JPH05169940A - Suspension device of vehicle - Google Patents

Abstract

PURPOSE:To improve degree of freedom as for caster control and camber control by arranging the axis of the bush of the upper fitting part of an upper arm so as to be inclined against the axis of the bush of the base end fitting part of a lower arm. CONSTITUTION:The bush of the base end fitting part of a lower arm 50 and the bush of the upper fitting part of an upper arm 40 are respectively constituted so as to have the axes B, C in the longitudinal direction of a vehicle body, and the axis C of the bush of the upper fitting part is arranged to be inclined against the axis B of the bush of the base end fitting part. In case of bumping or rebound, caster angle is changed according to oscillation of the upper arm 40 itself. Therefore, the degree of freedom for caster control and camber control can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle suspension system, and more particularly to a suspension system for a vehicle, which comprises an upper arm, a lower arm and a shock absorber. The present invention relates to an axial center of a bush of a pivotally mounted portion that is arranged to be inclined with respect to an axial center of a bush of a proximal end pivotal portion that pivotally mounts a base end portion of a lower arm to a vehicle body.

[0002]

2. Description of the Related Art Conventionally, strut suspensions and double wishbone suspensions have been widely put into practical use as vehicle suspension devices, but strut suspensions have a small number of parts and have a small and simple structure. There are problems such as increased kingpin offset and difficulty in increasing camber rigidity, and the double wishbone suspension has
Although there is a high degree of freedom in geometrical design for changes in camber and tread, and the kingpin offset can be made relatively small, there is the problem that a large installation space is required. Therefore, as a suspension combining the advantages of both types of suspensions, Japanese Patent Laid-Open No.
-128207, JP-A-57-209408, and JP-B-58-55921 include an upper arm and a lower arm in the vehicle width direction, and a shock absorber, and the lower end of the shock absorber body is pivotally attached to the lower arm. In addition, a suspension device has been proposed in which the inner end of the upper arm is pivotally attached to the shock absorber body.

In the suspension device described in the above publication (hereinafter referred to as strut-improved suspension device), the degree of freedom in the arrangement of the kingpin shaft, the degree of freedom in the camber change, the tread change, and the anti-dive geometrical doubleness are the same as those of the conventional double. It is obtained like a wishbone suspension, is relatively compact, and has excellent layout characteristics, so it is particularly suitable for the front suspension of recent FF vehicles. FIG. 8 shows a mechanical diagram of the strut-improved suspension device.
Is pivoted to the shock absorber 120, the lower end of the shock absorber body is fixed to the lower arm 150 in order to restrict the rotation of the shock absorber 120 in the b direction.
The shock absorber 120 is pivoted at a pivotal portion having a substantially longitudinal axis (Z axis) in the middle of the axis of the shock absorber 120, and the lower shock absorber 150 swings around the X axis in the a direction during bumping or rebounding. Stretch in the direction. The axial center of the bush of the base end pivot portion (X) that pivotally attaches the base end portion of the lower arm 150 to the vehicle body.
The axis controls the pitching center height and affects the anti-dive geometry.

On the other hand, the Y axis of the shock absorber influences the caster angle, and affects various alignments such as roll center height, pitch center height and damper efficiency. Therefore,
The angle between the Z axis, which is substantially parallel to the X axis, and the Y axis is set to an angle α that is not 90 degrees, and not only the angle α changes when bumping or rebounding, but the angle β also increases or decreases. .. At the time of bumping or rebounding, the vertical movement amount of the shock absorber body (that is, the vertical movement amount of the inner end portion of the upper arm 140) becomes smaller than the vertical movement amount of the wheel 100, so that the inclination angle of the upper arm 140 increases. Is configured. Here, in the suspension device of the above publication, the technical idea of performing caster control and camber control through the positional relationship between the W axis and the X axis of the bush of the pivot portion that pivotally attaches the upper arm to the shock absorber body. Is not included at all.

