JP2614593B2 - Eye joint manufacturing method - Google Patents

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 an eye-shaped joint, that is, a fluid supply / drainage structure having a communication hole between an eye-shaped head and a pipe projecting sideways. And a method for manufacturing a joint for use with the same.

[0002]

2. Description of the Related Art An eye-shaped joint is used at a connection point between a tank portion and a pipe for supplying and discharging a fluid such as fuel or oil in an automobile, for example. -It is as shown in FIG. As shown in FIG. 13, the head of the eye-shaped joint is placed on a screw hole 44 formed in a tank portion 43 via a sealing material 45 as shown in FIG.
The tightening bolt 46 having the shape shown in FIG.
3 is screwed into the screw hole 44. On the other hand, by connecting the pipe 48 to the connection pipe 35 protruding toward the head side, the tank section 4
3 and the pipe 48 are connected in a communicating state.

[0003] In order to manufacture the eye-shaped joint, according to the conventional general technology, 1) a method of finishing by forming after casting, and 2) a method of forming a round bar by cold forging and then cutting. And finishing. However, there is a problem that the cavities are easily formed in the mold formed by the casting of the above 1), and the subsequent cutting is difficult.
In the case of the above-mentioned 2) which is formed by cold forging from a round bar material,
The cost was high, and it was necessary to finish the work afterwards.

A method developed by cutting from a flat metal strip has been developed. In this manufacturing method, for example, a metal plate having a thickness of 15 mm, a width of 28 mm, and a length of about 4 m is cut into an outer shape having a head and a pipe portion by one piece, and an eye-shaped hole is formed in the head. Also, drill through holes in the pipe part, then cut the inner peripheral surface of the eye-shaped hole into a curved shape, deburr the through hole in the pipe part, and then cut both end faces of the head, etc. And a step portion is formed in the through hole of the pipe portion.

[0005]

However, in the above-mentioned method of manufacturing by cutting from a metal flat plate, the portion to be cut and removed is very large, and the weight ratio of the product to the material is reduced to about one third. The cost of materials is very uneconomical.
In addition, since several types of single-purpose machines, special-purpose machines, automatic machines, and the like are required for the above-mentioned cutting, the problems that the machining cost is high and the production efficiency is not so high arise separately.

In order to reduce material and processing costs, various improvements and other improvements have been made so far in this manufacturing method, but this is no longer the limit.
However, processing manufacturers are now required to further reduce costs.

An object of the present invention is to solve the problems associated with the above-described conventional method for manufacturing an eye-shaped joint.
That is, an object of the present invention is to reconsider the conventional manufacturing method, eliminate waste of materials, eliminate the need for cutting and finishing with a high-precision finish, and improve production efficiency, so that cost can be significantly reduced. Another object of the present invention is to provide a method for manufacturing an eye-shaped joint.

[0008]

According to the present invention, there is provided a method of manufacturing an eye-shaped joint having an outer diameter substantially equal to an outer diameter D of an eye-shaped joint A as a product, and a predetermined length corresponding to a height H thereof. A metal pipe a cut into a pipe is formed into an eye-shaped joint A through a three-stage pressing step and a pipe connecting step,

In the first pressing step, the raw pipe a made of metal pipe is inserted into the annular concave grooves 3 having a gap equal to the thickness of the raw pipe a.
At 4, the first fixed mold 1 and the first pressing mold 2 each having concave curved surface portions 5 and 6 at the respective back ends thereof are pressed to form convex curved surface portions 8 and 9 at each edge of the base tube a. To form a first intermediate product 7 having (see FIGS. 1 to 4),

In the second pressing step, the first intermediate product 7
A second fixed mold 10 having short cylindrical holes 12 and 13 having an inner diameter equal to the outer diameter D of the eye-shaped joint A and having truncated conical holes 14 and 15 each having a smaller diameter toward the inner end thereof. And a second pressing die 11 to form a second intermediate product 16 having tapered cross-sections 17, 18 inclined in the center line direction at the lower part and the upper part of the first intermediate product 7. (See FIGS. 5-7)

