JPS63125414A - Suspension of vehicle - Google Patents

Abstract

PURPOSE:To give a good ride by connecting the parts between the inner ends of suspension links for supporting right and left wheel supporting bodies wit movable members, connecting the part between the pair of front and rear movable with an elastic supporting member, and making the supporting rigidity of said suspension links continuously variable. CONSTITUTION:Right and left bosses 14, 15 as wheel supporting members are supported by a vehicle body 11 via suspension struts in the vertical direction respectively. Parallel links 18-21 as parallel suspension links which extend in the literal direction of body are provided on each part of the vehicle body 11 and radius-rods 22, 23 which extend in the longitudinal direction of body are provided. And, each of bosses 14, 15 is connected to one end part of each of links 18-21 and the rods 22, 23 on each right and left side. The parts between front and rear parallel links 18, 20 and between 19, 21 are connected by connecting links 24, 25 as movable links which extend in the lateral direction of body respectively, and rectangular leaf springs 28, 29 as elastic supporting members are provided between the connecting link 24, 25, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicle suspension, and particularly to a vehicle suspension that utilizes compliance steering to improve the running performance of the vehicle.

(Prior Art) Generally, a vehicle suspension includes an elastic member such as a rubber bush between a wheel support and a suspension arm and between a suspension arm and a vehicle body.
Therefore, when a horizontal force is applied to a wheel, a so-called compliance steer occurs in a vehicle suspension in which the horizontal force deforms the elastic member and steers the wheel. For this reason, a vehicle suspension that improves the running performance of a vehicle by utilizing such compliance steering has been disclosed as a suspension for rear wheels of an automobile, for example, in Japanese Utility Model Application Publication No. 57-141109.

As shown in FIG. 8, this suspension consists of two links 1 and 2 as suspension links that are parallel to each other and extend in the lateral direction of the vehicle body (in the left-right direction in the figure), and these links 1. A wheel support 4 is supported on the vehicle body (not shown) via a single link 3, which also serves as a suspension link, and which extends generally in the front-rear direction of the vehicle body on the front (upper side in the figure) of No. 2. This is a so-called parallel link type suspension, and here, link 1.
Rubber bushes 5 are provided at both ends of the link 2 and at the end of the link 3 on the vehicle body side, and the axis A of the axle is aligned with the axis B of the link 1 on the front side of the vehicle body among the mutually parallel links.

In the conventional suspension configured as described above, when a lateral force P is applied to the rear wheel 6 inward of the vehicle body, only the rubber bushings 5 at both ends of the link 1 are mainly elastically deformed, and only the link 1 is deformed. moves inward into the vehicle body, so the rear wheels 6 are steered toward the toe-in side. Therefore, according to this suspension, for example, when cornering, the outer rear wheel, which is subjected to a lateral force inward of the vehicle body, is moved to the toe-in side using compliance steering in almost proportion to the magnitude of the lateral force. The larger the lateral force, the stronger the tendency to understeer, thereby improving the driving performance of the vehicle, especially the steering stability when turning.

(Problem to be Solved by the Invention) However, in such conventional suspensions, since the support rigidity (modulus of elasticity) of the rubber bushings is constant, when the lateral force is large such as when turning at high speed, If the support rigidity of the rubber bushings is set to be low in order to obtain sufficient wheel steering, the suspension link cannot be supported with sufficient rigidity during mid- to low-speed turns, resulting in insufficient response to steering. was there.

In order to solve this problem, we published Japanese Unexamined Patent Publication No. 61-1511.
Like the suspension disclosed in the publication, multiple liquid chambers are provided in the rubber bushing, and the passages between the liquid chambers are opened and closed by a solenoid-driven valve body.
There is also a suspension in which the support rigidity of the rubber bushing can be selected from two types (high and low), but in this suspension, the above-mentioned problem could not be satisfactorily solved because the change in the support rigidity was not continuous.

The present invention provides a vehicle suspension that advantageously solves the above-mentioned problems by having a configuration in which the support rigidity of suspension links can be continuously changed.

(Means for Solving the Problems) The vehicle suspension of the present invention includes a wheel support, a suspension link whose one end is connected to the wheel support, and a suspension link that is connected to the vehicle body in the longitudinal direction axis and the left and right directions of the vehicle body. a movable member supported to be movable substantially parallel to a plane including an axis and connected to the other end of the suspension link; an elastic support member having a flat cross-sectional shape, the elastic support member extending in a direction perpendicular to the vehicle body, and having a portion connected to the movable member that is spaced apart from the support portion to the vehicle body in the direction of extension thereof; can be rotated about a rotation axis extending in the same direction as the extending direction.

