JPH0362562B2 - - Google Patents

Description

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。そ
して、このように高さhRとhLとが異なると、第
５図から明らかなように、同じバンプ変位量に対
して、右後輪１２Ｒのトーイン量の方が左後輪１
２Ｌのトーイン量よりも小さくなる。したがつ
て、この場合も、前記実施例での説明から明らか
なように、左右の旋回時共に同じようなステアリ
ング特性が得られる。 なお、前述した２つの実施例においては、左右
旋回時のステアリング特性の相違（アンダステア
リング傾向の強さの相違）に応じて、左右のコン
トロールロツド１４Ｒ，１４Ｌの長さlR，lLの
相違、傾斜角度βR，βLの相違あるいは高さhR，
hLの相違の程度が決定されていることは勿論の
ことである。 以上実施例について説明したが、右旋回時の方
が左旋回時よりもアンダステアリング傾向が強い
場合は、前述した長さlR，lL、傾斜角度βR，
βL、あるいは高さhR，hLの関係を左右逆にすれ
ばよい。また、バンプ変位により後輪のグリツプ
力に影響を与えるべく、該バンプ変位した際に左
右後輪にキヤンバ角度の変化が生じるようにする
と共に（ネネガテイブキヤンバが大きくなるほど
グリツプ力が増加する）、キヤンバ角度の変化量
を左右の後輪で異ならせるようにしてもよい。 （発明の効果） 本発明は以上述べたことから明らかなように、
左右の車輪に加わる荷重の相違等により生じる左
右のステアリング特性の相違を打ち消して、左右
同じようなステアリング特性を得ることができ、
自動車の操縦性を向上させることができる。特
に、本発明にあつては、リアサスペンシヨンによ
つて上述したステアリング特性の左右差を打ち消
すので、操蛇輪となる前輪で対処する場合に比し
て制約を受けることが少なく、設計上の自由度の
大きさという観点からも有利となる。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 similar steering characteristics can be obtained when turning left and right. be. (Prior Art) Some automobiles have different left and right steering characteristics due to their structure. In other words, for example, if the understeering tendency is stronger when turning left than when turning right,
FF car (front engine front drive car)
Due to the placement of the heavy engine, the right front wheel load may be greater than the left front wheel load, or the left front drive shaft may be shorter than the right front drive shaft, or FR vehicles (front engine rear drive vehicles) In some cases, the left rear wheel load is greater than the right rear wheel load, or the right rear wheel drive shaft is shorter than the left rear wheel drive shaft. In order to correct this difference in left and right steering characteristics, as shown in Japanese Utility Model Application No. 141805/1985, by making the hardness of the rubber bushing at the attachment point of the lower arm to the vehicle body different on the left and right sides, There are some that cancel out the left and right steering characteristics caused by torque steer. In addition, as shown in Utility Model Application Publication No. 58-73079,
In some models, the pivot axes of the left and right suspension arms for the left and right front wheels, which are used as drive wheels, are set asymmetrically with respect to the vehicle center line to eliminate torque steer caused by the power hop phenomenon during acceleration. . However, in any of the cases described in the above publications, the front wheels are used as the driving wheels, and the torque steer peculiar to automobiles in which the left and right drive shafts are of unequal length is eliminated, and the straight-line stability, especially the drive, is improved. This is only to ensure straight-line stability when the force changes, and it does not completely cancel out the difference in left and right turning characteristics caused by various causes. (Objective of the Invention) The present invention is designed to sufficiently deal with the differences in left and right steering characteristics caused by various causes, and to devise a rear suspension structure so that similar left and right steering characteristics can be obtained. The purpose of the present invention is to provide a rear suspension for automobiles. (Structure of the Invention) In order to achieve the above-mentioned object, the present invention utilizes the bump displacement that occurs on the outer rear wheel when turning, and adjusts the bump displacement when turning to the right and turning to the left. Therefore, the self-steering function that occurs in the outer ring is made to differ. Specifically, the left and right wheel support members are attached to the left and right sides of the rear of the vehicle body so as to be able to swing up and down, respectively, and rotatably support the rear wheels.
When a bump that swings upwards of the vehicle is displaced,
The rear wheels are configured to produce toe or camber wheel angle changes. The wheel support member is asymmetrical on the left and right sides, and the wheel angle is set in a direction that increases the grip force generated on the rear wheel on the outer wheel side of the turn, which undergoes bump displacement during one of the right and left turns where the understeering tendency is stronger. The amount of change in the wheel angle is made smaller than the amount of change in the wheel angle in the direction of increasing the grip force generated on the rear wheel on the outer wheel side of the turn that undergoes bump displacement during the other turn. (Example) First, in the examples described below, it is assumed that the understeering tendency is stronger when turning left than when turning right, and a structure is designed to cancel out the difference in understeering characteristics. It belongs to. Note that the left and right rear wheel suspensions are basically the same structure, so the following explanation will explain the right rear wheel suspension, and the left rear wheel suspension will be explained using the corresponding right rear wheel suspension. The suffix "L" will be used instead of the suffix "R" attached to the constituent elements, and the redundant explanation thereof will be omitted. FIGS. 1 and 2, which show a first embodiment, show the case where the present invention is applied to a suspension that combines a semi-trailing type and a strut type. In FIGS. 1 and 2, a subframe 1 extending in the vehicle width direction is located at the rear of the vehicle body F as a sprung mass.
is fixed, and at the right end of the subframe 1,
