JP3180833B2 - 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 suspension device for a vehicle, and more particularly to a suspension device including an upper arm, a lower arm, and a shock absorber, which is intermediate between a strut type suspension and a double wishbone type suspension device.

[0002]

2. Description of the Related Art Conventionally, strut suspensions and double wishbone suspensions have been widely put into practical use as vehicle suspension devices. However, strut suspensions have a small number of parts and are small and simple in structure. There are problems such as a large kingpin offset and difficulty in increasing camber rigidity.
There is a high degree of freedom in geometrical design with respect to camber change and tread change, and the kingpin offset can be made relatively small, but there is a problem that a large installation space is required. Therefore, Japanese Patent Laid-Open Publication No.
JP-A-6-128207, JP-A-57-209408 and JP-B-58-55921 are provided with an upper arm and a lower arm oriented in the vehicle width direction, and a shock absorber. There has been proposed a suspension device (hereinafter, referred to as a strut-improved suspension) in which the inner end of the upper arm is attached to the shock absorber main body and the upper end is pivotally attached to the shock absorber body.

[0003]

When the double wishbone suspension is applied to the front wheels, interference between the upper arm and the front wheels occurs, making it difficult to secure the maximum steering angle. Since the ends are connected to the vehicle body, there are many connection points to the vehicle body side, and there is a problem that the layout is deteriorated. In the improved strut suspension described in the above publication, the amount of rise of the shock absorber main body is smaller than the amount of rise of the wheel at the time of bumping, and a certain degree of camber characteristics is secured by increasing the inclination angle of the upper arm. However, since the upper arm is attached to the shock absorber, it is difficult to sufficiently increase the camber rigidity.

SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle suspension apparatus which is excellent in layout, can secure camber rigidity, can secure sufficient camber control performance, and can use a high caster at the time of bumping. .

[0005]

According to a first aspect of the present invention, there is provided a vehicle suspension apparatus comprising: a wheel support rotatably supporting a wheel; and a wheel support having one end connected to the vehicle body at one point and the other end provided at one point . An upper arm connected to the upper end, a lower arm connected at one end to the vehicle body and the other end connected to the lower end of the wheel support, and an upper end connected to the vehicle body and a lower end connected to an intermediate portion of the lower arm And a connecting rod having one end connected to the shock absorber main body via the first pivot means and the other end connected to the middle of the upper arm via the second pivot means. It is characterized by having.

According to a second aspect of the present invention, in the vehicle suspension device according to the first aspect, the first and second pivot means are each formed of a ball joint.

According to a third aspect of the present invention, in the vehicle suspension device according to the first aspect, a ratio of a length from one end portion to the middle portion of the lower arm with respect to a total length thereof is defined as a ratio from the one end portion to the total length of the upper arm. It is characterized in that it is set to be larger than the ratio of the length to the middle part.

According to a fourth aspect of the present invention, in the vehicle suspension device according to the third aspect, the upper arm is disposed in front of a shock absorber.

[0009]

In the vehicle suspension device according to the first aspect, an upper arm, a lower arm, a shock absorber, and a connecting rod are provided, and one end of the connecting rod is connected to the shock absorber main body via the first pivot means. And the other end is connected to the middle part of the upper arm via the second pivot means, so that the connecting part of the upper arm with the vehicle body is one, so the connecting part is reduced and the layout is improved. Excellent. Since the upper arm can be set to a certain length, camber rigidity can be secured and sufficient camber control performance can be secured. Moreover, at the time of bumping, the rising amount of the shock absorber main body, that is, the rising amount of one end of the connecting rod is set to be different from the rising amount of the other end of the connecting rod, so that the tilting of the connecting rod can be performed. High casters can be achieved.

In the vehicle suspension device according to the second aspect, the same operation as in the first aspect is obtained, and the first and second pivoting means are each formed by a ball joint. In this case, it is possible to reliably prevent over-constraint caused by the vertical swing of the connecting rod.

In the vehicle suspension device according to the third aspect, the same effect as in the first aspect is obtained, and the ratio of the length from one end to the middle of the lower arm to the total length of the lower arm is determined by the total length of the upper arm. Is set to be larger than the ratio of the length from one end to the middle part, so that the amount of rise of one end of the connecting rod at the time of bump and the amount of rise of the other end of the connecting rod are different.
High casters can be reliably achieved through the vertical swing of the connecting rod.

