DE2503263A1 - DEVICE FOR GAS EXPLOSION FORMING - Google Patents

Description

Dipl.-Ing. Dr. jot. ^ ^ * £ - '

Frank Arnold Nix - /

Patents T.vvk

6 Frankfurt a · ,; Main 70 <» _Βη » »·«

GartenstraL'e 123 {.OK) O ΔΌ 4

DIRECTION TO GAS EXPLOSION SUMiORMS

The present invention relates to non-cutting metal deformation, in particular devices for gas explosion forming.

This invention can be most advantageous in manufacture Intricately designed parts made of stamped sheet metal are used in aircraft industry, shipbuilding.

It is also possible to use the device for gas explosion forming in accordance with the present invention To be used in chemical and petroleum engineering as well as in boiler construction.

Devices for gas explosion forming are known, the one die, which is arranged on a plate, and an explosion chamber with a detonation tube abutting it, which are arranged on another plate that is rigidly connected to the first plate. Located in the detonation tube a gas mixture igniter. The die, the explosion chamber and the detonation tube are coaxial, in rows one above the other arranged. The inner surface of the explosion chamber has the shape of a truncated cone, the larger base of which is the Die and the smaller one facing the detonation tube.

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The explosion chamber is connected to a gas mixture source Connection, and in it are means for the exit of the combustion products of the gas mixture (see e.g. copyright certificate no.14870, issued in the USSE).

For stable propagation of the explosion wave in the gas mixture As is well known, the explosion chamber must have a specific composition have a certain taper angle · This angle should be greater than a certain critical angle the explosion wave in this chamber is destroyed. For the stoehiometric methane-oxygen mixture is E.g. the critical angle 25 °. In the non-cutting molding of parts with large dimensions, a conical explosion chamber of relatively great length is therefore required, which in turn causes an increased gas mixture consumption during the operation of the device.

Furthermore, such devices have a high metal requirement and are therefore expensive to manufacture.

It is the purpose of the present invention to eliminate the disadvantages mentioned.

The invention is based on the object of creating such a device for gas explosion forming in which the explosion chamber has such a constructive solution that makes it possible, while maintaining the in comparison to the known device identical main characteristics of the Forming process to reduce the external dimensions of the chamber

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and thus reduce the metal consumption for their production and to reduce the gas mixture throughput during operation of the device.

This object is achieved in that, in the device for gas explosion forming, in which the die for receiving the semi-finished product on one side and the explosion chamber adjoining the die on one side and connected to the gas mixture source with the detonation tube connected from the other, opposite side, which carries the gas mixture igniter, is arranged on the second parallel plate connected to the first plate, according to the invention in the Explosion chamber is a component in the form of a body of revolution, the outer surface of which with the inner surface of the Explosion chamber forms a gap filled with the gas mixture, the size of which is in the cross section of the explosion chamber changes in the direction of propagation of the explosion wave in such a way that

Detonation character

that the u of the gas mixture combustion in the explosion chamber is maintained.

It is useful for the component to be axially adjustable in the Arrange explosion chamber.

This offers the possibility of increasing the size of the gap between the end face of the component and the inner end face of the chamber change, in turn, maintaining optimal conditions

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of the detonation combustion sequence while working with various Gas mixture types guaranteed.

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It is no less useful if the component is a conical body, the base of which corresponds to the The front end of the detonation tube faces, and the inner side surface of the explosion chamber has the shape of a truncated cone whose larger base faces the die

Such shapes and the mutual arrangement of component and chamber result in the minimum external dimensions the device guaranteed.

It is useful if the component has a cavity which is adapted to the partial filling with liquid, as a result of which this component is cooled down during forming.

The hollow design of the component reduces its metal requirement and further increases the operational stability and performance of the device by forced cooling of the component.

It is also useful if the component is in a hollow, convex shape with the side wall made of an expandable material executed and the filling with liquid is adapted under a pressure, the size of which depends on the composition and the initial pressure of the gas mixture is selected.

This design of the component offers the possibility of changing its shape and dimensions with fluctuations in composition and concentration of the gas mixture supplied to the explosion chamber and thus the setpoint size of the deformation force of the To keep semi-finished products.

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It is also possible for the component to have the side surface which is equidistant from the inner surface of the explosion chamber and which is continuous Has channels that are formed in the body of the component in the direction of propagation of the explosion wave front and can be selectively covered to achieve a local deformation of the semi-finished product.

