JPS6015213A - Suspender - Google Patents

Abstract

PURPOSE:To prevent the biased abrasion of a tire as well as raise the turning and running performance of a vehicle by providing a controller to alter a camber according to acceleration. CONSTITUTION:In a control unit 34, the direction D and magnitude Q of acceleration (a) is calculated from output signals of an acceleration sensor 36, and control signals corresponding to the direction D and magnitude Q are sent out to amplifiers 37F and 37R by which electric current is supplied to servo valves 26F and 26R. Working fluid is supplied to each actuator 28 by which the cambers of each wheel 12 are altered. In short, by the actuator 28, left and right- handed wheels 12 are inclined toward the direction C heading for the turning center, the vehicular camber of the wheels 12 is changed to a value corresponding to acceleration, and the deformation of the tire is prevented.

Description

[Detailed Description of the Invention] (Technical Field) This invention relates to a suspension system, and more specifically, a suspension system that changes the camber of a wheel in accordance with the acceleration in the vehicle width direction and improves running stability when the vehicle turns. Regarding equipment.

(Background Art) A suspension system supports wheels in a predetermined angular relationship (wheel alignment) with a vehicle body. As is well known, wheel alignment is a general term for kingpin offset, kingpin extension, trail, caster, toe-in, and camber, each of which has a significant relationship with vehicle maneuverability and running stability. .

In particular, camber (the angle that the center of the wheel makes with the vertical plane when viewed from the front of the vehicle) is a cause of generating lateral force (canvas thrust) that acts in the direction in which the wheel is tilted corresponding to the size of the camber. This has a large impact on driving performance when turning.

By the way, if the vehicle body rolls when the vehicle is turning, as shown in Figure 7, the wheels tilt together with the vehicle body in the direction opposite to the center of the turn (vehicle width direction) due to centrifugal force, and the ground camber changes. It has characteristics. Furthermore, since the suspension system has a predetermined geometric configuration (geometry) and is attached to the vehicle body using an elastic body, when force is applied during turning, etc., the wheel alignment changes according to the geometry, and the camber also changes. It has the characteristic of changing.

Such camber changes due to body roll or camber changes according to the geometry when the vehicle is cornering cause uneven tire wear, and the camber last usually acts in a direction that reduces cornering force. This has the disadvantage that it may cause the vehicle to spin, drift, etc., and may impede stability.

(Object of the Invention) This invention was made in view of the above-mentioned drawbacks, and it counteracts the centrifugal force of the vehicle by forcibly tilting the wheels toward the center of the turn when the vehicle is turning. The object of the present invention is to obtain a camber that generates canvas thrust that acts toward the turning center of the vehicle, thereby improving the turning performance of the vehicle and preventing uneven tire wear.

(Structure of the Invention) A suspension system according to the present invention includes an acceleration detection means for detecting acceleration of a vehicle in the vehicle width direction, a drive means capable of changing the camber of a wheel, and a drive means for driving the vehicle based on an output signal of the acceleration detection means. and control means for controlling the means and changing the camber in response to acceleration.

According to this suspension system, a camber corresponding to the acceleration in the width direction of the vehicle when turning is forcibly set, thereby preventing uneven tire wear and reducing canvas last that acts in the opposite direction to the cornering force. This can improve running stability when the vehicle is turning.

(Example) Embodiments of the present invention will be described below based on the drawings.

1 to 7 are diagrams showing one embodiment of the present invention.

First, to explain the configuration, Fig. 1 is a diagram showing the main components of the entire suspension system according to the present invention, Fig. 2 is a sectional view showing the front wheel suspension system, and Fig. 3 is a sectional view showing the rear wheel suspension system. , which is applied to front-wheel drive vehicles.

In Fig. 1, 11 is an on-vehicle engine, 12FR is a right front wheel, 12FL is a left front wheel, 12RR is a right rear wheel, 12
RL indicates the left rear wheel, and these wheels (hereinafter represented by the number 12 without a subscript) are attached to the vehicle body as shown in FIGS. 2 and 3. That is, as shown in FIG. 2, in the front wheel +2FR112FL, a road wheel 12b supporting a tire a on its outer periphery is attached to a hub 13 by a bolt 14. The hub 13 is rotatably supported by a knuckle 15 and connected to the engine 11 via a drive shaft 6. The knuckle 15 has a lower end connected to the transverse link 1 via a ball joint 17, and an upper end supported by a vehicle body (not shown) via a shock absorber 19 and a spring 20. That is, the knuckle 15 is attached to a bracket 19a fixed to the lower end of the shock absorber 19 so as to be rotatable about an axis perpendicular to the plane of the paper at a point P in the figure. Also, on the knuckle 15, a point P
A link 32 is integrally provided in the link 15.
The upper end of a is engaged with an actuator 28 fixed to the shock absorber 19.

