JPH11245641A - Rolling control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent riding comfort at the time of high speed turning from being degraded by means of rolling control. SOLUTION: This device is provided with a traverse gravitational acceleration detecting means 1 detecting traverse gravitational acceleration to which a vehicle is subjected, and with a control means 5 which changes the damping force of a chock absorber to the direction suppressing the rolling of a vehicle so as to control the rolling of the vehicle, when traverse gravitational acceleration detected by the traverse gravitational acceleration detecting means 1 or its estimated value exceeds a shreshold set in advance. The threshold is varied in response to vehicle speed detected by a vehicle speed detecting means 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roll control device for a vehicle that appropriately controls a roll generated during traveling by adjusting a damping force of a shock absorber mounted on the vehicle.

[0002]

2. Description of the Related Art Generally, in a vehicle, the lower the unsprung weight and the heavier the sprung weight, the smaller the push-up from the road surface during running of the vehicle, and the better the riding comfort. In order to absorb the thrust, a spring SP having relatively high compliance as shown in FIG. 4 is interposed between the sprung weight W1 and the unsprung weight W2.

Further, in order to suppress the vibration of the spring SP at an appropriate speed to improve ride comfort and maneuverability, a shock absorber SA that absorbs the energy of the vibration includes a sprung weight W1 and an unsprung weight W2. Interposed in between.

Meanwhile, the vehicle vibrates during traveling under the influence of a road surface impact or steering, for example, around a center line (axis) in the traveling direction of the vehicle body, for example, in the direction of arrow H in FIG. Oscillating rolls (rolling) occur, which impairs the above-mentioned controllability of the vehicle.

On the other hand, there has been proposed a shock absorber in which the damping force of the shock absorber can be set in at least two stages in order to improve the operability by the roll. Normally, the ride comfort is emphasized, and the damping force is set softly. On the other hand, as shown in FIG. 5, when the lateral gravitational acceleration LG of the vehicle exceeds a predetermined threshold value εLG (step S1). ), The damping force of one of the left and right shock absorbers SA is hardly controlled and the other is softly controlled (step S2) to suppress the generated roll to an appropriate level.

[0006]

However, in such a conventional roll control method for a vehicle, the lateral gravitational acceleration LG of the vehicle is equal to the threshold εLG regardless of the traveling speed of the vehicle and the size of the turning radius. Is exceeded, the roll control is executed by immediately switching the damping force of the shock absorber SA. Therefore, even at a small steering angle, the roll control is executed at the time of high-speed turning of the vehicle, and as a result, the turning radius becomes large. Even in a traveling mode in which the lateral gravity acceleration hardly changes and does not affect the stability, as in the case of traveling at high speed on a highway, the roll control is performed and the riding comfort is deteriorated. There was a problem that.

SUMMARY OF THE INVENTION The present invention solves the above-described problems. When the vehicle travels at a high speed on a highway having a large turning radius, the vehicle does not immediately enter the roll control, thereby damping the shock absorber. It is an object of the present invention to provide a roll control device for a vehicle that can suppress frequent switching of forces and can surely prevent deterioration of the riding comfort of the vehicle during such high-speed turning.

[0008]

According to a first aspect of the present invention, there is provided a roll control apparatus for a vehicle, which is provided in a vehicle and detects a lateral gravitational acceleration received by the vehicle during traveling. Lateral gravitational acceleration detecting means, and a shock absorber for suppressing the roll of the vehicle when the lateral gravitational acceleration detected by the lateral gravitational acceleration detecting means or its estimated value exceeds a preset threshold value. Control means for switching control of the damping force, a vehicle speed detecting means for detecting the vehicle speed, and the threshold value being variable according to the vehicle speed.

According to a second aspect of the present invention, there is provided a roll control device for a vehicle in which a threshold value is not changed in a preset low speed range, but is gradually increased as the vehicle speed increases when the speed exceeds the predetermined speed range. It was done.

The roll control device for a vehicle according to the third aspect of the present invention is provided with a threshold value setting switch for setting the threshold value by manual operation.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block connection diagram showing a roll control device for a vehicle according to the present invention. The vehicle has a lateral gravitational acceleration detecting means 1 for detecting a lateral gravitational acceleration acting on a middle vehicle body and a vehicle speed detecting means 2 for detecting a vehicle speed.

The lateral gravitational acceleration detecting means 1 and the vehicle speed detecting means 2 respectively operate the actuators 4a, 4b, 4c, 4d for the shock absorbers 3a, 3b, 3c, 3d based on the detected outputs. Is connected to a control device 5 as a control means for controlling the operation of.
Here, each of the shock absorbers 3a, 3b, 3
c and 3d are provided between the vehicle body and each axle.

Further, the control device 5 is connected to a changeover switch 6 for switching between manual control and automatic control, and a threshold setting switch 7 for enabling a threshold value to be described later to be externally set by manual operation. . In addition, 8
Is a noise canceling capacitor connected to the threshold setting switch 7.

Further, the control device 5 previously stores in the memory the lateral gravitational acceleration data serving as a reference for suppressing the roll of the vehicle as a threshold value, and detects the lateral gravitational force detected during traveling. When the acceleration exceeds the threshold value, it functions to input a roll control output to each of the actuators 4a to 4d.

Further, the control device 5 sets the threshold value so as to change in accordance with the vehicle speed. That is, as shown in FIG. 2, the vehicle speed V is equal to the set vehicle speed (set value) V
In a low speed range until A, the threshold value εLG is a preset constant level, but in a speed range exceeding the set vehicle speed VA, the threshold value εLG is, for example, a characteristic that gradually increases in a proportional manner. (It may be an exponentially increasing characteristic).