A valuable result can also be achieved, though the component has a teardrop shape and with the inner side surface the explosion chamber forms a gap in the form of a convergent-divergent nozzle.

In this gap, the passage of the combustion products is _t of the gas mixture of an increase in their speed in the divergent nozzle portion, and accordingly accompanied by an increase in the forces acting to be shaped semi-finished pressure.

In comparison to the known devices, the device designed according to the present invention requires for Gas explosion forming significantly lower investment costs for their production.

While maintaining the identical main characteristics of the Forming process (size and type of pressure distribution on the surface of the semi-finished product) also increases the gas mixture throughput during the operation of the device in comparison to the known devices 1.5 to 4 times and more.

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The present invention is explained below using a specific exemplary embodiment with reference to the associated Drawings explained in more detail; show it

Fig. 1, the inventive apparatus for Gasexplosionsumf ormen _t in overall view with a partial cutout,

2 shows the basic control scheme of the device for gas explosion forming,

3 shows a longitudinal section through the explosion chamber according to the invention; the first option - conical Component,

Fig. 4 ditto, the second embodiment - conical Component with a liquid-filled cavity,

Fig. 5 ditto, the third embodiment - ball-shaped component,

Fig. 6 ditto, the fourth embodiment - component with axial channels,

Fig. 7 ditto, the fifth embodiment - teardrop-shaped component.

The device for gas explosion forming includes a Base plate 1 (Fig. 1), which is attached to a concrete bedding 3 "by means of screw bolts 2.

one

On the base plate 1. "lower plate 4 is arranged, the

one
with top plate 5 by means of pillars 6 and nuts 7 in

rigid connection.

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Between the lower plate 4 and the upper plate 5 is an intermediate plate 8 is arranged on the columns 6 so as to be vertically displaceable.

The height adjustment of the plate 8 takes place via a wedge gear, that of a wedge 9 fastened to the plate 8 on its lower side and a wedge 9 which is arranged displaceably on the plate 4 movable wedge 10 consists. The wedge 10 stands with the rod of a compressed air cylinder set up on the base plate 1 11 in connection.

In the upwardly protruding section 12 of the base plate 1 and on the intermediate plate 8 there are rails 13 and 14, respectively attached, on which a cart 15 with the arranged on it Die 16 moves. The die 16 is on the cart 15 with snap pins 17 attached. A console 18 is attached to the cart 15, which is connected to the compressed air cylinder 20 via a link 19 stands that the movement of the cart 15 on the rails and 14 causes.

The explosion chamber 21 is attached to the upper plate 5, one of its sides extending over a rubber membrane 22 and a hold-down device 23 placed on the die 16 Semi-finished product "a" connects. -

On the opposite side joins the Explosion chamber 21, the detonation tube 24 with the gas mixture igniter 25 as which a spark plug can be used. The inner diameter of the detonation tube 24 is smaller than the minimum diameter of the explosion chamber 21.

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The explosion chamber is located above a gas supply system 26 (FIG. 2) 21 with sources 27 and 28 of gas components, methane and oxygen, respectively.

In the explosion chamber 21 is the component 29 (Fig. 3) arranged in the form of a body of revolution, the outer surface of which with the inside surface of the explosion chamber a gas mixture-filled Annular gap forms. The size of this gap in cross section the chamber 21 changes in the direction of propagation

that of the explosion wave front in such a way that the detonation character ^v gas mixture combustion in the explosion chamber 21 is maintained.

The component 29 represents a conical body which with its base facing the end of the detonation tube 24 (Fig. 1), and the inside surface of the explosion chamber 21 has the shape of a truncated cone, the larger base area of which faces the die 16. Through such mutual Arrangement of the component 29 and the chamber 21 ensures the minimal external dimensions of the device.

Detonation character
In order to maintain the _v of combustion, must

the explosion chamber can be designed with a specific angle for each gas mixture of a specific composition. Should this angle exceed a certain critical value ⁿ ci _fe ", the explosion wave released from the detonation tube with a small cross section into the explosion chamber is destroyed.

