JP3117530B2 - Vehicle suspension device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventionally, strut-type suspension systems and double wishbone-type suspension systems have been known as front wheel suspension devices for vehicles.

[0003] The strut type suspension device is
Since it has a small number of parts, is lightweight and inexpensive, and has excellent layout properties, it is widely used especially as a front wheel suspension device for FF type vehicles. However, in the strut type suspension device, the virtual kingpin axis which is the steering rotation axis of the wheel is a straight line connecting the connection point between the upper end of the damper device and the vehicle body and the connection point between the lower arm and the wheel support member. This is not desirable in terms of performance. That is, from the viewpoint of the performance of the vehicle, the virtual kingpin axis passes slightly inside the vehicle body than the center line in the width direction of the wheel on the rotation center line of the wheel, and has a slightly negative kingpin offset on the ground contact surface of the wheel. Ideally, it passes slightly outside the center line in the width direction of the wheels, but the virtual kingpin axis of the strut type suspension device is inclined more inward than the ideal virtual kingpin axis. .

On the other hand, in the double wishbone type suspension device, the virtual kingpin axis is a straight line connecting the connection point between the upper arm and the wheel support member and the connection point between the lower arm and the wheel support member. It is possible to approach the ideal kingpin axis by appropriately setting both connection points. However, in the case of the double wishbone type suspension device, two connection points of the upper arm and the lower arm with the vehicle body are required at each of two places in order to counter horizontal loads acting on the wheels, and other parts are arranged accordingly. Is limited. In particular, if this double wishbone type suspension device is used as a front wheel suspension device in an FF type vehicle having an engine mounted horizontally, this layout restriction becomes an important problem.

In order to combine the advantages of the conventional strut type and the double wishbone type and to eliminate the disadvantages, a number of suspension devices have been proposed.

[0006] For example, in Japanese Unexamined Patent Publication No. 2-220904, the upper arm is composed of one link member, and the lower end of the damper device is connected to the lower arm to reduce the load acting on the wheels. Have also been supported. According to this configuration, since there is only one connection point between the upper arm and the vehicle body, the degree of freedom of the layout can be increased accordingly.

[0007] In the device disclosed in Japanese Patent Application Laid-Open No. 1-136804, an intermediate member is provided between the wheel support member and the upper arm, and the lower end of the damper member is supported by the intermediate member. Further, the wheel supporting member is pivotally connected to the intermediate member via a ball joint, and the upper arm is pivotally connected only to vertically swing.

[0008]

However, such a suspension apparatus also has the following disadvantages.
That is, in the device described in Japanese Patent Application Laid-Open No. 2-220904, the lower end of the damper device is connected to the middle portion of the lower arm in the vehicle width direction. The force (damping force) generated by the damper device needs to be increased by an amount corresponding to the lever ratio. Therefore, it is necessary to increase the size of the damper device and the lower arm connected thereto, which causes an increase in weight. In the case of an FF type vehicle, a drive shaft is arranged to extend in the vehicle width direction on the rotation center line of the wheel. In order to avoid interference between the drive shaft and a damper device formed on a lower arm, a damper device is provided. It is necessary to provide a forked connecting member for passing the drive shaft between the lower end of the motor and the lower arm. Since this connecting member receives all the forces generated by the damper device, it must have a large rigidity, and it becomes large. This also has the disadvantage of increasing the weight.

Further, in Japanese Patent Application Laid-Open No. 1-136804, since the wheel supporting member and the intermediate member are connected by a ball joint, a horizontal load (lateral force, longitudinal force) acting on the wheel is damped by a damper device. In this case, two connection points of the upper arm with the vehicle body are required as in the case of the double wishbone type suspension device, and the degree of freedom in layout cannot be increased.

In view of the above circumstances, the present invention aims to improve the performance by bringing the virtual kingpin shaft closer to an ideal one, and to achieve a compact, light-weight and more flexible layout device for a vehicle. The purpose is to provide.

