JP2015051462A - Punch for punching sheet metal and sheet metal punching device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a punch for punching a sheet metal and a sheet metal punching device using the same, excellent in durability, in which a through-hole can be formed in an accurate position in addition without burr and which is free from a risk of settling of a projection even after long time use.SOLUTION: A sheet metal punching device 1 includes: an upper die holder 2 which is lifted and lowered with a hydraulic ram or the like; a pressing plate 3 which is fixed to the upper die holder 2; a pressing pad 5 which is hung down from the upper die holder 2 through an elastic member 4; a punch holder 7 which is fixed to the pressing pad 5; a lower die 9 on which a sheet metal 8 to which punching processing is applied is mounted; and a die 10 which is embedded in the lower die 9.

Description

  The present invention relates to a punch for punching a thin metal plate, and a punching device for a thin metal plate provided with a die that uses this punch and has a hole into which the punch is inserted.

  A punch having a cylindrical body having an outer diameter smaller than the hole diameter of the die and a conical protrusion on one end surface of the cylindrical body is pressed against the thin metal plate, and a punch hole is formed in the thin metal plate to form a through hole. With the protrusion inserted into the die, the movement of the sheet metal is restricted, and the punch is further inserted into the hole of the die, whereby the sheet metal is pulled and broken around one end surface of the cylindrical body of the punch, and has the same diameter as the hole of the die. There has been proposed a drilling device in which a through hole is formed in a thin metal plate (see Patent Documents 1 to 3).

JP 2008-80350 A JP 2008-155216 A JP 2008-290088 A

  Incidentally, the punch for punching a thin metal plate described in Patent Document 3 includes a cylindrical punch body and a protrusion integrally provided on one end surface of the punch body. A cylindrical part integrally provided on one end surface of the punch body, a conical part integrally provided on the cylindrical part, and an elastically deformable surrounding the cylindrical part excluding the conical part Because of this, even when the diameter of the hole to be drilled is small, stress can be concentrated on the sheet metal at the tip of the corner that defines the hole of the die, and the corner that defines the hole of the die In this punch, it is possible to form a through-hole by cutting a thin metal sheet, and it is possible to form a through-hole at an accurate position without burrs. The above effect can be obtained by using the protrusions Ku, optionally, compelled to perform punch-exchange, especially in the case of punching the sheet metal of approximately 1mm above thickness, there is a fear that such problems can often occur.

  The present invention has been made in view of the above-mentioned points. The object of the present invention is to be able to form a through-hole at an accurate position without burrs, and to prevent protrusions even after long-term use. An object of the present invention is to provide a punch for punching a thin metal plate having no risk of sag and having excellent durability and a punching device for a thin metal plate using the punch.

  The punch for punching a thin metal plate of the present invention has a columnar punch body, and an outer edge that is concentric with the center of the outer edge of the end face and has a diameter smaller than the diameter of the outer edge on one end face of the punch body. A conical protrusion integrally provided with a bottom surface having a conical portion having a vertex on a central axis passing through the center of the outer edge of the end surface, and the conical protrusion. And a frustoconical portion having a vertex on a central axis passing through the center of the outer edge of the end surface, and the conical portion is a portion of the frustoconical portion. The apex angle is larger than the apex angle.

  According to such a punch for punching a thin metal plate, a bottom surface having an outer edge that is concentric with the center of the outer edge of the end surface and has a diameter smaller than the diameter of the outer edge is integrally formed on one end surface of the punch body. Since it has a conical projection provided, it can open a hole in the sheet metal by the projection, and the movement of the sheet metal can be controlled by the projection inserted in the hole, so that there is no burr and accurate position In addition, a conical protrusion is formed integrally with the truncated cone portion and the truncated cone portion, and has an apex angle larger than the apex angle of the truncated cone portion. Since the conical section is formed, it is possible to prevent not only the conical section that forms the piercing hole in advance but also the fringed section of the conical section. Can eliminate the risk of protrusions and improve durability Rukoto can.

  In a preferred example, the apex angle of the cone is 70 ° to 90 °, the apex angle of the truncated cone is 20 ° to 30 °, and as an example, the height of the conical protrusion is from 1 mm. The height of the conical part is 0.3 mm to 3 mm, and the diameter of the outer edge of the end face is 1 mm to 25 mm, 1 mm to 10 mm, or 1 mm to 5 mm.

