JP2903758B2 - Vehicle suspension device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle suspension device, and more particularly to a vehicle suspension device capable of variably controlling a roll center height.

[0002]

2. Description of the Related Art As a conventional suspension apparatus for a vehicle, for example, a suspension apparatus described in Japanese Utility Model Laid-Open Publication No. 64-49404 is known and is shown in FIG. In FIG. 10, a suspension device 1 is a strut type device, and includes a strut 2, a lower link 3, a suspension member 4, a lower link bush 5, and the like. Assuming that the intersection (the instantaneous center of rotation of the wheel) between the line L ₁ passing through the strut upper mount 6 and perpendicular to the axis of the strut 2 and the extension L ₂ of the lower link 3 is O, the intersection O and the tire it is an intersection of the lines L ₃ and the center line L ₄ of the vehicle which connects the grounding point K.

[0003]

However, such a conventional vehicle suspension apparatus has a structure in which the height of the roll center is always substantially constant, so that it is affected by the vehicle weight condition, that is, the load capacity is reduced. Depending on the change in load, for example, Permissible Total Weight (hereinafter referred to as “P.
MW), it was difficult to maintain stability. SUMMARY OF THE INVENTION It is an object of the present invention to provide a vehicle suspension device capable of maintaining a constant drivability by moving a suspension member upward in response to an increase in a load.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a suspension member mounted to a vehicle body so as to be vertically movable, a link connecting a wheel and a suspension member, and a method of vertically moving the suspension member. An actuator to be driven, load detecting means for detecting a load on the vehicle, and driving of the actuator based on a detection result of the load detecting means such that the suspension member moves upward in response to the increase in the load. And control means.

[0005]

According to the present invention, the suspension member moves upward in response to the increase in the load, and the roll center height increases. Therefore, the stability is always kept constant without being affected by the load.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. 1 to 8 show a first embodiment of a vehicle suspension device according to the present invention, which is an example applied to a rear suspension. First, the configuration will be described.

In FIGS. 1 and 2, reference numeral 11 denotes a suspension member, and the suspension member 11 is connected to a vehicle body 13 via a member mount insulator 12.
The suspension member 11 is movable by the axial compliance of the member mount insulator 13. That is, the suspension member 11 is attached to the vehicle body 13 so as to be vertically movable. The suspension member 11 and the wheel 14 are connected by a lower link 15, and the end of the lower link 15 on the wheel side and the vehicle body 13 are struts.
They are linked by 16. A body of a hydraulic actuator 17 is fixed to the vehicle body 13, and a drive shaft of the hydraulic actuator 17 is fixed to the suspension member 11. Therefore, the hydraulic actuator 17 moves the suspension member 11 up and down. Roll center, the relative to the axis of the strut upper mount 18 through the struts 16 to the intersection point (instantaneous center of rotation of the wheel) of the extension line L ₂ of the line L ₁ and the lower link 15 at right angles with O, the intersection O and the tire it is an intersection of the lines L ₃ and the center line L ₄ of the vehicle which connects the grounding point K.

[0008] 19 is a rear wheel load sensor, 20 is a vehicle speed sensor, 21
Is a longitudinal acceleration sensor (hereinafter referred to as a longitudinal g sensor)
It is. The rear wheel load sensor 19 constitutes load detecting means for detecting the load of the vehicle. Each of the sensors 19, 20, and 21 is connected to a controller 22, and the controller 22 constitutes a control unit, and drives the hydraulic actuator 17 based on a detection signal from each of the sensors 19, 20, and 21 as described later. Control. That is, as shown in FIG.
By controlling the hydraulic control valve 23, the hydraulic pressure from the hydraulic source 24 is controlled and supplied to the hydraulic actuator 17. In addition, 25 is a drain.

Next, the operation will be described. Controller 22
The drive of the hydraulic actuator 17 is controlled based on the detection result of the rear wheel load sensor 19 so that the suspension member 11 moves upward in response to the increase in the loaded load. The relationship between the rear wheel load W detected by the rear wheel load sensor 19 and the hydraulic pressure P supplied to the hydraulic actuator 17 is shown in FIG.
Is shown as When the suspension member 11 moves upward, the pivot position of the lower link 15 on the suspension member side rises, and the roll center height increases. Therefore, the height of the roll center increases in response to the increase in the load. The relationship between the roll center height and the rear wheel load is shown, for example, in FIG. Although this embodiment is an example applied to a rear suspension, also when applied to a front suspension, the suspension member 11 is moved upward to increase the roll center height in response to an increase in the load, as described above. In the present embodiment, as described above, the roll center height is increased in response to the increase in the load, so that the roll moment can be reduced in response to the increase in the load, and the yaw damping can be improved. . Therefore, even when the load changes, the stability can always be kept constant.

