JP2648902B2 - Manufacturing method of cap pin - 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 for manufacturing a base pin, and has an object to prevent the inner and outer diameters of a work from being constricted and to form a crack at a joint between a flange and a work. It is another object of the present invention to provide a method of manufacturing a base pin which does not easily cause the runout of the through hole.

[0002]

2. Description of the Related Art As a conventional method for manufacturing a base pin, for example, a method described in JP-A-63-126632 "Method for manufacturing a base pin for fluorescent lamp" can be shown. In this technique, as shown in FIGS. 13 to 15, a solid material (A) cut to a predetermined length is loaded into a mold (B) and the outer shape of the material (A) is regulated. A punch (C) is press-fitted in the axial direction to form a bottomed hole (D), and a thick portion (E) protruding outward on the outer peripheral surface of the material (A) by press-fitting the punch (C). (E) is protruded along the circumferential direction (see FIG. 13), and then a punch (F) is press-fitted into the bottomed hole (D) to increase the depth of the bottomed hole (D) to increase the material (A). ) Is formed into a hollow bottomed cylindrical shape (see FIG. 14), and then, with the punch (F) inserted into the bottomed hole (D), the thick portions (E) and (E) are cut into the material (A). The flanges (G) and (G) are formed by pressing in the axial direction to increase the outer diameter of the thick portions (E) and (E) (see FIG. 15).

[0003]

However, in the method described in Japanese Patent Application Laid-Open No. 63-126632, after a thick portion protruding outward from the outer peripheral surface of the material is raised along the circumferential direction, The flange portion is formed by increasing the outer diameter of the thick portion. In other words, the material is pulled to form a thick portion in a hollow portion (bottomed hole) of the material, and then the thick portion formed by the tension is compressed to form a flange portion. Therefore, tensile and compression fatigue occurs in this material (metal material), and this flange is easily broken. Further, after forming the thick portion by pulling the material, since the thick portion formed by the tension is compressed to form a flange, the inner diameter portion of the material and the outer diameter portion of the material, Specifically, a neck is formed in the vicinity of the flange, and since the flange is formed in two steps, a crack is generated at a connection portion between the flange and the material, and the flange or the material is easily broken. Become. In addition, since the flange is formed through the second step, the number of steps for manufacturing the flange is increased, and the manufacturing efficiency is poor. Further, the tube-shaped portion on the upper part of the flange portion is formed by pressing the material once filled in the gap for forming the thick portion into the gap for forming the tube. That is, the material of the tube-shaped portion above the flange is deformed twice in the forming process, and metal fatigue is likely to occur. It seems that this problem can be solved by directly forming a flange portion instead of the thick portion described in the cited art. However, in this case, the material formed on the flange portion is reformed into the tube-shaped portion above the flange portion, and the material formed on the tube-shaped portion below the flange portion is re-formed on the flange portion. Will be forced to undergo very rapid deformation, and metal fatigue will be more likely to occur. Further, in this case, it is necessary to apply a very strong pressure to the punch, and the punch and the mold cannot withstand this pressure, and may be damaged. Therefore, this method is not practical. Further, in the drilling in the second step, since the bottomed hole is deeply drilled, a thin and long punching punch pin is used, and the center runout of the hole (the bottomed hole) is likely to occur.

In view of the above circumstances, the inventor of the present invention has found that the inner and outer diameters of the work are not constricted, no crack is formed at the connection between the flange and the work, and the run-out of the through hole is reduced. The present invention has been studied intensively on a method of manufacturing a die pin which is less likely to occur, all parts of the die are deformed only once in the manufacturing process, metal fatigue is less likely to occur, and the manufacturing process of the flange portion can be shortened.

[0005]

That is, the present invention relates to a method of manufacturing a base pin protruding from a base of a fluorescent lamp or the like, wherein a material having a hole is loaded with a material and a punch pin is provided on the material. A first step of forming a work by punching a hole having a required depth by press-fitting the upper end of the vicinity of the flange forming expected position to form a work, and forming a front end of the work in a tapered shape. After loading the work into two dies having the provided holes and disposing a punch on the flange forming portion to form a flange forming space, the two punch pins provided in the punch are moved to a position where the flange portion is to be formed. A second step in which a solid portion of the work is pulled by press-fitting to the vicinity of the lower end to form a flange on the work, and a work having the flange provided on three dies having holes is loaded and the work is pierced. With three punch pins. A third step of deep drilling, the work is loaded into a four die having a hole provided with a die spin at the bottom, and a tapered portion formed at the tip of the work is further deeply formed with four punch pins, and the die spin is performed. A fourth step of forming a hole in the bottom of the work, and a fifth step of loading the work into five dies having holes and forming a thin hole below the hole with five punch pins having a diameter smaller than the diameter of the hole. And a sixth step of loading the work into six dies having openings and penetrating holes of the work with punch pins.

