JP2012000631A - Ripping cutting punch mold of punch press, corner cutting punch mold and method of forming plate material opening - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ripping cutting punch mold of a punch press which performs ripping cutting of a plate material to thereby cut it, or to form a long hole or an opening in the plate material, and the like, leaving almost no projection-shaped trace in the joint part of punching and also leaving almost no projection-shaped trace even at the terminal of clipping cutting or the like.SOLUTION: The ripping cutting punch mold 1 includes a punching blade part 4 and a cutting blade part 5 which are arranged parallel with a ripping direction, the side surfaces of the punching blade part 4 and the cutting blade part 5 being positioned on the same surface and lower edges of the side surfaces being a punching edge 8 and a cutting edge 10 respectively. The punching blade part 4 protrudes with a step in a position lower than the cutting blade part 5. The cutting blade part 5 inclines further upwards the further a bottom surface 9 is away from the punching blade part 4, and a middle part in the bottom surface 9 in the arrangement direction of the punching blade part 4 and the cutting blade part 5 is a concave part 9a having a shape in which the side surfaces are upwardly recessed. The outline of the side surface shape of the concave part 9a has a shape in which an angle of inclination decreases with respect to the horizontal the further the outline is away from the punching blade part 4.

Description

  The present invention uses a punch press die for cutting and corner cutting used for cutting, forming a long hole, making a hole, etc., by cutting a plate material, and using these punch dies. The present invention relates to a method for forming openings in a plate material.

  When cutting a plate material, forming a long hole, or drilling using a punch press, there is usually a method in which a punch die having a rectangular cross section is used as the die and a large number of punch holes are continuously processed. Taken. In this method, as shown in FIG. 15, the upper portion of the cut surface 100 of the plate material W remains as a small protruding trace 102 without forming the sag 101 at the joint portion of the punch hole that is continuously opened. There is a problem. As shown in FIG. 15C, the cut surface 100 obtained by punching becomes a sag 101, a shear surface 103, and a fracture surface 104 in this order from the punch entry side.

  As a punching method for eliminating such traces 102 of the seam portion, a punching die for additional cutting having a cutting blade portion whose bottom surface is inclined with respect to the horizontal is used, and the cutting blade portion does not punch a plate material. There has been proposed a method in which the next cut is processed after the previous cut only by making the cut (for example, Patent Documents 1 and 2). Thus, according to the processing method which inserts a cut | disconnection sequentially, a cut surface is finished beautifully continuously. In addition, these proposed punching dies for additional cutting have a punching blade part separately from the cutting blade part, and the punching part is formed by the cutting blade part by the punching process. It is designed to punch out the inner part.

Japanese Patent No. 3401908 JP 2003-230920 A

  Since the above-mentioned conventional cutting die for additional cutting has a fixed cutting angle at the cutting blade portion, a certain amount of sagging is formed even at the base end of the cutting. Therefore, in the case of punching the portion where the cut is not formed and the portion where the cut is made with a general punch die having a rectangular cross section at the end of the cut-off cutting, etc. Although the degree is smaller than the case where the punch holes are continuously processed using only a general punch die at the joint portion between the incision formed with the punch hole formed with the general punch die, the above-mentioned A protruding mark 102 (FIG. 15) similar to that of FIG.

  In the case where a rectangular opening is formed in a plate material using a punching die for additional cut, a method shown in FIG. 16 has been conventionally employed. That is, a common punch mold is used to open a discard hole 111 at the corner portion of the target opening 110 (FIG. 2A), and the follow-up cutting punch mold is used following the discard hole 111. A cut-off cut is performed toward the adjacent discard hole 111 (FIG. 5B), and a cut 112 formed by the cutting blade portion is connected to the adjacent discard hole 111 to cut one side of the opening 110 ( (C). In addition, the inner part of the notch 112 formed by the previous punching process is punched by the punching blade part, and the long hole 113 is formed by connecting the punching hole. Although the figure shows a state in which only one side of the opening 110 is cut, the opening 110 is formed by cutting the other three sides in the same manner. According to this opening forming method, a protruding mark 102 (FIG. 15) remains at the joint portion between the discard hole 111 and the notch 112 formed following the discard hole 111.

The object of the present invention is to cut the plate material by cutting, forming a long hole, forming an opening, etc., and there is almost no protruding trace at the joint portion of punching, and the end of the cut and cut Is to provide a punch die for additional cut of a punch press that can be processed with almost no protruding traces remaining.
Another object of the present invention is to continuously change the stress generated in the plate material along the surface of the plate material by the cutting blade portion of the punch die at the time of punching by the punch die for additional cut, and the range in which the stress is applied. It is to prevent the boundary points between the range and the range not to be generated in a concentrated manner.
Still another object of the present invention is to make a cut in a predetermined corner shape with respect to a plate material, and a projecting trace at the joint portion of the cut by the cut blade portion of the cut die for additional cut. It is to provide a punch die for cutting a corner of a punch press that hardly remains.
Still another object of the present invention is to provide a punch die set for additional cutting and corner cutting of a punch press suitable for use in combination when opening an opening having a corner portion such as a rectangle on a plate material. is there.
Still another object of the present invention is to provide an opening forming method capable of forming an opening having a corner portion such as a rectangle in a plate material, leaving almost no protruding traces at a cut seam portion.

  The punch die for additional cutting of the punch press according to the present invention is for cutting a plate material along a continuous cutting line, arranged side by side in the additional cutting direction, and the side surfaces thereof are mutually It has a punching blade portion and a cutting blade portion, which are located on the same plane and whose lower end edge of each side surface is a punching edge and a cutting edge, and the punching blade portion is formed from the cutting blade portion. And the cutting blade portion is inclined upward as the bottom surface is moved away from the punching blade portion, and the cutting blade portion and the cutting blade portion on the bottom surface are arranged in an intermediate direction. The portion is a side-shaped concave portion that is recessed upward, and the side-line contour line of the concave portion has a shape in which the inclination angle with respect to the horizontal decreases as the distance from the punching blade portion increases.

