JPS6033110A - Rear suspension for car - Google Patents

Abstract

PURPOSE:To improve the steering stability in turn by installing the second link between the top edge of the first link whose one edge is fixed onto a trailing arm and a subframe and forming a camber control mechanism, in a trailing-arm type rear suspension apparatus. CONSTITUTION:A camber control link mechanism 4 is constituted of the first control link 41 whose base part is fixed onto a semi-trailing arm 2, and the second control link 42 connected in turnable ways to the top edge of the first control link 41 and a subframe by means of ball joints 44 and 45. The ball joint 45 is eccentrically set by a set amount (e) with respect to the swing center axis line (l) of the trailing arm 2. Therefore, a difference is generated between the locus (q1) of turn of the connection point Q of the both links 41 and 42 and the locus (q2) of turn of the second control link 42, and the variation of the camber of a rear wheel is corrected in accordance with bump and rebound, and the steering stability in turn can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to rear suspensions for automobiles, and in particular, the present invention relates to rear suspensions for automobiles, and in particular, the present invention relates to a rear suspension of an automobile, and in particular, to a trailing arm type rear suspension such as a semi-trailing arm type or a full trailing arm type. Concerning control measures.

(Prior Art) Conventionally, as shown in Japanese Patent Laid-Open No. 58-12811, such a trailing arm type rear suspension supports a wheel rotatably and has elastic bushings at at least two locations at the base end. A semi-trailing arm is attached to the vehicle body via a semi-trailing arm that can swing vertically,
An assist link is provided, one end of which is connected to the rear of the wheel support part of the semi-trailing arm, and the other end of which is rotatably connected to the vehicle body, to change the toe-in of the wheel when a lateral force is applied to the wheel. It is known that the structure is as follows.

By the way, it is generally known that it is preferable to control the camber change of the wheel depending on the driving condition of the automobile. For example, it is preferable to set the wheels to negative camber when bumps occur due to cornering as this improves steering stability during cornering. Further, it is preferable to suppress the change in camber of the wheel to a small value when the vehicle bumps due to a rough road or rebounds when traveling straight, since this improves straight traveling performance.

However, with the conventional full trailing arm type rear suspension, the wheel and the rear suspension are
- There is no camber change in the wheel, and in the case of semi-trailing arm type wheels, the camber change of the wheel during bumps and rebounds is primarily determined by the inclination of the semi-trailing axis, and as mentioned above, Currently, it is not possible to control camber according to driving conditions.

(Objective of the Invention) The present invention applies engine braking to normally reduce deceleration during cornering, and when engine braking is applied, the differential gear case mounting subframe, which is elastically supported by the vehicle body near the rear suspension section, is affected by torque reaction force. Focusing on the rotational displacement of the vehicle body as it leans forward, based on this focus, in order to improve the steering stability of the above-mentioned trailing arm type rear suspension, especially during cornering, the rear wheel The purpose of this is to make it possible to change the camber to negative camber.

(Structure of the Invention) In order to achieve the above object, the structure of the present invention is such that the rear wheel is rotatably supported, and the base end is attached to a support member provided on the vehicle body through an elastic bushing so as to be swingable in the vertical direction. Take it”
In the rear suspension of an automobile having a bent trailing arm, a first control link whose base end is fixed to the first trailer arm, one end of which is fixed to the tip of the first control link, and the other end of which is elastically attached to the vehicle body. Second control links are rotatably connected to the supported subframe for attaching the differential gear case. As a result, when the engine brake is applied during cornering, the torque reaction force causes the subframe to rotate and displace to the front of the vehicle body. The camber is transmitted to the trailing arm via the camber, and the rear wheel is caused to change to negative camber under the elastic deformation of the elastic bushing that constitutes the pivot point of the trailing arm.

(Effects of the Invention) Therefore, according to the present invention, with a simple configuration of adding first and second control links to the existing trailing arm type rear suspension, the rear wheel can be controlled when the engine brake is activated during cornering. Since it can be changed to negative camber, it can greatly contribute to improving the steering stability during cornering and making it easier to implement.