[0005]

In the suspensions disclosed in the former two publications, as shown in FIG. 8, the amount of rise of the lower end portion of the shock absorber during bumping is the amount of rise of the wheel × (n / Therefore, the inclination angle of the upper arm is increased, and an appropriate camber change in which the camber angle becomes a negative value can be secured. By the way, when the X-axis and the W-axis in FIG. 8 are set to be parallel to each other, the caster and the camber can only be controlled through the swing of the upper arm accompanying the ascent and descent of the shock absorber. There is a problem that the casters and camber cannot be changed, and the degree of freedom in caster control and camber control cannot be increased.

An object of the present invention is to provide a vehicle suspension system which can increase the degree of freedom in caster control and camber control.

[0007]

A vehicle suspension device according to a first aspect of the present invention includes an upper arm, a lower arm, and a shock absorber. The lower end of the shock absorber is connected to the lower arm and the upper arm is pivotally attached to the shock absorber body. In the suspension device, the bush of the base end pivot portion pivotally attaching the base end portion of the lower arm to the vehicle body and the bush of the upper pivot attachment portion pivotally attaching the upper arm to the shock absorber body are respectively provided with shafts substantially in the longitudinal direction of the vehicle body. It is characterized in that it is configured to have a core, and the axial center of the bush of the upper pivotally attached portion is arranged to be inclined with respect to the axial center of the bush of the proximal end pivotally attached portion.

According to a second aspect of the present invention, there is provided the vehicle suspension device according to the first aspect, wherein the axial center of the bush of the upper pivotally attached portion is viewed from the side of the vehicle body with respect to the axial center of the bush of the proximal end pivotally attached portion. It is characterized in that it is arranged in an inclined shape.

According to a third aspect of the present invention, there is provided a vehicle suspension device according to the first aspect, wherein the axial center of the bush of the upper pivotally attached portion is viewed in plan view with respect to the axial center of the bush of the proximal end pivotally attached portion. It is characterized in that it is arranged in an inclined shape.

[0010]

In the vehicle suspension device according to the first aspect of the present invention, the bush at the base end pivotal attachment portion of the lower arm and the bush at the upper pivotal attachment portion of the upper arm are each configured to have an axis substantially in the longitudinal direction of the vehicle body. At the same time, since the axial center of the bush of the upper pivot portion is arranged to be inclined with respect to the axial center of the bush of the proximal pivot portion, the caster angle changes according to the swing of the upper arm itself during bumping or rebound. .. Therefore, the degree of freedom in caster control and camber control can be increased.

In the vehicle suspension device according to the second aspect of the present invention, the same operation as that of the first aspect can be obtained, and the axial center of the bush of the upper pivotally attached portion is made to be the axial center of the bush of the base end pivotally attached portion. On the other hand, the caster control action can be enhanced because the vehicle is laterally arranged so as to be inclined.

In the vehicle suspension device according to the third aspect, the same effect as that of the first aspect can be obtained, and the axial center of the bush of the upper pivotally-attached portion is set to the axial center of the bush of the base-end pivotally-attached portion. On the other hand, since they are arranged so as to be inclined in a plan view of the vehicle body, the caster control action can be suppressed and the camber control action can be enhanced.

[0013]

As described in the above section, the following effects can be obtained. According to the vehicle suspension device of the first aspect, the caster is arranged by arranging the axis of the bush of the upper pivot portion of the upper arm in an inclined manner with respect to the axis of the bush of the base pivot portion of the lower arm. The degree of freedom of control and camber control can be increased.

In the vehicle suspension device according to the second aspect, the same effect as that of the first aspect can be obtained, and the axial center of the bush of the upper pivotally connecting portion is made to be the axial center of the bush of the base end pivotally attaching portion. On the other hand, the caster control action can be enhanced by arranging the casters so as to be inclined in a side view of the vehicle body.

