JPS61171604A - Front suspension - Google Patents

Abstract

PURPOSE:To enable a drive performance for cornering to be improved by configurating a front suspension device which has a steering capability, in which a manner that an upper link is allowed to a be composed of a front and a rear links permitting a distance between both upper ends of the links to be set wider than a distance between both lower ends of the links at the wheel side, and the both links are located in the longitudinal direction. CONSTITUTION:An upper link assembly 110 is composed of a front link 111 and a rear link 112, both of which are located facing each other in the longitudinal direction of an automobile. The front link 111 is connected with the rear link 112 by means of ball joints 113 and 114 with an extended section 107 arranged on the upper end of a knuckle spindle 101 in the longitudinal direction. The other ends of the links 111 and 112 are secured apart to a body in the longitudinal direction so that a distance l2 between the ball joints 115 and 116 may be larger than a distance l1 between the ball joints 113 and 114. This configuration enables the upper end of a wheel support member 101 to swing at the time of cornering permitting the caster angle to alter so as to improve a cornering feeling.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a front suspension for a vehicle having a steering function, and more particularly, the present invention relates to a front suspension for a vehicle having a steering function. Regarding the front suspension, which is connected to and supported by the vehicle body via upper and lower links.

The front suspension system with conventional technology, the so-called double-witshubo y deaf suspension, for example, Nirasan Service Bulletin No. 414 (Nissan Motor Co., Ltd. 1982)
Conventionally, there is something like the one shown on page 34 of [Published in April 2013]. That is, as schematically shown in FIG. 9, this front suspension 1 includes a knuckle spindle 30 that rotatably supports the wheel 2, and an upper link 4 and a lower link 5 whose upper and lower ends of the vehicle are oriented in the left-right direction of the vehicle. It is connected to the vehicle body side (not shown). These Acher and lower links 4 and 5 are attached to the knuckle spindle 3 via ball joints 6.7 and enable rotation of the knuckle spindle 3 during steering, as well as elastic bushings 8 and 9.
It is attached to the vehicle body side through the wheel, and is designed to reduce wheel vibrations transmitted to the vehicle body side. Reference numeral 10 designates a knuckle arm that projects integrally from the knuckle spindle 3. This knuckle arm 10 is connected to the side rod 11 of the steering linkage via a ball joint 12t, and when the steering linkage is operated during steering, The knuckle spindle 3 is rotated about a line connecting the ball joys 6 and 7 as a central axis to steer the wheel 2.

Problems that the invention attempts to solve However, such conventional front suspension 1
Ha, aha, lower links 4°5 are placed at the front and rear of the vehicle, respectively, 211! It is supported by the rubber bushing on the vehicle body side and is installed so as to prevent movement in the front and rear directions of the vehicle, so the central axis that rotates the knuckle spindle 3, that is, the line connecting the ball joy y toro and 7t'' is
The preset state is maintained even during steering. Therefore, the caster angle of the front wheels 2 as steered wheels is constant in both the straight-ahead state and when turning, and the camber angle during turning is also determined by the caster angle, so the cornering force limit generated in the wheels 2 is also determined by the caster angle. be done. That is, it is known that the cornering force increases within a certain range as the camber angle, specifically the negative camber angle, increases. However, since the caster angle is set to be smaller by 0.degree. C. based on the straight-ahead condition, the cornering force during turning is also small and slips are likely to occur, resulting in a problem that drivability during cornering deteriorates.

Therefore, the present invention is a front suspension that satisfies the conflicting elements of maneuverability when going straight and increased cornering force when turning by actively changing the caster angle when going straight and when turning. The purpose is to provide the following.

Means for Solving the Problems In order to achieve the above object, the present invention provides a vehicle upper and lower portion of a wheel support member that rotatably supports a wheel and performs wheel steering in conjunction with a steering linkage. In a front suspension that is connected to the vehicle body through an upper link and a lower link that are oriented in the left-right direction of the vehicle, the upper link is composed of a front link and a rear link that face each other in the longitudinal direction of the vehicle. The wheel-side ends of the rear links are rotatably connected to the wheel support members while being spaced apart in the longitudinal direction of the vehicle, and the vehicle body-side ends of the front and rear links are larger than the distance between the wheel-side ends. It is constructed by being rotatably attached to the vehicle body with a distance in the longitudinal direction.

In the front suspension of the present invention with the above-described structure, when the wheel support member is rotated during steering, the lower end of the wheel support member is rotated around one point as in the conventional case. The upper end of the wheel support member is connected to the front and rear links at nine points apart in the longitudinal direction of the vehicle.
While these front and rear links are rotated in the longitudinal direction of the vehicle about the connection point on the vehicle body side, the upper end of the wheel support member is rotated in a twisted manner, and the caster angle is changed. In addition, since the distance between the front and rear links is larger on the vehicle body side than on the wheel support member side, when the caster angle is changed, the inner wheel side is closer to the center of rotation that determines the caster angle. The upper part is tilted forward, and the outer ring side is tilted forward above the rotation center axis. Therefore, when turning,
Both the outer wheels change in the direction of increasing negative camper, and cornering force is increased.

