JPH064368B2 - Car rear suspension - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear suspension of an automobile, and particularly to a rear suspension of a trailing arm type such as a semi-trailing arm type or a full trailing arm type during bumping and rebounding. Concerning the camber control measures of.

(Prior Art) Conventionally, as such a trailing arm type rear suspension, as shown in JP-A-58-12811, a wheel is rotatably supported and an elastic bush is provided at at least two base ends. Via a semi-trailing arm that is attached to the vehicle body via the
One end is provided rearward of the wheel support portion of the semi-trailing arm and the other end is provided with an assist link rotatably connected to the vehicle body to change the toe-in of the wheel when a lateral force is applied to the wheel. Those configured as are known.

(Problems to be Solved by the Invention) By the way, it is generally known that it is preferable to control the camber change of the wheels in accordance with the running state of the automobile. For example, when turning, the car body rolls due to centrifugal force, so when bumping, the wheel of the turning outer wheel has an appropriate negative camber with a ground camber angle of zero (when the front of the car body is viewed, the upper end of the wheel moves toward the inside of the car body). It is preferable that the vehicle is inclined (inclined state) because the steering stability during turning can be improved. Further, it is preferable to suppress the change in the camber of the wheel to be small at the time of bumping and rebounding on a bad road during straight running because the canvas last can be prevented and the straight running performance can be improved.

However, in the conventional full trailing arm type rear suspension, the camber change does not occur in the wheel during bumping and rebounding. Also, in the case of the semi-trailing arm type, changes in the camber and toe angle of the wheel during bumping and rebound are uniquely determined by the inclination of the semi-trailing axis, and it is compatible with changes in the toe angle. Under the present circumstances, it is impossible to properly control the camber according to the driving condition.

On the other hand, U.S. Pat. No. 3,333,654 and drawings disclose a trailing suspension having a camber control link for correcting camber change. However, in this conventional technology, the camber control link is the swing center axis of the suspension member composed of the trailing arm and the drive shaft (the attachment point of the trailing arm on the vehicle body side and the diff side of the drive shaft). It is located on the front side of the vehicle body with respect to the line connecting the attachment points) and is attached to the vehicle body while being offset upward from the swing center axis line. Therefore, the correction amount by the camber control link is different between when the wheel bumps and when the wheel rebounds. As a result, when turning (rolling) when bump and rebound occur at the same time, the correction amount by the camber control link is different between the left and right wheels, and the camber and toe performance of the left and right wheels are different depending on the roll during turning. is there. Further, since the drive shaft swings due to the diff vibration and the camber control link also swings accordingly, there is a problem that the camber control link promotes the camber change accompanying the diff vibration. Further, since the drive shaft is configured to restrict the lateral displacement of the wheels, the tilt of the swing shaft of the arm is greatly inclined so as to approach the front-rear direction of the vehicle body. There is a problem that the tread change becomes too large, the straight running stability is deteriorated due to this, and the tire is worn. Furthermore, in order to regulate the lateral force entering the wheel,
It is necessary to make the structure of the joint portion of the drive shaft complicated, which increases the cost and makes it difficult to use the constant velocity joint which is generally used in general.

In view of the above, an object of the present invention is to provide a simple configuration in which a camber control mechanism including a link mechanism is installed at an appropriate position in a trailing arm type rear suspension, so that the camber change can be appropriately and stably adjusted according to bumps and rebounds. The camber control is adapted to the running condition, and the correction amount by the camber control mechanism at the time of bumping and rebound is made equal, so that the running stability is especially good when turning. To improve.

(Means for Solving the Problems) In order to achieve the above-mentioned object, a technical solution of the present invention is that a rear wheel is rotatably supported, and a base end of the rear wheel is swingable in a vertical direction on a vehicle body through an elastic bush. A trailing arm attached to the vehicle body, one end of which is located inside the vehicle body with respect to the trailing arm attachment point of the vehicle body, and the other end of which is located near the rear wheel support portion of the trailing arm via ball joints. A lateral link rotatably connected, a first control link whose base end is fixed to the trailing arm, one end rotatably connected to the tip of the first control link, and the other end rotatably connected to the vehicle body. And a second control link provided. The second control link is arranged vertically in a vertical plane including the swing center axis of the suspension member composed of the trailing arm and the lateral link, and the vehicle body side rotation center point thereof is the suspension center. It is assumed that the member is installed with a set amount offset in the vertical direction with respect to the swing center axis line of the member.

