JPS6080915A - Rear suspension of car - Google Patents

Abstract

PURPOSE:To raise the steering performance and stability of a car, by forming rear wheels, as a change of toe occurs at rear wheels, when a lateral power is added to rear wheels while turing, and making right and left toe-changes different from each other. CONSTITUTION:A right rear wheel 3R is connected to the right end of a subframe 1 which is fixed to a car body, acting as a load on a spring, through the right swing-arm-type wheel supporting member 2R. This wheel supporting member 2R is formed of front and rear lateral links 4R, 5R, which extend nearly along the lateral direction of the car body, and a connecting link 6R, which extends along the longitudinal direction of the car body. Both ends of the links 4R, 5R are connected to supporting shafts 7R, 9R, which are projected from the sub frame 1, and to both ends of the connecting link 6R, through rubber bushes 8R, 10R-12R, respectively. Then, the said rubber bushes 8R, 10R-12R are selected as each of their hardness satisfies 8L<8R<10R=10L.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rear suspension for an automobile that cancels out the deflection characteristics when turning left and right so that the same steering characteristics can be obtained when turning left and right. .

(Prior Art) Some automobiles have different left and right steering characteristics due to their structure. In other words, for example, when turning to the left, the understeering tendency is stronger than when turning to the right. In FF cars (front-engine, front-drive cars), the load on the right front wheel is higher due to the arrangement of the engine, which is a heavy object. may be greater than the left front wheel load, or the left front wheel drive shaft may be shorter than the right front wheel drive shaft, and in FR vehicles (front engine front drive vehicles), the left rear wheel load may be greater than the right rear wheel load. In some cases, the right rear wheel drive shaft may be shorter than the left rear wheel drive shaft.

As shown in Japanese Utility Model Application Publication No. 56-141805, this difference in left and right steering characteristics can be corrected by changing the hardness of the rubber bushings on the left and right sides where the lower arm is attached to the vehicle body. There are some that cancel out the left and right steering characteristics caused by torque steer.

(Objective of the Invention) The present invention makes it possible to obtain similar left and right steering characteristics by fully addressing the differences in left and right steering characteristics caused by various causes and devising the rear suspension structure, particularly compliance. The purpose of the present invention is to provide a rear suspension for an automobile.

(Structure of the Invention) In order to achieve the above-mentioned object, in the present invention, the lateral force (cornering force) that acts on the rear wheels during turning is
In response to this, the rear wheels are configured to produce toe changes, and the toe changes on the left and right sides are different.

Specifically, the vehicle body and the arms are equipped with arms that are attached to the left and right sides of the rear of the vehicle so that they can swing vertically, and wheel supports that are connected to the arms and rotatably support the rear wheels. Two rubber bushings are disposed between the arm and the wheel support or at least one of the arm and the wheel support. The hardness of the rubber bushings is set within each pair so that the rear wheels are elastically deformed by the lateral force acting on the rear wheels when cornering, and the rear wheels change toe. so that the amount of toe change in the toe-in direction of the rear wheel on the side that becomes the outer wheel when turning is smaller than the amount of toe change in the toe-in direction of the rear wheel on the side that becomes the outer wheel when turning on the opposite side, Adjusted left and right.

(Example) First, in this example, it is assumed that the understeering tendency is stronger when turning left than when turning right.
The structure is designed to cancel out this difference in understeering tendency. Note that the suspensions for the left and right rear wheels basically have the same structure, so in the following explanation, the suspension for the right rear wheel will be explained. The suffix "L" will be used in place of the suffix "rRJ" and the redundant explanation will be omitted.

In FIGS. 1 and 2, l is a subframe fixed to the vehicle body as unsprung weight, and the subframe l includes:
A right rear wheel 3R is supported so as to be vertically movable via a swing arm type wheel support member 2R.

The wheel support member 2R has a front lateral link 4R and a rear lateral link 5R as arms extending substantially in the vehicle width direction, and a connecting link 6R as a wheel support extending in the longitudinal direction of the vehicle body. The inner end (inner end in the vehicle width direction) of the front lateral link 4R is connected to the rubber bush 8 with respect to the support shaft 7H protruding from the subframe l.
It is rotatably connected via R, and the rear lateral link 5R
The inner end (inner end in the vehicle width direction) is rotatably connected to a support shaft 9R protruding from the subframe 1 via a rubber bush 10R. In addition, the front lateral link 4R
The outer end of the rear lateral link 5R is rotatably connected to the front end of the connecting link 6R via a rubber bush 11R, and the outer end of the rear lateral link 5R is rotatably connected to the rear end of the connecting link 6R via a rubber bush 12R. Connected for free movement. A king pin 13R is protruded from the connecting link 6R, and the right rear wheel 3R is rotatably held around the king pin 3R.

