JPH0357709A - Suspension for steering wheel of vehicle - Google Patents

Abstract

PURPOSE:To improve spacing efficiency and on-vehicle property by making a distance between the outer ends of a pair of arms constituting upper and lower arms larger than that between the inner ends and locating the outer end of one arm in straight advance near and outside the extension of the other arm as viewed from above. CONSTITUTION:A lowering system is formed of a compression arm 7 and lateral arm 6 having respectively the outer ends connected pivotably to a knuckle 2 by ball joints GN, AN and the inner ends connected pivotably to a car body by bushings G, A. The ball joint AN is located before and above the ball joint GN and a gap between the outer ends is set larger than a gap between the inner ends. Similarly in a tension arm of an upper link system and a lateral arm 9, the relationship between the outside ball joints R, Q and inside ball joints RN, QN is similarly set. Thus, the on-vehicle property and spacing property are improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a suspension for a steered wheel used in a vehicle such as an automobile.

(Prior Art) Conventionally, as a suspension for steered wheels of a vehicle, one disclosed in, for example, Japanese Unexamined Patent Publication No. 61'-218408 is known.

In this conventional example, the upper link and the lower link, which support the knuckle that rotatably supports the wheel, on the vehicle body are each composed of a pair of front and rear arms, and a virtual kingpin is determined by the instantaneous center point of each link when viewed from above the vehicle body. It is stipulated. Since the virtual kingpin axis is displaced by the movement of the instantaneous center point of each link when the wheels are steered, the caster angle when the wheels are steered can be controlled.

(Problem to be Solved by the Invention) However, in the conventional example described above, the instantaneous center point that defines the virtual kingpin axis (the intersection of the extension lines of each arm viewed from above the vehicle body) is set outside the knuckle in the vehicle width direction. As a result, the knuckles were largely displaced along with the displacement of the virtual kingpin axis (displacement of the above-mentioned intersection point) that occurs when steering the wheels. Therefore, in the conventional example above,
Compared to a general vehicle in which the virtual kingpin axis is fixedly set, the wheel house of the vehicle body must be set considerably larger, resulting in a problem that the overall space efficiency of the vehicle decreases and the ease of mounting on the vehicle deteriorates.

(Means for Solving the Problems) The present invention was devised to solve the above problems, and includes an upper link constituted by a pair of front and rear arms between a knuckle that rotatably supports a wheel and a vehicle body. In a suspension for a vehicle equipped with a lower link system or a lower link system, the pair of arms have their inner ends pivoted to the vehicle body, and their outer ends pivoted to the knuckle, so that the distance between the outer ends is It is set smaller than the distance between the inner ends, and
When the wheels are in the straight-ahead position, the outer end of one arm is located near the extension of the axis of the other arm when viewed from above the vehicle body, and is located further outward in the vehicle width direction than the outer end of the other arm. This is a suspension for steering wheels of a vehicle, which is characterized by:

(Function) According to the present invention, the upper link system or the lower link system is composed of a pair of front and rear arms, and the inner end of the pair of arms is pivotally connected to the vehicle body side, and the outer end is pivotally connected to the knuckle. Since the distance between the outer ends is set smaller than the distance between the inner ends, a virtual kingpin axis is defined by the intersection (instantaneous center point) of the extension lines of both arms as seen from above the vehicle body, and when steering the wheels, this By displacing the instantaneous center point back and forth, the caster angle during steering can be controlled in the same way as in the conventional example.

In the present invention, in particular, when the wheel is in a straight-ahead position, the outer end of one arm is located near the extension of the axis of the other arm when viewed from above the vehicle body, and the outer end of the other arm is positioned in the vehicle width direction. Since it is located outward, when the wheels are steered, only one arm swings a lot while the other arm swings very little, and because the displacement of the outer end of the other arm is small, the knuckle This means less movement.

