JPH10181321A - Front suspension device - Google Patents

Abstract

(57) [Summary] A double wishbone type front suspension device for supporting a wheel supporting member above a tire,
Improves ride comfort and turning stability. The two upper links arranged above the tire are twisted with respect to each other, and a virtual intersection R defined by the midpoint of the shortest distance between the two links and a lower A arm, for example.
A virtual kingpin axis K is set by connecting the virtual kingpin axis lower point S formed by the wheel supporting member side connection point of the wheel support member 1, and the lower end input point O of the shock absorber 12 is set on the virtual kingpin axis K on the wheel supporting member 1. , The ride ratio is set to "1" to improve ride comfort. Also, the connection points E and F on the wheel support member side of the two upper links 7 and 8 are both arranged in front of the vehicle on the vehicle body member side connection points J and I, and the camber is corrected in the negative direction during turning to stabilize turning. Improve the performance. The coil spring 16 is provided separately from the shock absorber 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle front suspension device.

[0002]

2. Description of the Related Art Conventional front suspension devices are described in, for example, Japanese Utility Model Laid-Open No. 52-106919 (hereinafter also referred to as Conventional Example 1) and Japanese Patent Laid-Open No. 63-232010 (hereinafter also referred to as Conventional Example 2). There are things to be done.

In each of the front suspension devices described in the prior art examples 1 and 2, the upper end of a wheel supporting member located above the tire is connected to a vehicle body member so as to be swingable by an upper link or an arm member. The lower end is swingably connected to the vehicle body member by a lower link or an arm member, and the lower end input point of the shock absorber is connected to an intermediate portion of the lower link or the arm member. In addition,
Each of the front suspension devices described in the conventional examples 1 and 2 has a so-called upper link high mount type double wishbone type suspension structure in which an upper link or an arm member is disposed above a tire. Example 1 uses an A-type arm member type arm member for both the upper and lower parts, and Conventional Example 2 uses two link members for both the upper and lower parts. Therefore, the virtual kingpin axis of Conventional Example 1 is a straight line connecting the connection points on the wheel support member side of the upper and lower A-shaped arm members, and the virtual kingpin axis of Conventional Example 2 is the straight line connecting the upper and lower two link members. It is a straight line connecting the virtual intersections.

[0004]

However, the above-mentioned conventional steering wheel suspension apparatus has the following problems.

That is, the front suspension according to the conventional example 1 or 2 is used.
When the pension device is represented in a skeletal diagram when viewed from the front of the vehicle
FIG. 10A (virtual kingpin axis of Conventional Example 2)
Is connected to the upper and lower arms or link members on the wheel support member side
Replace it with a straight line connecting the points). Also, in FIG.
Place the coil spring coaxially with the shock absorber
Are shown. With these front suspension devices
Is the lower link of the shock absorber at the lower link or
Because it is connected to the arm member, the suspension
The damping force of the shock absorber during stroke is
The torque is not generated around the virtual kingpin axis.
There is a point. This is when the shock absorber stroke
Because it is hard to cause a transient toe change,
It can be said that it is excellent in maneuverability such as straightness on uneven roads. However
On the other hand, the shock absolute
Lever ratio (k <
1). Therefore, for example, as shown in FIG.
Up or down at the connection point of the link
Force F₁When the shock acts, the shock absorber
Vertical force F_TwoHowever, the difference between the two
Vertical force F corresponding to reaction force _Three(= F₁-F_Two) Is entered
You. Therefore, especially on rough roads where there are many transient vertical inputs.
Vertical force F_ThreeIs directly input to the body members and the ride quality is reduced.
There is a problem of doing.

The present invention has been developed in view of these problems. In a high-upper link type double wishbone suspension structure, two upper link members are set at a twisted position, and a virtual intersection thereof is formed. The input point at the lower end of the shock absorber is arranged on a virtual kingpin axis connecting the link and the (virtual) connection point between the lower link or the arm member and the vehicle body support member, so that the shock absorber can be provided without providing a separate kingpin or kingpin bearing. An object of the present invention is to provide a front suspension device capable of improving ride comfort by setting a lever ratio to “1”.

