JPS6240203B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a front suspension of an automobile. In particular, the invention relates to a combination of front suspension and steering device of a motor vehicle.

(Prior art) For example, in a front-engine, front-drive vehicle, if the engine is installed horizontally, the center of gravity of the power unit, including the transmission mechanism, will be displaced laterally from the center line in the longitudinal direction of the vehicle. The load on a certain front wheel becomes different between the left and right wheels. Furthermore, in rear-drive automobiles that are often used by one person, the front wheel loads generally differ between the left and right wheels. If there is a difference in the left and right front wheel loads in this way, the sum of the cornering forces acting on the left and right wheels when turning will be different when turning to the right and when turning to the left, which will affect the left and right steering characteristics. It makes a difference. In order to solve this problem, in Utility Model Application No. 141805/1986, the elasticity of the rubber bushings used to attach the suspension arms of the front wheels to the vehicle body are made to differ between the left and right sides, thereby canceling out the difference in steering characteristics between the left and right sides. A new structure has been proposed. However, with this structure, when the elasticity of the rubber constituting the rubber bushing changes due to aging, etc., the desired effect cannot be achieved.

(Object of the Invention) In view of the above points, an object of the present invention is to provide a highly reliable mechanism that can cancel out the difference in left and right steering characteristics.

(Structure of the Invention) In order to achieve the above object, the present invention has the following structure. That is, the front suspension of an automobile according to the present invention includes a suspension arm on each side of the vehicle body that extends in the lateral direction of the vehicle body and has one end attached to the vehicle body so as to be swingable in the vertical direction, and a suspension arm that is rotatably attached to the other end of the suspension arm. A wheel support member that is attached to the wheel support member and rotatably supports the front wheels of the automobile, a suspension strut whose lower end is fixed to the wheel support member and whose upper end is rotatably attached to the vehicle body, and a knuckle arm provided on the wheel support member. It consists of a tie rod that connects the suspension arm to the steering mechanism of an automobile, and the left and right steering characteristics are different. It is characterized in that the distances are different between the left and right sides so as to cancel out the difference in steering characteristics between the left and right sides. To explain the principle of the present invention with reference to the drawings, in FIG.
b is rotatably supported. Wheel support member 2
a, 2b are rotatably attached to the outer ends of suspension arms 3a, 3b extending in the lateral direction of the vehicle body, and inner ends of the suspension arms 3a, 3b are attached to the vehicle body 4 so as to be swingable in the vertical direction. . Further, the lower ends of suspension struts 5a, 5b are fixed to the wheel support members 2a, 2b, and the upper ends of the suspension struts 5a, 5b are fixed to the vehicle body 4.
It is rotatably mounted on the Wheel support member 2
Although not shown in detail in FIG. 1, knuckle arms a and 2b are provided, and tie rods 7a and 7b connect the knuckle arms and the steering mechanism 6. This type of suspension is called a strut type, and steering interference occurs when the wheels bump or rebound. That is, referring to FIG. 2, when the wheel bumps and displaces upward from the position shown by the solid line, the suspension arm 3a swings upward around the attachment point to the vehicle body 4 to the position shown by the imaginary line. Accompanying this swinging, the suspension strut 5a also moves from the position shown by the solid line to the position shown by the imaginary line, and at the same time, the tie rod 7a also swings upward. At this time, if the steering angle of the wheel is maintained constant, the attachment point 8 of the tie rod 7a to the wheel support member will not move along the arc centered on the swing center 9, but will move to a point that deviates from the arc. It will reach 8A. However, since the tie rod 7a cannot be expanded or contracted, the above attachment point is actually the pivot center 9.
The wheel will move along an arc centered at and will reach point 8B, and the wheel will be rotated in the direction to increase or decrease the steering angle by an angle corresponding to the distance between points 8A and 8B. . That is, when a wheel bumps, the steering angle of the wheel is changed, which is what is called steering interference. This steering interference also occurs during rebound when the wheel is displaced downward, and the magnitude and direction of the steering interference is determined by the vertical distance between the attachment point of the tie rod to the knuckle arm and the attachment point of the suspension arm to the wheel support member. It depends on the distance ha in the direction. The present invention focuses on this point and makes the vertical distances ha and hb different between the left and right sides, thereby canceling out the difference in left and right steering characteristics inherent in automobiles. .