The support shaft 7R19R and rubber bushes 8R, 10R, l
The axes of the lR112Rs extend in the longitudinal direction of the vehicle body, and therefore the right rear wheel 3R can swing vertically about the support shaft 7R18R. and,
The rear end of a tension rod 14R extending in the longitudinal direction of the vehicle body is rotatably connected to the connecting link 6R via a rubber bush 15R, and the front end of the tension rod 14H is provided to protrude from the vehicle body via a bush 16R. Plaquette)
It is rotatably connected to 17R. Of course 1. n (7
)1M bushes 15R and 16R extend in the vehicle width direction,
-F tension rod 14H ensures rigidity of the wheel support member 2H in the front-rear direction.

In FIG. 2, 18R is a hydraulic shock absorber installed between the connecting link 6R and the vehicle body, and 19R is a suspension spring that biases the hydraulic shock absorber 18R in the direction of extension.

It should be noted that each of the above-mentioned rubber bushes is generally constructed of an inner cylinder, an outer cylinder, and a rubber material filled between the two cylinders.

Both lateral links 4R and 5R of left and right support members 2R12L
The comrades 4L and 5L are non-parallel to each other, and the distance in the front-rear direction at each outer end is smaller than the distance in the front-rear direction at each inner end. Therefore, as is clear from FIG. 3, the center line extensions of the right front and rear lateral links 4R15R intersect on the outer side of the right rear wheel 3R, and the center line extensions of the left front and rear lateral links 4L and 5L intersect on the outer side of the right rear wheel 3R. The lines intersect on the outside of the left rear wheel 3L. Each of the above-mentioned intersection points is located on the wheel center which is on the same straight line as the king pin 13R113L.

Here, in this embodiment, the front and rear lateral links 4R14L
, 5R15L and the rubber bushes 8R18L and 10R11OL, which are the connecting parts to the subframe l, are adjusted in hardness to partially differ. That is, this hardness is the same as that of the rubber bushing 8 at the inner end of the left front lateral link 4L.
L is the smallest, followed by the rubber bush 8R at the inner end of the right front lateral link 4R, followed by the left and right rear lateral links 5.
The rubber bush l0R1IOL at each inner end of R15L is the largest (hardness is 8L<8R<1OR=10L
). In addition, the left and right lateral links 4R14L, 5R
Rubber bushings IIR, IIL, 12R at each outer end of 15L
The hardness of 112L is made equal to each other.

Next, the operation of the above configuration will be explained. Now, if the car turns to the left, a larger lateral force CFR (cornering force) will act on the outer right rear wheel 3R than on the inner left rear wheel 3L. At this time, the right wheel support member 2H receives a pressing force inward in the vehicle width direction, but the hardness of the rubber bush 8R of the connecting portion of the right front lateral link 4R to the subframe l is Since the hardness is smaller than that of the rubber bushing lOR of the connecting portion to the frame 1, the rubber bushing 8H is more elastically deformed than the IOR, and the right front lateral link 4R is displaced more inward to the vehicle body than the right rear lateral link 5R. As a result, the connecting link 6R rotates counterclockwise in FIG. 3, and the right rear wheel 3R tilts in the toe-in direction. Similarly, the left rear wheel 3L, which is the outer wheel that receives a large lateral force CFL when turning right, also leans in the toe-in direction because the hardness of the rubber bushing IOL is smaller than that of the left rear wheel 3L. As mentioned above, the hardness of the left rubber bushing 8L is smaller than the hardness of the right rubber bushing 8R, so the toe-in amount of the left rear wheel 3L, which becomes the outer wheel when turning right, is greater than that of the left rear wheel 3L, which becomes the outer wheel when turning left. The toe-in amount of the right rear wheel 3R is larger than that of the right rear wheel 3R. An increase in the amount of toe-in of the rear wheels means that the tendency for understeering becomes stronger.

Therefore, the left rear wheel 3L, which receives a large lateral force when turning to the right, undergoes a large toe-in change, so when turning to the right, the understeering tendency, which was originally weak, is corrected so that the understeering tendency is greatly emphasized, while when turning to the left, the understeering tendency is greatly emphasized. Since only a small toe-in change occurs in the right rear wheel 3R, which is the outer wheel that receives a large lateral force when turning, when turning to the left, where there is a strong tendency to understeering, the understeering tendency is only corrected to become slightly stronger, and as a whole, Similar steering characteristics can be obtained when turning left and right.

