JPS6033109A - Rear suspension for car - Google Patents

Abstract

PURPOSE:To obtain the optimum traveling performance for a various kinds of cars by forming a trailing arm, subframe, lateral link, and the first and the second control links in each prescribed relation, in an independent type suspension apparatus. CONSTITUTION:The subframe connection point A of the second control link 18 is eccentrically set by a set amount (a) with respect to the line X-X connecting the chassis connection point B of a trailing arm 2 and the subframe connection point C of a lateral link 3. The subframe connection point C of the lateral link 3 is positioned lower by the dimension (b) under the rolling center axis Y-Y of a subframe 7 and further positioned over the pitching center axis Z-Z. the optimum traveling performance for a various kinds of cars can be obtained by properly setting the amount of eccentricity (a), length of link 18, the position relation between the connection point A and the connection point D, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the improvement of rear suspensions for automobiles, particularly independent suspension type rear suspensions.

(Prior art) In general, an independent rear suspension for an automobile includes a trailing arm whose front end is attached to the vehicle body in at least two locations so as to be able to swing vertically, and a trailing arm that extends toward the rear of the vehicle body. This configuration has a rear wheel rotatably supported at the rear end, but with this configuration, when a lateral force is applied from the outside to the V-wheel on the opposite side of the turning direction during cornering, the wheel IC problems occur when the vehicle behaves in the toe-out direction and deteriorates turning performance. To solve this problem, conventionally, an assist link is installed between the rear end of the Herre ring arm and the vehicle body, and the link supports the lateral force acting on the rear wheel during cornering, thereby increasing the toe-out in one direction. Actions are being taken to prevent this behavior. Furthermore, according to Japanese Patent Application Laid-Open No. 58-12811, by locating the center of behavior of the rear wheel in the horizontal plane due to lateral force behind the axis of the wheel, the wheel is caused to behave in the toe-in direction during cornering. An invention is disclosed. According to these, the behavior of the rear wheel in the horizontal plane during cornering is improved, and turning performance is improved.

However, in an independent rear suspension,
In addition to the problem of the behavior of the A7 wheel in the horizontal plane as described above, there is the following problem regarding the change in the angle of suspension during bumps and rebounds. In other words, when the trailing arm swings up and down due to the relative vertical movement of the vehicle body and wheels, the pivot axis of the arm (the axis of connection with the vehicle body) is generally tilted backward from the outside of the vehicle body to the inside. In this relationship, when bumping (when the wheel moves relatively upward), the camber angle changes in the direction of negative camber,
In other words, the lower part of the wheel moves outward and the upper part moves inward, and during rebound (when the wheel moves relatively downward) it changes towards positive camber. The direction and amount of change in the camber angle with respect to bumps and rebounds are uniquely determined by the direction of the swing center axis of the trailing arm. Therefore, it is possible to freely set driving performance by changing the camber angle, for example, by reducing the amount of change in the camber angle to improve straight-line stability, or by increasing the negative camber when bumps occur during cornering to improve turning performance. become unable to do so.

(Purpose of the Invention) The present invention addresses the above-mentioned problems with independent rear suspensions, and is a new technology that allows the camber angle change of the rear wheel to be freely set and controlled during bumps and rebounds. The first objective is to realize a suspension mechanism that is suitable for the type of vehicle, usage conditions, etc., and to obtain the optimum driving performance of the IC.

Furthermore, the present invention provides a suspension that enables camber control during bumps and rebounds as described above, and further improves turning performance by configuring the A7 wheel on the opposite side of the turning direction to behave in a negative camber direction during cornering. The second objective is to achieve the expected behavior of the rear wheels without being influenced by the front and rear forces that occur during sudden acceleration, braking, etc. do.

(Structure of the Invention) The R17 suspension according to the present invention is structured as follows in order to achieve the above object.

