JPH0671355A - Punching method - Google Patents

Abstract

PURPOSE:To obtain a press method by which a bridging part is formed with high accuracy even in the case where the width of the bridging part to be provided between plural punched holes is comparatively small. CONSTITUTION:After providing preliminary holes 11 on the end of a shearing part in advance as a preliminary process, by each shearing a part of each peripheral part of the plural punched holes 12 by means of a first die, the bridging part 3 is formed; simultaneously, the remainder of each peripheral part of the punched holes 12 is retained in a state each connecting to a hoop metal sheet 1; then as a punching process, by shearing the remainder of each peripheral part of the punched holes 12 by means of a second die, the punched holes are formed; and the resulting scrap is removed from the hoop metal sheet 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press punching method for punching a plurality of punching holes facing each other from a hoop metal plate through a bridge portion.

[0002]

2. Description of the Related Art FIG. 4 is a plan view showing an example of a hoop metal plate having a plurality of holes. The hoop metal plate 1 shown in FIG.
Is formed in the longitudinal direction, and a plurality of holes 4a to 4e facing each other through the bridge portion 3 are formed. After forming the holes 4a to 4e in the hoop metal plate 1, outmolding is performed using the bridging portion 3 in the next step, and then the bridging portion 3 is removed from the hoop metal plate 1 by It is designed to be separated.

FIG. 5 is a cross-sectional view of a die used in the press punching method for forming the vent hole of the hoop metal plate of FIG. 4, and the hoop metal plate is made by the movable die 5 and the fixed die 6 shown in FIG. The punching holes 4a to 4e are punched out from 1. The movable mold 5 has a punch plate (not shown) that moves up and down, and a punch 7 that is planted in the punch plate and hangs down. The punch 7 is the punched holes 4a-4.
The groove portion 7a is formed in a shape corresponding to e and corresponds to the bridging portion 3. Further, the fixed mold 6 has a die 9 having a plurality of through holes 8 corresponding to the punch 7 shape.
The wall-shaped portion 10 provided between the through holes 8 can be fitted into the groove portion 7a. Since the so-called "flanking surface" is formed on the side portion of the wall-shaped portion 10 in order to smoothly drop the scrap 1a generated from the hoop metal plate 1, as compared with the width W1 of the upper surface of the wall-shaped portion 10. The width W2 of the lower portion is set to be smaller than the predetermined height position.

In the press punching method using such a die, when the punch 7 of the movable die 5 descends, the peripheral edges of the punching holes 4a to 4e are sheared over the entire circumference between the punch 7 and the die 9. It At this time, since the wall-shaped portion 10 of the die 9 is fitted into the groove portion 7a of the punch 7, the bridging portion 3 is formed. Further, the scrap 1a generated by forming the punched holes 4a to 4e drops in the through hole 8 of the die 9.

However, in the die used for such a punching method, when the width of the bridging portion 3 is relatively small, the width W2 of the lower portion of the wall-shaped portion 10 becomes further smaller, so that the punch 7 is used. When the wall-shaped portion 10 of the die 9 is fitted into the groove portion 7a of the die 9 to form the bridging portion 3, the wall-shaped portion 1 is formed by a downward force applied to the wall-shaped portion 10.
There is a concern that 0 will buckle, that is, the wall-shaped portion 10 has insufficient strength.

Therefore, as one means for solving the above problems, when the width of the bridging portion 3 is small, a plurality of punching holes 4a to 4e are punched out from the hoop metal plate 1 in the same process, and a plurality of punching holes 4a to 4e are punched. The press punching method of sequentially forming the punching holes 4a to 4e in the process has been used. In this conventional press punching method, first, after the preparation step, for example, the punching holes 4a and 4c are punched by the first die in the first step, and the hoop metal plate 1 is fed by a predetermined amount in the second step, and the first step is performed. The punching hole 4b is punched by the die 2 and the hoop metal plate 1 is further fed by a predetermined amount in the third step, and the punching hole 4d is punched by the third die, and the hoop metal plate 1 is located in the fourth step. A fixed amount is further sent, and a punching hole 4e is formed by the fourth mold.
It was supposed to punch out. In such a press punching method, since the punching holes 4a, 4b, etc. facing each other through the bridging portion 3 are not punched in the same step, the wall of the die corresponding to the bridging portion 3 corresponding to the bridging portion 3 is formed. Need not be provided,
Therefore, the strength of the die can be improved.

