JP2767961B2 - Vehicle suspension - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a suspension of a vehicle such as an automobile,
More specifically, the present invention relates to a suspension member type suspension.

[Prior Art] As one of suspensions of vehicles such as automobiles, for example, the “Toyota Mark II New Instruction Manual” issued on August 24, 1988 by the service department of the present applicant, Toyota Motor Corporation. As described on page 2-50, a carrier rotatably supporting a wheel, and a suspension suspended and supported by a vehicle body through a plurality of bush devices spaced apart from each other with directionality in spring constant. A member, a control arm pivotally supported by the suspension member at the inner end and pivotally attached to the carrier at the outer end, and a shock absorber and spring etc. pivotally supported by the vehicle body at the upper end and pivotally attached to the carrier at the lower end. A suspension member type suspension including a vertical force transmitting member is already known.

[Problems to be Solved by the Invention] However, in the conventional suspension member type suspension described in the above-mentioned manual, the axis of the bush device extends in the vertical direction, without impairing the riding comfort of the vehicle. In order to increase the lateral rigidity of the vehicle, the spring constant of the bush device is set high in the lateral direction of the vehicle but low in the front-rear direction and the vertical direction of the vehicle. Therefore, when the vehicle turns or accelerates or decelerates, the suspension member is likely to undergo roll displacement or pitch displacement, and it is difficult to ensure good steering stability of the vehicle.

The present invention has been made in view of the above-described problems in the conventional suspension member type suspension as described above, and the suspension member does not substantially generate a roll displacement or a pitch displacement even during turning or acceleration / deceleration of the vehicle. It is an object of the present invention to provide a suspension member type suspension improved so that good steering stability can be secured without impairing the ride comfort of the vehicle.

According to the present invention, a carrier for rotatably supporting a wheel and a spring constant at at least two positions separated from each other in a vehicle width direction are provided. A suspension member suspended and supported by the vehicle body via a bush device having a characteristic, a control arm pivotally supported by the suspension member at an inner end and pivotally attached to the carrier at an outer end, and A vertical force transmitting member pivotally attached to the carrier at the lower end thereof, and an intersection point between the axis of the vertical force transmitting member and the road surface when the vehicle in a standard state is viewed in the front-rear direction is defined as P. Assuming that an intersection point between a straight line Lr connecting the carrier and the instantaneous center O of the carrier and a vertical center line of the suspension member is Cr, the direction of the high spring constant of the bush device is the same as the intersection of A vehicle suspension substantially aligned with a straight line connecting Cr and a carrier rotatably supporting wheels; and a spring constant having directionality in at least two positions spaced apart from each other in the longitudinal direction of the vehicle. A suspension member suspended from the vehicle body via a bush device; a control arm pivotally supported by the suspension member at an inner end and pivotally mounted to the carrier at an outer end; and a control arm pivotally supported by the vehicle body at an upper end. An upper and lower force transmitting member pivotally attached to the carrier at a lower end thereof, wherein an intersection between the axis of the vertical force transmitting member and the road surface is P when the vehicle in a standard state is viewed laterally;
Assuming that a straight line connecting L and the instantaneous center O of the carrier is Lp, the two bush devices are arranged such that an intersection Cp of a straight line passing through the center thereof and along the direction of the high spring constant is located on the straight line Lp. Achieved by vehicle suspension.

According to the former configuration described above, when the vehicle in the standard state is viewed in the front-rear direction, the intersection between the axis of the vertical force transmitting member and the road surface is determined by P.
The intersection of the straight line Lr connecting the intersection point P and the instantaneous center O of the carrier with the vertical center line of the suspension member is Cr, and the direction of the high spring constant of the bush device is a straight line connecting the center and the intersection point Cr. Because they are virtually aligned,
The intersection Cr is substantially the instantaneous center of the roll motion of the suspension member with respect to the vehicle body.

In this specification, the "standard state" means a state in which the vehicle is stationary and the wheels are in a neutral position of the bounding and rebound displacement.

