JPH021585B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method of manufacturing a cap pin that is attached to a cap of a fluorescent lamp in a pair of protruding positions.

<Conventional technology> The conventional method of manufacturing cap pins for fluorescent lamps includes the following steps:
As shown in FIGS. 8 and 9, a cylindrical material 1 cut to a predetermined length is subjected to an axial compressive force to bulge out in the middle of the length to form a flange 2. The first method is to neck one open end, and as shown in FIGS. 10 to 13, a compressive force in the axial direction is applied to a faithful material 3 cut to a predetermined length, and a collar is attached to the outer peripheral surface. The second method involves cutting the through hole 6 with a drill after forming the portion 4 and the detents 5, and the method shown in FIGS. 14 to 17
As shown in the figure, after press-fitting a punch into a solid material 7 cut to a predetermined length to plastically process a hole 8, an axial compressive force is applied to the material formed into a cylindrical shape, and the outer periphery is A third part that bulges out the collar part 9 in the circumferential direction on the surface.
There is a method.

<Problems to be Solved by the Invention> In the cap pin manufactured by the first method described above, it is extremely difficult to form a rotation-preventing protrusion on the bulge-molded flange 2.

In addition, the second method is to provide a rotation prevention protrusion 5 on the flange 4.
... can be formed, but since the hole 6 is cut with a drill, the drilling work is time-consuming, and since a free-cutting material must be used to improve machinability, it is inferior in ductility. Cracks are likely to occur when a wire is inserted into the hole 6 and caulked. For this reason, heat treatment is often required.

In addition, the cap pin manufactured by the third method is
Since this part is buckled and then bent to form the flange part 9, the fibrous structure of the metal is locally severely deformed, as shown in FIG. 17, and the inner part A in particular has an acute angle. It is compressed and deformed to form grooves, and it is easy to break from these parts.

<Means for Solving the Problems> The present invention was proposed in view of the above, and involves loading a solid material cut into a predetermined length into a mold and regulating the external shape of the material. A punch is press-fitted from one end in the axial direction to form a bottomed hole, and a thick part that protrudes outward on the outer peripheral surface of the material is protruded along the circumferential direction by press-fitting the punch, and then the bottomed hole is press-fitted. A punch is press-fitted inside to increase the depth of the bottomed hole, forming the material into a hollow bottomed cylinder shape, and then, with the punch inserted into the bottomed hole, the thick part is pressed in the axial direction of the material. The outer diameter of the thick portion is increased to form the flange.

<Examples> The present invention will be described below based on examples shown in the drawings.

As shown in FIG. 1, the material 11 used in the present invention is a solid wire made of a copper alloy with a thickness of about 2 mm, and is cut into a predetermined length in advance.

Note that the present invention is based on cold forging in which the material 11 is processed at room temperature in each step.

First, in the present invention, as shown in FIG. A bottomed hole 16 is formed in one end of the material 11 using an upper mold 15 having a hole with an inner diameter approximately the same as that of the hole 12a, and a punch 14 disposed in the hole. A thick portion 17 is formed. To do this, the material 11 is loaded into the hole of the lower mold 13, the upper part of the material 11 is made to protrude from the opening of the stepped hole 12, and then the upper mold 15 is lowered to remove the upper part of the material 11. Stored in the hole of the upper mold 15,
In this state, the punch 14 is further lowered to press fit into the material 11 in the axial direction from one end of the material 11. punch 1
4 is press-fitted, the periphery of the material 11 is regulated by the upper mold 15 and the lower mold 13, so the material 1
A bottomed hole 16 with a depth slightly less than half the length of the material 11 is formed in the upper part of the material 11, and a portion of the material 11 left over from this drilling is formed in the stepped hole 1 of the lower mold 13.
It flows into the large diameter portion 12b of No. 2, and a thick wall portion 17 is formed to protrude. Note that even if the volume of the thick portion 17 is approximately the same as the final volume of the flange 18, the outer diameter of the thick portion 17 is smaller than the outer diameter of the flange 18 in the lower mold 1.
Since the size of the stepped hole 12 of No. 3 is set, the grain flow lines generated by this process are formed gently, and the strength does not decrease. In addition, prior to this process, the material and deformation rate of the material 11 are taken into consideration, and
It is desirable to form a pilot hole in advance at the end of the tube.

After forming the thick part 17 along the circumferential direction on the outer peripheral surface of the material 11 as described above, as shown in FIG. 3, the material 11 is loaded into the hole 20 of the lower mold 19 and Upper mold 21 with the upper part of 11 protruding
A long punch 22 is press-fitted into the bottomed hole 16 of the material 11 to increase the depth of the hole 16, and the material 11 is formed into a hollow bottomed cylindrical shape. Note that when the depth of the hole in the material 11 is increased, the material 11 is subjected to backward extrusion processing, and its length increases, but this elongation processing is a separate process in consideration of the material and deformation rate of the material 11. It may be processed by.

