Assembly including aft end igniter for rocket motor

Abstract

The present invention relates to an igniter assembly, including a blast tube provided with a supporting part formed in a cylindrical shape, and an aft-closure part having front and rear sides through which igniter combustion gas is emitted, an igniter disposed adjacent to the rear side of the aft-closure part and storing ignition pellet therein, and a blast tube stopper formed in a shape surrounding the supporting part, accommodating the igniter, and coupled to the rear side of the aft-closure part, wherein the aft-closure part includes a plurality of holes through which igniter combustion gas is emitted.

Claims

1. An igniter assembly, comprising: a supporting part formed in a cylindrical shape and having a supporting part hole penetrating in an axial direction of the supporting part; an aft-closure part with a first end provided at one end of the supporting part and formed to increase in diameter in a direction away from the supporting part; an igniter disposed adjacent to the aft-closure part and storing an ignition pellet therein; and a blast tube stopper formed in a shape surrounding the supporting part, and accommodating the igniter, the blast tube stopper being coupled to the aft-closure part, wherein the aft-closure part comprises: an inner circumferential surface facing a rocket motor propellant; an outer circumferential surface disposed to face the igniter; and a plurality of outflow tubes which are inserted into the aft-closure part to pass through the outer circumferential surface and the inner circumferential surface to discharge igniter combustion gas of the ignition pellet toward the rocket motor propellant, wherein the aft-closure part is formed to be on a shared center axis with the supporting part hole, and wherein the first end of the aft-closure part is of the same size and shape as the one end of the supporting part, so that gas produced by combustion of the rocket motor propellant by the igniter combustion gas is injected in a direction toward another end of the supporting part through the supporting part hole, and wherein each of the plurality of outflow tubes is formed in a T shape so as to cover at least a portion of the outer circumferential surface.

2. The assembly of claim 1, wherein the plurality of outflow tubes are arranged in a radial form.

3. The assembly of claim 1, wherein the igniter comprises an igniter case provided with case partitions defining a plurality of storage spaces for storing the ignition pellet therein.

4. The assembly of claim 3, further comprising an auxiliary ignition agent stored in one of the plurality of storage spaces to prevent an ignition delay.

5. The assembly of claim 3, wherein the igniter further comprises a case cover covering the igniter case.

6. The assembly of claim 5, wherein the case cover is made of urethane foam.

7. The assembly of claim 1, wherein the blast tube stopper further comprises a mounting portion for accommodating the igniter therein, and wherein the blast tube stopper comprises a heat-resistant material formed to surround the mounting portion.

8. The assembly of claim 7, wherein the blast tube stopper further comprises a coupling member disposed on the mounting portion such that an initiator or an ignition safety device is installed.

9. The assembly of claim 7, wherein the blast tube stopper further comprises a installing hole formed on the mounting portion such that a pressure sensor for detecting combustion pressure is installed.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments and together with the description serve to explain the principles of the invention.

(2) In the drawings:

(3) FIG. 1 is a view illustrating an igniter assembly with a disassembled aft-end igniter for a rocket motor, viewed from one direction;

(4) FIG. 2 is a sectional view of the igniter assembly with the aft end igniter mounted therein; and

(5) FIG. 3 is a disassembled sectional view of each component of a blast tube, a blast tube stopper and the igniter.

DETAILED DESCRIPTION OF THE INVENTION

(6) Hereinafter, an igniter assembly according to the present invention will be described in detail with reference to the drawings. In this specification, the same/like reference numerals are given to the same/like reference numerals in different embodiments, and redundant description will be omitted. A singular representation disclosed herein may include a plural representation unless it represents a definitely different meaning from the context.

(7) In general, a suffix such as module and unit may be used to refer to elements or components. Use of such a suffix herein is merely intended to facilitate description of the specification, and the suffix itself is not intended to give any special meaning or function. In the present disclosure, that which is well-known to one of ordinary skill in the relevant art has generally been omitted for the sake of brevity. The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings.

(8) It will be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.

(9) FIG. 1 is a view illustrating an igniter assembly with a disassembled aft-end igniter for a rocket motor, viewed from one direction.

(10) Referring to FIG. 1, the igniter assembly 1000 includes a blast tube 100, an igniter 200, and a blast tube stopper 300. The igniter 200 is mounted on one area of the blast tube 100 by the blast tube stopper 300.

(11) The blast tube 100 includes a supporting part 110 and a aft-closure part 120. The igniter 200 is installed in inside of the space formed by a toroidal shape aft-closure part 120. The aft-closure part 120 is formed to be gradually narrowed toward the blast tube 100. An inner space of the blast tube 100 is widened to be spaced apart from the aft-closure part 120.

(12) The igniter 200 stores ignition pellet therein.

(13) The aft-closure part 120 may have a circular outer circumference, and may have an oblique surface converging toward a center. However, a front surface of the aft-closure part 120 along which gas is emitted may be a curved surface. The front surface of the aft-closure part 120 is defined as a surface along which igniter gas is emitted, and a rear surface thereof is defined as a surface opposite to the front surface.

(14) FIG. 2 is a sectional view of the igniter assembly with the aft-end igniter mounted therein, and FIG. 3 is a disassembled sectional view illustrating each component of the blast tube, the blast tube stopper and the igniter.