Therefore, when the lateral force Fl acts on the wheels from the road surface, this lateral force is transmitted to the vehicle body via the vertical force transmitting member and also to the suspension member via the control arm, so that the lateral force is applied to the axis of the control arm. And the component Flh along the straight line Lr can be considered.The component Flh along the straight line Lr is a force acting on the intersection point Cr. Swing in the roll direction is avoided, so that even when the vehicle turns, the suspension member does not substantially cause roll displacement, and good steering stability is secured without impairing the riding comfort of the vehicle. .

Further, according to the latter configuration, when the vehicle in the standard state is viewed laterally, the intersection between the axis of the vertical force transmitting member and the road surface is P, and the straight line connecting the intersection P and the instantaneous center O of the carrier is defined as
As Lp, the two bush devices are arranged such that the intersection Cp of a straight line passing through the center thereof and along the direction of the high spring constant is located on the straight line Lp, and the intersection Cp is substantially the pitch movement of the suspension member with respect to the vehicle body. Is the moment's center.

Therefore, when the longitudinal force Fa acts on the wheels from the road surface, this lateral force is transmitted to the vehicle body via the vertical force transmitting member,
Since the longitudinal force Fa is transmitted to the suspension member via the control arm, the longitudinal force Fa can be decomposed into a component Fav along the axis of the vertical force transmitting member and a component Fah along the straight line Lp, and the component Fah along the straight line Lp can be considered. Is a force acting on the intersection Ppl, and this force prevents the suspension member from swinging in the pitch direction relative to the vehicle body,
Thereby, even when the vehicle is accelerated or decelerated, the suspension member does not substantially generate a pitch displacement, and good steering stability is secured without impairing the riding comfort of the vehicle.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[Embodiment] FIG. 1 is a rear view showing a first embodiment of a suspension according to the present invention in a standard state as a skeleton diagram projected on a virtual vertical plane from the rear of a vehicle, and FIG. 2 is shown in FIG. It is explanatory drawing which shows operation | movement of the Example.

In FIG. 1, 10R and 10L are wheels 12R and 12L, respectively.
Shows a carrier that rotatably supports, and 14 shows a suspension member. The outer ends of an upper control arm 16R and a lower control arm 18R are pivotally connected to the upper and lower ends of the carrier 10R by joints, respectively, and these control arms are pivotally supported by the suspension members 14 at the inner ends by the joints. . A lower end of a shock absorber 20R is pivotally connected to the carrier 10R by a joint, and an upper end of the shock absorber is pivotally supported on the vehicle body 22 by an upper support. A spring 24R is mounted between the vehicle body and the carrier along the shock absorber, and cooperates with the shock absorber to define a vertical force transmitting member 26R.

Similarly, the outer ends of an upper control arm 16L and a lower control arm 18L are pivotally connected to the upper and lower ends of the carrier 10L by joints, respectively. Have been. Also career
The lower end of the shock absorber 20L is pivotally connected to the 10L by a joint, and the upper end of the shock absorber is pivotally supported on the vehicle body 22 by an upper support. Spring 24 between the body and carrier along the shock absorber
L is mounted and cooperates with a shock absorber to define a vertical force transmitting member 26L.

As is well known, the instantaneous center of the carrier 10R is the intersection Orr of the straight lines 28R and 30R connecting the centers of the joints at both ends of the upper control arm 16R and the lower control arm 18R, and similarly, the instantaneous center of the carrier 10L is the upper control arm 16L and The intersection Orl of the straight lines 28L and 30L connecting the centers of the joints at both ends of the lower control arm 18L. Axis lines 32R and 32L of vertical force transmitting members 26R and 26L and road surface
Assuming that the intersections with 34 are Pr and Pl, respectively, and the straight lines connecting these intersections and the instantaneous centers Orr and Orl of the corresponding carriers are Lrr and Lrl, respectively, these straight lines are the vertical center lines 36 of the vehicle body and the suspension member. They cross each other at the upper point Crr.

