RU2360213C2 - Igniter cap - Google Patents

Abstract

FIELD: weapons and ammunition.

SUBSTANCE: igniter cap comprises metal cup with shock-igniter composition arranged in the form of two layers and covered with protective layer on top. Layer of shock-igniter composition located at cup bottom is arranged from pressed explosive substance with combustion rate at 10 kgf/cm² higher than 13.0 cm/s. The second layer is arranged from tetrazene and inertial sensitiser.

EFFECT: increased reliability of igniter cap operation.

3 cl, 2 tbl

Description

The invention relates to the field of cartridge production and can be used in igniter capsules (KB) for small arms cartridges.

One of the main requirements for KB is to ensure the safety of their operation with wide ranges of striking energy in various systems of small arms. In this case, strict requirements are set for the safety of production of KB and their operation.

Currently, the developers of cartridges have become urgent tasks in developing reliable non-rusting, environmentally friendly and environmentally friendly HF.

This task is necessary to solve many problems: increase the resource of small arms trunks; increase the reliability of the shot; excluding heavy metals from entering the human body. The latter is especially important when shooting indoors.

In Russia, cartridges with KB containing explosive mercury are still being produced [1]. These KB in many ways do not meet modern requirements. They have a strong rusting effect, relatively low heat resistance, high cost and scarcity of raw materials (mercury, antimony sulfide, brass).

Mercury and its compounds are harmful substances with a low maximum permissible concentration, which also complicates the production of KB, and make firing with such cartridges dangerous to health. KB used in foreign and domestic ammunition with shock-ignition compounds (UVS) based on lead trinitroresorcinate (TNRS) [2], although they are non-rusting, their heat resistance and environmental cleanliness are not at all better than those of explosive explosive explosives.

In addition, the well-known airborne propulsion systems based on TNRS are not sufficiently stable in igniting propellant charges at negative temperatures. Therefore, the task of creating a new non-rusting KB from non-deficient components and inexpensive raw materials without heavy metals has become urgent. Known KB according to US patent [3] has a low heat resistance, the impossibility of its preparation by the traditional dry method and the possibility of delamination of the components due to a significant difference in their densities.

Known KB [4], selected as a prototype as the closest to the proposed.

This KB contains a metal cap with a hitch of a UVS, covered with a protective layer on top, while the UVS is made in the form of two layers: a shock composition layer located at the bottom of the cap, and a layer of igniter composition.

The weight ratio of the layers of the impact composition to the ignition composition is 0.04 ... 0.95. as a layer of the impact composition used:

- compositions based on lead trinitroresorcinate;

- explosive mercury or compositions based on it;

- a mixture of potassium salt of dinitrobenzofuraxan with a sensitizer;

- composition of diazodinitrophenol, potassium salt of azodinitrophenol and a sensitizer.

As a layer of igniter composition, quick-burning explosives with low sensitivity to impact were used, for example, monobasic potassium stifnate or a mixture of monosubstituted potassium stifnate or diazodinitrophenol with combustible binder components.

KB prototype showed good results on the ballistic characteristics of the cartridges, but at the same time had a number of disadvantages. These include:

1. When using lead or explosive mercury compositions as the impact composition of lead trinitroresorcinate, environmental indicators of the shot deteriorate, and in the presence of explosive mercury, the barrel is corroded after firing.

2. The prototype does not indicate the basic, specific physico-chemical characteristics of sensitizers. Therefore, the ratio of the sensitizer with the components indicated in the prototype may not be optimal, which will lead to a deterioration in the stability of the ballistic characteristics of the cartridges.

3. The metal caps for KB for small arms cartridges are mainly made of brass or other non-ferrous metals. Currently, the use of non-ferrous metals in small arms cartridges is becoming economically disadvantageous.

The task of the invention is to develop a safe, reliable, non-rusting, environmentally friendly, economically viable KB, ensuring the stability of the ballistic characteristics of the cartridges.

The problem is solved due to the fact that potassium styphnate or a high-energy component is pressed onto the bottom of the cap, the burning rate of which at 10 kgf / cm ^{2 is} higher than 13 cm / sec. On the fast-burning component is placed an impact composition of tetrazene and an inert sensitizer having the following physicochemical characteristics:

- density 2 ... 4.2 g / cm ³ ; - Mohs hardness 3 ... 7, or microhardness 350 ... 1000 kg / mm ² ; - specific heat 0.06 ... 0.25 Kcal / g - coefficient of thermal conductivity 0.0015 ... 0.0032 cal / (cm / s)

Some types of glasses, ceramics, silicon and its oxides have such physicochemical characteristics.

The metal cap is made of steel clad with non-ferrous metals, while the thickness of the cladding layers can be different for each side and vary from 4 to 10% of the thickness of the tape from which the cap is made. Currently, copper is used for plating steel, which has been carefully tested during the development of a new cost-effective HF. When the coating thickness is less than 4% of the tape thickness, the reliability and health of KB is not ensured. With a layer thickness of more than 10% of the thickness of the KB tape, they become economically disadvantageous and their operating time characteristics change. The metal cap can be made of steel protected by a chemical coating with a thickness of 3 to 9 microns. Checked KB, made of steel, protected by a varnish film. With a coating thickness of 3 to 9 μm, KB worked reliably and withstood accelerated aging tests with satisfactory results. When the coating thickness is less than 3 μm, the cap material is corroded. With a coating thickness of more than 9 μm, operational reliability is not ensured.