Similarly, the rear wheels 12RR and +2RL have a brake drum 21 rotatably supported on a knuckle spindle 22, and a road wheel 12b supporting a tire 12a on the outer periphery.
It is fixed by Pols 1 to 14. The knuckle spindle building is rotatably attached to a bracket 19a fixed to the lower end of the shock absorber 19 at a point P in the figure, supported by the vehicle body via the shock absorber 19 and a spring 20, and is also provided integrally. A link 32 is engaged with an actuator 28 fixed to the shock absorber 19.

Referring again to FIG. 1, a pump 23 is engaged with the engine 11 via a belt 11a. This pump 23 is
It is connected to the reservoir tank 24 via a pipe P and also to a pressure regulating valve 25 via a pipe P2, so that the fluid in the reservoir tank 24 is pressurized and discharged. Pressure regulating valve 2
5 is connected to a front wheel servo valve 26F, a rear wheel servo valve 26R, and an accumulator 27 for storing pressurized fluid via a pipe P3, and is also connected to a reservoir tank 24 via a pipe P1. Pressure regulating valve 2
5, when the pressure of the fluid discharged by the pump 23 exceeds a predetermined value, the pressure of the fluid supplied to the servo valves 26F, 26R and the accumulator 27 is reduced by discharging the fluid to the reservoir tank 24 via the piping P%. Hold at a predetermined value. The front wheel servo valve 26F is connected to the right front wheel actuator 28FR and the left front wheel actuator 28FL via pipes P1, P,' and pipes Pg, P9', which are arranged in parallel. The ring servo valve 26R has pipes P7 and P7 arranged in parallel.
It is connected to the right rear wheel actuator 28RR and the left rear wheel actuator 28RL via ' and pipes P@, P, and '. These actuators 28 (hereinafter represented by numbers without subscripts as necessary) are the second actuators described above.
As shown in Fig. 3, the shock absorber 1
It is fixed at 9. These servos/<) reflex 26
F and 26R are energized by an amplifier to be described later, and the fluid whose pressure is regulated by the pressure regulating valve 25 is passed through the pipes P5, Po, and P5'.
, PQ', P7, PB, P7', P8' to each actuator 28 selectively.

As shown in FIG. 4, the actuator 28 has a piston 30 slidably fitted into a cylinder 29 to form two chambers 2.
9a and 29b and is fixed to a piston 30. A rod 31 is rotatably connected to a link 32 as shown in FIGS. 2 and 3.

The aforementioned chambers 29a and 29b each have a servo valve 26.
The piston 30 responds to the fluid pressure difference supplied from the servo valves 26F and 26R to the respective chambers 29a and 29b. In other words, the right front wheel actuator 2
8FL connects chamber 29a to piping P, and connects chamber 29b to piping P9.
The left front wheel actuator 28 FR is connected to chamber 2.
9a is the pipe P. Similarly, the right rear wheel actuator 28RR is connected to the chamber 29b.
The chamber 29b is connected to the pipe P8 by connecting the chamber 29a to the pipe P8, and the left rear wheel actuator 28RL connects the chamber 29a to the pipe P8.
Plumbing chamber 29b to 8' P? ' is connected to.

Each actuator 28 is provided with a stroke sensor 33 that detects the displacement of the piston 30. That is, as shown in FIG. 1, the right front wheel actuator 28
The right front wheel stroke sensor 33 FR is connected to the F R, the left front wheel stroke sensor 33FL is connected to the left front wheel actuator 28FL, the right rear wheel stroke sensor 33RR is connected to the right rear wheel actuator 28RR, and the left rear wheel actuator 28RL is connected to the right rear wheel stroke sensor 33 FR. A left rear wheel stroke sensor 33RL is provided, and these stroke sensors 33 are connected to a control unit 34, which will be described later.

The pump 23, the reservoir 24, the pressure regulating valve 25, the accumulator 27, the servo valves 26F and 26R, and the actuator 28 constitute a driving means 35.

