JP2002225528A - Strut suspension - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the riding comfort by reducing a wasteful load generated by repulsion of a suspension to the ground contact point load of a wheel. SOLUTION: Suppose that a point at which a perpendicular L4 of a strut centerline axis L1 passing a center point of a strut mount 2a which is a supporting member of a strut 2 to a vehicle body 6 intersects an axis line L2 is a point P6. A center axis L3 of a coil spring intersects a point P6, as viewed from the vehicle side, or is so arranged to pass near the point P6 that a vector of the composite force of repulsion to the strut and the coil spring 3 exerts in approximately the opposite direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strut type suspension in which struts and coil springs are separately provided.

[0002]

2. Description of the Related Art Heretofore, for example, as a vehicle rear suspension, there has been known a so-called strut with a coil spring, which is provided so as to wind a coil spring around an outer periphery of the strut. The strut with the coil spring has a disadvantage that the upper end of the strut is easily protruded upward and inwardly of the vehicle in order to avoid interference with the wheels, and the capacity of the luggage compartment is reduced.

[0003] In order to secure the capacity of the luggage compartment, various types have conventionally been proposed in which struts and coil springs are separated and the coil springs are arranged under the floor (below the vehicle body).

For example, Japanese Patent Publication No. Sho 62-9043 discloses that
Connect the lower end of the strut to the wheel hub, extend the strut substantially vertically above the wheel center in a side view of the vehicle body, and connect the lower end of the coil spring to the wheel hub just behind the strut, and connect the coil spring to the vehicle body. A technique of extending substantially vertically upward in a side view is disclosed.

[0005]

By the way, the wheels have
The upward wheel contact point load is always applied. In particular, when the wheels bump, such as when traveling on rough roads or turning,
The load is increased. The upward wheel contact point load is mainly shared by the reaction force between the strut and the coil spring.

However, in the rear suspension disclosed in Japanese Patent Publication No. 62-9043, when a load acting on the wheel contact point acting upwardly acts on a vertical axis passing through the wheel center from the wheel contact point, it acts on the strut. The resultant reaction force and the resultant force of the reaction force acting on the coil spring do not match the vector of the wheel ground contact point load, and a useless load acts in the vehicle longitudinal direction.

In this case, the load acting in the vehicle longitudinal direction is applied as a preload to, for example, a trailing link extending in the vehicle longitudinal direction. by the way,
The front bush provided on the vehicle body fixed point side of the trailing link has such a characteristic that it is soft in a normal range with respect to an axial load and becomes hard when a large load is input. Therefore, due to the preload applied to the trailing link, the soft property of the normal area of the front bush shifts to the hard area, and as a result, the harshness (vibration) deteriorates,
Riding comfort is reduced.

Further, when the load at the wheel ground contact point is increased, the preload of the trailing link is increased, and the durability of the trailing link is reduced. In particular, in a four-wheel drive vehicle and a rear-wheel drive vehicle, since the rear axle shaft passes through the wheel center, the coil spring cannot be disposed close to the axis passing through the wheel center. Preload is applied to the trailing link.

This will be briefly described with reference to FIG. In this case, in order to simplify the description, the coil spring 3 is, as a representative of the prior art, vertically upward with the lower end being supported by the swing support member 4 at a position offset rearward from the wheel center Wc. Has been extended. Further, the strut 2 is attached to the vehicle body 6 via a strut mount as a support member at a position where the lower end is offset backward from the wheel center Wc, and the center point P1 of the strut mount is positioned on the vertical axis of the wheel center Wc. It is arranged. Further, the intersection of the coil spring central axis L3 and the perpendicular L4 of the central axis of the strut 2 passing through the central point P1 of the strut mount is defined as P2.

Here, when the wheel ground contact point load W acts on the wheel 1, a reaction force F2 from the vehicle body 6 via the coil spring 3 is applied to the wheel 1 substantially in the direction of the coil spring center axis L3 with the point P2 as a fulcrum, as shown in FIG. And the reaction force F via the strut 2
1 acts on the point P1 as a fulcrum in a direction perpendicular to the strut center axis L1. On the other hand, the reaction force F3 from the trailing link 7 and the wheel contact point load W are balanced.