In the third pressing step, the second intermediate product 1
6, a third fixed mold 19 having a short cylindrical hole 21 having an outer diameter and a depth equal to the outer diameter D and the height H of the eye-shaped joint A;
By pressing with a third pressing mold 20 having a flat pressing surface 22, the lower part and the upper part of the second intermediate product 16 are
Disc 2 with a central hole having a plane orthogonal to the center line X
3 and 24 (see FIGS. 8 and 9),

A central hole correction rod 29 having an outer diameter equal to the inner diameter d of the inner peripheral edge 27, 28 of the eye-shaped joint A is press-fitted into each of the central holes 25, 26, and the inner peripheral end having a predetermined inner diameter is inserted. Rim 3
Forming a third intermediate product 30 having 1, 32 (see FIGS. 10 and 11);

In the pipe connecting step, the third intermediate product 30
After forming a through hole 34 in a part of the side peripheral portion 33, a connecting pipe 35 is fixed to the through hole 34 (FIG. 12).
See FIG. 14).

The upper and lower disc-shaped portions 23 and 24 of the eye-shaped joint A are finished to be flat by press working. However, in order to enhance the sealing effect when they are brought into close contact with a sealing material during use. Alternatively, a cutting process may be performed so that a concavo-convex strip forms a shallow uneven surface.

[0015]

In the method of manufacturing the eye-shaped joint A according to the present invention, the material is an outer diameter substantially equal to the outer diameter D of the eye-shaped joint A as a product, and has a predetermined length according to its height. Tube a made of short cylindrical metal pipe
(See FIG. 1). Therefore, unlike the conventional method of manufacturing an eye-shaped joint using a round bar or a flat strip, it is necessary to cut, remove, or punch out unnecessary portions. Excluding the portion that becomes the burr 36, the joint is deformed into the eye-shaped joint A without changing the volume, so that the material is not wasted and the cost is greatly reduced.

In the first pressing step of the present manufacturing method, convex curved portions 8 and 9 are formed at each end of the metal pipe a (see FIG. 4). Therefore, in the subsequent third pressing step, the upper and lower surfaces are pressed by the third fixed die 19 and the third pressing die 20 to form a disc-shaped portion 23 with a central hole having a plane perpendicular to the center line X, When the central hole correction rod 29 is press-fitted into each of the central holes 25 and 26 after the formation of the central hole 24, the central hole correction rod 29 can be smoothly pressed (FIG. 10).
And the inner peripheral edges 31 and 3 of the central holes 25 and 26, respectively.
2 can form a highly accurate inner peripheral surface along the outer peripheral surface of the correction rod 29 (see FIG. 11).

Further, in the second pressing step of the present manufacturing method,
Center line X between the lower part and the upper part of the first intermediate product 7
It is bent in the direction and formed in the tapered sections 17 and 18 inclined in the direction of the center line X (see FIGS. 6 and 7). Therefore, in the subsequent third pressing step, the disk is pressed between the third fixed die 19 and the third pressing die 20 to form the disc-shaped portions 23 and 24 with the central holes having a plane perpendicular to the center line X. In doing so, it is possible to smoothly and smoothly bend inward to form the disk-shaped portions 23, 24 with central holes orthogonal to the center line X (see FIG. 9).

As described above, the third intermediate product 3 formed through the first pressing step, the second pressing step, and the third pressing step
0 indicates that the outer diameter and height are formed to be the same as the outer diameter D and the height H of the eye-shaped joint A as a product, and the inner peripheral ends of the disc-shaped portions 23 and 24 with central holes. Rim 3
1, 32 are also the inner peripheral edges 27, 28 of the eye-shaped joint A.
It is formed with the same dimensions as the inner diameter of the high precision. Therefore, there is no need to cut and finish those portions. The inner diameter of the side peripheral portion 33 of the third intermediate product 30 is the same as the initial tube a
Therefore, it is not necessary to cut the inner peripheral portion to increase the inner diameter.

