JPH07246818A - Method for manufacturing damper fork - Google Patents

Abstract

PURPOSE:To miniaturize and lighten a damper fork and reduce the working cost. CONSTITUTION:A damper fork 10 connecting the lower end of a damper 9 of a suspension system for a vehicle to a suspension arm is formed of a press formed main fork half body 21 and press formed auxiliary fork half body 22 integrated with each other by welding 23. A clamp part 211 and slit 213 for clamping the lower end of the damper 9 are press formed integrally on the upper end of the main fork half body 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a damper fork for connecting a lower end of a damper to a suspension arm in a vehicle suspension system.

[0002]

2. Description of the Related Art In a suspension system for a vehicle, a damper for damping the vertical movement of wheels is connected to a suspension arm through a damper fork having an upper end supported by a vehicle body frame and a lower end formed in a bifurcated shape. . When the wheel is a drive wheel driven by a drive shaft, the drive shaft and the drive shaft boot covering the outer end portion thereof may interfere with the damper fork. Therefore, the damper fork is formed into a bifurcated shape. The interference is prevented by circumventing the front and rear.

FIG. 7 is a side view of a conventional damper fork. A damper fork 01 integrally formed by casting is provided with a pair of bifurcated fork halves 02, 03. The damper fork 01 is fixed to the damper 05 by tightening the slit 04 ₁ of the clamp portion 04 with the clamp bolt 06 while the lower end of the damper 05 is fitted to the clamp portion 04 formed at the upper end of the damper fork 01.

[0004]

By the way, the conventional damper fork 01 described above has a large weight because it is made of casting, and the inner peripheral surface of the clamp portion 04 and the slit 04 which the lower end of the damper 05 fits. _{Since 1} needs to be machined, there is a problem that the processing cost increases.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method of manufacturing a damper fork, which can reduce the size and weight of the damper fork and reduce the processing cost.

[0006]

In order to achieve the above object, the present invention provides a damper for manufacturing a bifurcated damper fork that connects a suspension arm that supports a wheel so that it can move up and down and a lower end of the damper. In the method of manufacturing a fork, a main fork half body integrally having a clamp portion for clamping a lower end of a damper is press-molded, and a sub-fork half body that constitutes a damper fork is press-molded in cooperation with the main fork half body. It is characterized in that both fork halves are integrally joined by welding.

[0007]

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

1 to 6 show an embodiment of the present invention. FIG. 1 is a rear view of a suspension system for a vehicle, FIG. 2 is an enlarged view in the direction of two arrows in FIG. 1, and FIG. 3 direction arrow view, FIG. 4 is FIG.
4 direction arrow view, FIG. 5 is an A direction arrow view and BB of FIG.
6 is a sectional view taken along the line E-E, and FIG.

As shown in FIG. 1, a suspension system S for an automobile is provided with an upper arm 2 and a lower arm 3 for suspending a knuckle 1 for rotatably supporting an axle of a wheel W on a vehicle body in a vertically movable manner. The inner end of the upper arm 2 is the body frame 4
Is supported via a rubber bush joint 5 and the outer end is supported on the knuckle 1 via a ball joint 6. The lower arm 3 has an inner end supported by the vehicle body frame 4 via a rubber bush joint 7 and an outer end supported by the knuckle 1 via a ball joint 8.

The damper 9 for damping the vertical movement of the wheel W is
It is fixed to the body frame 4 at its upper end. The lower end of the damper 9 is a bifurcated damper fork 10
Are fixed by clamp bolts 11, and the lower end of this damper fork 10 is connected to the intermediate portion of the lower arm 3 via a rubber bush joint 12. A coil-shaped suspension spring 13 is provided on the outer periphery of the damper 9.

The drive shaft 14, which is connected to the axle of the wheel W via a constant velocity joint (not shown), extends through the interior space of the bifurcated damper fork 10 in the lateral direction of the vehicle body. A drive shaft boot 15 that covers the constant velocity joint is provided between the outer end of the drive shaft 14 and the knuckle 1.

As is apparent from FIG. 2, even when the lower arm 3 swings and the damper fork 10 moves up and down, the drive shaft 14 moves relative to the damper fork 10 within a range shown by a pair of chain lines, and This prevents interference between the drive shaft 14 and the damper fork 10.