[0007]

According to a first aspect of the present invention, there is provided a front suspension device comprising: a wheel support member located above a tire; The front suspension device is swingably connected to the vehicle body member via the upper link member, and the lower end of the wheel support member is swingably connected to the vehicle body member via the lower A-shaped arm member and the tie rod member. The two upper link members are twisted, and the lower end input point of the shock absorber is arranged on a straight line connecting the virtual intersection and the connection point on the wheel support member side of the lower A-arm member. It is assumed that.

[0008] There is no intersection between the two upper link members at the twist position. However, since the midpoint of the shortest distance line between the two upper link members functions as the upper point forming the virtual kingpin axis, this point is defined as the virtual intersection of the twisted link members.
Therefore, the virtual intersection of the two upper link members and the lower A
The straight line connecting the die arm member to the wheel support member side connection point is the virtual kingpin axis of this upper link high mount type double wishbone suspension structure. Also, since the lower input point of the shock absorber must be arranged on this virtual kingpin axis, the lower input point of the shock absorber is substantially
It is directly connected to the wheel support member without any other link or arm member. Further, the structure in which the lower end input point of the shock absorber is directly connected to the wheel support member on the virtual kingpin axis in this manner is such that the connection point of the upper link or the arm member on the wheel support member side is located above the inside of the tire. It cannot be configured with a so-called upper link low mount type double wishbone suspension. Further, in a state where the lower end input point of the shock absorber is connected to the wheel support member, if the virtual intersection is to be constituted by a wheel support member side connection point of the upper A-type arm member, for example,
In effect, the distance between the connection point on the wheel support member side and the connection point on the vehicle body member side becomes too short, that is, the length of the upper A-type arm member itself becomes too short, and the ground camber characteristic at the time of wheel stroke. The well-known problem that the image quality deteriorates. Therefore, in order to obtain a sufficient length of the upper link member and secure the ground camber characteristic while securing the upper point constituting the kingpin axis, it is necessary to arrange the two upper link members at the twisted positions. Required.

According to a second aspect of the present invention, in the front suspension device, a coil spring is disposed on the lower A-shaped arm member. This is a problem avoidance measure when the coil spring is arranged coaxially with the shock absorber. When the coil spring is arranged coaxially with the shock absorber, in order to avoid interference between the coil spring and the wheel (tire), the upper vehicle body side connection point of the shock absorber must be moved further inward in the vehicle width direction. Specifically, in the case of a front suspension device, the layout of an engine or the like is hindered, and disadvantages occur. Therefore, by disposing the coil spring on the lower A-shaped arm member separately from the shock absorber, layout disadvantages are avoided.

Further, the front suspension device according to claim 3 of the present invention is characterized in that an axis of the shock absorber passes through a wheel contact point when the vehicle body is viewed from the side.

Further, in the front suspension device according to a fourth aspect of the present invention, any one of the connection points of the two upper link members on the wheel support member side is located forward of the vehicle body member from the connection point on the vehicle body member side in a plan view of the vehicle. It is characterized by being arranged.

In the front suspension device according to a fifth aspect of the present invention, the distances between the connection points of the two upper link members on the wheel support member side and the virtual intersection are set to be equal or substantially equal. It is characterized by having done.

According to a sixth aspect of the present invention, in the front suspension device, the upper link member of the two upper link members, the connection point of which is connected to the wheel support member, is located at the front of the vehicle. Is arranged above the upper link member at the rear of the vehicle.

In a general vehicle front suspension device, since the caster is provided on the virtual kingpin axis described above, the virtual intersection of the two upper link members constituting the virtual kingpin axis upper point above the tire is the wheel center point. It is located slightly behind the vehicle. Therefore, of the two upper link members, the connection point with the wheel support member on the wheel support member side of the upper link member whose connection point with the wheel support member is in front of the vehicle is at least along the outer circumferential arc of the rear half of the tire. The connection point with the member must be above the connection point on the wheel support member side of the upper link member at the rear of the vehicle. Therefore,
By disposing the former upper link member above that of the latter, the two wheel support member side connection points are arranged outside the outer circumferential arc of the rear half of the tire.