[0007]

By the way, in the above-mentioned conventional press punching method, since the punching holes 4a to 4e are sequentially drilled while feeding the hoop metal plate 1 in a plurality of steps, the positions of the punching holes 4a to 4e are displaced. Is likely to occur, and after forming a part of the holes, when forming another hole in the next step,
Since the hoop metal plate 1 partially moves to the other hole side and the bridge portion 3 is displaced, there is a problem that the dimensional accuracy of the bridge portion 3 is poor.

The present invention has been made in view of the actual situation in the prior art as described above, and an object thereof is to provide a bridging portion even if the width of a bridging portion interposed between a plurality of holes is relatively small. It is an object of the present invention to provide a press removing method capable of forming a portion with high accuracy.

[0009]

In order to achieve this object, the present invention provides a press punching method for punching a plurality of punching holes facing each other from a hoop metal plate through a bridge portion.
While forming the bridging portion by shearing a part of each peripheral edge of the hole in the step of, while maintaining the remaining portion of each peripheral edge of the hole is connected to the hoop metal plate, Then, in the second step, the remaining portion of each peripheral edge of the hole is sheared to form the hole.

[0010]

According to the present invention, as described above, the bridging portion is formed by shearing a part of each peripheral edge of the hole in the first step, that is, the bridging portion is formed by the same mold. Therefore, the dimensional accuracy of the bridge portion can be improved. Further, at this time, since the remaining portions of the respective peripheral edges of the punched holes are held in a state of being respectively connected to the hoop metal plate, it is not necessary to provide a through hole for scrap removal in the die of the mold in this step. As a result, the height dimension of the wall-shaped portion corresponding to the bridging portion can be set small, and it is not necessary to provide a “flank surface” for scrap removal on the side surface of the wall-shaped portion. The strength of can be increased.

In the subsequent step, the die hole is formed by shearing the remaining portion of each peripheral edge of the die hole with another die. The die provided in this die has Since it is not necessary to provide a wall-shaped part corresponding to the bridging part, the die of the mold also has sufficient strength.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a hoop metal plate for explaining an embodiment of the press punching method of the present invention, and FIG. 2 is a sectional view of a die used in the press punching method described in FIG. In addition, in FIGS. 1 and 2, the same components as those shown in FIGS. 4 and 5 described above are denoted by the same reference numerals. That is, 1 is a hoop metal plate, 2 is a feed hole, and 3 is a bridge portion.

The pressing method according to the present embodiment includes a preliminary step of forming a plurality of relatively small preliminary holes 11 in the hoop metal plate 1 and a central portion of FIG. 1, as described in the left side portion of FIG. As described, a cutting step of shearing a part of each peripheral edge of the punched hole 12 and a cutting step of shearing a remaining part of each peripheral edge of the punched hole 12 as described in the right side portion of FIG. Contains. In the cutting step, the first mold 13 shown in FIG. 2 is used, and the first mold 13 has a punch 14 and a die 15. The punch 14 has a groove portion 14a corresponding to the bridge portion 3 and a step portion 14b formed at an end portion of the lower surface. The die 15 has a plurality of recesses 15a corresponding to the holes 12, and a wall-shaped portion 15b interposed between the recesses 15a and fitted in the groove 14a.

In this embodiment, the preliminary hole 11 is formed as the preliminary step, the hoop metal plate 1 is fed by a predetermined amount, and then the cutting step is performed by the first die 13 as the cutting step 12. A part of each peripheral edge is sheared. At this time, as shown in FIG. 2, since the lower portion of the punch 14 descends into the recess 15a of the die 15, the wall portion 15b is fitted into the groove portion 14a, so that the bridge portion 3 is formed.
The lower part of the punch 14 pushes down a part of the hoop metal plate 1 into the recess 15a, and the hoop metal plate 1 is bent at the edge of the recess 15a. As a result, the remaining portion of each peripheral edge of the hole 12 in the hoop metal plate 1 is held in a state of being connected to the hoop metal plate 1, respectively. Then, after feeding the hoop metal plate 1 again by a predetermined amount,
In the removal step, the removal holes 12 are formed by shearing the remaining part of each peripheral edge of the removal holes 12 with a second mold (not shown), and scraps that accompany this are removed from the hoop metal plate 1. It is like this.

