JPS6060014A - Front suspension for automobile - Google Patents

Abstract

PURPOSE:To solve a problem of difference in symmetrical steering characteristics, by making a tilt in both suspension arms extending in a lateral direction of a car body, in case of a front suspension being different in steering characteristics at both sides in an engine horizontal type FF car or the like. CONSTITUTION:A front suspension is made up of attaching each of wheel support members 2a and 2b rotatably supporting symmetrical front wheels 1a and 1b to a car body 4 rockably in vertical directions by means of each of suspension arms 3a and 3b extending in the lateral direction of a car body. Likewise, each end part of knuckle arms 15a and 15b installed in each of these wheel support members 2a and 2b is coupled with a steering mechanism 6 via each of tie rods 7a and 7b. In this case, each tilt angle to a horizontal line in a support shaft La of these suspension arms 3a and 3b is set to being unequal at both sides, that is, making each tilt angle differ in a direction of eliminating a difference between both steering characteristics. With this constitution, difference in these symmetrical steering characteristics is eliminated.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a front suspension of an automobile.

In particular, the invention relates to a front suspension and steering system combination for a motor vehicle.

(Prior art) For example, in a front-engine, front-drive vehicle, if the engine is mounted horizontally, the center of gravity of the power unit, including the transmission mechanism, will be deviated laterally from the center line in the longitudinal direction of the vehicle, and the steering wheel The load on the left and right front wheels becomes different. 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 at the time of turning will be different when turning right and turning left, resulting in a difference in the left and right steering mechanisms. It makes a difference. In order to solve such problems,
- In No. 141805, front wheel suspension arm J
A structure has been proposed in which the elasticity of the comb bushings used to attach the steering wheel to the vehicle body is different between the left and right sides to offset the difference in steering characteristics between the left and right sides. 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 system for 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. The wheel support member rotatably supports the front wheels of the vehicle, and the tie rod connects the knuckle arm provided on the wheel support member to the steering mechanism of the vehicle.
This type has a difference in left and right steering characteristics, and the difference in left and right steering characteristics is canceled out by the inclination of the support shaft that extends in the front and back direction of the suspension arm with respect to the horizontal line. It is characterized by the fact that the left and right sides are different. To explain the principle of the present invention with reference to the drawings, in FIG.
, 2b rotatably supported. Wheel support member'l
a and 'lb are rotatably attached to the outer ends of suspension arms 3a and 3b extending in the lateral direction of the vehicle body, and inner ends of the suspension arms 3a and 3b are attached to the vehicle body 4 so as to be swingable in the vertical direction.

Knuckle arms 15a are attached to the wheel support parts IfA2a and 2b.
, 15b are provided, and these knuckle arms 15a, 15
The ends of b are each tyron doors a.

It is connected to the steering mechanism 6 via 7b.

With this type of suspension, steering interference occurs during bumps and rebounds. That is, referring to FIG. 2, when the right wheel 1a bumps, the suspension arm 2a is tilted with respect to the horizontal line, so the arm support shaft La extending in the longitudinal direction of the vehicle body causes the wheel 1a to move upward. It moves forward and backward at the same time. For example, when the suspension arm support axis La is tilted forward and downward, when the wheel 1a bumps, it is displaced forward from the solid line position in the figure to the position shown by the phase image line. Along with this, the connection point between the knuckle arm 15a and the tie rod 15a should move to the position shown by point A on the phase image line, but since the tie rod 7a cannot be expanded or contracted, it moves from the solid line position to the circular arc trajectory centered on the inner end. Displace along. Therefore, the outer end of the tie rod is actually displaced not to point A but to point B, which is inside of point A. Therefore, when the wheel 1a bumps, slight steering interference occurs in the toe-out direction. The magnitude of this displacement of the wheel in the toe-out direction depends on the magnitude of the inclination angle of the support shaft La of the suspension arm 2a with respect to the horizontal line.

