JP2001277828A - Front suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively utilize the reaction of a stabilizer. SOLUTION: The stabilizer 15 is connected to a transverse link 1 through a connecting rod 15. The direction of the reaction of the connecting rod 15 to the transverse link 1 through the connecting rod 15 is inclined so that the lower side is positioned at the rear in the longitudinal direction of a vehicle. In this constitution, the caster trail on a wheel bound side increases due to stabilizer reaction F.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an independent suspension type front suspension device having a plurality of lower links and a stabilizer connected to the lower links.

[0002]

2. Description of the Related Art Depending on the structure of a suspension, an end of a stabilizer may be connected to a lower link via a connecting rod. In other words, connecting and connecting the end of the stabilizer via a ball joint
The upper end of the rod is connected to extend the connecting rod downward, and the lower end of the connecting rod is connected to the lower link via a ball joint.

At this time, conventionally, the force lines connecting the center points of the upper and lower ball joints respectively connected to the upper and lower ends of the connecting rod are set to be vertical.

[0004]

As described above, since the force lines connecting the center points of the ball joints respectively connected to the upper and lower ends of the connecting rod are oriented vertically, the stabilizer generated when the vehicle rolls. The reaction force is
The input is made in the vertical direction and upward or downward with respect to the lower link.

[0005] In the case of a so-called double joint type suspension in which the lower link is composed of two lower links, the lower pivot of the virtual kingpin is set by the intersection of the link axes of the two lower links.
Since the stabilizer reaction force is input in the vertical direction with respect to the lower link, it does not contribute to the position of the lower pivot of the virtual kingpin at all.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to effectively utilize a stabilizer reaction force.

[0007]

According to a first aspect of the present invention, a wheel supporting member for rotatably supporting a wheel is provided such that two wheel-side ends of two lower links are individually provided. Connected via the ball joint of
A front suspension device in which a stabilizer is connected to one lower link of the book via a connecting rod, and a direction of a stabilizer reaction force input to the one lower link on the wheel bound side is: When viewed from the vehicle width direction, the connecting rods are arranged so as to be inclined from the vertical direction in the direction toward the rear in the front-rear direction of the vehicle body as going downward.

Next, according to a second aspect of the present invention, in the configuration according to the first aspect, the upper end of the connecting rod is connected to a stabilizer via a first ball joint, and the connecting rod is connected to the connecting rod. The lower end of the second
The lower ball link is connected to the one lower link via a ball joint, and the center point of the second ball joint is located rearward in the vehicle longitudinal direction from the center point of the first ball joint. It is.

According to a third aspect of the present invention, in the structure of the first or second aspect, the one end of the lower link is provided with a bush whose shaft is oriented in the longitudinal direction of the vehicle body. Is connected to the vehicle body side member so that it can swing up and down,
The rigidity of the bush in the axial direction is lower at the rear side in the vehicle longitudinal direction than at the front side in the vehicle longitudinal direction.

Next, according to a fourth aspect of the present invention, in the structure of the third aspect, the bush is formed by interposing an elastic body between an outer cylinder and an inner cylinder, and is formed in an axial direction. The gap between the outer peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder is continuously or intermittently widened from the front side in the vehicle longitudinal direction to the rear side when viewed in a vertical cross section along the line. It is characterized by the following.

Next, the invention described in claim 5 is different from the configuration described in any one of claims 1 to 4 in that the one lower link is a lower link on the front side in the vehicle longitudinal direction. It is a feature.

[0012]

According to the first or fifth aspect of the present invention, the following effects can be obtained. That is, when the vehicle body rolls, on the wheel bound side, a stabilizer reaction force that pushes one lower link downward through the connecting rod is input to the lower link. At this time, since the direction of the stabilizer reaction force is inclined rearward from the vertical direction, the stabilizer reaction force has a horizontal component component toward the rear of the vehicle body in the front-rear direction. , And is pushed backward in the vehicle longitudinal direction. As a result, the bush provided at the end of the lower link on the vehicle body side is deformed, and the mounting point on the vehicle side of the lower link is displaced rearward in the vehicle longitudinal direction relative to the mounting point on the wheel side, and the lower link is displaced. The receding angle increases. As a result, the lower pivot of the king pin formed by the intersection of the link axes of the two lower arms moves forward in the vehicle longitudinal direction, and the caster rail on the wheel bound side increases, that is, the self-aligning torque of the wheel on the bound side increases. As a result, the steering stability at the time of turning of the vehicle and at the time of traveling on uneven road surface is improved.