As a result, since the reaction force F3 is applied to the trailing link 7 as a preload, there is a disadvantage that the harshness is deteriorated and the riding comfort is deteriorated.

In view of the above circumstances, the present invention can reduce the preload applied to the trailing link generated by the application of the load on the wheel contact point, and can improve the riding comfort as well as traveling on a bad road. It is an object of the present invention to provide a strut suspension that can significantly improve the strength and durability of a trailing link by greatly reducing the preload even when driving or turning.

[0013]

According to a first aspect of the present invention, a wheel supporting member for rotatably supporting a wheel includes a strut, a coil spring and a swing supporting member which are separately provided from the strut. A vertical line passing through a center point of a strut center axis passing through a center point of a strut mount serving as a support member of the strut for a vehicle body, and intersecting a vertical axis passing through a wheel grounding point in the strut type suspension mounted on the vehicle body so as to be able to swing vertically. On the other hand, the center axes of the coil springs are set so as to intersect or pass in the vicinity thereof when viewed from the side of the vehicle body. Further, the coil spring is mounted on a swing support member extending at least in the vehicle width direction.

In such a configuration, the vector of the resultant force of the strut reaction force and the coil spring reaction force substantially coincides with the vector of the wheel contact point load from the wheel, and the generation of a force in the vehicle longitudinal direction is suppressed. .

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show a first embodiment of the present invention. Here, FIG. 1 is a plan view of a strut type suspension, FIG. 2 is a front view thereof, and FIG. 3 is a side view thereof. Note that the same components as those in FIG. 7 will be described using the same reference numerals.

The strut type suspension according to the present embodiment is a dual link strut type suspension which is relatively frequently employed as a rear suspension of a four-wheel drive vehicle and a rear wheel drive vehicle, and is an axle housing which is an example of a wheel support member. An axle shaft (not shown) extending from the vehicle width direction is rotatably pivoted to the wheel 8, and a wheel (rear wheel) 1 is attached to a portion of the axle shaft protruding outward from the axle housing 8. Is fixed, whereby the wheel 1 is pivotally attached to the axle housing 8.

A front lateral link 4 and a rear lateral link 5 which are examples of a swing support member behind the axle shaft.
Are arranged substantially in parallel, and each of the lateral links is also 4, 5
The outer ends 4a, 5a of the axle housing 8 are pivotally attached to the axle housing 8 via a resilient bush (not shown) at a position offset from the wheel center Wc at a lower rear portion thereof. Further, the inner ends 4b and 5b of the lateral links 4 and 5 are pivotally connected via a vehicle body elastic bush (not shown).

As shown in FIG. 2, each of the lateral links 4 and 5 has an inner end 4b, 5b and an outer end 4a, 5a.
, And further, as shown in FIG. 1, the front lateral link 4 projects somewhat outward in the vehicle width direction from the rear lateral link 5.

On the other hand, a trailing end 7a of the trailing link 7, which is an example of a swing support member extending in the front-rear direction of the vehicle body, is swingably movable vertically in the front lower portion of the axle housing 8 via an elastic bush. Being pivoted. The trailing link 7 extends to the front of the vehicle body while being curved inward in the vehicle width direction, and has a front end 7b pivotally attached to the vehicle body 6 via an elastic bush. Here, these elastic bushes are soft in a normal range and hard when a large load is input.

Further, behind the wheel center Wc of the axle housing 8, a strut 2 extends upward between the lateral links 4, 5, and a lower portion of the strut 2 is rigidly connected to the axle housing 8, and The upper end is rigidly connected to the vehicle body 6 via the strut mount 2a.
As shown in FIGS. 2 and 3, the upper end of the strut 2
It is fixed in a posture inclined inside the vehicle body and forward of the vehicle body. Here, a perpendicular line L4 of a strut center axis L1 passing through a center point P1 of a strut mount 2a, which is a support member of the strut 2 to the vehicle body 6, intersects an axis L2 connecting the wheel ground point P3 of the wheel 1 and the wheel center Wc. The point is set to a point P6.