The front end of the right semi-trailing arm 2R is rotatably connected. That is, the semi-trailing arm 2R includes two arm parts 3R and 4R, and the front end of the outer end (outer end in the vehicle width direction) side arm part 3R is attached to a support held by the bracket 5R of the subframe 1. With respect to the shaft 6R, and the inner end (inner end in the vehicle width direction) side arm portion 4R with respect to the support shaft 8R held by the flatket 7R of the subframe 1,
Each is rotatably connected. The two support shafts 6R, 8R are arranged on the same straight line, and the axes of the two support shafts 6R, 8R are such that the support shaft 8R is located rearward than the support shaft 6R when viewed from above the vehicle body. It has a swept back angle that is inclined to the vehicle width direction. At the rear end of the right semi-trailing arm 2R, there is a connecting shaft 9R extending substantially in the vertical direction.
The front end of the wheel support 10R is rotatably connected, so that the wheel support 10R
It is rotatable in a substantially horizontal plane about the connecting shaft 9R. The wheel support 10R has a right rear end 12R rotatably held around the spindle 11R. A support shaft 13R extending toward the rear of the vehicle body is protruded from the wheel support 10R, and the outer end of a control rod 14R extending substantially in the width direction of the vehicle is rotatably connected to the support shaft 13R. .
The inner end of the control rod 14R is rotatably connected to a support shaft 15R extending in the longitudinal direction of the vehicle body and held by the vehicle body F. Further, a lower end portion of a hydraulic shock absorber 16R as a strut extending substantially vertically is fixed to the wheel support 10R, and an upper end portion of the hydraulic shock absorber 16R is rotatable around its axis. Connected to F. In addition, 1 in Figure 2
7R is a suspension spring. Here, the left and right control rods 14R, 1
The lengths of the 4Ls are different, and the length lL of the left control rod 14L is longer than the length lR of the right control rod 14R (lL>l).
R). In addition, the left and right control rods 14R,
The inner ends of the left control rods 14L are located higher than the outer ends and are inclined with respect to the horizontal axis H, and the inclination angle βL of the left control rod 14L with respect to the horizontal axis H is as follows. The angle of inclination βR of the right control rod 14R with respect to the horizontal axis H is greater than that (βL>βR). Next, the operation of the first embodiment described above will be explained. Now, if the car turns to the left, the right semi-trailing arm 2R is displaced upward about the support shafts 6R and 8R, that is, the right rear wheel 1, which is the outer wheel, is displaced upward.
A so-called bump displacement occurs in which 2R is displaced upward toward the vehicle body. When this bump displacement occurs, the right control rod 14R is moved by its inner end support shaft 15.
Since it rotates counterclockwise in FIG. 2 about R, the position of its outer end, that is, the support shaft 13R, is displaced to the right side in the figure from the state shown in FIGS. 1 and 2. Therefore, the right wheel support 10R is rotated counterclockwise in FIG. 1 about the connecting shaft 9R, and the right rear wheel 12R is tilted in the toe-in direction. Similarly, when the vehicle turns right, the left rear wheel 12L, which is the outer wheel, undergoes a bump displacement, and the left rear wheel 12L also leans in the toe-in direction. The toe-in amount of the rear wheels 12R and 12L when the bump is displaced (i.e., the control load 14
The amount by which the outer ends of R and 14L are displaced toward the outside of the vehicle body is determined by the amount of displacement of the left and right control rods 1 described above.
Due to the length relationship and inclination angle relationship (at least one relationship) of 4R and 14L, the left rear wheel 12L is larger than the right rear wheel 12R. A large amount of toe-in means that the grip force becomes strong, which increases the tendency for understeering. Therefore, when turning to the right, which originally had a weak tendency to understeering, the amount of toe-in (grip force) of the left rear wheel 12L, which is displaced by the bump, is large, so it is significantly corrected to the side of understeering, but the tendency to understeering is During a strong left turn, the right rear wheel 12R undergoes a bump displacement.
Since the amount of toe-in (grip force) is small, the understeering tendency is only corrected to be slightly emphasized, and overall, the steering characteristics are the same when turning left and right. In addition, the left and right control rods 14R, 14
L may be configured such that only either the length relationship or the inclination angle relationship satisfies the above-mentioned relationship, and in this case as well, similar steering characteristics can be obtained in both left and right turns as described above. 3 and 4 show a second embodiment of the present invention, and the same components as those in the previous embodiment are given the same reference numerals and their explanations will be omitted. In this embodiment, the suspension is a general semi-trailing type, and the wheel support 10 in the previous embodiment is
R, 10L and control rod 14R, 1
Semi-trailing arm 2 without 4L
R, 2L, its spindle 11R, 11
Rear wheels 12R and 12L are rotatably held around L. In this embodiment, the support shafts 6R and 8R, which are the pivot centers of the left and right semi-trailing arms 2R and 2L,
The height relationship between L and 8L is different, and when comparing the heights of the support shafts 8R and 8L from the road surface, the height hR of the support shaft 8R for the right semi-trailing arm 2R is higher than that for the left. Semi-trailing arm 2L spindle 8L
is greater than the height hL (hL

