JP2918238B2 - Side cutting method for metal band - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a metal strip side cutting method for correcting the width dimension of a metal strip used for manufacturing a lead frame or the like.

(Prior art) Lead frames and various contact parts are manufactured by subjecting a long metal strip to processing such as press punching, but the metal strip provided as a processing material suffers from slitter distortion and the like. There is a dimensional error such as the side line is not completely formed in a straight line, so when manufacturing products that require high accuracy, when pressing the metal strip, The metal strip is side-cut at the same time so that regular dimensional accuracy can be obtained.

FIG. 3 is an explanatory view showing a conventional method of side-cutting a metal strip. In the drawing, reference numeral 1 denotes a metal band after the side cut, 2 denotes a punch used in the side cut, and 3 denotes a side edge position of the metal band before the side cut.
The metal strip is fed by a fixed length according to the length of the punch 2 to be dropped at one time, and is side-cut over the entire length by successively dropping by the punch 2 as shown in the figure.

In the case of side cutting, the punch 2 is pulled out by the length of the punch 2 in this manner. Therefore, in order to side cut the entire length, the punching out is performed in such a manner that the previously drawn out part and the next drawn out part partially overlap. In this case, if the blade on the end face side where the punch is pulled out is simply a straight one,
When the punch is misaligned, the misalignment directly appears as a burr or a step on the end face of the metal strip.

In order to prevent this, as shown in FIG. 3, a punch 2 is used which forms a concave portion 4 dented from the side edge of the metal strip 1 in a portion where the punch is overlapped between the previous punched portion and the next punched portion. The rear end of the punch to be pulled out next time may be located in the recess 4. Even if the punch is displaced at the time of the next punching process, since the rear end of the punch is in the concave portion 4, the displacement of the punch can be escaped, and generation of burrs and the like can be prevented.

(Problems to be Solved by the Invention) The metal strip 10 shown in FIG. 3 is obtained by side-cutting as described above, but is formed on the obtained metal strip to escape the punch mismatch. The recessed portion 4 is left.

When manufacturing a lead frame, etc., the reference holes are positioned with reference to the side edge position of the metal strip.However, in the case of stamping or plating, the metal strip is positioned. Since the processing is performed while the metal strip is being conveyed, there is a problem in handling that when a concave portion or a convex portion is formed on the side edge of the metal strip, the metal strip is likely to be caught during the conveyance.

Therefore, the present invention has been made to solve the above problems, and an object thereof is to correct a dimensional error of a metal band when manufacturing a lead frame, a contact part, and the like using the metal band. Metal strips that can be processed while forming, can obtain high-precision products, and can obtain side-cut products and the like in which the side edges of the products after the side cuts are formed in a straight line It is intended to provide a side cut method.

(Means for Solving the Problems) The present invention has the following configuration to achieve the above object.

In other words, in the side cutting method of the metal strip to correct the metal strip to a predetermined width by pulling the side edge portion with a punch while feeding the fixed length, the blade portion of the punch, after the side cut A straight blade having a linear shape in a plane, which determines a side edge of the metal band, and a flat surface extending from a front end of the straight blade to a side edge portion of the metal band that is to be dropped toward the front side of the straight blade. While the shape is formed in the shape of an arc, from the arc-shaped blade formed so that the base with the front end of the straight blade is narrower than the arc-shaped front end, from the rear end of the straight blade,
It consists of an arc-shaped blade extending in the side edge side where the metal strip is pulled out toward the rear side of the straight blade and the plane shape is formed in an arc shape. The present invention is characterized in that the blanking process is performed so that a part of the blanking process at this time partially overlaps.

In addition, an arc-shaped blade is connected to the end point of the straight blade of the punch so that the cut line of the straight blade is tangent at the end point of the straight blade. In addition, the contact position between the arc-shaped blade and the straight blade at the front end of the punch and the contact position between the arc-shaped blade and the straight blade at the rear end of the punch that are to be pulled out in the current dropping process are matched and removed. Is performed.

Hereinafter, a preferred embodiment according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is an explanatory view showing a side cutting method for a metal strip according to the present invention.

In the figure, reference numeral 10 denotes a punch for side-cutting the metal strip, 12 denotes a metal strip after the side cut, and 14 denotes a side edge position of the metal strip before the side cut. The metal strip is fed by a predetermined distance at a predetermined interval in the same manner as in the conventional example, and the side edges of the metal strip are sequentially cut out by the punch 10.

In the drawing, the position through which the blade of the punch passes is indicated by a solid line, a dashed line, and a two-dot chain line.The punch 10 used in this embodiment has a metal band after the side cut on the side facing the punched end face. A straight blade 10a having a straight plane shape defining a side edge line of 12, a small arc blade 10b formed at the front end of the straight blade 10a, and a large arc blade 10c formed at the rear end side of the straight blade 10a are provided. Become.

