JPS6222699B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing a semi-finished product of an eye joint (also known as an eye connector, commonly known as an eyeball, or eyeglasses) that is attached to the end of an automobile fuel pipe or oil pipe, etc., and particularly relates to a method for manufacturing a semi-finished product of an eye joint (also known as an eye connector, commonly known as an eyepiece, or eyeglasses), which is attached to the end of an automobile fuel pipe, oil pipe, etc. Without,
Since it is formed by rolling using a multi-stage cold heading die, a heading punch, etc., it can be formed quickly and reliably without wasting material, making it extremely easy to manufacture the finished product. In other words, a metal cylindrical piece is attached with a cold heading die and extruded backwards with a forging punch for perforation to form a hollow cap body, and the hollow cap body is attached to the next stage of the forging die and the forging process is performed. The head of the cap body is formed into a convex arc surface using a punch, and a tube forming pin is inserted from the open end of the hollow cap body, and a tapered surface is formed in the middle of the hollow cap body using a next heading die. A tube portion is formed continuously on the tapered surface, and the hollow cap body is attached to a final heading die, and the hollow cap body is formed into a tube having a hollow sphere portion, a small diameter portion, and a large diameter portion using a punch die and a stepped pin. This manufacturing method is characterized by forming a semi-finished product consisting of parts.

2. Description of the Related Art Eye joints as shown in FIG. 2 and FIG. 6I have been conventionally used at the ends of fuel pipes, oil pipes, etc. of automobiles. This eye joint has conventionally been manufactured by the method shown in FIG.

First, the primary manufacturer produces a so-called "solid" semi-finished fitting a made of metal such as iron or aluminum with a spherical head and a cylindrical neck, and then As shown in Figure 6A, a secondary processor fixes the semi-finished product a with the chuck b of an automatic lathe, drills the neck a' with a small diameter drill C (Figure 6B), and then drills the neck a' with a small diameter drill C (Figure 6B). Form a stepped hole with drill C' of diameter (Fig. 6 C), then change the direction of fitting a with chuck b' (Fig. 6 D), and insert bit d.
Cut one side of the spherical part a'' using a drill (Fig. 6 E), and then use a drill C'' to drill a center hole perpendicular to the extension line of the stepped hole (Fig. 6 F). , change the direction of the metal fitting a (Fig. 6G), and insert the cutting tool d.
The other side of the spherical part a'' is cut using the spherical part a'', and finally the periphery of the eye hole is cut using the boring tool d' to form the eye joint. In the figure, e is the bearing shaft. According to the conventional method, there are many steps in the secondary processing, which requires a great deal of time, effort, and skill, and of course results in a lot of wasted material, and the strength and precision of the product are low.

It is also possible to manufacture this eye joint by die-casting, but die-casting would result in a fragile product and would be of no use as an important safety part, especially for automobiles.

