JP2915663B2 - Method of manufacturing fork member coupled to suspension damper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coupling portion coaxially coupled to one end of a suspension damper, and symmetrically extending from an outer peripheral portion of the coupling portion along an axis of the coupling portion. And a method of manufacturing a fork member coupled to a suspension damper having a pair of arm portions.

[0002]

2. Description of the Related Art As a structure of a connecting portion with a suspension arm in a suspension damper, a fork member having a pair of fork-shaped arms is integrally connected to an end of an outer cylinder of a linear sliding damper. There is something. In this fork member connection structure, a steel plate that is bent into a U-shape is welded to the end of the outer cylinder, or a slot is provided in a forged or cast product made of steel. In some cases, the slit portion is integrally connected to the outer peripheral surface of the end of the outer cylinder by tightening with a bolt.

In the above fork member, it is conceivable to form the fork member using an aluminum alloy material in order to reduce the weight. In manufacturing the aluminum fork member, it can be performed by casting or forging.

[0004] However, in the case of casting, shrinkage cavities occur due to a large change in thickness due to a plurality of thick portions, and it is necessary to increase the thickness in order to improve strength and toughness. Since the variation in strength is not small, there is a problem such as an increase in manufacturing cost due to strengthened quality control.
In addition, in the case of forging, after-forging is required for inspections and corrections between processes due to the complexity of the manufacturing process, and because of the short life of the mold, the production cost rises and casting cannot be performed in the case of casting. There is a problem such as an increase in the number of man-hours for machining.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, a main object of the present invention is to manufacture a fork member capable of further improving the quality and strength and to improve the production efficiency. An object of the present invention is to provide a method of manufacturing a fork member to be coupled to a device damper.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a coupling unit coaxially coupled to one end of a suspension damper, and the coupling unit extending along an axis of the coupling unit. A method for manufacturing a fork member having a pair of arms symmetrically extended from an outer peripheral portion thereof, comprising: a main body to be the coupling portion; and a substantially radial outward direction from the main body and from both diagonal positions. A step of extruding a fork material having an extending portion to be the arm portion to be extended by extrusion, and a fork molded body to be the fork member having a cut surface intersecting the extruding direction of the fork material in the extrusion direction. And a step of bending the extended portion of the cut fork molded body to form the arm portion. It is achieved by providing a method of manufacturing a fork member coupled to.

[0007]

In this way, the fork member connected to the suspension damper can be manufactured by extrusion molding.

[0008]

FIG. 1 is a perspective view showing a fork member connected to a damper for a suspension system of an automobile to which the present invention is applied. The fork member 1 is provided with an annular coupling portion 3 that is coupled to one end in the axial direction of an outer cylinder 2 having a bottomed cylindrical shape indicated by an imaginary line of the damper. The annular joint 3 is coaxially fitted on the surface.

The fork member 1 integrally has a pair of arms 4a and 4b symmetrically extending from the outer periphery of the annular joint 3 along the axis of the annular joint 3. Each of the arm portions 4a and 4b is bent so that each free end portion is slightly closer to the axial extension side of the annular joint portion 3. At the free ends of the arms 4a and 4b, connection holes 5a and 5b are provided, respectively, to be connected to a suspension arm (not shown).

FIG. 2 shows an aluminum alloy material in a semi-molten state extruded by an extruder (not shown).
A main body 6 to be the annular coupling portion 3 of the fork member 1 and arm portions 4a and 4 extending radially outward from the main body 6
FIG. 3 is a schematic perspective view showing a fork material 8 formed so as to have respective extending portions 7a and 7b to be b.
FIG. 4 is a view showing a side surface of the fork material 8. The fork material 8 is provided on each arm 4 of the completed fork member 1.
a · 4b is extruded and molded in the direction of arrow A shown in the figure using a mold and a die formed so as to match the contour viewed from the axial direction before performing the bending process, and is not shown after molding. It is cooled by a cooling device.