According to a seventh aspect of the present invention, there is provided the front suspension device, wherein, of the two upper link members, a connection point with the wheel support member is connected to an upper link member located in front of the vehicle. The rigidity of the bush used at the point in the axial direction of the link member is set lower than that of the bush used at the connection point of the other upper link member.

At the time of braking, both the connection points of the upper link member on the wheel support member side receive a forward force due to the braking torque around the axle. At this time, the upper link member having the wheel support member-side connection point at the rear of the vehicle moves the wheel support member-side connection point inward in the vehicle width direction with the rotation of the link member about the vehicle body member-side connection point. Be drawn in. Therefore,
By lowering the rigidity in the axial direction of the link member of the bush used for the upper link member at the wheel support member side connection point in front of the vehicle, the entire upper link member moves outward in the vehicle width direction. Thus, the wheels during braking are relatively used as toe-outs, and the stability particularly during turning braking is improved.

In the front suspension device according to claim 8 of the present invention, the wheel supporting member is swingably attached to the vehicle body member using two lower link members instead of the lower A-shaped arm member. And connecting the lower end input point of the shock absorber on a straight line connecting the intersection point of the two lower link members and the virtual intersection point.

[0018]

As described above, according to the front suspension device of the first aspect of the present invention, the virtual intersection point of the two upper link members and the connection point of the lower A-shaped arm member on the wheel support member side. By connecting the lower end input point of the shock absorber to the wheel support member and arranging it on the straight line that connects the shock absorber, the lever ratio of the shock absorber is set to "1" to ensure ride comfort, and individual kingpins, kingpin bearings and third Only sentences that do not require a link member are advantageous in terms of layout, weight, and cost. Of course, by forming the virtual intersection with the two upper link members as twist positions, a sufficient length of each upper link member can be obtained. Therefore, the ground camber characteristics at the time of the wheel stroke can be secured.

Further, according to the front suspension device of the present invention, by disposing the coil spring separately from the shock absorber and disposing the coil spring on the lower A-shaped arm member, there is a disadvantage in layout of an engine or the like. Can be avoided.

According to the front suspension device of the third aspect of the present invention, by passing the axis of the shock absorber through the wheel contact point when the vehicle is viewed from the side.
Since the damping force of the shock absorber generated does not generate torque around the ground contact point of the wheel, the slip ratio at the ground contact point of the wheel (tire) is also large even when the braking force is applied. Does not change, and thus the deceleration due to braking is stabilized even on irregular roads.

Further, according to the front suspension device of the present invention, both of the connection points of the two upper link members on the wheel support member side are located forward of the vehicle body member side connection point in a plan view of the vehicle. , The upper side of the wheel is pulled inward in the vehicle width direction with the turning, and the camber of the turning outer wheel is corrected in the negative direction, thereby improving the turning performance. Therefore, since the camber characteristics of the turning outer wheel can be secured, it is possible to design a suspension in which a simple change in stroke-camber characteristics is suppressed. As a result, there is an advantage that a change in camber caused by mere bounce when the vehicle travels on an irregular road without turning is reduced, and this leads to an improvement in straightness on the irregular road.

Further, according to the front suspension device of the present invention, the distances between the connection points of the two upper link members on the wheel support member side and the virtual intersections are equal or substantially equal. Setting the distance from the virtual kingpin axis to the connection point on each wheel support member side of the two upper link members is made equal or substantially equal, and thereby the front suspension according to claim 4 is set. In the device, the amount of retraction above the wheel at the time of steering is equal or substantially equal at the connection point of each of the two upper link members on each wheel support member side, so that either is larger or smaller. Has no effect on the toe change.

According to the front suspension device of the present invention, the connection point with the wheel support member is located at the upper link member at the front of the vehicle, and the connection point with the wheel support member is located at the rear of the vehicle. By arranging above the upper link members, the respective connection points of the two upper link members on the wheel support member side can be arranged along the outer circumferential arc of the rear half of the tire. The capacity of the wheel house for storing the wheels can be reduced.