This invention eliminates the drawbacks of the conventional examples mentioned above at once, and also makes it possible to make a metal fitting consisting of a spherical head and a cylinder hollow without cutting it. Next, the configuration of one embodiment will be described in detail with reference to the drawings. First, a 6-station part former (fully automatic multi-stage cold heading machine) including a cutting means was used with a diameter of 20 mm.
Cut the mm iron coil material into 15.5 mm length. The cylindrical piece 1a obtained by cutting is automatically transferred and attached to the first cold heading die 2a as shown in FIG. Pressure forming is performed using a punch 4a to form a conical tapered surface on the head 1a' and to form an extremely shallow recess 5a. At this time, the diameter of the cylindrical piece 1a is 21.5 mm and the length is 13.5 mm. Next, the cylindrical piece 1a is extruded from the first die 2a by the knockout pin 3a, automatically attached to the second cold heading die 2b, and then inserted into the head 1a' by the knockout pin 3a.
are brought into contact with each other, a small-diameter forging punch 4b is pushed in, and a hole is formed by backward extrusion to form a cylindrical piece 1a into a hollow cap body 1b (FIG. 4B). At this time, the outer diameter of the hollow cap body 1b is 21.65 mm, the inner diameter is 16.5 mm, and the length is 27 mm.
mm, and the depth of the large hole 5b is 23 mm. Next, the hollow cap body 1b is automatically attached to the third heading die 2c, and the small diameter knockout pin 3b is brought into contact with the head 1a', and the large hole 5b formed in the previous step is removed.
A forging punch 4c having a hemispherical tip is pushed in to form the head 1a' of the hollow cap body 1b into a convex arc shape (FIG. 4C). At this time, the outer diameter of the hollow cap body 1b is 21.75 mm, the inner diameter is 16.4 mm, the length is 30 mm, and the depth of the large hole 5b is 27.5 mm. Thereafter, the hollow cap body 1b is reversely transferred and attached into the fourth forging die 2d, which has a knockout sleeve 6a through which the tube forming pin 7a passes and whose tip 7a' protrudes, and is attached so that the tip is a concave arc. The hollow cap body 1b is pushed in with a planar forging punch 4d to form a conical tapered surface 1b' in the middle of the hollow cap body 1b and to form a tube portion 1b'' (FIG. 4D). Cap body 1b
The length is 42mm, the outer diameter of head 1a is 21.8mm, and the inner diameter is
16.8 mm, the length of the tube portion 1b'' is 12 mm, the outer diameter is 13 mm, and the inner diameter is 10.2 mm.The hollow cap body 1b is then pushed out from the heading die 2d by the knockout sleeve 6a, and then the stepped pin 7b passes through it. The hollow cap body 1b is automatically transferred into the fifth heading die 2e in which the knockout sleeve 6a' is set, and the head 1a' and the tapered surface 1 are
b' is formed in the hollow spherical part 1, and tube holes 1' are formed in the large and small diameter parts 1B and 1B' to obtain a semi-finished product. At this time, the length of the hollow cap body 1b is 36 mm,
The outer diameter of the hollow sphere part 1 is 24 mm, the inner diameter is 19 mm, and the tube part 1
The length of the semi-finished product is 12 mm, the outer diameter is 13 mm, the diameter of the large diameter part 1B is 10.1 mm, and the diameter of the small diameter part 1B' is 8.5 mm. As in the conventional example, the eye joint shown in the second and third figures is formed by cutting with a cutting tool.

In addition, in this invention example, 1
It takes about 5 seconds per piece to produce a semi-finished product, but in reality, five types of dice are operated at the same time without playing, so each piece can be manufactured in 1 second. The time to get semi-finished products is the same. On the other hand, whereas the conventional example goes through the aforementioned multiple steps in the secondary machining, the inventive example only cuts the side surface, so the time for the secondary machining is extremely shortened in the inventive example. Of course.

In this way, the present invention can significantly reduce the number of secondary processing steps and shorten the time, while the time required for primary processing is the same as in the conventional method. Since this process is carried out, there is no waste of materials, the product can be manufactured at low cost, and it is possible to obtain a product with high strength and precision.

[Brief explanation of the drawing]

Figures 1 to 4 show examples of this invention. Figure 1 is a partially cutaway perspective view of a semi-finished product obtained by the method of this invention, Figure 2 is a perspective view of the finished product, and Figure 3 is a perspective view of the finished product. FIG. 4 is an explanatory diagram showing the manufacturing process, FIG. 5 is a side view showing a half section of the metal fitting in the manufacturing process, and FIG. 6 is an explanatory diagram of the conventional method. 1...Hollow sphere part, 1a...Cylinder piece, 1a'...Cap body head, 1b...Hollow cap body, 1b'...Tapered surface, 1b''...Pipe part, 1B...Large diameter part, 1B'...
Small diameter portion, 2b, 2c, 2d, 2e...heading die, 4b, 4c...heading punch, 7a... tube forming pin, 7b... stepped pin, 8... punch die.

Claims (1)

[Claims] 1 Attach a metal cylindrical piece to a cold heading die and extrude it backwards with a forging punch for perforation to form a hollow cap body, attach the hollow cap body to the next stage of the forging die, and press the cap with a forging punch. The body head is formed into a convex arc surface, and a tube forming pin is inserted from the open end of the hollow cap body, and a tapered surface is formed in the middle of the hollow cap body using a next heading die, and furthermore, a tapered surface is formed in the middle of the hollow cap body. Continuously form a tube part, and then attach the hollow cap body to a final heading die, and use a punch die and stepped pin to separate the hollow cap body from a hollow sphere part and a tube part having a small diameter part and a large diameter part. 1. A method for producing a semi-finished product of an eye joint, characterized by forming a semi-finished product consisting of.