JPH06269887A - Method for forming metal bar stock with long size groove - Google Patents

Abstract

PURPOSE:To provide a method where a residual strain is nothing, a position of a groove is accurately made and a producing process of a metal bar stock with long size grooves can be simplified. CONSTITUTION:In a method where a long size grooved metal wire material is passed through between a pair of rolling rolls 2a, 2b, grooves are formed on the above and formed in a metal bar stock with long size grooves, a recessing part 4 corresponding to a grooves provided with a projecting line 3 in order to form a finish width of the metal wire material with the long size grooves provided with a projecting line 2 in order to form a groove is formed, the projecting line 3 is provided inside the recessing part, and the elongation of the long size metal stock to lateral directions in the internal surface of the recessing part is controlled in a time of forming the groove on the long size metal stock with rolling rolls. In such a manner, the rolling forming can be accurately executed in the dimension of the lateral direction of the formed bar stock and the precision of the groove position, because a working of slitting, etc., is un-necessary and a residual strain is not generated, so successively the press-forming can be also accurately executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a long grooved metal strip used for electronic parts such as lead frames of power transistors and precision machine parts.

[0002]

2. Description of the Related Art Conventionally, when a long grooved metal strip a having grooves b and b as shown in FIG. The long metal material c formed in step 1 is formed by passing it between a pair of rolling rolls d and e as shown in FIG.
In this rolling, the elongation of the material in the width direction is not constant, so
Both side edges of the strip a are cut with a slitter to a specified width and then pressed to be used as a lead frame or the like.

[0003]

When both side edges of the strip a are cut by the slitter to finish the width dimension, a residual strain due to the slitter blade is generated in the strip a, and this strain is generated in the subsequent pressing step. However, the material a warps, flatness is impaired and precise press molding cannot be performed. Further, it is difficult to accurately set the relative positional relationship between the slitter blade and the groove b, and the groove position of the strip c is difficult to set. It had the drawback of poor accuracy.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks and to provide a method capable of simplifying the manufacturing process of a long grooved metal strip having no residual strain and having an accurate groove position.

[0005]

According to the present invention, there is provided a method for forming a long grooved metal strip by passing a long metal material between a pair of rolling rolls to form a long grooved metal strip. A rolling roll provided with a ridge for forming a groove is provided with a concave portion corresponding to the finishing width of the long grooved metal strip, and the ridge is provided in the concave portion. When the groove is formed in the material, the elongation of the elongated metal material in the width direction is restricted by the inner surface of the recess to achieve the above object.

[0006]

When a prepared long material having a predetermined width and a predetermined plate thickness passes between a pair of rolling rolls, a groove is formed in the long material. One of the rolling rolls has a long grooved metal. Since a concave portion corresponding to the finished width of the strip material is formed and a protrusion for forming the groove is provided in the concave portion, the length extended in the width direction by the protrusion when rolling is performed. The length of the scale material is limited by the inner wall surface of the recess. As a result, the width of the formed strip is accurate and the positional relationship with the groove is finished accurately, and there is no need to cut the strip with a slitter, so that residual strain does not occur in the strip.

[0007]

Embodiments of the present invention will be described with reference to the drawings.
In FIG. 3, reference numeral 1 denotes a long material formed of pure copper, copper alloy, permalloy or the like in a rectangular cross section with a predetermined width and a predetermined plate thickness. The long material 1 is formed by a pair of rolling rolls 2a and 2b. It is formed into a long metal strip having a groove similar to that shown in FIG. As shown in FIG. 4, one rolling roll 2a is provided with a ridge 3 for forming a groove, and the ridge 3 is provided inside the recess 4 formed in the rolling roll 2a. did.

When the long material 1 is rolled between the rolling rolls 2a and 2b, the material 1 extending in the width direction by rolling is regulated by the inner wall surface of the recess 4 as shown in FIG.
Since the molded long metal material has a precise width dimension, the distances A and B from the groove 5 to the side edges are also accurately finished. The number and shape of the grooves 5 are arbitrary.

The width of the rolling rolls 2a and 2b having the above structure is 30.
mm, a plate thickness 1.5 mm, a long material 1 of pure copper having a rectangular cross section is passed, two grooves 5 having a width of 1 mm and a depth of 1 mm are formed in the material, and a width A is 32 mm and a plate thickness is 1.3 mm. B = 1
When finished to 0.5 mm, | AB | <0.05,
The width of the strip was also within the range of 32 ± 0.1. In this case, the depth Tr of the rolling roll recess 4 was set to be smaller than a predetermined plate thickness of 1.3 mm and larger than 0.65 mm.
This long grooved metal strip was press-molded to form a lead frame, but since there was no residual strain, it did not warp during pressing and could be pressed accurately.

[0010]

As described above, according to the present invention, when a long metal material is passed between a pair of rolling rolls to form a long metal strip having grooves, the grooves are formed. A width corresponding to the finished width of the long grooved metal strip is formed on the rolling roll provided with the ridge, and the ridge is provided in the recess to form the width of the long material accompanying the formation of the groove. Since the elongation in the direction is regulated, the width dimension and groove position accuracy of the formed strip can be accurately formed, and there is no need for processing such as slitting, so residual distortion does not occur and subsequent press forming is possible. There is an effect that it can be done accurately.

[Brief description of drawings]

FIG. 1 is a perspective view of a long metal strip with grooves.

FIG. 2 is a sectional view of a conventional molding method.

FIG. 3 is a side view of an embodiment of the present invention.

4 is a sectional view taken along line AA of FIG.

[Explanation of symbols] 1 long metal material 2a, 2b rolling roll
3 and 3 ridge 4 concave 5 groove

Claims (2)

[Claims] 1. A method of forming a groove in a long metal material by allowing a long metal material to pass between a pair of rolling rolls, and forming a long grooved metal strip, wherein a ridge for forming the groove is provided. When forming a recess corresponding to the finished width of the elongated grooved metal strip on the rolling roll and providing the protrusion in the recess, and forming the groove in the elongated metal material by a rolling roll A method for forming a long grooved metal strip, wherein the inner surface of the recess is adapted to restrict the elongation of the long metal material in the width direction. 2. The method for forming a long-section metal cross-section strip according to claim 1, wherein the depth of the recess is smaller than the thickness of the long metal material.