At the time of turning, the caster rail tends to decrease on the turning inner wheel due to the effect opposite to the above, but the value of the self-aligning torque is also small since the ground contact load is smaller than on the turning outer wheel. As described above, since the turning outer wheel side is dominant for the vehicle, it is sufficient to pay attention to the turning outer wheel side. According to the second or fifth aspect of the present invention, simply by disposing the second ball joint behind the first ball joint in the front-rear direction of the vehicle body, the second ball joint is input to one lower link on the bound side. When the stabilizer reaction force is viewed from the vehicle width direction, the stabilizer reaction force is set to be inclined from the vertical direction so as to be directed rearward in the vehicle front-rear direction as it goes downward, so that the effect of the invention according to claim 1 can be obtained.

According to the third or fifth aspect of the present invention, when the bush constituting the vehicle body-side mounting portion of one of the lower links is viewed along the axial direction of the bush, the front side in the vehicle front-rear direction. Because the rear side has lower rigidity than
When the load toward the rear in the vehicle longitudinal direction is input to the connecting rod mounting point of the lower link,
As compared with the case where the rigidity of the bush along the axial direction is uniform, the outer cylinder is more easily inclined with respect to the inner cylinder, and the caster rail is more easily increased by the wheels on the bound side.

Further, by adopting the invention according to claim 4 or claim 5, the effect according to claim 3 can be obtained only by specifying the shape of the inner cylinder or the outer cylinder.

[0016]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the left wheel side of the front suspension device according to the present embodiment. In the front suspension device of the present embodiment,
The lower link includes a transverse link 1 extending in the vehicle width direction and a compression rod 2 disposed behind the transverse link 1.

As shown in FIG. 2, the transverse link 1 has a wheel side end connected to a lower portion of a knuckle spindle 4 via a ball joint 3 and a vehicle body side end having an axis directed in the vehicle longitudinal direction. It is connected to the vehicle body side member via a bush 5 so as to be vertically swingable. The knuckle spindle 4 forms a wheel supporting member that rotatably supports the wheel.

As shown in FIG. 3 which is a longitudinal sectional view along the axial direction, the bush 5 has an elastic body 5c interposed between an inner cylinder 5a and an outer cylinder 5b. Side is fixed to the transverse link 1 and the inner cylinder 5a
The side is fixed to a mount bracket 7 of the vehicle body side member through a mounting bolt 6. However, the shape of the inner cylinder 5a is such that at least at a portion radially opposed to the outer cylinder 5b, the wall thickness is continuously reduced toward the rear in the front-rear direction of the vehicle body and formed into a deformed shape having a tapered inner surface. Have been. As a result, as shown in FIG. 3, in the longitudinal section along the axial direction, the radial interval between the outer diameter surface of the inner cylinder 5a and the inner diameter surface of the outer cylinder 5b becomes larger toward the rear in the vehicle longitudinal direction. It becomes wider continuously. As a result, the rigidity of the bush 5 along the axial direction is set to be lower on the rear side than on the front side in the vehicle longitudinal direction.

The compression rod 2 is
As shown in FIGS. 1 and 4, the wheel-side end is connected to the knuckle spindle 4 via a ball joint 8, and the vehicle-body-side mounting portion 2a is connected to the ball joint 8 (wheel-side) when viewed from the vehicle width direction. It is connected to the vehicle body side member at a position rearward in the vehicle longitudinal direction from the position of the mounting portion). In addition, an extension member 9 is provided above the knuckle spindle 4.
, The wheel-side end of the upper link 10 composed of the A-arm is connected via a ball joint 11 to form an upper pivot K2 of the kingpin K. Reference numeral 12 indicates a shock absorber, and reference numeral 13 indicates a tie rod of a steering device.