  The punch for punching a thin metal plate according to the present invention has a punched hole in a thin metal plate corresponding to the hole of the die by a conical protrusion on the thin metal plate disposed on one surface of the die having a hole, The sheet metal is pulled and broken around one end surface of the punch body by further inserting the punch into the hole of the die with the protrusion inserted into the piercing hole restricting the movement of the sheet metal relative to the die. A through-hole is formed on the surface.

  In a preferred example, the punch body is cylindrical and the outer edge of one end surface of the punch body is circular, but the punch body is a polygonal column including a triangular prism, and the outer edge of one end surface of the punch body is A polygonal shape including a triangular shape may be used. Alternatively, the punch body may have an elliptical columnar shape, and the outer edge of one end surface of the punch body may have an elliptical shape. As described above, the punch body and the outer edge of the end surface thereof may have various shapes in relation to the through-hole to be formed, and are cylindrical, polygonal, elliptical, circular, polygonal, and elliptical. However, other shapes may be used in relation to the through-hole to be formed.

  In the present invention, the diameter of the outer edge of one end face of the punch body is the diameter when the outer edge is circular, and the outer edge is a polygonal shape including a triangular shape or an elliptical shape. The diameter of a virtual circle in which the outer edge of these shapes is inscribed, and the center of the outer edge is also the center when the outer edge is circular, and the outer edge is a polygonal or elliptical shape including a triangular shape Is the center of the virtual circle.

  In the present invention, the tip of the conical portion may be pointed or slightly rounded, and the outer surface of the conical portion and the outer surface of the truncated conical portion have no corners and are smoothly continuous. However, the present invention is not limited to this, and the corner portions may be connected.

  The outer edge of one end face of the punch body may not be chamfered, but preferably 0.3 mm in order to reduce the effect of shear that causes burrs and to better pull and break the sheet metal. And chamfered with a radius of curvature R of 3 mm.

  A sheet metal drilling device of the present invention comprises the above-described punch for punching a sheet metal and a die having a hole into which the punch is inserted, and a piercing hole is formed in the sheet metal by a protrusion. The movement of the sheet metal is restricted by the protrusion inserted into the piercing hole, and then the sheet metal is broken around one end surface of the punch body to form a through hole in the sheet metal.

  The sheet metal drilling device according to the present invention first forms a piercing hole in the sheet metal by the protrusion, restricts the movement of the sheet metal by the protrusion inserted into the piercing hole, and then the one of the end surfaces of the punch body. The thin metal plate is broken around to form a through hole in the thin metal plate.In the present invention, in the case of such a punch, when the whole of the punch is composed of a simple conical protrusion for forming a through hole. Is the result that it becomes impossible to obtain sufficient strength at the tip of the cone-shaped protrusion, resulting in bending or breakage of the tip of the protrusion, resulting in bending or breakage of the whole, and frequent replacement is required. It is based on.

  The hole of the die is usually a circular hole when the punch body is cylindrical and the outer edge of one end surface thereof is circular, but the punch body is not cylindrical and the end surface of one end face thereof is When the outer edge is also other than a circular shape, it preferably has a shape corresponding to the shape of the outer edge of the punch body and its end face.

  When the thickness of the sheet metal to be punched is t, the difference f as the clearance of the punch body with respect to the die hole, that is, the difference f between the radius of the outer edge of one end surface and the radius of the die hole is 0.15 t or more. However, it is preferably 2 mm or less.

  The sheet metal drilled by the drilling device of the present invention has a thickness of about 0.4 mm to 2.0 mm in order to obtain good results, but in order to obtain better results, The plate thickness is about 0.6 mm to 1.6 mm.

  An example of a sheet metal drilling device according to the present invention is arranged in a case, a slider that is slidably mounted in the case in the vertical direction, and in which a punch is movably moved in the vertical direction. And a return means for elastically urging the punch and slider upward to return the punch and slider to the initial position. In such an example, the punch is moved in the vertical direction. A sliding guide member provided on the case may be further provided.

  The slider is provided with a recess, and is preferably engaged with a retaining pin fixed to the case in the recess so that the slider does not come out of the case due to the elastic force of the return means. The coil spring is preferably provided, but the present invention is not limited to this, and other elastic members may be used.

  According to the present invention, a through-hole can be formed at an accurate position without burrs, and there is no risk of protrusion sag even with long-term use. Can be provided, and a sheet metal drilling device using the punch can be provided.