Example Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

That is, FIG. 1 is a schematic diagram of a front suspension 100 showing one embodiment of the present invention. 101 is a knuckle spindle as a wheel support member, and a single wheel 103 is rotatably supported on this knuckle spindle 101 via a spindle portion 102. Further, a side rod 106 of a steering linkage is connected to the tip of a knuckle arm 104 projecting toward the rear of the vehicle from the knuckle spindle 101 via a ball joint 105. In the figure, ball joints are schematically shown using white circles, and rubber bushings are schematically shown using black circles (the same applies below). 110
is an upper link connecting the upper end of the knuckle spindle 101 to the vehicle body side (not shown), oriented in the left-right direction of the vehicle;
A lower link 120 connects the lower end of the knuckle spindle 101 to the vehicle body, similarly oriented in the left-right direction of the vehicle. This lower link 120 is formed into an A-arm shape as in the past, and its tip end is connected to the lower ball joint 1.
211 to the knuckle spindle 101, and the bifurcated base end is connected to the vehicle body via a pair of lower rubber bushes 122, 123. The vehicle body is suspended on the lower link 120 via a suspension spring and a shock absorber (not shown). Further, as shown in FIG. 2, the lower link 120a is composed of one piece, and this lower link 120a is attached to the vehicle body side with one rubber bush 122Jl, and the lower link 120a is attached to the vehicle body side with a tension rod 124 oriented in the longitudinal direction of the vehicle. It may also be of a type that supports

Here, in this embodiment, the upper link 110
is composed of a front link 111 and a rear link 112 that face each other in the longitudinal direction of the vehicle, and an extension part 10 that extends in the longitudinal direction of the vehicle at the upper end of the knuckle spindle 101.
7 are formed in one piece. The knuckle side end of the front link 111 (
The front ball joint 113 is connected to the front ball joint 113, and the rear ball joint 114 is connected to the rear end of the extended portion 107 at the knuckle side end Syk of the rear link 112. . On the other hand, the front line month 11. The end of the rear link 12 on the vehicle body side (the far side in the figure) is connected to the vehicle body side via a front rubber bush 115 and a rear rubber bush 116, which extend 61 tL in the longitudinal direction of the vehicle. At this time, the distance 12 between the front rubber bushing 115 and the rear rubber bushing 116 is set larger than the distance 11 between the front ball joint 113 and the rear ball joint 114, and the front and rear links 111, 112 and the extension part 107 ,
The vehicle body B forms a trapezoidal link structure.

With the above configuration, the functions of the front suspension 1000 of this embodiment will be described based on the operation explanatory diagram of FIG.

In other words, the solid line in the figure indicates a straight-ahead state, and assuming that from this straight-ahead state a right turn is indicated by the broken line in the figure (when the steering wheel (not shown) is turned to the right), the suspension on the left side shown in the figure The rod 106 protrudes and rotates the wheel 103 together with the knuckle spindle 101 to the right with respect to the direction of travel. In this case, the wheel 103 becomes a turning outer wheel. At this time, the lower end of the knuckle spindle 101 is about to rotate at one point around the lower ball joint 121, but the upper end is moved and rotated in a twisted manner. That is, the upper end of the knuckle spindle 101 is connected to the vehicle body side via the front and rear links 111 and 112, and the upper end of the knuckle spindle 101 is connected to the vehicle body side through the front and rear links 111 and 112.
3 and 114 and deformable front and rear rubber bushes 115 and 116 constitute a four-bar link, and in order to rotate one link of the four-bar link, that is, the extension part 107 of the knuckle spindle, it is necessary to The front and rear links 111 and 112 are the rubber bushes 11.
It is rotated around 5,116. Therefore, the upper end of the knuckle spindle 101 is moved and rotated in a twisted manner. By the way, the direction in which the knuckle spindle 101 is moved is the direction in which the front and rear links 11
Since the knuckle spindle 101 side of 1°112 is arranged in a trapezoidal shape, the direction of movement is toward the rear of the vehicle, the front ball joint 113 moves from ao to al, and the rear ball joint 114 moves from bo to bx.
will be moved to . On the other hand, the rotation center X that determines the caster angle of the wheel 103 is determined by the line connecting the midpoint C of the front and rear ball joints 113, 114 and the lower ball joint 121 shown in FIG. , when turning to the right as described above, the center point C moves to point C3 as the knuckle spindle 101 moves backward, and the rotation center line X moves upward as shown by the broken line in FIG. is tilted back and the caster angle is changed. Therefore,
Since the wheel 103 can be regarded as having been steered to the right along the rotation center line XJll that is tilted backward, the wheel 103 on the outer wheel side has a negative camber that changes in one direction.

Note that even when the wheels of the suspension on the right side (not shown) are on the outer wheel side, that is, when the vehicle turns to the left, the outer wheels are changed to the negative camber direction for the same reason.

On the other hand, in FIG. 3, if we assume a left-turning state (when the steering wheel is turned to the left) as shown by the two-dot chain line in the figure from the straight-ahead state, the side rod 106 retracts, and together with the knuckle spindle 101, the wheel 103t-travel direction. Rotate to the left.