FIG. 2 is an enlarged view showing the passing positions of the blade lines of the small arc blade 10b and the large arc blade 10c. In FIG. 2, the thick solid line indicates a cutout line of the metal band-shaped body dropped by the small arc blade 10b and the straight blade 10a,
The broken line indicates the line through which the large arc blade 10c of the punch passes at the time of the next dropout.

As shown in the figure, the overlapping position of the punch is set such that the cross point A between the passing position of the small arc blade 10b and the large arc blade 10c is located on the side edge line of the metal strip 12. That is,
A punch line that determines a side edge line of the metal strip 12 by the punch 10 is a tangent to the small arc blade 10b and also a tangent to the large arc blade 10c, and the cross point A is the small arc blade 10b and the large arc blade 10c. Are common contact points.

Thus, the cross point A of the small arc blade 10b and the large arc blade 10c
By precisely feeding the metal strip with a constant length, a metal strip having a straight side edge line without any unevenness on the side edge can be obtained as shown in FIG.

In the above method, when the punch is displaced, the small arc blade 10
Although the cross point A between b and the large arc blade 10c is deviated from a predetermined position, the actual product obtained by this method is such that the side edge of the metal strip is straight, and the concave or convex portion is located on the side edge with the naked eye. Was unacceptable.

According to the method of performing the drop-out processing by crossing the arc-shaped blades as described above, since only the crossing is performed at one point at the overlapping position of the arc-shaped blades, burrs due to the overlap of the punch blades are generated at the time of the punch-out processing. There is also the advantage that there is no.

In addition, in the above embodiment, the blade provided at the front end of the punch 10 was set to a considerably small size, in the product of the embodiment, the metal strip was side-cut about 1 mm,
This is due to the fact that scraps do not rise when the punch is removed. That is, the small arc-shaped blade 10b is formed so as to fit within the dropout width B of the metal strip, and the small arc-shaped blade 10b is formed.
If the base is slightly narrower than the front end and is narrowed, when the side edge of the metal strip is punched, the scrap does not rise from the die and the work becomes easier. If the scrap is parallel-width, the scrap can rise diagonally in the die, but if the scrap is constricted as shown in the figure, the scrap cannot be inclined inside the die. In addition, it is possible to prevent dregs from rising.

It is not necessary to form the shape of the blade of the punch into different sizes like the small arc blade 10b and the large arc blade 10c as in the above embodiment. The curvature or size of the arc-shaped blade can be appropriately set and used.

In addition, the above-described side cutting method of the metal strip can be used when manufacturing various products such as contact parts, in addition to being used when manufacturing a lead frame.

As described above, the present invention has been described variously with reference to preferred embodiments. However, the present invention is not limited to these embodiments, and it is needless to say that many modifications can be made without departing from the spirit of the invention. That is.

(Effect of the Invention) According to the side cutting method for a metal strip according to the present invention, as described above, the punch is provided with the arc-shaped blade, and the arc-shaped blade is crossed to cut the side. Side cuts can be made with an accuracy of. Further, since no concave portion or convex portion is formed on the side edge of the side cut product, when the side cut product is processed by a processing device such as a press device or a plating device, the side edge portion can be worked without being caught. . In addition, by forming the base of the arc-shaped blade provided at the front end of the straight blade so as to be narrower than the arc-shaped front end, it is possible to prevent a scrap from rising at the time of side cutting and to perform a smooth side cut. And so on.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a side cutting method of a metal strip according to the present invention, FIG. 2 is an explanatory diagram showing an enlarged view of a passing position of a punch, and FIG. 3 is an explanatory diagram showing a conventional side cutting method. is there. 10… Punch, 10a… Linear blade, 10b… Small arc blade, 10c… Large arc blade, 12… Metal band, 14… Side edge position.

Claims (2)

(57) [Claims] 1. A side cutting method of a metal strip to correct a predetermined width dimension by dropping a side edge portion with a punch while feeding the metal strip in a fixed size. A straight blade having a straight plane shape, which determines a side edge of the metal band after the side cut, and a side edge from which a front edge of the straight blade is pulled out of the metal band toward the front side of the straight blade. An arc-shaped blade formed so that the base shape of the straight blade extends from the rear end of the straight blade from the rear end of the straight blade. It consists of an arc-shaped blade extending in the side edge side where the metal strip is pulled out toward the side and the plane shape is formed in an arc shape. Perform drop-out processing so that the part to be dropped overlaps partly A side cutting method for a metal strip. 2. An arc-shaped blade is connected to an end point of the straight blade of the punch such that a straight line of the straight blade is tangent at an end point of the straight blade. Match the contact position between the arc-shaped blade at the front end of the punch and the straight blade, and the contact position between the arc-shaped blade at the rear end of the punch and the straight blade, which is to be dropped by the current punching process. 2. The method according to claim 1, wherein the metal is stripped.