JPH0159059B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a connecting pin with a groove for attaching a retaining piece, which is used by standing upright on the side of a potted body when securing a long and thin plate or the like to the side of the pot. The present invention relates to a mold for forming grooves for a connecting pin with grooves for attaching a retaining piece, which can be easily manufactured and mass-produced.

Conventionally, the above-mentioned connecting pins have been used in many places, but in the manufacturing process, when forming the groove for attaching the retaining piece from one end of the connecting pin to the other end, for example, a milling tool is used. It had to be shaped by machining, slotting, etc. Therefore, the manufacturing process occupies most of the manufacturing time of the connecting pin, which has been a major obstacle in manufacturing this type of connecting pin at low cost.

On the other hand, as a method for forging a suitable groove in a screw, a method for producing a grooved bolt is proposed in Japanese Patent Application Laid-open No. 79158/1983.

This manufacturing method is a method in which the hexagonal head and the vertical groove at the tip of the bolt are manufactured in one step by forging from the bolt material, and the vertical groove is formed into a wedge-shaped convexity formed protruding into the inner hole of the die. It is designed to be pressed and molded using a mold section.

However, the vertical groove formed in this way is a groove in the axial direction of the bolt, with a notch of, for example, about 1/4 circle at the distal end, and the groove gradually becomes smaller toward the proximal end. Because of this partially cut-out groove, it can be easily formed by simply providing a wedge-shaped convex part in the inner hole of the die, but when it comes to split grooves, it is difficult to form them by forging. Since the volume increase due to the groove formation during molding is very large, it has been impossible to perform molding with a structure in which a wedge-shaped convex portion is simply provided in the inner hole of the die, as described above.

Therefore, in view of the above-mentioned points, this invention aims to shorten the manufacturing process by making it possible to easily perform press forming, even if the volume increase due to the groove formed during press forming is large, and to make it suitable for mass production. The gist of this is that it has a circular mold holding hole with a bottom, an escape hole is formed in the center of the bottom of this mold holding hole, and a hole is formed in the center of this escape hole. is a mold that is attached to a mold attachment part that has a hole for extruding material, and is a cylindrical outer shell holder with a bottom that fits into the mold holding hole and has an opening positioned on the opening side of the holding hole. a plate-shaped groove-forming punch having a wedge-shaped cross-sectional shape with an acute angle of 60° to 70° and having one side that becomes slightly thinner toward the rear; and an outer diameter that can be fitted into the outer shell holder. A cylinder having an inner diameter into which a connecting pin to be formed can be inserted, and a die in which a split groove is formed in the center of the cylinder to attach a groove forming punch such that one wedge-shaped side is arranged from one end face toward the other end. , a split groove of an appropriate length, which is arranged in the escape hole of the mold attachment part and is formed to protrude inward from the center of the bottom of the outer shell holder, and into which a plate-shaped groove forming punch can be inserted, from the tip side. A die consisting of a carved extrusion rod and a groove-forming punch is fitted into the outer shell holder so that one wedge-shaped side of the groove-forming punch faces the opening side of the holder, and the extrusion rod The reason lies in the fact that the rod is formed so that it can be inserted into the die while inserting the groove forming punch into the groove of the rod.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

That is, the reference numeral 1 shown in the figure is a cylindrical outer shell, and this outer shell 1 can be attached to a mold attachment part 2 of a forging device.

This mold attachment part 2 has a circular mold holding hole 3 with a bottom.
1, and the bottom surface of this mold holding hole 31 is the contact surface 1.
8, an escape hole 19 through which an extrusion rod 17 (described later) can be inserted is formed in the center of this contact surface 18, and a hole 24 for extruding material is formed in the center of this escape hole 19.
has been formed.

Then, a cylindrical die stopper 3 that can be fitted into the outer shell 1 is formed, and the die stopper 3 is fitted from one end of the outer shell 1 to form a bottomed cylindrical outer shell holder 4.

On the other hand, a groove forming punch 5 made of a rectangular plate is formed, and one side 8 of this groove forming punch 5 has a cross-sectional shape.
It is shaped like a wedge with an acute angle of 65 degrees.
At this time, the wedge-shaped angle of the groove forming punch 5 is 60°~
Good results were obtained at around 70°, but among these
The best pressure was obtained at an angle of 65°.

Then, a cylindrical die 6 is formed, which has an outer diameter that can be fitted into the outer shell holder 4 and an inner diameter that is large enough to fit the bar 20. Two key grooves 7 are carved in the direction of the central axis, and the die 6 has one side 8 with the groove forming punch 5 formed in a wedge shape from the center of one end surface 9 of the die 6 toward the other end 10. A groove 11 is formed so as to be installed so as to face the other end 10.