In this case, the wheel 103 becomes the inner wheel of the turn. When the wheel 103 is on the inner side in this way, the knuckle spindle 101
The upper end of is moved forward and rotated so as to be twisted. Therefore, the middle point C of the extension part 107 at this time moves to point 02 in FIG. Nine rotation center axis
According to JII, the wheels 103 can be regarded as being steered to the left, and even if the wheel 103 is on the inner wheel side, the negative camber angle is changed to become thicker. When the wheel of the suspension on the stone side (not shown) becomes the inner wheel, that is, when the vehicle turns to the right, the inner wheel is changed to increase the negative camber angle for the same reason.

Therefore, in the front suspension 100 of this embodiment, when turning, the negative camber changes in one direction for both the inner and outer wheels, and the camber characteristic with respect to the steering angle of one wheel 103 is as shown in FIG. Become. That is, wheels are usually equipped with casters such that the upper part of the center axis of rotation X is tilted backward, and in the case of a conventional suspension, a characteristic line A is drawn as shown by a chain double-dashed line in the figure. However, in the eggplant pension 100 of this embodiment,
A characteristic line B as shown by a solid line in the figure is drawn, and it is understood that the negative camber degree is large for both the inner and outer wheels. The characteristic line C shown by a broken line in the figure shows the conventional camber characteristic when the caster is set large, and the characteristic line C shown by a dashed dotted line shows the conventional camber characteristic when the caster is set small.

Therefore, in this embodiment, by increasing the negative camber of the inner and outer wheels during cornering, the conventional cornering force characteristic E
On the other hand, the cornering force characteristic F according to this embodiment shown by the solid line in the figure becomes flat, and the cornering force is increased. Therefore, as the cornering force increases during cornering, the critical turning acceleration to prevent the wheels from slipping, as shown in Figure 7, is lower than that shown by the solid line, compared to the conventional case shown by the two-dot chain line. In the case of the example, the front suspension 10 of this example is thicker, and the drivability during cornering is greatly improved.
At 0, the caster of the wheels is changed in accordance with the steering angle, so the tire lifting torque also increases in accordance with the steering angle. Therefore, as shown in Fig. 8, the acceleration in the vehicle lateral direction (
The steering force characteristic F with respect to lateral G) also approaches a straight line compared to the conventional characteristic H, so a firm steering feeling can be obtained during cornering.

As described in detail of the invention, the 70-ton suspension nearer of the present invention has an upper link composed of a front link and a rear link, and these front links and rear links have a planar trapezoid shape that is narrower on the side of the wheel support member. Since I placed it in
During steering, the upper end of the wheel support member is rotated while moving in the longitudinal direction of the vehicle due to the rotation of the front and rear links. Therefore, the caster of the wheels changes when driving straight and when steering, and when driving straight, it exhibits straight-line performance in the direction of increasing positive camber, and when cornering, it exhibits straight-line performance in the direction of increasing positive camber.

Both outer wheels are changed to increase negative camber, increasing cornering force. For this reason, the slip limit turning acceleration during cornering is large (which greatly improves cornering drivability, and it is possible to prevent spin and significantly improve safety. Furthermore, the steering angle during steering As the caster of the wheels changes accordingly, the steering force can be changed in a nearly linear manner, giving a firmer steering feel during cornering. .

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing one side of a front suspension according to the present invention as an example, FIG. 2 is a schematic configuration diagram showing main parts of another embodiment of the present invention, and FIG. Fig. 4 is an explanatory diagram showing the operation of the front suspension of the present invention, Fig. 5 is a characteristic diagram showing the relationship between the caster angle and camber angle for the inner and outer wheels, and Fig. 6 is a diagram showing the change in cornering force due to the camber angle. Figure 7 is a characteristic diagram showing the limit turning acceleration of slip due to camber angle, Figure 8 is a characteristic diagram showing the relationship between lateral G and steering force, and Figure 9 shows one side of a conventional front suspension. It is a schematic block diagram. 100...Front suspension, 101...Knuckle spindle (wheel support member), 103...Wheel, 110...Upper link, 111...Front link, 112...Rear link, 113... Front ball joint, 114...Rear ball joint/
), 120...lower link, 121...lower ball joint. Other 2 people '・:l Figure 5 Figure 6, Soft Ank 1 deg 1N (IQ;'R? 1i

Claims (1)

[Claims] (1) The vehicle upper and lower parts of the wheel support member, which rotatably supports the wheels and performs wheel steering in conjunction with the steering linkage, are connected to the vehicle body through upper links and lower links that are oriented in the left-right direction of the vehicle. In front suspensions that are now connected to the sides, the upper link consists of a front link and a rear link that face each other in the longitudinal direction of the vehicle, and the wheel side ends of these front and rear links are separated in the longitudinal direction of the vehicle. The front and rear links are rotatably connected to the wheel support member, and the vehicle body side ends of the front and rear links are rotatable toward the vehicle body with a distance in the longitudinal direction of the vehicle that is greater than the distance between the wheel side ends. A front suspension characterized by being attached to.