JPH1058934A - Compliance controlling device for suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control compliance corresponding to a travelling state of a car, by supporting a connecting member to be linked with a wheel, by a shaft at a body side through a rubber bush, forming a fluid chamber on the rubber bush, and charging and discharging the fluid to the fluid chamber. SOLUTION: A rubber bush 2 supporting a tension rod or the like, comprises a pair of liquid chambers 6a, 6b, and these liquid chambers 6a, 6b are communicated through a passage 7. A switching valve 8 installed on the passage 7, is positioned on a switching position 8a in a normal condition, and is switched to a switching position 8b by the excitation to a solenoid 10, to cut off the passage 7. And the rigidity of the rubber bush 2 can be kept low, by switching the valve 8 to the switching position 8a, and communicating the passage 7, thereby the optimum compliance can be obtained in the normal travelling of the car. On the other hand, the rigidity of the rubber bush 2 is increased by switching the valve 8 to the switching position 8b, and cutting off the passage 7, thereby the tow variation of the tire can be inhibited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a suspension compliance control device capable of controlling suspension compliance in accordance with a running state of a vehicle.

[0002]

2. Description of the Related Art The term "compliance" is an expression that refers to the ease of bending in elastic deformation. Then, the compliance of the suspension is set by the mounting method of the linking member linked to the tire as the wheel. In the example shown in FIG. 12, the transverse link 1 linked to the tire t is supported at two points on the shaft 3 on the body side via the rubber bush 2. In the example shown in FIG. 13, the transverse link 4 linked to the tire t is supported by the shaft 3 on the body side via the rubber bush 2. Further, a tension rod 5 is connected to the transverse link 4 and the tension rod 5
Are also supported by a shaft 3 on the body side via a rubber bush 2. When a longitudinal force due to the cornering force of the tire t and a longitudinal force due to the driving force / braking force (for example, arrow L) are applied when the vehicle passes through the uneven road surface (for example, arrow L), 2 is displaced in the direction of the arrow to reduce the impact.

[0003]

It is assumed that, for example, stability control of a vehicle at the time of turning is being performed. In this stability control, the engine output and the braking force are controlled to reduce the tendency of the vehicle to oversteer or understeer. The yawing moment generated for relaxation is not stable, and the effect of the stability control is not sufficiently exhibited.

Alternatively, it is assumed that vehicle slip control is performed during braking and driving. In the slip control, the slip ratio of the tire t is detected, and the slip ratio is determined from the wheel speed. Therefore, if the tire t moves back and forth when detecting the slip ratio, the traveling speed between the axle and the vehicle body is shifted, and the detection accuracy is reduced. If an accurate slip ratio cannot be detected, the effect of the slip control will not be sufficiently exhibited. However, in order to sufficiently exhibit the effects of the stability control and the slip control, the tire t
If the compliance is set so as to suppress the displacement in the front-rear direction and the change in toe, that is, if the rubber bush 2 is made hard to bend, the shock is not absorbed and is transmitted to the steering wheel side, and the steering wheel operability during normal running is poor. turn into. An object of the present invention is to provide a suspension compliance control device capable of controlling compliance in accordance with a running state of a vehicle.

[0005]

According to a first aspect of the present invention, there is provided a compliance control device for a suspension, wherein a connecting member linked to a wheel is supported by a shaft on a body side via a rubber bush, and a fluid is attached to the rubber bush. It is characterized in that a chamber is formed and a fluid is taken in and out of the fluid chamber. According to a second aspect of the present invention, a connecting member linked to a wheel is supported by a shaft on a body side via a rubber bush, and a tip of a piston rod is linked to the shaft, and
It is characterized in that a cylinder in which the piston rod is slidably incorporated is connected to the connecting member, and a fluid is taken in and out of a fluid chamber of the cylinder.