[0011]

Means for Solving the Problems In order to achieve the above object, the present invention has the following configuration. That is, as described in claim 1 of the claims, a wheel support member rotatably supporting a wheel, and a lower arm having one end connected to a lower end of the wheel support member and the other end connected to a vehicle body. An upper joint connected to the upper end of the wheel support member so as to be rotatable only about the vertical axis with respect to the wheel support member, an upper end connected to the vehicle body, and a lower end provided only around the front-rear axis with respect to the upper joint. A damper device connected to the upper joint so as to be rotatable, and one end supported on the front-rear axis or so as to be rotatable only about the front-rear axis with respect to the upper joint, and the other end connected to the vehicle body at one point And an upper arm connected to the upper joint at a lower end of the damper device. A pair of front and rear arms having an opening having a diameter larger than a shaft is formed, and a support member interposed in each of the openings is fitted to the front and rear shafts, so that the lower end of the damper device is in a pair. Are connected to the front-rear shaft via an arm portion and a pair of support members.

[0012]

According to the present invention, since the lower end of the damper device is connected to the upper end of the wheel support member via the upper joint and does not extend downward to near the rotation center line of the wheel, the FF type vehicle Even in this case, there is no interference between the damper device and the drive shaft, and there is no need to adopt a special structure for avoiding this interference. Also, since the vertical load acting on the wheels is input to the damper device at a ratio of approximately 1 lever ratio, it is not necessary to particularly increase the size of the damper device and the like, so that the size and weight of the device can be reduced. it can. Further, since only one connection point of the upper arm with the vehicle body is required, the degree of freedom in layout can be increased accordingly.

Further, since the camber change characteristics can be set to be substantially the same as that of the double wishbone type suspension device, the suspension performance can be improved.

Further, since a sleeve is interposed between the lower end of the damper device and the front-rear shaft, and the lower end of the damper device and the upper joint are connected via the sleeve, the lower end of the damper device is connected to the upper joint. There is no play or slippage at the connecting portion with the connecting portion, and there is an effect that the loosening of the bolts constituting the front-rear shaft or generation of abnormal noise at the connecting portion can be prevented.

Further, the lower end of the damper device is connected to the front-rear shaft via a pair of front-rear arms arranged so as to sandwich the upper joint from the front-rear direction. Is securely received by the damper device, and the vertical movement of the wheel support member is efficiently input as the expansion and contraction movement of the damper device.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show an FF according to an embodiment of the present invention.
1 shows a knuckle member as a wheel support member for rotatably supporting a wheel (front wheel) 2. A drive shaft (not shown) is provided at the center of the knuckle member 1. Is formed through the hole 3 (see FIGS. 1 and 4). 4 is a knuckle member 1
Is a lower arm that connects the lower end of the knuckle member 1 to the vehicle body, 5 is an upper arm that connects the upper end of the knuckle member 1 to the vehicle body, and 6 is a damper device including a shock absorber that buffers the vertical movement of the wheel 2.

The lower arm 4 has two front and rear link members.
The front link member 11 extends substantially linearly along the vehicle width direction. One end of the link member 11 is pivotally connected to the lower end of the knuckle member 1 via a ball joint 13, and the other end of the link member 11 is connected to a cross member 14 (see FIGS. 2 and 3) which is a vehicle body strength member. On the other hand, the shaft is vertically swingably connected via a rubber bush 15 extending in the vehicle longitudinal direction. Also, the rear link member 12
Has a curved shape, and one end of the link member 12 is located at a lower end of the knuckle member 1 at a position close to and behind a pivot point (center of the ball joint 13) of the link member 11 via a ball joint 16. Pivotally connected to the link member 12
The other end of the link member 11 at a position far away from the link member 11,
It is connected to the cross member 14 via a rubber bush 17 so as to be vertically swingable. Therefore, the link members 11,
The twelve axes intersect at a point O1 outside the vehicle body with respect to a pivot point (the center of the ball joints 13, 16) with the knuckle member 1 (see FIG. 3).