Therefore, if the connecting pipe 35 is fixed to the through hole 34 formed in the side peripheral portion in the next pipe connecting step, the third intermediate product 30 can be used as an inexpensive and highly accurate product. Shape joint A is completed.

[0020]

FIG. 12, FIG. 13 and FIG. 14 show an eye joint A manufactured by the manufacturing method according to the present invention, and FIGS. 1 to 12 show the respective steps of the manufacturing method of the eye joint according to the present invention. Is shown. In the method for manufacturing an eye-shaped joint according to the present invention, as a material, a metal pipe element which is substantially equal to the outer diameter D of the eye-shaped joint A as a product and cut to a predetermined length in accordance with the height H thereof. Use tube a.
Here, the metal pipe is, for example, an iron or stainless steel pipe (see FIG. 1).

The first stationary mold 1 and the first stationary mold 1 in the first pressing step
Each of the pressing dies 2 has annular concave grooves 3 and 4 having a gap equal to the thickness of the base tube a, and a concave curved surface portion 5 at the inner end thereof.
6. By pressing the first fixed mold 1 and the first pressing mold 2, a convex curved surface portion 8,
A first intermediate product 7 having a first intermediate product 9 is formed.
reference).

The first fixed die 1 and the first pressing die 2
It is preferable that the shape of the concave curved surface portions 5 and 6 at the innermost ends of the annular concave grooves 3 and 4 be formed in a curved surface having a radius substantially equal to the thickness of the base tube a. Note that the first fixed mold 1 is not a single unit, but forms the annular groove 3 and the concave curved surface portion 5 with an inner mold 37 slidable upward. A first intermediate product pushing rod 38 is screwed on the lower part (see FIG. 2).

Further, the depth of the annular groove 3 of the first fixed mold 1 is set to be slightly larger than the depth of the annular groove 3 of the first pressing mold 2, and after the two molds 1 and 2 are separated. The first intermediate product 7 remains. Although not shown, the upper and lower portions of the first intermediate product 7 may be slightly thinner toward the ends.

In the second pressing step, the second stationary mold 10 and the second pressing mold 11 are each provided with a short cylindrical hole 12 having an inner diameter equal to the outer diameter D of the eye-shaped joint A, and a rear end at the back. It has a truncated conical hole 14 with a smaller diameter as it gets closer. This second fixed mold 1
The second intermediate product 16 having tapered sections 17 and 18 inclined in the direction of the center line X at the lower and upper portions of the first intermediate product 7 by pressing the first intermediate product 7 with the second pressing die 11. (See FIGS. 5 to 7).

The second stationary die 10 and the second pressing die 11 used in the second pressing step are used to form the respective truncated conical holes 14, 1.
5 has a slope of 40 to 6 with respect to the center line X.
It is preferable to set the angle to about 0 degree, in other words, about 30 to 50 degrees with respect to the horizontal plane, but it is not necessarily limited to this (see FIG. 5). Also, the second fixed mold 10
Also, the second pressing die 11 is formed slightly deeper than the second pressing die 11 so that the second intermediate product 16 remains after the second pressing die 11 is detached. Reference numeral 39 denotes a second intermediate product push rod.

In the third pressing step, the third fixed mold 19 is
It has a short cylindrical hole 21 having an outer diameter and depth equal to the outer diameter D and height H of the eye-shaped joint A, and the third pressing mold 20 has a flat pressing surface 22 orthogonal to the center line X. (See FIG. 8). By pressing with the third fixed mold 19 and the third pressing mold 20, the upper and lower portions of the second intermediate product 16 inclined toward the center line are further bent, and the center line X
The disk-shaped portions 23, 24 with a central hole having a plane perpendicular to the plane are formed (see FIG. 9). The bottom surface 4 of the third fixed mold 19
0 and the pressing surface 22 below the third pressing mold 20, the center line X
The disk-shaped portions 23, 24 with a central hole are formed perpendicular to.