According to a third aspect of the present invention, in the first or second aspect, a switching valve for communicating or shutting off the passage is provided in a passage process for taking fluid in and out of the fluid chamber, and this switching valve is controlled by a controller. The feature is that it is configured to switch. The fourth invention is characterized in that, in the third invention, a fixed throttle is provided in a passage process for taking a fluid in and out. According to a fifth aspect, in the first or second aspect,
A characteristic feature is that a variable throttle is provided in a passage process for taking fluid in and out of the fluid chamber, and the opening degree of the variable throttle is controlled by a controller.

[0007]

1 to 3 show a suspension compliance control apparatus according to a first embodiment of the present invention. FIG. 1 shows the above-mentioned transverse links 1, 4
Is a cross-sectional view of a rubber bush 2 supporting the or tension rod 5, an arrow k _1, k ₂ direction by the pair of liquid chambers 6a, 6
b is formed. Then, the pair of liquid chambers 6a,
6b is communicated via a passage 7, and a switching valve 8 is provided in the passage 7. In its normal state, the switching valve 8 is in the switching position 8a by the spring 9 and
However, when the solenoid 10 is excited, it is switched to the switching position 8b and the passage 7 is shut off.

If the switching valve 8 is at the switching position 8a,
Since passage 7 is communicated, for example, if the displacement the outer cylinder 31 in the arrow k ₁ in Fig. 1 in a state of fixing the shaft 3, the liquid chamber 6
The liquid a moves to the liquid chamber 6b via the passage 7. Similarly, if the displacement of the arrow k ₂ direction in FIG. 1, the liquid in the liquid chamber 6b is caused to move to the liquid chamber 6a through the passage 7. Therefore, at this time, the rigidity of the rubber bush 2 can be kept relatively low.
Then, an optimal compliance for maintaining the handle operability during normal running of the vehicle may be set based on the rigidity.

On the other hand, when the switching valve 8 is at the switching position 8b, the passage 7 is shut off, so that the liquid flows into the liquid chamber 6a,
6b. Then, for example, even if an attempt is displaced in the arrow k ₁ in Fig. 1, you can not move the liquid in the liquid chamber 6a, thereby suppressing a longitudinal displacement and toe change of the tire t. Similarly, even if an attempt is displaced in the arrow k ₂ direction in FIG. 1, you can not move the liquid in the liquid chamber 6b, will inhibit longitudinal displacement and toe change of the tire t. Therefore, at this time, the rigidity of the rubber bush 2 can be made relatively high. Then, compliance can be set by the rigidity so as to suppress the change in the toe of the tire t.

Here, stability control of the vehicle at the time of turning will be described. As shown in FIG. 2, the steering angle,
The vehicle speed, yaw rate, and lateral acceleration are detected by the sensors 11 to 14 and input to the stability control controller 15. Then, in the stability control controller 15, after the input signals are processed by the signal processing unit 16, the control unit 17 determines the running state of the vehicle. For example, when the slip angle of the vehicle body is large and the slip angular velocity is also large, it can be said that the vehicle has an oversteer tendency. On the other hand, if the actual yaw rate is smaller than the target yaw rate that should originally occur, it can be said that there is an understeer tendency.

When the control unit 17 determines that the vehicle has a tendency to oversteer or understeer,
The oversteer or understeer tendency is reduced as follows. When it is determined that there is a tendency to oversteer, a signal is output to the brake actuator 18 to apply a brake to the front wheel on the outside of the turn. Then, an outward yawing moment of the vehicle is generated to reduce the tendency to oversteer. On the other hand, when it is determined that the vehicle is understeering, a signal is output to the throttle actuator 19 to control the engine output, and a signal is output to the brake actuator 18 to apply a brake to the rear wheels. Then, the braking force of the rear wheels inside the turning is made larger than the braking force of the rear wheels outside the turning to generate an inward yawing moment of the vehicle, thereby alleviating the understeer tendency.

The stability control of the vehicle is performed as described above.
0 indicates that the solenoid 10 of the switching valve 8 is energized or not energized. That is, during normal running of the vehicle, the switching valve 8 is maintained at the switching position 8a without energizing the solenoid 10. Therefore, at this time, the rigidity of the rubber bush 2 can be kept relatively low, the optimum compliance for normal running can be set, and the steering wheel operability can be maintained.