  The punch cutting die having this configuration is used together with a die die corresponding to the punch die. A plate material is placed on the die mold, and punching is performed on the plate material by punching down the punch mold. By this punching process, a cut is formed in the plate material at the cutting edge of the cutting blade portion. The inner part of the cut in the plate material, that is, the part located below the cutting blade part is pushed downward by the bottom surface of the cutting blade part, and the cutting is bent downward toward the tip side, that is, the punching blade part side. It becomes a piece. This cut piece is connected to the base end, that is, the opposite end to the punching blade portion, where the cut is not formed. Each punching process is performed by repeatedly punching while shifting the position of the punch die along the cutting line so that the tip of the cutting piece formed by the previous punching process is punched by the punching blade part. The plate material is cut along the cutting line. Further, the portions punched by the punching blade portion in each punching process are connected to form a long hole along the cutting line.

  The concave portion on the bottom surface of the cutting blade portion has a shape in which the inclination angle with respect to the horizontal becomes smaller as the contour line of the side surface shape moves away from the punching blade portion. Therefore, on the side of the recess that is far from the punching blade, the inclination angle is small and close to horizontal. Therefore, by setting the punching die down height so that the portion far from the punching blade portion of the recess is the height of the top surface of the plate material before punching, the recess is formed on the bottom surface of the cutting blade portion. The base end of the cut piece formed by punching can be made nearly horizontal compared to the case of punching with a punch die having no punch. If the base end of the cut piece is close to the horizontal, there is almost no sagging at the base end of the cut. Therefore, when performing cut-off cutting, almost no protruding traces remain in the joint portion of the cut.

In the punch die for additional cut of the punch press according to the present invention, the concave portions on the bottom surface of the cutting blade portion are respectively provided through curved surface portions that are convex downward with respect to the slope portions continuing on both sides in the arrangement direction. It is good that they are connected smoothly. Note that “smoothly connected” means that the curve forming the cross section has a shape that can be differentiated at the connecting portion.
If the concave portion on the bottom surface of the cutting blade portion and the portions continuing on both sides thereof are smoothly connected, the stress generated in the plate material by the cutting blade portion of the punch die during punching with the punch die for additional cutting, The state can be changed continuously along the surface of the plate. That is, the boundary points between the range where the stress is applied and the range where the stress is not applied are not concentrated. Thereby, it can prevent that a board | plate material deform | transforms into shapes other than the defined shape.

  The punch die for cutting a corner of the punch press according to the present invention is for cutting a plate material along a predetermined corner shape, and the lower end edge of the outer surface is a punching edge along the corner shape. A punching blade portion, and two cutting blade portions each having a cutting edge extending in the extending direction of the punching edge in a planar shape with the lower end edge of one side surface extending from both ends of the punching edge, The punching blade portion protrudes downward from the cutting blade portion, and the cutting blade portion is inclined upward as the bottom surface moves away from the punching blade portion. The intermediate portion in the direction in which the blades are arranged is a concave portion having a side shape that is recessed upward, and the contour line of the side surface shape of the concave portion has a shape in which the inclination angle with respect to the horizontal decreases as the distance from the punching blade portion increases. It is characterized by that.

  The corner cutting punch mold having this configuration is used in combination with a die mold corresponding to the punch mold. A plate material is placed on the die mold, and punching is performed on the plate material by punching down the punch mold. By this punching process, a corner-shaped cut is formed in the plate material by the punching edge of the punching blade portion and the cutting edge of the cutting blade portion. The inner part of the cut in the plate material, that is, the part located below the punching blade part and the cutting blade part is pushed downward by the bottom surfaces of the two blade parts to form a bending-shaped cutting piece. This cut piece is connected to the base end, that is, the opposite end with respect to the corner, where the cut is not formed.

  The concave portion on the bottom surface of the cutting blade portion has a shape in which the inclination angle with respect to the horizontal becomes smaller as the contour line of the side surface shape moves away from the punching blade portion. Therefore, on the side of the recess that is far from the punching blade, the inclination angle is small and close to horizontal. Therefore, by setting the punching die down height so that the portion far from the punching blade portion of the recess is the height of the top surface of the plate material before punching, the recess is formed on the bottom surface of the cutting blade portion. The base end of the cut piece formed by punching can be made almost horizontal compared to the case of punching with a punch die having no. If the base end of the cut piece is close to the horizontal, there is almost no sagging at the base end of the cut when performing the post-cutting with the punching die for cut-off cutting. Therefore, almost no protruding traces remain at the joint between the cut by the corner cutting punch mold and the cut by the additional cutting punch mold.

A punch die set for additional cutting and corner cutting of a punch press according to the present invention includes a punch die for additional cutting of a punch press according to claim 1 and a punch die for corner cutting of a punch press. A mold set consisting of molds. The corner cutting punch mold includes a punching blade portion that is a punching edge along a corner shape with a lower end edge of an outer surface, and a lower end edge on one side surface that extends from both ends of the punching edge. Two cutting blade portions that are formed as cutting edges extending in the extending direction of the punching edge in the shape, and the punching blade portion projects below the cutting blade portion, and the cutting blade portion Is inclined upward as the bottom surface moves away from the punching blade portion, and the intermediate portion in the direction of arrangement of the punching blade portion and the cutting blade portion on the bottom surface is a concave portion having a side shape that is recessed upward, The contour line of the side surface shape of the recess has a shape in which the inclination angle with respect to the horizontal becomes smaller as the distance from the punching blade portion increases.
By using a combination of a punch die for additional cutting and a corner cutting punch die, an opening such as a rectangle can be efficiently formed in the plate material, and the side portion of the formed opening and the corner portion In any case, it is possible to obtain a beautiful finish with almost no protruding traces remaining.

  The plate material opening forming method according to the present invention is a method using the cut-off punch die according to claim 1 or 2, and the corner-cutting punch die according to claim 3, wherein the corner cutting is performed. Includes process, parting preparation process, parting process, and punching process. In the corner cutting process, punching is performed using the punch die for corner cutting at a location that becomes a corner of an opening to be formed in the plate material, and the punching blade portion and the cutting blade portion of the punch die are used to form the plate material. This is a process of forming a corner cut and pressing the inner part of the corner cut downward to form a corner cut piece. In the additional cutting preparation process, the punching blade portion of the punching die for additional cutting is vertically overlapped with the corner cut piece, and the cutting blade portion of the punch die is cut from the corner more than the punching blade portion. Punching is performed using the punch die for additional cutting that is disposed so as to be located apart, and the corner cut piece is punched by the punching blade portion of the punch die, and the punch die is cut This is a process of forming a cut-in cut extending to the side away from the corner following the corner cut by the blade, and pushing down the inner part of the cut-off to make a cut-off cut piece. The additional cutting process is repeated a plurality of times following the additional cutting preparation process, and the additional cutting punch die is applied to the additional cutting piece formed in the additional cutting preparation process or the previous additional cutting process. Punching is performed using the punch die for additional cutting, which is arranged so that the punching blades overlap each other and the cutting blade of the punch die is located farther from the corner than the punching blade. The punching blade portion of the punch die cuts out the additional cutting piece, and the cutting blade portion of the punch die cuts out a new additional cutting cut extending from the corner to the side away from the corner. Is formed, and the inner part of the additional cut is pushed downward to form a new additional cut. The punching process is performed by sequentially performing the corner cutting process, the additional cut preparation process, and the additional cut process from the two adjacent corners toward the center between the two corners, and the final cut process performed in both directions. This is a punching process in which each uncut portion formed is punched by using a punching die other than the additional cutting punch die and the corner cutting punch die.