Then, insert the groove forming punch 5 into the groove 11 of the die 6 from one end surface 9 to the other end 10, and insert the wedge-shaped side 8 into the groove 11 of the die 6.
from the open end 12 of the outer shell holder 4, and from the one end surface 9 side of the die 6 to be assembled.

Moreover, the width from one wedge-shaped side 8 of the groove forming punch 5 to the opposing side is the same as the inner diameter of the die 6, and the width is the same as the inner diameter of the die 6, and the width extends backward to the part that corresponds to the inner space when the groove forming punch 5 is inserted into the die 6. The relief groove 13 is formed so that it becomes slightly thinner toward the surface. Further, two keys 14 are provided on the inner peripheral surface of the open end 12 of the outer shell holder 4 and engage with the key groove 7 of the die 6 to prevent the die 6 from rotating.

A through hole 16 having approximately the same size as the inner diameter of the die 6 is bored in the center of the die stopper 3 forming the bottom of the outer shell holder 4.
A rod material that can be inserted into the groove forming punch 5 and has a die 6 at its tip that is slightly wider and deeper than the plate thickness of the groove forming punch 5.
Extruded rod 1 with grooves 15 longer than the length of
7 in the through hole 16, and the split groove 1 of the extrusion rod 17
The mold K is formed by inserting the groove forming punch 5 into the die 6 and entering the die 6.

Therefore, when the mold K formed in this way is attached to the mold attachment part 2 of the forging device and the bar 20 is inserted from the other end 10 side of the die 6, the third
As shown in the figure, the end surface of the bar 20 is formed by the groove forming punch 5.
When it comes into contact with one side 8 formed in a wedge shape and presses it as it is, a split groove 21 is gradually formed under pressure, and a part of the bar 20 pushed away by the groove forming punch 5 is removed from the bar as shown by the arrow. It extends toward the tip 22 of 20.

Therefore, the tip 23 of the extrusion rod 17 is inserted into the die 6.
If the bar 20 is placed at the same position as the one end surface 9 of the bar 20, as shown in FIG. Since it comes into contact with the tip 23, pressing of the bar 20 is completed at that point. When the extrusion rod 17 is pressed or pressed through the extrusion hole 24, which also serves as an air vent, provided at the bottom of the escape hole 19 of the mold attachment part 2, the rod in which the groove 21 is formed, as shown in FIG. The material 20 is completed.

Moreover, in this case, if the chamfer forming part 25 is made to protrude around the entire circumference near one end surface 9 of the inner circumference of the die 6 at approximately 45 degrees,
The outer peripheral end of the bar 20 can be chamfered at the same time.

The connecting pin P formed in this way has a shaft 27 that locks the retaining piece 26 attached to the split groove 21 at right angles, and has a substantially rectangular shape with an elongated hole 28 as shown in FIG. Insert the piece 26 into the oblong hole 28 and the shaft 27.
For example, a connecting pin P is erected on the columnar body 29 to connect a plate-shaped reinforcing rod 30 or the like.

Since this invention is configured as described above, it is possible to manufacture a connecting pin with a split groove for attaching a retaining piece very easily and in a short time, and since cutting is not performed, wasted materials such as chips are wasted. Since this does not occur, it can be manufactured very efficiently and at low cost, and furthermore, even if the volume increase due to the groove forming during press forming is large, press forming can be easily performed.

That is, it has a circular mold holding hole 31 with a bottom,
A relief hole 19 is formed in the center of the bottom surface of this mold holding hole 31, and a mold K to be attached to the mold mounting part 2, which has a material extrusion hole 24 formed in the center of this relief hole 19, is used to hold the mold. This holding hole 3 is inserted into the hole 31.
A bottomed cylindrical outer shell holder 4 is arranged so that the opening is located on the opening side of the outer shell holder 4, and one side is formed so that the cross-sectional shape is wedge-shaped with an acute angle of 60° to 70° and becomes slightly thinner at the rear thereof. Plate-shaped groove forming punch 5 having 8
A cylinder having an outer diameter that can be fitted into the outer shell holder 1 and an inner diameter that allows the molded connecting pin P to be inserted, and a wedge-shaped side 8 extending from one end surface to the other end at the center of the cylinder. A die 6 is provided with a split groove 11 to which the groove forming punch 5 is attached, and a die 6 is provided with a groove 11 formed in the escape hole 19 of the mold attachment part 2 and protrudes inward from the center of the bottom of the outer shell holder 1. , and an extruded rod 17 with a groove 15 of an appropriate length carved from the tip side into which a plate-shaped groove forming punch 5 can be inserted, and the die 6 to which the groove forming punch 5 is attached is attached to an outer shell holder. 1, the groove-forming punch 5 is inserted into the holding body 1 with its wedge-shaped side 8 facing the opening side of the holding body 1, and the extrusion rod 17 is inserted into the die while inserting the groove-forming punch 5 into the groove 15 of the extrusion rod 17. 6, the groove forming punch 5 is inserted into the die 6 so that the wedge-shaped tip goes from one end surface 9 of the die 6 toward the other end 10, and from the inserted one end surface 9 side. Since the bar 20 can be fitted into the outer shell holder 4 to form the groove 21 of the connecting pin P, the connecting pin P
The manufacturing process can be shortened.

