JP2538546B2 - Rear suspension of car - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rear suspension of an automobile.

(Prior Art) Conventionally, as a rear suspension of an automobile, for example, as disclosed in Japanese Utility Model Laid-Open No. Sho 58-18804, there are two lateral front and rear lateral wheels that extend in the vehicle width direction with respect to the vehicle body. It is known to be supported by a plurality of support points via suspension arms such as links.

In this type of rear suspension, in order to improve running stability, an elastic member is provided at at least one of the support points of the suspension arm, for example, a support point of the front lateral link, so that the lateral force is applied to the rear wheels. When an external force such as the above is applied, it is conceivable that both the rear wheels are directed inward of the vehicle body and a toe-in tendency is obtained due to the bending of the elastic member.

(Problems to be Solved by the Invention) However, in this case, even when the steering handle is largely turned to enter the garage, the elastic member, particularly the elastic member in the rear suspension opposite to the turning direction, acts on the rear wheel. By being similarly bent under the influence of cornering force as a lateral force, the rear wheels on the side opposite to the turning direction will face the inside of the vehicle, that is, the turning direction side, and as a result, turning response will be impaired. It will be.

An object of the present invention is to provide a toe-in tendency changing means such as changing the hardness of the elastic member as described above, and adjust and control the toe-in tendency of both rear wheels in accordance with the magnitude of the steering angle, so that when the vehicle goes straight. In addition, it is to achieve both the traveling stability at the time of gentle turning and the turning response at the time of sharp turning.

(Means for Solving the Problem) In order to achieve the above object, the solution means of the present invention is that the left and right rear wheels are supported by the vehicle body at a plurality of support points via respective arms, and an external force acts on the rear wheels. At this time, in a rear suspension of an automobile configured such that both rear wheels change in the toe-in direction, a toe-in tendency changing means provided in a portion where an external force received by the rear wheels acts between the vehicle body and each rear wheel. And steering angle detecting means for detecting the steering angle,
A second predetermined steering angle in which the steering steering angle is larger than the first predetermined steering angle as compared with the toe-in tendency of both rear wheels due to the external force acting on the rear wheels when the steering steering angle is the first predetermined steering angle. At this time, the control means controls the toe-in tendency changing means so as to weaken the toe-in tendency of both the rear wheels due to the external force acting on the rear wheels.

Here, the toe-in tendency changing means is, specifically,
For example, an elastic member having variable hardness is provided at at least one of the supporting points of the arm, and the toe-in tendency is changed by changing the hardness of the elastic member.

(Operation) With the above-mentioned configuration, the toe-in tendency changing means provided in the portion between the vehicle body and each rear wheel where the external force received by the rear wheel acts is controlled by the control means according to the magnitude of the steering angle. When the steering angle is small, the toe-in tendency of both rear wheels appears strongly. on the other hand,
When the steering angle of the steering wheel is large, such as when entering a garage, the toe-in tendency of both rear wheels is weakened.

(Effects of the Invention) Therefore, according to the present invention, the toe-in tendency changing means provided between the vehicle body and each of the rear wheels at the portion on which the external force received by the rear wheels acts, depending on the magnitude of the steering angle. Controlled,
When the steering angle is small, the toe-in tendency of both rear wheels is strong, and when the steering angle is increased to make a sharp turn, the toe-in tendency of both rear wheels hardly occurs. It is possible to effectively improve both the driving performance and the turning response at the time of a sharp turn, and it is possible to provide a rear suspension of an automobile which is excellent in practical use.

(Example) Hereinafter, the Example of this invention is described based on drawing.

In FIG. 1, reference numeral 1 denotes a steering device that steers left and right front wheels 2L and 2R. The steering device 1 includes a steering wheel 3 steered by a driver and a steering force of the steering wheel 3 in the vehicle width direction (left and right directions). Pinion that is converted to motion and transmitted
4a and rack 4b, left and right tie rods 5, 5 whose base ends are connected to each end of the rack 4b, one end connected to the tip of each tie rod 5, 5 and the other end connected to the left and right front wheels 2L, 2R, respectively. The knuckle arms 6 and 6 are provided, and the left and right front wheels 2L and 2R are steered left and right by moving the left and right tie rods 5 and 5 in the vehicle width direction according to the steering of the steering wheel 3. There is.

