JPS6251163B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to rear suspensions for automobiles, and particularly to rear suspensions of a trailing arm type such as a semi-trailing arm type or a full trailing arm type. Concerning countermeasures for camber control during rebound.

(Prior Art) Conventionally, as such a trailing arm type rear suspension, as shown in Japanese Patent Application Laid-open No. 58-12811, a wheel is rotatably supported,
a semi-trailing arm whose base end is vertically swingably attached to the vehicle body via elastic bushings at at least two locations;
It is known that the wheels are provided with assist links whose other ends are rotatably connected to the vehicle body, and are configured to change the toe-in of the wheels when a lateral force is applied to the wheels.

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

However, with conventional full trailing arm type rear suspensions, there is no camber change in the wheel during bumps or rebound, and with semi-trailing arm type rear suspensions, the wheel camber does not change during bumps or rebound. At present, the camber change is uniquely determined by the inclination of the semi-trailing axis, and it is not possible to control the camber according to the driving conditions as described above.

(Object of the Invention) In view of the above, an object of the present invention is to provide a trailing arm type rear suspension as described above with a simple configuration in which a camber control mechanism consisting of a link mechanism is installed at an appropriate position. The object is to be able to effectively control camber changes according to rebound, and to enable camber control adapted to driving conditions.

(Structure of the Invention) In order to achieve the above object, the technical solution of the present invention is such that the rear wheel is rotatably supported, and the base end is attached to the vehicle body via an elastic bushing so as to be swingable in the vertical direction. In a trailing arm type rear suspension equipped with a trailing arm,
A lateral link has one end rotatably connected to the vehicle body at a position inside the vehicle body from the attachment point of the trailing arm on the vehicle body side, and the other end is rotatably connected to the vehicle body via a ball joint near the rear wheel support portion of the trailing arm. a first control link having a base end fixed to the trailing arm; and a second control link having one end rotatably connected to the tip of the first control link and the other end rotatably connected to the vehicle body. The second control link is arranged vertically in front of the vehicle body relative to a vertical plane that includes the pivot axis of the trailing arm, and the pivot point on the vehicle body side is aligned with the trailing arm's pivot axis. It is installed with a set amount of offset below the vehicle body with respect to the center axis of the swing.

As a result, during a bump or rebound, the first control link and the second control link are offset by the offset of the pivot point on the vehicle body side of the second control link located in front of the pivot axis of the trailing arm. There is a difference between the rotation locus of the connection point with the link about the pivot axis of the trailing arm and the rotation trajectory about the vehicle body side rotation center of the second control link. During a bump where the point is displaced to the rear of the vehicle, the difference is small when the bump amount is small, and a large difference occurs when the bump amount is large, and this trajectory difference is the amount of rear wheel camber control during bumps and rebounds. (correction amount), the camber change of the rear wheel is controlled in response to bumps and rebound under the elastic deformation of the elastic bush that constitutes the pivot point of the trailing arm.

(Effects of the Invention) Therefore, according to the present invention, by adding a camber control link mechanism consisting of first and second control links to an existing trailing arm type rear suspension, the following can be achieved. Since the change in camber of the wheel can be controlled in accordance with bumps and rebounds, negative camber can be achieved when turning with a relatively small amount of bumps, and the steering stability can be improved. On the other hand, when the amount of bumps is large, the amount of camber control increases, so that changes in camber during straight-ahead travel can be effectively suppressed, and straight-ahead stability can be reliably improved.

Furthermore, in the case of the semi-trailing arm type, where the camber change is determined uniquely, the camber change can be controlled, which reduces restrictions on the placement of the semi-trailing arm and increases the degree of freedom in designing the rear suspension. It also has the advantage that it can be increased.

Furthermore, the lateral link that regulates the lateral displacement of the wheel is separate from the drive shaft that drives the wheel, so the swing axis of the trailing arm can be freely adjusted as appropriate regardless of the arrangement of the dry shaft. Can be set.

In addition, since both ends of the lateral link are connected by a ball joint, the displacement of the arm in the camber direction due to the vertical movement of the wheel is
Lateral links do not have any binding force; first,
The function of the second control link mechanism can be maximized.

Furthermore, since the center of rotation of the second control link on the vehicle body side is offset to the lower part of the vehicle body, the rear seat hit point can be placed as low as possible, helping to secure interior space. It is always advantageous.

(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 an embodiment in which the present invention is applied to a semi-trailing arm type rear suspension having one attachment point on the vehicle body side. It shows.