That is, the bar 20 is inserted from the other end 10 of the die 6 in the mold P formed in this way and press-formed, and after the molding is completed, the connecting pin P is extruded by the extrusion rod 17 and taken out. The split groove 21 can be formed in one step on P, and compared to conventional cutting processes, no chips are produced and the process can be performed in a very short time. Furthermore, during this operation, the connecting pin P can be taken out using the extrusion rod 17 having the above-mentioned split groove 15, so it does not get stuck in the mold.
Smooth groove forming work can be performed.

Further, one side 8 of the groove forming punch 5 is wedge-shaped.
By appropriately shaping the rear part to make it slightly thinner, the resistance when the bar 20 extends as described above can be minimized when forming the split groove 21 by the wedge-shaped side 8. , pressure forming can be carried out smoothly.

In addition, since an iron bar or the like is used as the bar material 20, the material of the mold K is die steel, tool steel, high speed tool steel, etc., which are hardened to a high degree of hardness.

As explained above, according to the present invention, the split grooves can be easily formed in one step by pressing instead of cutting, reducing the processing time and allowing anyone to perform the process. Moreover, since there is no wastage of material, it can be manufactured at low cost.The structure of the mold used for the pressing process is simple and easy to assemble, making it extremely easy to use and allowing the pressing process to be carried out smoothly. It has excellent effects such as being ideal for mass production of connecting pins.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an exploded perspective view of a mold, and FIG. 2 is an exploded perspective view of a mold.
-A arrow view, Figure 3 is a front sectional view during hammering, Figure 4 is a front sectional view when hammering is completed, Figure 5 is a front sectional view when groove formation is completed, Figure 6 is a front sectional view with no removal. FIG. 3 is a perspective view showing the state in which the connecting pin with the piece attached is in use. K...mold, P...connecting pin, 1...outer shell,
2...Mold mounting part, 3...Die stopper, 4...
... Outer shell holder, 5 ... Groove forming punch, 6 ... Die, 7 ... Keyway, 8 ... One side, 9 ... One end surface, 10 ... Other end, 11 ... Division groove, 12 ... Opening end, 13... Relief groove, 14... Key, 15...
Groove, 16... Through hole, 17... Extrusion rod, 18...
...Abutting surface, 19...Escape hole, 20...Bar material, 21
... split groove, 22... tip, 23... tip, 24...
... Extrusion hole, 25 ... Chamfer forming part, 26 ... Retaining piece, 27 ... Shaft, 28 ... Oblong hole, 29 ... Column body, 30 ... Reinforcement rod, 31 ... Mold holding hole .

Claims (1)

[Claims] 1 It has a circular mold holding hole with a bottom, an escape hole is formed in the center of the bottom of this mold holding hole, and a hole for extruding material is formed in the center of this escape hole.It is attached to a mold mounting part. The mold includes a bottomed cylindrical outer shell holder that fits into the mold holding hole and has an opening positioned on the opening side of the holding hole, and a cross-sectional shape that is pointed at an acute angle of 60° to 70°. a plate-shaped groove forming punch having one side formed in a wedge shape so as to become slightly thinner at the rear thereof;
A cylinder having an outer diameter that can be fitted into the outer shell holder and an inner diameter that allows the molded connecting pin to be inserted, and a groove formed in the center of the cylinder so that one wedge-shaped side is arranged from one end surface toward the other end. A die in which a groove is formed to attach a forming punch, and a plate-shaped groove forming punch is inserted into the die, which is arranged in the escape hole of the mold attachment part and is formed to protrude inward from the center of the bottom of the outer shell holder. The die is made of an extruded rod with a groove of an appropriate length carved from the tip end, and a groove-forming punch is attached to the die. groove forming of a connecting pin with a groove for attaching a retaining piece, characterized in that the extrusion rod is formed so as to enter the die while inserting a groove forming punch into the groove of the extrusion rod. Mold.