Next, as shown in FIG. 4, with the material 11 loaded into the stepped hole 24 of the lower mold 23 and the upper part of the material 11 protruding, the upper mold is inserted into the bottomed hole 16 of the material 11. The punch 26 of the mold 25 is press-fitted to punch out the bottom part 11' of the material 11, and the large-diameter flange molding part 27 formed at the opening of the stepped hole 24 of the lower mold 23 and the opening of the upper mold 25 are punched. The formed flange forming portion 28 presses the thick portion 17 of the material 11 in the axial direction of the material 11. When the thick part 17 of the material 11 is pressed by the flange forming part 27 of the lower die 23 and the flange forming part 28 of the upper die 25, the thick part 17 is in a state where it has been subjected to the swaging forging process, and the outside is removed. As the diameter increases, the thickness decreases to form the flange 18 of a predetermined shape, and at the same time, the flange forming part 28 of the upper mold 25 forms an edge-shaped upper surface of the flange 18, as shown in FIG. Anti-rotation protrusions 29 are formed radially.

The fluorescent lamp cap pin manufactured in this way has a predetermined outer diameter and length, as shown in FIG.
Also, a through hole 30 for wire insertion is formed inside.
Furthermore, a flange 18 of a predetermined size is formed at a predetermined position. In addition, as shown in FIG. 7, the flange part 18 has grain flow lines that are gently curved, so this part has excellent mechanical strength and there is no risk of breaking. <Advantages of the Invention> As explained above, According to the present invention, the forge flow lines of the flange formed by forging are gently curved,
Furthermore, since no grooves are formed on the inner surface of the through hole, it has excellent strength and there is no risk of breaking.

Further, according to the present invention, there is no need to perform cutting and furthermore, there is no need to perform heat treatment in the middle of the process, so the manufacturing process can be rationalized.

[Brief explanation of drawings]

Figure 1 is a front view of the material cut to a predetermined length, Figure 2 is a sectional view with a thick wall formed, and Figure 3 is a sectional view with the bottomed hole increased in depth. , Fig. 4 is a cross-sectional view of the bottom of the bottomed hole punched out and the thick part formed into the flange, Fig. 5 is a front view of the flange, and Fig. 6 is the completed fluorescent lamp base pin. FIG. 7 is a cross-sectional view of the flange of the fluorescent lamp base pin shown in FIG. 6, FIG. 8 is a cross-sectional view of a conventional cylindrical material, and FIG. 9 is a cross-sectional view of a tube made from the material shown in FIG. 8. 10 is a front view of the material used in the conventional manufacturing method of cutting holes, FIG. 11 is a sectional view of a flange formed from the material shown in FIG. 10, Figure 12 is the first
Fig. 1 is a front view of the flange, Fig. 13 is a sectional view of a fluorescent lamp cap pin manufactured from the material shown in Fig. 10, and Fig. 14 is a conventional manufacturing method in which the flange is formed by buckling. Figure 15 is a cross-sectional view of the material shown in Figure 14 with holes made;
FIG. 16 is a sectional view of a fluorescent lamp base pin whose flange is formed by pressing the material shown in FIG. 15 in the axial direction, and FIG. 17 is a sectional view of the flange shown in FIG. 16. In the figure, 11 is the material, 12 is a stepped hole, 13 is a lower die, 14 is a punch, 15 is an upper die, 16 is a bottomed hole, 17 is a thick part, 18 is a flange, and 19 is a lower die. type,
21 is the upper mold, 22 is the punch, 23 is the lower mold, 2
4 is a stepped hole, 25 is an upper mold, 26 is a punch, 2
7 and 28 are flange molding parts, 29 are anti-rotation protrusions, 3
0 is a through hole.

Claims (1)

[Claims] 1. A solid material cut to a predetermined length is loaded into a mold and its outer shape is regulated, and a punch is press-fitted in the axial direction from one end of the material to form a bottomed hole. At the same time, by press-fitting the punch, a thick wall portion protruding outward on the outer peripheral surface of the material is protruded along the circumferential direction, and then the punch is press-fit into the bottomed hole to increase the depth of the bottomed hole. The material is formed into a hollow cylindrical shape with a bottom, and then a punch is inserted into the bottomed hole and the thick part is pressed in the axial direction of the material to increase the outer diameter of the thick part to form the flange. A method for manufacturing a cap pin for a fluorescent lamp, characterized in that the cap pin is molded.