[0012] In the vehicle suspension device according to the fourth aspect, the same operation as in the third aspect is obtained, and the upper arm is disposed on the front side of the shock absorber. Thus, a high caster can be reliably achieved.

[0013]

As described in the above section, the following effects can be obtained. According to the vehicle suspension device of the first aspect, since the connecting portion of the upper arm with the vehicle body is one, the number of connecting portions is reduced and the layout is excellent, and the upper arm can be set to a certain length to ensure camber rigidity; Sufficient camber control performance can be ensured, and the vertical movement of the connecting rod is set by setting the rising amount of one end of the connecting rod different from the rising amount of the other end of the connecting rod during bumping. , A high caster can be achieved.

According to the vehicle suspension device of the second aspect, the same effect as that of the first aspect is obtained, and
By configuring each of the second pivot means and the second pivot means with a ball joint, it is possible to reliably prevent over-constraint caused by vertical swinging of the connecting rod during bumping.

According to the vehicle suspension device of the third aspect, the same effect as that of the first aspect is obtained, and in addition, the amount of rise of one end of the connecting rod and the amount of rise of the other end of the connecting rod at the time of bumping. Thus, a high caster can be reliably achieved through the vertical swing of the connecting rod.

According to the vehicle suspension system of the fourth aspect, the same effect as that of the third aspect can be obtained, and the upper arm is arranged on the front side of the shock absorber, so that the connecting rod can be vertically swung. High casters can be surely achieved through this.

[0017]

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present embodiment is an example in which the present invention is applied to a front suspension device of an FF type vehicle. Since the suspension device FS has a symmetrical configuration, the right front wheel 1 will be described below with reference to FIGS. The supporting structure will be described. A front side frame 4 is provided in the wheel apron 3 of the engine room 2, and a connecting bracket 5 a of the suspension cross member 5 is fixed to the front side frame 4 with bolts 6, and a top of a suspension tower 7 formed in the wheel apron 3. The mounting part 8 for connecting the shock absorber 20
Is provided. The suspension device FS includes a wheel support 10, a shock absorber 20, a coil spring 36 disposed outside the wheel support 10, an upper arm 40, an I arm 50 and a trailing link 60 as a lower arm, a stabilizer 70, and the like. I have.

The wheel support 10 has a shaft portion 11 rotatably mounted for mounting the wheel 1a,
A knuckle 12 to which a tie rod 16 of the steering device is connected, an upper pivot portion 13, and lower pivot portions 14 and 15 provided close to each other are provided. The right end of the driving shaft 9 forms a universal joint. It is connected to the shaft portion 11 through the shaft.

With respect to the shock absorber 20 and the coil spring 36, the shock absorber 20 is formed of a general hydraulic damper, and a spring receiving member 22 fixed to the shock absorber main body 21 and the upper end of the rod 23 of the shock absorber 20 are provided. A coil spring 36 is disposed between the fixed spring receiving members 24 and the rod 2
The mounting member 25 fixed to the upper end of the
Is fixed with four bolts 8a. The lower half of the shock absorber main body 21 is composed of a fork member 26 having a pair of front and rear legs 27,
The lower end 27a of the fork member 26 is pivotally connected to a middle part of the I-arm 50 at a pivotal connection part 28, and a connecting protrusion for connecting the middle part of the upper arm 40 to the outer part of the upper end of the fork member 26. A unit 30 is provided. With respect to the pivot portion 28, a shaft member having a substantially longitudinal axis in the vehicle body direction is inserted through a cylindrical portion 51 near the outer end in the middle of the I-arm 50, and a pair of legs of the fork member 26 is inserted into both ends of the shaft member. Lower end 2 of part 27
Reference numeral 7a is pivotally mounted via a rubber bush having an axis A substantially oriented in the front-rear direction of the vehicle body and having an appropriate hardness.