(Example) Hereinafter, an example as a specific example of the technical means of the present invention will be described based on the drawings.

Figures 1 to 4 show semi-1-
A first embodiment in which the present invention is applied to a railing arm type rear suspension is shown.
The rear suspension structure is shown.

In FIGS. 1 to 3, reference numeral 1 denotes a subframe for attaching the differential gear case D to the vehicle body. It consists of two front frames 11 and 12, and a rear frame 13 extending in the vehicle width direction at a rear upper surface position of the differential differential gear case D (that is, a position above the front frames 11 and 12). Each of the above front frames 11
．． 12 are connected to the differential gear case D at their rear parts, and their front ends are rubber mounted to the vehicle body, while the rear frame 13 is connected to the differential gear case D at its center. Both left and right ends are rubber mounted to the vehicle body. Therefore, the subframe 1 is elastically supported at four points on the vehicle body in a forwardly inclined state integrally with the differential gear case D.

Further, 2 is a semi-trailing arm arranged approximately in the longitudinal direction of the vehicle body, and the remi-trailing arm 2 is
A bifurcated front member 21 and a substantially cylindrical rear member 22 are connected back and forth, and the cough rear member 22 includes a cylindrical rear wheel support portion 221 that rotatably supports the rear wheel W; A connecting portion 2 projects forward from the rear wheel support portion 221 and is connected to the forked base portion 211 of the front side member 21.
22, and a control link fixing portion 223 that protrudes inwardly and forwardly from the connecting portion 222 and to which a base end portion of a first control link 41, which will be described later, is fixed. On the other hand, as described above, the front member 21 is connected and fixed to the connecting portion 222 of the rear member 22 at the bifurcated base 211 by bolts 23, and the bifurcated branch portion 212 branches from the bifurcated base 211.
．． 212 each extend medially and anteriorly, and each bifurcation 2
The distal ends of the arms 12 and 212 (that is, the base ends of the semi-trailing arms 2) are each attached to a support member 3 provided on the vehicle body via elastic bushings 24 so as to be swingable in the vertical direction.

4 is a camber control link mechanism consisting of a first control link 41 and a second control link 42, and the base end of the first control link 41 is connected to the control link fixing part 222 of the semi-trailing arm 2. It is fixed to the rear wheel support portion 221 (that is, near the rear wheel support portion 221) with a bolt 43, and the tip portion extends inwardly and downwardly and forwardly. On the other hand, the second control link 42 is arranged in the vertical direction, and one end (lower end) thereof is rotatably connected to the distal end of the first control link 41 via a ball joint 44, and the other The end (upper end) is rotatably connected to the front frame 11.12 of the subframe 1 via a ball joint 45, and the length of the second control link 42 is the same as that of the first control link 41. It is set shorter than the length. Furthermore, the second control link 42 is connected to its subframe 1, as shown in FIG.
The side rotation center point P (ball joint 45) is installed with an offset of A set lie below with respect to the swing center axis 9 of the semi-trailing arm 2 (the line connecting both elastic bushes 24 and 24). There is.

In addition, 5 is a shock absorber arranged in the vertical direction,
The shock absorber 5 has its lower end at the rear end of the semi-trailing arm 2, that is, at the rear wheel support portion 221.
It is connected to a shock absorber mounting part 224 that protrudes rearward, and its upper end is connected to the vehicle body. Further, 6 is a coil spring arranged around the outer periphery of the shock absorber 5;
is a rear axle shaft that transmits driving force from the differential to the rear wheel W.

Next, the effects of the first embodiment will be explained with reference to FIGS. 1 and 5.

When a car turns while applying engine braking, a braking force toward the rear of the car body acts on the ground contact part of the rear wheel W, and this braking force is applied to the car body via the rear axle shaft 7 and the differential gear case D. By acting as a torque reaction force on the sub-frame 1 which is elastically supported by the sub-frame 1, the sub-frame 1 is rotationally displaced so as to be tilted more toward the front of the vehicle body than in the setting state.