(Effects of the Invention) As described above, in the present invention, the vertical distance between the attachment point of the tie rod to the knuckle arm and the attachment point of the suspension arm to the wheel support member is not the same on the left and right sides. Since the difference in vertical distance is in the direction of canceling out the difference in left and right steering characteristics inherent in the automobile, it is possible to eliminate the difference in left and right steering characteristics in a comprehensive manner. Furthermore, since there is no need to rely on the elastic modulus of the rubber bushing to cancel out the difference in left and right steering characteristics, a highly reliable mechanism can be obtained.

(Example) Referring to FIGS. 3 and 4, the right front wheel 1a is rotatably supported by a wheel support member 2a, and the left front wheel 1b is similarly supported by a wheel support member 2a.
b is rotatably supported. In the following, since the structures on the left and right sides are almost symmetrical, only the mechanism on the right side will be explained, and corresponding parts of the mechanism on the left side will be indicated by the same reference numerals as those on the right side, with a subscript b added instead of the subscript a on the right side. The explanation will be omitted.

An arm 11a is formed on the wheel support member 2a, and the outer end of a suspension arm 3a is rotatably connected to the tip of the arm 11a via a ball joint 12a. The suspension arm 3a is an A-type arm that extends in the lateral direction of the vehicle body.
The inner end is connected to the vehicle body 4 at two points separated in the longitudinal direction of the vehicle body by rubber bushes 10a and 11a.

Referring to FIG. 3, an arm 21a extending obliquely upward is formed on the wheel support member 2a, and the lower end of a suspension strut 5a is fixed to the tip of this arm 21a. The upper end of the suspension strut 5a is rotatably attached to the vehicle body 4.

A knuckle arm 15a is provided on the wheel support member 2a so as to extend diagonally rearward, and the tip of this knuckle arm 15a is connected to the outer end of the tie rod 7a. The inner end of the tie rod 7a is connected to one end of the steering mechanism 6. In this example,
The steering mechanism 6 is of the rack and pinion type, and its steering shaft 20 is connected to a steering wheel (not shown) of the automobile.
In FIG. 3, the center C ₁ of the joint connecting the right tie rod 7a to the knuckle arm 15a
and the suspension arm 3a to the wheel support member 2.
Ball joint 1 connected to arm 11a of a
The vertical distance between center C ₂ of 2a is smaller than the corresponding distance in the left suspension. As shown in the illustrated example, when the tie rod is located behind the wheel center and the suspension arms 3a, 3b and tie rods 7a, 7b are both approximately horizontal, steering interference will tend to understeer in both bumps and rebounds. Under the above-mentioned vertical distance relationship, the magnitude of steering interference is stronger when turning to the right than when turning to the left. In other words, the understeer tendency is stronger when turning to the right. Therefore, if this mechanism is adopted for a vehicle that exhibits a stronger understeer tendency when turning left than when turning right, or a vehicle that exhibits a stronger oversteer tendency when turning right than turning left, the left and right steering characteristics will change. can cancel out the difference.

FIG. 5 shows another embodiment of the present invention,
In this example, the knuckle arms 15a, 15b protrude forward from the wheel support members 2a, 2b, and the tie rods 7a, 7b are arranged forward from the centers of the front wheels 1a, 1b. With this arrangement, steering interference creates a tendency for oversteer. As in the previous example, the difference in steering characteristics can be canceled out.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view of a front suspension illustrating the principle of the present invention, FIG. 2 is a schematic diagram illustrating the principle of steering interference, and FIG. 3 is a rear view of the front suspension illustrating an embodiment of the present invention. FIG. 4 is a plan view thereof, and FIG. 5 is another embodiment of the present invention. 1a, 1b...Front wheel, 2a, 2b...Wheel support member, 3a, 3b...Suspension arm, 5a,
5b...Suspension strut, 6...Steering mechanism, 7a, 7b...Tie rod.

Claims (1)

[Claims] 1 Suspension arms on each side of the vehicle body that extend in the lateral direction of the vehicle body and have one end attached to the vehicle body so as to be swingable in the vertical direction, and a suspension arm that is rotatably attached to the other end of the suspension arm and allows the front wheels of the automobile to rotate freely. a suspension strut whose lower end is fixed to the wheel support member and whose upper end is rotatably attached to the vehicle body; and a tie rod that connects the knuckle arm provided on the wheel support member to the steering mechanism of the vehicle. In a front suspension of an automobile that has different left and right steering characteristics, the vertical distance between the attachment point of the tie rod to the knuckle arm and the attachment point of the suspension arm to the wheel support member is The front suspension of an automobile is characterized by being different on the left and right sides to cancel out the difference in steering characteristics.