DE1452798A1 - Process for the explosion deformation of workpieces and explosion deformation machine to carry out this process - Google Patents

Description

DIPL. ING, WT
B. WOODB 89 A UO SHURO » UMI »■ aiari

Augsburg, July 8, 1969

Official registration number: P 14 52 798.1

(N 25 766 Ib / 7c) App. Ref .: N. 59

National Research Development Corporation, 1, Tilney Street,

London W.l, England

Method for the explosion deformation of workpieces and explosion deformation machine for carrying out this

Procedure

The invention relates to a method for explosively deforming workpieces and in particular to such a method for Explosive deformation of sheet metal.

The development of explosion deformation technology, in which explosion shock waves generated by detonation of an explosive charge cause a workpiece to be deformed,

909849/0079

.. _ "..Ii uu j ^ e» - tm * - »'·'*" ■ ' * " ^J "

H52798

has taken fairly conventional approaches and the process of explosive deformation is now becoming very common for the Deformation of sheet metal or for the shaping or consolidation of materials, for example metal dust pressed pieces applied. The pressure surge resulting from the detonation is only of short duration and the peak pressure on the workpiece depends, apart from the size of the load, on the distance between the load and the workpiece. It has been shown that in general The more incompressible the pressure medium, the better the pressure is transmitted, so that the best results are obtained usually arise when the pressure medium is a liquid. Usually water is used as a pressure medium are used and such explosive deformation processes are carried out in open water containers.

A method for shaping workpieces by means of pulse-like pressure waves is known from US Pat. No. 3 090 II3, in which a liquid is also used as the transmission medium. The pressure waves generated by means of a projectile cause perforation and deformation at different points on a workpiece which is inserted into a suitable mold. In the known methods, the workpiece is fixed in the areas which delimit a point to be punched or deformed

- 2 -909849/0878

on the surrounding shape.

A deformation method is also known from British patent specification 392 635, in which a workpiece is pressed against a mold by means of high-pressure steam, whereby the workpiece is previously heated to a certain temperature will. Depending on the shape of the mold used, the compressive force of the high-tension steam results in the affected places a bulge of the workpiece. As a safety device, the device for exercising the the known method just mentioned has a sharp-edged opening which, if the operating pressure of the device is too high cuts open part of the workpiece, destroying it, so that the excess pressure can escape from the mold cavity can.

Finally, from US Patent 2 2H8 786 and from the French patent specification 921 098 still known method in which a workpiece with the aid of a Rubber cushion is pressed against a mold and thereby deformed and possibly also cut.

The known molding process has the disadvantage that in a certain workpiece area not both one Separation process as well as a deformation process under the

909849/0079

U52798

effect of a pulse-like pressure wave can. Such processing of a workpiece is possible using deformation processes in which a rubber cushion is used, but one then has to rely on the well-known advantages of pressure wave deformation waive.

The object of the invention is accordingly to be achieved in a method for shaping workpieces by means of pulse-like pressure waves in one and the same workpiece area to perform both a separation and a deformation can.

Based on a process for shaping workpieces, in which this caused by a pulse-like pressure wave against both a deformation and a perforation Form is driven, the invention achieves a solution to the specified object that on the workpiece by the Pressure wave-induced movement of the same against cutting edges arranged at a distance from the form first Separation process and then also with the help of the pressure wave a forward propulsion of the cut workpiece against the mold surface provided with protruding punches takes place.

-H-

909849/0079

By separating or cutting out the workpiece . Before it is pressed against the mold surface, the part of the workpiece that is to be deformed is removed from it Clamping is released and thereby a different material distribution under the pressure of the cut out Part of the workpiece by means of the pulse-like pressure wave to the mold surface results.

The above-mentioned, protruding from the mold surface * Hole punches can either be designed in such a way that they look at certain positions and positions when the workpiece is formed formally determined places a reduction in the strength of the material in the sense of a notch, Vorstansuhg or the like. So that after removal of the Workpiece from the explosion deformation machine, the cut-out area «can be easily broken out or since the complete discharge already takes place during the machining process under the effect of the blast wave.

In one embodiment of the explosion deformation machine according to the invention, a die is suitably shaped Projections bsw. back-worked areas are provided and the machine is arranged so that the on the workpiece acting 3to £ wave forces first the separation of a

909849/0079

Effect plate from the workpiece and then press this plate in and / or against the die with its projections or underworked areas and that this is a formed Product with pre-punched or pre-notched hole areas or with the desired »holes that have already been cut out arises.

An embodiment of the invention is shown below for example and with reference to the accompanying drawings. Put in the drawings dar:

Fig. 1 shows a vertical center length

section through part of an explosive deformation machine according to the invention,

Fig. 2 is a plan view of a, with the in

Fig. 1 shown explosion deformation machine producible Product, and

Fig. 3 shows a cross section through the in

2 of the drawings.

