JPH06310640A - Formation of lead terminal - Google Patents

Abstract

PURPOSE:To provide a method of forming lead terminals using a press which certainly realizes formation of lead terminals without any bending even when leads are very thin. CONSTITUTION:An external portion, except for one end 24a side of the target lead terminal 24 is formed to a metal plate 21 and cutout portions 25, 26, 27 are formed to the portion connected to the external portion at both s ides of one end 24a by the first press working. Thereafter, the cutout portion is also formed by the second press working so that it is connected to the cutout portions 25 to 27 and to the other end 21b of the metal plate 21 and a metal plate portion 29 around the lead terminal 24 is punched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead terminal forming method for forming a lead terminal by pressing a metal plate. The present invention relates to an improvement in a lead terminal forming method, which is formed so as to be continuous with a portion.

[0002]

2. Description of the Related Art Conventionally, when forming lead terminals for electronic parts from a metal plate by pressing, the methods shown in FIGS. 4 to 6 have been adopted.

In this method, the long metal plate 1 shown in FIG. 4 is sequentially fed using the feed holes 1a to press the metal plate 1. First, as shown in FIG. 4, a rectangular through hole 2 is formed in the center of the metal plate 1 in the width direction by press working so that its longitudinal direction is along the width direction of the metal plate 1.

Next, as shown in FIG. 5, the lengthwise direction of the metal plate 1 is set so that an elongated portion 3 whose lengthwise direction is the widthwise direction of the metal plate 1 is left in the vicinity of the through hole 2. A rectangular through hole 4 extending in the width direction is formed.

After that, the metal plate is pressed so that the lead terminals 5 are left from the other end edge 1c side of the metal plate 1 of FIG. 5 so that the lead terminals are formed continuously on one end edge 1b side of the metal plate. Punch by processing. This state is shown in FIG.

As is apparent from FIG. 6, the metal plate portion 1 near the end edge 1b is passed through the third pressing step.
An elongated lead terminal 5 is formed so that one end is continuous with d.

[0007]

However, when the width of the lead terminal 5 becomes smaller as the width of the lead terminal 5 becomes smaller than the thickness of the metal plate 1, as shown by the solid line in FIG. There is a problem that the lead terminal 5 is bent toward the through hole 4 (FIG. 5) formed later, or the cross section becomes a pentagonal shape as shown in FIG. 7.

The bending of the lead terminal 5 is caused by being pulled toward the through hole 4 formed later, and the pentagonal shape is caused by crushing the back surface of the lead terminal 5. That is, as shown in FIG. 7A and FIG. 7B in a state of seeing the step of forming the through hole 4 from the tip side of the lead terminal 5,
When forming the through hole 4, the metal plate 1 is pressed by the die 6 and the stripper 7 biased upward. next,
By lowering the punch 8, the through hole 4 is formed. However, in this case, since the through hole 2 is formed, it is not possible to secure a sufficient area for the stripping margin by the stripper 7. Therefore, the elongated portion 3 of the metal plate, which finally becomes the lead terminal, is not sufficiently pressed by the stripper 7 and is drawn into the die 6 side by the punch 8 and rotated. As a result, the bottom surface portion indicated by the arrow A in the figure is deformed to have a pentagonal cross section or to be pulled toward the through hole 4.

Therefore, when the lead terminal 3 is formed by punching out a metal plate by the third pressing step, there is a tendency that the tip of the lead terminal 5 is bent in the lateral direction due to the deformation or twist of the cross-sectional shape.

An object of the present invention is to provide a method of forming a lead terminal which enables efficient and reliable production of a lead terminal having no lateral bending by press working even when the width of the lead terminal is narrow. To provide.

[0011]

DISCLOSURE OF THE INVENTION The present invention provides a lead terminal forming method for punching a metal plate by press working to form an elongated lead terminal having one end connected to a portion left on one end line side of the metal plate. A first pressing step in which a notch is formed in the metal plate on an outer peripheral portion of the target lead terminal excluding the one end side, and on portions on both sides of the one end of the lead terminal that are continuous with the outer peripheral portion; A second press step in which a metal plate portion around the lead terminal excluding one end side of the lead terminal is punched out by forming a notch that is continuous with the notch formed in the first press step and reaches the other end edge of the metal plate; And a lead terminal forming method.

[0012]

In the lead terminal forming method of the present invention, a notch is formed in the outer peripheral portion excluding one end side of the target lead terminal in the first pressing step and the portion continuous to the outer peripheral portion on both sides of the one end side of the lead terminal. Is formed. In this case, only the notch is formed in the first pressing step, and the metal plate is not punched.

In the second step, since the metal plate is not punched out in the first step, the metal plate can be reliably pressed by the stripper. Therefore, in the second pressing step, by punching the metal plate around the lead terminals as described above, it is possible to reliably obtain the lead terminals without deformation.

That is, according to the present invention, when the elongated lead terminals are formed by punching, if one side and the other side of the lead terminals are punched separately, the metal is used for punching the side to be performed later. Considering that it is difficult to press the plate securely, only the notch is formed as described above in the first pressing step, and the unnecessary metal plate portion is punched out by using the notch in the second pressing step. It has a feature.