(Function) In such a suspension, when a horizontal force is applied from the wheel support to the suspension link, the horizontal force is transmitted to the elastic support member via the movable member, and the elastic support member moves with the vehicle body support part. This deformation causes the movable member, and thus the suspension link, to move relative to the vehicle body within a plane including the longitudinal axis and the lateral axis of the vehicle body.

Here, since the elastic support member is made flat, when the elastic support member is rotated, its bending rigidity changes continuously, and the amount of movement of the suspension link mentioned above changes for the same horizontal force. Continuously changing.

Therefore, according to the vehicle suspension of the present invention, the steering angle of the wheel (hereinafter referred to as compliance steer angle) caused by movement of the suspension link due to horizontal force such as lateral force or longitudinal force can be controlled by a constant horizontal force. For example, if the elastic support member is rotated in response to an increase in vehicle speed and its bending stiffness is continuously increased, the compliance steer angle can be increased or decreased as the vehicle speed increases. can be increased in a quadratic manner with respect to an increase in
It is possible to achieve both very high levels of good responsiveness to steering when running at medium to low speeds and good steering stability when running at high speeds.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIGS. 1(a) and 1(b) are a schematic plan view and a view along arrow A showing an embodiment in which the vehicle suspension of the present invention is applied to a parallel link type suspension for the rear wheels of an automobile. is the vehicle body, 12.13 is the left and right rear wheels, 14
．． 15 connects those rear wheels 12.13 to axles 14a, 15
The left and right bosses as wheel supports, which are rotatably supported via a, are shown. Further, in FIG. 1(a), the upper side indicates the front of the vehicle body.

Here, suspension struts 16 and 17 are arranged on the left and right sides of the vehicle body 11, and the upper ends of these left and right suspension struts 16 and 17 are supported by the vehicle body 11.
Left and right bosses 14 and 15 are fixed to the lower ends of 7, respectively.

On the left and right sides of the vehicle body 11, parallel links 18.19 and 20.21, which are examples of suspension links and extend in the vehicle body (left and right) direction and are parallel to each other, are provided, respectively. Radius rods 22 and 23, which also serve as suspension links and extend approximately in the longitudinal direction of the vehicle body, are provided, respectively.
Here, the parallel link 18.1 located on the left side of the vehicle body
9 and one end of the radius rod 22 are connected to the left boss 14, and one end of the parallel link 20 and the radius rod 23 located on the right side of the vehicle body are connected to the right boss 15. The other ends of the vehicle bodies 23 on the front side of the vehicle body are respectively connected to and supported by the vehicle body 11. Here, as shown in FIG. 1(a), the left axle 14a is approximately equidistant from the parallel links 18 and 19, and the right axle 15a is approximately the same distance from the parallel link 2.
They are located approximately equidistant from 0°21.

On the other hand, here, below the car body 1, extending in the lateral direction of the car body between parallel links 18 and 20 on the front side of the car body and parallel links 19 and 21 on the rear side of the car body, respectively.
Connecting links 24 and 25 are provided as movable members,
Parallel links 18.20 are provided at both ends of the connecting link 24.
Ball join the other end located inside the vehicle body) 26
．． 26 respectively, while the connecting link 25
The other ends of the parallel links 18 and 20 inside the vehicle body are respectively connected to both ends of the parallel links 18 and 20 via ball joints 26 and 26, respectively.

These connecting links 24, 25 are supported on the underside of the vehicle body 11 via two rubber bushings 27, 27 in each case, so that here the connecting links 24, 25, under elastic deformation of the rubber bushings 27, 27, Parallel to the plane including the longitudinal axis of the vehicle body and the lateral axis of the vehicle body, that is, in the lateral direction of the vehicle body, as shown by arrow B in FIG. It is possible to move relative to the Note that arrow C in FIG. 2 indicates the front of the vehicle body.

Furthermore, leaf springs 28 and 29 having a rectangular cross section are provided between the connecting links 24 and 25 as elastic support members. These leaf springs 28.29
As is clear from FIG. 2, the central axis is aligned with the central axis of the rotating shaft 30 located between the leaf springs 28 and 29, and the width directions are twisted by 90 degrees to each other. The ends facing each other are integrally connected to both ends of the rotation shaft 30, and extend together with the rotation shaft 30 in the longitudinal direction of the vehicle body, that is, in the direction orthogonal to the extending direction of the connecting links 24 and 25. Here, the rotation shaft 30 is supported on the lower surface of the vehicle body 11 via a metal bush 31 and a bracket 32, while the other ends of the leaf springs 28 and 29 are supported via a shaft provided there. Connects to connecting links 24 and 25. As a result, the leaf springs 28 and 29 become
They can be rotated about their central axes as shown by the arrows in the figure.