The knuckle member 1 is integrally formed with an arm 1a extending rearward from the vicinity of the drive shaft insertion opening 3 (see FIGS. 1 and 4), and a tie rod 20 of a steering device is provided at the tip of the arm 1a. Are linked. Further, an upper joint 21 is attached to an upper end of the knuckle member 1, and the upper joint 21 is connected to an upper arm 5 and a lower end of the damper device 6.

As shown in FIG. 5, the upper joint 21 has a cylindrical first boss 21a having an axis in the vertical direction, and an inner hole having a shaft hole 24d in the first boss 21a. A cylinder 24 is provided coaxially and rotatably via a sliding bush 25 made of resin. On the outer peripheral surface of the inner cylinder 24,
A cylindrical surface 24a, an upper conical surface 24b continuous with the upper end of the cylindrical surface 24a and gradually increasing in diameter as it goes upward, and a lower conical surface continuous with the lower end of the cylindrical surface 24a and gradually increasing in diameter as it goes downward 24c are formed. The inner peripheral surface of the first boss portion 21a has the sliding bushing with respect to the cylindrical surface 24a, the upper conical surface 24b and the lower conical surface 24c of the inner cylinder 24.
The cylindrical surface 21b and the upper conical surface 21c facing each other via 25
And a lower conical surface 21d. A vertical shaft 23 attached to the upper end of the knuckle member 1 and extending vertically is inserted into the shaft hole 24d of the inner cylinder 24, and
Since the upper joint 21 is fixed to the vertical shaft 23, the upper joint 21 is
Is provided rotatably only around the axis, and against a rotational force about an axis orthogonal to the vertical axis 23, the surface resistance between the outer peripheral surface of the inner cylinder 24 and the inner peripheral surface of the first boss 21a causes It is designed to resist.

One end of the upper arm 5 (the inner end of the vehicle body) is connected to a bracket 31 mounted on the cross member 14.
2 (see FIG. 2), the axis is vertically swayably connected via a rubber bush 32 extending in the front-rear direction of the vehicle body, while the other end of the upper arm 5 (outside end of the vehicle body)
A pair of branched portions 5a, 5a branched in a bifurcated manner so as to sandwich the lower end of the damper device 6 from both front and rear sides are formed.
), The distal end of each branch portion 5a is connected to the upper joint 21 via a rubber bush 33 whose axis extends in the vehicle longitudinal direction so as to be vertically swingable.

The upper end of the damper device 6 is elastically supported by the vehicle body 7 via a rubber mount 36 (see FIGS. 1 and 2). It is arranged. On the other hand, a bracket 38 is pivotally attached to the lower end of the damper device 6, and the bracket 38 has a pair of arms 38a, 38a extending bifurcated from a fitting portion to the damper device 6, and both arms 38a ,
38a are located inside the two branches 5a, 5a of the upper arm 5 and are connected to the upper joint 21 by the branches 5a, 5a.
Are connected so as to be able to swing up and down around the same axis.

The structure of the connection between the upper arm 5 (branch 5a) and the lower end of the damper device 6 (specifically, the arm 38a of the bracket 38) with respect to the upper joint 21 is shown in detail in FIGS.

As is apparent from FIGS. 6 and 7, the upper joint 21 has a cylindrical second boss 21e having an axis in the front-rear direction, and inside the second boss 21e,
An inner cylinder 40 having a shaft hole 40d is provided coaxially and rotatably via a sliding bush 41. On the outer peripheral surface of the inner cylinder 40, a cylindrical surface 40a, and a front conical surface 40b which is continuous with the front end of the cylindrical surface 40a and gradually increases in diameter as it goes forward,
A rear conical surface 40c is formed which is continuous with the rear end of the cylindrical surface 40a and gradually increases in diameter toward the rear. The inner peripheral surface of the second boss portion 21e has a cylindrical surface 40a of the inner cylinder 40.
A cylindrical surface 21f, a front conical surface 21g, and a rear conical surface 21h, which face the front conical surface 40b and the rear conical surface 40c via the sliding bush 41, respectively, are formed.