In the vehicle suspension device according to the third aspect, the same effect as that of the first aspect can be obtained, and the axial center of the bush of the upper pivotally connecting portion is made to be the axial center of the bush of the proximal end pivotally attaching portion. On the other hand, the camber control action can be enhanced by arranging them in an inclined shape in a plan view of the vehicle body.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. This embodiment is an example of applying the present invention to a front suspension device of an FF type automobile,
Since this suspension device FS has a symmetrical structure,
The structure for supporting the right front wheel 1 will be described below with reference to FIGS. A front side frame 4 is provided on a wheel apron 3 of the engine room 2, a connecting bracket 5a of a suspension cross member 5 is fixed to the front side frame 4 with bolts 6, and a top portion of a suspension tower 7 formed on the wheel apron 3 is provided. A mount portion 8 that connects the shock absorber 20 is provided in the. The suspension device FS includes a wheel support 10, a shock absorber 20, a coil spring 36 arranged outside thereof, an upper arm 40, an I arm 50 as a lower arm, a trailing link 60, a stabilizer 70, and the like. ing.

The wheel support 10 includes a shaft 11 rotatably mounted for mounting the wheel 1a,
A knuckle 12 to which a tie rod 16 of the steering device is connected, an upper pivoting portion 13, and lower pivoting portions 14 and 15 provided close to each other in the front-rear direction are provided, and the right end portion of the driving shaft 9 forms a universal joint. It is connected to the shaft portion 11 through.

With respect to the shock absorber 20 and the coil spring 36, the shock absorber 20 is composed of a general hydraulic damper, and is located near the upper end of the spring receiving member 22 fixed to the shock absorber body 21 and the rod 23 of the shock absorber 20. A coil spring 36 is arranged between the fixed spring receiving members 24, and
Mount member 25 fixed to the upper end of
It is being fixed with four bolts 8a. The lower half of the shock absorber body 21 is composed of a fork member 26 having a pair of front and rear legs 27.
The lower end portion 27a of the I-arm 5 at the first pivot portion 28 is
It is rotatably pivotally attached to the middle portion of 0, and on the outer side of the upper end portion of the fork member 26, at the second pivot portion 29 (which corresponds to the upper pivot portion), the front and rear sides of the upper arm 40 1
The inner ends 42 of the pair of arms 41 are pivotally mounted via a ball joint bush (which includes a shaft-shaped ball joint and a rubber bush). With respect to the first pivotally connecting portion 28, a shaft member having a longitudinal axis of the vehicle body is inserted through a cylindrical portion 51 at a portion near an outer end of the I-arm 50, and a pair of fork members 26 is provided at both ends of the shaft member. The lower end portion 27a of the leg portion 27 is pivotally attached via a rubber bush having an axis A set in the vehicle front-rear direction and having an appropriate hardness.

The I arm 50 will be described.
The arm 50 is arranged substantially horizontally in the vehicle width direction, and an inner end portion 52 (base end portion) of the arm 50 has a ball joint bush having a shaft center B oriented in the vehicle body front-rear direction (axial ball joint and rubber bush. Is included in the suspension cross member 5, and the outer end portion 53 of the I-arm 50 is pivotally connected to the front lower pivot portion 14 by a ball joint. The axis A and the axis B are parallel to each other and are set in the longitudinal direction of the vehicle body. However, the axis A and the axis B may be arranged to be slightly inclined with respect to the longitudinal direction of the vehicle body. The upper arm 40 will be described.
Are arranged substantially horizontally in the vehicle width direction, and the pair of arms 4
As described above, the inner end portion 42 of No. 1 has an axial center C that is substantially peeled in the front-back direction.
Fork member 26 via a ball joint bush having
Is pivotally attached to the outer pivot portion 30 at the upper end of the upper arm 4
The outer end portion 43 of 0 is pivotally attached to the upper pivot portion 13 by a ball joint. Here, with respect to the axis B and the axis C,
The shaft center C is set to be inclined with respect to the shaft center B in both the side view and the plan view, the shaft center A is inclined rearward and downward with respect to the shaft center B in the side view, and the shaft center is seen in the plan view. The axis C is inclined with respect to B so as to shift to the outer side of the vehicle width toward the rear.