As shown in FIGS. 1 and 5, the end of the stabilizer 14 whose main body extends in the vehicle width direction is located at an intermediate position in the extending direction of the transverse link 1 via a connecting rod 15. It is connected to. More specifically, as shown in FIG. 6, the connecting rod 15 has an upper end connected to an end of the stabilizer 14 via a first ball joint 16 and extends downward, and has a lower end connected to a second end. The transverse link 1 is connected to a side surface of the transverse link 1 facing the front of the vehicle via a ball joint 17.

However, when viewed from the vehicle width direction, the center point P2 of the second ball joint 17 is set to be offset rearward in the vehicle longitudinal direction with respect to the center point P1 of the first ball joint 16. Here, the center point P2 of the second ball joint 17 is disposed close to the link axis R1 of the transverse link 1, and the link axis R is applied to the transverse link 1 by the stabilizer reaction force F.
Unnecessary twisting around 1 and R2 is suppressed.

Next, the operation and action of the front suspension having the above-described configuration will be described. In the front suspension having the above configuration, both link axes R1 and R2 of the transverse link 1 and the compression rod 2 are provided.
The intersection of R2 is the lower pivot K1 of the kingpin, and the upper and lower lines connecting the lower pivot K1 and the wheel-side attachment point (upper pivot K2) of the upper link 10 become the virtual kingpin K. In the present embodiment, as shown in FIG.
A positive caster angle θ is set.

When the vehicle equipped with the front suspension turns and the turning outer wheel 20 bounces and the turning inner wheel rebounds, the stabilizer 14 operates. Accordingly, on the turning outer wheel 20, the stabilizer reaction force F directed downward with respect to the transverse link 1 is generated.
Is entered. However, the center point P1 of the second ball joint 17 is different from the center point P1 of the first ball joint 16
2 is offset rearward in the vehicle body front-rear direction, the stabilizer reaction force F is applied rearward in the vehicle body front-rear direction because the stabilizer reaction force F is applied in a direction inclined such that the lower side faces rearward in the vehicle body front-rear direction with respect to the vertical direction. It has a horizontal component F1.

As a result, on the turning outer wheel 20 side, the middle of the transverse link 1 in the extending direction (near the wheel side) is pushed rearward in the vehicle longitudinal direction by the stabilizer reaction force F. At this time, since the ball joint 3 is used as a mounting point of the transverse link 1 on the wheel side, the horizontal link force F1 hardly displaces rearward in the vehicle longitudinal direction. ,
Because of the elastic support via the bush 5, the link axis of the transverse link 1 is displaced relatively rearward in the vehicle longitudinal direction with respect to the wheel-side attachment point, and the link axis of the transverse link 1 is inclined rearward as R1 '. The sweepback angle α of the transverse link 1 increases by the amount.

As a result, both link axes R1, R2 of the transverse link 1 and the compression rod 2
Is moved forward in the vehicle longitudinal direction as shown by K1 → K1 ′, that is, the caster trail (caster angle) increases by δT. As a result, the steering reaction force is improved due to the increase in the self-aligning torque on the turning outer wheel 20 side, and the vehicle steering stability is improved.

Here, on the turning inner wheel side, the action opposite to that of the turning outer wheel 20 side works, and the stabilizer reaction force works in the direction to decrease the trail, but the ground contact load is smaller than that of the turning outer wheel side. That is, the turning outer wheel 20 side is dominant as the vehicle, and the action of the stabilizer reaction force F on the outer wheel 20 side may be noted as described above. Further, in the present embodiment, the bush 5 constituting the vehicle body-side attachment point of the transverse link 1 is in the bush axial direction (vehicle longitudinal direction).
, The rigidity on the rear side is set lower than that on the front side in the vehicle front-rear direction, so that the horizontal component F1 of the stabilizer reaction force F is smaller than when rigidity along the bush axis direction is uniform.
Therefore, the attachment point of the transverse link on the vehicle body is
Further, it is displaced rearward in the vehicle longitudinal direction. That is, the caster rail is further increased, and the self-aligning torque on the turning outer wheel side is increased, so that the steering reaction force is further improved, and the vehicle steering stability is improved.