The controller 22 controls the driving of the hydraulic actuator 17 based on the detection result of the vehicle speed sensor 20 so that the suspension member 11 moves downward in response to the increase of the vehicle speed. The relationship between the vehicle speed V detected by the vehicle speed sensor 20 and the hydraulic pressure P supplied to the hydraulic actuator 17 is shown, for example, in FIG. With this control, the roll center height decreases in response to the increase in vehicle speed. In this embodiment, since the roll center height is reduced in response to the increase in the vehicle speed, the load movement of the rear can be reduced at a high speed, and the total cornering force of the inner and outer wheels of the rear at the time of turning can be increased. Therefore, vehicle stability can be improved. On the other hand, when this embodiment is applied to the front suspension, the height of the roll center is increased in response to the increase in the vehicle speed, as a result,
Vehicle stability can be improved. The relationship between the vehicle speed and the roll center height when applied to the rear suspension and the front suspension is shown, for example, in FIG.

Further, the controller 22 responds to the increase in the absolute value of the longitudinal acceleration by
The drive of the hydraulic actuator 17 is controlled based on the detection result of the front-rear g sensor 21 so that moves downward. The relationship between the acceleration α detected by the longitudinal g sensor 21 and the hydraulic pressure P supplied to the hydraulic actuator 17 is shown, for example, in FIG. With this control, the roll center height is reduced in accordance with the increase in the absolute value of the longitudinal acceleration. In the present embodiment, the height of the roll center is reduced in accordance with the increase in the absolute value of the longitudinal acceleration, so that the vehicle stability can be improved. The operation of the hydraulic actuator 17 described above is based on the front engine / rear drive (hereinafter, FR)
This applies to vehicles. On the other hand, when this embodiment is applied to a front engine / front drive (hereinafter referred to as FF) vehicle, the roll center height is increased correspondingly to the absolute value of the longitudinal acceleration. As a result, front drift can be suppressed, and vehicle stability can be improved. On the other hand, this embodiment is applied to an FR car and an F car.
When applied to the front suspension of the F-car, the hydraulic actuator 17 is operated in the opposite direction to that applied to the rear suspension. As a result, vehicle stability can be improved. The relationship between the roll center height and the longitudinal acceleration when this embodiment is applied to an FR vehicle is shown, for example, in FIG.

FIG. 9 is a view showing a second embodiment of the vehicle suspension device according to the present invention. In FIG. 9, the same members as those of the first embodiment shown in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 9, reference numeral 31 denotes a connection shaft fixed to the vehicle body 13, and the suspension member 11 is connected to the connection shaft 31 via a member mount insulator 32. The member mount insulator 32 is of a sliding bush type, and the suspension member 11 is attached to the vehicle body 13 so as to be vertically movable. 33 is a dust cover.

In this embodiment, the same effects as those in the first embodiment can be obtained.

[0014]

According to the present invention, since the suspension member is moved upward in response to the increase in the load, the height of the roll center can be increased in response to the increase in the load. Security can always be kept constant.

[Brief description of the drawings]

FIG. 1 is a first view of a vehicle suspension device according to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS The schematic whole figure which shows an Example.

FIG. 2 is an explanatory diagram of a control method of a hydraulic pressure supplied to a hydraulic actuator in FIG.

FIG. 3 is a diagram showing a relationship between a hydraulic pressure supplied to a hydraulic actuator in FIG. 1 and a rear wheel load.

FIG. 4 is a diagram showing a relationship between a roll center height and a rear wheel load in FIG. 1;

FIG. 5 is a diagram showing a relationship between a hydraulic pressure supplied to a hydraulic actuator in FIG. 1 and a vehicle speed.

FIG. 6 is a diagram showing a relationship between a roll center height and a vehicle speed in FIG. 1;

FIG. 7 is a diagram showing a relationship between hydraulic pressure supplied to a hydraulic actuator in FIG. 1 and longitudinal acceleration.

FIG. 8 is a diagram showing the relationship between the roll center height and the longitudinal acceleration in FIG.

FIG. 9 shows a second embodiment of the vehicle suspension device according to the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS The schematic whole figure which shows an Example.

FIG. 10 is an overall schematic view of a conventional vehicle suspension device.

[Explanation of symbols]

 11 Suspension member 13 Body 14 Wheels 15 Lower link (link) 17 Hydraulic actuator (actuator) 19 Rear wheel load sensor (load detection means) 22 Controller (control means)

Claims (1)

(57) [Claims] 1. A suspension member movably mounted on a vehicle body, a link connecting the wheel and the suspension member, an actuator for moving the suspension member up and down, and load detecting means for detecting a load on the vehicle. Control means for controlling the driving of the actuator based on the detection result of the load detecting means so that the suspension member moves upward in response to the increase of the loaded load. apparatus.