First of all, the basic structure of this rear suspension is as follows:
``A trailing arm that is connected to the vehicle body at one point via an elastic bushing so as to be able to swing up and down.''-7 Wheels are rotatably supported; a subframe elastically supported by the vehicle body; a lateral link rotatably connected at one end to the subframe and at the other end to the trailing arm to receive lateral forces acting on the rear wheel; and the subtourem. It has a camber control mechanism interposed between the trailing arm and the trailing arm. This camber control mechanism includes a first control link whose base end is fixed to the trailing arm, one end of which is rotatably connected to the tip of the first control link, and the other end of which is rotatably connected to the subframe. a second control link, and the subframe side connection point of the second control link is a straight line connecting the vehicle body side connection point of the trailing arm and the subframe side connection point of the lateral link;
That is, it is provided eccentrically by a set amount with respect to the semi-trailing shaft. According to such a configuration, when the A7 wheel attempts to swing vertically about the semi-trailing shaft during a bump or rebound, the action of the cambercon 1 to the roll 814M causes the small ? - The wheel will be rotated around the camber center axis connecting the vehicle body side connection point and the lateral link connection point in the trailing arm, but in that case, the eccentricity and dimensions of the second control link in the camber control mechanism By appropriately setting the parameters, it becomes possible to freely set and control the direction and intensity of the change in the impingement angle of the 7-wheel with respect to bump and rebound.

Furthermore, in the A7 suspension according to the present invention,
In addition to the above configuration, the subframe side connection point of the lateral link is located below the rolling center axis of the subframe and on the pitching center axis of the one nub frame. Therefore, when cornering, when a lateral force that acts on the 7 wheels on the opposite side of the turning direction is applied to the subframe via the lateral link, the subframe rolls in the direction where the wheel side becomes lower, and the camber control mechanism is activated. Through this, the rear wheel is rotated in the negative camber direction around the camber center axis. Further, the position of the semi-trailing shaft, which serves as a reference for the behavior of the rear wheel as described above, is no longer affected by the pitching movement of the nub frame, so that the rear wheel always behaves as expected.

(Example) Hereinafter, a rear suspension according to the present invention will be described based on an example shown in the drawings.

As shown in FIG. 1, this rear suspension 1 has a trailing arm 2, a lateral link 3, and a camber control mechanism 4 as its main components, and includes a vehicle body 5 and a central portion of the vehicle body 5 that has a trailing arm 2, a lateral link 3, and a camber control mechanism 4. It is supported by the subframe 7 which is elastically supported through elastic bushes 6...6 at four locations.

The trailing arm 2 is arranged at the end of the vehicle body, with its tip end 2a pivotally supported by a bracket 8 fixed to the vehicle body 5 via an elastic bushing 9, and its base end 2b swings in the vertical direction. It is said to be free. Further, the lateral link 3 is installed diagonally between the base end 2b of the trailing arm 2 and the subframe 7, and both ends thereof are - the base end 2b of the trailing arm 2 and the subframe 7. 7
are rotatably connected to each other via pole joins 1 to io and il, respectively. A leaf wheel 12 is rotatably supported on the base end 2b of the trailing arm 2, and the wheel 12 is attached to an axle 14 extending laterally from a differential gear 13 supported by the subframe 7.
The trailing arm base end 21) has an upper end connected to a lower end of a shock absorbing device 15 made of a spring and a damper attached to the vehicle body.

On the other hand, the camber control mechanism 4 has a base end 17a fixed to the base end 2 of the trailing arm 2 by a bolt 16, and extends diagonally forward between the trailing arm 2 and the lateral link 3. The first control link 17 extends from the first control link 17, and the first control link 17 has one end 18a rotatably connected to the brackets I to 19 fixed to the subframe 7, and the other end 18b connects to the first control link 1.
7, and a second control link 18 rotatably connected to the distal end 17b of the second control link 18 disposed in a substantially vertical direction.

