JPS60163714A - Automobile rear suspension - Google Patents

Abstract

PURPOSE:To control the transverse force toe-in tendency in the rear wheels for improving the running stability, by enabling the spring scharacteristics of elastic support means through which the support section of suspension arms is supported by an autobody to be controlled according to the speed of the automobile and the operation of a steering wheel. CONSTITUTION:A rear suspension has wheel supports 16a and 16b supported by a subframe 18 through front and rear suspension arms 13a, 13b and 14a, 14b, while the front suspension arms 13a and 13b are supported by the subframe through elastic support means 40 and 50. Pressure oil discharged by a pump 8 and controlled by a control valve 9 is introduced to these elastic support means 40 and 50 through a regulating means 20, whereby the spring characteristics of the elastic support means is enabled to be regulated. The regulating means 20 is controlled such that it increases the transverse force toe-in tendency according to increase in a speed signal from a speed sensor 31 and that it suppresses the transverse force toe-in tendency according to increase in a steering angle signal from a steering angle sensor 32.

Description

[Detailed Description of the Invention] <Industrial Application Fields> This book 5 relates to a rear suspension that rotatably supports the rear wheels of an automobile, and more specifically, to arbitrarily adjust the toe-in tendency of the rear wheels according to driving conditions. This is about the Liyanas Pension that has become possible.

(Prior Art) The rear wheels of automobiles are provided with a slight amount of toe-in from the viewpoint of running stability, and the magnitude of this toe-in m greatly affects the handling characteristics. In other words, the larger the amount of toe-in, the more stable the car becomes and the tendency to understeer becomes stronger, and the smaller the amount of toe-in, the more maneuverability (turning ability) increases and the tendency to understeer becomes weaker (the tendency to oversteer becomes stronger).
. Therefore, it is very important to appropriately set the +--in amount in order to obtain appropriate steering characteristics.In view of this, for example, the A rear suspension has been proposed in which the toe-in amount can be set to a desired value by providing two lower links and making it possible to adjust the connection position of each link with the vehicle body.

However, while it is desired that the vehicle has good stability when traveling straight, and good turning performance when turning,
As mentioned above, it is difficult to satisfy the conflicting characteristics of stability and turning performance by simply setting the amount of toe-in to a predetermined single shift, and usually a compromise between the two characteristics is achieved by setting the amount of toe-in to one shift.
I have no choice but to set it. In view of this, the above-mentioned links are connected through an elastic body, and when a lateral force acting on the wheel is received during turning, the elastic body is elastically deformed to reduce the amount of toe-in and improve turning performance. A so-called "humbrian steer" has been proposed, which aims to improve the straight-line stability and the ability to look back when turning.

On the other hand, requirements for stability and turning performance vary depending on the driving conditions of the vehicle. In other words, there is a demand to increase the lateral force-in tendency at high speeds to improve stability, and to reduce the lateral force 1-hein tendency at low speeds to improve turning performance.
When the steering angle is large, there is a demand to reduce the lateral force 1-1 inclination to improve retrospectivity, and when the steering angle is small, the lateral force 1-1 inclination is desired to be increased to improve stability.

(Object of the Invention) The present invention has been made in view of the above circumstances, and provides a rear suspension for an automobile that can control the tendency of the rear wheels to lateral close-in in accordance with the driving conditions determined by the vehicle speed, steering angle, etc. The purpose is to provide

(Structure of the Invention) The rear suspension of an automobile for use in motor vehicles is such that the support portion of the suspension arm is attached to the vehicle body via an elastic support means (
= J1), the spring characteristics of this elastic support means are adjusted by an adjustment means controlled by a control means that receives a vehicle speed signal and a steering wheel operation signal, so that as the vehicle speed increases, the lateral horn toe-in tendency increases, and the steering wheel operation increases. This feature is characterized in that the adjustment is made so as to suppress the horizontal quadrupling tendency. Note that the steering wheel operation signal refers to the steering angle of the steering wheel, the steering angle speed of the steering wheel, etc., and when the steering wheel operation increases, it means that these become larger.