In the suspension configured as described above,
For example, when an automobile turns to the left, a horizontal force outwards from the vehicle body is applied to the inner rear wheel 12 and an outer rear wheel 1 is applied to the inner rear wheel 12.
The horizontal force applied to 3 inward of the vehicle body is the parallel link 1
In addition to the connecting links 24 and 25, the ends of the leaf springs 28 and 29 connected to the connecting links are biased toward the left side of the vehicle body through the connecting links 8 to 21, respectively.

At this time, as shown in FIG. 1, the leaf spring 28 is oriented so that its width direction is perpendicular to the extending direction of the connecting link 24, and therefore, the leaf spring 29 is oriented so that its width direction is perpendicular to the extending direction of the connecting link 24.
If the temporary spring 28 is oriented in the same direction as the
The elastic modulus of the plate spring 29 in the lateral direction of the vehicle body becomes the minimum, and the rigidity of supporting the connection link 24 in the lateral direction of the vehicle body by the leaf spring 28 becomes the minimum. Since the rigidity of the connecting link 25 to support the vehicle body in the lateral direction is maximum, the connecting link 24 moves largely to the left of the vehicle body, while the connecting link 25 hardly moves or does not move at all. Only the links 18 and 20 move to the left of the vehicle body, the rear wheel 12 is largely steered toward the toe-out side, and the rear wheel 13 is largely steered toward the toe-in side. Therefore, when the leaf springs 28, 29 are placed in the rotational position as described above, the compliance steer angle of the rear wheels 12, 13 becomes large in the turning direction for a given horizontal force, and as a result, The tendency to understeer becomes extremely large.

On the other hand, during the above-mentioned turning, the leaf springs 28 and 29 are
If the width directions of the leaf springs 24 and 25 are rotated at an angle of 45° with respect to the extending direction of the connecting links 24 and 25, the elastic modulus of the leaf springs 28 and 29 in the transverse direction of the vehicle body will be equal to each other. Links 24 and 25 move to the left of the vehicle by equal distances so that neither rear wheels 1.2.13 are steered to either side.

Therefore, in this case, even for the same horizontal force as in the above case, the compliance steering angle becomes substantially zero, the understeer tendency disappears, and the vehicle becomes neutral steered (the influence of the front wheels is ignored here). In addition, leaf spring 28.
29 is further rotated from the 45@ position as shown in FIG.
If it is made larger than that of 9, an oversteer tendency will occur, contrary to the first case.

Changes in the compliance steering angle based on the rotational positions of the leaf springs 2B and 29 occur in the same way as in the case described above when the automobile turns to the right. When the car is rotated from the rotation position shown in Figure 1 to the rotation position shown in Figure 2, the steering performance of the car changes from understeer to neutral steer to oversteer for the same horizontal force. Change.

Moreover, the change in the compliance steer angle for the same horizontal force here occurs continuously in response to the rotation of the leaf springs 28, 29, as is clear from the above-mentioned action.

Therefore, according to the suspension vehicle of this example, depending on the traveling speed (vehicle speed) of the automobile, the leaf spring 28
．． 29 to the above-mentioned 45" rotation position, and when turning at high speed, the leaf springs 28 and 29 are brought closer to the rotation position not shown in Fig. It is possible to achieve both very high levels of good responsiveness to steering at medium and low speeds and good steering stability at high speeds.

In this embodiment, in order to control the rotational position of the leaf springs 28 and 29 as described above, a lever 33 is further provided protruding from one end of the rotation wheel 30 as shown in FIGS. The tip of the lever 33 is connected to a leaf spring drive device 34 provided on the lower surface of the vehicle body 11 via a connecting rod 35.

The leaf spring drive device 34 here can be configured with a single-acting hydraulic cylinder 36, for example, as shown in FIG. An oil pump 37 driven by the automobile engine is connected to the hydraulic cylinder 36 in a liquid chamber on the opposite side from the piston rod 36a.
The high pressure side hydraulic oil passage 38 from the oil pump 37 is connected to the piston rod side liquid chamber of the hydraulic cylinder 36, and the low pressure side hydraulic oil passage 39 from the oil pump 37 is connected to the reactivation oil passage 38.39.
are communicated via a control valve 40 operated by a current proportional solenoid, while a well-known vehicle speed sensor 41 is provided in the vehicle body 11, and the output signal of this vehicle speed sensor 41 is transferred to a frequency-voltage converter (F/ν converter). ) 42 and a voltage-to-current converter (V/1 converter) 43, and a current that increases as the vehicle speed increases from the control device 44 is inputted to the control valve 40 described above. to the solenoid.

According to this configuration, as shown in FIG.
9 can be increased, thereby increasing the rotation angle of K
The value of (=vehicle body lateral support rigidity of the connecting link 25/vehicle body lateral supporting rigidity of the connecting link 24) is increased in proportion to the increase in vehicle speed V, and the above-mentioned compliance steer angle appropriately corresponds to the traveling speed. Change can be achieved.