In existing KB, this set of essential features has not been identified, which allows us to consider this technical solution as meeting the criterion of "Novelty."

To obtain stable ballistic characteristics of the shot, it is necessary to ensure the reliability of the ignition of the propellant charge, the optimal combustion mode and the maximum completeness of its combustion. When KB is triggered, a force of flame arises, consisting of hot gaseous products of combustion of an air-blast furnace and heated sensitizer solid particles. The temperature and flow rate of gaseous products and airborne solid particles should be such that during the shot there is a rapid ignition of the propellant (powder) charge, its combustion and complete combustion when a bullet (projectile) reaches about 2/3 of the barrel length.

In addition, in order to improve the ballistic characteristics of weapons during firing, it is necessary to solve the problem of increasing the power of KB while maintaining the dimensions.

To substantiate the optimal characteristics of KB, experimental studies were presented, the results of which are shown in tables 1 and 2.

KB were manufactured using the following technology:

- from a specially selected steel clad with non-ferrous metals, a cap of the required size was made using standard technology;

- caps were placed in assemblies and a dose of monobasic potassium styphnate or other quick-burning explosive substance (BB) was filled in them, whose burning speed at 10 kgf / cm ^{2 was} higher than 13 cm / sec, and this dose of explosive was pressed at a specific pressure of 1000 ... 1500 kgf / cm ² ;

- a mixture of impact composition — tetrazene with an inert sensitizer, which had the above physicochemical characteristics — was placed on the explosives;

- a drop of varnish was dripped onto the impact composition, the assembly with caps was placed on the vibration stand and vibration was carried out for 3 ... 5 minutes;

- then drying was carried out at a temperature of 40 ... 60 ° C and ready-made KBs were equipped in a sleeve using conventional technology.

Also equipped with steel caps protected by a chemical coating.

It should be noted that in the tested KB the ratio of igniter and impact compositions was similar [4], the ratio of sensitizer to initiating explosive remained the same.

Tables 1 and 2 show the results of ballistic tests of cartridges with a new KB and KB prototype, the reliability of the KB, and the cleanliness of the combustibility of the powder charge. The tables show that the new KB is slightly superior to the KB prototype.

In the shock-ignition composition, a sensitizer (glass) was used with physicochemical characteristics within the above limits. Changing the sensitizer parameters beyond these limits leads to a deterioration in the safety or reliability of HF.

The metal cap was made of steel plated with a layer of copper 6% thick to the thickness of the bottom of the cap.

The version of the cap coated with a special varnish with a thickness of 8 μm was tested.

The results of the checks are satisfactory.

Thus, the proposed KB for small arms cartridges is justified and meets the requirements for HF.

Table 1 Name
KB Ballistic characteristics Delay
Ignited
ny, ms Weight
unburned
balances
shots, g Mark
gunpowder Weight
charge M _{25 Wed} ,
m / s ΔV ₂₅ ,
m / s P _{max avg}
kgf / cm ² ΔP _max
kgf / cm ² Prototype VT 3.10 815 21 2916 118 0.20 0.010 New VT 3.10 817 17 2822 93 0.16 0.005

table 2 Sensitivity characteristics Prototype New Security KB when exposed to a falling load weighing 307 g, height, cm, at 0% response 3 3 Reliability KB, cm, at 100% operation eleven 9 Reliability KB after exposure for 4 hours at a humidity of 100%, a temperature of 60 ° C and after the test shaking for 30 minutes (80 beats per minute with a height of 150 mm) fifteen 10

Information sources

1. P.P. Karpov “Means of initiation”, Oborongiz, 1999, p. 127.

2. Composition non-rusting shock K-2-1, Technical conditions TU-04-031-1-78.

3. US patent No. 4675059.

4. RF patent No. 2285229 C2.

Claims (3)

1. Capsule igniter containing a metal cap with a shock-ignition composition made in the form of two layers and covered with a protective layer on top, characterized in that the layer of the shock-ignition composition located at the bottom of the cap is made of 1000-1500 pressed at a specific pressure kgf / cm ² explosive with a burning rate at 10 kgf / cm ² above 13.0 cm / s, and the second layer is made of tetrazene and an inert sensitizer having:
density 2-4.2 g / cm ³ Mohs hardness 3-7 specific heat 0.06-0.25 kcal / (g coefficient of thermal conductivity 0.0015-0.0032 kcal / (cm / s) 2. The igniter capsule according to claim 1, characterized in that the metal cap is made of steel tape plated with copper with a thickness of the cladding layers from 4 to 10% of the thickness of the tape. 3. The igniter capsule according to claim 1, characterized in that the metal cap is made of steel protected by a varnish coating with a thickness of 3 to 9 microns.