Further, according to the front suspension device of the present invention, the connection point of the bush used for the connection point with the upper link member at the connection point with the wheel support member is located at the front of the vehicle. By setting the axial rigidity of the member to be lower than that of the bush used for the connection point of the other upper link member, the connection point with the wheel support member is located in front of the vehicle due to the torque around the axle during braking. Since the entire upper link member moves outward in the vehicle width direction, and the connection point with the wheel support member at the wheel support member side of the upper link member at the rear of the vehicle is drawn inward in the direction, the relative position is relatively high. As a result, the wheels at the time of braking are used as toe-outs, thereby improving the stability particularly during turning braking.

Further, according to the front suspension device of the present invention, the wheel supporting member can be swung by using two lower link members instead of the lower A-shaped arm member. By connecting the lower input point of the shock absorber on a straight line connecting the intersection of the two lower link members and the virtual intersection, Lower link member enables the same alignment as a so-called double-pivot type suspension having a so-called A-shaped arm divided shape, so that the intersection of the two lower link members can be more outwardly located in the vehicle lateral direction. The degree of freedom of setting the virtual kingpin axis connecting this intersection and the connection point between the shock absorber and the wheel support member is increased, and this is set to an appropriate state, that is, the key is set. Gupin inclination can be further improved appropriately set to riding comfort and steering stability of the.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. Here, among the suspension devices for the steered wheels of the present invention, which are implemented by being inverted to the front left and right wheels of a front-engine front-wheel steering vehicle, a front suspension device for a front left wheel will be particularly described. Of course, for the front right wheel, the drawing may be reversed, and “right” in the description may be replaced with “left” and “left” may be replaced with “right”.

FIG. 1 is a perspective view showing a schematic structure showing a first embodiment of the present invention. In the drawing, reference numeral 1 denotes a wheel supporting member for rotatably supporting a front wheel 2 shown schematically, An axle portion 1a forming an axle of a front wheel is formed in the lower portion, and a lower A arm (lower A-type arm member) 4 is connected to a lower end portion 1b thereof via a ball joint 3. The upper end 1c of the wheel support member 1 is once raised up to a position above the tire of the front wheel 2, and further curved outwardly in the vehicle width direction, that is, toward the upper side of the tire. , Each a ball joint 5,
6 upper links (upper link member) via 6
7, 8 are connected. Further, a tie rod (tie rod member) 10 is connected via a ball joint 9 to a tie rod support portion 1d protruding from the lower end 1b of the wheel support member 1 to the rear of the vehicle. A ball joint 11 is provided on a shock absorber support portion 1e projecting inward from the center of the wheel support member 1 in the vehicle width direction.
Through the piston rod 12 of the shock absorber 12
The lower end of a is connected.

The lower A arm 4 of this embodiment is disposed extending in the vehicle width direction, and its outer end in the vehicle width direction is rotatably connected to the lower end portion 1b of the wheel support member 1 via the ball joint 3. The inner end is bifurcated, and each end is connected to a vehicle body member 13 such as a side member via elastic bushes 21 and 22 to form an A-shaped arm having an approximately A shape when viewed from a plane. . Accordingly, the lower arm 4 allows the wheel support member 1 to move in the vertical direction, ie, the bounding and the rebound, but prevents the wheel support member 1 from moving in the front-rear direction. The so-called wind-up angle change of the member 1 can be suppressed. Also, the lower end 1b of the wheel support member 1 and the lower arm 4 are rotatable via the ball joint 3,
That is, since the vehicle is connected so as to be able to steer, the connection point S constitutes one point below the virtual kingpin axis described later.