On the other hand, when the control unit 17 determines that there is a tendency to oversteer or understeer,
At the same time, the controller 20 energizes the solenoid 10 and switches the switching valve 8 to the switching position 8b. Therefore, at this time, the rigidity of the rubber bush 2 can be made relatively high to make it difficult to bend, and the compliance can be set so as to suppress the displacement and the toe change of the tire t in the front-rear direction. If the displacement and the toe change of the tire t in the front-rear direction are suppressed, the yawing moment generated to reduce the tendency of oversteer or understeer can be stabilized.

According to the suspension compliance control apparatus of the first embodiment, the compliance can be controlled in accordance with the running state of the vehicle while the optimum compliance is set during normal running of the vehicle. And since the compliance control was coordinated with the stability control of the vehicle at the time of turning, the yawing moment generated to alleviate the tendency of oversteer or understeer can be stabilized, and the effect of the stability control can be sufficiently improved. Can be demonstrated.

The controller 20 includes a controller 1
Instead of transmitting the oversteer or understeer tendency determined in step 5, the signal processed by the signal processing unit 16 may be directly input as shown in FIG.
In this case, the calculation must be performed by the controller 20 as well.
If the tendency of oversteer or understeer is determined at an early stage, the compliance control of the suspension can be performed before the stability control. Further, the stability control controller 15 and the controller 20 need not be separately provided, and may be integrated.

In the second embodiment shown in FIG. 4, the liquid chambers 6a, 6a
By simply providing the fixed throttle 21 in the passage 7 communicating with b,
Other configurations are exactly the same as those of the first embodiment.
Therefore, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted. According to the suspension compliance control apparatus of the second embodiment, when the liquid moves between the liquid chambers 6a and 6b via the fixed throttle 21, excellent dynamic characteristics and a high damping effect can be provided. Generation of muffled sound can be suppressed.

In the third embodiment shown in FIG. 5, the liquid chambers 6a and 6
A variable throttle 22 is provided in the passage 7 communicating b instead of the switching valve 8 and the fixed throttle 21, and the opening thereof is controlled by the controller 20. Since the other configuration is exactly the same as that of the first embodiment, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted. According to the suspension compliance control device of the third embodiment, not only is the switching valve 8 unnecessary, but also the compliance can be set steplessly according to the opening of the variable throttle 22. Moreover, as in the second embodiment, when the liquid moves between the liquid chambers 6a and 6b via the variable throttle 22, excellent dynamic characteristics and a high damping effect can be provided, and the occurrence of shimmy and muffled sounds can be achieved. Can be suppressed.

The fourth embodiment shown in FIG. 6 is an example in which only one liquid chamber 6 is formed in the rubber bush 2. And
The liquid chamber 6 is connected to an accumulator 23 via a passage 7, and a switching valve 8 is provided in the passage.
Also in the fourth embodiment, when the switching valve 8 is at the switching position 8a, the passage 7 communicates, so that the liquid in the liquid chamber 6 moves to the accumulator 23 via the passage 7. Therefore, at this time, the rigidity of the rubber bush 2 can be kept relatively low. Then, it is sufficient to set an optimum compliance for maintaining the steering wheel operability during normal running of the vehicle, based on the rigidity. On the other hand, if the switching valve 8 is at the switching position 8b, the passage 7 is shut off, so that the liquid in the liquid chamber 6 cannot move.
Therefore, at this time, the rigidity of the rubber bush 2 can be made relatively high to make it difficult to bend, and the compliance can be set so as to suppress the displacement and the toe change of the tire t in the front-rear direction.

In the suspension compliance control device of the fourth embodiment, as in the first embodiment, the optimum compliance is set during normal running of the vehicle, but the compliance is controlled in accordance with the running state of the vehicle. can do. If the compliance control is coordinated with the stability control of the vehicle at the time of turning, the yawing moment generated to alleviate the tendency to oversteer or understeer can be stabilized, and the effect of the stability control can be sufficiently improved. Can be demonstrated. Of course, in the fourth embodiment as well, as in the second and third embodiments, the fixed throttle 2 is
1 may be provided, or a variable throttle 22 may be provided instead of the switching valve 8 and the fixed throttle 21.

