US3643481A - Explosive-forming device - Google Patents

Explosive-forming device Download PDF

Info

Publication number
US3643481A
US3643481A US860703A US3643481DA US3643481A US 3643481 A US3643481 A US 3643481A US 860703 A US860703 A US 860703A US 3643481D A US3643481D A US 3643481DA US 3643481 A US3643481 A US 3643481A
Authority
US
United States
Prior art keywords
recess
pressure
chamber
charge
opening
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US860703A
Other languages
English (en)
Inventor
Heinrich Hertel
Dietrich Ruppin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3643481A publication Critical patent/US3643481A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
    • B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
    • B21D26/06—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure by shock waves
    • B21D26/08—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure by shock waves generated by explosives, e.g. chemical explosives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D26/00—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces
    • B21D26/02—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure
    • B21D26/06—Shaping without cutting otherwise than using rigid devices or tools or yieldable or resilient pads, i.e. applying fluid pressure or magnetic forces by applying fluid pressure by shock waves

Definitions

  • An explosive-forming device has walls surrounding a pressure chamber arranged to accommodate a workpiece and a die whose surface contour is to be imparted to the workpiece for shock-deformation of the latter into conformance with the surface contour.
  • a recess is provided in the wall means and has an opening communicating with the pressure chamber.
  • a gunpowder charge is accommodated in the recess and fills the same partly.
  • Damping means is arranged in the remainder of the recess intermediate the charge and the opening of the recess and fills at least a part of this remainder of the recess.
  • the present invention relates generally to devices for shock deformation of workpieces, and more particularly to such devices which have a self-venting pressure chamber, and still more particularly to such devices which use explosive charges for producing the shock pressure necessary to obtain the workpiece deformation.
  • 1,259,825 teaches an attempt to simplify such devices wherein the pressure chamber is bounded by stationary and movable walls, with the mass of the movable walls being so selected that the developing pressure in the interior of the pressure chamber is largely counteracteduntil it reaches the predetermined level at which venting is desiredby the inertia of the masses involved.
  • This is a significant improvement over the constructions known prior to this teaching because it makes possible the construction of devices of the type under discussion which are much simpler and therefore less expensive than heretofore possible, and which can be smaller and therefore more readily accommodated even where space is at a premium.
  • lf shock-pressure deformation devices utilize gunpowder to obtain the necessary pressure buildup, for instance in form of gunpowder cartridges, then the requirements made of the charge are considerably different from those which are for instance made of gunpowder used in ammunition for weapons.
  • This is especially important in devices of the type described in the aforementioned German Pat. No. 1,259,825 where it is essential for proper operation of the concept of maintaining the pressure chamber closed for the requisite deformation time by the inertia of the masses involved, that the pressure which develops upon combustion of the charge rise in as brief as possible a time to as high as possible a pressure peak.
  • Such pressure peaks are not desired in ammunition for weapons because of the high-and for weaponry purposes unnecessary-stresses which they impose upon the barrel of the weapon.
  • a further consideration in the type of device here specifically under discussion is the fact that the explosive charge is arranged adjacent the preferably liquid pressure-transmitting medium accommodated in the interior of the pressure chamber. This makes it difficult to obtain a complete combustion of the charge because under certain circumstances the pressure-transmitting liquid may prevent the combustion of a portion of the charge. This is another problem which is not encountered in ammunition for projectile weapons because in such applications the entire time period during which the projectile traverses the length of the weapons barrel is available for the combustion of the gunpowder charge.
  • an object of the present invention to provide an improved device for shock-deformation of workpieces.
  • a more specific object of the invention is to provide such a device which, when used with a gunpowder charge as the shock-pressure producing means is not possessed of the aforementioned disadvantages.
  • an explosive-forming device which, briefly stated, comprises wall means surrounding a pressure chamber arranged to accommodate a workpiece and a die having a surface contour which is to be imparted to said workpiece for shock-deformation of the latter into conformance with the surface contour.
  • the wall means includes at least two walls at least one of which is movable relative to the other between a chamber-closing chamber and a chamber-opening position and the wall means has an inertia so selected as to at least substantially equal the necessary shock-pressure for producing the predetermined energy level requisite to obtain the desired deformation of the workpiece so that upon exceeding of this shock pressure relative movement of the walls to chamberopening position results with concomitant venting of the chamber.