With respect to the trailing link 60, the trailing link 60 is formed in a curved shape so as to go inward toward the rear end side and is arranged in a substantially front-rear direction, and its front end portion 61 is provided with a ball joint. Rear lower pivot 15
The trailing link 60 has a connecting shaft portion 62 at the rear end thereof connected to the pivot bracket 5c at the rear portion of the suspension cross member 5 via a connecting portion 63 including a rubber bush having an axial center in a substantially front-rear direction. The connecting shaft portion 62 is connected to the pivotally mounted bracket 5c in a relative movement restraint state in the axial direction.

The stabilizer 70 is formed by integrally forming a pair of left and right arm portions 71 and a torsion bar portion 72 connecting the rear ends of the arm portions 71. The end portion of the arm portion 71 has a control link 73. It is connected to the upper end of the leg portion 27 on the front side of the fork member 26 through.
The kingpin axis K connecting the center of the upper pivot portion 13 and the center of the lower pivot portion 14 is set so that the kingpin offset has a small positive value as shown in FIG. 1, and also shown in FIG. Is set so that an appropriate caster angle and caster trail Ct can be obtained.

Next, the operation of the vehicle suspension device described above will be described. First, the kingpin axis K
5, the line L connecting the bush at the inner end of the I arm 50 and the mount portion that mounts the upper end of the shock absorber 20, the ball joint at the outer end of the I arm 50, and the outer end of the upper arm 40. Assuming that the point of intersection with the line M connecting the ball joint of is the point P and the instantaneous center of the I arm 50 and the trailing link 60 is the point Q, the line connecting the intersection P and the instantaneous center Q becomes the kingpin axis K, As described above, since the kingpin offset can be set to a small positive value (however, it may be set to a value of substantially zero), torque steer and kickback can be improved.

FIG. 5 is a mechanical diagram of the suspension device FS. When the front wheel 1 bumps, the front wheel 1
At the same time, the wheel support 10 moves upward, the I arm 50 swings upward with the inner end portion 52 thereof as the center of rotation, and the rod 23 of the shock absorber 20 retracts.
The suspension device FS is in the state shown by the dotted line. Here, since the lower end portion of the shock absorber main body 21 (the lower end portion 27a of the leg portion 27 of the fork member 26) is connected to the I arm 50 via the rubber bush of the axial center A oriented in the substantially front-rear direction, the shock absorber. The main body 21 does not rotate around its axis, and its supporting rigidity is maintained sufficiently high.

When the amount of lift of the wheel support 10 during bumping is H, the length of the I arm 50 is m, and the length from the inner end portion 52 of the I arm 50 to the first pivot portion 28 is n, the first
The amount of rise h of the pivot portion 28 is H × (n / m), so the amount of rise h of the inner end portion 42 of the upper arm 40 is smaller than the amount of rise H of the wheel support 10. As a result, the inclination angle of the upper arm 40 increases, and thus an appropriate camber change in which the camber angle of the wheel support 10 becomes a negative value is ensured. Similarly, when the front wheel 1 rebounds, the ground camber can be made substantially zero. As described above, in order to secure the bump and the camber change at the time of rebound, the rubber bush of the first pivot portion 28 needs to be set to an appropriate hardness that is not too hard. The axis B that pivotally attaches the I-arm 50 to the vehicle body affects the pitch center height and affects the anti-dive geometry. On the other hand, the shaft center of the shock absorber 20 influences the caster angle, and affects various alignments such as roll center height, pitch center height, and damper efficiency.