At this time, the upper end is the front frame 11 of the subframe 1.
．． 12 and the first control link 41 whose base end is fixed to the semi-trailing arm 2 (ball joint 44)
As shown in FIG. 1, the rear wheel W is pushed downward with the rotational displacement of the subframe 1, so that the rear wheel W is connected to the vehicle body of the semi-trailing arm 2 via the first control link 41 and the semi-trailing arm 2. Under the elastic deformation of the side elastic attachment points (elastic bushings 24, 24), the vehicle changes to a negative camber so that it opens downward when viewed from the front and rear directions of the vehicle, resulting in improved steering stability when turning. can be done.

Further, when the rear wheel W bumps or rebounds, the rear wheel W swings vertically with respect to the vehicle body via the semi-trailing arm 2, and the first control link 41 and the second control link 4
It swings via a hinge control link mechanism 4 consisting of 2 and 4.

In this case, the rotation center point P (ball joint 45) on the vehicle body side of the camber control link mechanism 4 (second control link 42) is offset by a set amount e with respect to the swing center 1■ of the semi-trailing arm 2. As a result, as shown in FIG. A difference occurs between the rotation locus q1 of the rotation and the rotation locus q2 of the second control roll link 42 rotating about the vehicle body side rotation center point P. This trajectory difference becomes the camber control amount (correction amount) for the camber change of the rear wheel W due only to the swinging of the semi-trailing arm 2, and this camber control amount causes the rear wheel W to change due to the swinging of the semi-trailing arm 2. The camber change of W is corrected and controlled in response to bumps and rebound based on the elastic deformation of the elastic attachment point of the semi-trailing arm 2 on the vehicle body side.

This makes it possible to effectively make the rear wheel W into a negative camber when bumps occur due to cornering, in combination with the above-mentioned torque reaction force, thereby ensuring improved steering stability during cornering. be able to. Further, when the vehicle is traveling straight, the camber change of the rear wheel W can be suppressed to a small extent when bumps or rebounds occur due to rough roads, and the straight traveling performance can be improved. Furthermore, by taking advantage of the difference in order between the amount of bumps when cornering and the amount of bumps when driving on rough roads, you can set the rear wheel W to have a negative camber when driving when turning, and when driving straight on rough roads. It is possible to suppress the camber change to a small value, and the above-mentioned compatibility can be achieved.

Moreover, the base end of the first control link 41 in the camber control link mechanism 4 is fixed to the semi-trailing arm 2 near the V-wheel support part 221 (control link fixing part 223), so that the camber control link mechanism 4 By shortening the length over which the semi-trailing arm 2 is subjected to torsion, it is advantageous to improve torsional rigidity and reduce weight accordingly.

Further, the second control link 42 is arranged in the vertical direction and has a length equal to that of the first control link 42.
By setting it shorter than the length of the camber control link mechanism 4, the subframe side attachment point of the camber control link mechanism 4 can be raised, which is advantageous in terms of the layout of the A7 suspension, and also acts on the second control link 42. The load is in the tensile direction, which is advantageous in terms of strength.

In addition, since the camber change can be controlled in response to bumps and rebounds, the position of the semi-trailing arm 2 and the direction of the swing center axis 9 can be freely selected so as not to interfere with the vehicle body. The degree of freedom in designing the rear suspension can be increased.

6 to 8 show a second embodiment of the present invention applied to a semi-trailing arm type rear suspension having one attachment point on the vehicle body side. Note that the same members as in the first embodiment are the same. In this case, since the semi-trailing arm 2' has one attachment point on the vehicle body side, it is difficult to ensure lateral rigidity against lateral forces acting on the rear wheel W. This requires a lateral link 8.

That is, in this example, the semi-trailing arm 2
' consists of a front side member 21' and a rear side member 22', and the rear side member 22' has a rear wheel support part 221', a connecting part 222' and a control link fixing part 223', and the control link fixing part 223'. Part 223'
It has a lateral link attachment part 225' for attaching the lateral link 8 near thereto. On the other hand, the front member 21
' is connected and fixed at its rear end to a connecting part 222' of the rear side member 22', and its front end extends forward and connects to the vehicle body B.
It is attached via an elastic bushing 24' to a support member 3' provided in the support member 3' so as to be swingable in the vertical direction.