In the fifth embodiment shown in FIGS. 7 to 10, the rubber bush 2 remains the same as the prior art, and
And the cylinder 25 control the compliance of the suspension. As shown in FIG. 7, the tip of the piston rod 24 is slidably connected to the shaft 3 via a ball joint, and is slidably connected to a cylinder 25 which is connected to the piston rod 24 and the traverse link 1 via a ball joint. It is slidably assembled. And, a pair of liquid chambers 25a partitioned in the cylinder 25,
25b through the passage 7 and the passage 7b.
Is provided with a switching valve 8. Also in the fifth embodiment, if the switching valve 8 is at the switching position 8a, the liquid is supplied to the liquid chambers 25a,
5b. Therefore, at this time, the compliance is determined by the rigidity of the rubber bush 2 itself. Then, it is sufficient to set an optimum compliance for maintaining the steering wheel operability during normal running of the vehicle, based on the rigidity.

On the other hand, if the switching valve 8 is at the switching position 8b, the liquid is sealed in the liquid chambers 25a and 25b, so that the liquid cannot move between the liquid chambers 25a and 25b. Therefore, at this time, the compliance is determined by the fluid pressure of the fluid chambers 25a and 25b in addition to the rigidity of the rubber bush 2 itself. Therefore, the rubber bush 2 is unlikely to bend, and the compliance can be set so as to suppress the displacement and the toe change of the tire t in the front-rear direction. In addition, as shown in FIGS. 8 to 10, the fluid may be taken in and out of the fluid chambers 25a and 25b.

For example, the one shown in FIG.
Is connected to the accumulator 23 via the switching valve 8. FIG. 9 shows two fluid chambers 25a and 25b.
Through a passage 7. And this passage 7
Is connected to the accumulator 23 via the switching valve 8. Furthermore, the one shown in FIG.
5b is communicated via a passage 7, and a switching valve 8 is provided in the passage 7. The passage 7 is connected to the accumulator 23. And these FIGS.
In the case of 0, since the accumulator 23 is provided,
The pressure in the passage 7 is set by the set pressure of the accumulator 23. Therefore, the compliance can be easily set again by changing the set pressure.

In the suspension compliance control apparatus according to the fifth embodiment, as in the first embodiment, while the optimum compliance is set during normal running of the vehicle, the compliance is controlled according to the running state of the vehicle. can do. If the compliance control is coordinated with the stability control of the vehicle at the time of turning, the yawing moment generated to alleviate the tendency to oversteer or understeer can be stabilized, and the effect of the stability control can be sufficiently improved. Can be demonstrated. In the fifth embodiment,
As in the second and third embodiments, the fixed throttle 21 is provided in the passage 7 or the variable throttle 2 is used instead of the switching valve 8 and the fixed throttle 21.
2 may be provided.

In the first to fifth embodiments, the compliance control is performed in coordination with the stability control at the time of turning. However, other control, for example, coordination with slip control may be performed. As shown in FIG.
When the vehicle is being braked or driven, the wheel speed is detected by a sensor 26 and input to a slip control controller 27. In the slip control controller 27, after the input signal is processed by the signal processing unit 28, the control unit 29
The slip ratio is determined from the detected value. When the slip ratio reaches the set slip ratio, the control unit 29 controls the brake 18 and the throttle actuator 1.
9 to prevent the vehicle from slipping.

When the control unit 29 calculates the slip ratio in this manner, the controller 30 simultaneously controls the switching valve 8
Is switched to the switching position 8b or the opening degree of the variable throttle 22 is reduced so that the rubber bush 2 is hardly bent and the tire t
In the front-rear direction and toe change. If the displacement and the toe change of the tire t in the front-rear direction are suppressed, the traveling speed between the axle and the vehicle body does not shift, and the wheel speed can be accurately detected. Therefore, the detection accuracy of the slip ratio can be maintained, and the effect of the slip control can be sufficiently exhibited. In these embodiments, a liquid is used as the fluid, but a gas may be used.