Further, in the third pressing step, the center holes 2 of the disk-shaped portions 23, 24 having the center holes orthogonal to the center line X are formed.
5 and 26, the outer diameter of the inner peripheral edge 2 of the eye joint A
The third intermediate product 30 having the inner peripheral edges 31 and 32 having a predetermined inner diameter is formed by press-fitting the center hole correction rod 29 equal to the inner diameter d of each of the inner and outer diameters 7 and 28. The center hole correcting rod 29 is formed at a portion near the upper part of the third intermediate product pushing rod 42 having a slightly larger diameter (see FIG. 10).

In the subsequent pipe connecting step, after a through hole 34 is formed in a part of the side peripheral portion 33 of the third intermediate product 30, a connecting pipe 35 is welded to the through hole 34 (FIG. 2). 12). FIG. 13 shows an example in which the eye joint A manufactured as described above is used. In the drawing, 43 is a tank portion, 44 is a screw hole, 45 is a sealing material, 46 is a fastening bolt, 47 is a through hole, and 48 is a pipe.

[0029]

As is clear from the above, the method for manufacturing an eye-shaped joint according to the present invention can eliminate waste of material, and can eliminate the need for cutting and finishing with a high-precision finish only by press working. Since the production efficiency can be improved, the cost can be significantly reduced.

That is, in the conventional method of manufacturing an eye-shaped joint, the method of cutting and finishing after forming by casting is such that nests are easily formed in the inside and the subsequent cutting is difficult, and the round bar is cold forged. The method of cutting and finishing after forming is costly and requires cutting.
In addition, the method of manufacturing by cutting from metal flat strips requires a lot of parts to be cut and removed, which is extremely uneconomical, and requires several types of single-purpose machines, special-purpose machines, and automatic machines for cutting. The processing cost was high.

On the other hand, in the method of manufacturing an eye-shaped joint according to the present invention, as described above, the material is an outer diameter and an inner diameter substantially equal to the eye-shaped joint, which is a product, and a predetermined value is determined according to the height of the eye-shaped joint. It uses a short cylindrical metal pipe cut into a length, and the eye-shaped joint is formed without changing the volume, so that the material is not wasted and the cost can be greatly reduced.

Further, since the convex-curved portions are formed at the respective edges of the raw tube in the first pressing step, the press-fitting of the center hole correction rod can be smoothly performed in the third pressing step. The inner peripheral edge of the central hole can be formed with high precision along the outer peripheral surface of the correction rod. In addition, since the cross-section tapered portion inclined in the center line direction is formed in the second pressing process, when forming the disc-shaped portion with the center hole in the third pressing process, it bends smoothly and inward without difficulty, A disk-shaped portion with a central hole orthogonal to the center line can be formed with high accuracy.

Except for the final pipe connection step as described above, an eye-shaped joint having a predetermined shape and dimensions can be manufactured from a short cylindrical pipe simply by a pressing step. There is no need for finishing. Therefore, the production efficiency can be improved, and the production cost can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional front view of a raw pipe as a raw material used in an embodiment of a method of manufacturing an eye-shaped joint according to the present invention.

FIG. 2 is a longitudinal sectional front view of the raw tube shown in FIG. 1 before being pressed in a first pressing step.

FIG. 3 is a vertical sectional front view at the time of pressing in a first pressing step.

FIG. 4 is a vertical sectional front view of a first intermediate product.

5 is a vertical sectional front view of the first intermediate product shown in FIG. 4 before being pressed in a second pressing step.

FIG. 6 is a vertical sectional front view at the time of pressing in a second pressing step.

FIG. 7 is a partial longitudinal front view of a second intermediate product.

