Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D28/00—Shaping by press-cutting; Perforating
  • B21D28/24—Perforating, i.e. punching holes
  • B21D28/28—Perforating, i.e. punching holes in tubes or other hollow bodies
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
  • B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
  • B26F1/02—Perforating by punching, e.g. with relatively-reciprocating punch and bed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B26—HAND CUTTING TOOLS; CUTTING; SEVERING
  • B26F—PERFORATING; PUNCHING; CUTTING-OUT; STAMPING-OUT; SEVERING BY MEANS OTHER THAN CUTTING
  • B26F1/00—Perforating; Punching; Cutting-out; Stamping-out; Apparatus therefor
  • B26F1/02—Perforating by punching, e.g. with relatively-reciprocating punch and bed
  • B26F1/14—Punching tools; Punching dies

Definitions

• the present invention relates to a method of the kind defined in the preamble of Claim 1, and according to a second aspect to a punch die for use when carrying out the method.
• Holes can normally be punched in a workpiece with no difficulty, provided that the holes shall be punched through a part of the workpiece where both sides of said are freely accessible from outside the workpiece, for instance when holes are to be punched in sheet material.
• the sheet, plate or strip is then laid against a fixed support surface that includes punch cavities and a punch-carrying tool is positioned with the punches opposite the punch cavities and pressed down against the sheet and therewith punch-out the holes .
• the insertion of a die between the two walls of the workpiece provides an anvil means which fills out the space between said walls and provides support for the wall as it is met by the punch.
• the anvil means enables the hole or holes to be punched without deforming the wall.
• the method can be applied for punching-out a single hole, it is primarily advantageous for use when punching-out a plurality of holes simultaneously in the wall of the workpiece. This constitutes a preferred embodiment of the inventive method.
• punching of the holes is carried out in two stages, wherein the holes are punched in the second wall after having removed the die.
• the punches move down through the holes made in the first wall.
• the aforesaid object is achieved with a punch die constructed in accordance with Claim 4.
• the inventive die enables the inventive method to be carried out.
• Fig. 1 is a perspective view of a workpiece in which holes have been punched in accordance with the invention
• Fig. 2 illustrates the problem addressed by the present invention
• Fig. 3 is a cross-sectional view of a workpiece and illustrates a first step of an inventive method
• Fig. 4 is a cross-sectional view corresponding to Fig. 3 and illustrating a second step of an inventive method
• Fig. 5 is a sectional view of the workpiece shown in Fig. 3, taken perpendicular to the section in Fig. 3;
• Fig. 6 illustrates a measure taken between the steps illustrated in Figs. 3 and 4.
• Shown in Fig. 1 is a workpiece 1 in the form of a two-wall elongated strip having a bottom wall 2 and a top wall 3 in which respective rows of holes 10, 4 have been punched.
• the illustrated workpiece may be made of aluminium, for instance.
• Fig. 2 illustrates the difficulty of punching holes in such a workpiece. If the workpiece is simply clamped to the work table of the punching machine, the upper wall 3 will not be supported and the punch 5 will deform the wall 3 as it punches holes therein. The disc punched from the workpiece will remain on the bottom wall and present an obstacle to continued punching.
• Figs. 3 and 5 illustrate the manner in which holes are punched in the upper wall 3 of the workpiece 1 in accordance with the invention.
• a die 8 is inserted in the space between the two walls 2, 3, so as to support the upper wall 3.
• the upper side of the die 8 is provided with punch cavities 7a,
• the die is positioned so that the punch cavities are located centrally of respective punches 5a, 5b etc.
• the die thus functions as an effective anvil means, therewith enabling the holes 4 to be punched readily in the upper wall
• the length of stroke of the punches must be limited in the first punching operation, so that the discs punched from the workpiece will not be pressed firmly into the die cavities and become fixed therein.
• the die 8 is withdrawn form the workpiece 1 in the direction of the arrow A shown in Fig. 6. Holes can now be punched in the bottom wall, wherewith a punch moves down through a respective hole that has already been punched in the upper wall 3.
• the discs punched from the holes 7a, 7b etc. are removed from the die 8, for instance with the aid of compressed air, and the die 8 then inserted into the new workpiece .
• Withdrawal and insertion of the die 8 may, of course, be controlled automatically or effected purely manually.
• a punch die that is common for all holes to be punched in the upper wall 3. It is also conceivable, however, to use two (or more) shorter units and to insert a die into the workpiece from each direction.
• the invention is primarily conceived for punching holes in a workpiece of the illustrated appearance, it will be apparent that the invention can also be applied with work- pieces that have lateral extensions in two directions where the holes are distributed over one surface instead of along a strip.
• the invention can also be applied in respect of work- pieces in which only one hole shall be punched in its upper wall, and in respect of workpieces where holes shall be punched solely in one of the two walls.
• the illustrated example can be readily modified for use when the two walls are angled to one another, i.e. not parallel. Neither is the inventive method restricted to square profiles, but can also be applied to U-profiles or to a double-wall workpiece in which the two walls are joined together solely at certain places .

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Forests & Forestry (AREA)
• Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
• Punching Or Piercing (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20407268

Family Applications (1)

Country Status (7)

Cited By (1)

Citations (5)

• 1997
  • 1997-06-05 SE SE9702153A patent/SE512912C2/sv not_active IP Right Cessation
• 1998
  • 1998-06-02 AU AU80463/98A patent/AU8046398A/en not_active Abandoned
  • 1998-06-02 WO PCT/SE1998/001044 patent/WO1998055244A1/en active IP Right Grant
  • 1998-06-02 AT AT98928737T patent/ATE233138T1/de not_active IP Right Cessation
  • 1998-06-02 EP EP98928737A patent/EP1017517B1/de not_active Expired - Lifetime
  • 1998-06-02 DK DK98928737T patent/DK1017517T3/da active
  • 1998-06-02 DE DE69811697T patent/DE69811697T2/de not_active Expired - Fee Related

Patent Citations (5)

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