(Effects of the present invention) In the present invention, the inclination angle of the suspension arm support shaft with respect to the horizontal line is not the same on the left and right sides, and the difference in the inclination angle is in a direction that cancels out the difference in left and right steering characteristics inherent in the automobile. Therefore, it is possible to comprehensively eliminate the difference in left and right steering characteristics. Furthermore, since there is no need to rely on the elastic modulus of the rubber cushion to cancel out the difference in left and right steering characteristics, a highly reliable mechanism can be obtained.

(Example) Referring to FIGS. 3 to 6, the right side wheel la is rotatably supported by a wheel support member 2a, and the left front axle is similarly rotatably supported by a wheel support member 2b. Supported. In the following, since the left and right structures are symmetrical, only the mechanism on the right side will be explained, and the corresponding parts of the mechanism on the left side will be shown with the same reference numerals as those on the right side, with the subscript ``s'' added instead of the suffix a on the right side. omitted.

An arm lla is formed on the wheel support portion +A2a, and the outer end of a suspension arm 3a is rotatably connected to the tip of this arm lla via a ball joint 12a. The suspension arm 3a is an A-shaped arm that extends in the lateral direction of the vehicle body, and its inner end is 2 arms spaced apart toward the rear of the vehicle body.
At this point, it is connected to the vehicle body 4 by rubber bushings 10a, lla.

Referring to FIG. 3, an arm 21a extending diagonally upward is formed on the vehicle body 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 the 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 a rank
It is of a binion type, and its steering shaft 20 is connected to a steering wheel (not shown) of an automobile.

Referring to FIG. 5, the support shaft La of the suspension engine arm 3a of the right front axle 1a is inclined forward and downward with respect to the horizontal line [■.With this structure, when turning left, the wheel 1a bumps and moves upward. When displaced, it moves slightly forward.

This forward movement -9 is regulated by the tie rod 7a, resulting in steering interference and the wheels 1a tending to understeer. On the other hand, the inclination of the left front axle 1b is smaller than that of the right side, and therefore, the steering interference tends to be weaker than in the left Jt rotation. Therefore, when turning to the right, the understeer I' is stronger than when turning to the left.
If this mechanism is adopted for a vehicle that shows a Jt direction or a vehicle that exhibits a stronger oversteer tendency when turning left than when turning right, it is possible to offset the difference in left and right steering characteristics. Furthermore, if the direction of inclination is reversed and the vehicle is tilted rearward and downward, steering interference appears as a tendency to oversteer on the hump side. Therefore, it is possible to cancel out the difference in steering characteristics of the left I4 for automobiles having steering characteristics opposite to those described above.

FIG. 6 shows an example in which the tyron doors a and 7b are located in front of the axles of the front wheels 1a and lb, unlike the previous example.

In this example, the steering interference tends to be opposite to the previous example. That is, when the suspension arm support axis La is tilted forward and downward, steering interference during bumping tends to result in oversteer. Its magnitude becomes stronger on the side with a larger inclination angle.

[Brief explanation of drawings]

FIG. 1 is a schematic plan 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. Figure 4 is its plan view, Figure 5 is
FIG. 6 is a side view of the right front suspension seen from the outside, and is a schematic plan view showing another embodiment. 1 a, 1 b ------- One front wheel. 2a, 2b------Wheel support member 3a, 3
b---------Suspension arm 5 a,
, 5 b---Suspension strut 6-
-----Steering mechanism

Claims (1)

[Claims] 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 able to swing vertically; and a wheel that is rotatably attached to the other end of the suspension arm and rotatably supports the front wheels of the automobile. a support member;
The suspension arm is composed of a tie rod that connects the knuckle arm provided on the wheel support part to the steering mechanism of the automobile, and in the front suspension of an automobile where there is a difference in steering characteristics between the left and right sides, the suspension arm cancels out the difference in steering characteristics between the left and right sides. An automobile suspension characterized in that the inclination of the support shaft extending in the front-rear direction with respect to the horizontal line is different on the left and right sides, as shown in FIG.