8 is a vertical sectional front view of the second intermediate product shown in FIG. 7 before being pressed in a third pressing step.

FIG. 9 is a vertical sectional front view at the time of pressing in a third pressing step.

FIG. 10 is a longitudinal sectional front view when a central hole correction rod is pressed in a third pressing step.

FIG. 11 is a vertical sectional front view of a third intermediate product.

FIG. 12 is a partially cutaway front view of the eye joint.

FIG. 13 is a partially cutaway front view showing a use state of the eye joint.

FIG. 14 is a plan view of an eye joint.

[Explanation of symbols]

A-eye joint a-base tube 1-first fixed mold 2-second press mold 3-circular concave groove 4-cyclic concave groove 5-concave curved surface portion 6-concave curved surface portion 7-first intermediate product 8 -Convex curved surface portion 9-convex curved surface portion 10-second fixed mold 11-second pressing mold 12-short cylindrical hole 13-short cylindrical hole 14-frustoconical hole 15-frustoconical hole 16-first 2 Intermediate product 17-tapered section 18-tapered section 19-third fixed die 20-third pressing die 21-short cylindrical hole 22-pressing surface 23-disc part with central hole 24- Disc-shaped part with center hole 25-Center hole 26-Center hole 27-Circumference edge 28-Circumference edge 29-Central hole correction rod 30-Third intermediate product 31-Inner edge 32-Inner edge Rim 33-side peripheral part 34-through hole 35-connection pipe 36-burr 37-inner die 38-first intermediate product push rod 39-second intermediate product pusher Extension rod 40-Bottom surface 42-Third intermediate product push rod 43-Tank 44-Screw hole 45-Seal material 46-Clamp bolt 47-Through hole 48-Piping D-Outer diameter d-Inner diameter H-Height X-Center line

Claims (1)

(57) [Claims] 1. A metal pipe blank a having an outer diameter substantially equal to that of a product eye-shaped joint A and cut to a predetermined length in accordance with the height thereof, is subjected to a three-stage pressing step and a pipe connecting step. In the first pressing step, the base pipe a made of a metal pipe is formed by annular concave grooves 3 and 4 having a gap equal to the thickness of the base pipe a in the first pressing step. The first intermediate product having the convex curved surface portions 8 and 9 at each edge of the base tube a is pressed by the first fixed die 1 and the first pressing die 2 each having the concave curved surface portions 5 and 6 at the ends. In the second pressing step, the first intermediate product 7 is inserted into the short cylindrical holes 12, 1 having an inner diameter equal to the outer diameter D of the eye-shaped joint A.
3, a truncated conical hole 1 having a smaller diameter toward the far end in each deep portion thereof.
Pressed by the second fixed mold 10 and the second pressing mold 11 each having the first and fourth molds 4 and 15, the lower part and the upper part of the first intermediate product 7 are tapered in cross section inclined in the center line direction. Part 1
In the third pressing step, the second intermediate product 16 having the outer diameter D equal to the outer diameter D of the eye-shaped joint A and a short circle having a depth equal to the height H is formed. The lower part and the upper part of the second intermediate product 16 are pressed by a third fixed die 19 having a columnar hole 21 and a third pressed die 20 having a flat pressing surface 22 so that the center line is formed. It is formed in the disc-shaped portions 23, 24 having a center hole having a plane orthogonal to X, and the outer diameter of each of the center holes 25, 26 is equal to the inner diameter d of the inner peripheral edge 27, 28 of the eye joint A. An equal center hole correction rod 29 is press-fitted and inner peripheral edges 31 and 32 having a predetermined inner diameter.
In the pipe connecting step, the side peripheral portion 3 of the third intermediate product 30 is formed.
3. A method of manufacturing an eye-shaped joint, wherein a connection pipe 35 is fixed to a through hole 34 after forming the through hole 34 in a part of the third joint 3.