[0006]

In the first step, the material is loaded into one die having holes, and one punch pin is pressed into the material to the vicinity of the upper end of the position where the flange is to be formed, thereby forming a tube-shaped portion above the flange. To form a work having a tapered tip portion. In the first step, since the tube-shaped portion has been deformed only once, metal fatigue hardly occurs in this portion. In the second step, the work is loaded into two dies having a hole provided with a flange forming portion at an upper portion, and a punch is arranged on the flange forming portion to form a flange forming space. The other punch pin is pressed into the vicinity of the lower end of the position where the flange is to be formed, whereby the solid portion of the work is pulled to form a flange on the work. In the second step, the material at the position where the flange is to be formed is moved in the circumferential direction of the work as it is and is formed on the flange. Therefore, the manufacturing process of the flange portion can be shortened, and the tensile and compression fatigue of the metal material can be reduced, and the inner diameter portion of the work, that is, the through hole formed by penetrating the work and the outer portion of the work can be reduced. No constriction occurs at the diameter. In addition, no crack is generated at the connection portion between the flange portion and the work. Further, since a deep hole is drilled in a required process (five processes), a hole having a small runout can be machined without using a thin and long punch pin.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a base pin according to the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a material used in a method of manufacturing a die pin according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a state in which perforations are provided in the material shown in FIG. 1, and FIG. FIG. 4 is a cross-sectional view showing a state in which a perforation of the work shown in FIG. 3 is further deepened, and FIG. 5 is a cross-sectional view showing a state in which a perforation of the work shown in FIG. FIG. 6 is a sectional view showing a state in which a tapered portion is formed deeper and a hole is provided in the bottom of the work, FIG. 6 is a sectional view showing a state in which a thin hole is provided in the lower part of the work shown in FIG. 5, and FIG. 8 is a cross-sectional view showing a state in which the hole of the work is made to penetrate, FIG. 8 is a cross-sectional view showing a state in which the perforation of the work is made deeper by another third step, and FIG. FIG. 10 is a cross-sectional view showing a state in which the pin is made, FIG.
Schematic diagram for explaining the manufacturing process of the base pin similarly to
FIG. 12 is a schematic diagram for explaining the manufacturing process of the base pin as in FIG.

[0008] (1) is a base material of a base pin provided to protrude from a base of a fluorescent lamp or the like. This base material (1) is solid and made of a copper alloy. This material (1) is cut into a predetermined length in advance. The present invention is based on cold forging in which the raw material (1) is processed at room temperature in each step.

First, in the present invention, this material (1) is loaded into a hole (3) provided in a die (4). The loaded material (1) has an inner diameter of a die (4), that is, a hole (3).
Is held by As shown in FIG. 10, a push pin (2) which moves up and down is arranged below the hole (3), and a lower portion of the hole (3) is formed in a tapered shape. A punch pin (5) having a tip (7) having a diameter smaller than that of the material (1) is press-fitted into the material (1) loaded in the hole (3), and a flange portion is inserted into the material (1). A work (9a) shown in FIG. 2 is formed by piercing a hole (6) having a depth up to the vicinity of the upper end (32a) of the formation expected position (32). In this step, since the lower portion of the hole (3) is formed in a tapered shape, the tip of the work (9a) is formed in a tapered shape (hereinafter, referred to as a tapered portion (26)). When the punch pin (5) is pressed into the material (1), a gap (25) is formed between the tip (7) of the punch pin (5) and the hole (3).
Is formed, and the material (1) in the gap (25) elongates (backward extrusion). The work (9a) in which the perforations (6) are perforated is extruded from the die (4) by the rise of the push pins (2).

Next, the work (9a) having the perforated hole (6) is loaded into a hole (12) provided in a die (13). The loaded work (9a) is a die (1
It is held by the inner diameter of 3), that is, the hole (12). As shown in FIG. 11, a vertically extending push pin (10) is arranged below the hole (12), and a flange forming portion (11) is provided at the upper end. The lower part of () is formed in a tapered shape. A punch (1) is placed on a die (13) provided with a flange forming portion (11).
After the arrangement of 4) to form the flange forming space (8), the punch pin (15) provided in the punch (14) is pressed into the vicinity of the lower end (32b) of the planned flange forming position (32). As a result, the solid portion (27) of the work (9a) is pulled, and as shown in FIG.
Is formed (upsetting). The work (9b) on which the flange (16) is formed is pushed out of the die (13) by the rise of the push pin (10). The punch (1)
If a required number of concave stripes (not shown) are radially provided at the lower part of 4), when the flange (16) is formed, an edge-shaped convex ridge (not shown) is formed on the flange (16). (Not shown)
Can be preferably formed.

The work (9) on which the flange (16) is formed
In FIG. 4B, a perforation (6) is further deepened by another die (not shown) and a punch pin (not shown) as shown in FIG. 4 (backward extrusion).