  According to this opening formation method for a plate material, first, a corner cutting process is used to perform punch processing at a portion that becomes a corner of an opening to be formed in a plate material using a corner cutting punch mold. As a result, a corner-shaped corner cut is formed in the plate material by the punching edge of the punching blade portion and the cutting edge of the cutting blade portion of the punch die, and the inner portion of the corner cut is formed by the punching blade portion and the cutting edge. Push down downward on the bottom of the cutting edge to make a corner cut piece. At the time of punching, set the punch die down height so that the part far from the punching blade in the recess at the bottom of the cutting blade is the height of the top surface of the plate before punching. By placing it, the base end of the corner cut piece becomes almost horizontal.

  Next, in the additional cut preparation process, the punching blade portion overlaps with the corner cutting piece formed in the corner cutting process, and the cutting blade portion is positioned farther from the corner than the punching blade portion. Punching is performed using a punching die for additional cut arranged in the above. As a result, a corner cutting piece is punched with the punching blade portion of the punch die, and a cutting edge extending toward the side away from the corner following the corner cutting at the cutting edge of the cutting blade portion of the punch die. Then, the inner portion of the additional cut is pushed downward on the bottom surface of the cutting blade portion to form a additional cut piece. Since the base end of the corner cut piece formed in the corner cutting process is nearly horizontal, when the additional cutting is performed using the punch die for the additional cut in the additional cut preparation process, Hardly occurs. Therefore, almost no protruding traces remain at the joint between the corner cut by the corner cutting punch mold and the additional cut by the additional cut punch mold.

  Following the cut-off preparation process, the cut-off process is repeated a plurality of times while shifting the position along the target cutting line. In the cut-off process, the punching die for the cut-off cutting is overlapped with the cut-off cutting piece formed in the cut-off preparation part or the previous cut-off process and the cutting blade part is punched. The punching process is performed by disposing it so as to be positioned farther from the corner than the punching blade portion. By this additional cutting process, the additional cutting piece previously formed by the punching blade part of the same punching die is punched, and from the corner following the additional cutting formed previously by the cutting edge of the cutting blade part. A new additional cut is formed that extends to the far side, and the inner portion of the additional cut is pushed downward on the lower surface of the cutting blade to form a new additional cut. At the time of punching, set the punch die down height so that the part far from the punching blade in the recess at the bottom of the cutting blade is the height of the top surface of the plate before punching Then, make the base end of the additional cut piece close to the horizontal. As a result, almost no sagging occurs at the base end of the additional cut, and almost no protruding traces remain at the joint of the additional cut.

  The above corner cutting process, additional cutting preparation process, and additional cutting process are performed in order from the two adjacent corners toward the center between both corners, leaving an uncut portion at the center of each side between the corners. It is assumed that Both sides of the uncut portion are a pair of additional cut pieces formed by the final cut process performed at the end in both directions. In the punching process, the uncut portion is punched using a punching die other than the post-cutting punch die and the corner cutting punch die, thereby completing the opening. Since there is almost no sag at the base end of each additional cut formed by the last cut process, the additional cut is also performed when punching the additional cut piece with a punching die. There is almost no protruding trace at the joint between the punch hole and the punch hole by the punching die.

  The punch die for additional cutting of the punch press according to the present invention is for cutting a plate material along a continuous cutting line, arranged side by side in the additional cutting direction, and the side surfaces thereof are mutually It has a punching blade portion and a cutting blade portion, which are located on the same plane and whose lower end edge of each side surface is a punching edge and a cutting edge, and the punching blade portion is formed from the cutting blade portion. And the cutting blade portion is inclined upward as the bottom surface is moved away from the punching blade portion, and the cutting blade portion and the cutting blade portion on the bottom surface are arranged in an intermediate direction. The side portion is a concave portion that is recessed upward, and the contour line of the side surface shape of this concave portion has a shape in which the inclination angle with respect to the horizontal decreases as the distance from the punching blade portion increases, so the plate material is additionally cut. When cutting, forming long holes, forming openings, etc. Most left without trace of protruding in the joint portions of the machining, moreover it can be processed without leaving little protruding traces even at the end or the like of the cut-out cutting.

  In the punch die for additional cut of the punch press, the concave portions on the bottom surface of the cutting blade portion are smoothed with respect to the slope portions continuing on both sides in the alignment direction, respectively, via downward curved surface portions. If it is connected to, the stress generated in the plate material by the cutting blade part of the punch die at the time of punching by the punch die for additional cut is continuously changed along the surface of the plate material, so that the stress is applied. Do not concentrate the boundary points with non-range.

  The punch die for cutting a corner of the punch press according to the present invention is for cutting a plate material along a predetermined corner shape, and the lower end edge of the outer surface is a punching edge along the corner shape. A punching blade portion, and two cutting blade portions each having a cutting edge extending in the extending direction of the punching edge in a planar shape with the lower end edge of one side surface extending from both ends of the punching edge, The punching blade portion protrudes downward from the cutting blade portion, and the cutting blade portion is inclined upward as the bottom surface moves away from the punching blade portion. The intermediate portion in the direction in which the blades are arranged is a concave portion having a side shape that is recessed upward, and the contour line of the side surface shape of the concave portion has a shape in which the inclination angle with respect to the horizontal decreases as the distance from the punching blade portion increases. Therefore, the corner shape defined for the plate material Can contain cut, hardly remains trace the joint portion of the cut by the cutting blade portion of the cut and add cut cutting punch.