Next, the structure of the damper fork 10 will be described with reference to FIGS.

The damper fork 10 is a main fork half body 2.
1 and the sub-fork half body 22 are integrated by welding 23, and both of the fork half bodies 21 and 22 are manufactured by press molding.

At the upper end of the main body 21 ₀ of the main fork half body 21, there is formed a clamp portion 21 ₁ having a circular cross section into which the lower end portion of the damper 9 fits, and one side surface of the clamp portion 21 ₁ faces inward. The slit 21 ₃ sandwiched between the bent portions 21 ₂ and 21 ₂ that are bent in the vertical direction is formed. A bent portion 21 ₄ bent outward is formed at the lower end of the main body portion 21 ₀ of the main fork half body 21, and a rubber bush interposed between the bent portion 21 ₄ and the lower arm 3 is formed. The bolt hole 21 _{5 of the} joint 12 is opened.

The main body 21 ₀ of the main fork half body 21 is formed in a substantially U-shaped cross section, and the inside (that is, the side facing the drive shaft 14) of the main fork half 21 has a closed closing surface 21 ₆ . The outside (that is, the side far from the drive shaft 14) is an open surface 21 ₇ . The open surface 21 ₇ is formed so as to extend below the slit 21 ₃ of the clamp portion 21 ₁ .

Bending portions 21 ₂ and 21 _{2 of the} clamp portion 21 _1.
Plate-shaped collars 24, 24 are welded 25, 25 to the outer surfaces of the respective. The lower ends of the collars 24, 24 are welded 25, 25 so as to contact the shoulders 21 ₈ , 21 ₈ formed on the outer surface of the main fork half body 21, thereby improving the welding strength of the collars 24, 24. Is planned. Bolt holes 24 ₁ and 24 ₁ through which the clamp bolt 11 penetrates are formed in each of the collars 24 and 24. As described above, the bent portions 21 ₂ and 21 ₂ are formed in the clamp portion 21 ₁ to increase the wall thickness, and the collars 24 and 24 are welded 25 and 25 to the surface to further increase the wall thickness. Therefore, the rigidity of the clamp bolt 11 with respect to the tightening load can be improved.

The main body portion 22 ₀ of the sub-fork half body 22 is formed in a substantially U-shaped cross section, and the inside (that is, the side facing the drive shaft 14) is a closed closing surface 22 ₁ . The outside (that is, the side far from the drive shaft 14) is an open surface 22 ₂ .

An opening 2 for improving the strength of the weld 23 with the main fork half body 21 is provided at the upper end of the sub fork half body 22.
2 ₃ is formed. Further, the lower end of the auxiliary fork halves 22 are outwardly bent bent portion 22 ₄ are formed, the rubber bush joint 12 interposed between the lower arm 3 in the bent portion 22 ₄ The bolt hole 22 ₅ is opened.

The main fork half body 21 is manufactured by punching the developed shape of the main fork half body 21 from a steel plate, and bending parts 21 ₂ ,
21 ₂ and the bent portion 21 ₄ are bent, and the clamp portion 21 ₁
The opening 21 ₉ is opened between the main body 21 ₀ and the bent portion 2
A bolt hole 21 ₅ is opened in 1 ₄ . Subsequently, the main fork half body 21 is curved until it has a U-shaped cross section, and
The clamp portion 21 ₁ is attached to the main body portion 21 through the opening 21 _9.
Laterally offset with respect to ₀ , and the main fork half 21
Clamp part 2 with circular cross section by adjusting the outer shape of
1 ₁ is formed, the open surface 21 ₇ and slit 21 ₃ they formed so as to be aligned in the same direction.

The sub-fork half body 22 is manufactured by punching the expanded shape of the sub-fork half body 22 from a steel plate, bending the bent portion 22 ₄ , and opening the bolt hole 25 ₅ and the opening 22 _3. The body 22 is curved in a U-shape in cross section to form a closed surface 22 ₁ and an open surface 22 ₂ .