Further, at the front end and the rear end of the shaft hole 40d of the inner cylinder 40, recesses 40e, 40e having a diameter larger by a predetermined dimension than the inner diameter of the shaft hole 40d are formed coaxially. 40
The distal ends of the cylindrical portions 42a of the sleeves 42, 42, which will be described later, are fitted in the e and 40e, respectively. The sleeve 42 has a cylindrical portion 42a having an inner diameter substantially equal to the inner diameter of the shaft hole 40d of the inner cylinder 40.
And a flange portion 42b formed at one end of the cylindrical portion 42a. Each arm portion 38a of the bracket 38 attached to the lower end of the damper device 6 is provided on the outer periphery of the cylindrical portion 42a.
The end of the cylindrical portion 42a of the sleeve 42 is fitted to the inner cylinder 40 of the upper joint 21, so that the front and rear end surfaces of the arm portion 38a are connected to the end surface of the flange portion 42b of the sleeve 42. And the side end surface of the inner cylinder 40, respectively, whereby the arm portion 38a and the inner cylinder 40
Are rigidly connected via the.

The shaft hole 40d of the inner cylinder 40 and the sleeves 42, 42 fitted at the front and rear ends thereof have a single bolt-shaped front and rear shaft.
The front and rear shafts 39 have inner cylinders 33a of rubber bushes 33 attached to the distal ends of both branch portions 5a, 5a of the upper arm 5, respectively. It is inserted so as to be in contact with the end face. 33b is an outer cylinder of the rubber bush 33, and 33c is a rubber filled between the inner cylinder 33a and the outer cylinder 33b.

Thus, the inner cylinder 33a of the two rubber bushes 33, the two sleeves 42, and the upper joint 21
A nut 43 is fastened to one end of a front-rear shaft 39 that is attached through the inner cylinder 40 so that the upper joint 21, the lower end of the damper device 6, and the upper arm 5 are connected to each other by the front-rear shaft 39. It is connected so as to be relatively rotatable (up and down swingable) only around it.

The above is the configuration of the present embodiment. Next, the operation and effects of the present embodiment will be described.

When the wheel 2 is steered left and right by receiving the steering force from the tie rod 20 via the knuckle member 1, the lower end side of the knuckle member 1, that is, the instantaneous rotation center point of the lower arm 4, constitutes the lower arm 4. Book link member 11,
This is the intersection O1 between the twelve axes (see FIG. 3). Further, the instantaneous rotation center point on the upper end side of the knuckle member 1 is defined by an upper and lower shaft 23 which is a connection shaft of the knuckle member 1 with the upper joint 21.
While rotating around, the structure consisting of the damper device 6, the upper joint 21 and the upper arm 5 is connected to the vehicle body connection point at the upper end of the damper device 6 (the center point of the rubber mount 36) and the vehicle body connection point of the upper arm 5 (the rubber bush 32). (The center point of the vertical axis L2) (see FIG. 2), the intersection O2 between the axis extension line L2 of the vertical shaft 23 and the straight line L1. Therefore, the virtual kingpin axis is a straight line L3 passing through the two intersections O1 and O2. On the grounding surface of the wheel 2 passing through the inside of the vehicle body, it comes closer to an ideal one passing slightly outside the vehicle body than the center L4 in the width direction of the wheel 2 so as to have a slight negative kingpin offset (−Δ). Improvement can be achieved.

Further, the lower end of the damper device 6 is connected to the upper end of the knuckle member 1 via the upper joint 21 and does not extend downward to near the rotation center line L5 of the wheel 2, so that the damper device 6 and the drive shaft And do not interfere. Therefore, it is not necessary to adopt a special structure for avoiding the interference, and the structure can be simplified, and the device can be reduced in size and weight. Further, since the vertical load acting on the wheel 2 is input to the damper device 6 at a ratio of substantially the lever ratio of 1, the damper device 6 is required to generate a damping force corresponding to the vertical load. There is no particular need to increase the size, more miniaturization,
It is possible to reduce the weight.

