Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F42—AMMUNITION; BLASTING
  • F42B—EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION
  • F42B5/00—Cartridge ammunition, e.g. separately-loaded propellant charges
  • F42B5/02—Cartridges, i.e. cases with charge and missile
  • F42B5/16—Cartridges, i.e. cases with charge and missile characterised by composition or physical dimensions or form of propellant charge, with or without projectile, or powder
• • C—CHEMISTRY; METALLURGY
  • C06—EXPLOSIVES; MATCHES
  • C06B—EXPLOSIVES OR THERMIC COMPOSITIONS; MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES
  • C06B45/00—Compositions or products which are defined by structure or arrangement of component of product
  • C06B45/02—Compositions or products which are defined by structure or arrangement of component of product comprising particles of diverse size or shape

Definitions

• the technical sector of the present invention is that of propellant charges of ammunition with metallic or non-metallic casings.
• compact propellant charges have been proposed, that is to say blocks of one or more powder mixtures produced in particular under hot pressure in the presence a thermosetting binder in proportions varying from 5 to 10%, most often.
• the manufacturing process for these blocks is relatively long and requires, in addition to cooking, the use of a mold resistant to pressures of the order of 10 8 Pa.
• the compact propellant charges thus obtained have insufficient dimensional stability when subjected to thermal cycles of accelerated aging.
• the compressed powder blocks expand and contract, which results in an evolution of the structure of the binder considerably disturbing the ballistic behavior.
• it is essential to subject the compacted loads to one or more thermal stabilization treatments.
• the compressed block frequently breaks. In these two cases, there is a significant adjustment during the firing which results in a significant increase in the pressures developed in the weapon.
• propellant units Another major drawback of the propellant units lies in the fact that they must have a diameter substantially equivalent, but not greater, than that of the opening of the sockets in which they are introduced; in many cases. these sockets have a significant constriction at their upper part where the projectile is fixed, which prevents their use with compacted loads.
• the invention aims to remedy the aforementioned drawbacks by providing a propellant charge comprising at least two powders whose filling coefficient is significantly greater than that of bulk loads and which does not require any compacting operation. It also aims to provide a propellant charge which can be applied to a socket of any kind with or without necking. It also aims to provide a load which can be introduced into a socket automatically or semi-automatically very quickly. It also has the aim of conferring on the fuel socket loads a suitable mechanical strength.
• the subject of the invention is therefore a propellant charge of ammunition for weapons of all calibers intended to increase the filling coefficient of a metallic or combustible case, characterized in that it is constituted by the association of a powder with perforations and a monotubular powder according to the respective percentages 60 to 85% and 15 to 40% and a coating material according to a small percentage.
• the propellant charge can be constituted by the association of a powder with perforations and a powder with spherical grains according to the respective percentages 65 to 80% and 20 to 35% and a coating material according to a small percentage.
• the propellant charge can be constituted by the association of a perforation powder, a monotubular powder and a powder with spherical grains according to the respective percentages by mass 60 to 85%, 15 to 40% and 0 to 20 % and a coating material in a small percentage.
• the percentage of coating material is between 0.5 and 3.5% relative to the total mass of powder.
• the coating material is an oily binder, for example dibutylphthalate or a polyisocyanate, in particular a diisocyanate.
• the coating material is a thermosetting prepolymer, for example a polyurethane.
• the mass of powder is greater than that used with the casings without constriction. It is therefore necessary to significantly increase the percentage of binder to intensify its role as superficial combustion moderator, so that the pressure generated in the weapon is compatible with it.
• the grain dimensions of the three powders must be adapted to the caliber of the ammunition and it is preferable that the thickness of each of the powders is substantially equivalent, the thickness of the monotubular powder generally being the smallest, which is advantageous from the point of view of dimensional association, a ballistic correction being brought about by a more advanced surface moderating treatment.
• a very first result obtained by the loading according to the invention is a very significant increase in the filling coefficient of the sleeve which reaches at least 1,200 g / dm 3 compared to the loading carried out automatically with bulk powder.
• the coating material plays the role of additional surface moderator of combustion.
• the constituents of the charge after filling the sleeve are transformed into a solid aggregate having a considerable mechanical resistance which is particularly suitable for the loading of combustible sleeves.
• a fuel assembly with good mechanical strength is thus obtained.
• Polyisocyanates, thanks to chemical reactions of connection with the nitrocellulose of the powders lead to fixed loads having mechanical properties comparable to those obtained from thermosetting binders.
• the frozen loading in situ therefore does not float as is the case for previously compacted loads and is very resistant to thermal aging cycles, for example a thermohygrometric cycle.
• an axial channel When carrying out large loads, for example for ammunition, of 120 mm, an axial channel must be made in a known manner in the load so as to facilitate ignition, to ensure operational safety and to obtain good regularity. shooting. On the other hand, it is sometimes necessary to provide an axial channel in the loadings for necked bushing, especially when this necked is very accentuated, which most often corresponds to high performance ammunition.
• the powders usually used in the manufacture of 20 to 30 mm caliber ammunition must undergo a very extensive moderating treatment; this treatment can be carried out in part or in whole by increasing the proportion of binder.
• the procedure is as follows or in an equivalent manner.
• the powders are mixed according to the percentages indicated in a few seconds in a mixer with a coating material suitably chosen in small proportion and then the non-solidified mass thus obtained is introduced into the socket.
• the positioning of the projectile makes it possible to perfect the packing of the load.
• the coating material is a thermosetting prepolymer
• the ammunition thus produced is then subjected to baking at a temperature below 100 ° C.
• the load solidifies in the socket and adheres to the wall thereof. It can therefore be seen that the loading according to the invention does not require the use of high pressure, for example of the order of 8.10 7 Pa, which requires the production of a compacted loading and can be implemented on sockets having or not a constriction.
• Examples 1 to 3 illustrate the embodiment according to which the coating material is an oily binder and Examples 4 to 8 the embodiment according to which the coating material is a thermosetting prepolymer.
• the speed of the projectile is conventionally measured at 25 meters; the pressure is conventionally measured using a piezoelectric device; the percentages indicated are percentages by mass.
• the percentage of binder is calculated relative to the total mass of powder.
• the powders used consist of nitrocellulose (simple base).
• the monotubular cylindrical grains have a thickness of between 0.3 and 0.4 mm; the cylindrical grains with 19 holes have a web of 0.36 mm; the spherical grains have a diameter of 0.35 to 0.47 mm.
• the loading density is: 1,200 g / dm 3 .
• the loading density is: 1,200 g / dm 3 .
• thermosetting prepolymer known under the name of "HSV •, marketed by the company” V os Schemie Soloplast •. This prepolymer is of the polyurethane type. After filling the cartridges, the ammunition is subjected to a baking at 90 ° C for approximately 2 hours.
• the loading density is: 1,200 g / dm 3 .
• Ammunition is produced under the same conditions as above with the same percentages of powder but with 1.5% of HSV.
• the loading density is: 1,200 g / dm 3 .
• the dispersion of the marksmanship results increases when the proportion of binder increases.
• Ammunition produced according to Example 5 is subjected to 10 aging cycles of 24 hours each (thermo-hygrometric cycle).
• Piezoelectric pressure P 4094.19 5 Pa.
• the loading density is 1,200 g / dm 3 .
• the loading density is: 1,200 g / dm 3 .
• the loading density is: 1,200 g / dm 3 .

