JPH01143725A - Manufacture of cup-shaped washer for separator - Google Patents

Abstract

PURPOSE:To obtain a cup-shaped washer high in dimensional accuracy and excellent in quality by providing a separator through-hole having a folded and reinforced peripheral part and smaller in diameter than specified dimensions and finally pressing a die for remedying a hole diameter to a specified diameter into the through-hole to be finished. CONSTITUTION:In a working area for a cup-shaped washer, a cup-shaped projection 13 is pressed and a prepared hole 15 of small diameter is made by a male trimming die 17 of a lower die 16 and a female trimming die 19 of an upper die 18 at a suitable place 14 of the bottom of the projection 13. The peripheral edge part of the prepared hole 15 is burred outward by a male burring die 20 of the lower die 16 and a receiving hole part 21 of the upper die 18 to form a cylinder part 22. The cylinder part 22 is folded outward by a male die part 23 of the upper die 18 and a forming recess part 24 to make a folded part 22a. The folded part 22 and a suitable place 14 on the bottom part of the cup-shaped projection 13 are pressed by a receiver part 25 of the lower die 16 and a receiver part 26 of the upper die 18 to be brought into contact with each other and to compose a through-hole 28 having a folded double structure peripheral part 27 and relatively small in diameter. A trimming die part 29 for remedying the hole diameter of the lower die 16 is pressed into the through-hole 28a, removed and finished into a separator through-hole having specified dimensions.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a method for manufacturing a cup-shaped washer in which a formwork temporary support is fitted as a locking washer to a separator for regulating the interval between concrete formworks. It is related to.

(Prior art and its problems) As shown in Figs. 1 and 2, this type of cup-shaped washer 1
The metal plate is pressed into a cup shape and has a separator through hole 2 formed in the center of the bottom.
The distal end spiral portion 6 of the separator 3 and the above-mentioned break-off are arranged so that the peripheral edge of the separator through hole 2 is in contact with the outer enlarged diameter portion 5 of the small-diameter break-off portion 4 rolled on the separator 3 and positioned. Although it is used by fitting between the small diameter part 4 for break-off, the amount of protrusion of the outer expanded diameter part 5 formed when the small diameter part 4 for break-off is formed is small; The difference between the outer diameter and the separator shaft diameter is very small, in other words, the dimensional tolerance range of the separator through hole 2 is very small. Therefore, in order to configure the cup-shaped washer 1 so that the peripheral edge of the separator through-hole 2 comes into contact with the outer enlarged diameter portion 5 and the cup-shaped washer 1 is reliably positioned, the dimensional accuracy of the separator through-hole 2 must be made sufficiently. must be increased to

As mentioned above, in order to improve the dimensional accuracy of the separator through-holes, it would be sufficient to simply punch out the holes, but in order to reduce costs, it is required to use thin plates as much as possible. When constructing a separator through hole in a cup-shaped washer of a mold by punching as described above, the peripheral edge strength of the through hole is insufficient, and the separator through hole is damaged by the external force in the axial direction of the separator that acts on the washer during concrete pouring. The peripheral edge easily expands and deforms and moves over the outer expanded diameter portion 5, making it impossible for the support to hold the form plate in a predetermined position.

Therefore, it was considered to form a short cylindrical wall by burring the periphery of the separator through hole, but the presence of a cylindrical wall that fits into the separator shaft at least for a short time meant that the concrete wall could not be opened after the concrete wall was constructed. When the separator 3 is to be broken off using the small-diameter break-off portion 4 by bending the separator tip helical portion 6 protruding from inside the shaped washer 1, the peripheral cylindrical wall of the separator through hole 2 is inserted into the separator tip screw. This provides extremely large resistance to the bending operation of the shaft portion 6, which not only makes it extremely difficult to break off one end of the separator, but also causes the recess formed by the cup-shaped washer 1 to collapse. Become.

Therefore, it was considered that the peripheral edge of the separator through-hole 2 could be reinforced by folding back two layers, but compared to the burring process that forms a cylindrical wall as described above, If the separator is folded back to form two layers, there will be large variations in the finished dimensions of the separator through holes themselves. That is, it is difficult to precisely finish the diameter of the separator through-hole 2 within a small tolerance range as described above, and the rate of defective products is high.