Furthermore, since only one connection point of the upper arm 5 with the vehicle body is required, the degree of freedom in layout can be increased accordingly.

In addition, a sleeve 42 is interposed between the arm 38a of the bracket 38 fixed to the lower end of the damper device 6 and the front-rear shaft 39, and the arm 38a is connected to the front-rear shaft 39.
Each arm 38a and the inner cylinder 40 of the upper joint 21 are rigidly connected via a sleeve 42, respectively, and the front and rear shafts 39 are inserted through the sleeve 42 and the inner cylinder 40. The upper joint 21
There is no backlash, slippage, etc. of the connecting portion of the arm 38a with respect to, and the vibration caused by the swing of the arm 38a
Nut fastened to the front and rear shaft 39 because it is not directly transmitted to 39
There is no danger of 43 becoming loose due to vibration.

Further, before the rubber bush 33 and the front-rear shaft 39 are mounted, the inner cylinder 40 of the upper joint 21 is mounted.
Since the sub-assembly can be performed only by attaching the arm 38a at the lower end of the damper device 6 via the sleeve 42, there is an advantage that the assemblability of the suspension device is improved.

Next, the vertical shaft 23 is moved vertically (vertically).
The effect on the wheel alignment of the wheels 2 when the front-rear shaft 39 is inclined with respect to the horizontal direction or the vehicle front-rear direction will be described with reference to FIGS.

As shown in FIG. 8 (a), when the vertical shaft 23 is inclined backward with respect to the vertical direction when viewed from the side of the vehicle body,
When the wheel 2 is steered, the caster angle of the wheel 2 increases because the upper end side of the wheel 2 rotates around the vertical axis 23 (see FIG. 8B). Further, the camber angle of the wheel 2 changes in the negative direction as the caster angle increases.

As shown in FIG. 9A, when the vertical shaft 23 is inclined forward with respect to the vertical direction when viewed from the side of the vehicle body,
When the wheel 2 is steered, the caster angle of the wheel 2 decreases because the upper end side of the wheel 2 rotates around the vertical axis 23 (see FIG. 9B). In addition, the camber angle of the wheel 2 changes in the positive direction as the caster angle decreases.

As shown in FIG. 10, when the vertical shaft 23 is inclined toward the inside of the vehicle body when viewed from the vehicle front-rear direction, a change similar to that shown in FIG. The caster angle increases.

As shown in FIG. 11, when the upper and lower shafts 23 are inclined to the outside of the vehicle body when viewed from the front and rear direction of the vehicle body, the same change as in FIG. The caster angle decreases.

As shown in FIG. 12 (a), when the front-rear shaft 39 is inclined forward and upward with respect to the horizontal as viewed from the side of the vehicle body, when the wheel 2 is bumped, the upper end of the wheel 2 is
Since the wheel 2 rotates around 39, the caster angle of the wheel 2 decreases (see FIG. 12 (b)). The caster angle of the wheel 2 also decreases when the wheel 2 rebounds.

As shown in FIG. 13 (a), when the front-rear shaft 39 is inclined forward and downward with respect to the horizontal direction when viewed from the side of the vehicle body, the upper end of the wheel 2 is
Since it rotates around 39, the caster angle of the wheel 2 increases (see FIG. 13 (b)). Also, when the wheel 2 rebounds, the caster angle of the wheel 2 increases.

As shown in FIG. 14A, when the front-rear shaft 39 is inclined forward and inward with respect to the front-rear direction of the vehicle body when viewed from above the vehicle body, the upper end of the wheel 2 is By rotating around the axis 39, the caster angle of the wheel 2 decreases (see FIG. 14 (b)). The caster angle of the wheel 2 also decreases when the wheel 2 rebounds.