In the next step, the fork blank 8 is cut by a cutting device (not shown) with a parallel cut surface 9 at a predetermined pitch (for example, at equal intervals) along the extrusion direction. For this cutting, for example, a band saw or a water jet may be used, and a plurality of fork moldings 10 are cut out from the fork blank 8. When the fork molded body 10 is extruded, the connecting holes 5a and 5b provided at the free ends of the arms 4a and 4b are formed simultaneously with the connecting holes 3a of the annular connecting portion 3. ing.

In this manner, the fork molded body 8 is formed, and the pair of arms 4a and 4b are then moved along the axis of the annular joint 3 and substantially parallel to each other as shown in FIG. To bend. The arms 4a and 4
The intermediate portions of the arm portions 4a and 4b are bent so as to be slightly inclined with respect to the axis in order to make the both free ends slightly closer to the axial extension of the annular joint 3.

In order to connect the annular connecting portion 3 to the outer cylinder 2, as shown in FIG.
A ridge portion 11 that protrudes radially outward in the entire circumferential direction is formed, and a circumferential groove 12 that engages with the ridge portion 11 is formed in the coupling hole 3 a of the annular coupling portion 3. Have been. Then, at the time of the above connection, the circumferential groove 12 is formed in the ridge 11 by expanding the pipe by, for example, magneform processing.
By engaging with each other, a firm integration of the two is obtained, and a finished product of the damper is formed.

Since the fork member 1 is integrally connected to the outer cylinder 2 without using a slit structure as shown in the conventional example, no waste of the connecting portion is required and the number of parts can be reduced. . Furthermore, the outer cylinder 2 can also be extruded using an aluminum alloy material, and the problem of electrolytic corrosion can be solved by forming both members into aluminum alloy.

FIG. 4 is a side view of a fork blank 13 showing another embodiment when a fork molding is cut out from a fork blank. Parts similar to those of the above-described embodiment are denoted by the same reference numerals and are detailed. Description is omitted. In this embodiment, as shown in the figure, the fork molding 14 is cut out so that both arms 4a and 4b are bent in advance with respect to the annular joint 3. By doing so, it is necessary to maintain the roundness of the coupling hole 3a of the annular coupling portion 3 even after the bending of the arm portions 4a and 4b, but the bending of the arm portions 4a and 4b Influence on roundness can be suitably prevented.

[0016]

As described above, according to the present invention, a fork material is formed by extrusion, and a fork member is formed by cutting out a fork material from the fork material. The cost can be reduced because the fork member can be improved.

[Brief description of the drawings]

FIG. 1 is a simplified perspective view showing a fork member according to the present invention.

FIG. 2 is a perspective view showing a fork material and a fork molding by extrusion.

FIG. 3 is a schematic cross-sectional side view showing a connecting point of a fork member and a damper to which the present invention is applied.

FIG. 4 is a side view showing a second embodiment showing a cutting procedure of a fork material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fork member 2 Outer cylinder 3 Annular connection part 3a Connection hole 4a, 4b Arm part 5a, 5b Connection hole 6 Main body 7a, 7b Extension part 8 Fork material 9 Cutting surface 10 Fork molding 11 Protrusion part 12 Circumferential groove 13 Fork material 14 Fork molding

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-321831 (JP, A) JP-A-60-104823 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B21C 23/14 F16F 9/54

Claims (2)

(57) [Claims] A coupling portion coaxially coupled to one end of a suspension damper; and a pair of arm portions symmetrically extended from an outer peripheral portion of the coupling portion along an axis of the coupling portion. A fork material comprising: a main body to be the coupling portion; and an extension portion to be the arm portion extending substantially radially outward from the main body and from both diagonal positions. Extruding the fork material, cutting the fork material to be the fork member with a cut surface intersecting with the extrusion direction of the extrusion molding, and cutting the fork material. Forming the arm by bending the extending portion. A method for manufacturing a fork member coupled to a suspension damper. 2. The method according to claim 1, wherein when the fork molded body is extruded, the connecting portion is simultaneously molded into an annular shape that can be fitted to the outer peripheral surface of one end of the suspension damper. A method for manufacturing a fork member coupled to the suspension damper according to any one of the preceding claims.