In the present embodiment, for convenience, the center point P1 of the strut mount 2a is set on the axis L2 when viewed from the side of the vehicle body.
Is the same position as point P6. Therefore, the wheel ground point P
3. Wheel center Wc, strut mount center point P
1 are tandemly arranged on the same straight line.

A flange 4c is formed in the middle of the front lateral link 4. The lower end of the coil spring 3 is connected to the flange 4c, and the upper end of the coil spring 3 is connected to the vehicle body 6. As shown in FIGS. 2 and 3, this coil spring 3 is
The front lateral link 4 extends in a substantially swinging direction, and the center axis L3 of the front lateral link 4 is set so as to intersect with the point P6 or pass in the vicinity thereof when viewed from the side of the vehicle body.

The coil spring 3 is preferably installed on the load side of the wheel contact point, that is, on the outer end side of the front lateral link 4 as much as possible because the reaction force acting on the coil spring 3 is small.

When the arrangement of the coil spring 3 is strictly considered in three dimensions, the center of the outer bush at the outer end 4a of the front lateral link 4, the center of the inner bush at the inner end 4b, and the vehicle body fixing point of the coil spring 3 are considered. P5
Are set so that the extension plane of the virtual plane formed by the intersection with the point P6 or the vicinity of the point P6.

Next, the operation of the present embodiment having the above configuration will be described. During traveling of the vehicle, an upward wheel contact point load W always acts on the wheels. In particular, when traveling on a rough road or turning, the wheel 1 bumps and the load W on the ground contact point of the wheel increases, so that the axle housing 8 moves up and down, and the lateral links 4 pivotally mounted on the axle housing 8 respectively. , 5, and the trailing link 7 swing up and down around the inner ends 4b, 5b and the front end 7b.

At the same time, the coil spring 3 interposed between the front lateral link 4 and the vehicle body 6 and the strut 2 interposed between the axle housing 8 and the vehicle body 6 move up and down the axle housing 8. Compression and decompression operations are linked to movement.

At this time, in FIG. 3, the wheel contact point load W is defined by an intersection P4 between the center axis of the trailing link and the axis L2 on the axis L2 connecting the wheel contact point P3 of the wheel 1 and the wheel center Wc. Act on.

On the other hand, as the reaction force from the vehicle body 6, a strut reaction force F1 in the direction of the perpendicular L4 of the strut center axis L1 around the point P1 and a coil spring center axis L3 around the point P6 or in the vicinity thereof. Coil spring reaction force F
2 works.

As a result, the resultant vector of the strut half force F1 and the coil spring half force F2 is balanced in a direction substantially opposite to the vector of the wheel ground contact point load W, so that a useless load almost acts in the vehicle longitudinal direction. However, since the preload is hardly applied to the trailing link 7, the harshness is reduced, the riding comfort is improved, and the strength and durability of the trailing link are relatively improved.

As described above, according to the present embodiment, the center axis L3 of the coil spring 3 is set so as to intersect with the point P6 or pass in the vicinity of the point P6 when viewed from the side of the vehicle body. The resultant force vector of the reaction force F1, F2 of the strut 2 and the coil spring 3 with respect to the point load W acts in a direction substantially opposite to the vector of the wheel ground contact point load W, so that a preload is applied to the trailing link 7. The load is hardly applied, the harshness is reduced, and not only the riding comfort is improved, but also the strength and durability of the trailing link can be relatively improved.

FIGS. 4 and 5 show a second embodiment of the present invention. In the first embodiment, the mode in which the coil spring 3 is interposed between the front lateral link 4 and the vehicle body 6 has been described. In the present embodiment, the coil spring 3 is provided in the lower arm 9 of the inverted A-arm type strut suspension. It is interposed between the vehicle body 6 and other components are the same as those in the first embodiment.

That is, the front lateral link 4 and the rear lateral link 5 are disposed substantially in parallel, and the coil spring 3
Instead of being provided in the middle of the front lateral link 4, one lower arm 9 extending in the vehicle width direction is provided, and the lower end of the coil spring 3 is connected to the flange 9 c formed in the middle of the lower arm 9, and the upper end is provided. Connected to vehicle body 6.