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

FIG. 1 is a perspective view of a steering wheel suspension according to the present invention, and as shown in FIG.
is rotatably supported. A knuckle arm 3 that projects rearward is formed on the knuckle 2, and a knuckle arm 3 is formed on the knuckle 2. The outer end of a tie rod 4 is pivotally connected to the rear end of the steering wheel 3 via a ball joint H, and the tie rod 4 is connected to an output portion of a steering gear box 5 via a joint T. For this reason, the steering output of the steering gear box 5 is transmitted to the knuckle 2 via the tie rod 4.
The process is done manually.

Between the lower part of the knuckle 2 and the vehicle body, there are a lateral arm 6 arranged substantially in the vehicle width direction, and a compression arm 7 located behind the lateral arm 6 and extending rearward and inward from the knuckle 2 side. A structured lower link system is provided. The outer end of the compression arm 7 is pivotally connected to the lowest part of the knuckle 2 via a ball joint GN, and the inner end of the compression arm 7 is pivotally attached to the vehicle body via a rubber pusher G. On the other hand, the outer end of the lateral arm 6 is pivotally connected to the knuckle 2 via a ball joint ΔN, and this ball joint AN is arranged forward and above the ball joint GN. Also, the inner end of the lateral arm 6 has a rubber pusher A.
The spring constant of the rubber pusher 8 is set larger than that of the comb bush G.

The knuckle 2 is integrally formed with an extension arm 8 that curves and extends above the wheel 1. Between the upper end of the extension arm 8 and the vehicle body, there is a lateral arm 9 arranged in the vehicle width direction, and a tension arm 10 located in front of the lateral arm 9 and extending forward and inward from the knuckle 2 side. An upper link system is provided. The outer end of the lateral arm 9 is pivotally connected to the upper end of the extension arm 8 of the knuckle 2 via a pole joint RN, and the inner end of the lateral arm 9 is pivotally attached to the vehicle body side via a rubber pusher R. On the other hand, the outer end of the tension arm 10 is pivotally connected to the upper end of the extension arm 8 of the knuckle 2 via a ball joint QN, and this ball joint QN is arranged outward in the vehicle width direction from the ball joint RN. There is. Further, the inner end of the tension arm IO is pivotally connected to the vehicle body via a rubber push Q, and the spring constant of the rubber push Q is set smaller than that of the rubber push R.

In FIG. 1, the reference numeral 1l is a drive shaft that transmits the driving force manually applied from the engine to the wheels 1, and the reference numeral 12 is a spring damper unit connected to the vehicle body and the lateral arm 6 of the lower arm system. The lower end of the spring damper unit 12 is formed into a bifurcated shape and connected to the lateral arm 6 in order to avoid interference with the drive shaft 1l.

Figure 2 is similar to Figure l. It schematically shows a plan view,
As shown in Figure 2, in the lower link system, the ball joint AN is the pole joint ｝RN when viewed from above the vehicle body.
It is located further outward and rearward in the vehicle width direction, and the line segment connecting ball joints GN and ΔN is set forward and inward with respect to the traveling direction. In addition, in the lower link system, the intersection of the extended line of the lateral arm 6 and the compression arm 7, which becomes the instantaneous rotation center of the link system and defines the virtual kingpin axis (
The center point between Iljl and KL is located slightly behind the center WO of the wheel 1.

-4. In the upper link system, tension arm 1
The ball joint QN provided at the outer end of the ball joint QN is located on the extension of the axis of the lateral arm 9 when viewed from above the vehicle body, and is positioned outward in the vehicle width direction from the ball joint RN. }The line segment connecting RN and QN is set in the vehicle width direction. Therefore, in the upper link system, the intersection point (instantaneous center point) KU of the extended line of the lateral arm 6 and the tension arm IO, which becomes the instantaneous center of rotation of the link system and defines the virtual kingpin axis, is the ball joint when the wheel is traveling straight. It coincides with the center of QN.

FIG. 3 schematically shows the rear view of FIG. 1, and as shown in FIG. The wheels are set to be inclined inward, and as shown in Figure 1, the kingpin offset at the center W○ of the wheel 1 is set slightly to the positive side, and the kingpin offset at the ground contact surface of the wheel 1 is set to the slightly positive side. It has become a thing.