  The punch die set for additional cutting and corner cutting of the punch press according to the present invention includes a punch die for additional cutting of the punch press according to claim 1 and a punch die for corner cutting of the punch press. The corner cutting punch mold includes a punching blade portion that is a punching edge along a corner shape in which a lower end edge of an outer surface is defined, and a lower end edge on one side surface. Has two cutting blade portions each formed as a cutting edge extending in the extending direction of the punching edge in a planar shape following the both ends of the punching edge, and the punching blade portion is the cutting blade portion. Projecting further downward, the cutting blade portion is inclined upward as the bottom surface moves away from the punching blade portion, and the intermediate portion of the cutting blade portion and the cutting blade portion in the arrangement direction on the bottom surface, It is a side-shaped recess recessed upward, and the side-shape of this recess Kakusen because as the distance from the punching blade unit is shaped to have an inclination angle relative to the horizontal is smaller, suitable for use in combination when opening the opening having a corner portion such as a rectangular plate material.

  The plate material opening forming method according to the present invention includes forming a plate material opening by a punch press using the punching die for additional cut according to claim 1 or claim 2 and the corner cutting punch die according to claim 3. A method comprising a corner cutting process, a follow-up preparation process, a follow-up process, and a punching process, wherein the corner cutting process is performed at the corner cutting hole mold to be formed in a plate material. Is the process of forming a corner cut in the plate material by the punching blade part and the cutting blade part of the punch die, and pushing down the inner part of the corner cut downward to make a corner cut piece In the additional cutting preparation process, the punching blade part of the punching die for additional cutting is vertically overlapped with the corner cutting piece, and the cutting blade part of the punching die is the cutting blade part. Punching is performed using the punch die for additional cutting arranged so as to be located away from the corner, and the corner cut piece is punched by the punching blade portion of the punch die, and the punch die The cutting blade portion is formed by forming a cut-in cut extending to the side away from the corner following the corner cut, and pressing down the inner part of the cut-off cut to form a cut-off cut piece, The cut-off process is repeated a plurality of times following the cut-off preparation process, and the cut-off punch die is punched into the cut-off cut piece formed in the cut-off preparation process or the previous cut-off process. Punching is performed using the punch die for additional cutting, which is arranged such that the blade portions overlap each other and the cutting blade portion of the punch die is located farther from the corner than the punching blade portion, Same The above-mentioned cutting cut piece is punched by the punching blade portion of the die, and a new cutting cut extending from the corner to the side away from the corner is formed by the cutting blade portion of the punch die. The inner portion of the additional cut is pushed downward to form a new additional cut piece, and the punching process is performed by cutting the corner from two adjacent corners toward the center between the two corners. An uncut portion formed by the last cut process performed in the last in both directions is performed in the order of the cut process, the additional cut preparation process, and the additional cut process. Since the punching process is performed using a punching die other than the die, an opening having a corner such as a rectangle is formed on the plate material with almost no trace left on the cut seam. Can do.

(A) is a front view of a punch die for additional cut of a punch press according to an embodiment of the present invention, (B) is a partially enlarged view thereof, and (C) is a bottom view thereof. (A) is a fracture | rupture front view of the die die for additional cutting used in combination with the punch die for additional cutting, (B) is the top view. (A) is a front view of a punch die for corner cutting of a punch press according to an embodiment of the present invention, (B) is a partially enlarged view thereof, and (C) is a bottom view thereof. (A) is a fracture front view of a corner cutting die mold used in combination with the corner cutting punch mold, and (B) is a plan view thereof. (A) is a front view of a punching die for punching, and (B) is a bottom view thereof. (A) is a fracture front view of a die for punching used in combination with the punching die for punching, and (B) is a plan view thereof. FIG. 3 is a cross-sectional view showing a support structure for the punching die for additional cutting shown in FIG. 1 and the die for additional cutting shown in FIG. 2. (A)-(F) is a figure which shows each step of the opening formation method of the board | plate material concerning one Embodiment of this invention. (A)-(D) are figures which show the operation state of each step | level of the opening formation direction of the board | plate material. (A) is a plan view of a corner cut, (B) is an XB-XB cross-sectional view, and (C) is an XC-XC cross-sectional view thereof. (A) is a plan view of the additional cut, (B) is a XIB-XIB sectional view, and (C) is a XIC-XIC sectional view. It is a perspective view which shows the punching process in the opening formation method of the board | plate material. (A) is a side view of a punch die for additional cut of a punch press according to a different embodiment of the present invention, and (B) is a front view thereof. (A) is a front view of a punch die for additional cut of a punch press according to a different embodiment of the present invention, and (B) is a bottom view thereof. (A) is the top view of the cutting location of the board | plate material by the conventional additional cutting, (B) is the front view, (C) is the XVC-XVC sectional drawing. (A)-(C) are figures which show each step | level of the opening formation method of the conventional board | plate material.

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a punch die for additional cut of a punch press according to an embodiment of the present invention. This additional cutting punch mold 1 is provided with a blade 3 at the lower end of a handle 2. The blade portion 3 has a rectangular cross-sectional shape, and a punching blade portion 4 and a cutting blade portion 5 that are aligned with each other in the wide direction, that is, the cut-off direction, are formed at the lower end of the blade portion 3. Therefore, the punching blade part 4 and the cutting blade part 5 have the same thickness, and both side surfaces are the same plane. Between the punching blade part 4 and the cutting blade part 5, a groove-shaped escape recess 6 is formed that is released on both side surfaces. The inner wall surface 6a on the punching blade portion 4 side of the escape recess 6 is a surface along the vertical direction, and the inner wall surface 6b on the cutting blade portion 5 side is an inclined surface that approaches the cutting blade portion 5 toward the lower end side.

  The bottom surface 7 of the punching blade portion 4 has a planar shape with the same height, and the lower edge that is each side of the bottom surface 7 is a punching edge 8. The punching blade part 4 protrudes with a step H below the lowermost end of the cutting blade part 5.