As shown in FIG. 2.3, the subframe side connection point A (end 18a) of the second control link 18 in this camber control mechanism 4 is connected to the vehicle body side connection point B (tip 2a) of the trailing arm 2. ) and the subframe side connection point C of the lateral link 3 (ball joint 11
), that is, the semi-1-railing axis x-x, is eccentrically installed by a set amount a (see FIG. 3).

In addition, the subframe 7 has elastic bushings 6 on the front, rear, left and right sides.
・Since it is supported by the vehicle body 5 through the
．． 3, the subframe side connection point C of the lateral link 3 is located below this rolling center axis Y-Y by a dimension b (see FIG. 3), and the pitching center axis z -7.

Here, the subframe side connection point C of the lateral link 3
is the pitching center axis 7 of the predetermined subframe 7
The pitching center axis Z may be set so as to correspond to the pitching center axis Z.
−7 can also be made to coincide with connection point C.

Next, the 1c Hiki 7 suspension 1 constructed as described above
Explain how it works.

First, the relative behavior of the rear wheel 12 with respect to the small body 5 during bumps and rebounds will be explained.
It is supported by the vehicle body 5 and the sub frame 7 attached to the vehicle body 5 via the vehicle body 5, and the vehicle body side connecting point B of the trailing arm 2 and the sub frame side connecting point C of the lateral link 3 are both rotated. Because of its flexible configuration, the wheel 12 tends to swing up and down about the straight line connecting the two points B and C (L trailing axis>X-X).

However, since the camber citrol 8N structure 4 is interposed between the base end 2b of the trailing arm 2 and the subframe 7, the swinging around the semi-trailing axis XX is as follows. It will be corrected. That is, as shown in FIG. 4, when the trailing arm 2 swings in the (A) direction around the semi-trailing axis XX during a bump, the bolt 16.16 is attached to the base end 2b of the trailing arm 2.
The light control 1117b of the first control link 17, which is rigidly connected to the l-railing arm 2, tries to swing in the (b) direction around the axis Since the end 18b of the second control link 18 is connected to the tip 17b of the control link 17, the connection point is the second control link 18.
This is forcibly corrected to swing in the (c) direction around the subframe side connection point. As a result, when the connection point A is located below the semi-trailing axis x-X as shown in the figure, the tip 17b of the first control link 17 is forcibly lifted upward according to the amount of bump. become. Similarly, when the trailing arm 2 swings in the (A') direction during rebound, the first
The control I-roll link tip end portion 17b, which is about to swing in the (opening) direction, is corrected in the (c') direction and is forcibly lifted upward.

The trailing arm 2 has its distal end 2a connected to the vehicle body 5 via the elastic bush 9, and its base end 2b connected to the lateral link 3 via the ball joint 10. Each connection point B with
, E, and connect the S straight line, that is, the camber center axis W-W (second
(See figure) It is in a state where it can be rotated. Therefore, when the tip 17b of the first control link 17 is lifted upward during a bump or rebound as described above, the 1-railing arm 2 and wheel 12 are Rotation in the (d) direction around the axis W-W is applied, and the wheel 12 behaves in the positive dip camber direction.

Here, if the wheel 12 swings around the semi-trailing axis x-X without its trajectory being corrected, for example, as shown in FIG. In the case where the wheel 12 is tilted backward, the wheel 12 behaves uniquely in the negative camber direction when bumping and in the positive dip camber direction when rebounding. However, due to the action of the camber control mechanism 4 as described above, for example, the positional relationship between the subframe side connection point A of the second control link 18 and the semi-trailing axis XX, the amount of eccentricity, or the link 1
8, or connect the first one to the above connection point.
．． By reversing the vertical relationship between the second control link 17 and the connection point of the second control link 17, 18, it becomes possible to freely set the direction and amount of change in the camber angle with respect to the amount of bump and rebound.

