JPH1085870A - Link member and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the manufacture of a link member and to strengthen a strength by pressure-feeding and pressurizing pressure fluid into the inner part of a pipe material and forming and bending a bulging part instead of the conventional forging, etc., to the link member. SOLUTION: A recessed part 1a for forming the bulging part in the pipe material 1 is formed at the one side in the intermediate part of a bulging dies 3 and further, a gentle curving recessed part 3 is formed so as to be suitable to the curving of the link member B. The bulging dies 1 are fastened by inserting the suitable length of the pipe material 2 is inserted into gap between both bulging dies 1, and pushing dies 4 are brought into contact with the thickness parts 2a at the end parts of the pipe material 2 and pressed with hydraulic cylinders, etc., and also, the pressure fluid 5 of the water, etc., is press-fed into the inner part of the pipe material 2 from the one side of pushing die 4 and pressurized. As a result, the pipe material 2 is formed as the bulging part in the intermediate part and at the same time, is made to the thicker thickness with the thickness shifting at the center part in the other side faced to the bulging part than the other part. Then, a bearing 6 is inserted into this bulging part after boring and the link member 8 is formed by welding bearings 7 at the end parts in the right and the left parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a link member which has been conventionally manufactured by forging or the like and which is manufactured by using a pipe to reduce the weight, and a method of manufacturing the same.

[0002]

2. Description of the Related Art For example, a rocker arm of an engine or a similar link member has a structure in which a rotatable bearing is provided at the center and both ends are turned up and down. Conventionally, such a link member has been manufactured by forging, but recently, in order to reduce the weight, the link member has been manufactured into a hollow shape by pressing using a steel plate.

For example, as shown in FIG. 5, two steel plates a,
b is pressed into a shape as shown in FIGS. 5 (A) and 5 (B), and is then aligned in the middle, and the mating surfaces are joined together, as shown in FIG. 5 (C). In some cases, a pipe-shaped link member c is obtained.

In this case, a link member c having the same shape as that of the forged product is obtained by machining the central convex portion d and both end portions e to form a bearing.

[0005]

However, with such a structure, the thickness of the pressing member is substantially constant, so that when the link member a functions assembling with other parts, the central convex portion d is formed. However, bending stress concentrates on the f portion on the opposite side, which causes a problem that the strength is weakened.

Conventionally, in order to cope with such a problem, it has been necessary to join a reinforcing plate g having an appropriate thickness to the above-mentioned portion f by welding or the like to reinforce it.

However, in addition to joining the two steel plates a and b shown in FIGS. 5 (A) and 5 (B), reinforcing such a plate g not only increases the cost but also increases the cost. It had to be of poor appearance.

[0008]

SUMMARY OF THE INVENTION According to the present invention, when a link member used for a rocker arm or the like of an engine is manufactured using a pipe material, the thickness of a portion to which a bending stress is applied is specially strengthened by a plate or the like. It is an object of the present invention to provide a link member which can be made thicker than other parts without performing the method. The bearing portion is formed by bulging, and a range of a required length in the axial direction on the other side opposite to the bearing portion is formed to be thicker than other portions by the same material. According to a second aspect of the present invention, a pipe material of an appropriate length is provided in an upper and lower bulge mold having a shape that bulges one side in the axial middle portion of the pipe material as in the invention according to claim 2. Pressing dies from both ends in the axial direction Using a bulge processing means that press-fits a pressurized fluid into the pipe material from one of the pressing dies to obtain a shape along the die, and bulges toward one axially intermediate side of the pipe material. When the portion is formed, the range of the required length in the axial direction on the other side opposite to the bulging portion is made thicker by the thickness approach by the pressing die.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

FIGS. 1 and 2 show a link member according to the present invention.
As shown in FIG. 5, a pipe material is formed integrally by using a bulge processing means as follows.

That is, the basil molds 1, 1 are shown in FIG. 1 as a mating surface of one mold, and as shown in a horizontal section in FIG. Pipe material 2
A concave portion 1a for forming a bulging portion is formed, and a concave portion 3 which is gently curved so as to conform to the curvature of the link member to be obtained from both end portions to the central portion is formed.

FIG. 3 shows in advance between such left and right dies 1, 1.
As shown in (B), a pipe material 2 of an appropriate length to be machined to be processed is inserted and the two dies 1 and 1 are tightened, and the pressing dies 4 and 4 are inserted from both ends of the pipe material 2 into the ends of the pipe material 2. The pressing tool 4 is pressed by a hydraulic cylinder or the like (not shown) while being brought into contact with the meat portion 2a.

As a result, as shown in FIG. 3B, the pipe member 2 has a bulged portion 2b formed at an intermediate portion in the axial direction as shown in FIG. 3B and at the same time the other side facing the bulged portion 2b. The required length range L of the central portion 2c is made thicker than the other portions. And this bulging part 2b is used as a bearing part.

As shown in FIG. 3 (D), a bearing 6 is fitted into the bulging portion 2b, and bearings 7, 7 are welded to the left and right ends to form a link member such as a rocker arm. 8 are formed.

FIG. 4A is a cross-sectional view of the link member 8 in the longitudinal direction, and FIG.
As shown the cross section of the central portion of the (A), the thickness of the central portion 2c as t, if the thickness of both end portions (the original thickness of the pipe 2) as a t _0, the preferred range is 1. 1 × t ₀ <t
<2.5t ₀ is appropriate.

As described above, according to the present invention, the bulging portion 2b is formed and the opposing portion 2c is formed with a thick wall at the same time as the bulging portion 2b, so that the structure can sufficiently withstand the load applied to the link member 8.

[0017]

As described above, according to the present invention, it is possible to eliminate insufficient strength against bending force or the like that occurs when a pipe material is used in place of a conventionally used forging or the like. As a result, the production becomes extremely easy and the applicable range is widened. Accordingly, the present invention can be applied to, for example, a lower arm of an automobile suspension.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a method for manufacturing a link member according to the present invention.

FIG. 2 is a sectional view taken on line AA of FIG. 1;

3A and 3B show a form of a manufacturing process of a link member using a pipe member, wherein FIG. 3A shows a state of a pipe material before processing, FIG. 3B shows a state after bending, and FIG.
(D) is each front view which shows the completion state which attached the bearing to (C).

FIGS. 4A and 4B show a cross-sectional shape of FIG. 3D, wherein FIG. 4A is a cross-sectional view in a longitudinal direction, and FIG.

FIG. 5 shows one manufacturing process of a conventional link member, and FIG.
Is one piece of the link member, (B) is another piece of the link member,
(C) is each perspective view of the link member obtained by superposing (A) and (B).

[Explanation of symbols]

 Reference Signs List 1, 1 bulge type 2 pipe material 2b bulging portion 2c central portion 3 concave portion 4 pressing die 6, 7 bearing 8 link member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F16C 7/02 F16C 7/02

Claims (2)

[Claims] An axially intermediate portion of a pipe member having an appropriate length has a bearing portion formed by bulging, and a required axial length range of the other side opposite to the bearing portion is the same. A link member characterized by being formed thicker than other parts by a material. 2. A pipe material of an appropriate length is provided in a pair of bulge molds having a shape that bulges one side of an intermediate portion in the axial direction of the pipe material, and a press die is press-fitted from both axial ends of the pipe material. Using a bulge processing means that press-fits a pressurized fluid into the pipe material from one of the pressing dies so that a shape along the die can be obtained; A method of manufacturing a link member, comprising: forming a thicker portion of the required length in the axial direction on the other side opposite to the bulging portion by forming the ribs by the pressing die.