The suspension member 14 includes four bushing devices 38FR, 38FL, 38RR, and 38 that are spaced apart from each other in the front-rear and left-right directions of the vehicle.
FIG. 1 shows only the bush devices 38RR and 38RL on the rear side of the vehicle. Each of the bush devices has a directional spring constant. The spring constant in a predetermined direction perpendicular to the axis is set high, and the spring constants in other directions are set low, as described later.

FIGS. 3 and 4 are cross-sectional views, perpendicular to the axis, of one embodiment of a bushing device that may be incorporated into the suspension shown in FIG. In these figures, parts corresponding to each other are denoted by the same reference numerals.

In the bush device shown in FIG. 3, the rubber bush 44 disposed between the inner cylinder 40 and the outer cylinder 42, which are concentric with each other, is commonly referred to as a position spaced apart from each other in the radial direction. A pair of cavities 46 and 48 called "boring" are provided, so that the spring constant in the vertical direction as shown in FIG. 3 is set high and the spring constant in the other directions is set low.

In the bush device shown in FIG. 4, the rubber bush 44 is disposed around the entire circumference between the inner cylinder 40 and the outer cylinder 42 which are concentric with each other, and is spaced apart from each other in the radial direction. A pair of arc-shaped metal plates 50 and 52 commonly called "intering" are buried in the position where
In the figure, the spring constant in the vertical direction is set high, and the spring constant in the other directions is set low.

In the embodiment shown in FIG. 1, each bushing device is arranged so that its axis extends substantially in the longitudinal direction of the vehicle, and a shaft inserted through the inner cylinder is fixed to the vehicle body. The outer cylinder is fixed to the suspension member, thereby elastically connecting the vehicle body and the suspension member. In FIG. 1, the directions in which the spring constants of the bush devices 38RR and 38RL are high are indicated by straight lines Hrr and Hrl, respectively, which pass through the intersection Crr. Therefore, the intersection Crr is substantially the instantaneous center of the roll motion of the suspension member with respect to the vehicle body. The intersection Crr is located near the roll center Cm of the suspension member, which is determined as the intersection of a straight line connecting the instantaneous centers Orr and Orl and the ground contact point of the corresponding wheel and the vertical center line 36, and particularly the intersections Pr and Pl When the ground point of the wheel is coincident, the intersection Crr and the roll center Cm are the same point.

Although not shown in FIG. 1, the bush devices 38FR and 38FL are incorporated similarly to the bush devices 38RR and 38RL, respectively.

As shown in FIG. 2, the wheels 12R and 1
Assuming that the lateral force Fl acts on 2L, this lateral force is transmitted to the vehicle body via the vertical force transmitting member and to the suspension member via the upper and lower control arms. Component Fl along 32R, 32L
v and a component Flh along the straight lines Lrr and Lrl. Since the component Flh along the straight lines Lrr and Lrl is a force acting on the intersection Crr, the suspension member does not swing relative to the vehicle body in the roll direction due to these forces, and the intersection Crr is at the roll center Cm. , The suspension member is not substantially swung in the roll direction with respect to the road surface.

FIG. 5 is a side view showing a second embodiment of the suspension according to the present invention in a standard state as a skeleton diagram projected on a virtual vertical plane from the outboard side of the vehicle, and FIG. 6 is an embodiment shown in FIG. It is explanatory drawing which shows operation | movement of an example. In these figures, parts corresponding to the parts shown in FIGS. 1 and 2 are denoted by the same reference numerals as those shown in FIGS. 1 and 2.

Also in this embodiment, the suspension member 14 is composed of four bush devices spaced apart from each other in the front-rear and left-right directions of the vehicle.
It is suspended from the vehicle body 22 via 38FR, 38FL, 38RR, 38RL, but in Fig. 5, the bush device on the left side of the vehicle is shown.
Only 38FL and 38RL are shown. Each bushing device is arranged so that its axis extends substantially in the lateral direction of the vehicle. In FIG. 5, directions in which the spring constants of the bush devices 38FL and 38RL are high are indicated by straight lines Hfl and Hrl, respectively, and these straight lines intersect with each other at an intersection Cpl. Therefore, the intersection point Cpl is substantially the instantaneous center of the pitch movement of the suspension member with respect to the vehicle body.