(Means for Solving the Problems) The present invention proposes a method for manufacturing a cup-shaped washer that can solve the conventional problems as described above, and its feature is that a metal plate is pressed into a cup shape. At the same time, a separator through-hole with a diameter slightly smaller than the specified diameter is formed in the center of the bottom by folding back and reinforcing the peripheral edge, and finally, a hole diameter correction mold with a specified diameter is press-fitted into the separator through-hole to form a separator through-hole. The point is to finish it to the specified diameter.

(Example) An example of the present invention will be described below based on FIGS. 3 to 7. In this example, a band-shaped metal plate 10 is used,
When this strip-shaped metal plate 10 is intermittently transported in the length direction, it is subjected to processing operations in the following order at each stop.

Step (2) A substantially circular cup-shaped washer processing region 11 is formed by the punched portion 12.

Step (2) A cup-shaped protrusion 13 is pressed into the cup-shaped washer processing area 11.

Step (2) A small-diameter pilot hole 15 is bored in a portion 14 corresponding to the bottom of the cup-shaped protrusion 13 using the male cutting die part 17 of the lower die 16 and the female cutting die part 19 of the upper die 18.

Step (2) The burring male part 20 of the lower mold 16 and the hole part 21 of the upper mold 18 are used to burr the peripheral edge of the lower hole 15 outward to form a short cylindrical part 22. .

The cylindrical part 22 is folded back to the outside by the male mold part 23 of the upper mold 18 and the molding recess 24 on its periphery, and the folded part 2
It is set as 2a.

Step (2) Between the receiving portion 25 of the lower mold 16 and the receiving portion 26 of the upper mold 18, the folded portion 22a and the portion 14 corresponding to the bottom of the cup-shaped protrusion 13 are brought into pressure contact with each other. As shown in FIG. 6, a separator through hole 28a having a circumferential edge portion 27 with a folded double structure and having a diameter slightly smaller than the specified size is configured.

Step (2) The hole diameter correction handling mold part 29 of the lower mold 16 is press-fitted into the separator through-hole 28a to finish the separator through-hole 28 whose diameter has been enlarged to a specified size as shown in FIG.

Step (2) The cup-shaped protrusion 13 is punched out from the cup-shaped washer processing area 11 and taken out as a cup-shaped washer 30.

(Operations and Effects of the Invention) As described above, according to the method of the present invention, a separator through-hole having a diameter slightly smaller than a specified size is formed by folding back and reinforcing the peripheral edge, and finally a hole having a specified diameter is formed in the separator through-hole. Since the separator through-hole is finished to a specified diameter by press-fitting a correction mold, the periphery of the separator through-hole is a cup-shaped washer that is sufficiently reinforced with a folded double structure. In comparison, a high-quality cup-shaped washer with extremely high finished dimensional accuracy of the separator through-hole can be obtained.

Therefore, it is possible to obtain a cup-shaped washer that is composed of a thin plate and has no problems in terms of strength and in the work of breaking off the separator while reducing costs. It has now become possible to easily manufacture a safe, high-quality cup-shaped washer that can be reliably positioned at its diameter.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a cup-shaped washer, Fig. 2 is a vertical cross-sectional side view showing how the washer is used, Fig. 3 is a plan view showing the processing state of a band-shaped metal plate, Fig. 4 is a side view of the same, and Fig. 4 is a side view of the washer. Figure 5 is a vertical cross-sectional side view explaining the manufacturing process, Figure 6 is a vertical cross-sectional view of the main part showing the state before finishing the separator through-hole, and Figure 7 is a vertical cross-sectional view of the main part showing the state after finishing the separator through-hole. It is a diagram. 1.30...Cup-shaped washer, 2, 28a, 28...
Separator through hole, 3... separator, 4...
Small diameter part for break-off, 5... Expanded diameter part, 10... Band-shaped metal plate, 11... Cup-shaped washer processing area, 12... Punching part, 13... Cup-shaped protrusion part, 14 ... bottom equivalent part, 15 ... pilot hole, 16 ... bottom mold, 18 ...
- Upper mold, 22... cylindrical part, 22a... folded part,
27... Peripheral part of folded double structure, 29... Handling mold part for hole diameter correction.

Claims (1)

[Claims] A metal plate is press-formed into a cup shape, and a separator through hole with a diameter slightly smaller than the specified diameter is formed in the center of the bottom by folding back the periphery and reinforced, and finally, a hole diameter correction mold of the specified diameter is formed in the separator through hole. A method of manufacturing a cup-shaped washer for a separator, comprising press-fitting the separator through-hole to a specified diameter.