The steering device 1 also includes a power steering mechanism 7 for assisting the steering of the steering 3.
The power steering mechanism 7 has a hydraulic cylinder 8 having a rack 4b as an operating rod. Inside the hydraulic cylinder 8, a left turning hydraulic chamber 8a and a right turning hydraulic chamber 8b are integrally provided on the rack 4b. It is formed by being divided into left and right. The hydraulic chambers 8a, 8b communicate with the control valve 11 for controlling the oil supply direction to the hydraulic cylinder 8 and the hydraulic pressure via the hydraulic passages 10a, 10b, respectively. Hydraulic pump 13 is connected. The control valve 11 detects the rotation of the pinion 4a and connects the hydraulic pump 13 to the counterclockwise hydraulic chamber 8a of the hydraulic cylinder 8 when the front wheels 2L, 2R are steered to the left (steering clockwise in the figure). On the other hand, when the front wheels 2L, 2R are steered in the right direction (counterclockwise in the figure), the hydraulic pump 13 is communicated with the clockwise turning hydraulic chamber 8b of the hydraulic cylinder 8, and at the same time, the hydraulic pressure from the hydraulic pump 13 is transferred to the pinion 4a. The pressure is reduced to a pressure corresponding to the rotational force (that is, the steering force of the steering wheel 3). Therefore, when steering the steering wheel 3, the power steering mechanism 7 is configured to assist the steering of the steering wheel 3 by supplying pressure oil to the hydraulic cylinder 8 to move the tie rods 5, 5 in the vehicle width direction.

Reference numerals 14 and 14 denote rear suspensions for suspending the left and right rear wheels 15L and 15R on the vehicle body, respectively.
Is arranged in the vehicle width direction with a wheel support member 16 that rotatably supports the rear wheels 15L and 15R, and one end is rotatably connected to the wheel support member 16 and the other end to the vehicle body (subframe 17). Before and after the two lateral links 18,19
And the trailing rods 20 arranged in the front-rear direction of the vehicle body, the rear ends of which are connected to the wheel support member 16 and the front ends of which are rotatably connected to the vehicle body.
Is the lateral link above the suspension arm 18,19
Also, it is in a state of being supported by the vehicle body at three support points in a plane via the trailing rod 20.

Among the support points of the suspension arm of the rear suspension 14, the support point of the front lateral link 18 is, as shown in FIGS. 2 and 3, a support shaft 21 attached to the vehicle body and an outer periphery of the support shaft 21. An elastic member 22 made of rubber or the like is filled and fixed between the lateral link 18 and the cylindrical connecting portion 18a of the lateral link 18, and when an external force such as a lateral force acts on the rear wheels 15L and 15R, the elastic member The bending of 22 causes both rear wheels 15L and 15R to have a toe-in tendency toward the inside of the vehicle body. Further, between the elastic member 22 and the connecting portion 18a of the lateral link 18, a part of the elastic member 22 is wiped off at a vertical position sandwiching the support shaft 21 to remove the hydraulic chamber.
23, 23 are formed, and an oil introduction passage 25 branched from an oil return passage 24 in the hydraulic circuit system of the power steering mechanism 7 is provided in the hydraulic chambers 23, 23 on the support shaft 21. 26, the hardness of the elastic member 22 is changed by the level of the hydraulic pressure introduced into the hydraulic chambers 23, 23, and the elastic member 22 changes the toe-in tendency to change the toe-in tendency. Means are configured. In FIG. 2, 28 is a cap screwed to the end of the connecting portion 18a of the lateral link 18 so that the oil introduced into the hydraulic chamber 28 does not leak outside.

Further, 29 is a control valve provided at the downstream of the branch point of the oil return passage 24 with the oil introduction passage 25 (close to the oil tank 30), 31 is the steering angle of the steering wheel 3 (the steering angle of the front wheels 2L, 2R). It is a steering angle sensor 31 as a steering angle detecting means for detecting. The control valve 29 includes a valve body 29a that can adjust the passage area of the oil return passage 24 and a solenoid 29b that receives an output signal from the steering angle sensor 31 and operates the valve body 29a. Demonstrate the function as a control means to control the hardness of the elastic member 22 according to the size of the steering angle by expanding the passage area during small turns with small angles and narrowing the passage area during large turns with large steering angles. It is supposed to do.

Next, the rear suspension according to the present invention
The function and effect of 14 will be described.

