DE10047054C2 - Process for the production of fine perforations - Google Patents

Description

A fine perforation on an industrial scale and consistent quality in the past it has proven difficult and expensive. Drill - whether now with conventional means or by laser - quickly reaches its limits, if larger areas are to be perforated: Here processes are required where many holes / breakthroughs can be made at the same time. About these procedures counts the production of a negative tool with pins, cores, needles and. Like. As first step, followed by the actual perforation process by the negative work as a second step.

In the beginning it is known from US 52 47 151 A that by means of spark erosion from a Drop free-standing cores can be worked out. In this publication is about producing the tread pattern for the treads of (car) tires. Although the process described here, the profiling is very precise on the workpiece can transmit, there is no method apparent - and also not intended -, work the free-standing cores down to a minimum diameter. The suitable method of planetary eroding is described in DE 38 14 675 A1 described. The eroding electrode is made by cyclical lateral translations movements deflected relative to the die in such a way that dimensionally predeterminable there Bags can be worked out.

But there is also no teaching in this document for the production of fine Pins / cores.

The fineness of the perforation obtained depends directly on the diameter of the pins / cores / Remove the needles from the negative tool. So far there is a procedural one Limit that is about 0.5 mm. It is theoretically possible with the known Procedures also come under this measure; however, processing time and Reject rate exponentially.

The task and aim of the new method according to the invention is the economical, rational and safe production of the finest perforations down to 0.1 mm knife.

This goal is achieved by those stated in the main claim Features solved.

Possible embodiments of the invention are set out in the subclaims.

To the negative tool mentioned in the introduction with the finest pins / cores three process steps are necessary to produce. The first step is an eroding electrode, e.g. B. made of copper or graphite, with the smallest possible parallel Breakthroughs made. For example, the use of fine hundredweight is favorable drills with a chamfer at the edge of the opening.

Using this electrode, a z. B. made of steel existing die produced the negative tool. Due to spark erosion the material of the die was removed extensively, except where the through breaks are introduced into the electrode. The result will be freestanding on the die Cores worked out, which have approximately the same diameter as the breakthrough of the electrode, minus the double eroding gap.

In order to get the diameter of the cores even smaller, the third method is used connected step: The lowered electrode is deflected around the cores,  what during die sinking EDM via the planetary device or via another two CNC controlled axes is possible to a precisely predetermined extent. After at second step of the material removal in the vertical direction takes place this now in the horizontal direction so that the diameter of the cores is even reduced.

The deflection can be circular or linear; also the combination of these Movements are conceivable. As a result, z. B. round cores such with oval or lenticular cross-section - and the desired smaller diameter knives - to be made. With linear deflection only in a defined direction blade-like cores with a sharp edge are obtained.

The resulting negative tool with a very fine core stock now serves the Her position of the actual perforation. Basically here are all common perforations process conceivable and feasible, but some of which are high for the secondary tool Expect forces and thus accelerate wear and tear. Therefore in a preferred embodiment of the invention, the die with the fine cores as Part of a thermoplastic injection mold. In the enclosed Cavity of this injection mold protrude the cores in such a way that they with their When the tool is closed, point / cut the flat surface of the other Touch the tool surface. The plastic surrounds during the injection process Measure the cores, resulting in the finest perforations in the finished, molded part arise, the diameter of which is approximately the "lean" core diameter equivalent.

With the described method, especially if powerful CNC Controlled EDM machines are used, very fine and uniformly perforated Manufacture semi-finished products, e.g. caps or plaques, with diameters of up to 0.1 mm. at shorter pin shafts even smaller diameters are conceivable.

The method described enables rational production even over large areas Parts with both previously unattainable fine and even perforation. use areas are z. B. filtering purposes, liquid atomization or atomization of air in Water, for example in sewage treatment plants or for balneology.

Finally, an embodiment of the invention will be explained with reference to the drawing. The work steps are illustrated in Fig. 1-4.

Fig. 1 shows the starting position before the start of the eroding process. Above the still unprocessed die 2 , the electrode 1 is flanged to the receiving shaft 1 a and brought into position. In the electrode 1 1 breakthroughs have been introduced b c with Durchbruchsfase. 1

The vertical eroding process has already been completed in FIG. 2; The support plate / die base 2 a and the cores 2 b have remained from the die 2 , at the base of which, corresponding to the opening chamfer 1 c, a core chamfer 2 c has formed. The diameter D1 of the cores 2 b corresponds less the double eroding gap approximately to the inside diameter of the openings 1 b. With 3 a the lowering movement of this operation (Z axis) is designated.

Fig. 3 shows the electrode 1 in the working position with the die 2. Now the oscillatory or linear deflection phase begins - symbolized by the arrows 3 b with horizontal removal from the cores 2 b, the deflection radius being successively set to the desired residual diameter.

The final result can be seen in FIG. 4, the diameter D2 of the cores 2 b has been reduced by the preceding step at the predetermined amount.

drawing Legend

1

electrode

1

a receiving shaft

1

b breakthrough

1

c Breakthrough phase

2

die

2

a Support plate / die bottom

2

b core

2

c Core bevel

3

a Lowering movement during the eroding process

3

b Deflection during the eroding process

3

c Stroke in the starting position

Claims (10)

1. Process for the production of fine perforations, characterized in that
that the first method step is to produce an electrode ( 1 ) with the smallest possible parallel openings ( 1 b),
that in the second process step with this electrode ( 1 ) in the die-sinking EDM process, free-standing cores ( 2 b) are worked out from a die ( 2 ) which correspond to the arrangement of the openings ( 1 b) on the electrode ( 1 ),
that (2 b) (b 2) is reduced to around a predeterminable measure in a third process step the diameter of the cores by deflecting the electrode (1) in the erosion process by the cores, and
that in a fourth process step the fine perforation in the starting material is produced with the aid of the die ( 2 ) carrying the refined cores ( 2 b). 2. A process for the preparation of Feinstperforationen according to claim 1, characterized in that the fourth process step is an injection molding process, wherein the cores (2 b) carrying the die (2) forms one half of the injection molding tool, the cores (2 b) With the tool closed, just touch the opposite flat surface of the other half of the tool. 3. A method for producing fine perforations according to claim 1 and 2, characterized, that the end product of the processes described is an injection molded, finely perforated badge. 4. A method for producing fine perforations according to any one of claims 1-3, characterized in that the opening ( 1 b) and thus also the core ( 2 b) receive a chamfer / rounding at its base. 5. A method for producing fine perforations according to one of the claims 1-4 characterized, that is eroded with machines in which the deflection process on one exactly definable final diameter of the cores is controllable.   6. A method for producing fine perforations according to one of the claims 1-5 characterized, that is eroded with a CNC machine that oscillates on all sides movements as well as linear sideways movements of predeterminable directions, each perpendicular to the direction of the lower axis (Z axis). 7. The method for producing fine perforations according to any one of claims 1-6, characterized in that a circular deflection method is selected in which the openings ( 1 b) represent bores, with the result that the cores ( 2 b) predetermined as pins the apparent diameter. 8. The method for producing very fine perforations according to any one of claims 1-6, characterized in that the cores ( 2 b) are oval or lenticular in cross-section by different deflection amplitudes in the X or Y axis direction. 9. A method for producing fine perforations according to any one of claims 1-6, characterized in that the cores ( 2 b) are designed like a blade by deflection exclusively in a linear direction. 10. A method for producing fine perforations according to any one of claims 1-6, characterized in that cores ( 2 b) with a polygonally limited cross-section are formed by deflection exclusively in a plurality of linear directions.