[0026]

According to the first and second aspects of the present invention, the compliance of the suspension can be controlled by taking the fluid in and out of the fluid chamber. Therefore, while the optimal compliance is set during normal running of the vehicle, the compliance can be controlled according to the running state of the vehicle. For example, if the compliance is set high in coordination with the stability control of the vehicle during turning, the yawing moment generated to reduce the tendency of oversteer or understeer can be stabilized, and the effect of the stability control can be sufficiently improved. Can be demonstrated. If the compliance is set high in coordination with the slip control of the vehicle at the time of braking or driving, the detection accuracy of the slip ratio can be maintained, and the effect of the slip control can be fully exerted.

According to the third aspect, in the first and second aspects, when the switching valve is switched, the compliance can be set in two stages. According to the fourth aspect, the third aspect
In the invention, excellent dynamic characteristics and high damping action can be provided, and the occurrence of shimmy and muffled sound can be suppressed. According to the fifth aspect, in the first and second aspects, not only the switching valve is not required, but also the compliance can be set steplessly according to the opening degree of the variable throttle. Moreover, similar to the fourth aspect, excellent dynamic characteristics and high damping action can be provided, and the occurrence of shimmy and muffled noise can be suppressed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a compliance control device for a suspension according to a first embodiment, and is a cross-sectional view of a rubber bush 2;

FIG. 2 is a circuit diagram of a suspension compliance control device coordinated with stability control.

FIG. 3 is a circuit diagram of a suspension compliance control device coordinated with stability control, showing another example.

FIG. 4 is a cross-sectional view of a rubber bush 2 illustrating a suspension compliance control device according to a second embodiment.

FIG. 5 is a diagram showing a suspension compliance control device according to a third embodiment, and is a cross-sectional view of a rubber bush 2;

FIG. 6 is a diagram showing a suspension compliance control device according to a fourth embodiment, and is a cross-sectional view of a rubber bush 2;

FIG. 7 is a diagram illustrating a suspension compliance control device according to a fifth embodiment.

FIG. 8 is a diagram showing another suspension compliance control device according to the fifth embodiment.

FIG. 9 is a view showing another suspension compliance control device according to the fifth embodiment.

FIG. 10 is a view showing another suspension compliance control device according to the fifth embodiment.

FIG. 11 is a circuit diagram of a suspension compliance control device coordinated with slip control.

FIG. 12 is a diagram showing a suspension of a vehicle.

FIG. 13 is a view showing another example of the suspension of the vehicle.

[Explanation of symbols]

 1, 4 traverse link 2 rubber bush 3 shaft 5 tension rod 6, 25 liquid chamber 7 passage 8 switching valve 15 controller for stability control 20, 30 controller 21 fixed restrictor 22 variable restrictor 24 piston rod 25 cylinder 27 controller for slip control

Claims (5)

[Claims] A connecting member linked to a wheel is supported by a shaft on a body side via a rubber bush, a fluid chamber is formed in the rubber bush, and fluid is taken in and out of the fluid chamber. Features a suspension compliance control device. 2. A connecting member linked to a wheel is supported by a shaft on a body side via a rubber bush, a tip of a piston rod is linked to the shaft, and the piston rod is slidably connected to the connecting member. A suspension compliance control device, wherein a built-in cylinder is linked, and fluid is taken in and out of a fluid chamber of the cylinder. 3. A switching valve for communicating or shutting off the passage in a passage process for taking fluid in and out of the fluid chamber, wherein the switching valve is switched by a controller. Or the suspension compliance control device according to 2. 4. The suspension compliance control device according to claim 3, wherein a fixed throttle is provided in a passage of the fluid. 5. A variable throttle is provided in a passage for taking fluid in and out of the fluid chamber, and the opening of the variable throttle is controlled by a controller.
Or the suspension compliance control device according to 2.