JPH0858331A - Double wishbone type suspension - Google Patents

Abstract

PURPOSE: To prevent a coil spring supported on the outer circumference of a shock absorber and a side frame from interfering with each other, without bending the side frame inside, or changing the sectional form of the side frame. CONSTITUTION: In a knuckle 3 supporting a wheel Wf, the knuckle main body 3 is connected to a body through a lower arm 9, and in addition the knuckle arm 3 is connected to the body through an upper arm 5. Between the knuckle arm 3 and a body frame 25, a shock absorber 14 connecting the lower arm 9 to the body is provided. The height of the lower end of a coil spring 22 provided on the outer circumference of the shock absorber 14 is set so as to settle on the higher position than the height L of the upper face of the side frame 25, even at full rebounding when the shock absorber 14 expands at maximum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knuckle for rotatably supporting a wheel, a lower arm for vertically connecting a main body of the knuckle to a vehicle body, and a main body of the knuckle for passing between the wheel and a side frame. An upper arm that connects the upwardly extending arm part to the vehicle body so that it can move up and down, a shock absorber that connects the lower arm to the vehicle body by passing between the knuckle arm part and the side frame, and a shock absorber that fits around the outer periphery of the shock absorber Relates to a double wishbone suspension including a vehicle body and a coil spring supported in an intermediate portion of a shock absorber.

[0002]

2. Description of the Related Art Such a double wishbone type suspension has been conventionally known.

FIGS. 4 to 6 show an example of a conventional double wishbone type suspension. FIG. 4 is a rear view of the left front wheel suspension of a front-wheel drive vehicle, and FIG.
5 is a cross-sectional view taken along line 5-5 of FIG. 4, and FIG. 6 is an operation explanatory view at the time of full rebound.

Front wheel Wf consisting of wheel 1 and tire 2
The knuckle 3 for rotatably supporting is integrally provided with a main body portion 3 ₁ through which the axle 4 penetrates and an arm portion 3 ₂ standing upward from the main body portion 3 ₁ . Arm 3 ₂ is tire 2
In order to avoid interference with the vehicle body, it is curved in an arc shape toward the inside of the vehicle body, and its upper end reaches above the upper end of the tire 2.

[0005] upper end of the arm portion 3 ₂ of the knuckle 3 is connected to the vehicle body frame (not shown) by the upper arm 5 made of so-called A-type arm. That is, the base end of the upper arm 5 is pivotally supported by the pair of front and rear rubber bush joints 6 and 7 so as to be swingable up and down on the vehicle body frame, and the tip of the upper arm 5 is connected to the arm portion of the knuckle 3 via the ball joint 8. It is pivotally supported at the upper end of 3 ₂ . On the other hand, the main body 3 ₁ of the knuckle 3 is connected to the vehicle body frame by a lower arm 9 and a tension rod 10, which are so-called I-shaped arms. That, is pivotally supported to the main body portion 3 ₁ of the vehicle body frame and a knuckle 3 proximal and distal ends of the lower arm 9 via a rubber bush joint 11 and the ball joints 12 respectively, tensioning the intermediate portion of the lower arm 9 extends in the vehicle front inside It is connected to the vehicle body frame by the rod 10.

The middle part of the lower arm 9 and the wheel house 1
The shock absorber 14 that connects the upper wall of the tube 3 and the upper wall of the tube 3 extends upward from a tube 16 whose lower end is pivotally supported by the lower arm 9 via a fork 15 and a piston (not shown) slidably fitted to the tube 16. , A rod 19 whose upper end is supported by the wheel house 13 through a pair of mount rubbers 17, 18, and a bump stop whose outer end is supported by the outer periphery of the rod 19 and whose lower end can oppose the upper end of the tube 16 A rubber 20 and a cylindrical cover 21 that covers the outer circumference of the rod 19 are provided.

The coil spring 22 fitted to the outer periphery of the upper portion of the shock absorber 14 has its upper end supported by an upper spring seat 23 fixed to the wheel house 13, and
The lower spring seat 2 whose lower end is provided in the middle of the tube 16
Supported by 4.

[0008] Thus, the shock absorber 14 and the coil spring 22, through the interior space of the upper arm 5 vertically, and between the arm 3 and _second side frame 25 and the knuckle 3 connected to the wheel house 13 It is arranged so as to be sandwiched.