  The bottom surface 9 of the cutting blade portion 5 is inclined upward as it moves away from the punching blade portion 4, and the portion of the bottom surface 9 in the arrangement direction of the punching blade portion 4 and the cutting blade portion 5 excluding both ends. The intermediate portion is a side-shaped recess 9a that is recessed upward. The contour line of the side surface shape of the concave portion 9a has such a shape that the inclination angle with respect to the horizontal decreases as the distance from the punching blade portion 4 increases. Specifically, the contour line of the side surface shape of the concave portion 9a is an arc having a radius R1, and the end opposite to the punching blade portion 4 of the arc has an infinitely close shape. In addition, the concave portion 9a is smoothly connected to the slope portions 9b and 9c continuing on both sides in the alignment direction via curved surface portions 9d and 9e that protrude downward. The contour lines of the side shapes of the curved surface portions 9d and 9e are arcs having radii R2 and R3, respectively. Both slope portions 9b, 9c are located on the same plane. A portion between the slope portion 9b and the escape recess 6 is a horizontal surface portion 9f. As for the cutting blade part 5, the lower end edge of the both sides is made into the cutting edge 10. FIG.

  FIG. 2 shows a die for cutting-off cutting used in combination with the punching die 1 for cutting-off. This die for cutting 11 has a substantially circular planar shape, and has a slit-shaped blade portion entry hole 12 into which the punching blade portion 4 and the cutting blade portion 5 of the punch die 1 enter. It is provided penetrating vertically. The blade entry hole 12 is a stepped hole in which the lower hole portion 12b is longer in the longitudinal direction than the upper hole portion 12a, and the blade portion 3 of the punch die 1 is fitted into the upper hole portion 12a. The cross-sectional shape is matched. One wall surface in the longitudinal direction of the upper hole portion 12a is an inclined surface 12aa in which a portion below the upper end portion retreats to the outer diameter side. The blade entry hole 12 is partitioned by a partition wall 13 in the center in the longitudinal direction, that is, the cut-off direction, and one hole portion becomes a punching through hole 14 into which the punching blade 4 of the punch die 1 enters. The other hole portion is a through hole 15 for cutting into which a tongue-like additional cut piece 96 (FIG. 8D) of the plate material W described later falls. The wall surface 13a on the side of the punching through hole 14 of the partition wall 13 is a surface along the vertical direction, and the wall surface 13b on the side of the through hole 15 for cutting is the inner wall surface of the relief recess 6 of the punch die 1 for cut-off cutting. 6b is an inclined surface corresponding to 6b.

  The upper end edge of the portion located above the punching through hole 14 in the blade entry hole 12 and the upper end edge of the wall surface 13a on the side of the punching through hole 14 of the partition wall 13 are the punch cutting die 1 for additional cut. The punching edge 16 meshes with the punching edge 8. Further, the upper edge along the cut-off direction of the portion located above the cut-through hole 15 in the blade entry hole 12 is the cut edge that meshes with the cut edge 10 of the cut die 1 for cut cut. 17

  FIG. 3 shows a punch die for corner cutting of a punch press according to an embodiment of the present invention. This corner cutting punch mold 21 is provided with a blade portion 23 at the lower end of a handle portion 22. The blade portion 23 has a substantially square cross-sectional shape, and one punching blade portion 24 and two cutting blade portions 25 are formed at the lower end of the blade portion 23. The blade part 23 and the punching blade part 24 are in contact with each other.

  The bottom face 26 of the punching blade portion 24 is a square plane having the same height, and the lower edge along two adjacent sides of the four sides of the bottom face 26 is a punching edge 27. The bottom surfaces 28 of the cutting blade portions 25 are in contact with the two sides 29A that are not the punching edges 27 of the punching blade portions 24, and the bottom surfaces 28 of the cutting blade portions 25 are mutually connected by a ridgeline boundary line 29B. Touching.

  The bottom surface 28 of the cutting blade portion 25 is inclined upward as it moves away from the punching blade portion 24, and the portion of the bottom surface 28 in the arrangement direction of the punching blade portion 24 and the cutting blade portion 25 excluding both ends. The intermediate portion is a side-shaped recess 28a that is recessed upward. The contour line of the side surface shape of the concave portion 28a has such a shape that the inclination angle with respect to the horizontal becomes smaller as the distance from the punching blade portion 24 increases. Specifically, the contour line of the side surface shape of the concave portion 28a is an arc having a radius R4, and the end opposite to the punching blade portion 24 of the arc has an almost nearly horizontal shape. In addition, the concave portion 28a is smoothly connected to the slope portions 28b and 28c continuing on both sides in the arrangement direction via curved surface portions 28d and 28e that protrude downward. The contour lines of the side shapes of the curved surface portions 28d and 28e are arcs having radii R5 and R6, respectively. The lower edge of the cutting blade portion 25 that follows the punching edge 27 of the punching blade portion 24 is a cutting edge 30.

  FIG. 4 shows a corner cutting die mold used in combination with the above corner cutting punch mold 21. The corner cutting die 31 has a substantially circular planar shape, and has a substantially square blade portion entry hole 32 into which the punching blade portion 24 and the cutting blade portion 25 of the punch die 21 enter. , Are provided penetrating up and down. The blade entry hole 32 is a stepped hole in which the lower hole 32b has a larger planar shape than the upper hole 32a, and the blade 23 of the punch die 21 is fitted into the upper hole 32a. It has a cross-sectional shape. Two wall surfaces adjacent to the upper hole portion 32a are inclined surfaces 32aa in which a portion below the upper end portion recedes to the outer diameter side. A punching edge in which two adjacent upper end edges different from the two adjacent wall surfaces 32aa in the blade portion entry hole 32 mesh with the punching edge 27 and the cutting edge 30 of the corner cutting punch die 21, respectively. 33 and a cutting edge 34.

  FIG. 5 shows a punching die for punching, and FIG. 6 shows a die for punching. The punching die 41 for punching and the die die 51 for punching are general ones for punching a plate material into a rectangle. The punching die 41 for punching is provided with a blade 43 having a rectangular cross section at the lower end of the handle 42. The lower edge that is each side of the bottom surface 44 of the blade portion 43 is a punching edge 45. In the illustrated example, the center of the front shape of the bottom surface 44 is recessed upward, but the bottom surface 44 may be a horizontal flat surface. The die die 51 for punching has a substantially circular planar shape, and is provided with a slit-like blade portion entry hole 52 through which the blade portion 43 of the punch die 41 enters vertically. The blade entry hole 52 is a stepped hole in which the lower hole 52b is longer in the longitudinal direction than the upper hole 52a, and the blade 43 of the punch die 41 is fitted into the upper hole 52a. The cross-sectional shape is matched. The upper end edge of the blade entry hole 52 is a punching edge 53 that meshes with the punching edge 45 of the punching die 41 for punching.