As mentioned above, the main fork half 21 and
Each sub-fork half 22 is formed by pressing.
Then, the two halves 21 and 22 are integrated by welding 23 and are
Since the perfork 10 is configured, it is made of a conventional casting.
It can be made lighter than a damper fork. Only
Also, when the main fork half body 21 is press-molded, the damper 9
Clamp part 21 for clamping the lower end₁Press simultaneously
Clamp part 2 shaped and aligned in the same direction at that time
1₁Pickpocket split 21₃And body 21₀Open surface 21 ₇When
Are pressed at the same time, reducing the number of processing steps
Can contribute to the downdown.

Further, the upper end of the closing surface 21 ₆ of the main body 21 ₀ is decentered to slit 21 ₃ side with respect to the center of the clamp portion 21 _1, between the upper end and the clamp portion 21 ₁ of the closing surface 21 ₆ Since the opening 21 ₉ is formed, the clamp bolt 1
The slit 21 when tightening the slit 21 ₃ 1 ₃
The elasticity of can be improved to enable reliable clamping.

Further, since the main fork half body 21 and the sub fork half body 22 are separately press-molded, the plate thickness of the main fork half body 21 on which a relatively large load acts is increased, and a relatively small load is applied. Secondary fork half 22 on which
If the plate thickness is reduced, the weight of the damper fork 10 can be further reduced while ensuring the required strength.

As is apparent from FIG. 6, in the damper fork 10 of this embodiment, the main fork half body 21 and the sub fork half body 22 are both formed in a U-shaped cross section, and both fork halves are formed. Closure surfaces 21 ₆ , of the bodies 21, 22;
Since 22 ₁ is arranged so as to face the drive shaft 14, the closing surface 21 of both fork halves 21 and 22.
_Even if the gap between ₆ , 22 ₁ and the drive shaft 14 is sufficiently secured, the centroids O ₁ , O _{2 of} both fork halves 21, 22 are secured.
Offsets S ₁ and S ₂ between the load input line and the axis L of the damper 9, which is a load input line, are smaller than those in the conventional case shown in FIG.
As a result, the strength against buckling of the fork halves 21, 22 is improved, and the required strength can be secured even if the cross-sectional area is reduced and the weight is reduced.

Further, since the closing surfaces 21 ₆ and 22 ₁ of the fork halves 21 and 22 facing the drive shaft 14 are smooth convex curved surfaces, they are damaged even if the drive shaft boot 15 comes into contact during maintenance or the like. There is no fear.

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

[0028]

As described above, according to the present invention, since the damper fork is constructed by integrally welding the press-formed main fork half body and the sub-fork half body, the damper fork is made of cast metal. The size and weight can be reduced as compared with the case. Moreover, the weight can be further reduced by changing the plate thickness of the main fork half body and the sub fork half body as necessary. Further, when the main fork half body is press-molded, the clamp portion that clamps the lower end of the damper is integrally press-molded, so that the processing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a rear view of a suspension system for a vehicle.

FIG. 2 is an enlarged view from the direction of the arrow in FIG.

FIG. 3 is a three-direction arrow view of FIG.

FIG. 4 is a four-direction arrow view of FIG.

5 is a view in the direction of arrow A in FIG. 2 and a cross-sectional view taken along line BB-EE.

FIG. 6 is an operation explanatory diagram

FIG. 7 is an operation explanatory view of a conventional damper fork corresponding to FIG. 6.

[Explanation of symbols]

3 Lower arm (Suspension arm) 9 Damper 10 Damper fork 21 Main fork half body 21 ₁ Clamp part 22 Sub fork half body 23 Welding W Wheel

Claims (1)

[Claims] 1. A method of manufacturing a damper fork for manufacturing a bifurcated damper fork (10) for connecting a suspension arm (3) supporting a wheel (W) so as to be vertically movable and a lower end of a damper (9). At the clamp part (21) for clamping the lower end of the damper (9).
_The main fork half body (21) integrally having (1) is press-molded, and the auxiliary fork half body (2) that forms the damper fork (10) in cooperation with the main fork half body (21) is formed.
2) is press-formed and both fork halves (21, 22) are integrally joined by welding (23),
Damper fork manufacturing method.