The work (9c) in which the perforations (6) are further perforated is loaded into a hole (18) provided in a die (17). As shown in FIG. 12, a cylindrical extrusion sleeve (19) that moves up and down is arranged below the hole (18), and a die pin (20) slidable within the extrusion sleeve (19). ) Are arranged. The tip of the work (9c) loaded in the hole (18), that is, the tapered portion (26) is formed deeper by the punch pin (24), and the work (9) is formed by the die spin (20).
A hole (21) is formed at the bottom of c). The work (9d) having the hole (21) formed at the bottom as shown in FIG. 5 is extruded from the die (17) by raising the extrusion sleeve (19).

Next, a work (9d) having a hole (21) formed at the bottom is provided on another die (not shown), and a cylindrical extrusion sleeve which moves up and down is provided. The die pin is slidable in the sleeve and is loaded into a hole. Work (9d) loaded in this hole
A hole (6) formed in at least the work (9d).
With a punch pin (not shown) having a diameter smaller than the diameter of
As shown in FIG. 6, a small perforation (22) is provided below the perforation (6).
(Backward extrusion). In this step, the lower part of the work (9d), that is, the hole (2
1) is pressed.

A small perforation (22) is provided below the perforation (6).
The work (9e) provided with is mounted on an opening provided in another die (not shown) and having the same shape as the outer shape of the work (9e). The work (9e) loaded in the opening is passed through the holes (6), the small holes (22) and the holes (21) of the work (9e) with a punch pin (not shown) (forward extrusion). A through hole (28) is formed in the work (9e), and the base pin (2) as shown in FIG.
Form 3). In this step, the work (9e) is supported by the die.

[0015] The work (9b) on which the collar (16) is formed is formed by punching the work (9b) with another die (not shown) and at least a punch pin (6) having a diameter smaller than the inner diameter of a hole (6) formed in the work (9b). As shown in FIG. 8, the work (9f) provided with the perforations (29) may be formed (backward extrusion) by drilling the perforations (6) further deeper as shown in FIG. After the perforations (29) are formed, the above-described steps are performed, that is, the taper portion (26) of the work (9f) is formed further deeply, and a hole (not shown) is formed at the bottom of the work (9f). A thin hole (22) is formed below the hole (29), and a through hole (30) is formed as shown in FIG. By forming in this manner, a base pin (31) provided with a through hole (30) having two steps as shown in FIG. 9 can be formed.

The above-mentioned punch pins (5), (1)
5), (24), etc. and dice (4), (13), (17)
And so on are arranged at equal intervals on the same axis.
In addition, the workpieces (9a) to (9a) loaded into the dies (4), (13), (17), and the like and formed into respective shapes.
e) are the respective dies (4), (13), (17)
The next station (dies (13), (1)
7) etc.).

As described above, since the upper tube-shaped portion and the flange are formed in separate steps, the tube-shaped portion is formed by a single deformation, and metal fatigue is less likely to occur. Further, the collar (16) is also subjected to the work (9)
a) The solid portion (27) is pulled to be formed on the work (9a) by pulling, so that the manufacturing process of the flange portion (16) can be shortened and the tensile and compression fatigue of the metal material can be reduced. The inner diameter of the base pin (23), that is, the through hole (28) formed by penetrating the work (9e) and the outer diameter of the work (9e) are not constricted. In addition, the work (9
a) The solid portion (27) is pulled to form the flange portion (16) on the work (9a), so that a crack is generated at the connection portion between the flange portion (16) and the work (9a). There is no. Further, since a deep hole is drilled in a required process (five processes), a hole having a small runout can be machined without using a thin and long punch pin.

[0018]

As described above, the present invention relates to a method of manufacturing a base pin protruding from a base of a fluorescent lamp or the like,
A material is loaded into a die having a hole, and a punch pin is pressed into the material to near the upper end of a position where a flange is to be formed, thereby forming a hole having a required depth to form a workpiece, and forming a tip of the workpiece. After forming the flange forming space by loading the work in two dies having a hole provided with a flange forming portion on the upper part and forming a punch on the flange forming portion, A second step of forming a flange portion in the work by pulling a solid portion of the work by press-fitting two punch pins provided in the punch to a position near a lower end of a position where the flange portion is to be formed; A third step of loading a work provided with a flange portion on the die and drilling the work further deeper by using three punch pins; and loading the work on a fourth die having a hole provided with a die spin at a lower portion. Shishi no bread A fourth step of forming a hole at the bottom of the work by die spin while forming a taper portion formed at the tip of the work further deeply with a pin, and loading the work into five dies having holes, and at least determining the diameter of the perforated hole. A fifth step of forming a thin perforation at the bottom of the perforation with five punch pins having a small diameter, and a sixth step of loading the work in a six die having an opening and penetrating the hole of the work with the punch pin. The method according to the present invention is characterized in that the method has the following effects.