(Operation) As a result, the vehicle body side turning center point of the second control link vertically arranged within the vertical plane including the swing center axis of the suspension member configured by the trailing arm and the lateral link is vertically moved. By the offset in the direction, the turning locus about the swing center axis of the suspension member and the second control link at the connecting point of the first control link and the second control link with the same size during bumping and rebounding. There is a difference in the rotation locus about the vehicle body side rotation center point, and this difference in locus becomes the camber control amount (correction amount) of the rear wheel during bumping and rebounding, and the trailing arm swings. Under the elastic deformation of the elastic bushing that constitutes the center point, the equivalent rear wheel key is responded to bumps and rebounds. It is possible to obtain stable changes in the room.

(Advantages of the Invention) Therefore, according to the present invention, the existing trailing arm type rear suspension including the trailing arm and the lateral link is provided with the first control link and the suspension including the trailing arm and the lateral link. A second member arranged vertically in a vertical plane including the swing center axis line of the member and rotatably connected to the vehicle body at a position vertically offset with respect to the swing center axis line.
With the simple structure of adding a camber control link mechanism consisting of control links, the camber change of the wheel can be adjusted appropriately in response to bumps and rebounds and with the same correction amount during bumps and rebounds and stably without being affected by disturbance. It became possible to control. As a result, an appropriate negative camber that makes the ground camber angle at the time of turning traveling to zero becomes possible, the steering stability thereof can be improved, and the camber change at the time of straight traveling can be suppressed to be small and the traveling stability thereof can be improved. Furthermore, since the camber correction amount at the time of bumping is the same as that at the time of rebounding, it is possible to improve the running stability especially during turning running, as compared with the case where the correction amount is different. Therefore, it can greatly contribute to the improvement of driving stability and running stability of an automobile and its easy implementation.

In addition, in the semi-trailing arm type where the camber change is uniquely determined, the camber change can be controlled, which reduces the restrictions on the placement of the semi-trailing arm and increases the design flexibility of the rear suspension. It also has the advantage.

As a method of obtaining an appropriate negative camber, the swing axis of the trailing arm is determined by lateral rigidity, toe angle, or layout requirements. Therefore, when an excessive negative camber is generated, the camber control link mechanism should be used. Correct the camber direction to obtain an appropriate negative camber. Conversely, if the negative camber determined by the tilt of the swing axis is small, correct the negative camber direction by using the camber control link mechanism to obtain an appropriate negative camber. It goes without saying that you should get it.

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

1 to 4 show an embodiment in which the present invention is applied to a semi-trailing arm type rear suspension having one mounting point on the vehicle body side. In the figure, the rear suspension structure for the right rear wheel W is shown.

In FIGS. 1 to 4, reference numeral 1 is a semi-trailing arm arranged substantially in the front-rear direction of the vehicle body. The semi-trailing arm 1 is formed by connecting a front member 11 having a channel shape and a rear member 12 having a substantially cylindrical shape to the front and rear. The rear member 12 includes a cylindrical rear wheel supporting portion 121 that rotatably supports the rear wheel W, and a connecting portion 122 that protrudes forward from the rear wheel supporting portion 121 and is connected to the rear end of the front member 11. , A control link fixing portion 123 protruding inward and forward from the connecting portion 122 and fixed to a base end portion of a first control link 31, which will be described later, and inside the rear wheel supporting portion 121 in the vicinity of the control link fixing portion 123. It has a lateral link mounting portion 124 for projecting toward one side and mounting a lateral link 2 described later. On the other hand, the front member 11 is fixed at its rear end to the connecting portion 122 of the rear member 12 by bolts 13, and its front end (that is, the base end of the semi-trailing arm 1) extends forward, Elastic bush 14 at one point
It is attached to the vehicle body through the through so as to be swingable in the vertical direction.