[0009]

[SUMMARY OF THE INVENTION Incidentally, the conventional suspension, shock absorbers 14 equipped with a coil spring 22 on the outer circumference is disposed in a narrow space between the arm portions 3 ₂ and the side frame 25 of the knuckle 3 And when the shock absorber 14 is extended (rebound)
Since the lower end of the coil spring 22 largely descends (see FIG. 6), the width of the side frame 25 in the vehicle body left-right direction is set near the shock absorber 14 in order to prevent the coil spring 22 from interfering with the side frame 25. While reducing the number, the side frame 25 is curved inward of the vehicle body (engine room side).

However, when the width of the side frame 25 is partially reduced, stiffeners 26, 2 are attached to that portion.
It is necessary to weld 7 and 28 for reinforcement, or to increase the plate thickness of the material at that portion for reinforcement, which causes a problem of weight increase. Further, when the side frame 25 is curved inward of the vehicle body, not only the volume of the engine room is compressed, but also the buckling strength of the side frame 25 against a shock from the front decreases.

The present invention has been made in view of the above circumstances, and does not partially bend the side frame or partially reduce the width of the side frame.
An object of the present invention is to provide a double wishbone type suspension capable of avoiding interference between a coil spring supported on the outer periphery of a shock absorber and a side frame.

[0012]

In order to achieve the above object, the invention described in claim 1 connects a knuckle for rotatably supporting a wheel and a main body of the knuckle to a vehicle body so as to be vertically movable. Upper arm that connects the lower arm and the arm that extends upward from the main body of the knuckle through the wheel and the side frame to the vehicle body, and the lower arm that connects between the knuckle arm and the side frame to the vehicle body In a double-wishbone type suspension including a shock absorber that is fitted to the outer periphery of the shock absorber and coil springs whose upper and lower ends are supported by the vehicle body and the middle part of the shock absorber, the coil spring It is characterized in that the vertical movement range of the lower end is set above the upper surface of the side frame.

The invention described in claim 2 is characterized in that, in addition to the structure of claim 1, the lowermost part of the coil spring is arranged inside the vehicle body rather than the outer surface of the side frame.

In addition to the structure of claim 1, the invention described in claim 3 is characterized in that the coil diameter of the coil spring is reduced from the upper side to the lower side.

[0015]

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

1 to 3 show an embodiment of the present invention. FIG. 1 is a rear view of a suspension, and FIG.
FIG. 2 is a sectional view taken along line 2 and FIG. 3 is an operation explanatory view at the time of full rebound. In addition, in the embodiment shown in FIGS.
The same members as those of the conventional suspension described in 1 are denoted by the same reference numerals.

As shown in FIG. 2, the side frame 25 of this embodiment has a smaller degree of curvature than the conventional side frame 25 (see FIG. 5), and extends in a substantially straight line along the longitudinal direction of the vehicle body. Further, as shown in FIG. 1, the cross-sectional shape of the side frame 25 of the present embodiment is substantially constant along the vehicle body front-rear direction, and substantially has a slight inclined surface 25 ₁ at the upper outer corner thereof. Has a simple rectangular cross section,
Moreover, unlike the conventional side frame 25 (see FIG. 4), the stiffeners 26, 27, 28 are not used.

The side frame 25 having the above structure is adopted.
The knuckle 3 arm part 3 ₂And side frame
The space between 25 is narrower than the conventional one,
In this embodiment, by adopting the following structure, the coil
Avoiding interference between the spring 22 and the side frame 25
Can be.

That is, the lower spring seat 24 fixed to the intermediate portion of the tube 16 of the shock absorber 14 is formed in a cup shape that expands upward, and the coil spring 22 supported on the upper surface of the lower spring seat 24 is The lower end is higher than the upper surface L ₁ of the side frame 25 in the normal state shown in FIG. 1, and is substantially equal to the upper surface L _{1 of the} side frame 25 in the full rebound shown in FIG.

As a result, even at the time of full rebound where the lower end of the coil spring 22 descends most (see FIG. 3), the lower end of the coil spring 22 does not descend above the upper surface L ₁ of the side frame 25, and thus even narrow space between the arm 3 ₂ and the side frame 25 of the knuckle 3, it is possible to avoid interference between the coil spring 22 and the side frame 25.