36 is an acceleration sensor (acceleration detection means) that detects the acceleration of the vehicle in the vehicle width direction and outputs a signal corresponding to the cough acceleration; this acceleration sensor 36 is connected to the control unit 3;
I am doing tJ on 4th. The control unit 34 includes
The aforementioned stroke sensor 33 is connected, and two amplifiers 37F and 37R are also connected. This control unit 34 calculates the direction and magnitude of acceleration from the output signal of the acceleration sensor 36, and outputs a control signal to each amplifier 37F, 37R based on the calculation result. The amplifiers 37F and 37R are connected to the aforementioned servo valves 26F and 26R, respectively, and energize and drive the servo valve 26 based on input control signals. Note that the control unit 34 and amplifiers 37F and 37R are the control means 3.
8.

Next, the effect will be explained.

In this suspension system, the pump 23 is driven by the engine 11 to pressurize and discharge the working fluid in the reservoir 24, and the pressure of this working fluid is regulated by the pressure regulating valve 25 and supplied to the servo valves 26F and 26R. be done.

Here, when the vehicle is turning and zero acceleration occurs in the vehicle width direction, for example, as shown in FIG. 5, when vehicle width direction acceleration a toward the right in the figure is applied to the vehicle, This acceleration a is detected by the acceleration sensor 36, and a signal corresponding to the acceleration a is input to the control unit 34. The control unit 34 calculates the direction and magnitude Q of the acceleration a from the output signal of the acceleration sensor 36, and outputs a control signal corresponding to the direction and magnitude Q to each amplifier 37F, 37R.

Amplifiers 37F and 37R are connected to each servo valve 26F and 26
R is energized to supply working fluid to each actuator 2B, and the actuator 28 changes the camber of each wheel 12. That is, as shown by the arrow M in FIG. 5, the actuator 28 tilts both the left and right wheels 12 in the direction C toward the turning center to set the camber of the wheels 12 relative to the vehicle body to a value corresponding to the acceleration, and further tilts the left and right wheels 12 in the direction C toward the center of turning. Try to prevent the tire from deforming as shown in the diagram. Therefore, even if the vehicle body rolls, it is possible to maintain the ground camber of each wheel 12 at a constant value 1 regardless of acceleration, that is, centrifugal force. Canvas thrust, which acts in the opposite direction, is also reduced, improving the vehicle's turning performance.

Further, the camber of each wheel 12 is determined by a stroke sensor 33.
A signal corresponding to the camber of each wheel 12 is input to the control unit 34, and the control unit 34 performs feedback control. That is, the control unit 34 not only uses the output signal of the acceleration sensor 36 but also controls each wheel 1 output from each stroke sensor 33.
Since the control signal is output to the amplifiers 37F and 37R based on the signal indicating the camber of each wheel 12, the camber of each wheel 12 reliably has a value corresponding to the acceleration, and its reliability is high. Furthermore, in this example,
The control unit 34 controls the right front and rear wheels 12FR1 in accordance with the direction of the acceleration a detected by the acceleration sensor 36.
12RR stroke sensor 33FR133RR or left front and rear wheels 12F L, 12RL stroke sensor 33F L, 332 R1- output signal is used alternatively. It can be driven by servo valves 26F and 26R.

Note that the vehicle width direction acceleration can also be detected based on the vehicle speed and steering angle.

(Effects of the Invention) As explained above, the suspension system according to the present invention can cope with centrifugal force by tilting the wheels toward the turning center in response to the centrifugal force applied to the vehicle when the vehicle is turning. Because of the camber, it is possible to improve running stability by reducing canvas last, which acts to reduce cornering force, and it is also possible to reduce uneven tire wear.

[Brief explanation of drawings]

1 to 7 are diagrams showing a rack device on which an embodiment of the present invention is mounted, in which FIG. 1 is an overall configuration diagram, FIG. 2 is a sectional view showing the front wheel side in detail, Figure 4 is a cross-sectional view showing the rear wheel side in detail, Figure 4 is a cross-sectional view showing the actuator in detail, Figure 5 is a front view to explain the action, and Figure 6 is a cross-sectional view showing the deformation of the tire when turning. 7 are cross-sectional views showing the deformation of a tire during a conventional turn. 12---One wheel, 35---One drive means, 36---Acceleration sensor (acceleration detection means), 3B
-------One control means. Patent Applicant Nissan Motor Co., Ltd. Representative Patent Attorney Yugagun Part 4 Figure 3 28 Figure 5 C □ Figure 6 1-M Figure 7 76-

Claims (1)

[Claims] an acceleration detection means for detecting the acceleration of the vehicle in the width direction of the vehicle; a drive means capable of changing the camber of the wheels; and the drive means is controlled based on an output signal of the acceleration detection means, so that the camber of the wheels corresponds to the acceleration. and control means for changing the suspension.