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. When the heights hR and hL are different in this way, as is clear from FIG.
The toe-in amount is smaller than that of 2L. Therefore, in this case as well, as is clear from the description of the above embodiment, similar steering characteristics can be obtained both when turning left and right. In the two embodiments described above, the lengths lR and lL of the left and right control rods 14R and 14L are different depending on the difference in steering characteristics during left and right turns (difference in the strength of understeering tendency). Difference in inclination angle βR, βL or height hR,
Of course, the degree of difference in hL has been determined. Although the embodiments have been explained above, if the understeering tendency is stronger when turning to the right than when turning to the left, the above-mentioned lengths lR, lL, inclination angle βR,
The relationship between βL or the heights hR and hL can be reversed left and right. In addition, in order to affect the grip force of the rear wheels due to bump displacement, the camber angle of the left and right rear wheels changes when the bump displaces (the grip force increases as the negative camber increases). , the amount of change in the camber angle may be made different between the left and right rear wheels. (Effects of the Invention) As is clear from the above, the present invention has the following advantages:
It is possible to cancel out the difference in left and right steering characteristics caused by differences in the loads applied to the left and right wheels, and to obtain similar steering characteristics on the left and right wheels.
The maneuverability of the vehicle can be improved. 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 compared to the case where the front wheel, which is a steering wheel, is used to deal with the problem. This is also advantageous in terms of the degree of freedom.

[Brief explanation of drawings]

FIG. 1 is a plan view showing one embodiment of the present invention. Second
The figure is a rear elevational view of Figure 1. FIG. 3 is a simplified plan view showing another embodiment of the present invention. FIG. 4 is a simplified rear elevational view of FIG. 3. FIG. 5 is a graph schematically showing the action of the rear suspension shown in FIGS. 3 and 4. FIG. 2R, 2L; Semi-trailing arm, 6R,
6L, 8R, 8L; Swing shaft, 12R, 12L;
Rear wheel, 9R, 9L; Connection shaft, 10R, 10L; Wheel support, 14R, 14L; Control rod, F; Vehicle body, H; Horizontal axis, lR, l; Length of tension rod, βR, βL; Inclination of tension rod Angle, hR, hL; Height of the swing shaft.

Claims (1)

[Scope of Claims] 1. Left and right wheel support members attached to the left and right sides of the rear of the vehicle body so as to be swingable in the vertical direction, respectively,
A rear suspension that rotatably supports a rear wheel, and each of the wheel support members is configured such that a toe or camber wheel angle change occurs in the rear wheel due to bump displacement that swings upward of the vehicle body. The amount of change in the wheel angle in the direction of increasing the grip force generated on the rear wheel on the outer side of the turn that is displaced by the bump during one of the left and right turns with a strong tendency to understeering is determined by The left and right wheel support members are asymmetrical so that the amount of change in the wheel angle in the direction of increasing the grip force generated on the rear wheel on the outer side of the turning wheel that is displaced is asymmetrical. rear suspension.