JPS6317012B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a plug for a drum,
The details relate to a method for manufacturing small plugs for drums by integral sheet metal drawing.

There are two types of drum plugs: large and small.
In the conventional small plug product, as shown in Fig. 6, a wrench member 2 bent into a U-shaped cross section is welded to the inside of a plug body 1 drawn into a cup shape, and a screw is attached to the outside of the plug body 1. It had been cut 4 times. However, in the conventional product, the wrench member was welded, so there were problems such as defective products due to poor welding and weak strength.

The present invention is an improvement on the conventional method, and eliminates the welding process that obstructs automation, and fully automatically draws everything from the coil material to the finished product, thereby improving product strength and productivity. The purpose of the present invention is to provide a method for manufacturing a plug that can be improved and greatly reduced in cost.

In order to achieve the above object, the present invention involves drawing a wrench hole member in the form of a rectangular depression in the center of a plate blank, and then drawing a cylindrical body part on the outer periphery of the wrench hole member. A flange is formed on the periphery of the upper plate portion where the wrench hole member is provided, and a thread is cut on the outer periphery of the body portion to obtain the final product. That is.

Next, specific examples of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a plug according to the present invention, in which a wrench hole member 12 with a rectangular plane is formed in the center of an upper plate 11 of a plug body 10 formed into a cylindrical shape, and a flange 13 is further formed on the periphery of the upper plate 11. is formed from a single blank, and then a screw 15 is cut into the body 14 of the plug body 10 to obtain a final product.

Figures 2-1 to 2-10 explain the processing steps of the present invention, in which a circular depression 12a is first formed in the center of the blank 10a, and then a circular depression 12a is formed in the center of the blank 10a. The recess 12a is transformed into elliptical recesses 12b and 12c and gradually deepened, and the final shape is formed by drawing into a recess 12d with a rectangular plane. (Second
-Figure 5).

Next, a body 14a is formed on the outside of the recess 12d by drawing (Figure 2-6), the opening of the body is edged (Figure 2-7), and then the edge is raised and ironed. Then, the opening end 14b left after the edge cutting is raised and the end face is ironed at the same time (FIG. 2-8).

Furthermore, a flange 13a is formed on the periphery of the upper plate 11 where the recess 12d that will become the wrench hole member 12 is provided (Fig. 2-9), and as a final process, the opening of the body is turned inward. The edge is bent (Fig. 2-10) to obtain a semi-finished plug 16.

The mold used in the above molding process is shown in Figures 2-1 to 2.
- After omitting up to Figure 7 and cutting off the body opening,
The molds for edge raising and ironing, flange forming, and opening edge bending are shown in Figures 3 to 5. Figure 3 shows edge raising and ironing, and Figure 4 shows flange forming. FIG. 5 illustrates a mold for edge bending.

In FIG. 3, a molding die 21 is provided on the lower surface of the upper die holder 20, and a punch 23 facing upward is provided on the lower die holder 22 correspondingly.
Further, a lifter plate 24 is provided between the molding die 21 and the lower die holder 22, and a knockout block 25 is provided at the center of the molding die 21. The material that has been edged at the open end 14b of the body 14a is then used with a punch 23 and a forming die 21 to raise the edge of the open end (to straighten the body), and then to form the final edge to the inside of the opening. It is ironed to make it easier to bend.

Next, in FIG. 4, the upper mold holder 30 is provided with a plurality of drive cams 31 that point downward and have knife-shaped tips, and a forming die 32 is provided on the lower surface of the upper mold holder. Also, the lower mold holder 3
3 is provided with a die 34 and a slider cam 35 that surrounds the die and is divided into a plurality of pieces,
The slider cam 35 has an inclined insertion hole 36 having the same shape as the tip of the drive cam 31, and is normally moved away from the die 34 in the radial direction by a spring or the like (not shown), and the drive cam 31 is lowered and inclined. When the slider cams 35 enter the insertion hole 36, the slider cams 35 gather at the center position.

Further, a lifter plate 37 is provided between the lower die holder 33 and the slider cam 35, and a forming punch 38 which also serves as a knockout block is provided at the center of the upper die holder 30.
is provided.

When the material whose body part 14a has been formed in the previous process is mounted on the die 34, the upper die holder 30
is lowered and the drive cam 31 moves to the slider cam 35.
by moving the body 14a toward the center of the die 3.
4, and then the periphery of the upper plate 11 is crushed using a forming punch 38 to form a flange 13 at that portion.

FIG. 5 shows a mold for bending the edge of the body opening, with a knockout block 41 on the lower surface of an upper die holder 40, a die 43 on the lower die holder 42, and the knockout block at the center of the die 43. A lifter 44 corresponding to 41 is provided.
The raw material supplied into the die 43 is bent with the open end facing inward as the upper die holder 40 descends, resulting in a semi-finished plug shown in FIG. 2-10.

The semi-finished product formed by the mold shown in FIG. 5 is the product shown in FIGS. 1A and 1B, and a screw 15 is cut into the body 14 to obtain the final product of the plug shown in FIG. 1C.

As explained above, the present invention eliminates the welding process that reduces strength compared to the conventional welding of the plug body and the wrench hole member, and molds the entire plug from a single blank by press working. In addition to superior product strength, the automation of all processes has the effect of increasing productivity.

[Brief explanation of the drawing]

Figures 1A, B, and C are a front view and a cross-sectional view of a plug manufactured by the method of the present invention, and Figures 1 to 1
0 to 0 are process diagrams showing the processing order of the present invention, Fig. 3 shows a mold for edge raising processing, Fig. 4 shows a mold for flange forming, and Fig. 5 shows a mold for edge bending processing. FIGS. 6A, 6B and 6C are a front view and a sectional view of a plug manufactured by a conventional method. DESCRIPTION OF SYMBOLS 10... Plug main body, 11... Top plate, 12... Wrench hole member, 13... Flange, 14... Body part, 15...
Screw, 20... Upper mold holder, 21... Molding die, 2
2... Lower die holder, 23... Punch, 30... Upper die holder, 33... Lower die holder, 34... Die, 38... Forming punch, 40... Upper die holder, 41... Knockout holder, 42... Lower die holder, 43 …dice.

Claims (1)

[Claims] 1. Draw a wrench hole member with a rectangular depression in the center of the plate blank, then form a cylindrical body on the outer periphery of the wrench hole member, and then draw the wrench hole member. A method for manufacturing a plug for a drum, characterized in that a flange is formed on the periphery of the upper plate portion on which the drum is provided, and further, a thread is cut on the outer periphery of the body portion to obtain a final product.