Furthermore, as is clear from the relationship shown in Figure 2, the virtual kingpin axis KP is set to be tilted backwards, and the first
As shown in the figure, the caster trail on the ground plane is set on the positive side.

Next, the operation of this embodiment will be explained.

First, to explain the basic action of the above suspension, the lower link system is composed of a lateral arm 6 and a compression arm 7, and the upper link system is composed of a lateral arm 9 and a tension arm 10, so that it acts on the wheel 1. The longitudinal force acting on the wheel 1 is supported by the compression arm 7 and the tension arm 10, and the lateral force acting on the wheel 1 is supported by the lateral arm 6.7, so that the force applied to the wheel 1 is efficiently distributed to each arm. It can be supported by

In the lower link system, the spring constant of the rubber pusher 8 is set larger than that of the rubber pusher G, and in the upper link system, the spring constant of the comb bushing R is set larger than the spring constant of the rubber pusher Q. Therefore, the camber rigidity against lateral force is high and stable steering stability is ensured, and at the same time, the rigidity against longitudinal force is set to be relatively low, so the riding comfort when riding over a bump is improved.

In addition, when the wheel 1 is running straight, the virtual kingpin axis KP
is set approximately upright, and the kingbin offset at the ground contact surface of wheel l and the center W○ is extremely small, so that the braking force acting on the ground contact surface of wheel l and the wheel 1
The moment force acting around the virtual king bin axis KP is reduced by the driving force and engine braking force acting on the center WO of .

In addition, the upper link system and lower link system are each 2
Since the virtual kingpin axis KP is set using a real arm, the outer end position of the arm and the kingpin angle can be set individually. Since it is installed above the
The actual length of the upper link system in the vehicle width direction (here, the length of the lateral arm 9 in the vehicle width direction) can be set relatively long, and camber changes and tread changes with respect to the vertical stroke of the wheel are reduced.

Next, the effect when the wheel is steered will be explained based on Fig. 4.5. When wheel 1 becomes the outer turning wheel (in the case shown, when wheel 1 is steered to the right), the lower link system and The Afparalink system will be in the state shown by the dashed line in Figure 4.5. In other words, in the lower link system, as shown in Fig. 4, the line segment connecting the ball joints AN and GN (the lower part of the knuckle 2) is displaced toward the rear of the vehicle and outward, and the momentary center point that defines the virtual king bin axis (The intersection of the extension lines of both arms 6.7 when viewed from above the vehicle body) is KLo, which is displaced backward and inward from the KL point when the vehicle is traveling straight.

On the other hand, in the upper link system, as shown in Fig. 5, the line segment connecting ball joints RN and QN (knuckle 2
The upper end> is displaced inward and behind the vehicle, and the momentary center point that defines the virtual kingpin axis (the intersection of the extension lines of both arms 9 and 10 when viewed from above the vehicle body) is located behind and inward from the KU point when traveling straight. This results in KUo displaced inward.

Further, when the wheel 1 becomes the inner wheel of the turn (in the illustrated case, the wheel 1 is steered to the left), the lower link system and the upper link system are in the state shown by broken lines in FIGS. 4 and 5. In other words, in the lower link system, as shown in Fig. 4, the line segment connecting the pole joins AN and GN (the lower part of the knuckle 2) is displaced inward at the front of the vehicle, and the momentary center that defines the virtual kingpin axis The point becomes KLi, which is displaced forward and inward from the KL point when the vehicle is traveling straight. On the other hand, in the upper link system, as shown in Fig. 5, the line segment connecting ball joints RN and QN (the upper end of knuckle 2) is displaced inward and in front of the vehicle, and the momentary center that defines the virtual kingpin axis The point becomes KLli, which is displaced backward and inward from the point KLt when the vehicle is traveling straight.

As described above, in the outer turning wheel, the lower part of the knuckle 2 is displaced outward and the upper end of the knuckle 2 is displaced inward, so the camber angle of the wheel rotationally supported by the knuckle 2 changes in the negative direction. Therefore, as is clear from Figure 4.5, in the inner wheel of the turn, the inward displacement of the lower part of the knuckle 2 is much larger than the inward displacement of the upper end of the knuckle 2, so the camber angle of the wheel changes in the positive direction. I will do it. As a result, a preferable steering camber change is obtained, and the ground contact of the outer and inner wheels during turning is improved, so the cornering power that can be exerted by the tires is increased, and the turning performance of the vehicle is improved.