As is well known, the instantaneous center of the carrier 10L is the intersection Opl of the straight lines 56L and 58L connecting the centers of the joints at the inner ends of the upper control arm 16L and the lower control arm 18L, and the straight line connecting the intersection Pl and the instantaneous center Opl is represented by Lpl. Then, the intersection Cpl is located on the straight line Lpl.

As shown in FIG. 6, assuming that a longitudinal force Fa acts on the wheel 12L from the road surface 34, this lateral force is transmitted to the vehicle body via the vertical force transmitting member, and is also transmitted via the upper and lower control arms. Is transmitted to the suspension member, and the longitudinal force Fa is applied to the component Fav along the axis 32L and the straight line.
It can be considered by decomposing it into a component Fah along Lpl. Since the component Fah along the straight line Lpl is a force acting on the intersection Cpl, the suspension member does not swing relative to the vehicle body in the pitch direction due to this force, and the intersection Cp
Since l is located near or at the same position as the ground contact point of the wheel, the suspension member is not substantially swung in the pitch direction with respect to the road surface.

The spring constant of each bush device in the front-rear direction is low,
Because the Cpl is located far enough below the axis of rotation of the wheel, each bushing device is well elastically deformed even if force is applied to the axis of rotation of the wheel, such as harshness, and sufficient compliance is achieved. , The ride comfort of the vehicle is not degraded.

FIGS. 7 and 8 show the third embodiment of the suspension according to the invention in the standard state as skeleton diagrams projected on a virtual vertical plane from the rear side and outboard side of the vehicle, respectively. 9 and FIG. 9 are explanatory views of the operation of the embodiment shown in FIGS. 7 and 8 as viewed from above the vehicle. In these figures, parts corresponding to the parts shown in FIGS. 1 and 5 are denoted by the same reference numerals as those shown in FIGS. 1 and 5.

Also in this embodiment, the suspension member 14 is composed of four bush devices spaced apart from each other in the front-rear and left-right directions of the vehicle.
The bush device is suspended from the vehicle body 22 via the 38FR, 38FL, 38RR, and 38RL. As shown in FIG. 9, each bush device has its axis inclined with respect to the lateral and longitudinal directions of the vehicle. It is arranged to extend. In FIG. 9, the directions in which the spring constants of the bush devices 38FR, 38FL, 38RR, and 38RL are high are indicated by straight lines Hfr, Hfl, Hrr, and Hrl, respectively.

The straight lines Hfr and Hfl intersect each other at the intersection Crf, and the straight line Hrr
And Hrl cross each other at the intersection Crr. The intersection Crf and the intersection Crr are located at the same position as the intersection Crr in FIG. 1 when viewed in the longitudinal direction of the vehicle, that is, substantially at the instantaneous center of the roll motion of the suspension member with respect to the vehicle body. Also a straight line
Hfl and Hrl cross each other at the intersection Ppl, and straight lines Hfr and Hr
r intersect each other at the intersection Ppr. Intersection point Ppl and intersection point P
pr is located at the same position as the intersection Ppl in FIG. 5 when viewed in the lateral direction of the vehicle, that is, substantially at the instantaneous center of the pitch movement of the suspension member with respect to the vehicle body, and is spaced sufficiently below the rotation axis of the wheel. I have.

Therefore, in this embodiment, the same operation and effects as those of the first and second embodiments are obtained, and the lateral force acting on the wheels from the road surface causes the suspension member to move relative to the vehicle body. The suspension member does not swing in the pitch direction relative to the vehicle body due to the component of the longitudinal force acting on the wheels from the road surface acting on the suspension member. Does not deteriorate the ride comfort of the vehicle.

Although the present invention has been described in detail with reference to some embodiments, the present invention is not limited to these embodiments, and various other embodiments are possible within the scope of the present invention. Will be apparent to those skilled in the art.

