JP2012106276A - Method for processing irregularly sectioned strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for processing an irregularly sectioned strip, capable of stably forming thick plate portions on both lateral sides thereof.SOLUTION: In the method for processing an irregularly sectioned strip 5 having a cross-sectional shape including a thick plate portion 3, 3a with large thickness and a thin plate portion 4 with small thickness, the plate thickness of the thick plate portion 3, 3a being 0.7 mm or less, and the thick plate portions 3a, 3a being located on both lateral sides of the strip, in irregular shape processing from a flat strip 1 by plastic deformation, the irregular shape processing is performed using an irregular shape processing flat strip 30 having swollen portions 31, 31 in which the plate thickness of both ends of the flat strip 1 is larger than the plate thickness of the center.

Description

  The present invention relates to a method for processing a deformed strip used for a lead frame with a heat sink or the like.

  As a method for processing a deformed strip having an irregular cross section, there are a method by cutting (for example, see Patent Document 1) and a method by roll rolling or die rolling (for example, see Patent Document 2).

  Cutting is a method of forming a groove by cutting. Since cutting waste is generated, the amount of cutting is small, and it is difficult to form by other plastic processing methods (roll rolling, die rolling), the groove width is narrow, It is suitable for processing thin grooves having a shallow depth, for example, microgrooves in which the thickness of the thick plate portion is 0.2 mm or less, the thickness of the thin plate portion is 0.1 mm or less, and the width of the thin plate portion is 0.8 mm.

  However, when the difference between the thickness of the thick plate and the thin plate is large, or when the width of the thin plate is wide, processing by roll rolling or the like is suitable due to the problem of surface roughness due to the generation of cutting waste and cutter marks. Yes.

  In the processing by rolling, as shown in FIG. 3, a material 1 made of flat strips having a uniform thickness is used. As shown in FIG. 4, the rolling is performed by moving a coil around which the material 1 is wound on a feeding device 10 and moving the material 1 to a rolling mill 14 and a winding device 11.

  The rolling mill 14 is generally configured by combining a groove roll 12 and a flat roll 13, and by continuously rolling the material 1 with the groove roll 12 and the flat roll 13, a cross-sectional portion is formed in the width direction. The deformed strip 5 having a different thickness is processed.

  As shown in FIG. 5, the groove roll 12 is formed with a groove portion 15 and a convex portion 16. By rolling the raw material 1 with the groove roll 12 and the flat roll 13, the portion of the groove roll 12 that passes through the groove portion 15 is formed in a thick state, and the portion that passes through the convex portion 16 other than the groove portion 15. The plate thickness is formed in a thin state. As a result, the deformed strip 5 having the thick plate portion 3 and the thin plate portion 4 is formed.

  The deformed strip 5 thus formed differs in the degree of processing (change in plate thickness before and after processing) of the thick plate portion 3 and the thin plate portion 4. The thin plate portion 4 has a high degree of processing because the plate thickness is reduced, and the thick plate portion 3 is thicker than the thin plate portion 4 and thus has a low processing degree. Since the difference in the degree of processing brings about a difference in material strength and hardness, annealing is performed once, and then finish rolling is performed. After finish rolling, the product is slit to the specified width dimension, and further corrected to remove harmful strains by finish rolling, slits, etc., to become a product.

JP 2007-7834 A JP 2000-24742 A

  By the way, in the deformed strip processing in which the thickness of the thick plate portion 3 is thin and the width is narrow, the conventional technology causes a phenomenon that the plate thickness of the thick plate portions 3a on both sides of the deformed strip width decreases toward the outside. This is because the thickness is small and the degree of processing is small, and the material easily escapes to the outside. Further, the groove roll 12 may be deformed, and the plate thickness becomes thin due to so-called edge drop.

  FIG. 6 shows an image diagram of the target shape and the workpiece shape. FIG. 6A shows a target shape, and there is no reduction in the plate thickness of the thick plate portions 3a and 3a on both sides of the width where the plate thickness decreases toward the outside. However, in actual processing, as shown in FIG. 6 (b), plate thickness decreasing portions 19 and 19 are generated in the thick plate portions 3a and 3a on both sides of the width, as shown in the target shape shown in FIG. 6 (a). The thickness is not constant.