  • the shock-pressure producing means which is provided for producing a sudden increase in pressure in this chamber, includes a recess provided in the wall means and having an opening which communicates with the pressure chamber, and a gunpowder charge accommodated in this recess partly filling the same. Furthermore, the shock-pressure producing means includes damping means accommodated in the remainder of the recess intermediate the charge and the opening and filling at least a portion of this remainder.
  • the damping means is of course driven towards the opening of the recess so that intermediate the damping means and the combusting charged there develops the necessary space required for proper combustion. Because in accordance with the invention at least the portion of the recess which does not accommodate the charge is of substantially tubular configuration in its interior, the damping means is prevented from scattering under the stresses trans mitted to it by the igniting charge and thus serves to fulfill its separating function-separating the gunpowder charge from the pressure-transmitting liquid in the interior of the pressure chamber-for the period of time during which it moves to and out of the opening and into the pressure chamber. Of course, when it enters the pressure chamber it scatters but by this time the charge is already completely combusted. Furthermore, the presence of the damping means makes it possible to use coarser gunpowder and to thereby reduce the stresses on the wall means accommodating the charge.
  • the effectiveness of the device according to the present invention is largely independent of the type of material used for the damping means. It is therefore possible to use for this purpose materials which decompose into small particles upon entering into the pressure chamber, such as felt, paper board, nonvulcanized rubber and similar materials, and which therefore do not pose any threat of damage to the workpiece, the die or any other components contained in the pressure chamber, or to the walls of the pressure chamber.
  • FIG. 3 is a view similar to FlG. 2 but illustrating an additional embodiment of the invention
  • FIG. 4 is a view similar to H6. 2 but illustrating still a further embodiment of the invention.
  • FIG. 5 is also a view similar to FlG. 2 but illustrating yet another embodiment of the invention.
  • FIG. 1 is a somewhat diagrammatic cross section through an apparatus embodying the present invention. All such components which have not been considered necessary for an understanding of the present invention have been omitted to avoid confusion.
  • reference numeral 4 identifies an upper mass and reference numeral 5 a lower mass which are connected for movement relative to one another by the diagrammatically illustrated guide rods 7. Relative movement of the masses 4 and 5 thus occurs in direction axially of these guide rods 7.
  • the masses d and 5 constitute wall means and that their mass is so selected that when they are in the position illustrated in Fit]. 1 in which they define with one another an interior pressure chamber which is shown as being filled with a liquid pressure-transmitting medium 8, they will be capable of resisting the tendency of the internal pressure which develops and rises upon ignition of an explosive charge to move them apart, until such time as the pressure has reached the level necessary to deform the workpiece 110 which is shown as overlying a mold 9 accommodated in the interior of the pressure chamber and provided in this embodiment with a recessed surface contour into conformance with which the workpiece i0 is to be deformed.
  • the space 13 defined between the surface of the mold 9 and the underside of the workpiece it) may be evacuated by the evacuating conduit 12 which of course is connected to a suitable source of underpressure.
  • a recess is provided-in FIG. 1 in the mass 4-which accommodates an explosive gunpowder charge ll, for instance a cartridge of well known construction, an ignition device 6 for igniting the gunpowder charge and which may also be of any suitable construction and forms no part of the invention, and damping means 2.
  • the charge 1 fills a part of this recess
  • the damping means 2 fills a portion of the remainder of the recess.
  • An unfilled portion 3 of the recess constitutes an expansion space which is shown as having a cross-sectional area smaller than the smallest cross-sectional area of the part of the recess which accommodates the charge 1 and the damping means 2.
  • the shock pressure necessary to obtain the deformation of the workpiece it) rapidly develops in the pressure chamber and is contained therein against ventinguntil it reaches the aforementioned predetermined value at which it has performed at the desired deformation of the workpieceby the inertia of the masses 4 and 5.
  • the presence of the damping means in form of a solid plug prevents the ejection of as yet uncombusted grains of gunpowder into the pressure-transmitting liquid 8 and thus assures complete combustion of the charge ll.
  • the configuration of the recess may be different from that illustrated in FIG. i. in FIG. 2 the portion 3 corresponding to the portion 3 of FIG. 1 tapers conically towards the opening communicating with the interior of the pressure chamber and therefore with the pressure-transmitting liquid 8.