The upper arm 40 will be described. The upper arm 40 is disposed substantially horizontally in the vehicle width direction at the front side of the shock absorber 20, and has a ball joint bushing whose inner end 42 has an axis C substantially in the front-rear direction. (Including a shaft-shaped ball joint and a rubber bush), the upper arm 4 is pivotally attached to the pivot bracket 5f of the connection bracket 5d of the suspension cross member 5.
The outer end portion 43 of the “0” is pivotally connected to the upper pivot portion 13 by a ball joint. Further, a middle part (substantially central part in the length direction) of the upper arm 40 is connected to the connecting part 30 by a horizontal connecting rod 41 which is oriented substantially in the front-rear direction at the connecting part 29, and the front end of the connecting rod 41 is a ball. The connection rod 41 is pivotally connected to the upper arm 40 via a joint, and the rear end of the connection rod 41 is pivotally connected to the connection protrusion 30 via a ball joint.

The I arm 50 will be described.
The arm 50 is disposed substantially horizontally in the vehicle width direction, and its inner end 52 (base end) has an axis B substantially in the front-rear direction of the vehicle body.
Via a ball joint bush (including a shaft-shaped ball joint and a rubber bush) having a pivot joint bracket 5b of the suspension cross member 5, and the outer end 53 of the I-arm 50 is connected to a front lower pivot joint. It is pivotally connected to the part 14 by a ball joint. The axis A and the axis B are substantially parallel and set in the front-rear direction of the vehicle body. With respect to the trailing link 60, the trailing link 60 is formed in a curved shape so as to go inward toward the rear end side, is disposed in a state inclined with respect to the front-rear direction, and has a front end 61 (outer end). Is connected to the rear lower pivot portion 15 via a ball joint, and is connected to a connection shaft portion 62 at the rear end of the trailing link 60.
Is connected to a pivot bracket 5c at the rear of the suspension cross member 5 via a coupling portion 63 including a rubber bush having an axial center substantially in the front-rear direction, and the coupling shaft portion 62 is axially opposed to the pivot bracket 5c. They are connected in a movement-constrained manner.

As described above, the outer end of the I-arm 40 and the outer end of the trailing link 60 are connected to the wheel support 10 so as to form a double pivot. Moment center Q
Is located as shown in FIG. The stabilizer 7
Reference numeral 0 denotes a unit formed by integrally forming a pair of left and right arm portions 71 and a torsion bar portion 72 for connecting the rear ends of the arm portions 71 to each other. Is connected to the upper end of the front leg 27.

Next, the operation of the above-described vehicle suspension device will be described. First, the kingpin axis K
As shown in FIG. 5, a line L connecting the bush at the inner end of the I-arm 50 and the mount for mounting the upper end of the shock absorber 20 is connected to the ball joint and the upper arm 40 at the outer end of the I-arm 50. A line connecting the intersection point P and the instantaneous center Q is defined as a point P, where an intersection with a line M connecting the ball joint at the outer end is an instantaneous center of the outer end of the I arm 50 and the trailing link 60. Is the kingpin axis K, and the kingpin offset can be set to a small positive value as shown in the figure, so that torque steering and kickback can be improved.

FIG. 5 is a mechanical diagram showing the suspension device FS. The front wheel 1 is bumped when the front wheel 1 bumps.
At the same time, the wheel support 10 moves upward, the I-arm 50 swings upward around its inner end 52, and the upper arm 40 swings upward around its inner end 42, The rod 23 of the shock absorber 20 is retracted, and the suspension device FS is in the state shown by the dotted line, but since the length α of the upper arm 40 is shorter than the length m of the I arm 50, the outer end 43 of the upper arm 40 is Is larger than the inward movement of the outer end 53 of the I-arm 50 in the vehicle width direction, so that the camber change characteristics can be appropriately set and the camber rigidity can be secured. . However, in order to secure the camber rigidity at the time of bumps and rebound, the rubber bush of the pivot portion 28 needs to be set to an appropriate hardness that is not too hard. Furthermore,
Since the length α of the upper arm 40 is set large, camber rigidity can be secured and sufficient camber control performance can be secured, similarly to the double wishbone type suspension. Since the upper arm 40 is composed of one member, the layout is excellent without taking up space, and only one place for pivoting to the vehicle body is required. Further, since the lower end of the shock absorber main body 21 (the lower end 27a of the leg 27 of the fork member 26) is connected to the I-arm 50 through the rubber bush of the axis A substantially in the front-rear direction, the shock absorber main body is 21 does not pivot about its axis and its support stiffness is kept sufficiently high.