A lateral link 8 is disposed between the semi-trailing arm 2' and the vehicle body B, and one end of the lateral link 8 has an elastic force attached to the vehicle body side of the semi-trailing arm 2'. It is rotatably connected via a ball joint 81 to a mounting member 9 provided on the vehicle body at a position inward of the vehicle body from the bushing 24'), and the other end is a lateral link attachment portion of the semi-trailing arm 2'. 225' via a ball joint 82 to ensure lateral rigidity against lateral forces acting on the rear wheel W. Semi-trailing arm with points 2
' is configured to perform the same function as the semi-trailing arm 2 having two attachment points on the vehicle body side of the first embodiment.

Further, between the semi-trailing arm 2' and the lateral link 8, there is a link having the same structure as in the first embodiment, that is, the base end is fixed to the control link fixing part 223' of the semi-trailing arm 2'. The first control link 41 is connected to the front frame 11 of the differential gear case mounting subframe 1 whose lower end is elastically supported by the tip of the first control link 41 and whose upper end is elastically supported by the vehicle body B through ball joints 44 and 45, respectively. A camber control link mechanism 4 including a second control link 42 rotatably connected is installed. Note that the other configurations are the same as in the first embodiment.

Therefore, in the case of this example, the semi-trailing arm 2 having two attachment points on the vehicle body side in the first example is
Semi-trailing arm 2 with one attachment point on the body side
′ and the lateral link 8, the negative camber change of the rear wheel W is performed under the elastic deformation of one elastic bushing 24′ when the engine brake is applied during cornering, so that the negative camber change is facilitated. In addition to being advantageous in practice, the use of the lateral link 8 increases lateral rigidity and reduces weight.

It should be noted that the present invention is not limited to the first and second embodiments described above, but also includes various other modifications.

For example, in each of the above practical examples, we have described the case where it is applied to a semi-trailing arm type rear suspension.
Of course, the same can be applied to a full trailing arm type.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the invention, and FIGS.
Fig. 1 is a schematic explanatory diagram showing the rear suspension structure for the right rear wheel, Fig. 2 is a plan view of the same, Fig. 3 is a rear view of the vehicle seen from the rear of Fig. 2, and Fig. 4 is a schematic explanatory diagram showing the rear suspension structure for the right rear wheel. Fig. 2 is a partial side view when looking in the direction of arrow A in Fig. 5; For example, Figure 6 is a diagram equivalent to Figure 2, Figure 7 is a diagram equivalent to Figure 3,
FIG. 8 is a side view of the vehicle shown in FIG. 6 as seen from the inside. 1...Subframe, 2.2'...Semi-trailing arm, 221.221'...Rear wheel support part, 24.24'...Elastic bushing, 3.3'...
support member, 4. ... camber control link mechanism, 41 ... first control link, 42 ... second
Control link, W...Rear wheel, 9...
Semi-trailing arm swing center axis, P...2nd
Rotation center point on the subframe side of the control link, D.
...Differency V Luga case.

Claims (4)

[Claims] (1) A trailing arm that rotatably supports the rear wheel and whose base end is attached to a support member provided on the vehicle body so as to be able to swing vertically via an elastic bushing; a first control link fixed to the first control link, and a second control rotatably connected at one end to the tip of the first control link and at the other end to a differential gear 17 case mounting subframe elastically supported by the vehicle body. An automobile rear suspension characterized by comprising a link. (2) The second control link is installed such that its rotation center point on the sub frame side is offset by a set amount from the swing center axis of the trailing arm. rear suspension. (3) The rear suspension of the automobile according to claim (1) or (2), wherein the first control link has its base end fixed near the rear wheel support portion of the railing arm. . (4) The second control link is arranged in the vertical direction, and its length is set shorter than the length of the first control link.
) or (3).