JPH0399916A - Suspension - Google Patents

Abstract

PURPOSE:To improve comfortableness by installing a shock absorber on an upper part link of the upper and lower part links for supporting wheels capable of vertical fluctuation through a bell crank and by specifying a dimensional relation around it so as to eliminate a force component in the lateral direction acting on the upper link. CONSTITUTION:An upper part link 11 and a lower part link 12 formed as an A arm respectively are placed between a car body 13 and a wheel 14 capable of fluctuation so as to guide the wheel 14 through a wheel supporting member 15. The upper link 11 supports a bell crank 18 in the shape of an almost triangle, and a shock absorber 23 is placed between its first pivot part 20 and the car body 13, and a pair of front and rear pull rods 24 are between a second pivot part 21 of the bell crank 18 and the car body 13, respectively. And when the distances from each of the axes of the shock absorber 23 and the pull rod 24 to a rotation supporting point 19 are l1 and l2 and the inclinations of the shock absorber 23 and the pull rod 24 are theta1 and theta2, it is set so that the relation of costheta1 = (l1 / l2) sintheta2 is established.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicle suspension, and more particularly to a modified pullrond type suspension.

(Prior Art) In general, some vehicle suspensions employ a double link system that is spaced apart in the vertical direction of the vehicle and interposed between the vehicle body and the wheels, and also use a pull rod. (“Motor fan J 1
(See June 987 issue, page 81).

In this pullrond type front suspension, the stroke of the spring 2 and shock absorber 3 relative to the vertical stroke of the wheel l, that is, the so-called lever ratio, is brought close to 1.0, but in order to make it greater than 1.0, the upper link 4 and the shock absorber A pull rod 5 and a bell crank 6 are interposed between the absorbers 3.

Furthermore, there is a front suspension for general passenger cars as shown in FIG. (rAT288(198
6)? / 8 J, page 409). This front suspension is a typical layout example of a spring/shock absorber in the double wishbone type, with the lower end of the shock absorber 8 mounted on the upper link 9, and the approximate lever ratio L from Ll + L2 shown in the figure.
g/L+ (0.7 in the case of the figure).

(Problem to be Solved by the Invention) However, in the conventional suspension as shown in FIGS. 4 and 5, the upper link 4.9 mounts the pull rod 5 or the shock absorber 8, respectively. Since the configuration was such that a preload having a component in the vehicle width direction is applied from It is necessary to increase the bushing capacity to sufficiently withstand these preloads, and in order to ensure ride comfort, it is not possible to use a low-rigidity mount bushing. There was a problem in that it was difficult to set a spring constant.

In addition, the suspension shown in FIG. 4 includes a shock absorber 3, a pull rod 5, and a bell crank 6.
Each pivot point is laid out on a flat surface to suppress the generation of moment, but in the case of a four-wheel drive vehicle, each pivot point is shifted back and forth to avoid interference between the pull rod 5 and the drive shaft (not shown). It is necessary to tilt the pull rod 5 back and forth. In this case, preload in the longitudinal direction of the vehicle is also applied to the upper link 4, so
The mount bushing of the connecting portion 4a needs to be highly rigid in the longitudinal direction of the vehicle, and in addition to the above-mentioned problem, it is even more difficult to set the mount bushing.

(Objective of the Invention) Therefore, the present invention aims to significantly reduce the preload by reducing the vehicle width direction component of the preload applied to the upper link, thereby adjusting the spring constant of the mount bushing necessary to ensure riding comfort. The purpose is to set it to a low value.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a suspension having an upper link and a lower link that are spaced apart in the vertical direction of a vehicle and interposed between a wheel support member and a vehicle body.
A rotation fulcrum part rotatably supported on one of the upper link or the vehicle body around a rotation center axis whose axis direction is the longitudinal direction of the vehicle;
a bell crank having a second pivot part; a shock absorber swingably connected to the vehicle body and the first pivot part; a pull rod swingably connected to the upper link or the other of the vehicle body and the second pivot part; , and the distance from the axis of the shock absorber to the rotation fulcrum is 11
, the distance from the axis of the pull rod to the rotation fulcrum is 12,
The inclination of the shock absorber with respect to the horizontal reference plane of the vehicle is θ5, and the inclination of the pull rod with respect to the vertical reference plane of the vehicle is θ.
When I set it to 2, ! .