Next, the operation will be described with reference to the flowchart of FIG. 3. First, the changeover switch 6 is opened to set the roll in the automatic control mode. As soon as the vehicle travels, a lateral gravitational acceleration signal is output from the lateral gravitational acceleration detecting means 1 and a vehicle speed signal is output from the vehicle speed detecting means 2 and input to the control device 5.

When the control device determines that the vehicle speed is equal to or lower than the set vehicle speed VA (step S11), the detected lateral gravitational acceleration LG is subsequently changed to the set constant value threshold value. It is determined whether or not εLG has been exceeded (step S12). If the threshold εLG has been exceeded, optimal roll suppression control according to the above characteristics is executed (step S13).

On the other hand, if the threshold value εLG is not exceeded, the roll suppression control is not executed. This makes it possible to maintain good riding comfort in the low-speed range.

On the other hand, when the vehicle travels at high speed while making a large turn on the highway, the lateral gravitational acceleration LG detected by the lateral gravitational acceleration detecting means 1 or the estimated value thereof is substantially constant and greatly changes. No negative impact on maneuverability.

In this case, under the condition that the current vehicle speed detected by the vehicle speed detecting means 2 exceeds the set vehicle speed VA (step S11), the control device 5 responds to the change in the vehicle speed as shown in FIG. As shown, the threshold value εLG is changed (step S14).

Therefore, when the lateral gravitational acceleration greatly changes beyond the threshold value, the damping force of each of the shock absorbers 3a, 3b, 3c, 3d is adjusted in the direction of suppressing the roll. (Step S13).

That is, according to the present invention, as the vehicle speed increases, the threshold value εLG is set higher accordingly, so that under a condition where the turning radius is large and the influence on the maneuverability is small, the lateral gravitational acceleration is obtained. The roll control is not performed immediately even if the value is large, so that the riding comfort does not deteriorate. Conversely, when a level of lateral gravitational acceleration that has a large effect on maneuverability occurs, the desired roll control is executed on condition that the threshold εLG is exceeded, and the vehicle is safely operated. Security and riding comfort can be ensured.

Further, according to such a method of setting the threshold value, frequent switching of the actuator by the roll control operation can be suppressed, and it is possible to prevent the ride comfort at the time of high-speed turning on the highway from being deteriorated.

In the above description, the case where the roll control is automatically switched in the roll automatic control mode using the threshold value stored in the memory in advance has been described. The control operation by the control device 5 is switched to the manual mode of the roll, and the threshold value setting switch 7 is manually operated to set the magnitude of the threshold value to an arbitrary level. Roll control according to the vehicle speed and the lateral gravitational acceleration can be realized depending on the vehicle and the type of the vehicle.

[0025]

As described above, according to the first aspect of the present invention, there is provided a lateral gravitational acceleration detecting means provided on a vehicle for detecting a lateral gravitational acceleration received while the vehicle is traveling.
When the lateral gravitational acceleration detected by the lateral gravitational acceleration detecting means or its estimated value exceeds a preset threshold value, control for switching the damping force of the shock absorber in a direction to suppress the roll of the vehicle. Means, the threshold value is made variable in accordance with the vehicle speed detected by the vehicle speed detection means. Even if the directional gravitational acceleration is large, it can be prevented from immediately entering the roll control, whereby the frequent switching of the shock absorber damping force can be suppressed, and the deterioration of the riding comfort during such high-speed turning can be reliably prevented. The effect is obtained.

According to the second aspect of the present invention, the threshold value is not changed in a preset low speed range, but is gradually increased as the vehicle speed increases when the speed exceeds the predetermined speed range. By adjusting the damping force of the shock absorber according to the magnitude of the lateral gravity acceleration below the set speed,
Ride comfort and maneuverability during low-speed running can be optimally maintained, while frequent switching of the shock absorber damping force during high-speed turning of the vehicle is reliably suppressed, and the ride comfort can be greatly improved. can get.

According to the third aspect of the present invention, since the threshold value setting switch for setting the threshold value by manual operation is provided, the vehicle body roll adapted to the driver's own driving feeling and the characteristics of the vehicle is provided. The effect that control can be performed arbitrarily is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a roll control device for a vehicle according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a threshold-vehicle speed characteristic of the control device in FIG. 1;

FIG. 3 is a flowchart showing a roll control procedure according to the present invention.

FIG. 4 is a conceptual diagram showing a general roll control mechanism of a vehicle.

FIG. 5 is a flowchart showing a conventional roll control procedure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lateral gravity acceleration detecting means 2 Vehicle speed detecting means 3a, 3b, 3c, 3d Shock absorber 5 Control device as control means 7 Threshold setting switch

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Noboru Yoshida, Inventor, 2-4-1 Hamamatsucho, Minato-ku, Tokyo World Trade Center Building Kayaba Industry Co., Ltd. (72) Takashi Kuniho 2, Hamamatsucho, Minato-ku, Tokyo 4-1 World Trade Center Building Kayaba Industry Co., Ltd.

Claims (3)

[Claims] 1. A lateral gravitational acceleration detecting means provided on a vehicle for detecting a lateral gravitational acceleration received while the vehicle is traveling, and a lateral gravitational acceleration detected by the lateral gravitational acceleration detecting means or an estimation thereof. A control means for switching the damping force of the shock absorber in a direction to suppress the roll of the vehicle when the value exceeds a preset threshold value. A roll control device for a vehicle, wherein the threshold value is variable according to the vehicle speed. 2. The vehicle according to claim 1, wherein the threshold value is not changed in a preset low speed range, but is gradually increased as the vehicle speed increases when the speed exceeds the predetermined speed range. Roll control device. 3. The roll control device for a vehicle according to claim 1, further comprising a threshold setting switch for setting a threshold by manual operation.