In the embodiment thus constructed, the bridging portion 3 is formed by the first die 13 in the cutting step, so that the dimensional accuracy of the bridging portion 3 can be improved.
In this cutting step, the punch 14 of the first mold 13 can be reduced in the amount of entering the die 15, so that the punch 1
It is possible to improve the life of each cutting blade of the die 4 and the die 15. Further, in the cutting step, the remaining portions of the peripheral edges of the punched holes 12 are held in a state of being connected to the hoop metal plate 1, respectively. Therefore, in the cutting step, the die 15 of the first die 13 is penetrated for scrap removal. It is not necessary to provide a hole, whereby the height dimension of the wall-shaped portion 15b of the die 15 corresponding to the bridging portion 3 can be set small.
In addition, it is not necessary to provide a "flank surface" for scrap removal on the side surface of the wall-shaped portion 15b, and the strength of the die 15 can be increased. Further, in the subsequent drawing step, scrap corresponding to the hole 12 is generated by the second mold, but it is necessary to provide a wall-shaped part corresponding to the bridging part 3 in the second mold. Therefore, the die of the second mold has sufficient strength. Further, in this embodiment, since the preliminary hole 11 is provided in advance at the end of the portion to be sheared in the cutting step, the shearing in the cutting step can be easily performed.

In this embodiment, since a part of the hoop metal plate 1 is housed in the recess 15a in the cutting step, the floating mechanism or the knockout mechanism is provided in the first mold 13. The transition from the cutting step to the next cutting step can be performed more smoothly.
Furthermore, in this embodiment, a part of the hoop metal plate 1 is pushed down, but a part of the hoop metal plate 1 can be pushed up as necessary. Further, in the present embodiment, the remaining portion of each peripheral edge of the punched hole 12 is sheared at the same time in the punching step. However, even when the remaining portions are sequentially sheared, the bridging portion 3 has already been cut in the cutting step. Since this is formed, the dimensional accuracy of the bridging portion 3 is not adversely affected.

Further, in this embodiment, the case where the die 15 integrally formed as shown in FIG. 2 is used is illustrated, but instead of the integral die 15, the split die 16 shown in FIG. 3 is used. Can also be used. The split die 16 has a plurality of inserts 16a corresponding to the punched holes 12 and a wall-like insert 16b interposed between the inserts 16a and corresponding to the bridging portion 3.

[0018]

Since the present invention is constructed as described above, even if the width of the bridging portion interposed between the plurality of holes is relatively small, the bridging portion can be formed with high accuracy. it can.

[Brief description of drawings]

FIG. 1 is a plan view of a hoop metal plate for explaining an embodiment of a press punching method of the present invention.

FIG. 2 is a cross-sectional view of a mold used in the press removing method described in FIG.

FIG. 3 is a cross-sectional view showing an application example of a mold used in the press punching method described in FIG.

FIG. 4 is a plan view showing a hoop metal plate having a plurality of holes that are opposed to each other via a bridge portion.

5 is a cross-sectional view of a die used in a press punching method for forming a punching hole in the hoop metal plate of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 hoop metal plate 3 bridging part 12 through hole 13 first mold 14 punch 14a groove part 14b step part 15 die 15a recess 15b wall part 16 die 16a insert 16b wall insert

Claims (1)

[Claims] 1. A press punching method for punching a plurality of holes facing each other through a bridging portion from a hoop metal plate, wherein the bridge is formed by shearing a part of each peripheral edge of the holes in the first step. Forming a tangled portion and holding the remaining portions of the peripheral edges of the punched holes in a state of being respectively connected to the hoop metal plate, and then shearing the remaining portions of the peripheral edges of the punched hole in a second step. The punching method is characterized in that the punching hole is formed by.