  The punch dies 1, 21, 41 and the die dies 11, 31, 51 are used by being mounted on a punch press (not shown). The structure of the die mounting portion in the punch press will be described by taking as an example the case where the die is the cut-off cutting die 1 and the cut-off die 11.

  In FIG. 7, the punch cutting die 1 for cut-off is attached to the head member 61 with a set bolt 62, and is fitted to the die installation hole 65 of the upper turret 64 via the punch holder 63 so as to be movable up and down. Yes. The head member 61 is engaged with a ram 66 of a punch driving mechanism (not shown) with its T-shaped head, and is driven up and down. The punch drive mechanism may be a crank type or a hydraulic type. The punch holder 63 is raised and lowered by presser springs 67A and 67B so as to be movable up and down, and a stripper plate 68 is attached to the lower end.

  The post-cutting punch die 1 is an index tool capable of indexing. That is, the mold installation hole 65 is provided in the rotating body 71 that is rotatable with respect to the turret body 64a. The rotating body 71 has a worm wheel 72 on its outer peripheral surface, and a worm gear 74 provided on a rotating shaft 73 disposed in the radial direction of the turret 64 is engaged with the worm wheel 72. By rotating the rotating shaft 73 by the driving means, the rotation is transmitted to the rotating body 71 via the worm gear 74 and the worm wheel 72, and the follow-cut cutting punch die 1 is indexed to a desired angle.

  The die for cutting 11 is also an index tool capable of indexing the angle. That is, the die holder 77 is rotatably mounted on the lower turret 76, and the die for cutting-off cutting 11 is held on the die holder 77. The die holder 77 has a worm wheel 78 on the outer peripheral surface, and a worm gear 80 provided on a rotary shaft 79 arranged in the radial direction of the turret 76 is engaged with the worm wheel 78. By rotating the rotating shaft 79 by the driving means, the rotation is transmitted to the die holder 77 via the worm gear 80 and the worm wheel 78, and the die for cutting 11 is indexed at a desired angle.

  The upper and lower turrets 64 and 76 are mold support members that support various molds for punching at a plurality of locations in the circumferential direction. As one of the installation molds, a punch mold for additional cutting is used. 1 and a die die 11 for additional cutting are installed. The other punch dies 21 and 41 and the die dies 31 and 51 are also provided so as to be able to index the angle in the same manner as described above. The punch press for installing these molds is not limited to the turret type, and the punch mold and the die mold may be installed on a mold support member (not shown) different from the turret. .

  The post-cutting punch die 1 and the die die 11 are used for making a cut on the plate material W to form a long hole longer than the cutting or die width. Further, by using the punch cutting die 1 and the die die 11 in combination with the corner cutting punch die 21 and the die die 31, a rectangular opening can be satisfactorily formed in the plate material. The combination of the post-cutting cutting die 1 and the corner cutting punch die 21 is a post-cutting / corner cutting punch die set. For forming the opening, a punching die 41 for punching and a die die 51 for punching are used in combination.

  Next, a description will be given of a method for forming an opening in a plate material by a punch press using the above-described molds. As shown in FIG. 8A, a case where a rectangular opening 90 is formed in the plate W is taken as an example. This plate material opening forming method is performed in the order of a preliminary opening forming process, a corner cutting process, a follow-up preparation process, a follow-up process, and a punching process.

  In the preliminary opening forming process, as shown in FIG. 8B, a preliminary opening 91 smaller than the opening 90 is formed inside the target opening 90. The dimensional difference S between the target opening 90 and the preliminary opening 91 is set to be slightly narrower than the width of the blade portion 3 of the post-cutting punch die 1. The preliminary opening 91 is formed by, for example, additional cutting using a general punching die such as the punching die 41 for punching and the die die 51 for punching shown in FIGS. According to the follow-up cutting using such a general punching die, a protruding trace remains at the joint portion of the punch hole on the cut surface of the preliminary opening 91, but the peripheral edge of the preliminary opening 91 is not Since it is removed in the process of, there is no problem.

  In the corner cutting process, punching is performed by using the corner cutting punch mold 21 and the die mold 31 at the corners of the opening 90. As shown in FIG. 9A, the down-cut height of the corner cutting punch die 21 is the opposite side of the recess 28a to the punching blade portion 24 on the bottom surface 28 of the cutting blade portion 25 of the punch die 21. The height of the end is set to be the height of the upper surface of the plate material W before processing. Thereby, a corner-shaped corner cut 92 (FIG. 8C) is formed in the plate material W by the punching edge 27 of the punching blade portion 24 and the cutting edge 30 of the cutting blade portion 25 of the punch die 21. The inner portion of the corner cut 92 is pushed downward by the bottom surfaces 26 and 28 of the punching blade portion 24 and the cutting blade portion 25 to form a corner cut piece 93. By setting the height of the punch die 21 to be lowered to the above height, the base end 93a of the corner cut piece 93, that is, the boundary end with the portion where the corner cut 92 is not formed becomes nearly horizontal. .

  FIG. 10A shows an enlarged corner cut 92. The appearance of the corner cut 92 is different between a portion 92 a formed by the punching edge 27 of the cutting blade portion 25 of the punching blade portion 24 and a portion 92 b formed by the cutting edge 30. That is, the portion 92a formed by the punching edge 27 is in a state where the corner cut pieces 93 are completely punched and separated from the main body portion Wa of the plate material W as shown in FIG. However, in the portion 92b formed by the cutting edge 30, as shown in FIG. 10C, the corner cutting piece 93 is not completely punched with respect to the main body portion Wa of the plate material W, and both Wa, 93 Are connected with a step. The size of the step becomes smaller toward the base end side and becomes zero at the base end side. Since the bottom surface 28 of the cutting blade portion 25 has the shape described above, the step gradually decreases in an asymptotic line as it approaches the proximal end. In this way, the corner cut 92 is formed so that the corner cut piece 93 is not completely separated from the main body portion Wa of the plate material W and the step between the both Wa and 93 is gradually reduced. The plate material W is not work hardened in the vicinity of the base end, and there is almost no sagging on the cut surface or the cut surface. Even in the portion 92b formed by the cutting edge 30, the corner cutting piece 93 is completely punched and separated from the main body portion Wa of the plate material W on the side close to the portion 92a formed by the punching edge 27. is doing.