On the other hand, the two upper links 7, 8
Is disposed above the tire and at a so-called torsional position that does not cross or be parallel to each other, and that each of the outer ends in the vehicle width direction is connected to the wheel support via ball joints 5 and 6, respectively. The upper end 1c of the member 1 is connected, and each inner end is connected to a vehicle body member (not shown) such as a suspension member via elastic bushes 14 and 15. Since these upper links 7 and 8 are in the twisted position, the upper link 7 in FIG. 1 is connected to the upper end 1c of the wheel support member 1 in front of the vehicle with respect to the upper link 8 in FIG. Therefore, the wheel support member 1
Hereinafter, the upper link 7 whose connection point with the vehicle front is referred to as a first upper link 7, and the other upper link 8 whose connection point with the wheel support member 1 is the rear of the vehicle is referred to as a second upper link 8. Show. The substantial connection points of the upper links 7 and 8 with the wheel support members 1 are the connection points E and F by the ball joints 5 and 6, respectively, but these upper links 7 and 8 are fixed. The fulcrum at which the wheel support member 1 rotates when it is in the middle is the midpoint of the shortest distance between the two upper links 7, 8, as shown in FIG. Therefore, assuming that the midpoint of the shortest distance between the two upper links 7, 8 is referred to as a virtual intersection of the two upper links 7, 8, this virtual intersection R is the upper side of a virtual kingpin axis described later. Constitutes one point. The connection points that are considered to connect the upper links 7 and 8 and the vehicle body member geometrically via the bushes 14 and 15 are denoted by J and I, respectively. In the present embodiment,
The first upper link 7, that is, the connection point E with the wheel support member 1 is located at the front of the vehicle with respect to the connection point F of the other second upper link 8 with the wheel support member 1.
Are disposed above the second upper link 8. This is because while the first upper link 7 is connected to the wheel supporting member 1 from the upper surface of the wheel supporting member 1 by the ball joint 5, the second upper link 8
Is clearly connected to the wheel supporting member 1 from the lower surface of the wheel supporting member 1 by the ball joint 6. And in this embodiment, each connection point E, F of the two upper links 7, 8 with the wheel support member is:
In both cases, the connecting points J and I with the vehicle body members are located forward of the vehicle. Further, in the present embodiment, the wheel support member 1 is moved from a virtual intersection R between the two upper links 7 and 8.
Are set so that the distances to the connection points E and F are equal or substantially equal to each other.

The shock absorber 11 has a lower end portion of a piston rod 12a rotatably connected to a shock absorber support portion 1e of the wheel support member 1 via a ball joint 11, and a cylinder tube 12b. The upper end is attached to a vehicle body member (not shown) via a mounting plate (not shown) or a mount rubber. The point at which the ball joint 11 connects the shock absorber 15 to the vehicle body-side member is referred to as point O. By the way, this connection point O is the shock absorber 1
Needless to say, this is the lower input point of 2. And
In the present embodiment, the lower end input point O of the shock absorber 12 is defined by a virtual intersection R of the two upper links 7 and 8 and a connection point S of the lower A arm 4 on the wheel support member 1 side.
Are arranged on a virtual kingpin axis L passing through the center. The axis of the shock absorber 12 is
It is set so as to pass through the ground point of the wheel 2.

The tie rod 10 has an outer end rotatably connected to the wheel supporting member 1 through the ball joint 9 and an inner end connected to a steering device (steering device) (not shown). Are linked.
Of these, the point of connection with the wheel support member 1 is also referred to as point H, and the point of connection with the steering device is also referred to as point G.

In the present embodiment, the coil spring 16 is not coaxial with the shock absorber 12, but is separately provided. The lower end of the coil spring 16 is connected to the lower A arm 4, and the upper end is connected to the body member. 13.

Next, the operation of the above embodiment will be described. FIG. 3A is a skeletal diagram of the suspension device having the above configuration in a perspective view, and FIG. 3B is a skeletal diagram of the suspension device in a front view of the vehicle. Each connection point, intersection, input point, etc., did not use the signs of the bush or ball joint, but used only the signs that directly represent them.

As described above, in the present embodiment, the virtual intersection R of the two upper links 7 and 8 and the lower A arm 4
The input point O of the lower end of the shock absorber 12 is arranged on a straight line connecting the wheel support member connecting point S, that is, the virtual kingpin axis K. Therefore, the lever ratio of the shock absorber 12 is "1", that is, the ratio of the stroke of the wheel to the stroke of the shock absorber is "1". The difference between the shock absorber damping force and the damping force is not input to the vehicle body members, and the amount of input to the vehicle body is reduced to ensure riding comfort, especially on irregular roads where transient vertical inputs frequently occur. Can be. In addition to the simple structure,
Since separate members such as a kingpin and a kingpin bearing for independently configuring the kingpin shaft are not required, this is advantageous in terms of layout, weight and cost.