  • EEG. 3 A further embodiment for possible configuration of the recess is illustrated in EEG. 3. in this Figure the recess is of cylindrical configuration and of constant cross section throughout. its cross section corresponds to that of the explosive charge l, which in all of HUS. 2-5 is illustrated as accommodated in a cartridge.
  • the embodiment in FlG. 3 is simplest, because a cylindrical recess of constant cross section is easiest to produce. However, it does require that the material and geometry of the plug of damping material 2 be so selected that it will move through the portion 3 of the recess with the friction requisite for obtaining the desired results which have been outlined earlier.
  • the embodiment illustrated in HQ. t corresponds basically to that shown in FIG. ll, except that in hit ⁇ . at the plug of damping material 2' is not accommodated freely in the recess but instead in the interior of the cartridge 1', with reference numeral M identifying the actual gunpowder charge which is located upstream of the damping material 2, that is inwardly of the same. This facilitates readying of the device for use because the charge and the damping means can now be introduced into the recess as a unit.
  • HQ. 5 shows still another embodiment wherein the charge M- and wadding material-here identified with reference numeral 2.”--are accommodated not directly in the recess but instead in a cartridge casing l" which is configurated to conform precisely to the cross-sectional configuration of the recess.
  • the recess, and accordingly the cartridge casing l" will in FIG. 5 be seen to converge in cross section towards the outlet which communicates with the interior of the pressure chamber in which the pressure-transmitting liquid is accommodated.
  • the embodiment of H6. 5 is thus in effect a modification of FIG. 2 in so far as operation is concerned, and a modification of FllG. d in so far as the structure is concerned, namely the accommodation of the wedding material 2'.” in the cartridge casing.
  • the size of the space accommodating the wadding material-or left empty as in the case of the space of the portion in FlG. l-rnay be varied within a wide range, and similarly the volume of this space may be so varied. It has been found, however, that advantageous relationships will be obtained if the volume of the space accommodating the wadding material or, as in H6. i, being left free as identified with reference numeral 3, is approximately equal to that volume which is required for the charge. if the volume of the portion 3, which for the sake of simplicity is simply called the expansion chamber, is too large then the desired high working pressure can no longer be obtained. @n the other hand, if the volume is too small then the desired complete combustion of the guru powder charge is impossible to achieve.
  • the quantity of the charge, the configuration of the cartridge casing, the manner in which the charge is ignited, the type, geometry and size of the gunpowder grains as well as the size of the wadding material plug and the configuration of the expansion chamber are factors which contribute to defining the parameters both for the development of the working pressure and for the stresses which act upon the material sun rounding the recess when the charge is ignited.
  • it is a particular advantage of the invention that it permits the chargewhether or not provided with a cartridge casing-to be configurated in a variety of different ways. This makes it possible to select from a plurality of possibilities which all provide the same advantageous operation that one which is most suitable and most advantageous from a point of view of economy and ease of handling. This is of great importance because the charge is a significant factor in the operating cost of explosiveforming devices.
  • An eirplosive-forming device comprising wall means surrounding a pressure chamber arranged to accommodate a workpiece and a die having a surface contour which is to be imparted to said workpiece by shock deformation of the latter into conformance with said surface contour, said wall means including at least two wmls at least one of which is movable relative to the other between a chamber-closing position and a chamber-opening position, and said wall means having an inertia so selected as to at least substantially equal the necessary shock-pressure for producing the predetermined energy level requisite to obtain the desired deformation of said worlrpiece so that upon exceeding of said necessary shock-pressure relative movement of said walls to said chamber-opening position results with concomitant venting of said chamber; and shockpressure producing means for producing a sudden increase in pressure in said chamber, including a recess provided in said wall means and having an opening communicating with said pressure chamber, said recess including an inner portion of a smaller cross section and an outer expansion portion of a larger cross section intermediate and
  • a device as defined in claim l wherein said outer portion of said recess converges conically in direction towards said opening.
  • a device as defined in claim '7' wherein said recess diverges conically in direction inwardly of said opening, and wherein said casing conically tapers interiorly and eiiteriorly in direction towards said outlet, said wedding means completely filling that part of the interior of said casing which corresponds to said remainder of said recess.