It is characterized by having the following relationship.

(Function) In the present invention, the distance from the axis of the shock absorber to the rotation fulcrum of the Pell link is 1, the distance from the axis of the pull rod to the rotation fulcrum is 22, and the inclination of the shock absorber with respect to the horizontal reference plane of the vehicle is θ8, and the inclination of the pull rod with respect to the vehicle's vertical reference plane is θ8. Therefore, the vehicle width direction component of the force acting on the upper link is canceled out, and the preload is significantly reduced, reducing the rigidity value, capacity, etc. of the mount bushing. can be set low. As a result, a spring constant sufficient to ensure riding comfort can be easily set.

(Example) Hereinafter, the present invention will be explained based on the drawings.

FIG. 1.2 is a diagram showing a first embodiment of the suspension according to the present invention, and shows an example in which the present invention is applied to a front suspension. Note that although only one left and right side of the suspension of the vehicle is shown in the figure, it actually has a symmetrical configuration.

First, the configuration will be explained. In FIG. 1, 11 is an upper link, and 12 is a lower link. The upper link 11 and the lower link 12 are swingably interposed between the vehicle body 13 and the wheels 14, are spaced apart in the vertical direction of the vehicle, and support the wheels. The wheels 14 are guided through an axle housing 15 as a member. The upper link 11 and the lower link 12 are each formed as a so-called A-arm, and the pivot parts 11a and 12a on the wheel 14 side are connected to the axle housing 15 via a ball joint (not shown), etc. Pot part is mount bush 16.1
It is connected to the vehicle body 13 via 7. Further, a substantially triangular bell crank 18 is attached to the upper link 11, and the bell crank 18 is rotatably supported by the upper link 11 around a central axis of rotation whose axial direction is the longitudinal direction of the vehicle. and a first pivot portion 20 and a second pivot portion spaced apart from the rotation fulcrum portion 19 toward the inside of the vehicle, respectively.
It has a pivot part 21. Rotating fulcrum part 19 and car body 1
A known shock absorber 23 having a coil spring 22 coaxially attached thereto is swingably interposed between the two parts 3, and a pair of front and rear pull rods 24 are swingably mounted between the second vibond part 21 and the vehicle body 13. is interposed in. Furthermore, the pivot points 20, 21 of the shock absorber 23, pull rod 24, and bell crank 18 are laid out symmetrically on a predetermined plane in order to suppress the generation of moments.

On the other hand, in this suspension, the distance from the axis of the shock absorber 23 to the pivot point 19! 3,
When the distance from the axis of the pull rod 24 to the rotation fulcrum 19 is 1t-, the inclination of the shock absorber 23 with respect to the horizontal reference plane m of the vehicle is 01, and the left and right inclination of the pull rod 24 with respect to the vertical reference plane n of the vehicle is 08. ,.

! .

It is laid out so that it is related.

Next, the effect will be explained.

First, when the reaction force of the shock absorber 23 and the reaction force of the pull loft 24 are each defined as Fl+Fl, the balance of forces applied to the pull rod 24 is shown as shown in FIG. Then, the rotation fulcrum part 19 has a vector F,
A resultant force F is applied to the upper link 11 and the mount bush 16, and a force FH, which is a lateral component of the resultant force F, and a force Fv, which is a vertical component, are applied to the upper link 11 and the mount bush 16. This force Fν is necessary to maintain a balanced attitude between the sprung weight of the vehicle and the wheels 14.

Therefore, in this embodiment, the layout is designed to eliminate the force F, which is the lateral component (or the horizontal force F including the longitudinal component). That is, the distances from the axis of the shock absorber 23 and the axis of the pull loft 24 are respectively l, 1. In this case, the lateral component Fo
In order to prevent this from occurring, it is sufficient to cancel the horizontal force of the reaction force F, , F, as shown below.