Next, regarding the trailing link 60,
If the trailing link 60 is not provided, the wheel support 1 is provided by the braking force that acts on the tire from the road surface during braking.
A moment acts on 0, but trailing link 60
As a result, the longitudinal movement of the lower end of the shock absorber body 21 is restricted, and the shock absorber 20 does not swing in the longitudinal direction, so that the caster angle, that is, the caster trail Ct is maintained substantially constant, and the caster rigidity is secured. Here, at the time of bumping or rebounding, the I-arm 50 has the axis B
The action of tilting the shaft center C with respect to the shaft center B will be described with reference to FIG. 6, but the shaft center Cp is the shaft center parallel to the shaft center B. The shaft center C is inclined rearward and downward by an angle γ in the vertical plane with respect to the shaft center Cp, and is inclined by an angle δ toward the rear in the horizontal plane toward the outside of the vehicle width.

As described above, the inclination angle of the upper arm 40 increases due to the rise of the shock absorber body 21 during bumping. At this time, the upper arm 40 moves in the direction of increasing the swing angle relative to the axis C. It will swing in the direction of arrow f in the figure. At this time, the outer end portion of the upper arm 40 slightly moves rearward (in the direction of arrow g) due to the action of the angle γ, so that the caster angle slightly increases, and the outer end portion of the upper arm 40 comes to the rear due to the action of the angle δ. Is suppressed, the increase of the caster angle is suppressed, and the camber angle is slightly increased. That is, by properly setting the angles γ and δ, it is possible to appropriately set the change characteristics of the caster angle and the camber angle at the time of bumping and rehounding, and it is possible to improve the degree of freedom of the caster control and the camber control. ..

The trailing link 60 may be extended forward instead of rearward from the shock absorber 20. Further, as shown in FIG. 7, the fork member 26A and the upper arm 40A may be formed, and the inner end portions of the pair of front and rear arm portions 41 of the upper arm 40 may be connected to the front and rear side portions near the upper end of the fork member 26A. Alternatively, the inner end portions of the pair of front and rear arm portions 41 of the upper arm 26A may be pivotally attached to the inner portions near the upper end of the fork member 26A in the same manner as described above. Alternatively, the trailing end of the trailing link 60A may be connected to the vehicle body via a rubber bush having a vertical axis. Further, instead of the I-arm 50 and the trailing link 60, an A-arm that integrates them may be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a suspension device according to an embodiment of the present invention when viewed from the rear.

FIG. 2 is a plan view of the suspension device.

FIG. 3 is a side view of the suspension device as viewed in the direction of arrow 3 in FIG.

FIG. 4 is a perspective view of a main part of the suspension.

FIG. 5 is an operation explanatory view of the suspension device.

FIG. 6 is an operation explanatory view of the suspension device.

FIG. 7 is a view corresponding to FIG. 4 of a suspension device according to a modification.

FIG. 8 is an operation explanatory view of the strut-improved suspension device according to the related art.

[Explanation of symbols]

 20 shock absorber 21 shock absorber main body 40, 40A upper arm 50 I arm (lower arm) 60, 60A trailing link B axis of bush at base end pivot part C axis of bush at upper end pivot part

Claims (3)

[Claims] 1. A suspension device comprising an upper arm, a lower arm and a shock absorber, wherein a lower end portion of the shock absorber is connected to the lower arm and the upper arm is pivotally attached to a shock absorber body. The bushing of the base end pivoting portion that pivots and the bushing of the upper pivoting portion that pivotally attaches the upper arm to the shock absorber body are configured so as to each have a shaft center approximately in the longitudinal direction of the vehicle body, and the bushing of the upper pivoting portion. A suspension device for a vehicle, wherein the shaft center of the vehicle is arranged so as to be inclined with respect to the shaft center of the bush of the base end pivotally connecting portion. 2. The axial center of the bush of the upper pivot portion is
The vehicle body suspension device according to claim 1, wherein the suspension device is arranged so as to be inclined with respect to the axis of the bush of the proximal end pivotal portion in a side view of the vehicle body. 3. The shaft center of the bush of the upper pivot portion,
The vehicle body suspension device according to claim 1, wherein the suspension device is arranged so as to be inclined with respect to the axial center of the bush of the proximal end pivotal portion in a plan view of the vehicle body.