The lower end of the coil spring 22 is located inside the outer surface L ₂ of the side frame 25 inside the vehicle body.
Therefore, the shock absorber 14 can be arranged further inward of the vehicle body without interfering with the side frame 25, and the vehicle width can be reduced.

A so-called taper spring is used as the coil spring 22, and the coil diameter D _{L at the} lower end is smaller than the coil diameter D _{U at the} upper end. Further, the wire diameter d _{L at} the lower end of the coil spring is smaller than the wire diameter d _{U at the} upper end.

By the way, it is desirable to make the height of the hood 29 as low as possible in view of design requirements. However, if the height of the lower end of the coil spring 22 is increased under such a constraint, the coil spring 22 will be increased. However, there is a problem that the total length is shortened and a sufficient stroke cannot be secured. However, if the coil diameter and the wire diameter are changed from the upper end to the lower end of the coil spring 22 as in the present embodiment, it becomes difficult for adjacent wire rods to contact each other, and even if the total length of the coil spring 22 is shortened, a sufficient stroke is achieved. Can be secured.

Thus, even when the height of the lower end of the coil spring 22 is fully rebounded, the upper surface L of the side frame 25 is
_{Since the} height is limited to be higher than the height substantially equal to ₁ , it is not necessary to bend the side frame 25 or partially change its cross-sectional shape in order to avoid interference with the coil spring 22. It is possible to avoid an increase in weight and a decrease in rigidity of the engine and a decrease in volume of the engine room.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made.

For example, although the front wheel suspension is illustrated in the embodiment, the present invention can be applied to the rear wheel suspension. Further, the shapes of the upper arm 5 and the lower arm 9 can be changed appropriately.

[0027]

As described above, according to the invention described in claim 1, the vertical movement range of the lower end of the coil spring due to the expansion and contraction of the shock absorber is set higher than the upper surface of the side frame. Interference between the coil spring and the side frame can be prevented without bending the side frame inward of the vehicle body or partially changing its cross-sectional shape. As a result, it is possible to avoid an increase in the weight of the side frame and a decrease in rigidity, and it is possible to avoid a decrease in the volume of the engine room or the trunk room.

According to the invention described in claim 2,
Since the lowermost part of the coil spring is arranged inside the vehicle body rather than the outer surface of the side frame, the shock absorber can be brought closer to the side frame, and the vehicle width can be reduced.

According to the invention described in claim 3,
Since the coil diameter of the coil spring is reduced from the upper side to the lower side, a sufficient stroke can be secured even if the total length of the coil spring is shortened.

[Brief description of drawings]

FIG. 1 is a rear view of the suspension of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

[Fig.3] Illustration of action during full rebound

FIG. 4 is a rear view of a conventional suspension.

5 is a sectional view taken along line 5-5 of FIG.

FIG. 6 is an explanatory view of the action during a full rebound.

[Explanation of symbols]

3 Knuckle 3 ₁ Main body 3 ₂ Arm 5 Upper arm 9 Lower arm 14 Shock absorber 22 Coil spring 25 Side frame Wf Front wheel (wheel)

Claims (3)

[Claims] 1. A knuckle (3) for rotatably supporting a wheel (Wf), a lower arm (9) for connecting a main body (3 ₁ ) of the knuckle (3) to a vehicle body in a vertically movable manner, and a knuckle (3). the body portion (3 ₁₎ from the wheel (Wf) and side frame (25) through the space between the arm portions extending above the) (3 ₂₎
Upper arm (5) that connects the vehicle to the car body in a vertically movable manner
And a shock absorber (14) that connects the lower arm (9) to the vehicle body through the arm portion (3 ₂ ) of the knuckle (3) and the side frame (25), and is fitted to the outer periphery of the shock absorber (14). In a double wishbone suspension having upper and lower ends and a coil spring (22) supported in the middle of the vehicle body and the shock absorber (14), the lower end of the coil spring (22) accompanying expansion and contraction of the shock absorber (14) The vertical movement range of the side frame (2
Double wishbone type suspension characterized by being set above the upper surface of 5). 2. The double wishbone type suspension according to claim 1, wherein the lowermost part of the coil spring (22) is arranged inside the vehicle body with respect to the outer surface of the side frame (25). 3. The coil diameter of the coil spring (22) is reduced from above to below.
The described double wishbone suspension.