  If a predetermined plate thickness cannot be ensured, problems such as punching and plating as a lead frame will occur, leading to problems such as inability to use the lead frame.

  The present invention has been devised in order to solve the above-mentioned problems, and an object of the present invention is to provide a method for processing a deformed strip that enables stable forming of thick plate portions on both sides of the plate width. is there.

  In order to solve the above-mentioned problems, the deformed strip processing method of the present invention is a deformed strip having a thick plate portion with a thick cross section and a thin plate portion with a thin plate thickness, and the plate thickness of the thick plate portion is 0. In the processing method of a deformed strip having thick plate portions on both sides of the plate width of 7 mm or less, when deforming the flat strip by plastic deformation, the deformed strip having a bulging portion in which the plate thickness at both ends of the flat strip is thicker than the central plate thickness It is characterized by being deformed using a processing strip.

  Further, the deformed flat strip is compressed in the width direction by a plate thickness improving device composed of a width direction compression roll provided in the preceding stage of the rolling machine to be deformed, and the plate thickness at both ends in the width direction is greater than the plate thickness at the center portion. It is preferable that the thickened bulge portion is formed and formed, and the deformed flat strip is deformed by the rolling mill.

  Further, the profile processing flat strip is formed by forming a bulge portion in which both end portions in the width direction are thicker than the center portion by a plate thickness improving device comprising a roll provided in a preceding stage of the rolling mill for profile processing. It is preferable that the working strip is deformed by the rolling mill.

  Moreover, it is preferable that the plate thickness for both ends of the profile processing is 5 to 25% thicker than the center plate thickness.

  According to the modified strip processing method of the present invention, it is possible to stably form the thick plate portions on both sides of the plate width.

It is the schematic which shows the processing method of the profile strip which concerns on this invention. It is sectional drawing of the width direction of the flat strip for profile processing used for this invention. It is sectional drawing of the width direction of a raw material. It is the schematic which shows the processing method of the conventional deformed strip. It is the schematic which shows the state of the groove roll and flat roll in a rolling part. It is an image figure of a deformed strip, (a) is an image figure of a target shape, (b) is a board thickness reduction image figure of the thick board part of the width both sides.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Preferred embodiments of the invention will be described below with reference to the accompanying drawings.

  In the present embodiment, as shown in FIG. 5, the cross section is a deformed strip 5 having a thick plate portion 3 having a thick plate thickness and a thin plate portion 4 having a thin plate thickness, and the plate thickness of the thick plate portion 3 is 0.7 mm or less. In this method, the deformed strip 5 having the thick plate portions 3a, 3a on both sides of the plate width is deformed by plastic deformation.

  FIG. 1 shows an outline of profile processing for processing the profile strip 5 from the material 1.

  As shown in FIG. 1, an apparatus for performing profile processing includes a feeding device 10, a sheet thickness improving device 20, a rolling mill 14, and a winding device 11 that are arranged in order in the rolling direction (arrow direction shown in the drawing). .

  The delivery device 10 is a device on which the coiled material 1 is placed, and the material 1 is delivered from the delivery device 10. The raw material 1 is a material before being processed into the deformed strip 5, and a flat strip having a uniform plate thickness is used as shown in FIG.

  The rolling mill 14 is configured by vertically combining a groove roll 12 having a horizontal axis and a flat roll 13, and the groove roll 12 and the flat roll 13 are rotated around the horizontal axis by a driving device (not shown). Is driven to rotate.

  As shown in FIG. 5, the upper groove roll 12 has a smooth outer peripheral surface, a groove 15 for forming the thick plate portions 3, 3 a of the deformed strip 5 on the smooth surface, and a thin plate of the deformed strip 5. The convex part 16 which shape | molds the part 4 is formed. The groove 15 is composed of, for example, a horizontal portion and an inclined portion, and the convex portion 16 is composed of, for example, an inclined portion and a horizontal portion. The lower flat roll 13 has a smooth outer peripheral surface.