However, as described above, the shock absorber 12
In order to arrange the lower end input point O of the shock absorber 12 on the virtual kingpin axis K while setting the lever ratio to "1", the wheel support is substantially performed without an intermediate link member or arm member. The lower end input point O of the shock absorber 12 must be directly connected to the member 1. For this reason, in the upper wish low mount type double wishbone type suspension device in which the upper link is located inside the inner periphery of the tire, it is substantially difficult to achieve both the layout of the shock absorber and the layout of the upper link. On the contrary, the upper link is located above the tires, that is, the upper link high mount type double wishbone type suspension device is required. Also, the virtual kingpin axis described above requires the same kingpin tilt angle as that of a general front suspension device, and the upper point of the upper link constituting the virtual kingpin axis is located further inward in the vehicle width direction than the wheel center line, for example. It is in. Therefore, it is possible to configure the kingpin shaft upper point as a substantial connection point, for example, as in the above-mentioned A-arm, but in such a case, the actual length of the upper arm becomes too short, As a result, the upper portion of the wheel is more greatly drawn inward in the vehicle width direction than the lower portion of the wheel, so that the camber greatly changes to the negative side with each wheel stroke, and a desired ground camber characteristic cannot be obtained. I do. Therefore, in order to obtain the actual length of the upper link and secure the desired ground camber characteristics, as described above, the two upper links are arranged at the twisted position, and the virtual intersection R of the virtual kingpin axis is provided at the virtual intersection R. It is necessary to configure the upper point.

On the other hand, even if these conditions are satisfied, for example, if the shock absorber and the coil spring are arranged coaxially, as shown in FIG. 11, the shock absorber and the coil spring are arranged so as to avoid interference between the coil spring and the wheel. The axis of the coil spring must be largely tilted inward in the vehicle width direction, and the connection point between the two and the vehicle body member must also be significantly moved inward in the vehicle width direction. However, in the case of the introductory engine according to the present embodiment, this greatly restricts the engine room, which is extremely disadvantageous in layout. Therefore, the coil spring is provided separately from the shock absorber, and is disposed substantially on the low A arm to avoid layout problems.

Next, FIG. 4 shows a schematic skeleton diagram as viewed from the side of the vehicle. Here, it can be seen that the virtual kingpin axis K is given an appropriate caster. The axis L of the shock absorber 12 is set so as to pass through the ground point C of the wheel 2. In the case where the axis L of the shock absorber 12 is disposed in this manner, as shown in FIG. 5, for example, even when a vertical force is input from a wheel ground point C on an irregular road during braking, the damping force D of the shock absorber 12 is provided. / F is
No torque is generated around the wheel contact point C. Therefore,
Even when the shock absorber 12 generates the damping force D / F, the slip ratio at the wheel contact point C does not change, so that the deceleration effect by braking is stable and even when there is an up / down input on an irregular road or the like. The braking deceleration becomes stable.

Next, the relationship between the two upper links 7 and 8 and the wheel 2 in a plan view of the vehicle is shown as a skeleton diagram in FIG. As described above, in the present embodiment, both the wheel supporting member-side connecting point E of the first upper link 7 and the wheel supporting member-side connecting point F of the second upper link 8 are both from the vehicle body member-side connecting points J and I. It is designed to be ahead of the vehicle. The connection points E and F of the upper links 7 and 8 on the wheel support member side are:
Both are located outside the virtual intersection R, which is the upper point constituting the virtual kingpin axis K, in the vehicle width direction. Therefore, as shown in FIG. 6B, when steering is performed by operating the tie rod 10 with the steering device, for example, when turning the wheel to the right, the steering device side connection point G of the tie rod 10 is pushed outward in the vehicle width direction. The connection point H of the tie rod 10 on the wheel supporting member side moves forward of the vehicle around the virtual intersection R constituting the virtual kingpin axis upper point. Along with this,
The two upper links 7 and 8 try to rotate about the vehicle body member side connection points J and I, and as a result, the wheel support member side connection point E located forward of the vehicle from the vehicle body member side connection points J and I. , F are both drawn inward in the vehicle width direction while moving forward of the vehicle. As a result, in particular, the camber of the turning outer wheel is corrected in the negative direction and the turning performance is improved, so that it is possible to suppress a simple change in the stroke-camber characteristic, and thereby, when the vehicle passes through an irregular road without turning. Since the change in camber caused by a simple bounce can be reduced, the running stability when traveling straight on an irregular road is improved. Further, as in the present embodiment, from the virtual intersection R of the two upper links 7 and 8 to the connection points E and F on both wheel support member sides.
If the distances from the virtual kingpin axis K to the respective wheel supporting member side connection points E and F of the two upper links 7 and 8 can be equalized or substantially equalized. . At this time, two upper links 7, 8
Although there is no significant change in the height direction even if it is in the twisted position, the connection points E and F of the two upper links 7 and 8 on the wheel support member side are set inward in the vehicle width direction. The amount of pull-in is equal or substantially equal, and there is no influence on the toe change caused by either being large or small.

