holes 46a, 47 are removed.
The suspension spring 14 stops extending when it assumes the neutral position again, and the suspension spring 14 extends by a length corresponding to the steering angle. On the other hand, in the rotary valve 26 on the other side, since the inner valve 36 rotates clockwise in FIG. 6, the refueling boat 44b is aligned with the refueling hole 461), and the oil draining boat 45a is aligned with the refueling hole 461) as shown in FIG. is the oil drain hole 47a
Consistent with As a result, the upper cylinder chamber 23a of the cylinder 23 communicates with the return pipe 42, the lower cylinder chamber 23b communicates with the supply pipe 31, and the suspension spring 14 is shortened by a length corresponding to the steering amount.

In this way, turning is performed with the vehicle body 2 tilted in the turning direction as described with reference to FIG. The vehicle body tilts quickly and smoothly in response to steering operations.

As described above, in the present invention, in a suspension device provided between a pair of left and right wheels of a vehicle and a vehicle body, an elastic member consisting of a piston and a cylinder and expanding and contracting by fluid pressure is integrally attached to a suspension spring. control for selectively connecting one of both cylinder chambers defined in the cylinder by the piston to the fluid supply side of the fluid pressure circuit and connecting the other cylinder chamber to the fluid discharge side of the circuit; A valve is provided, and by making the control valve act in response to the steering mechanism, the overall length of the suspension spring is changed according to the amount of steering and the vehicle body is tilted, so that when the vehicle is turning, the vehicle body can be quickly moved in response to the turning operation. The vehicle tilts smoothly and smoothly, providing a handling sensation similar to that of a motorcycle.

[Brief explanation of drawings]

FIGS. 1 and 2 are front views of the suspension device according to the present invention when the vehicle is traveling straight and when turning, respectively, and the hydraulic system is not shown. Fig. 3 is a drawing showing the hydraulic circuit and suspension spring when traveling straight, Fig. 4 is a vertical cross-sectional view of the control valve when the suspension spring is extended, and Fig. 5 is a diagram showing V-V in Fig. 4.
6 and 7 are sectional views taken along line a, similar to FIG. 5, showing the states of the control valve when the vehicle is traveling straight and when the suspension spring is shortened, respectively. 1... Front wheel, 2... Vehicle body, 3... Knuckle, 4...
...Lower arm, 5...Ball joint, 6...
Upper arm, 7...Ball joint, 8...
Bracket, 9... Bracket, 10... Knuckle arm, 11... Ball joint, 12... Tie rod, 13... Slide shaft, 14... Suspense John spring, 15... Blanket, 1
6... Pivot, 17... Rack, 18... Pinion, 19... Steering shaft, 20... Steering wheel, 21... Bearing, 22... Piston, 23... Cylinder, 24... Telescopic member, 25
...Coil spring, 26...Rotary valve (
control valve), 27... pump, 28... reservoir tank, 29... cut-off valve, 30... one-way valve, 31... supply pipe, 32... accumulator, 33... piston , 34... spring, 35
...Bypass pipe, 36...Inner valve, 37...
・Outer valve, 38...Main body, 39...Inlet, 4
0... Oil supply path, 41... Outlet, 42... Return pipe,
43...Oil drain path, 44...Refueling boat, 45...
Oil drain boat, 46... Oil supply hole, 47... Oil drain hole, 4
8...Oil passage, 49...Groove, 50...Lever piece, 51...Lever piece, 52...Safety valve, 53...
・Damper device.

Claims (1)

[Claims] In a suspension device provided between a pair of left and right wheels of a vehicle and a vehicle body, a suspension spring is integrally provided with an extensible member consisting of a piston and a cylinder and expands and contracts by fluid pressure, and a section is formed in the cylinder by the piston. A control valve is provided for selectively connecting one of the two cylinder chambers to the fluid supply side of the fluid pressure circuit and the other cylinder chamber to the fluid discharge side of the circuit, and the control valve is responsive to the steering mechanism. A suspension device for a vehicle, characterized in that the overall length of the suspension spring is changed according to the amount of steering to tilt the vehicle body.