As in the first embodiment, it is preferable to install the coil spring 3 on the load side of the wheel contact point as much as possible, that is, on the outer end side of the lower arm 9 because the reaction force acting on the coil spring 3 is small. .

In this case, as shown in FIG. 5, the coil spring 3 extends substantially in the swinging direction of the lower arm 9 when viewed from the front of the vehicle body, and its center axis L3 intersects the point P6 when viewed from the side of the vehicle body. Or, it is set so as to pass through the vicinity thereof.

That is, when the arrangement of the coil spring 3 is strictly considered in three dimensions, the extension plane of the virtual plane formed by the center of the inner bush at the inner end 9b of the lower arm 9 and the center axis L3 of the coil spring 3 is point P6. Crosses with
Alternatively, it is set so as to pass near the point P6.

As a result, when the wheel ground contact point load W acts on the wheel 1, as in the first embodiment, the strut reaction force F1
And the coil spring reaction force F2 are balanced in a direction substantially opposite to the vector of the wheel ground contact point load W, so that a useless load hardly acts in the front-rear direction of the vehicle body and almost no preload is applied to the trailing link 7. Since no load is applied, harshness is reduced, riding comfort is improved, and the strength of the trailing link,
The durability is improved.

The present invention is not limited to each of the above-described embodiments. For example, the suspension structure is not limited to the dual link type, but may be a multi-link type.
Further, the front lateral link may be disposed forward of the wheel center.

In the present embodiment, for convenience, the center point P1 of the strut mount 2a, which is a support member for the strut 2 to the vehicle body 6, is defined by the wheel ground point P3 of the wheel 1 and the wheel center Wc in a side view of the vehicle body. Are set at the same position as the point P6 on the axis L2 connecting the two, and for example, as shown in FIG. 6, the center point P1 of the strut mount 2a is
It is not necessary to be on the axis L2, and the position of the strut 2 and the center point P1 of the strut mount 2a are not limited to the present embodiment. That is, in this case, a point at which a perpendicular L4 of the strut center axis L1 passing through the center point P1 of the strut mount 2a intersects with the axis L2 is defined as a point P6.
The arrangement of the coil spring 3 may be satisfied so as to intersect with the path 6 or pass near the point P6 as in the arrangement conditions of the coil springs in the first and second embodiments.

[0039]

As described above, according to the present invention,
The coil spring arrangement is set so that the resultant vector of the strut reaction force and the coil spring reaction force acts in almost the opposite direction with respect to the wheel contact point load vector. Not only can the preload applied to the trailing link be reduced, and the riding comfort can be improved. The strength and durability of the ring link can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a strut type suspension according to a first embodiment.

FIG. 2 is a front view of the strut suspension.

FIG. 3 is a side view of the strut type suspension.

FIG. 4 is a plan view of a strut type suspension according to a second embodiment.

FIG. 5 is a side view of the strut suspension.

FIG. 6 is a side view of a strut type suspension according to another embodiment.

FIG. 7 is a side view of a conventional strut type suspension.

[Description of Signs] 1 wheel 2 strut 3 coil spring 6 body 7 trailing link (oscillating member) 8 axle housing (wheel supporting member) 9 lower arm L1, L3 center axis L2 axis L4 perpendicular P3 wheel grounding point W grounding point load Wc Wheel Center

Claims (2)

[Claims] 1. A strut suspension in which a wheel supporting member for rotatably supporting a wheel is vertically swayably attached to a vehicle body via a strut, a coil spring and a swing supporting member separately provided from the strut. The central axis of the coil spring intersects the point where the perpendicular of the central axis of the strut passing through the central point of the strut mount, which is a support member of the strut to the vehicle body, intersects with the vertical axis passing through the wheel ground point, as viewed from the side of the vehicle body. Or a strut type suspension set so as to pass through the vicinity thereof. 2. A strut type suspension according to claim 1, wherein said coil spring is mounted on a swing support member extending at least in a vehicle width direction.