On the other hand, the subframe 7 is elastically supported by the vehicle body 5, and the subframe side connection point C of the lateral link 3
is arranged below the rolling center axis Y-Y of the nub frame 7. Therefore, when cornering, a lateral force F is applied from the outside to the rear wheel 12 on the opposite side of the turning direction.
(see Fig. 2), the lateral force F is input to the subframe 7 via the lateral link 3, so that the subframe 7 is forced to move along the rolling axis Y in the direction shown in Fig. 2.
A moment M around Y will act, and the subframe 7 will rotate in the same direction. As a result, the subframe side connection point A of the second control link 18 connected to the camber control mechanism 4 is pushed down enough, and as a result, the trailing arm as shown in FIG. 5(b) 2 or the rear wheel 12 is the above key 1!
The wheel 12 is rotated in the (E) direction around the center axis W--W of the vehicle, and the wheel 12 is rotated in the negative camber direction. In this way, when cornering, the road opposite to the turning direction
When the boiler is in a negative camber state, the grip force of the wheel on the ground increases, thereby improving turning performance.

By the way, the behavior of the rear wheel as described above is basically based on the semi-trailing axis X-x, and
This is realized by the operation of the camber control mechanism 4 with respect to x. Therefore, in order to make the rear wheel 12 behave as expected, the semi-trailing axis
-x needs to maintain a predetermined positional relationship with respect to the vehicle body 5, but the subframe side connection point C of the lateral link 3, which is one reference point of the axis x-X, is elastically supported by the vehicle body 5 and pitches relative to the vehicle body 5 due to torque reaction force during sudden acceleration, braking force, etc. in the front and rear directions, so there is a risk that the position may fluctuate. However, since the subframe-side connection point C of the lateral link 3 is arranged on the pitching center axis Z-7 of the subframe 7, even if the subframe 7 makes a pitching motion from front to back, the connection point C There is no movement, and the behavior of the rear wheel 12 with respect to the semi-trailing axis X--x takes place as expected.

(Effects of the Invention) As described above, according to the present invention, in an independent suspension type rear suspension, it is possible to freely set and control the change in the camber angle of the A7 wheel during bumps and rebounds. . Thereby, the driving performance such as straight-line performance and turning performance can be optimally set according to the type of vehicle to which the suspension is applied, the conditions of use 49, etc. Furthermore, according to the present invention, when cornering, the rear wheels on the opposite side to the turning direction behave in a negative camber direction (turning performance is improved, and the behavior of these rear wheels is also prevented from having an adverse effect during sudden acceleration or braking). It will always be performed as set, without any interference.

Note that the subframe in the present invention is not limited to one that supports the differential gear as in the illustrated embodiment, but may be any frame that is elastically supported with respect to the vehicle body.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show an embodiment of the present invention, and FIG. 1 is a perspective view showing the overall structure of the beam 7 suspension, FIG. 2 is a plan view, and FIG. Figure If-1 is a longitudinal side view cut along the line, Figure 4 is an enlarged side view of the main parts showing the action, Figure
a) and (b) are rear views of the main parts showing the same effect. DESCRIPTION OF SYMBOLS 1... Rear suspension, 2... Trailing arm, 3... Lateral link, 4... Camber control mechanism, 5... Vehicle body, 7... Tsubaki frame,
9... Elastic bushing, 12... Rear wheel, 17
...First control link, 18...Second control link Applicant Toyo Kogyo Co., Ltd.

Claims (1)

[Claims] (1) A trailing arm that is connected to the vehicle body at one point via an elastic bushing so as to be able to swing vertically and rotatably support the rear wheel; a lateral link having one end rotatably connected to the subframe and the other end rotatably connected to the trailing arm, and a base end Bll connected to the trailing arm. a first control link fixed to the ring arm; and a second control, one end of which is rotatably connected to the tip of the first control link, and the other end rotatably connected to the subframe. The link is aligned, and the subframe side connection point of the second control link is installed eccentrically by a set amount with respect to the straight line connecting the vehicle body side connection point of the trailing arm and the subframe side connection point of the lateral link. A rear suspension for an automobile, characterized in that a connection point on the subframe side of the lateral link is located below a rolling center axis of the subframe and on a pitching center axis of the subframe.