  A plate thickness improving device 20 is provided in the front stage of the rolling mill 14. The plate thickness improvement device 20 is a device for forming the material 1 so that the plate thickness at both ends in the width direction is larger than the plate thickness at the center portion.

  The plate thickness improving device 20 is configured, for example, by being disposed on both sides in the width direction of the material 1 and provided with a pair of width direction compression rolls that compress both width ends of the material 1 so as to be rotationally driven. Alternatively, a pair of upper and lower forming rolls that are disposed on both upper and lower surfaces in the width direction of the material 1 and that form both end portions of the width of the material 1 to be thicker than the central portion are configured to be rotatably driven.

  The winding device 11 is a device that winds the processed profile strip 5 into a coil shape.

  When deforming the deformed strip 5 using this apparatus, first, the coiled material 1 is first applied to the feeding apparatus 10 and the material 1 is continuously connected to the plate thickness improving apparatus 20 provided in the front stage of the rolling mill 14. To supply.

  The raw material 1 supplied to the plate thickness improving device 20 is compressed in the width direction by the width direction compression roll of the plate thickness improving device 20, and as shown in FIG. It is formed into a deformed flat strip 30 having bulge portions 31, 31. Or it shape | molds so that the width direction both ends may become thick with the forming roll of the plate | board thickness improvement apparatus 20, and the width | variety both ends are shape | molded in the profile processing strip 30 which has plate | board parts 31 and 31 whose plate | board thickness is thicker than the center part 32. Is done.

  Next, the deformed flat strip 30 is supplied to the rolling mill 14.

  The profile processing strip 30 supplied to the rolling mill 14 is sandwiched and rolled between the groove roll 12 and the flat roll 13 as shown in FIG. 5, and the thickness of the portion passing through the groove 15 is thick. The plate thickness of the portion that passes through the convex portion 16 other than the groove portion 15 is formed to be thin. As a result, the deformed strip 5 having the thick plate portions 3a, 3a on both sides of the width and the thick plate portion 3 and the thin plate portion 4 in the width direction is formed. The rolled profile strip 5 is wound into a coil shape as a finished product by the winding device 11.

  At this time, in the profile processing by the rolling mill 14, the bulging portions 31, 31 of the profile processing flat strip 30 are positioned at the thick plate portions 3 a, 3 a on both sides of the profile strip 5 shown in FIG. , 31 covers the amount of edge drop due to rolling, and suppresses a reduction in plate thickness. For this reason, as shown in FIG. 6 (a), the deformed strip 5 after processing has a small reduction in the thickness of the thick plate portions 3a, 3a at both ends of the width, and can be deformed to a substantially target shape. That is, by forming the bulging portions 31 and 31 at both ends of the width and increasing the thickness, an amount of material corresponding to the edge drop portion of the width-end thick plate portions 3a and 3a can be secured in the processed portion. Reduction in sheet thickness can be suppressed.

  In other words, the plate thickness improving device 20 is installed in the rolling direction in the preceding stage of the rolling mill 14, and the both width ends of the material 1 are bulging thicker than the central plate thickness by the width direction compression roll or the forming roll of the plate thickness improving device 20. By forming the deformed flat strip 30 formed with the portions 31 and 31, when the deformed flat strip 30 is rolled by the rolling mill 14, the bulging portions 31 and 31 cover the edge drop amount due to rolling and the plate Thickness reduction can be suppressed, and stable forming of the thick plate portions 3a and 3a at both ends of the width becomes possible.

  In the experiment, about 5 to 25% of the increase in the plate thickness with respect to the central portion 32 at both ends of the width became a good shape by deforming. The thickness varies depending on the thickness, width, number of grooves, material thickness, etc. of the deformed strip, but if the increase in the thickness is less than 5%, the amount of material is insufficient, and after the rolling, the thick plates on both sides of the width Cracks and constriction occur in the width direction in 3a and 3a, and the effect of improving the plate thickness is thin and the product does not become a product.

