RU2401412C1 - Electrical igniter with protection against static electricity discharges - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: electrical igniter (EI) with protection against static electricity discharges refers to electrical initiation facilities and can be used in pyrocartridge structure development intended for using for instance in opening, separation, disengagement, etc. systems. EI includes body where small socket with electric terminals and resistance bridge, header with igniting charge and main charge are installed. The igniting charge is made of compound based on organic high explosive agent and zirconium powder and is separated from main charge by metal cap. In this structure, relative density of igniting charge is less than 0.65 and the main charge is made of high explosive agent not sensitive to static electricity discharge.

EFFECT: simplification of device structure.

1 dwg

Description

The invention relates to the field of electrical means of initiation and can be applied in the development of designs of squibs intended for use, for example, in systems of opening, separation, disengagement, etc.

One of the urgent tasks in this field of technology is to ensure the safety of the design of the electric igniter associated with the exception of unauthorized operation from static electricity discharges (RSE).

Electro-ignition devices (EIs) are known, which include a housing in which a boot with two leads is installed, an incandescent bridge, an ignition hinge, separated from the igniter charge by a compensating washer and a sealing assembly consisting of a threaded sleeve, and a copper cone freely inserted into it. The igniter charge is made of a pyrotechnic composition, placed in a sealing cap and closed with a sealing bottom. To ensure protection of the structure from the RSE, insulating tubes are placed on the terminals, placed in the corresponding through holes of the bottom of the case, covered by a sealing plug (description of patent RU 2196954, published January 20, 2003). Thus, a limited gap is created between the outer surface of the terminals and the housing due to the thickness of the insulating tubes. The gap acts as an electric spark gap upon contact with the housing or terminals of the RSE.

The disadvantage of this solution is the presence of additional structural elements, leading to a complication of the design and the complexity of manufacturing.

Another EU is known (description of patent RU 2196292, published January 10, 2003), selected as a prototype and including a durable case, inside of which there is a plastic nozzle and a metal block with electrical leads and an incandescent bridge. A cavity is formed in the nozzle to accommodate the igniter charge and the sample, and in this case, the diameter of the cavity in the sample placement zone is smaller than in the charge placement zone. The nozzle is docked with a metal block with holes through which electrical leads are passed, separated from the block by glass insulators. In order to avoid unwanted tripping when exposed to RSE, a capacitor, coil and resistance are connected in parallel to the ignition circuit. For the strength of the connection between the shoe and the nozzle, a ring groove with slots is made in the shoe. The nozzle covers this section, thereby achieving their optimal connection, and in conjunction with the isolation of the terminals, unauthorized exit of gases from this end and protection against RSE are prevented. The disadvantage of this design is the need for the introduction of additional electronic elements, which complicates the design and its manufacture.

The technical result of the claimed invention is to simplify the design of the device.

The specified technical result when using the claimed invention is achieved due to the fact that in an electric igniter device with protection against static electricity discharges, which includes a housing in which a block with insulated electrical leads and an incandescent bridge is installed, a nozzle with an ignition hinge and a main charge that is not sensitive to RSE The igniter hinge is made of a composition based on an organic blasting explosive and zirconium powder and is separated from the main charge with a metal cap, while the relative density of the igniter is at least 0.65.

The separation of the ignition hinge from the main charge with a metal cap simplifies the process of pressing the ignition hinge into the device and eliminates the direct effect of an electric spark during RSE on the ignition hitch.

The choice of density and composition of the igniter hinge is associated with ensuring resistance to RSE without additional structural elements. Pressing the ignition hinge containing zirconium metal powder to a high relative density provides electrical conductivity along electric chains of metal particles and the spreading of electric current through the metal cap and the ignition hitch in the case of RSE without its ignition and then through the main charge to the body.

The drawing shows a General view of the inventive electric igniter device, where 1 is a housing, 2 is a shoe, 3 is a lead, 4 is a bridge, 5 is a nozzle, 6 is an igniter, 7 is a main charge, 8 is a cap, 9 is an adhesive fill.

An example of a specific implementation of the claimed device can serve as an electric igniter, including a case in the form of a glass of aluminum, inside of which a nozzle of press material is installed, forming cavities for the main charge and an ignition hinge, which contacts a nichrome wire glow bridge soldered to two terminals pressed into a block of press material. The igniter hinge is made of a compound protected by patent RU 2240994 (description published May 27, 2004) and is separated from the main charge by a nickel cap. The relative density of the igniter is ≈ 0.65. The main charge is made of a blasting explosive that is not sensitive to RSE. Electrical leads are made of enameled wire PEV-2-0.5 GOST 7262-78. The end face of the casing of the electric igniter device is rolled out from the side of the terminals, and the cavity between it and the block is filled with glue.

The claimed device operates as follows.

When applying electric current to the terminals 3 of the shoe 2, the glow bridge 4 is heated and the hitch 6 is ignited, the combustion products of which move the cap 8 and initiate the main charge 7, the gaseous combustion products of which lead to the destruction of the bottom of the housing 1, while the rolling of the housing from the terminals 3 1 and adhesive filling 9 exclude the possibility of gas breakthrough.

When static electricity is discharged between the casing and the terminals of the electric igniter, the electric current spreads over the entire volume of the ignition hinge 6 without igniting it.

Thus, using the inventive device, safety is achieved when exposed to a discharge of static electricity accumulated to the maximum by a person up to a voltage level of 25 kV with a capacitance of 200 pF without the use of additional protective structural elements.

Claims (1)

Electrostatic ignition device with protection against static electricity discharges, including a housing in which a block with insulated electrical leads and an incandescent bridge is installed, a nozzle with an ignition hinge and a main charge, characterized in that the ignition hitch is made of a composition containing an organic blasting explosive and zirconium powder , and is separated from the main charge by a metal cap, and the main charge is made of blasting explosive, insensitive static discharge, while the relative density of the igniter is at least 0.65.