FIG. 1 is a cross-sectional view of a preferred example of an embodiment of the present invention. FIG. 2 is an explanatory side view of a part of the punch used in the example shown in FIG. FIG. 3 is a front view of the punch shown in FIG. FIG. 4 is an explanatory diagram of the punch and the die used in the example shown in FIG. FIG. 5 is an operation explanatory diagram of the example shown in FIG. FIG. 6 is an operation explanatory diagram of the example shown in FIG. FIG. 7 is a diagram for explaining the operation of the example shown in FIG. FIG. 8 is a diagram for explaining the operation of the example shown in FIG.

  Next, the present invention will be described in more detail based on an example of a preferred embodiment shown in the drawings. The present invention is not limited to these examples.

  1 to 5, the sheet metal drilling device 1 of this example includes an upper mold holder 2 that is lifted and lowered by a hydraulic ram, a pressing plate 3 fixed to the upper mold holder 2, and an upper mold holder 2. A pressing pad 5 suspended through an elastic member 4, a punch holder 7 configured as a punch unit fixed to the pressing pad 5 with a bolt 6 or the like, and a sheet metal 8 to be punched Is mounted, and a die 10 embedded in the lower mold 9 is provided.

  The punch holder 7 includes a cylindrical case 11 fixed to the pressing pad 5 with a bolt 6 or the like, a cylindrical slider 12 mounted on the case 11 so as to be slidable in the vertical direction, and an inside of the slider 12. A punch 13 for punching a thin metal plate accommodated movably in the vertical direction, and a punch that is arranged in the slider 12 and elastically biases the slider 12 upward via the punch 13 and the punch 13. 13 and a return means having a coil spring 14 for returning the slider 12 to the initial position, and a sliding guide member 15 provided in the case 11 so as to guide the vertical movement of the punch 13.

  The slider 12 includes a recess 22, and engages with the retaining pin 21 fixed to the case 11 at the recess 22 so that the slider 12 does not slip out of the case 11 due to the elastic force of the coil spring 14. The upper plate holder 2 is pressed downward by the pressing plate 3 when the upper die holder 2 is lowered.

  The punch 13 has a cylindrical punch body 25 and a diameter d1 as a diameter of the outer edge 27 that is concentric with a center O of a circular outer edge 27 chamfered on the end face 26 on one end face 26 of the punch body 25. A conical protrusion 30 provided integrally with the bottom surface 29 having a bottom surface 29 having a circular outer edge 28 having a smaller diameter d2 and a circular end surface 31 at the other end of the punch body 25 are integrated. And a collar portion 32 provided on the head.

  In the punch 13, the protrusion 30 has a conical portion 37 having a vertex 36 on a central axis 35 passing through the center O of the outer edge 27 of the end face 26 and having an apex angle θ1 of 70 ° to 90 °, and a diameter d2. An apex 39 is formed on a central axis 35 formed integrally with the bottom surface 38 of the conical portion 37 having a smaller diameter d3 and passing through the bottom surface 29 having the outer edge 28 and the center O of the outer edge 27 of the end surface 26. And a truncated cone part 40 having an apex angle θ2 of 20 ° to 30 ° smaller than the apex angle of the conical part 37.

  The height h1 of the protrusion 30 is 1 mm to 6 mm, the height h2 of the conical part is 0.3 mm to 3 mm, and the diameter d1 of the outer edge 27 of the end face 26 is 1 mm to 25 mm, 1 mm to 10 mm, or The outer edge 27 of the end face 26 is chamfered with a radius of curvature R of 0.3 mm to 3 mm.

  The coil spring 14 is in contact with the flange portion 32 at one end and the flange portion 41 of the sliding guide member 15 at the other end. The sliding guide member 15 is integrated with the flange portion 41 in addition to the flange portion 41 and the case 11. The hole 42 has a cylindrical portion 43 fitted to the case 11, and the lower end portion of the punch body 25 of the punch 13 is slidably guided and supported on the inner peripheral surface of the cylindrical portion 43.

  The die 10 is a circular hole 51 that is a large hole into which the punch main body 25 of the punch 13 is inserted, and a small hole that is connected to the circular hole 51 via an inclined step surface 52, and is punch scraps 63 (FIG. 6 to FIG. 6). 8) and a circular hole 53 that is continuous with the circular hole 53 and has a diameter larger than that of the circular hole 51 and the circular hole 53. In addition to the inclined step surface 52, the die 10 has an inner peripheral surface 56 that defines the outer edge 55 of the circular hole 51, and an outer edge 57 of the circular hole 53. And an inner peripheral surface 60 that defines an outer edge 59 of the circular hole 54.