This action is achieved by a lateral arm 6 with the lower link system placed approximately in the vehicle width direction and a compression arm 7 placed inward and rearward in the vehicle width direction, and with the upper link system placed approximately in the vehicle width direction. This can be efficiently achieved by constructing the lateral arm 9 arranged in the width direction and the tension arm 10 arranged inward and forward in the vehicle width direction.

Now, to explain the operation of the upper link system in a little more detail, the ball joint R? It is clear from FIG. 5 that the displacement of the line segment connecting QN 1 and QN (the upper end of knuckle 2) is small both when the outer ring turns and when the inner ring turns. That is, in the upper link system, when the wheel 1 is traveling straight, the ball joint QN is connected to the lateral arm 9.
Since it is located on the extension line of , the displacement of the pole join QN during wheel steering is suppressed to a very small extent, and as a result, the virtual king bin axis is defined as described above while suppressing the displacement of the upper end of the knuckle 2. The instantaneous center point Kl can be displaced relatively largely. Further, keeping the displacement of the upper end of the knuckle 2 small means that the displacement of the wheel 1 can be kept small, and thereby the expansion of the wheel house of the vehicle can be suppressed.

Regarding changes in the caster angle, which is the inclination angle in the longitudinal direction of the virtual kingpin shaft, as shown in Fig. 6, the line segment connecting the instantaneous center points of the upper link system and lower link system is measured when the vehicle is viewed from above the vehicle body. The length of the front and rear wheels on the outer wheel side of the turn is almost the same as when going straight ahead, and on the inside wheel side of the turn it increases compared to when going straight ahead, so the caster angle of the outer wheel side of the turn hardly changes, but the caster angle of the inner wheel side of the turn is It will increase. For this reason, as the steering angle increases, the caster angle and caster trail on the inner wheel side of the turn increase, ensuring the steering wheel return force (self-lining torque), while the caster angle when going straight is small, so the steering reaction at the initial stage of steering increases. It is possible to reduce the force and improve the maneuverability of the vehicle.

Here, as a method of increasing the caster angle during steering to ensure the steering wheel return force, it is possible to increase the caster angle on the outer turning wheel side, but in this case, the displacement of the instantaneous center point (KL) of the lower link system It is necessary to increase the displacement of the instantaneous center point (KU) of the upper link system by keeping it small, and in order to keep the displacement of the instantaneous center point (KL) of the lower link system small, the distance between the ball joints AN and GN must be In reality, it is difficult to shorten this distance due to the size of the ball joint, and this method does not provide sufficient effects. Therefore, in this embodiment, the instantaneous center point (
By making the displacement of the ball joint (KL) relatively large to ensure the return force of the handle on the inner ring side of the turn, the distance between the ball joints AN and GN is made to have a margin, increasing the degree of freedom in design. ing.

In addition, as mentioned above, since the handle return force is secured on the inner ring side, the momentary center point (K
l) There is no need to increase the displacement, and the actual length of the upper link system in the vehicle width direction can be set relatively long, so from this point of view as well, it is possible to reduce camber changes and tread changes with respect to the vertical stroke of the wheel. can. In other words, in order to increase the displacement of the instantaneous center point (KU) of the upper link system, the distance between the ball joints RN and QN must be set large, which inevitably shortens the length of the upper link system in the vehicle width direction. As a result, the camber change due to the vertical stroke becomes large, but in this example, the steering wheel returning force is secured on the inner wheel side, so there is no such setting restriction, and the upper link system settings that suppress the camber change are It is possible.

According to the above embodiment, the following effects can be obtained.