The rear suspension of the present invention further comprises: an outer cylinder fixed to one of the elastic support means, the suspension arm, and the vehicle body; an inner cylinder fixed to the other; an elastic body disposed between these inner and outer cylinders; It is characterized in that it comprises a fluid chamber, and the fluid pressure in the fluid chamber is adjusted by an adjusting means to change the spring characteristics of the elastic support means.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing an example of an automobile having an A7 suspension according to the present invention, in which front wheels 1a and Ib are steered by a rack-binion type bower sparring mechanism. When the steering handle 2 is operated, its rotation is transmitted to the pinion 3 via the steering shaft 2a, and the rack 4 that meshes with the pinion 3 is moved in the width direction of the vehicle body. On the other hand, the piston fixed to the rack 4 is slidably inserted into the power cylinder tough,
The two cylinder chambers divided into two by the piston are connected to the control valve 9 via lines 9a and 9b, respectively. This control valve 9 selectively sends the pressure oil sent from the pump 8 via the line 8a to either of the two cylinder chambers via the line 9a or 911 according to the rotation of the steering shaft 2a. As a result, the piston receives the hydraulic pressure generated in the cylinder chamber, and the movement of the rack 4 in the vehicle width direction is power assisted. As described above, the operation of the steering wheel 2 allows the rack 4 to be moved in the width direction of the vehicle via the pinion 3, and the movement of the rack 4 is power assisted by sending pressure oil to the power cylinder 7 through the action of the control valve 9. It is. When the rack 4 is moved in the width direction of the vehicle body, the knuckles Ga and 6b are moved through tie rods 5a and 5b connected to both ends of the rack 4, respectively.
is rotated, and this knuckle 6a.

Front wheels 1a and 'lb rotatably supported by wheel 6b are steered.

In the front wheel power steering device configured as described above, the return line 10a of the control valve 9 branches into two parts midway, one being line 10CJ5 and line 1.
0d, 10e via elastic support means 40.5, which will be described later.
0, and the other one returns to the reservoir tank 19 from the line 10b via the adjustment means 20. The adjusting means 20 includes a housing 21 having a passage 24 connecting the line 10b and the server tank 19, a throttle piston 22 that is slidable within the housing 21 and changes the opening area of the passage 240 by this sliding, and the throttle piston 22. The operating signal to the solenoid 23 is sent from the control means 30 via a line 30a. Power is supplied to this control means 30 from a battery 33, and a vehicle speed signal from a vehicle speed sensor 31 and a signal corresponding to the steering angle of the steering wheel from a steering angle sensor 32 are inputted to the control means 30. hand,
Outputs an activation signal to the solenoid 23.

On the other hand, rear wheels 15a, 15b ha wheel support 1
6a.

161), and these wheel sabots 1-16a, 16b are rotatably supported by] Herre ring arm 17
a, 17b1 front suspension arm 13a,
13b and rear suspension arms 14a, 14
The front suspension arms 13a, 13b and rear suspension arms 14a, 14- are attached to the subframe 18, and the front suspension arms 13a, 13b are attached to the vehicle body by b.
The connecting portion with the subframe 18 is an elastic support means 40.5.
0 to the subframe 18. The toe-in m of the rear wheel is determined by these arms, especially the front and rear suspension arms 13a, 13b.
The influence of 114a and 141+ is large.

2 and 3 show a cross-section of the elastic support means 40, and the elastic support means 50 is also symmetrical in position with 40 ( ) and has the same structure. The outer cylinder 41 is the front suspension. The inner cylinder 42 is connected to the arm 13a, and is fixed to the subframe 18. Between the outer cylinder 241 and the cutter 12, it opens toward the front of the vehicle body (in the direction of the arrow F I'ont in FIG. 2) and opens in the vertical direction ( Fig. 3 Arrows Up and [)owr+ direction)
An elastic body 43 having two recesses 45b and 45c positioned at
b, is fluid-tightly attached to the outer cylinder 41 over the 450. Therefore, the outer cylinder 41, the lid 44 and the elastic body 4
3 and the recesses 45b and 45c form a fluid chamber 45. One end of a hole 42a penetrating the inner cylinder 42 back and forth opens into the fluid chamber 45, and the other end of the hole 42a is connected to the line 10d. Therefore, the fluid chamber 45 is filled with oil sent through the lines 10c and 10d, and the spring characteristics of the elastic support means 40 change under the influence of the oil pressure within the fluid chamber 45.

Specifically, when the oil pressure in the fluid chamber 45 is high, the spring constant becomes large, and the spring constant increases from the rear wheel 15a to the front suspension arm 13.
It is difficult to flex against the horizontal saw transmitted to a. On the other hand, if the oil pressure is low, the spring constant is small and it becomes easy to flex against the lateral force.

Normally, when a car turns, the outer wheels catch the side horns moving from the outside to the inside. For example, when the vehicle turns to the right in FIG. 1, the outer rear wheel 15a receives a lateral force from the outside to the inside as indicated by the arrow F. When receiving this lateral force, the elastic support means 40 deflects, and the toe-in of the rear wheel 15a does not increase. At this time, the smaller the spring constant of the elastic support means 40, the smaller the toe-in tendency, and the larger the spring constant, the smaller the toe-in tendency.
Although it is assumed that only the support part of the rear suspension arm 14a is elastically deformed, the shift is such that the support part of the rear suspension arm 14a is also elastically deformed so that the toe-in of the rear wheel 15a is not reduced when receiving a lateral force of 1. It is also possible. However, the elastic support means 40
The toe-in tendency that overlaps with the I imitation constant is exactly the same as above, and when the spring constant is small, the toe-in tendency increases,
The larger the spring constant, the smaller the toe-in tendency.