Here, the axis B at which the I-arm 50 is pivotally connected to the vehicle body affects the pitch center height and affects the anti-dive geometry. On the other hand, shock absorber 20
The axis of the caster affects the caster angle and affects various alignments such as a roll center height, a pitch center height, and a damper efficiency. In FIG. 5, the height of the wheel support 10 at the time of bumping is H, the length of the I arm 50 is m, and the I arm 50 is m.
Assuming that the length from the inner end portion 52 to the pivot portion 28 is n, the rising amount h of the pivot portion 28 is H × (n / m). Assuming that the length of the upper arm 40 is α and the length from the inner end 42 of the upper arm 40 to the connecting portion 29 is β, the rising amount k of the connecting portion 29 is H × (β / α). Since n / m is set to be larger than β / α, k <h. Therefore, as shown in FIG. 6, the connecting rod 41 is connected so that its rear end is higher than its front end. 41 swings, and this swinging causes the connecting portion 29 of the upper arm 40 to slightly move rearward and the upper pivoting portion 13 of the wheel support 10 to move rearward, so that the caster angle increases and the caster becomes a high caster. Driving stability can be ensured.

Next, regarding the trailing link 60,
When the trailing link 60 is not provided, the wheel support 1 is provided by the braking force acting on the tire from the road surface during braking.
0 acts on the trailing link 60
As a result, the front-rear movement of the lower end of the shock absorber main body 21 is restrained, and the shock absorber 20 does not swing in the front-rear direction. Here, since the outer ends of the I-arm 50 and the trailing link 60 are connected to the wheel support 10 as double pivots, the inclination angle of the kingpin axis K in the front view increases as described above. Therefore, the degree of freedom in setting the king pin K is increased, and it is not necessary to extremely protrude the outer ends of the I arm 50 and the trailing link 60 into the wheel support 10, so that the layout is improved.

The trailing link 60 may extend forward instead of extending rearward from the shock absorber 20. Further, as shown in FIG. 7, a fork member 26A and an upper arm 40A may be formed, and the trailing end of the trailing link 60A is connected to the vehicle body via a rubber bush having a vertical axis. Is also good. Further, as shown in FIG. 8, an A-shaped arm 50A in which the I-arm 50 and the trailing link 60 are integrated may be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a suspension device according to an embodiment of the present invention as viewed from the rear.

FIG. 2 is a plan view of the suspension device.

FIG. 3 is a side view of the suspension device as viewed in the direction of arrow 3 in FIG. 2;

FIG. 4 is a perspective view of a main part of the suspension.

FIG. 5 is an operation explanatory view of the suspension device.

FIG. 6 is an operation explanatory view of the suspension device.

FIG. 7 is a diagram corresponding to FIG. 4 of a suspension device according to a modification.

FIG. 8 is a diagram corresponding to FIG. 4 of a suspension device according to a modification.

[Explanation of symbols]

 Reference Signs List 20 Shock absorber 21 Shock absorber body 40, 40A Upper arm 41 Connecting rod 50 I arm 60, 60A Trailing link

Claims (4)

(57) [Claims] A wheel support rotatably supporting a wheel; an upper arm having one end connected to the vehicle body at one point and the other end connected to an upper end of the wheel support at one point; Is connected to the vehicle body and the other end is connected to the lower end of the wheel support; a shock absorber whose upper end is connected to the vehicle body and the lower end is connected to the middle of the lower arm; and one end is a shock absorber. The other end is connected to the main body via the first pivot means at the middle of the upper arm.
And a connecting rod connected via a pivot means of the vehicle. 2. The vehicle suspension device according to claim 1, wherein said first and second pivot means are each constituted by a ball joint. 3. The ratio of the length from one end to the middle of the lower arm with respect to the entire length of the lower arm is set to be larger than the ratio of the length from the one end to the middle with respect to the entire length of the upper arm. The vehicle suspension device according to claim 1, wherein: 4. The suspension apparatus according to claim 3, wherein the upper arm is provided on a front side of a shock absorber.