  When the thickness of the sheet metal 8 to be punched is t, the difference (clearance) f between the radius 1/2 · d1 of the outer edge 27 of the end face 26 and the radius 1/2 · D1 of the circular hole 51 of the die 10 is 0.15 t. It is above and is 2 mm or less.

  The circular hole 53 connected to the circular hole 51 via the inclined stepped portion surface 52 is smaller than the diameter D1 of the circular outer edge 55 itself of the circular hole 51, while being larger than the diameter d1 of the outer edge 27 itself of the end surface 26. An angle θ3 between 135 ° and less than 180 ° with respect to the inner peripheral surface 56 of the die 10 which has a large diameter D2 and is interposed between the circular hole 51 and the circular hole 53 and which defines the circular hole 51. The inclined step surface 52 that is inclined with a diameter has a diameter that gradually decreases from the circular hole 51 toward the circular hole 53, and in this example, has a diameter that gradually decreases.

  In the drilling device 1 described above, when the pressing plate 3, the pressing pad 5 and the punch holder 7 are lowered as the upper die holder 2 is lowered, the thin metal plate 8 placed on the lower die 9 is pressed by the pressing pad 5. 6 is sandwiched and fixed between the lower die 9 and the pressing pad 5 and the slider 12 is pressed by the pressing plate 3, and the punch 13 is lowered when the slider 12 is pressed. As described above, the piercing hole 61 is opened in the thin metal plate 8 by the protrusion 30, and the punch 13 is further lowered while the movement of the thin metal plate 8 is restricted by the protrusion 30 inserted into the piercing hole 61, and the circular hole 51 of the die 10. When the punch body 25 of the punch 13 is inserted with its end face 26 leading, the sheet metal 8 is broken around the end face 26 of the punch body 25 as shown in FIG. Formed On the other hand, the punch scraps 63 having the piercing hole 61 through which the protrusion 30 has passed are lowered toward the circular hole 53 as the punch 13 is lowered, and after the through hole 62 is formed, the punch 13 is further lowered to the circular hole 53. When inserted, as shown in FIG. 8, the annular outer edge portion 64 of the punch scrap 63 is guided by the inclined step portion surface 52 and is gradually squeezed, and the outer edge portion 64 passes through the inclined step portion surface 52 and becomes the outer edge. When the portion 64 is completely squeezed, the lowering of the punch 13 is stopped, and conversely, the punch 13 is raised, and the punch 13 moves away from the punch debris 63 and the punch debris 63 rises. And is stacked and held on the punch scraps 63 already held without contacting the inner peripheral surface 58 at the outer edge portion 64 and inclining with respect to the die 10 in the circular hole 53. On the other hand, the upper mold holder 2 The punch 13 which has been lifted completely as it is lifted is then lowered again in order to form the next through hole 62 of the sheet metal 8 which is newly sandwiched and fixed between the lower die 9 and the pressing pad 5. Then, the above operation is repeated, and the punch scraps 63 stacked and held in the circular hole 53 are gradually pushed out from the preceding one to the circular hole 54 through the circular hole 54 to the outside of the die 10. It is supposed to be discharged.

  When the punch body 25 of the punch 13 is inserted into the circular hole 53 arranged between the circular hole 51 and the circular hole 54 and the punch scraps 63 are discharged through the circular hole 53, the punch hole 63 is generated after the through hole 62 is formed. Since the punch scrap 63 can be held by the circular hole 53, for example, even if the circular hole 51, the circular hole 54, and the circular hole 53 are arranged obliquely or horizontally, in other words, the punch 13 is moved obliquely or horizontally. Even if the through-hole 62 is formed obliquely or horizontally, the disadvantage that the punch scraps 63 fall down at the circular hole 53 and cannot be discharged from the circular hole 53 can be eliminated, and the thin metal 8 supplied one after another is removed. The through holes 62 can be formed continuously.

  According to the punching device 1, the inclined stepped surface 52 interposed between the circular hole 51 and the circular hole 53 has a diameter that gradually decreases from the circular hole 51 to the circular hole 53. When the punch scraps 63 are pushed into the circular holes 53 by the punch main body 25, it is possible to avoid tensile breakage or shearing by the punch main body 25 and the inclined stepped surface 52 of the outer edge portion 64 of the punch scraps 63, and the secondary punch scraps in the form of threads. Can be eliminated, the continuous operation can be interrupted, and the possibility that a desired through hole cannot be formed can be eliminated.