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The arrangement of the component 29 in the explosion chamber 21, which has an angle exceeding σ £, offers the Possibility of obtaining an angle ό £ »between the outer surface of the component 29 and the inner surface of the explosion chamber 21.

the ζ / / J

th, the smaller than the critical angle, is ie ⁰ ^ iv * This in turn allows the length of the explosion chamber 21 to be shortened and thus to reduce its metal requirement and the gas mixture throughput during operation of the device.

The component 29 is attached to the chamber 21 with studs 30 attached. On each stud bolt are between the inner face the chamber 21 and the component 29 adjusting disks 31 are arranged, with the aid of which the axial adjustment movement of the component 29 with respect to the chamber 21 is carried out in order to avoid a composition fluctuation to change the size of the gap between them in the gas mixture.

In order to reduce the metal requirement, the component 32 is (FIG. 4) designed to be hollow and closed with a cover 33, which opens an opening that can be covered with a blind flange 34 Has filling with liquid.

The presence of liquid in the cavity of the component 32 and its evaporation in the course of the detonation offer the possibility of the heating of the component 32 and thus that of the chamber 21 to reduce, which the working stability and performance of the device due to the constant weight of the ' Chamber 21 supplied gas mixture, increased.

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-. In the next variant, the component 35 (FIG. 5) is hollow and made ball-shaped from a stretchable material, as' which rubber is used.

The component 35i is wider for filling with liquid Called the shell, from above and below by means of bracket 36 Flanges 37 or 38 attached · The flange 38 is compact and welded in its middle part to a tube 39, via which the cavity of the shell 35 in the direction of arrow A Liquid is supplied under pressure. The flange 37 is welded to an outer tube 40, within which the tube 39 runs coaxially. The pipe 40 serves to drain the liquid from the cavity of the shell 35 ', as arrows B show.

The use of an elastic shell provides the possibility of changing the shape of the component 35 in the event of a composition or concentration fluctuation of the gas mixture constituents change, whereby the most favorable deformation conditions for the semi-finished product "a" (Fig. 1) are retained.

In order to reduce the gas mixture throughput even more and to ensure the possibility of local deformation of the semifinished product "a" according to the predetermined outline, the component 41 (FIG. 6) has a side surface which is equidistant from the inside surface of the explosion chamber 42, which is in the described example is conical and designed with the base surface facing the semi-finished product "A" to be deformed. The component 41 is fastened in the chamber 42 by means of ribs 43. In the body of the

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Components 41 are in the direction of propagation of the explosion wave front Channels 44 formed, which correspond to the outline of the to generating component (not shown) can be selectively covered with blind flanges.

To increase the on the Holbzeug "a" (Pig. 7) during the specific pressure acting upon its deformation, the component 46 in the example described has a teardrop shape and forms one with the inside surface of the explosion chamber 47 Annular gap in the form of a convergent-divergent nozzle 48.

The component 46 is secured with ribs 43a opposite the chamber walls 47.

The outflow of the products of combustion through the nozzle 48 is accompanied by an increase in velocity in its expanding part of the gas flow * and, accordingly, of an increase in the pressure acting on the semi-finished product "a" accompanied.

The device for gas explosion forming works like follows ·. ■ ·

The intermediate plate 8 is in the starting position

in the lower end position, the rails 13 and 14 are

which push, and the movable wedge 10 is extended inv (according to the drawing) left end position. The cart 15 with the die 16 stands on the rails 14, which are located in the section 12 of the base plate 1. The operator places the semi-finished product ¹¹ a "in the die 16. Then, the air cylinder

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turned on, the cart 15 on the backdrop 19 on the Rails 14 and 13 moved under the explosion chamber 21.

With the aid of the compressed air cylinder 11, the movable wedge 10 is in the right end position (according to the drawing) under the wedge 9 postponed. In the process, the intermediate plate 8 is lifted and the die 16 with the semi-finished product "a" placed on it touches without play the explosion chamber 21 is pressed.

In order to keep the composition of the gas mixture supplied to the explosion chamber constant, then this is evacuated by holding it over lock 491 manometer 50 and tap 51 connects to a vacuum pump 52.

After the cavity of the chamber 21 has been evacuated, the vacuum pump 52 is switched off and the gas supply system 26 is switched on. For this purpose, oxygen is supplied from an oxygen source A gas mixer 56 is fed via a manometer 53, an electrically controlled tap 54 and a return valve 55, which also contains methane from a methane source 27 via manometer 57, tap 58 and return valve 59 is fed.