As shown in FIG. 7, an appropriate caster is provided to the virtual kingpin axis K as described above, and the two upper links 7 constituting the virtual kingpin axis upper point above the tire. , 8 are located slightly behind the wheel center point in the vehicle. Therefore, the first upper link 7, that is, the wheel support member connection point E is located at the wheel support member side connection point E of the upper link 7 in front of the vehicle.
Needs to be above the wheel supporting member side connection point F of the second upper link 8 at least along the outer circumferential arc of the rear half of the tire. In the present embodiment, by disposing the first upper link 7 above the second upper link 8, the two wheel support member side connection points E and F are arranged outside the outer circumferential arc of the rear half of the tire, Thus, the capacity of the wheel house that houses the wheels 2 including the upper links 7, 8 and the like can be reduced.

Next, a second embodiment of the front suspension device of the present invention will be described with reference to FIG. FIG. 8A is a skeletal diagram of the suspension device of the present embodiment in a perspective view, and FIG. 8B is a skeletal diagram of the suspension device in a front view of the vehicle. The present embodiment is different from the first embodiment only in that the lower A arm 4 is replaced by two lower links 17 and 18, and other equivalent components are denoted by the same reference numerals. Further, as in FIG. 3, the connection points, intersections, input points, etc. do not use the signs of the bush or ball joint, but use only the signs that directly represent them.

In the present embodiment, the two lower links 17 and 18 used in place of the lower A arm are connected to the lower end 1 of the wheel support member 1 at two different points M and N on the same plane.
b, was rotatably connected using a ball joint (not shown) or the like. Thus, the two lower links 17, 18
Is connected to the wheel support member 1 at two different points, the lower point of the virtual kingpin shaft is the intersection of the axes of the two lower links 17 and 18, so that the lower A arm 4 substantially connected by a ball joint Than the wheel support member side connection point of
The virtual kingpin shaft lower point can be set outside in the vehicle width direction. For this reason, as is well known, a negative scrub can be performed, and for example, there is an advantage that the braking stability is improved by making the front wheels slightly toe-out during braking.

In the front suspension of the present invention, in particular, the first upper link, that is, the cylindrical bush used for connecting the upper link 7 at the wheel supporting member side connecting point E to the upper link 7 located on the front side of the vehicle and the vehicle body member. 14, the rigidity of the portion corresponding to the axis of the first upper link 7 may be lower than that of the bush 15 used to connect the second upper link 8 to the vehicle body member. When doing so, at the time of braking, both the connection points E and F of the upper links 7 and 8 on the wheel supporting member side receive a forward force due to the braking torque around the axle. At this time, as shown in FIG. 2nd with uniform high bush rigidity
The wheel support member-side connection point F of the upper link 8 is drawn inward in the vehicle width direction with the rotation of the link member about the vehicle body member-side connection point I, while the first upper link 7 is Bush 14 in the axial direction of the link member
Since the rigidity of the first upper link 7 is low,
As a result, the entire vehicle moves to the front of the vehicle and to the outside in the vehicle width direction at the same time. As a result, the wheels relatively move in the toe-out direction at the time of braking, and there is an advantage that the stability during turning braking is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an outline of a first embodiment of a front suspension device of the present invention.