When the steering angle of the front wheels 2L, 2R is small, the passage area of the oil return passage 24 in the hydraulic circuit system of the power steering mechanism 7 is not throttled by the control valve 29, and the oil return is smooth through the oil return passage 24. Therefore, the hydraulic pressure in the hydraulic chambers 23, 23 between the elastic member 22 communicating with the oil introducing passage 25 and the lateral link 18 connecting portion 18a in the oil introducing passage 25 becomes low, and this reduces the elasticity. The member 22 is easily deformed toward the hydraulic chambers 23, 23, and the hardness thereof is reduced. Therefore, when driving straight ahead or turning gently, when external force such as lateral force acts on the rear wheels 15L, 15R,
Since the elastic member 22 is easily bent and both rear wheels 15L and 15R have a large toe-in tendency, traveling stability can be improved.

On the other hand, when the steering angle of the front wheels 2L, 2R increases, the passage area of the oil return passage 24 is narrowed down by the control valve 29, and the hydraulic pressure in the hydraulic chambers 23, 23 increases accordingly, so that the elastic member The deformation of 22 toward the hydraulic chambers 23, 23 is restricted, and the hardness of the elastic member 22 increases. For this reason, even when cornering force acting as a lateral force acts on the rear wheels 15L, 15R on the side opposite to the turning direction when the vehicle steers sharply at a large steering angle for garage entry, etc., the rear wheels 15L, 15R
The R hardly bends toward the inside of the vehicle body, that is, in the turning direction due to the bending of the elastic member 22, and therefore the turning response can be improved.

The present invention is not limited to the above embodiment,
It also includes various other modifications. For example, in the above embodiment, the elastic member 22 having a variable hardness is provided at the supporting point of the front side lateral link 18 among the arm supporting points of the rear suspension 14, and the hardness of the elastic member 22 is controlled by the control means (control valve 29). The control is made to be small when the steering angle is small and to increase when the steering angle is large. However, in the present invention, an elastic member with variable hardness is provided at the support point of the rear lateral link 19, and the hardness of the elastic member is steered by the control means. The control may be performed such that the angle is large when the angle is small and the angle is large when the steering angle is large, or the both may be assembled. In short, when the steering angle is increased, the toe-in tendency of both rear wheels 15L and 15R may be weakened.

Further, the present invention is not limited to the rear suspension in which the rear wheels 15L and 15R are supported by the vehicle body at the three supporting points via the lateral links 18 and 19 and the trailing rod 20 as in the above-described embodiment, and Needless to say, the present invention can be similarly applied to various rear suspensions supported by the vehicle body at a plurality of supporting points via the arms.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a schematic view showing the overall configuration of a steering device and a rear suspension of an automobile, and FIG. 2 is a partially cutaway plan view showing a supporting point portion of a lateral link. 3 is a sectional view taken along line III-III in FIG. 3 …… Steering 14 …… Rear suspension 15L, 15R …… Rear wheel 18,19 …… Lateral link 20 …… Trailing rod 22 …… Elastic member (toe-in tendency changing means) 23 …… Hydraulic chamber 29 …… Control valve (Control means) 31 ... Rudder angle sensor (rudder angle detection means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Teruhiko Takatani No. 3 Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture Toyo Industry Co., Ltd. (72) Inventor Shigeki Furuya No. 3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Toyo Kogyo Incorporated (72) Inventor Yusuke Takema 8-5-2, Takahanadai, Maebashi-shi (72) Inventor Shima Gogo 17-1-1, 1-1 Otomachi, Maebashi-shi (72) Inventor Huita Asahigaoka-machi, Hiromaebashi-shi Address 7 (56) Reference JP-A-57-99470 (JP, A) JP-A-58-214470 (JP, A) JP-A-55-91458 (JP, A) JP-A-58-12811 (JP , A) Actual development Sho 57-60808 (JP, U)

Claims (2)

(57) [Claims] 1. An automobile having left and right rear wheels supported by a vehicle body at a plurality of supporting points via arms, and both rear wheels being changed in a toe-in direction when an external force acts on the rear wheels. In the rear suspension, the toe-in tendency changing means provided in a portion between the vehicle body and each rear wheel where the external force received by the rear wheels acts, the steering angle detecting means for detecting the steering angle, and the steering angle Compared to the toe-in tendency of both rear wheels due to the external force acting on the rear wheels at the first predetermined steering angle, when the steering steering angle is the second predetermined steering angle that is larger than the first predetermined steering angle, the rear wheels A rear suspension for an automobile, comprising: a control means for controlling the toe-in tendency changing means so as to weaken the toe-in tendency of both rear wheels due to an external force acting on the rear suspension. 2. The toe-in tendency changing means comprises an elastic member having variable hardness provided at at least one of the supporting points of the arm, and the toe-in tendency is changed by changing the hardness of the elastic member. The rear suspension of a vehicle according to claim 1, which is a vehicle.