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Crystallography & Structural Chemistry (AREA)
• Organic Chemistry (AREA)
• Paints Or Removers (AREA)
• Containers And Packaging Bodies Having A Special Means To Remove Contents (AREA)
• Agricultural Chemicals And Associated Chemicals (AREA)
• Polyurethanes Or Polyureas (AREA)
• Furnace Housings, Linings, Walls, And Ceilings (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Curing Cements, Concrete, And Artificial Stone (AREA)
• Operating, Guiding And Securing Of Roll- Type Closing Members (AREA)
• Manufacture Of Alloys Or Alloy Compounds (AREA)

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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• 1978
  • 1978-04-13 FR FR7810854A patent/FR2422925A1/fr active Granted
• 1979
  • 1979-04-06 AU AU45899/79A patent/AU534179B2/en not_active Expired
  • 1979-04-10 NO NO791216A patent/NO146516C/no unknown
  • 1979-04-11 EG EG219/79A patent/EG14237A/xx active
  • 1979-04-11 ES ES479526A patent/ES8200184A1/es not_active Expired
  • 1979-04-12 BE BE0/194568A patent/BE875534A/xx not_active IP Right Cessation
  • 1979-04-12 IT IT21822/79A patent/IT1115185B/it active
  • 1979-04-12 DE DE7979400244T patent/DE2961805D1/de not_active Expired
  • 1979-04-12 ZA ZA791753A patent/ZA791753B/xx unknown
  • 1979-04-12 EP EP79400244A patent/EP0005112B1/fr not_active Expired
  • 1979-04-20 IL IL57101A patent/IL57101A/xx unknown

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