First, since the arms that support the longitudinal and lateral forces applied to the wheel 1 are set separately for the upper link system and the lower link system, the force applied to the wheel 1 can be efficiently distributed and supported by each arm. It is easy to set the elasticity of the push provided at the inner end of each arm, and the push that receives lateral force is set hard and the push that receives longitudinal force is set soft, while ensuring the steering stability of the vehicle. This provides the effect of easily maintaining good riding comfort.

In addition, by configuring the upper link and the lower link with a pair of arms, the virtual king pin axis KP
is set approximately upright, and the contact surface and center of the wheel l are 'l/
Since the kingpin offset at VO is extremely small, the moment force acting around the virtual kingpin axis KP is reduced, making it possible to suppress changes in steering force or steering force due to changes in driving and braking forces, and to suppress changes in steering force or steering force due to changes in the road surface. Steering wheel and steering wheel change due to chain attachment. This has the effect of reducing vibrations such as shimmy.

Furthermore, due to the displacement of the upper and lower knuckles in the vehicle width direction during steering, the camber angle changes in the negative direction at the outer turning wheel and the camber angle changes in the positive direction at the inner turning wheel, so that the camber angle relative to the ground changes when the vehicle turns. This has the effect of improving the ground contact of the wheels and improving turning performance.

In addition, since the displacement of the upper part of the knuckle 2 during steering is small, it is possible to suppress the expansion of the wheel house.
It has excellent space efficiency and in-vehicle mountability.

Furthermore, since the caster on the inner wheel side of the turn increases during steering, the steering wheel return force is efficiently ensured, while the caster angle when traveling straight is small, improving the maneuverability of the vehicle.

In addition, since the steering wheel return force is set to be obtained on the inner wheel side of the turn, the displacement of the instantaneous center point of the lower link system can be set to a relatively large value, allowing pole joining.
There is an advantage that it is not necessary to set the distance between GN and AN extremely small, and the arrangement of pole join GN and AN becomes easy.

Furthermore, since the displacement of the instantaneous center point of the lower link system is set to be relatively large in order to obtain the steering wheel return force on the inner wheel side of the turn, the displacement of the instantaneous center point of the upper link system can be set small. Moreover, since the upper link system is installed above the wheel 1, it is possible to set the length of the upper link in the vehicle width direction to be relatively long, which has the effect of reducing camber changes and tread changes with respect to the vertical stroke of the wheel. play.

It should be noted that the present invention is not limited to the above-described embodiment; it goes without saying that various modifications can be made without departing from the gist of the present invention.

(Effects of the Invention) As described above in detail with the embodiments, according to the present invention, it is possible to actively control the caster angle by displacing the virtual king bin shaft during steering, and at the same time Since the movement of the knuckle can be reduced and the expansion of the wheel house can be suppressed, a suspension for steered wheels of a vehicle whose caster angle is controlled in response to wheel steering can be provided without deteriorating space efficiency and vehicle mountability. It has the effect of

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention, 'IIr. 2
The figure is a schematic plan view of Fig. 1, Fig. 3 is a schematic rear view of Fig. 1, Fig. 4 is an explanatory diagram of the operation of the lower link system, Fig. 5 is an explanatory diagram of the operation of the upper link system, and Fig. 6 is a virtual diagram. FIG. 6 is an operation explanatory diagram showing displacement of the kingpin shaft in a plan view. l...wheel, 2...knuckle, 6...lateral arm, 7...compression arm. 9... Lateral arm, 10... Tension arm. KP...Virtual king pin axis ((11-17o) 2 Fig. 1 4 Fig. 5 KIJo

Claims (1)

[Claims] In a suspension for steering wheels of a vehicle, an upper link system or a lower link system consisting of a pair of front and rear arms is provided between a knuckle that rotatably supports the wheel and the vehicle body, and the pair of arms have their inner ends facing the vehicle body. The outer end of one arm is pivotally connected to the knuckle, and the distance between the outer ends is set smaller than the distance between the inner ends, and the outer end of one arm is located above the vehicle body when the wheel is in a straight-ahead position. A suspension for a steered wheel of a vehicle, characterized in that the suspension is located near an extension of the axis of the other arm when viewed from above, and is located outward in the vehicle width direction from the outer end of the other arm.