As shown in FIG. 15 (a), when the front-rear shaft 39 is inclined forward and outward with respect to the vehicle front-rear direction when viewed from above the vehicle body, the upper end of the wheel 2 is By rotating about the axis 39, the caster angle of the wheel 2 increases (see FIG. 15 (b)). Also, when the wheel 2 rebounds, the caster angle of the wheel 2 increases.

In the above embodiment, the upper joint 21, the upper arm 5, and the damper device 6 are used.
Is connected around one longitudinal axis 39 extending in the longitudinal direction of the vehicle body. The upper joint 21 is connected to the lower end of the damper device 6 so as to be vertically swingable around the longitudinal axis. The upper joint 21
And the damper device 6 may be pivotally mounted so as to be able to swing up and down around a connecting shaft different from the front and rear shaft connecting the damper device 6 and the damper device 6.

Further, the present embodiment is a case where the present invention is applied to a suspension device for a front wheel of an FF type vehicle, but it is needless to say that the present invention can be applied to suspension devices of various vehicles.

[Brief description of the drawings]

FIG. 1 is a perspective view of a suspension device according to an embodiment of the present invention.

FIG. 2 is a front view showing a part of the vehicle body as viewed from the front of the vehicle;

FIG. 3 is a plan view of the same.

FIG. 4 is a side view of the same.

FIG. 5 is a sectional view showing a connection structure between a knuckle member and an upper joint.

FIG. 6 is a sectional view showing a connection structure between an upper joint, an upper arm, and a damper device.

FIG. 7 is an enlarged sectional view showing a main part of FIG. 6;

FIG. 8 is an explanatory diagram for explaining an effect of a tilt of a vertical axis on a wheel alignment of a wheel;

FIG. 9 is an explanatory view of the same.

FIG. 10 is an explanatory view of the same.

FIG. 11 is an explanatory view of the same.

FIG. 12 is an explanatory diagram for explaining an effect of a tilt of a front-rear axis on a wheel alignment of a wheel;

FIG. 13 is an explanatory view of the same.

FIG. 14 is an explanatory view of the same.

FIG. 15 is an explanatory view of the same.

[Description of Signs] 1 Knuckle member (wheel support member) 2 Wheel (front wheel) 4 Lower arm 5 Upper arm 6 Damper device 11, 12 Link member 21 Upper joint 23 Vertical axis 39 Front / rear axis

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-77504 (JP, A) JP-A-2-204112 (JP, A) JP-A-3-114978 (JP, A) JP-A-2- 290707 (JP, A) JP-A-2-306810 (JP, A) JP-A-2-306808 (JP, A) JP-A 62-196708 (JP, U) JP-A 1-63506 (JP, U) (58) Field surveyed (Int.Cl. ⁷ , DB name) B60G 3/18 B62D 7/18 F16F 15/08

Claims (1)

(57) [Claims] 1. A wheel support member rotatably supporting a wheel, a lower arm having one end connected to a lower end of the wheel support member and the other end connected to a vehicle body, and a wheel support provided at an upper end of the wheel support member. An upper joint connected to the member so as to be rotatable only around the vertical axis, an upper end connected to the vehicle body, and a lower end connected to the upper joint such that the lower end is rotatable only around the front-rear axis with respect to the upper joint; One end of the damper device with respect to the front-rear axis or the upper joint .
It is supported so that it can rotate only around the longitudinal axis ,
An upper arm having a second end connected to the vehicle body at a single point; and a lower end of the damper device,
Extend independently on both sides in the front-rear direction of the
A pair of front and rear arms with a large diameter opening is formed.
And a support member interposed in each of the openings is fitted to the front-rear shaft.
As a result, the lower end of the damper device is
The front-rear shaft via a pair of arm portions and a pair of support members
A suspension device for a vehicle, wherein the suspension device is connected to the vehicle.