Landscapes

  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Press Drives And Press Lines (AREA)
  • Shaping Metal By Deep-Drawing, Or The Like (AREA)
  • Portable Nailing Machines And Staplers (AREA)
  • Powder Metallurgy (AREA)
US860703A 1968-09-25 1969-09-24 Explosive-forming device Expired - Lifetime US3643481A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19681777207 DE1777207A1 (de) 1968-09-25 1968-09-25 Vorrichtung zur Hochleistungsumformung von Werkstuecken,insbesondere aus Blech,mit Hilfe von Schockwirkungsmitteln

Publications (1)

Publication Number Publication Date
US3643481A true US3643481A (en) 1972-02-22

Family

ID=5703089

Family Applications (1)

Application Number Title Priority Date Filing Date
US860703A Expired - Lifetime US3643481A (en) 1968-09-25 1969-09-24 Explosive-forming device

Country Status (5)

Country Link
US (1) US3643481A (enrdf_load_stackoverflow)
JP (1) JPS5111072B1 (enrdf_load_stackoverflow)
DE (1) DE1777207A1 (enrdf_load_stackoverflow)
GB (1) GB1247309A (enrdf_load_stackoverflow)
SE (1) SE364887B (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4910861A (enrdf_load_stackoverflow) * 1972-06-01 1974-01-30
JPS4910862A (enrdf_load_stackoverflow) * 1972-06-01 1974-01-30
US4599060A (en) * 1985-06-27 1986-07-08 The United States Of America As Represented By The United States Department Of Energy Die-target for dynamic powder consolidation

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3872523T2 (de) * 1987-04-15 1993-03-11 Res Foundation Inst Pty Ltd Formungsverfahren fuer metalle.
DE102005025660B4 (de) 2005-06-03 2015-10-15 Cosma Engineering Europe Ag Vorrichtung und Verfahren zum Explosionsumformen
DE102006037754B3 (de) 2006-08-11 2008-01-24 Cosma Engineering Europe Ag Verfahren und Vorrichtung zum Explosionsumformen
DE102006037742B4 (de) 2006-08-11 2010-12-09 Cosma Engineering Europe Ag Verfahren und Vorrichtung zum Explosionsumformen
DE102006056788B4 (de) 2006-12-01 2013-10-10 Cosma Engineering Europe Ag Verschlusseinrichtung für das Explosionsumformen
DE102006060372A1 (de) 2006-12-20 2008-06-26 Cosma Engineering Europe Ag Werkstück und Verfahren für das Explosionsumformen
DE102007007330A1 (de) 2007-02-14 2008-08-21 Cosma Engineering Europe Ag Verfahren und Werkzeuganordnung zum Explosionsumformen
DE102007023669B4 (de) 2007-05-22 2010-12-02 Cosma Engineering Europe Ag Zündeinrichtung für das Explosionsumformen
DE102007036196A1 (de) 2007-08-02 2009-02-05 Cosma Engineering Europe Ag Vorrichtung für die Zufuhr eines Fluids für Explosionsumformen
DE102008006979A1 (de) 2008-01-31 2009-08-06 Cosma Engineering Europe Ag Vorrichtung für das Explosionsumformen