In the above embodiment, the rigidity of the bush 5 in the axial direction is set lower on the front side in the vehicle longitudinal direction by making the inner cylinder 5a side deformed. It is not limited to this. For example, on the side of the outer cylinder 5b, in the vertical cross-sectional shape, the thickness is set so as to become thinner toward the rear in the vehicle longitudinal direction, and the inner and outer cylinders 5a, 5b
The radial gap between the two is made wider toward the rear in the vehicle longitudinal direction, or a rear portion in the vehicle longitudinal direction of the elastic body 5c is provided to reduce the rigidity of the rear side. The rigidity of the rear side may be set low.

Further, the overall structure of the suspension is not limited to the above configuration. In short, the present invention is applicable as long as the lower link is composed of two links, and the stabilizer is connected to one of the lower links.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view illustrating a front suspension according to an embodiment based on the present invention.

FIG. 2 is a diagram showing a transverse link according to an embodiment according to the present invention.

FIG. 3 is a cross-sectional view showing a structure of a bush according to the embodiment according to the present invention.

FIG. 4 is a schematic plan view showing an arrangement of a lower link according to the embodiment according to the present invention.

FIG. 5 is a diagram showing a relationship between a kingpin and a trail according to the embodiment of the present invention, as viewed from a vehicle width direction.

FIG. 6 is a view showing an arrangement of connecting rods according to the embodiment of the present invention, as viewed from a vehicle width direction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Transverse link 2 Compression rod (lower link) 3 Ball joint (Wheel side attachment part of transverse link) 4 Knuckle spindle (wheel support member) 5 Bush 5a Inner cylinder 5b Outer cylinder 5c Elastic body 6 Mounting bolt 7 Mounting bracket ( 8 Ball joint (Wheel side attachment part of compression rod) 10 Upper link 11 Ball joint (Wheel side attachment part of upper link) 12 Shock absorber 13 Tie rod 14 Stabilizer 15 Connecting rod 16 First ball joint 17 First No. 2 ball joint P1 Center point of first ball joint P2 Center point of second ball joint K Kingpin K1 Lower pivot K2 Upper pivot T Caster rail δT Trail increase F Stabilizer reaction force F1 Horizontal component R1 Link axis of transverse link R1 Link axis after displacement R2 Link axis of compression rod α Sweep angle θ Castor angle

Claims (5)

[Claims] An end of two lower links connected to a wheel supporting member rotatably supporting wheels via respective ball joints, and one of the two lower links is connected to one of the lower links. A stabilizer connected to the stabilizer via a connecting rod, wherein the direction of the stabilizer reaction force input to the one lower link on the wheel bound side is downward when viewed from the vehicle width direction. A front suspension device wherein the arrangement of the connecting rods is set so that the connecting rods are inclined from a vertical direction in a direction toward the rear of the vehicle in the front-rear direction as the vehicle heads. 2. An upper end of the connecting rod is a first one.
The lower end of the connecting rod is connected to one lower link via a second ball joint, and the lower end of the connecting rod is connected to the lower link via a second ball joint.
The front suspension device according to claim 1, wherein a center point of the second ball joint is located rearward in a vehicle longitudinal direction with respect to a center point of the ball joint. 3. The vehicle body-side end of the one lower link,
2. The vehicle according to claim 1, wherein the shaft is connected to the vehicle body-side member via a bush extending in the vehicle longitudinal direction, and the rigidity of the bush along the axial direction is lower at the rear side in the vehicle longitudinal direction than at the front side in the vehicle longitudinal direction. Or the front suspension device according to claim 2. 4. The bush has an elastic body interposed between an outer cylinder and an inner cylinder. When viewed in a longitudinal section along the axial direction, the bush is located between the outer cylinder and the inner cylinder. 4. The front suspension device according to claim 3, wherein the radial interval increases continuously or intermittently from the front to the rear in the vehicle longitudinal direction. 5. The front suspension device according to claim 1, wherein the one lower link is a lower link on the front side in the vehicle longitudinal direction.