The homogeneous gas mixture produced in the gas mixer 56 reaches the via tap 60, return valve 61 and lock 62 Detonation tube 24 and the explosion chamber 21. Simultaneously with the filling of the explosion chamber 21 with the gas mixture Switched on via lock 63 and taps 64 and 65 manometers 66 and 67, which register the pressure increase in the chamber.

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After reaching the required pressure, the gas supply system 26 (which includes gas mixer 56, tap 60, return valve 61 and lock 62) and the pressure gauges 66 and 67 switched off, and the device is ready for reshaping the semi-finished product "a".

The operator turns on the igniter 25, the the detonation tube 24 and the explosion chamber 21 filling gas mixture ignites. In the process, a forms in the detonation tube 24 Flame front wandering along this.

The plamefront propagates with increasing speed in the pipe 24, whereby an explosion wave arises therein, which in the explosion chamber 21 with the inside arranged component 29 is omitted. The component 29 is profiled in such a way that it enables a reduction in the volume of gas to be admitted into the chamber 21. In the annular gap that its outer surface forms with the inner walls of the chamber 21, the explosion wave propagates in a stable, non-destructive manner. When the explosion wave acts on the semi-finished product "a" The semi-finished product "a" is deformed via the rubber membrane 22, above which a thin layer of water lies, whereby it has the shape of the Die 16 assumes.

For removing the detonation products after forming

dpr is the. Chamber 21 connected via the lock 68 with atmosphere.

For complete cleaning of the chamber 21 and its partial cooling, the chamber 21 is traversed by a compressed air source 69

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blown via a tap 70, a return valve 71 »a T-piece 72, the return valve 61 and the lock 62 to the chamber 21 is connected.

After cleaning the chamber 21 from the detonation products, the compressed air supply is interrupted and then, after a pressure drop in the chamber 21 up to atmospheric pressure, the lock 68 over-

the covers that connects the explosion chamber 21 with "atmosphere.

Furthermore, the wedge 10 is cylinder with the aid of the compressed air 11 moved to the left end position, the intermediate plate 8 is lowered, and then the cart 15 with the die 16 with the aid of the compressed air cylinder 12 in the starting position rolled away. The punched part is lifted out, a new semi-finished product is placed and the forming cycle is repeated.

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Claims (5)

PATENT CLAIMS (Λ ·) Device for gas explosion forming _t in which the ^ y plate. Die for Ha Ib tool recording on a ^ and the one with your one side adjacent to the die and connected to the gas mixture source with that of the other, opposite side connected detonation tube, the one carries the gas mixture igniter, is arranged on ν ■ - second, parallel and connected plate, characterized in that in the explosion chamber (21) there is a component (29) in the form of a body of revolution, the outer surface of which corresponds to the inner surface of the explosion chamber (21 ) forms an annular gap filled with a gas mixture, the size of which changes in the cross section of the explosion chamber (21) in the direction of propagation of the explosion wave front in such a way that Detonation character that the ν of the gas mixture combustion in the explosion chamber (21) is maintained. 2. Device for gas explosion forming according to claim 1, characterized in that the component (29) with the possibility of an axial adjustment movement in the Explosion chamber is arranged. 3. Device for gas explosion forming according to claim 1, characterized in that the component (29) represents a conical body, the base area of which facing the front end of the detonation tube (24), 5 0 9843/0248 while the inner side surface of the explosion chamber (21) has the shape of a truncated cone, the larger base of which Die (16) is facing. 4. Device for gas explosion forming according to claim 3> characterized in that the component (32) is adapted to the partial filling with liquid Has cavity, whereby this component is cooled during forming. 5 device for gas explosion forming according to claim 1, characterized in that the component (35) made of a hollow, convex foam made of an expandable material and the filling with liquid is adapted under a pressure, the size of which is selected depending on the composition and initial pressure of the gas mixture. 6. Device according to claim 1, characterized that the component (41) has the side surface which is equidistant with the inner side surface of the explosion chamber (42) and has continuous channels (44) which are formed in the body of the component (41) in the direction of propagation of the explosion wave front and can be selectively covered to achieve a local deformation of the semi-finished product, 7 » Device for gas explosion reshaping according to claim 1, characterized in that the component (46) has a teardrop shape and forms an annular gap in the form of a convergent-divergent nozzle with the inside surface of the explosion chamber (47). 509843/0248 Blank page