  In the follow-up preparation process, the punching blade part 4 overlaps the corner cutting piece 93 formed in the corner cutting process, and the cutting blade part 5 is positioned farther from the corner than the punching blade part 4. Punching is performed by using the punch cutting die 1 for cut-off arranged in this way and the die die 11 for cut-off cutting arranged in correspondence with the punch die 1 for cut-off cutting. As shown in FIG. 9 (B), the down-cutting height of the punching die 1 for additional cutting is opposite to the punching blade portion 4 of the recess 9a in the bottom surface 9 of the cutting blade portion 5 of the punch die 1. The height of the side end is set to the height of the upper surface of the plate material W before processing. Accordingly, the punching blade 4 punches the tip side of the corner cut piece 93 to open the punch hole 94 (FIG. 8D), and the corner cutting 92 is followed by the cutting edge 10 of the cutting blade 5. A cut-off cut 95 extending to the side away from the corner is formed, and the inner portion of the cut-off cut 95 is pushed downward by the bottom surface 9 of the cutting blade 5 to form a tongue-like cut-off cut piece 96. As described above, since work hardening has not occurred in the vicinity of the base end of the corner cut 92 formed in the corner cutting process, the additional cutting is performed using the punch die 1 for the additional cutting in the additional cutting preparation process. When this is done, the same sagging occurs at the joint between the corner cut 92 by the corner cutting punch 31 and the additional cut 95 by the additional cutting punch 1 as well as traces on the joint. There is hardly any remaining.

  In addition, if the bottom surface 9 of the cutting blade portion 5 of the punching die 1 for additional cut is a shape that extends at the same height following the opposite end of the concave portion 9a to the punching blade portion 4, the plate material W When the thickness of the sheet is slightly thicker than the specified value due to an error or the like, the portion extending with the same height presses the plate material W and deforms. However, as in this embodiment, the above situation can be avoided if the portion following the opposite end of the concave portion 9a with respect to the punching blade portion 4 is the inclined portion 9c. Moreover, since the recessed part 9a and the slope part 9c are smoothly connected via the curved-surface part 9e, the stress which generate | occur | produces in the board | plate material W with the cutting blade part 5 of the punch die 1 for additional cut is applied to the surface of the board | plate material W. The state can be changed continuously along. That is, the boundary points between the range where the stress is applied and the range where the stress is not applied are not concentrated. Thereby, it can prevent that the board | plate material W deform | transforms into shapes other than the defined shape.

  FIG. 11A shows the additional cut 95 in an enlarged manner. The appearance of the additional cut 95 is different between a portion 95a formed on the cutting edge 10 of the cutting blade portion 5 on the side close to the punching blade portion 4 and a portion 95b formed on the far side. That is, the portion 95a formed on the side close to the punching blade portion 4 is separated by the punching cut piece 96 being completely punched with respect to the main body portion Wa of the plate W as shown in FIG. Although it is in a state, the portion 95b formed on the side far from the punching blade portion 4 has the additional cut piece 96 completely with respect to the main body portion Wa of the plate material W as shown in FIG. It is not punched, and both Wa and 96 are connected with a step. The size of the step is smaller toward the base end side and becomes zero at the base end. Since the bottom surface 9 of the cutting blade portion 5 has the shape described above, the step gradually decreases asymptotically as it approaches the proximal end. In this way, the additional cutting 95 is formed so that the level difference between the two Wa and 96 is gradually reduced without completely separating the additional cutting 96 from the main body portion Wa of the plate material W. The plate material W is not work-hardened in the vicinity of the base end of the cut 95, and the cut surface and the cut surface are hardly sagged.

  Following the follow-up preparation process, the follow-up process is repeated a plurality of times while shifting the position along the cutting line that is the inner edge of the target opening 90. In the cut-off process, the punch die 1 for cut-off cutting is overlapped with the cut-off cutting piece 96 formed by the punching blade portion 4 in the cut-off preparation process or the previous cut-off process, and the cutting blade The part 5 is arranged so as to be positioned farther from the corner than the punching blade part 4 and punching is performed. The operation state of this additional cutting process matches that obtained by replacing the corner cut piece 93 with the additional cut piece 96 in FIG. The down-cutting height of the punching die 1 for the cut-off cutting is such that the height of the opposite end to the punching blade portion 4 of the recess 9a on the bottom surface 9 of the cutting blade portion 5 of the punch die 1 is the same as that before processing. The height of the upper surface of the plate material W is set.

  By this overcutting process, the punching blade portion 4 punches the tip side portion of the additional cutting piece 96 to open a punch hole 94, and the cutting edge 10 of the cutting blade portion 5 makes a previous overcutting cut 95. Subsequently, a new additional cut 95 extending to the side away from the corner is formed, and the inner portion of the additional cut 95 is pushed downward by the lower surface 9 of the cutting blade portion 5 to form a new additional cut 96. To do. As described above, since work hardening has not occurred in the vicinity of the base end of the cut-off cut 95 formed in the cut-off preparation process or the previous cut-off process, a punch die for cut-off cutting in the cut-off process. 1 is used, the same sagging occurs at the joint portion between the previously formed cut-in cut 95 and the cut-in cut 95 formed this time as well as on both sides. Little remains.

  If the cut-off process has proceeded to the center between two adjacent corners, the corner cutting process, the cut-off preparation process, and the cut-off process are performed in reverse from the opposite corner. FIG. 9C shows the state of the follow-up process. Then, as shown in the perspective view of FIG. 12, an uncut portion 97 is left at the center. Both sides of the uncut portion 97 are a pair of additional cut pieces 96 formed by the additional cutting process performed at the end in both directions. The same process is performed for the remaining three sides (FIG. 8E). The punch dies 1, 21, 41 and the die dies 11, 31, 51 are index tools capable of indexing the angle. Therefore, without changing the direction of the plate material W, the above corner cutting process and additional cutting are performed on each side. The preparation process and the follow-up process can be performed.

  Finally, as shown in FIG. 9D, the uncut portion 97 and the pair of additional cut pieces 96 are punched using the punching punch die 41 and the die die 51 in the punching process. . Since work hardening has not occurred in the vicinity of the base end of the additional cut 95 formed in the final additional cut process, when the uncut portion 97 is punched with the punching die 41 for punching, The same sagging occurs at the joints with the punch holes (not shown) formed by the punching die 41 for punching, so that almost no trace remains on the joints. As a result, as shown in FIG. 8F, a clean opening 90 with a smooth inner periphery is formed.