In the first step, the material is loaded into one die having holes, and one punch pin is pressed into the material to the vicinity of the upper end of the position where the flange portion is to be formed, thereby forming a tube-shaped portion above the flange portion. To form a work having a tapered tip portion. In this step, since the tube-shaped portion has been deformed only once, metal fatigue does not easily occur in this portion. In the second step, the material at the position where the flange is to be formed is moved in the circumferential direction of the work as it is and is formed on the flange.
Therefore, the manufacturing process of the flange portion can be shortened, and the tensile and compression fatigue of the metal material can be reduced, and the inner diameter portion of the work, that is, the through hole formed by penetrating the work and the outer portion of the work can be reduced. No constriction occurs at the diameter. In addition, no crack is generated at the connection portion between the flange portion and the work. Further, since a deep hole is drilled in a required process (five processes), a hole having a small runout can be machined without using a thin and long punch pin.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a material used in a method of manufacturing a base pin according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where perforations are provided in the material shown in FIG. 1;

FIG. 3 is a cross-sectional view showing a state in which a collar portion is provided on the work shown in FIG. 2;

4 is a cross-sectional view showing a state in which the work shown in FIG. 3 has a deeper hole.

5 is a cross-sectional view showing a state in which a tapered portion formed at the tip of the work shown in FIG. 4 is formed deeper and a hole is provided in the bottom of the work.

6 is a cross-sectional view showing a state in which a thin perforation is provided below the perforation of the work shown in FIG. 5;

FIG. 7 is a cross-sectional view showing a state in which a hole of the work shown in FIG. 6 is penetrated.

FIG. 8 is a cross-sectional view showing a state in which a workpiece is pierced deeper by another third step.

FIG. 9 is a cross-sectional view showing a state in which a hole of the work shown in FIG. 8 is penetrated.

FIG. 10 is a schematic view for explaining a manufacturing process of the base pin.

FIG. 11 is a schematic diagram for explaining a manufacturing process of the base pin similarly to FIG. 10;

FIG. 12 is a schematic diagram for explaining a manufacturing process of the base pin as in FIG. 10;

FIG. 13 is a schematic view for explaining a manufacturing process of a conventional base pin.

FIG. 14 is a schematic view similar to FIG. 13 for explaining a conventional manufacturing process of a base pin.

FIG. 15 is a schematic view similar to FIG. 13 for explaining a conventional manufacturing process of a base pin.

[Description of Signs] 1 Material 3 Hole 4 Dice 5 Punch Pin 6 Punch 7 Tip 8 Flange Forming Space 9a Work 9b Work 9c Work 9d Work 9e Work 11 Flange Forming Part 12 Hole 13 Dice 14 Punch 15 Punch Pin 16 Flange 17 Dice 18 Hole 20 Die-spin 21 Hole 22 Thin hole 23 Cap pin 24 Punch pin 25 Gap 26 Tapered portion 27 Solid portion 29 Punch 30 Through hole 31 Cap pin 32 Planned flange formation position 32a Upper end 32b Lower end

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-126632 (JP, A) JP-A-3-8531 (JP, A) JP-A-3-90243 (JP, A) JP-A-1- 166844 (JP, A) JP-A-1-317649 (JP, A)

Claims (2)

(57) [Claims] 1. A method of manufacturing a base pin protruding from a base of a fluorescent lamp or the like, comprising loading a material into a die having a hole, and attaching a punch pin to the material at an upper end of a position where a flange portion is to be formed.
A first step of forming a work by drilling a hole of a required depth by press-fitting the work to the vicinity and forming a tip of the work in a tapered shape; and a second step having a hole provided with a flange forming portion at an upper portion. After the work is loaded on the die and a punch is arranged on the flange forming portion to form a flange forming space, two punch pins provided in the punch are pressed into the vicinity of the lower end of the planned flange forming position. a second step of pulling a solid portion of the work to form a flange portion on the work, and loading a work provided with the flange portion on three dies having holes and piercing the work with three dies. A third step of drilling deeper with a punch pin, and loading the work into four dies having a hole provided with a die spin in the lower part, and forming a taper portion formed at the tip of the work further deep with the four punch pins. Dice with A fourth step of forming a hole in the bottom of the work by means of a hole, and loading the work into five dies having holes and forming a thin hole at the bottom of the hole by means of at least five punch pins having a diameter smaller than the diameter of the hole. A method of manufacturing a die pin, comprising: five steps; and a sixth step in which the work is loaded into six dies having openings and the holes of the work are penetrated by punch pins. 2. The die according to claim 1, wherein the third step is further deepened by three punch pins having a diameter smaller than the inner diameter of the hole formed in the work in the first step. Pin manufacturing method.