  In the punch 13, a bottom surface 29 having an outer edge 28 that is concentric with the center O of the outer edge 27 of the end surface 26 and has a diameter d 2 smaller than the diameter d 1 of the outer edge 27 is formed on one end surface 26 of the punch body 25. Since the conical protrusion 30 provided integrally is provided, the piercing hole 61 is opened by the protrusion 30 in the thin metal plate 8, and the movement of the thin metal plate 8 can be restricted by the protrusion 30 inserted into the piercing hole 61. As a result, the through-hole 62 can be formed at an accurate position without burrs, and the conical protrusion 30 is provided integrally with the truncated cone portion 40 and the top of the truncated cone portion 40. Since the conical portion 37 having the apex angle θ1 larger than the angle θ2 is provided, the conical portion 37 that precedes the piercing hole 61 can be prevented from being sag, and the conical portion 37 is prevented from being deflated. Results that can be prevented, 截The head cone portion 40 can be prevented from sagging, and the possibility of sag of the projection 30 can be eliminated even after long-term use, and the durability can be improved.

  Moreover, since the outer edge 27 of the end face 26 is chamfered with a curvature radius R of 0.3 mm to 3 mm, the thin metal 8 can be pulled and broken more favorably by reducing the shearing effect that causes burrs. In addition, since the difference f is 0.15 t or more, the through-hole 62 can be effectively formed in the thin metal plate 8 by causing mainly tensile fracture in addition to some shearing.

  In the punching device 1, the punch 13 is moved up and down to form the through hole 62. However, the punch 13 may be moved obliquely to form the through hole 62 in the inclined portion of the thin metal plate 8.

  In the punching device 1 described above, the punch body 25 has a cylindrical shape, and the hole of the die 10 is also a circular hole 51 corresponding to the shape of the punch body 25. Instead, the punch body 25 has a regular quadrangular prism shape. The outer edge 27 of the end face 26 of the punch body 25 may be a regular quadrangle (square), a quadrangle (rectangle), or an ellipse. In this case, as the die 10, The hole is a regular square (square), square (rectangular) or elliptical hole 51 corresponding to the shape of the punch body 25.

DESCRIPTION OF SYMBOLS 1 Drilling device 2 Upper mold holder 3 Pressing plate 4 Elastic member 5 Pressing pad 6 Bolt 7 Punch holder 8 Sheet metal 9 Lower mold 10 Die 13 Punch 25 Punch main body 26 End surface 27, 28 Outer edge 29 Bottom surface 30 Projection 36 Vertex 37 Conical part 38 bottom 39 vertex 40 truncated cone

Claims (5)

  A columnar punch body and a conical shape provided integrally with a bottom surface having an outer edge concentric with the center of the outer edge of the end face and having a diameter smaller than the diameter of the outer edge on one end face of the punch body The cone-shaped protrusion is formed integrally with a conical portion having a vertex on a central axis passing through the center of the outer edge of the end surface, and a bottom surface of the conical portion. A frustoconical portion having a vertex on a central axis passing through the center of the outer edge of the end face, and the conical portion has an apex angle larger than the apex angle of the frustoconical portion. Punch for thin metal drilling.   The punch for punching a thin metal plate according to claim 1, wherein the apex angle of the conical portion is 70 ° to 90 °.   The punch for punching a thin metal plate according to claim 1 or 2, wherein the vertex angle of the truncated conical portion is 20 ° to 30 °.   A sheet metal placed on one surface of a die having a hole is pierced by a conical protrusion in a sheet metal portion corresponding to the hole of the die, and a protrusion inserted into the hole is formed with respect to the die. Further, by inserting the punch into the hole of the die while restricting the movement of the sheet metal, the sheet metal is pulled and broken around one end surface of the punch body to form a through hole in the sheet metal. Item 4. A punch for punching a thin metal plate according to any one of Items 1 to 3.   A punch for punching a thin metal plate according to any one of claims 1 to 4 and a die having a hole into which the punch is inserted, and a piercing hole is formed in the thin metal plate by a protrusion. The sheet metal is configured to restrict the movement of the sheet metal with the protrusion inserted into the piercing hole, and then to break the sheet metal around one end surface of the punch body to form a through hole in the sheet metal. Drilling device.

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