1 to 4, reference numeral 1 denotes a semi-trailing arm disposed approximately in the longitudinal direction of the vehicle body, and the semi-trailing arm 1 includes a channel-shaped front member 11 and a substantially cylindrical rear member 12.
The rear member 12 includes a cylindrical rear wheel support part 121 that rotatably supports the rear wheel W, and a rear part of the front member 11 that protrudes forward from the rear wheel support part 121. A connecting part 122 connected to the end, and a first control link 3 which projects inwardly and forwardly from the connecting part 122 and which will be described later.
a control link fixing part 123 to which the base end of the control link fixing part 123 is fixed;
It has a lateral link attachment part 124 protruding inwardly from the rear wheel support part 121 near the rear wheel support part 121 to which a lateral link 2, which will be described later, is attached.
On the other hand, the front member 11 is connected and fixed at its rear end to a connecting portion 122 of the rear member 12 with bolts 13, and its front end (that is, the base end of the semi-trailing arm 1) extends forward. It is attached to the vehicle body at one point via an elastic bushing 14 so as to be swingable in the vertical direction.

Further, 2 is a lateral link arranged between the semi-trailing arm 1 and the vehicle body,
The lateral link 2 has one end connected to the vehicle body side attachment point of the semi-trailing arm 1 (elastic bushing 1).
4) is rotatably connected to the vehicle body via a ball joint 21 at a position inward of the vehicle body, and the other end is connected to the ball joint 22 at the lateral link attachment portion 124 (near the tip portion) of the semi-trailing arm 1.
The rear wheel W is rotatably connected to the rear wheel W to ensure lateral rigidity against lateral forces acting on the rear wheel W. In addition, this lateral link 2 and the above semi-trailing arm 1 are connected to the rear wheel W.
is configured to be supported so as to be able to swing vertically relative to the vehicle body, and there is a straight line connecting the attachment points (elastic bushing 14 and ball joint 21) of the semi-trailing arm 1 and the lateral link 2 on the vehicle body side, that is, the semi-trailing arm 1 and the lateral link 2. The swing center axis l of the ring arm 1 is inclined at a predetermined angle with respect to the center line in the longitudinal direction of the vehicle body.

3 is the semi-trailing arm 1 mentioned above.
and a lateral link 2, the camber control link mechanism includes a first control link 31 and a second control link 32, and the first control link 31 has its base end connected to the semi- It is fixed to the control link fixing part 123 (that is, near the rear wheel support part 121) of the trailing arm 1 with a bolt 33, and the tip extends inwardly and downwardly and forwardly. On the other hand, the second control link 32 is
When setting up the above semi-trailing arm 1
Vertical plane S including the center axis of oscillation l (see Figure 5)
It is arranged in the vertical direction closer to the front of the vehicle body, and its lower end is connected to the first control link 3.
The second control link 32 is rotatably connected to the tip of the second control link 32 via a ball joint 34, and the upper end thereof is rotatably connected to the vehicle body via a ball joint 35. The length is set shorter than the length of the first control link 31.

Furthermore, the second control link 32 is
As shown in Fig. 1, the rotation center point P on the vehicle body side
(Ball joint 35) is installed vertically offset by a set amount e with respect to the swing center axis l of the semi-trailing arm 1.

Reference numeral 4 designates a shock absorber arranged in the vertical direction, and the lower end of the shock absorber 4 is placed on a shock absorber mounting portion 125 that protrudes rearward from the rear end portion of the semi-trailing arm 1, that is, the rear wheel support portion 121. The upper end is connected to the vehicle body. Further, 5 is a coil spring arranged around the outer periphery of the shock absorber 4, and 6 is a rear axle shaft.

Next, to explain the effects of the above embodiment, 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 1, and the base end is swung through a camber control link mechanism 3 consisting of a first control link 31 fixed to the semi-trailing arm 1 and a second control link 32 connected to its tip.

In this case, the camber control link mechanism 3 is configured such that the second control link 32 is located up and down in front of the vehicle body (to the left of the vertical plane S in FIG. 5) from the vertical plane S that includes the swing center axis l of the semi-trailing arm 1. 5, and the rotation center point P (ball joint 35) on the vehicle body side is offset by a set amount e from the swing center axis l of the semi-trailing arm 1. As shown, the first control link 31 and the second
The connection point Q (ball joint 34) with the control link 32 is the semi-trailing arm 1
The rotation locus of rotation around the rotation center axis l of
There is a difference between q ₁ and the rotation locus q ₂ of the second control link 32, which rotates around the rotation center point P on the vehicle body side, especially at the time of a bump where the connection point Q is displaced toward the rear of the vehicle body. , when the bump amount is small, the difference is small, and when the bump amount is large, a relatively large difference occurs. This trajectory difference becomes the amount of camber control (correction amount) for the camber change of the rear wheel W caused only by the swinging of the semi-trailing arm 1, and this camber control amount allows only the swinging of the semi-trailing arm 1 to change. The camber change of the rear wheel W due to
Based on the elastic deformation (4), correction control is performed according to bumps and rebound.