  The blade portion 3 of the post-cutting cutting die 1 may have a constant thickness from top to bottom, but as shown in FIG. 13, the blade portion 3 may have a shape in which the thickness increases toward the bottom. In the figure, the change in thickness is emphasized, but the actual change in thickness is slight.

  The punching die 1 for the cut-off cutting in the illustrated example has the cutting edges 10 formed on both side surfaces along the cutting-off direction of the cutting blade portion 5, but the preliminary opening 91 is previously provided as in the illustrated opening forming method. In the case of forming the cutting edge 10, the cutting edge 10 may be formed only on one side surface of the cutting blade portion 5.

  Further, the punching die 1 for additional cutting in the illustrated example is for performing additional cutting along a linear cutting line, and is along the additional cutting direction of the punching blade portion 4 and the cutting blade portion 5. Although the side surface is a flat surface, the side surface of the punching blade portion 4 and the cutting blade portion 5 along the additional cutting direction is arcuate as in the punch die 1 ′ for additional cutting shown in FIG. If it is a curved surface, it can be cut along the arcuate cutting line.

DESCRIPTION OF SYMBOLS 1,1 '... Punching die 4 for additional cutting 4 ... Punching blade part 5 ... Cutting blade part 8 ... Punching edge 9 ... Bottom face 9a of cutting blade part ... Concave part 9b, 9c ... The part following both sides of a concave part 9d, 9e ... curved surface portion 10 ... cutting edge 21 ... corner cutting punch mold 24 ... punching blade portion 25 ... cutting blade portion 28 ... bottom surface 28a of the cutting blade portion ... concave portions 28b, 28c ... slope portion 28d, 28e ... curved surface portion 90 ... opening 92 ... corner cut 93 ... corner cut piece 94 ... punch hole 95 ... follow-cut cut 96 ... cut-cut piece 97 ... uncut portion W ... plate material

Claims (5)

It is a punch die for additional cut of a punch press for cutting along a continuous cutting line by performing additional cutting on a plate material,
Arranged side by side in the cut-off direction, each of which has a punching blade portion and a cutting blade portion whose side surfaces are located on the same surface and whose lower end edge is a punching edge and a cutting edge,
The punching blade portion protrudes with a step below the cutting blade portion,
The cutting blade portion is inclined upward as the bottom surface moves away from the punching blade portion, and an intermediate portion in the arrangement direction of the punching blade portion and the cutting blade portion on the bottom surface is recessed upward. The contour line of the side surface shape of the recess is a shape in which the inclination angle with respect to the horizontal decreases as the distance from the punching blade portion increases.
Punch die for additional cut of punch press.   2. The punch press follower according to claim 1, wherein the concave portions on the bottom surface of the cutting blade portions are smoothly connected to the slope portions continuing on both sides in the alignment direction via downwardly convex curved portions. Punch die for cutting and cutting. A punch die for cutting a corner of a punch press for cutting a plate material along a predetermined corner shape,
A punching blade portion whose lower edge on the outer surface is a punching edge that follows the corner shape, and a cutting edge that extends in the extending direction of the punching edge in a planar shape with the lower edge on one side continuing to both ends of the punching edge. Having two cutting blades which are made into a cutting edge,
The punching blade portion protrudes downward from the cutting blade portion,
The cutting blade portion is inclined upward as the bottom surface moves away from the punching blade portion, and an intermediate portion in the arrangement direction of the punching blade portion and the cutting blade portion on the bottom surface is recessed upward. The contour line of the side surface shape of this recess is a shape in which the inclination angle with respect to the horizontal decreases as the distance from the punching blade portion increases.
Punch die for corner cutting of punch press. A die set comprising the punch die for additional cutting of the punch press according to claim 1 and the corner punching die for corner cutting of the punch press,
The corner cutting punch mold is
A punching blade portion having a punching edge along a corner shape with a lower end edge of the outer side surface, and a lower end edge of one side surface extending to both ends of the punching edge in a planar shape in the extending direction of the punching edge Two cutting blades that are extended cutting edges,
The punching blade portion protrudes downward from the cutting blade portion,
The cutting blade portion is inclined upward as the bottom surface moves away from the punching blade portion, and an intermediate portion in the arrangement direction of the punching blade portion and the cutting blade portion on the bottom surface is recessed upward. The contour line of the side surface shape of this recess is a shape in which the inclination angle with respect to the horizontal decreases as the distance from the punching blade portion increases.
Punch mold assembly for punch cutting and corner cutting of punch presses. A method for forming an opening of a plate material by a punch press using the punch die for additional cutting according to claim 1 or 2, and the punch die for corner cutting according to claim 3. Including cutting preparation process, additional cutting process, and punching process,
In the corner cutting process, punching is performed using the punch die for corner cutting at a location that becomes a corner of an opening to be formed in the plate material, and the punching blade portion and the cutting blade portion of the punch die are used to form the plate material. It is a process of forming a corner cut and pushing down the inner part of the corner cut downward to make a corner cut piece,
In the additional cutting preparation process, the punching blade portion of the punching die for additional cutting is vertically overlapped with the corner cut piece, and the cutting blade portion of the punch die is cut from the corner more than the punching blade portion. Punching is performed using the punch die for additional cutting that is disposed so as to be located apart, and the corner cut piece is punched by the punching blade portion of the punch die, and the punch die is cut The blade portion is a process of forming a follow-up cut extending to the side away from the corner following the corner cut, and pressing down the inner part of the cut-off to make a cut-off cut piece,
The additional cutting process is repeated a plurality of times following the additional cutting preparation process, and the additional cutting punch die is applied to the additional cutting piece formed in the additional cutting preparation process or the previous additional cutting process. Punching is performed using the punch die for additional cutting, which is arranged so that the punching blades overlap each other and the cutting blade of the punch die is located farther from the corner than the punching blade. The punching blade portion of the punch die cuts out the additional cutting piece, and the cutting blade portion of the punch die cuts out a new additional cutting cut extending from the corner to the side away from the corner. Is formed, and the inner portion of the additional cut is pushed downward to form a new additional cut piece,
The punching process is performed by sequentially performing the corner cutting process, the additional cut preparation process, and the additional cut process from the two adjacent corners toward the center between the two corners, and the final cut process performed in both directions. It is a punching process in which the uncut portions formed respectively are punched using a punching die other than the punching die for additional cutting and the punching die for corner cutting.
A method for forming openings in plate materials.

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