In the rear suspension of the present invention, the hydraulic pressure acting on the fluid chamber 45 of the elastic support means 40 is adjusted in accordance with the vehicle speed and the steering angle of the steering wheel to optimize the toe-in tendency.The operation thereof will be explained below.

The control means 30 receives signals from the vehicle speed sensor 31 and the steering wheel angle sensor 32, and controls the solenoid 23 through the line 30a so that the path 24 is changed to U as the medium speed increases.
Release F4 and send a signal to slide the throttle piston 22 so as to narrow the passage 24 as the steering angle increases. When the line j'1124 is narrowed down, the line 10ah+
+U10e oil pressure increases, so the elastic supporter (Q40
．． 50 fluid V 45 , airll in 55; i, f
The i3rd gear becomes lower as the vehicle speed becomes slower, and becomes higher as the wheel steering angle increases.For this reason, there is a tendency for lateral dot-in (the higher the vehicle speed, the lower the steering wheel angle becomes). The result will be as shown in Table 1.

Table 1? However, when the vehicle speed is high, the toe-in tendency is protected by stability, and at low speeds, the toe-in tendency is small and the turning performance is good, and at the same time, when the steering wheel steering angle is small and the vehicle is almost going straight, the steering wheel steering angle is large. The 1-1 inclination is increased to increase stability. This corresponds to the fact that stability is required at high speeds, and the requirement for turning performance becomes stronger as the speed increases. Take good care and turn”t
It satisfies the requirements for maneuverability during actual driving in an ideal manner.

FIG. 4 is a schematic diagram of an automobile having a different embodiment of the rear suspension of the present invention, and the same parts as in FIG. 1 are given the same numbers and their explanations will be omitted. In this embodiment, the control means 30 can receive signals from the steering angle speed sensor 34 in addition to signals from the vehicle speed sensor (1 and steering angle sensor 32'/). , based on these No. 1a, an activation signal is emitted to the solenoid 23 of the adjustment means 20. In this case, the toe-in tendency is controlled as shown in Table 1 with respect to vehicle speed and pan steering angle, and as the steering angle speed increases,
The one-in tendency is reduced to improve maneuverability on winding roads.

(Effect of Mikiaki) As explained above, according to Mikiaki, the toe-in tendency of the rear wheels can be controlled by the vehicle speed and steering angle, so it is possible to achieve appropriate steering stability for various driving modes. can. For example, at high speeds, the toe-in tendency is increased to ensure stability, at low and medium speeds, the toe-in tendency is reduced to maintain turning performance, and as the steering angle increases, the toe-in tendency is reduced to improve turning performance. By making it better, we can satisfy the need for retrospective performance in J5 at large steering angles, lll! Realizes imaginative handling characteristics.

In addition, in the present invention, it is possible to control the toe-in tendency not only by the vehicle speed and the steering wheel angle (but also by the steering wheel angular speed). For example, when driving on a winding road, turning performance is ensured according to the steering wheel angular speed. As a result, the maneuverability becomes poor.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the first embodiment of this Komei glue A7 suspension, Fig. 2 is an enlarged sectional view showing the elastic support means in Fig. 1, and Fig. 3 is an arrow shown in Fig. 2. FIG. 4, which is a sectional view taken along the line A-A, is a schematic view of a second embodiment of the rear suspension of the present invention. Ia, 1b...front wheel 3...binion 4...
Rack 7... Power cylinder 9... Control valve 20... Adjustment means 30... Control means 40
．． 50...Elastic support means 41...Outer cylinder 42...
・Inner cylinder 111 Fig. 5a Fig. 2 11iB Fig. s4 Fig. 5a

Claims (1)

[Scope of Claims] 1) A rear suspension in which a rear wheel is vertically movably supported by a suspension arm, wherein at least one of the vehicle body side support part and the wheel side support part of this → north suspension arm is supported. Elastic support means that is elastically attached to the vehicle body; adjustment means that adjusts toe changes due to side horns by changing the spring characteristics of the elastic support means in the vehicle width direction; and signals regarding vehicle speed and steering wheel operation. and control means for controlling the adjustment means in response to the increase in vehicle speed, and the control means increases the lateral corner-in tendency as the vehicle speed increases, and increases the lateral corner-in tendency as the steering wheel operation increases. A suspension for an automobile, characterized in that the adjustment means can be controlled so as to suppress a tendency toward intrusion. 2) The elastic support means includes a suspension arm fixed to either one of the vehicle body, an inner tube fixed to the other, an elastic body disposed between the outer tube and the inner tube, and the outer tube. a fluid chamber formed between the cylinder and the inner side, the adjustment means adapted to change the spring characteristics of the elastic support means by adjusting the pressure of the fluid leading to the fluid chamber. Characteristic claim 1
Rear suspension of the automobile described in section.