FIG. 2 is an explanatory diagram of an upper point of a virtual kingpin axis formed by two upper link members of FIG. 1;

FIG. 3 is a skeletal view for explaining geometric components in the front suspension device of FIG. 1;

FIG. 4 is a configuration explanatory view showing only a shock absorber, a virtual kingpin shaft, and wheels extracted from FIG. 3;

FIG. 5 is an operation explanatory view of the configuration of FIG. 4;

FIG. 6 is an explanatory drawing in which only wheels and two upper link members are extracted from FIG. 3;

FIG. 7 is an explanatory diagram in which only two upper link members and wheels are extracted from FIG. 3;

FIG. 8 is a skeleton diagram showing an outline of a second embodiment of the front suspension device of the present invention.

FIG. 9 is an operation explanatory view when the bush of the upper link member at the rear of the vehicle is changed in the front suspension device of the present invention.

FIG. 10 is a skeleton front view for explaining the operation of a conventional front suspension.

FIG. 11 is an explanatory diagram when a shock absorber and a coil spring are arranged coaxially.

[Explanation of symbols]

1 is a wheel support member 2 is a front wheel 3 is a ball joint 4 is a lower A arm (lower A-type arm member) 5 is a ball joint 6 is a ball joint 7 is an upper link (upper link member) 8 is an upper link (upper link member) 9 is a ball joint 10 is a tie rod (tie rod member) 11 is a ball joint 12 is a shock absorber 13 is a vehicle body member 14 is a bush 15 is a bush 16 is a coil spring 17 is a lower link (lower link member) 18 is a lower link (lower link member) E is a connection point on the wheel support member side in front of the vehicle by the upper link F is a connection point on the wheel support member side in the rear of the vehicle by the upper link G is a connection point on the steering device side by the tie rod H is a connection point on the wheel support member side by the tie rod J is The upper link Body member side connection point I is a vehicle body member side connection point in front of the vehicle by an upper link K is a virtual kingpin axis M is a wheel support member side connection point by a lower link N is a wheel support member side connection point by a lower link O is a shock absorber Lower input point R is a virtual intersection of the two upper links S is a connection point on the wheel support member side by the lower arm (the lower point of the virtual kingpin axis)

Claims (8)

[Claims] 1. An upper end portion of a wheel supporting member located above a tire is swingably connected to a vehicle body member via two upper link members, and a lower end portion of the wheel supporting member is a lower portion. In a front suspension device which is swingably connected to a vehicle body member via an A-shaped arm member and a tie rod member, the two upper link members are set in a twisted position, and a virtual intersection thereof and a wheel of the lower A-shaped arm member are provided. A front suspension device wherein a lower end input point of a shock absorber is arranged on a straight line connecting to a support member side connection point. 2. The front suspension device according to claim 1, wherein a coil spring is disposed on the lower A-shaped arm member. 3. The front suspension device according to claim 1, wherein an axis of the shock absorber as viewed from the side of the vehicle body passes through a wheel contact point. 4. The vehicle according to claim 1, wherein both of the connection points of the two upper link members on the wheel support member side are arranged in front of the vehicle relative to the connection points on the vehicle body member in plan view of the vehicle.
The front suspension device according to any one of the above. 5. The front suspension according to claim 4, wherein a distance between each of the two link members on the wheel support member side and the virtual intersection is set to be equal or substantially equal. apparatus. 6. An upper link member having a connection point with the wheel support member at the front of the vehicle and a connection point with the wheel support member at an upper portion of the upper link member at the rear of the vehicle. The front suspension device according to any one of claims 1 to 5, wherein 7. A bush used at the connection point between the upper link member and the wheel support member at the connection point with the wheel support member at the front of the vehicle in the axial direction of the link member. 7. The front suspension device according to claim 1, wherein the rigidity is set lower than that of a bush used at a connection point of the other upper link member. 8. The wheel support member is swingably connected to a vehicle body member using two lower link members instead of the lower A-shaped arm member, and a lower end input point of the shock absorber is connected to the two lower link members. The front suspension device according to claim 1, wherein the front suspension device is disposed on a straight line connecting an intersection of the lower link members of the book and the virtual intersection.