  On the other hand, when the plate thickness is increased by 25% or more, the amount of material is large, the degree of processing of the bulging portions 31 and 31 at both ends in the width direction is increased as compared with the width direction central portion 32, and the thickness portions 3a and 3a are increased in the longitudinal direction. Elongation increased, the difference in elongation in the longitudinal direction depending on the width position increased, and deformation of the processed material such as local undulation and undulation increased, making it unsuitable as a product. In other words, the amount of material increases, the balance between the elongation in the longitudinal direction of the thick plate portion and the elongation of the thin plate portion is lost, the wavy phenomenon of the thick plate portion, cracks in the thin plate portion, etc. occur, and the product cannot be used. Become.

  Therefore, an increase in the thickness of about 5 to 25% is effective in improving the thickness of the thick plate portions 3a and 3a at both ends.

  As a result of some experiments, the width of the thick plate portions 3a and 3a on both sides of the plate width is 3 to 4 mm, the plate thickness of the thick plate portion 3 is 0.7 mm or less, and the plate thickness of the thin plate portion 4 is 0.2 mm or less. If the width of the thin plate portion 4 is 3 to 10 times the width of the plate portion 3, the increase in the plate thickness at both ends of the raw plate width is about 5 to 25%, and the thick plate portions 3a and 3a on both sides of the plate width are formed. There will be no hindrance.

  As described above, according to the present invention, the deformed strip 5 having the thick plate portion 3 having a thick cross section and the thin plate portion 4 having a thin plate thickness, and the plate thickness of the thick plate portion 3 is 0.7 mm or less, In the processing method of the deformed strip 5 having the thick plate portions 3a and 3a on both sides of the width, when the deformed processing is performed from the material 1 by plastic deformation, the bulging portions 31 and 31 where the thickness of both ends of the material 1 is thicker than the thickness of the central portion Since the profile processing is performed using the profile processing flat strip 30, the thick plate portions 3a and 3a on both sides of the plate width can be stably formed.

  Further, according to the present invention, the conventional method has caused the shape defect of the thick plate portions on both sides of the plate width. However, the adaptation of the present invention can eliminate the shape defect and enable stable machining. As a result, the function as a lead frame can be exhibited, and the number of defective materials can be reduced, thereby reducing the waste of materials and energy.

  In this embodiment, the grooved roll 12 and the flat roll 13 are combined, and the processing method of the deformed strip 5 having the thick plate portions 3 and 3a having a thick cross-sectional shape and the thin plate portion 4 having a thin plate thickness on one surface of the material 1. However, the present invention is not limited to this combination, and a pair of groove rolls 12 is combined to form a thick plate portion having a thick cross section and a thin plate portion having a thin plate thickness on both surfaces of the material 1. The same effect can be obtained even if there is a method for processing a deformed strip.

1 Material (Plain)
3, 3a Thick plate portion 4 Thin plate portion 5 Profile strip 12 Groove roll 13 Flat roll 14 Rolling mill 20 Plate thickness improvement device 30 Profile processing strip 31 Swelling portion 32 Central portion

Claims (4)

A method for processing a deformed strip having a thick plate portion having a thick plate section and a thin plate portion having a thin plate thickness, and having a plate thickness of 0.7 mm or less and a thick plate portion on both sides of the plate width. In
When deforming a flat strip by plastic deformation, the deformed strip is processed by using a deformed flat strip having a bulging portion in which the plate thickness at both ends of the flat strip is thicker than the central plate thickness. Method.   The profile processing strip is compressed in the width direction by a plate thickness improving device comprising a width direction compression roll provided in the front stage of the rolling machine for profile processing, and the thickness at both ends in the width direction is thicker than the thickness at the center portion. The deformed strip processing method according to claim 1, wherein the deformed strip is formed by forming a bulging portion, and the deformed flat strip is deformed by the rolling mill.   The profile processing strip is formed by forming a bulge portion whose width direction both end portions are thicker than the center portion with a plate thickness improvement device comprising a roll provided in the preceding stage of the rolling mill for profile processing. The method for processing an irregular strip according to claim 1, wherein the strip is deformed by the rolling mill.   The method for processing a deformed strip according to any one of claims 1 to 3, wherein the deformed flat strip has a thickness at both ends in the width direction that is 5 to 25% thicker than a center plate thickness.

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