Reference numeral 2 denotes a lateral link arranged between the semi-trailing arm 1 and the vehicle body. One end of the lateral link 2 is rotatably connected to the vehicle body through a ball joint 21 at a position inward of the vehicle body side mounting point (elastic bush 14) of the semi-trailing arm 1 and the other end thereof is the above-mentioned. Lateral link mounting portion 124 of the semi-trailing arm 1 (near the tip portion, that is, rear wheel support portion 12)
1) is rotatably connected to the rear wheel W via a ball joint 22 to ensure lateral rigidity against a lateral force acting on the rear wheel W. Further, the lateral link 2 and the semi-trailing arm 1 constitute a suspension member that supports the rear wheel W so as to be swingable in the vertical direction with respect to the vehicle body. A straight line connecting both vehicle body side attachment points (the elastic bush 14 and the ball joint 21), that is, the swing center axis line 1 of the suspension member is inclined at a predetermined angle with respect to the vehicle body front-rear direction center line.

Reference numeral 3 denotes a camber control link mechanism which is arranged between the semi-trailing arm 1 and the lateral link 2 and includes a first control link 31 and a second control link 32. The base end of the first control link 31 is fixed to the control link fixing portion 123 of the semi-trailing arm 1 (that is, near the rear wheel support portion 121) by bolts 33, and the tip portion is directed inward and downward. Extends to.
On the other hand, the second control link 32 moves vertically in the vertical plane S (see FIG. 5) including the swing center axis line 1 of the suspension member composed of the semi-trailing arm 1 and the lateral link 2 during setting. The first control link 3 is arranged at the lower end thereof.
1 is rotatably connected via a ball joint 34 to the tip end of 1, and the upper end is rotatably connected to the vehicle body via a ball joint 35. The length of the second control link 32 is set shorter than the length of the first control link 31.

Further, the second control link 32 is installed such that the vehicle body side turning center point P (ball joint 35) is vertically offset with respect to the swing center axis line l of the suspension member by a set amount e. .

In addition, 4 is a shock absorber arranged vertically,
The lower end of the shock absorber 4 is the rear end of the semi-trailing arm 1, that is, the rear wheel support 121.
Is connected to the shock absorber mounting portion 125 protruding rearward from the upper end of the vehicle body. Further, 5 is a coil spring arranged on the outer circumference of the shock absorber 4, and 6 is a coil spring.
Is the rear axle shaft.

Next, the operation and effect of the above-described embodiment will be described. 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 The first control link 3 which fixes the to the semi-trailing arm 1.
It swings via a camber control link mechanism 3 composed of 1 and a second control link 32 connected to the tip thereof.

In this case, the camber control link mechanism 3 is
The second control link 32 is vertically arranged in the vertical plane S including the swing center axis line 1 of the suspension member composed of the semi-trailing arm 1 and the lateral link 2, and the vehicle body side turning center point P thereof. Since the (ball joint 35) is vertically offset with respect to the swing center axis line l of the suspension member by the set amount e, as shown in FIG.
When the vehicle body side rotation center of the rotational locus q ₁ and the second control link 32 which point of attachment to the second control link 32 Q (ball joint 34) is rotated around the swing center axis l of the suspension member The turning locus q ₂ that turns about the point P has the same size during bumping and rebounding. This trajectory difference is
With respect to the camber change of the rear wheel W caused when only the suspension member composed of the semi-trailing arm 1 and the lateral link 2 is swung, assuming that the first and second control links 31 and 32 are not provided. This is the correction amount for all camber controls. In this case, in this embodiment, the camber control link mechanism 3 adds the same amount of positive camber correction during bumping and during rebounding. In other words, the actual camber control amount that takes this correction amount into account is
At the time of bumping and rebounding, it is obtained under elastic deformation of the elastic mounting points (elastic bushes 14) of the semi-trailing arm 1 at the same time. The excessive change in the negative camber direction determined by can be corrected by the camber control link mechanism 3 in the positive camber direction to make the rear wheel W an appropriate negative camber that makes the ground camber angle zero, while the rebound side At the wheel, the change in the positive camber direction determined by the swing axis of the semi-trailing arm 1 is increased by the correction of the positive camber direction by the camber control ring mechanism 3, so that the grip force of the wheel can be increased and the turning It is possible to improve steering stability during traveling. Furthermore, since the camber correction amount by the camber control link mechanism 3 is the same during bumping and during rebound, traveling stability can be improved compared to when the correction amount is different. In addition, it is possible to suppress the camber change of the rear wheel W in the negative camber direction at the time of straight traveling or bumping due to a bad road,
It is possible to effectively improve straight running performance. further,
If the rear wheel W is set so as to be a negative camber when turning, using the difference in the order between the bump amount when turning and the bump when driving on rough roads, the camber when driving straight on bad roads It can act so as to suppress the change to be small, and the above compatibility can be achieved.