As a result, when the amount of bumps caused by cornering is small, the amount of correction can be reduced to negatively cancel the rear wheel W, and the steering stability during cornering can be improved. Also, on the other hand,
When the amount of bump is relatively large, such as when driving straight, bumps due to rough roads, or rebound, the amount of correction can be increased to keep the camber change of the rear wheel W small, thereby improving straight-line driving performance. .

Moreover, the base end of the semi-trailing arm 1 is attached to the vehicle body at one point via the elastic bush 14, and the vicinity of the tip (lateral link attachment portion 124) is attached to the vehicle body via the lateral link 2. This not only has the advantage that camber control in response to bumps and rebounds can be easily performed with the elastic deformation of one elastic bushing 14, but also has the advantage that camber control in response to bumps and rebounds is easily performed. It has the advantages of increasing lateral rigidity and reducing weight.

Further, the base end of the first control link 31 in the camber control link mechanism 3 is located near the rear wheel support portion 121 of the semi-trailing arm 1 (control link solid portion 12
3), and one end of the lateral link 2 is attached near the control link fixing part 123 of the semi-trailing arm 1 (lateral link mounting part 1).
24), the length of the torsion applied to the semi-trailing arm 1 by the camber control mechanism 3 and the lateral link 2 is shortened, which is effective in improving torsional rigidity and reducing weight accordingly. Become.

In addition, since it is possible to control camber changes according to bumps and rebounds,
The position of the semi-trailing arm 1, the direction of the swing center axis l, etc. can be freely selected so as not to interfere with the vehicle body, and the degree of freedom in designing the rear suspension can be increased.

In the above embodiment, the present invention was applied to a semi-trailing arm type rear suspension having one attachment point on the vehicle body side, but a semi-trailing arm type rear suspension having two attachment points on the vehicle body side was described. Of course, it can also be applied to a full trailing arm type, and in particular, the full trailing arm type is effective for negative camber control of the rear wheel during cornering.

Further, in the above embodiment, the second control link 32 of the camber control link mechanism 3 is
The second control link 32 is arranged vertically in front of the vehicle body from a vertical plane S including the swing center axis l of the semi-trailing arm 1, and the lower end of the second control link 32 is connected to the tip of the first control link 31, and the upper end thereof is connected to the vehicle body. However, conversely, the upper end of the second control link 32 is connected to the first control link 3.
1 and the lower end thereof may be rotatably connected to the vehicle body. In short, the second control link 32 is disposed forward of the vehicle body from the above-mentioned vertical plane S, and its rotational center point on the vehicle body side It is sufficient that P is offset by a set amount from the swing center axis l of the semi-trailing arm 1.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and 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, and FIG. 3 is a rear view of the vehicle as seen from the rear. FIG. 4 is a side view seen from the inside of the vehicle body, and FIG. 5 is a diagram showing the rotation locus of the connection point between the first control link and the second control link. 1... Semi-trailing arm, 121... Rear wheel support part, 14... Elastic bushing, 2...
... Lateral link, 3... Camber control link mechanism, 31... First control link,
32...Second control link, W...Rear wheel, l...Semi-trailing arm pivot axis, P...Rotation center point on the vehicle body side of the second control link.

Claims (1)

[Scope of Claims] 1. A trailing arm that rotatably supports a rear wheel and whose base end is attached to the vehicle body via an elastic bushing so as to be able to swing vertically; and one end of which is attached to the vehicle body side of the trailing arm. A lateral link whose other end is rotatably connected to the vehicle body at a position inside the vehicle body from the attachment point via a ball joint near the rear wheel support portion of the trailing arm, and whose base end is connected to the trailing arm. The second control link includes a first control link fixed to the arm, and a second control link whose one end is rotatably connected to the tip of the first control link and the other end is rotatably connected to the vehicle body. is located vertically in front of the vehicle body relative to the vertical plane that includes the pivot axis of the trailing arm, and its pivot point on the vehicle body side is located a set amount below the vehicle body with respect to the pivot axis of the trailing arm. An automobile rear suspension characterized by being installed offset. 2. The rear suspension for an automobile according to claim 1, wherein the first control link has a base end fixed to the trailing arm near the rear wheel support portion. 3. The trailing arm according to claim 1 or 2, wherein the base end is attached to the vehicle body at one point via an elastic bushing, and the vicinity of the distal end is attached to the vehicle body via a lateral link. Automobile rear suspension. 4. The rear suspension for an automobile according to claim 1, 2, or 3, wherein the trailing arm is arranged so that its pivot axis is inclined with respect to the center line in the longitudinal direction of the vehicle body.