909849/0079

H52798 ■ }

As shown in Fig. 1 of the drawings, a metal sheet 2 is clamped by a clamping ring 3 on a tensioning or pulling table ¹ J. The clamping or pulling table ¹ J is formed by a plan of a Pormkammer 11 in which a die 5 is arranged. The cutting edges of a cutting tool 8 arranged on the die 5 are designed so that a blank is cut off from the workpiece 2 as soon as this workpiece moves towards the cutting tool. A pressure wave is generated in a pressure wave shaper I ¹ I by triggering a firing mechanism 13. Tie rods hold the pressure wave former 14 against the clamping ring 3 and nuts of these tie rods are on the flange-shaped Spannbzw. Pull table 4 on the one hand and on a cover plate 16 on the other hand, so that these two parts are firmly braced against each other.

As soon as the workpiece 2 is clamped, the pressure wave shaper 14 placed on the Pormkammer 11 and with the help of a sealing ring 17 with a circular cross-section sealed against the clamping ring 3. This means that the device is clear to ignite the charge. Under the impact of pressure waves the explosion, the board is first separated from the workpiece and then this board against the Die 5 pressed. The blank is given a final shape at the die; however, it protrudes from the surface of the

- 7 909849/0079

H52798 β

Die a plurality of projections 6 and 7 out, the edges of which are shaped so that at certain points the material the board breaks out. The projections 6 and 7 can represent parts of inserts which are inserted into the die; but they can also be plugged or simply placed on the surface of the die. In the latter case, however, is make sure that the projections are not displaced by the pressure wave or the pressure waves. Parts of the board butt against these projections 6 and 7 during the forming process, so that holes are broken out of the board and the board is properly applied to the surface of the die 5. The projections 6 are used, for example, to generate Through holes for screws or similar machine elements and the hole produced by the projection 7 can be arbitrary for various purposes, for example as shown in Figure 2 of the drawings. channels or columns'9 and a connecting line 10 are used for evacuation the molding chamber 11, as far as this is necessary. However, the surface of the die can also have further projections and / or have elevations that are used to produce stiffening ribs, decorative patterns, trademarks or others Patterns or facilities are used.

With a suitable position and selection according to shape and shape

909849/007 9

H52798 3

expansion of the projections or back-worked areas, it is possible to use the board to form a finished product • To form devices that previously had to be generated by one or more additional process steps in the known processes. The fact that such additional process steps are carried out after the usual shaping on the already shaped material had to, has made itself particularly unfavorable in the known processes.

Of course, the shape of the blank or the blank does not necessarily have to be symmetrical.

It should also be noted that the function of the method according to the invention on the workpiece or the board inherent inertia that takes effect when a shock wave occurs.

909849/0079

Claims (8)

H52798 ΛΟ Augsburg, July 8, 1969 Official reference: P IH 52 798.1 (N 25 766 Ib / 7c) Applicant: National Research Dev.Corp. Appl. Ref .: N. 59 patent claims 1. A method for forming workpieces, in which this by a pulse-like pressure wave against both a deformation as well as a perforation is driven shape, characterized in that on the workpiece caused by the pressure wave moving against cutting edges spaced from the mold first a separating process and then, likewise with the help of the pressure wave, a propulsion of the cut workpiece takes place against the mold surface provided with protruding punches. 2. The method according to claim 1, characterized in that the perforation by means of the punch provided on the punch, takes place in the cross section of rectangular cutting edges. 3. The method according to claim 1 or 2, characterized in that first the strength of at least one - 10 909849/0079 H52798 Area of the workpiece takes place in the sense of a pre-punching strongly reducing pressure wave effect and then through a subsequent process step a breakthrough or breakthroughs in the area or in the areas of reduced Strength are formed. 4. The method according to claim 3> characterized in that the pressure wave effect, which reduces the strength of the workpiece in the sense of a pre-punching, has already occurred the process step of the actual deformation of the workpiece is at least begun. 5. explosion deformation machine for performing the method according to any one of claims 1 to ¹ J, in which the workpiece is exposed to the action of a pulse-like explosion pressure wave and thereby a part of the workpiece is pressed into a die, characterized in that the die (5) has at least one projection (6, 7), I which during the shaping of the workpiece (2) rests on the part of the workpiece to be deformed and reduces the strength of the workpiece material at points of the workpiece determined in terms of position and shape in the sense of a punching or pre-punching so that there the holes to be produced can easily be broken out. - 11 - 909849/0079 6. Explosion deformation machine according to claim 5, characterized in that said die projection (6, 7) is shaped and arranged to accommodate the workpiece material breaks out during the formation of the workpiece part (2) to be deformed in the sense of a perforation of the workpiece. 7. explosion deformation machine according to claim 5, characterized by a device (8) for separating the workpiece part (2) to be punched during its formation Impact of pressure waves. 8. Explosion deformation machine according to one of claims 5 to 7 »characterized by tendons (3» * 0 for clamping the workpiece (2) in a certain position With respect to the die (5), furthermore by means of an explosion shock wave generator (12, 13, 14) and by such an arrangement of the separation tool (8) that this is during the molding of the workpiece under the action of the explosion shock wave applies to this and separates a plate (2) from it, which in turn, is pressed against the mold surface of the die and its projection (6, 7) in such a way that a molded Product with at least one hole is created. - 12 - 909849/0079 '/ 15- Blank page