The horizontal component forces of Ft and Fz are F(cos θ+=Fxsin θz −−−−−−−(
1) From the moment balance conditions around point A, 1
, + Ft =lt Fg... (2) or more (
1) By eliminating Fl from (2), the above equation (3) shows that when It is constant, it is necessary to increase θ1 as θ2 increases. Further, when θ1 is 0°, that is, the shock absorber 23 is in a horizontal state, sin θg=iz/L, and in this case, when actually laying out each member, it <1. It is necessary to do so, and! As 2 becomes closer to L, θ2 becomes closer to 90'', that is, the pull rod 24 becomes closer to an upright position.

As described above, in this embodiment, by arranging the pull rod 24 and the like so as to satisfy the above formula (3), the lateral preload applied from the rotation fulcrum portion 19 to the upper link 11 can be significantly reduced. Therefore, the rigidity of the mount bushing 16 can be lowered to ensure riding comfort, and the spring constant of the mount bush 16 can be easily set.

FIG. 3 is a diagram showing a second embodiment of the suspension according to the present invention.

In this embodiment, a rotation support part 32 of a bell crank 31 is rotatably supported by a vehicle body 33, and a first pivot part 34 and a second pivot part 35, which are spaced apart from the rotation support part 32, are provided with shock absorbers. 36 and one end of the pull rod 37 are swingably connected to each other, and the pull loft 37
The other end is connected to the upper link 38. Even in this embodiment, the shock absorber 36 or the pull rod 37
The distance from to the rotation support part 32 is '++'t, horizontally for the shock absorber 36 and the pull rod 37,
The slope from the vertical reference plane is 01. When θ2 is assumed, each member is laid out so as to satisfy the following relationship, and the rotation support portion 32 is attached to the vehicle body 33. Therefore, it is possible to reduce the preload of the upper link 38 and eliminate the lateral preload input from the rotation support part 32 to the vehicle body 33, and it is possible to obtain the same effect as in the first embodiment.

(Effects) According to the present invention, the distance from the axis of the shock absorber to the rotation fulcrum of the bell crank is 11, and the distance from the axis of the pull rod to the rotation fulcrum is 1! , when the inclination of the shock absorber with respect to the horizontal reference plane of the vehicle is θ3, and the left and right inclination of the pull rod with respect to the vertical reference plane of the vehicle is 02, it is made to be I, so the lateral force acting on the upper link is As a result, the preload on the upper link's connection to the vehicle body side can be significantly reduced, and the rigidity value and capacity of the mount bushing can be set lower, improving ride comfort. .

[Brief explanation of drawings]

1.2 are views showing a first embodiment of the suspension according to the present invention, FIG. 1 is a front view thereof, FIG. 2 is a view showing the balance of forces at the pivot point, and FIG. 3 is a view showing the balance of forces at the pivot point. 4 is a front view showing the second embodiment of the suspension according to the present invention;
5 and 5 are respectively front views showing conventional examples. 11... Upper link, 12... Lower link, 13... Vehicle body, 15... Axle housing (wheel support member)
,・16...Mount Bush, 18...
... Bell crank, 19 ... Rotating fulcrum part, 20 ... First pivot part, 21 ... Second pivot part, 23 ... Shock absorber , 24...
・Pull rod.

Claims (1)

[Claims] In a suspension having an upper link and a lower link that are spaced apart in the vertical direction of the vehicle and interposed between a wheel support member and the vehicle body, one of the upper link or the vehicle body has an axis that extends in the longitudinal direction of the vehicle. A bell crank having a rotational fulcrum part rotatably supported around a rotational center axis having a direction, and first and second pivot parts spaced apart from the rotational fulcrum part, respectively; a shock absorber that is swingably connected; and a pull rod that is swingably connected to the upper link or the other side of the vehicle body and a second pivot part; l_1, the distance from the axis of the pull rod to the pivot point is l_2, the inclination of the shock absorber with respect to the horizontal reference plane of the vehicle is θ_1, and the inclination of the pull rod with respect to the vertical reference plane of the vehicle is θ_2, cos θ_1 = (l_1/l_2 ) A suspension characterized by having the relationship sin θ_2.