Moreover, the semi-trailing arm 1 has its base end attached to the vehicle body at one point via the elastic bush 14 and the vicinity of the tip end portion (lateral link attachment portion 124) attached to the vehicle body via the lateral link 2. Therefore, not only has the advantage that the camber control according to the bump and the rebound can be easily and stably performed with the elastic deformation of one elastic bush 14 and is not affected by the disturbance, and it also acts on the rear wheel W. It is possible to increase the lateral rigidity of the rear suspension with respect to the lateral force generated and to reduce the weight.

Further, since the same camber change can be obtained according to the bump and the rebound as described above, the position of the semi-trailing arm 1, the direction of the swinging central axis l, etc. can be freely selected so as not to interfere with the vehicle body. The rear suspension can be designed more freely.

Further, in the above-described embodiment, the second control link 32 of the camber control link mechanism 3 is arranged in the vertical direction, and the vehicle body side rotation center point P is located above the connection point Q with the first control link 31. Due to the setting, the mounting point of the camber control link mechanism 3 on the vehicle body side can be increased in combination with the relatively short length of the second control link 32, which is advantageous in the layout of the rear suspension and the second control Link 32
The load acting on is in the tensile direction, which is advantageous in strength.

In addition, in the above embodiment, the first control link 31
The base end of is fixed near the rear wheel support 121 of the semi-trailing arm 1 (control link fixing part 123), and one end of the lateral link 2 is near the control link fixing part 123 of the semi-trailing arm 1 ( By connecting to the lateral link mounting portion 124), the length of the semi-trailing arm 1 which is twisted by the camber control link mechanism 3 and the lateral link 2 is shortened, which is effective in improving the torsional rigidity and the weight reduction thereof. Become.

In the above embodiment, the case where the present invention is applied to the semi-trailing arm type rear suspension having one vehicle body side mounting point has been described, but the semi trailing arm type or the full suspension having two vehicle body side mounting points is described. It is needless to say that the same can be applied to the case of the trailing arm type, and in particular, the case of the full trailing arm type is effective for negative camber control of the rear wheel during turning traveling.

Further, in the above embodiment, the second control link 32 of the camber control link mechanism 3 is vertically moved in the vertical plane S including the swing center axis line 1 of the suspension member composed of the semi-trailing arm 1 and the lateral link 2. The lower end of the second control link 32 to the first
The upper end of the control link 31 is rotatably connected to the vehicle body, but conversely, the upper end of the second control link 32 is connected to the tip of the first control link 31.
The lower ends may be rotatably connected to the vehicle body. In short, the second control link 32 is vertically arranged in the vertical plane S, and the vehicle body side rotation center point P thereof is vertically set with respect to the swing center axis line 1 of the semi-trailing arm 1. It just needs to be installed offset.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a schematic explanatory view showing a rear suspension structure for a right rear wheel, FIG. 2 is a plan view of the same, FIG. FIG. 4 is a side view seen from the inside of the vehicle body, and FIG. 5 is a view showing a rotation locus of a connecting point between the first control link and the second control link. 1 ... Semi-trailing arm, 2 ... Lateral link, 1
4 ... Elastic bush, 3 ... Camber control link mechanism, 31 ... First control link, 32 ... Second control link, W ... Rear wheel, l ... Swinging of suspension member composed of semi-trailing arm and lateral link Central axis, P ... Center point of rotation of the second control link on the vehicle body side, S ... Vertical plane.

Claims (1)

[Claims] 1. A trailing arm which rotatably supports a rear wheel and whose base end is swingably mounted on a vehicle body through an elastic bush, and one end of which is a vehicle body side mounting point of the trailing arm. To the car body at a position inward of the car body,
The other end has a lateral link rotatably connected to the rear wheel supporting portion of the trailing arm via a ball joint, a first control link having a base end fixed to the trailing arm, and one end. A second control link, the other end of which is rotatably connected to the vehicle body, is provided at the tip of the first control link, and the second control link is composed of the trailing arm and the lateral link. The suspension member is vertically arranged in the vertical plane including the swing center axis line of the suspension member, and the vehicle body side rotation center point is vertically offset by a set amount with respect to the swing center axis line of the suspension member. The rear suspension of the car, which is characterized by being.