FIG. 5 shows a step motor 45 as the leaf spring drive device 34.
In this case, the step motor 45
The connecting rod 35 connected to the crank 46 is driven by rotating the crank 46 directly or via a reduction gear by the output shaft of the crank 46 . And here, vehicle speed sensor 4
The output signal from 1 is inputted to a control device 47 composed of, for example, an ordinary microcomputer, and the step motor 45 is driven and controlled by this control device 47.

Even with this configuration, as shown in Fig. 4, it is possible to provide an upper limit to the value of K that is proportional to the increase in vehicle speed. It is possible to realize changes corresponding to the changes.

FIG. 6 shows still another embodiment of the present invention using only one leaf spring. In this example, the suspension has a link configuration similar to that shown in FIG. Link 19゜Connect only 21 Link 25
A leaf spring 48 is connected to the connecting link 25 and extends in a direction perpendicular to the connecting link 25 by being integrally connected to one end of the rotating shaft 30. 30 is rotatably supported on the vehicle body via the bush 31 and bracket 32 described above. On the other hand, the parallel links 18, 20 on the front side of the vehicle body are supported on the vehicle body via rubber bushes.

Also in this example, by rotating the leaf spring 48, the vehicle body lateral support rigidity of the connecting link 25 can be continuously changed, so that the same effects as in the example shown in FIG. 1 can be brought about.

FIG. 7 shows yet another embodiment in which the present invention is applied to a front wheel suspension. Knuckle arm 51a, 5
2a is connected to both ends of a tie rod 56 of a steering gear device 55 as a movable member via a tie rod 53, 54 as an example of a suspension link, and the gear box of the steering gear device 55 is also a movable member. 57 is supported on the vehicle body 11 via rubber bushes 58, 58 so as to be movable in the lateral direction of the vehicle, and is connected to one end of the rotation shaft 30 to the gear box 57, as in the example shown in FIG. The rotary shaft 30 is rotatably supported on the vehicle body via a bush 31 and a bracket 32.

According to this example, the compliance steering angle of the left and right front wheels 49,50 can be continuously changed with respect to a constant horizontal force, and the same effect as the example shown in FIG. 1 can be brought about.

Although the present invention has been described above based on the illustrated examples, the present invention can also be implemented in modes other than the above-mentioned examples. For example, a hollow member with an elliptical cross-sectional shape may be used as the elastic support member. Alternatively, for example, a movable member extending approximately in the longitudinal direction of the vehicle body may be connected to the radius rods 22 and 23 in the suspension shown in FIG. We support and
By continuously changing the supporting rigidity of the movable member in the longitudinal direction of the vehicle body using an elastic support member as shown in Fig. 6.7, the compliance angle of the wheel due to the force in the longitudinal direction of the vehicle body as a horizontal force can be changed. Furthermore, it can also be applied to semi-trailing arm type suspensions.

The elastic support member may be rotated manually to adjust the rotational position.

(Effects of the Invention) Thus, according to the vehicle suspension of the present invention, the compliance steer angle due to horizontal forces such as lateral force and longitudinal force can be continuously increased or decreased with respect to a constant horizontal force. For example, by appropriately rotating the elastic support member as the vehicle speed increases, it is possible to achieve an extremely high level of both good responsiveness to steering when driving at medium to low speeds and good steering stability when driving at high speeds. can be achieved.

[Brief explanation of the drawing]

FIG. 1(a) shows the first suspension of the vehicle suspension of the present invention.
1(b) is a schematic plan view showing an example of the embodiment of FIG.
FIG. 3 is a configuration diagram showing an example of the leaf spring drive device and its control device in the example shown in FIG. 1; FIG. 6 is a characteristic diagram showing the operating characteristics of the example device shown in FIG. 1 using the leaf spring drive device and its control device; FIG. 5 is a configuration diagram showing another example of the leaf spring drive device and its control device; 7 and 7 are schematic plan views showing second and third embodiments of the present invention, respectively, and FIG. 8 is a plan view showing a conventional example partially in section. 11...Car body 14.15...Boss 1
8, 19.20.21...Parallel link 24, 25
... Connecting link 28.29 ... Leaf spring patent applicant Nissan Motor Co., Ltd. Figure 6 Figure 7

Claims (1)

[Claims] 1. A wheel support, a suspension link whose one end is connected to the wheel support, and a suspension link supported by a vehicle body so as to be movable substantially parallel to a plane including a longitudinal axis and a lateral axis of the vehicle body. a movable member connected to the other end of the suspension link; an elastic support member having a flat cross-sectional shape and whose portions spaced apart in the extending direction are connected to the movable member; the elastic support member has a rotation axis extending in the same direction as the extending direction; A vehicle suspension that can rotate around the center.