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2935038A (en) * 1955-08-26 1960-05-03 Anheuser Busch Apparatus for metal forming using explosive pressures
US3036373A (en) * 1959-03-31 1962-05-29 Olin Mathieson Metal forming
US3045339A (en) * 1958-06-02 1962-07-24 Olin Mathieson Metal forming by explosive force through a solid gel
US3127923A (en) * 1961-02-17 1964-04-07 Rohr Corp High energy tube expander
US3195334A (en) * 1960-12-27 1965-07-20 William S Filler Explosive forming of metals employing a conical shock tube

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3217648A (en) * 1962-10-08 1965-11-16 Remington Arms Co Inc Combination wad column and shot liner

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2935038A (en) * 1955-08-26 1960-05-03 Anheuser Busch Apparatus for metal forming using explosive pressures
US3045339A (en) * 1958-06-02 1962-07-24 Olin Mathieson Metal forming by explosive force through a solid gel
US3036373A (en) * 1959-03-31 1962-05-29 Olin Mathieson Metal forming
US3195334A (en) * 1960-12-27 1965-07-20 William S Filler Explosive forming of metals employing a conical shock tube
US3127923A (en) * 1961-02-17 1964-04-07 Rohr Corp High energy tube expander

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Explosives From Space Age Shapes pp. 82 86, Aug. 25, 1958; Steel. *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4910861A (enrdf_load_stackoverflow) * 1972-06-01 1974-01-30
JPS4910862A (enrdf_load_stackoverflow) * 1972-06-01 1974-01-30
US4599060A (en) * 1985-06-27 1986-07-08 The United States Of America As Represented By The United States Department Of Energy Die-target for dynamic powder consolidation

Also Published As

Publication number Publication date
DE1777207C3 (enrdf_load_stackoverflow) 1974-06-06
GB1247309A (en) 1971-09-22
DE1777207A1 (de) 1971-04-01
DE1777207B2 (enrdf_load_stackoverflow) 1973-11-15
JPS5111072B1 (enrdf_load_stackoverflow) 1976-04-08
SE364887B (enrdf_load_stackoverflow) 1974-03-11

Similar Documents

Publication Publication Date Title
US3643481A (en) Explosive-forming device
US5289776A (en) Method and apparatus for producing large-caliber ammunition
US2072671A (en) Ammunition and propellant charge therefor
US2600678A (en) Rocket powder
US3648616A (en) Multistage power load
US3981244A (en) Pyramid projectile payload ejection device
US3575113A (en) Progressive burn shell
US2405507A (en) Charger for explosives
US3399622A (en) Reloadable shotgun shell device
US3828676A (en) Consumable explosive cartridges
US2877709A (en) Cartridge
JPS62502354A (ja) ショットガン用カ−トリッジ
GB2154717A (en) Charging cartridges
US4625648A (en) Projectile propelling charge and method of manufacture thereof
US4233902A (en) 76MM Rammable practice cartridge
US1812010A (en) Shell construction
US4759430A (en) Energy absorbing arrangements
US3179051A (en) Shot encapsulated gun shell assembly
US3730049A (en) Safety system for explosive powder storage bin
IL33100A (en) A caseless propellant cartridge with a charge of high compressiblity
EP0506150B1 (en) Launch unit for a mortar projectile
US3026801A (en) Shotgun shell
US3641796A (en) Apparatus for shock-forming of workpieces
US2541334A (en) Explosive assembly and method of making it
GB777840A (en) Improvements in or relating to signal rockets