FIG. 4 shows another embodiment of the present invention, and the same components as those in the previous embodiment are given the same reference numerals and their explanations are omitted (this also applies to other embodiments below). ). In this embodiment, rubber bushings 8R18L of the connecting portions of the left and right front and rear lateral links 4R14L and 5R15L to the sub-arm 1,
Regarding the hardness of IOR and IOL, IOL is the largest, followed by IOR, and 8R and 8L are the smallest (
The hardness is 8R=8L<1OR<l0L). In this embodiment, the right rear wheel 3R, which receives a large lateral force when turning left,
When the connecting link 6R rotates counterclockwise in FIG. 4, it tilts in the toe-in direction. Similarly, the left rear wheel 3L, which receives a large lateral force when turning to the right, has its connecting link 6
When L rotates clockwise in FIG. 4, it tilts in the toe-in direction. And the rubber bush IOL is more IOL.
Since the hardness is greater than that of OR, the toe-in amount of the left rear wheel 3L is greater than the toe-in amount of the right rear wheel 3R. Therefore, in this case as well, as is clear from the description of the above-mentioned embodiments, similar steering characteristics can be obtained as a whole during left and right turns.

FIG. 5 shows still another embodiment of the present invention.

In this embodiment, the hardness of the rubber bushes 8R18L, IOR, and IOL at the connecting portions of the lateral links 4R51 4L and 5R15L to the subframe 1 is made equal, and the rubber bushes IIR, IIL, and 12 at their respective outer ends are made equal in hardness.
The hardness of R and 12L was adjusted. That is, rubber bushing 1. The hardness of R, IIL, 12R112L is the smallest for 11L, followed by llR, and the largest for 12R and 12L (hardness is IIL<IIR<12R).
=12L). In addition, rubber bushes 8R18L, 10R, I
The hardness of OL is made equal. In this example,
In the right rear wheel 3R, which becomes the outer wheel when turning left, the rubber bushing IIR at the front end of the connecting link 6R is replaced by the rubber bushing 12R at the rear end.
Since the hardness is smaller than that of the left rear wheel 3L, which causes the connecting link 6R to rotate counterclockwise in FIG. Tilt in the toe-in direction. And the rubber bushing I on the right
Since the hardness of the IR is greater than the hardness of the left rubber bush 11L, the toe-in amount of the right rear wheel 3R is greater than that of the left rear wheel 3L.
2, which is smaller than the toe-in amount. As a result, as in the case of the above-mentioned embodiment, the overall steering characteristic during left and right turns can be controlled.

In the case of an automobile in which the understeering tendency is stronger when turning to the right than when turning to the left, the relationship between the hardness of the rubber bushings in the above-described embodiments may be reversed from the above explanation. In addition, the hardness of the rubber bushing can be changed by changing the rubber material itself, or by making the inside of the rubber bushing hollow, or by forming a notch in a part of the rubber bushing. You can also do this.

(Effects of the Invention) As is clear from the above description, the present invention can cancel out the difference in steering characteristics between the left and right wheels caused by differences in the loads applied to the left and right wheels, and can obtain similar steering characteristics on the left and right wheels. , it is possible to improve the maneuverability and stability of automobiles. In addition, since it is only necessary to adjust the hardness of the rubber bushing, it can be easily applied to existing rear suspensions. In particular, in the present invention, since the rear suspension cancels out the above-mentioned left-right difference in steering characteristics, there are fewer restrictions than when dealing with the front wheels, which are the steered wheels, and there is a large degree of freedom in design. It is also advantageous from the perspective of reliability.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the present invention. Figure 2 is a rear elevational view of Figure 1. FIG. 3 is a simplified skeleton diagram of FIG. 1. FIGS. 4 and 5 are skeleton diagrams of parts corresponding to FIG. 1 showing other embodiments of the present invention. 3R13L; Rear wheel 4R14L; Front lateral link (arm) 5R15L;
Rear lateral link (arm) 6R56L; connection link (
Wheel support) 8R18L, l0R1IOL, ll
R111L, 12R112L; Rubber bushing 4 Fig. 2

Claims (1)

[Claims] (1) A rear suspension comprising arms attached to the left and right sides of the rear of the vehicle body so as to be swingable in the vertical direction, and wheel supports connected to the arms and rotatably supporting the rear wheels, Two rubber bushes are disposed between at least one of the vehicle body and the arm and between the arm and the wheel support, and the rubber bushes are each elastically deformed by a lateral force acting on the rear wheel when turning. The hardness of the rear wheels is set in each pair on the left and right so that the rear wheels change toe, and the rubber bushings in each pair are set so that the hardness of the rear wheels is set to change the toe of the rear wheels, which are the outer wheels when turning on the side with a strong understeer tendency among the left and right turns. The hardness is adjusted on the left and right sides so that the amount of toe change in the toe-in direction is smaller than the amount of toe change in the toe-in direction of the rear wheel on the side that becomes the outer wheel when turning on the opposite side. Rear suspension for automobiles.