(15) As illustrated in FIGS. 2 and 3, the aft-closure part 120 includes a plurality of outlet holes. The plurality of outlet holes are arranged at specific intervals to surround a central region of the aft-closure part 120. The aft-closure part 120 further includes outflow tubes 121 inserted into the plurality of outlet holes, respectively. Each of the plurality of outflow tubes 121 includes a hole through which the igniter gas flows in a direction that the outlet hole is formed. The plurality of outflow tubes 121 may be arranged in a radial form so that combustion gas of the igniter can be efficiently transferred to a rocket motor propellant.

(16) Each of the outflow tubes 121 is preferably made of an insulating material such as rubber. The outflow tubes 121 has a T-like shape and the hole formed through the outflow tubes 121 has a specific diameter. The specific diameter is set in a manner that the ignition pellet is discharged through the outflow tubes 121 without being completely burnt.

(17) A heat-resistant cap or the like may be provided in the hole, and in this case, deterioration in performance caused when the igniter is exposed to an extreme temperature environment can be prevented.

(18) The igniter 200 is disposed on one surface of the aft-closure part 120 into which the outflow tubes 121 are inserted. The igniter 200 includes an igniter case 210 and a case cover 220. The igniter case 210 may be made of urethane foam or the like, so as to have improved air-tightness and insulation property.

(19) The igniter case 210 has a toroidal shape surrounding the supporting part 110. The igniter case 210 includes case partitions 211 defining a plurality of storage spaces for storing ignition pellet therein. For example, ignition pellet 211a stored in the igniter case 210 may correspond to a pill type BKNO.sub.3. In this case, a burning time of an ignition agent may be maintained for a predetermined time.

(20) Meanwhile, at least one storage space of the plurality of storage spaces may be filled with an auxiliary ignition agent 211b which is in a form of powder or granule. Therefore, it may be possible to prevent an ignition delay from occurring when the ignition agent is ignited using energy supplied by an initiator or the like.

(21) The ignition powder is stored in each of the plurality of spaces defined by the case partitions 211. Accordingly, the ignition powder or the auxiliary ignition agent can be prevented from leaning to one side during transportation.

(22) The igniter case 210 in which the ignition powder 211a and the auxiliary ignition agent 211b are stored is bonded to the case cover 220 to form the integral igniter 200. The integral igniter 200 is then mounted on the blast tube stopper 300.

(23) The blast tube stopper 300 has a toroidal shape surrounding the supporting part 110. The blast tube stopper 300 is provided with a mounting portion 301 formed in a manner of recessing one surface thereof. The igniter case 210 is inserted into the mounting portion 301.

(24) Referring to FIG. 2, a height of the igniter case 210 and a thickness of the blast tube stopper 300 are not constant. For example, one area of the igniter case 210, in which the auxiliary ignition agent 211b is stored, has a relatively thin (short) height. Also, the mounting portion 301 of the blast tube stopper 300, in which the one area of the igniter case 210 is accommodated, is made thin and the blast tube stopper 300 itself is made thick. A coupling structure or a sensor unit may be provided at the blast tube stopper 300 in which the one area of the igniter case 210 is accommodated.

(25) In comparison, another area of the igniter case 210 in which the ignition pellet 211a is stored is formed relatively high (thick). The mounting portion 301 of the blast tube stopper 300, in which the another area of the igniter case 210 is accommodated, is made deep and the blast tube stopper 300 itself is made thin.

(26) The blast tube stopper 300 further includes a heat resistant material coated on one surface thereof which forms the mounting portion 301. Even though the blast tube stopper 300 is exposed due to combustion gas of the propulsion engine after the combustion of the igniter, the heat resistant material can minimize a problem that a temperature of the blast tube stopper 300 increases or the blast tube stopper 300 bursts.

(27) An initiator installing portion 302 is formed on the one area of the mounting portion 301 of the blast tube stopper 300. The installing portion 302 is preferably provided on the area where the auxiliary ignition agent 211b is disposed and the mounting portion 301 of the blast tube stopper 300 is made thin.

(28) An initiator or an ignition safety device may be coupled to the installing portion 302. Since the coupling portion 302 is screwed and has an O-ring mounting surface, the initiator or the ignition safety device can be separated or installed as needed. The installing portion 302 may be formed to face one storage space in which the auxiliary ignition powder bag is stored when the igniter case 210 is mounted on the blast tube stopper 300.

(29) Here, the initiator and the ignition safety device supply the energy for igniting the ignition powder and pellet. Accordingly, the initiator or the ignition safety device can be disposed adjacent to the auxiliary ignition powder, which may result in preventing an unnecessary ignition delay.

(30) A pressure sensor coupling hole 303 is formed on one area of the mounting portion 301 of the blast tube stopper 300. A pressure sensor for measuring combustion pressure of the igniter and the propulsion engine is mounted to the pressure sensor installing hole 303. However, when the combustion pressure measurement is not required, the pressure sensor installing hole 303 may be provided with an NPT screw structure such that a cap or the like can be inserted into the pressure sensor installing hole 303. Accordingly, when the pressure sensor is not disposed, air-tightness can be maintained.

(31) The blast tube stopper 300 on which the igniter 200 is disposed is closely adhered on one surface of the aft-closure part 120 and fixed to the blast tube 100 by an additional coupling device.

(32) A coupling member 310 may be mounted to the rear of the blast tube stopper 300 and connected to an additional structure. The coupling member 310 overlaps one area of an outer circumference of the blast tube stopper 300, and is formed in a circular toroidal shape to support the rear of the blast tube stopper 300.

(33) The configuration and method described in the foregoing embodiments may not be limitedly applied to the aft-end igniter described above, but all or some of the embodiments may be selectively combined so that various modifications can be made.