DD204877A1 - TOOL FOR PUNCHING IN ELASTIC MATERIALS, ESPECIALLY IN RUBBER - Google Patents

Abstract

The tools according to the invention are intended for punching in shape, in particular of elongated holes in elastic material of larger thicknesses. The invention aims to enable such breakthroughs by means of pre-drilled end or Fuehrungsbohrungen without distortion by machine. This is achieved by the punching tool Fuehrungsstifte 8, between which the punching blades 6, 7 are arranged, wherein between each two opposite punching knives 6, 7 is a vertical distance which is greater than the material thickness to be punched, and the corresponding die 2 a Edition 3 for the part to be punched out. A hold-down 5 and an ejection hole 11 are used for easy removal of the stamped part after the cut.

Description

Title of the invention

Tool sum Punching breakthroughs in elastic materials; especially in rubber 5

field of use

The invention relates to tools for punching breakthroughs, especially elongated holes in elasti -10 see materials of greater thickness, z. In rubber.

Characteristic of the known technical solutions

Punching tools for machining of rigid, non-elastic materials, such as metals and the like, are known in a variety of forms *

For punching relatively thin materials of any elasticity u.a. Punching blades of similar type known as for solid materials,

20So, ζ · Β. known from DE-EB 2848554, a punching knife for a geometrically arbitrary, auszustanzendes part of a plurality of cutting elements in a knife carrier, which also consists of releasably interconnected elements releasably to arrange, the cutting elements on.

Knife carrier height adjustable can be arranged «With this punching knife the goal is pursued to make the cutting easily nachschleifbar, in order to u» a. by means of the height adjustment to achieve a consistent punching accuracy and at the same time a longer service life, to ensure large numbers of stampings, especially in paper processing.

Furthermore, a punching knife, in particular for punching shoe soles, known from DE-EB 2740981, the cutting part is conventionally in one piece and by means of spot welding on the blade carrier

is solidified j- wherein the cutting part is made of a strip steel. This punching knife'is therefore also usable only for relatively thin materials, as well as all other known punching tools.

For elastic materials of greater thickness, z..B. a thickness which is greater than the smallest length dimension of the surface to be punched, punching tools of the type described above are not suitable because with the onset of knives due to the elasticity, the material is initially only compressed and simultaneously attracted towards the punch opening. The compressed material forms in the course of the cutting process between the cutting of the plug, which also elastically regresses after the cut and sets in the punch, whereby the intended form of breakthrough is not achieved because the all-spring-back material corresponding to the delay is not exactly the desired Line at the top, but was cut next to it, wherein approximately the desired cutting line is reached on the bottom depending on the nature of the support or the die, so that the breakthrough reaches an undesirable conical shape. To produce such breakthroughs in elastic material properly, is currently from o.g. Reasons to proceed as follows:

First, be at the ends or corners of the desired. Drill through holes with appropriately ground drills and then manually cut the cut edges with a knife. This is a very time-consuming and exhausting way of working, the qualitative result of which is heavily dependent on the skills of the human labor force.

Object of the invention

The invention aims to reduce the "amount of manual labor in producing apertures in elastic material of greater thickness and at the same time to increase the accuracy of the cut edges.

Explanation of the essence of the invention

The invention is therefore based on the object, the production of apertures in elastic material of greater thickness by means of a punching tool, which is designed so that the disadvantageous delay by the elastic laughter in three axes is largely compensated and a precise 'cut according to the intended contour possible is "

It has been found that due to the elasticity punching of the overall contour in a single cut without the disadvantageous delay in three axes is not possible. Accordingly, the punching tool is designed so that the transitions between each two cutting edges are prefabricated as a bore and the holes are used as a guide for the Sennit tool.

According to the invention, the object is achieved in that guide pins are arranged parallel to each other on a stamp plate according to the distance of the guide holes and at least two punching pins is attached to two guide pins, depending on the punching contour preferably between two opposing punching blades a vertical distance, the is preferably slightly larger than the material thickness to be punched, is provided and that the die with hold-down has a support which corresponds to the inner, horizontal surface between the guide pins and the punching blades.

In further training eats provided, the upper of two opposite punching knife? provided with an ejection hole

The cut with such a punch then proceeds as follows:

The pegs position the material by means of the pre-made tracking holes. "The lower punching knife ( _s) first press into the yielding material, pulling the material toward the inserting knife. Since the part to be punched out is supported by the support in the die, it can give way only to the knife in a limited amount and the cut takes place exactly at the intended contour line. Each severing by means of the or the lower knife springs the material to be punched out in the die Back opposite direction and is detected at the opposite section line of the upper knife or knives in the same way and severed.

When returning the stamp, the punched-out part is picked up because it clamps between the guide pins and the upper knife due to the high friction adhesion _? while the hold-down holds the workpiece as a whole. Upon reaching a position above the blank holder, the punched-out piece can be easily removed from the punching tool by a punch or plunger which is pushed through the ejection hole of the upper knife (s).

Ausführungsbeiipiel

The invention will be described below with reference to drawings on the example of e5.nes punching tool for slots,

In the accompanying drawings show:

Pig. 1 section through the tool transverse to the longitudinal axis Fig. 2. Cut parallel to the longitudinal axis

Pig. 3 horizontal section in Höhe.de3 upper knife

On a punch holder plate 9? which is attached to a head plate, Pührungsstifte 8 are attached _} whose center distance is equal to the distance between the axes of the final semicircles of the slot and whose diameter is slightly smaller than the diameter of these semicircles α.ls. Between the Pührungsstiften 8, the punching blades 6, 7 in a vertical distance from each other, which is slightly larger than the material thickness to be punched, arranged opposite, wherein the connection with the Pührungsstiften running approximately tangentially around the circumference is running The Pührstifte 8 extend over the cutting edge of the lower blade 6 and engage in corresponding holes of the die 2, which is mounted on a base plate 1. The die 2 has an inserted support 3, which is also connected to the base plate 1 and in its cross section of the inner surfaces between the Pührungsstiften 8 and the punching blades 6, 7 corresponds, so that the punching blades 6, 7 during the cut in the slots between the die body and support 3 can slide on the return stroke holds down the rubber plate, while the punched piece is taken with the punch up and in the upper position by means of a mandrel, which is passed through the discharge hole 11 of the knife 7 ejected can be.

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Claims (2)

** O * Erfindungsansprxich 1 · Tooling punching of perforations in elastic materials, especially in rubber, eg, of long  5 holes whose smallest length is smaller than the material thickness, using predrilled Mhrungsbohrungen at the ends of the respective cutting edges characterized in that on the punch plate (9) guide pins (8) corresponding to the distance of the guide holes are arranged parallel to each other and to two guide pins (8) at least one punching knife (6 and / or 7) is attached, wherein depending on the punching contour between two oppositely arranged punching blades (6; 7), a vertical distance, which is preferably slightly larger than the material thickness to be punched provided is. and in that the die (2) with hold-down (5) has a support (3) which corresponds to the inner horizontal surface between the guide pins (8) and the punching knives (6; 7), 2. Tool according to item 1, characterized in that in the or the upper punching blades (7) has an ejection hole (11) is provided. To do this, 1 soap drawings