Repeatable plasma generator and method for the same

Patent metadata

Field	Value
Publication number	US-9551547-B2
Application number	US-201214368925-A
Country	US
Kind code	B2
Filing date	Dec 17, 2012
Priority date	Dec 29, 2011
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

The invention relates to a method for the repeatable initiation of propellent charges in a weapon system, for example in the firing of projectiles from a barrel weapon, through electrical discharge between a rear electrode ( 22 ) and a front electrode ( 21 ) in a combustion chamber channel ( 3 ) filled with filler gas and comprising a combustion chamber combustion element ( 30 ), in which the filler gas in the combustion chamber channel ( 3 ) is ionized via a high-voltage potential from at least one ionizing electrode ( 100, 101, 102, 103 ), which ionization increases the electrical conductivity in the combustion chamber channel ( 3 ) so that an electrical flashover, through electrical discharge via a high-voltage generator ( 5 ) between the rear electrode ( 22 ) and the front electrode ( 21 ), is generated from the rear electrode ( 22 ) via at least one ionizing electrode ( 100, 101, 102, 103 ) onward to the front electrode ( 21 ), which results in hot ignition gas with plasma-like state being expelled from the combustion chamber channel ( 3 ). The invention also relates to a plasma generator for the said method, and to an ammunition unit comprising the said plasma generator.

First claim

The invention claimed is:

1. A plasma generator for the repeatable initiation of propellant charges in a weapon system through electrical discharge between a rear electrode and a front electrode in a combustion chamber channel, comprised in a combustion chamber combustion element and filled with filler gas, and disposed adjacent to a propellant charge, wherein the plasma generator comprises at least one ionizing electrode connected to an initiation circuit for ionizing the filler gas in the combustion chamber channel to raise the conductivity of the filler gas, as well as a second high-voltage generator arranged for electrical discharge into the filler gas of raised conductivity from the rear electrode via the at least one ionizing electrode onward to the front electrode, so that hot ignition gas is formed under high pressure.

2. The plasma generator according to claim 1 , wherein the initiation circuit comprises at least a first high-voltage generator and at least one circuit breaker connected to a first terminal of at least one capacitor, wherein the at least one ionizing electrode connected to the initiation circuit is connected to a second terminal of the said capacitor by at least one resistor comprised in an electrical circuit.

3. The plasma generator according to claim 2 , the initiation circuit, in addition to the resistor connected to the second terminal of the capacitor, comprises at least one inductor connected between the at least one ionizing electrode connected to the initiation circuit and the resistor.

4. The plasma generator according to claim 1 wherein the at least one ionizing electrode is fixed to the combustion chamber combustion element, wherein the at least one ionizing electrode is in open contact with the combustion chamber channel and is electrically connected to the initiation circuit.

5. The plasma generator according to claim 1 , wherein the at least one ionizing electrode is distributed with mutually equal spacing in the axial direction of the combustion chamber channel.

6. The plasma generator according to claim 1 , wherein the at least one ionizing electrode is distributed with equal spacing around the center axis of the combustion chamber channel.

7. The plasma generator according claim 1 , wherein the at least one ionizing electrode is four in number.

8. The plasma generator according to claim 1 , wherein the rear electrode is disposed on a rear end of the combustion chamber channel and is electrically connected to the second high-voltage generator, and the front electrode is disposed on a front end of the combustion chamber channel and is connected to earth, which rear and front electrodes are made of an electrically conducting material, and in the front electrode is disposed a gas outlet, which opens out towards the propellant charge.

9. The plasma generator according to claim 8 , wherein the gas outlet is a convergent nozzle.

10. The plasma generator according to claim 8 , wherein the gas outlet is a divergent nozzle.

11. The plasma generator according to claim 8 , wherein the gas outlet is a convergent-divergent nozzle.

12. The plasma generator according to claim 1 , wherein the combustion chamber combustion element is made of a material which is not consumed upon the initiation of the plasma generator.

13. An ammunition unit comprising a shell casing, a projectile, a propellant charge and a priming device, wherein the priming device is constituted by a plasma generator according to claim 1 .

Assignees

• Bae Systems Bofors Ab

Inventors

• Aberg Denny

Classifications

• H05H1/34

  Details, e.g. electrodes, nozzles · CPC title

• H05H1/52

  using exploding wires or spark gaps (H05H1/26 takes precedence) · CPC title

• F42C19/12

  electric · CPC title

• F42C19/0811

  characterised by the generation of a plasma for initiating the charge to be ignited · CPC title

• F42B5/08

  modified for electric ignition · CPC title