[0015]

According to the present invention, since the metal plate is not punched in the first pressing step, the metal plate can be surely pressed by the stripper or the like when punching the metal plate in the second pressing step. Moreover, in the first pressing step, since the notch is formed in the outer peripheral portion of the lead terminal other than the one end side, the unnecessary metal plate portion around the lead terminal is surely secured by performing the second pressing step. Can be punched into.

Therefore, even if the width of the lead terminal is narrower, it is possible to reliably obtain the lead terminal free from deformation such as lateral bending.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be clarified by describing one embodiment of the present invention. With reference to FIG. 1, in this embodiment, a long metal plate 21 is prepared. Metal plate 21
Feed holes 22 are formed on the one end edge 21a side at predetermined intervals along the longitudinal direction. Similarly, on the other end 21b side, feed holes (not shown) are formed at predetermined intervals along the longitudinal direction.

In this embodiment, the metal plate 21 is progressively fed by utilizing the feed hole 22, and the following first and second pressing steps are performed. In the first pressing step, the lead terminal 24 except for the one end 24 a side of the target lead terminal 24.
A notch 25 is formed along the outer periphery of the. Also,
The cuts 26, 27 are formed so as to be continuous with the cut 25, extend on both sides of the one end 24a in the longitudinal direction of the elongated metal plate 21 as shown, and extend on the tip side toward the other end 21b. Is formed. Further, an auxiliary notch 28 is formed between the tip of the lead terminal 24 and the other end edge 21b so as to extend in the length direction of the metal plate 21.

The cuts 25 to 28 are all formed by partially cutting the metal plate 21 with a cutting blade in a state where the metal plate 21 is pressed by a die and a stripper in a press machine. No partial removal is done. Therefore, even if the width of the lead terminal 24 is narrow, it is difficult for the lead terminal 24 to be excessively twisted as in the conventional method.

The portion 29 surrounded by the cuts 25 to 27 is slightly bent from the main surface of the metal plate 21 as shown in FIGS. 2 and 3 along with the cutting. As is clear from FIGS. 2 and 3, the metal plate portion 29 is continuous with the metal plate 21 on both sides of the auxiliary notch 28.

Next, in a second pressing step, a notch is formed so that the notches 26 and 27 reach the other end edge 21b side of the metal plate 21, and the metal plate portion 29 around the lead terminal 24 is punched out. In this way, as shown in FIG. 1, the elongated lead terminal 24 can be formed without causing lateral bending.

In the above embodiment, the notches 26 and 27 formed in the first pressing step not only extend in the longitudinal direction of the metal plate 21 on both sides of the one end 24a of the lead terminal 24, but also on the other end edge 21b side. However, if notches are formed in the outer peripheral portion of the remaining portion of the lead terminal 24 excluding the one end 24a and the portions extending in the longitudinal direction of the metal plate 21 on both sides of the one end as well. Similar to the above embodiment, the metal plate portion 29 can be punched out without causing the lead terminal 24 to be laterally bent in the second pressing step.

Further, the auxiliary notch 28 is provided with the lead terminal 24 of the metal plate portion 29, as shown in FIGS.
It has been provided to facilitate the separation from the above, but it may not be provided in particular.

Further, in the above embodiment, one lead terminal 24 is formed by carrying out the first and second pressing steps, but in the lead terminal forming method of the present invention, the notch is formed in the first pressing step. Are only formed,
Since the metal plate is not removed, it is possible to easily form a plurality of elongated lead terminals by collectively performing the first and second pressing steps. Therefore, it is possible to reduce the number of molds required for forming the lead terminals and reduce the size thereof.

[Brief description of drawings]

FIG. 1 is a partially cutaway plan view for explaining a step of forming a lead terminal in an example.

FIG. 2 is an enlarged cross-sectional view showing a portion along line AA in FIG.

FIG. 3 is a partially cutaway perspective view showing a state after completion of a first pressing step in the example.

FIG. 4 is a partially cutaway plan view showing a state in which a first through hole is formed in a conventional lead terminal forming method.

FIG. 5 is a partially cutaway plan view showing a state in which a second through hole is formed in the conventional lead terminal forming method.

FIG. 6 is a partially cutaway plan view showing a state in which lead terminals are formed by a conventional lead terminal forming method.

7A and 7B are cross-sectional views for explaining deformation of a cross-sectional shape of a lead terminal constituent portion when a through hole is formed by a conventional method.

[Explanation of symbols]

 21 ... Metal Plate 21a ... One End Edge of Metal Plate 21b ... Other End Edge of Metal Plate 24 ... Lead Terminal 24a ... One End of Lead Terminal 25, 26, 27 ... Notch

Claims (1)

[Claims] 1. A method of forming a lead terminal, comprising punching a metal plate by press working to form an elongated lead terminal having one end connected to a portion left on one end line side of the metal plate. Formed by a first pressing step of making a notch in an outer peripheral portion of the lead terminal excluding the one end side and a portion continuous with the outer peripheral portion on both sides of the one end of the lead terminal, which is formed by the first pressing step. In a series of cuts,
A second pressing step of forming a notch extending to the other end edge of the metal plate and punching out a metal plate portion around the lead terminal excluding the one end side of the lead terminal. .