JPS6251693B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a draw punch for cutting out a metal plate;
In particular, it relates to a draw punch for punching or cutting out enlarged holes in metal plates, etc. in places where it is difficult to reach, such as power distribution boxes and terminal boxes. A draw punch generally consists of a male punch member, ie, a cutter head, and a female die.The female die and the male punch member (cutter head) hold a workpiece metal plate with a small hole drilled in advance, and insert a bolt into the female die. Insert the cutter head through the hole in the die and the hole in the metal plate, screw it into the threaded hole in the cutter head and the nut, and rotate the nut to push the cutter head into the metal plate and cut the metal with the same size as the inner diameter of the recess in the female die. The mass is punched out, thereby forming an enlarged hole in the metal plate. Examples of such draw punches are e.g. US Pat. No. 2,237,069
It is stated in the number.

The present invention provides a draw punch that incorporates a cutter head with two opposing sloped surfaces that intersect each other at the centerline of the punch. The unique design of the cutter head in accordance with the present invention allows for easy removal of the stamped metal mass because it splits the metal mass into two pieces.

In the draw punch disclosed herein, the female die associated with the cutter head or male punch member is not new and consists of a cylindrical body closed at one end. The inner diameter of the recess, which extends over substantially the entire length of the cylinder, defines the diameter of the hole punched in the metal plate. At the closed end of the cylinder,
A hole is drilled that aligns with the threaded hole in the cutter head. The present invention relates to a cutter head or male punch member 10 having an axially threaded hole 15 therethrough. The outer diameter 20 of the cutter head 10 is adapted to fit within the inner diameter of a recess in a female die (not shown). The cutter head of the present invention has the second to fourth cutter heads.
As shown in the figures, the rib members 30, 30' have a plurality of surfaces 25, 25' that are inclined or spiral with respect to the top surfaces thereof. Inclined surfaces 25 and 2
5' each extend over a semi-circular portion of the cutter head 10 and are symmetrical when viewed from above as shown in FIG. In other words, one inclined surface 25 corresponds to 1/2 pitch of a helix, and the other inclined surface 25' also corresponds to 1/2 pitch of a helix. Rib members 30, 30' are formed at the top of the inclined surfaces 25, 25', respectively. The diametrical dimension of the rib members 30, 30' is
It has the same diameter as the cutter head 10 and is divided by the diameter of the hole 15. In other words,
The ribs 30, 30' extend diametrically from one cutting edge 45 of the cutter head 10 to the other cutting edge 45', excluding the hole 15. Each rib member 30, 30' has an upper side surface 3 on each side thereof.
5, 40', 35', 40, one side 35 of the rib member 30 connects to the uppermost end of the corresponding inclined surface 25 at an upper rounded joint 47;
The other side surface 40' connects to the lowermost end of the corresponding sloped surface 25' at a lower radiused articulation 47'. Similarly, one side 3 of the rib member 30'
5' connects to the uppermost end of the corresponding inclined surface 25' at an upper rounded joint 47, and the other side surface 40
is connected to the lowermost end of the corresponding inclined surface 25 at a lower rounded articulation 47'. In the illustrated embodiment, a pair of inclined surfaces 25, 25';
Rib members 30, 30' are shown connected at the ends of each inclined surface at articulations 47, 47'.

In operation, a male punch member or cutter head 10 and a female die (not shown) are positioned opposite each other with the metal sheet to be cut sandwiched between them. A bolt is inserted through the hole in the female die and the previously drilled hole in the metal plate, and the bolt is screwed into the threaded hole 15 in the cutter head 10.
Next, a nut is screwed onto this bolt to tighten the cutter head and female die. The cutter head is then progressively pushed into the metal plate, whereby the cutting edges 45 and 45' progressively cut into the metal plate at diametrically opposed points to cut out an enlarged hole, while simultaneously pushing the cutter head into the metal plate. diametrical rib 3
The metal block into which 0.30' is cut out is cut into two semicircular pieces. In this way, the metal block stamped from the sheet metal is formed by rounded articulations 47, 4 at the uppermost ends of each inclined or spiral surface 25, 25'.
The ribs 30, 30' located at 7' make it easy to remove the stamped metal mass. The diameter of the metal mass is defined by the edges or cutting edges 45, 45' of the inclined surface. Sloped surface 2 to increase the strength and rigidity of the punch
The connecting portions between 5 and 25' and the side surfaces 40 and 40' of the ribs are rounded connecting portions 47 and 47'.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the cutter head of the present invention, FIG. 2 is a side view of the cutter head, and FIG. 3 is a perspective view of the cutter head seen diagonally from above on the left side of FIG.
FIG. 4 is a side view of the cutter head seen from the right side of FIG. 10: Cutter head, female die, 15: Screw hole, 25, 25': Inclined surface, spiral surface, 3
0, 30': Rib, 45, 45': Cutting edge, edge, 4
7,47': Rounded joint.

Claims (1)

[Scope of Claims] 1. A male punch member adapted to be used in cooperation with a female member for punching a metal lump into two pieces from a workpiece, the male punch member comprising: The main body has an axial through hole 15 for receiving a pushing member for inserting and extracting the female member into and out of the female member. a pair of sloped surfaces 2 that slope upward in opposite directions;
5, 25' are formed, each sloping surface being provided with a cutting edge 45, 45' extending over the entire outer periphery of each sloping surface to constitute a cutter means; A rib member 30, 30' is formed at the uppermost end, extending across each of the inclined surfaces from the respective cutting edge to the through hole, and projecting upwardly from each of the inclined surfaces. The rib members together define transverse cutter means extending across the end face of the body except in the area of the through hole, whereby the male punch member engages the female member. When pushed into the female member with a workpiece held between them, the cutting edges 45, 45' on the outer periphery of each of the inclined surfaces punch out a metal lump from the workpiece, and the pair of rib members 30, 30 A male punch member characterized in that ' is configured to divide the metal lump into two parts. 2 The main body has a cylindrical shape, and the cutting blades 45, 4
The male punch member according to claim 1, wherein 5' is an arcuate shape. 3 The rib members 30, 30' are connected to the cutting edge 4.
5. A male punch member according to claim 1, wherein the leading edge is 5,45'. 4. The male punch member according to claim 1, wherein the through hole is a screw hole for removably fixing the pushing member.