For example, in the above-described embodiment, the vertical force transmitting member is directly pivoted to the carrier at the lower end. May be pivotally attached to the carrier. Further, the upper control arm or the lower control arm may be replaced with a radius rod.

[Effects of the Invention] As is clear from the above description, according to the present invention,
In the former configuration described above, even if the lateral force Fl acts on the wheels from the road surface, the suspension member can be prevented from swinging in the roll direction relative to the vehicle body. In the latter configuration, the front-rear force Fa
Can prevent the suspension member from swinging in the pitch direction relative to the vehicle body, so that the suspension member generates roll displacement or pitch displacement during turning or acceleration / deceleration of the vehicle. To prevent
Good steering stability can be ensured without impairing the riding comfort of the vehicle.

[Brief description of the drawings]

FIG. 1 is a rear view showing a first embodiment of a suspension according to the present invention in a standard state as a skeleton diagram projected on a virtual vertical plane from the rear of a vehicle, and FIG. 2 is a view of the embodiment shown in FIG. FIG. 3 is an explanatory view showing the operation, FIG. 3 and FIG. 4 are sectional views taken along a line perpendicular to an axis showing one embodiment of a bush device which may be incorporated into the suspension shown in FIG. 1, and FIG. 5 is a side view showing a second embodiment of the suspension according to the present invention as a skeleton diagram projected on a virtual vertical plane from the outboard side of the vehicle, and FIG. 6 is an explanation showing the operation of the embodiment shown in FIG. FIGS. 7, 7 and 8 show skeleton diagrams of a third embodiment of the suspension according to the invention in a standard state, respectively, projected on a virtual vertical plane from the rear and outboard sides of the vehicle. And a rear view and a side view corresponding to FIG. 5, FIG. 9 is an explanatory view as seen from above the vehicle showing the operation of the embodiment shown in FIGS. 7 and 8. 10R, 10L …… Carrier, 12R, 12L …… Wheels, 14 …… Suspension member, 16R, 16L …… Upper control arm, 18R, 18L …… Lower control arm, 20R, 20L ……
Shock absorber, 22 …… Car body, 24R, 24L …… Spring, 26R, 26L …… Vertical force transmission member, 38FR, 38FL, 38RR, 38
RL bushing device, 40 inner cylinder, 42 outer cylinder, 44 rubber bush, 46, 48 hollow part, 50, 52 metal plate, 54
…bracket

Claims (2)

(57) [Claims] 1. A carrier for rotatably supporting wheels, a suspension member suspended from a vehicle body via at least two bush devices spaced apart from each other in a vehicle width direction and having a directional spring constant, and an inner end. A control arm pivotally supported by the suspension member and pivotally attached to the carrier at an outer end, and a vertical force transmitting member pivotally supported by the vehicle body at an upper end and pivotally attached to the carrier at a lower end. When the vehicle in the standard state is viewed in the front-rear direction, the intersection point between the axis of the vertical force transmitting member and the road surface is P, the straight line Lr connecting the intersection point P and the instantaneous center O of the carrier and the vertical center of the suspension member. Assuming that the point of intersection with the line is Cr,
The bush device is a vehicle suspension in which the direction of the high spring constant is substantially aligned with a straight line connecting the center and the intersection point Cr. 2. A carrier for rotatably supporting wheels, a suspension member suspended from the vehicle body via at least two bush devices spaced apart from each other in the front-rear direction of the vehicle and having directionality in a spring constant. A control arm pivotally supported by the suspension member at one end and pivotally attached to the carrier at an outer end; and a vertical force transmitting member pivotally supported by the vehicle body at an upper end and pivotally attached to the carrier at a lower end. When the vehicle in the standard state is viewed in the lateral direction, the intersection between the axis of the vertical force transmitting member and the road surface is P, and the intersection P
Assuming that a straight line connecting L and the instantaneous center O of the carrier is Lp, the two bush devices are arranged such that an intersection Cp of a straight line passing through the center thereof and along the direction of the high spring constant is located on the straight line Lp. Vehicle suspension.