JPH11322483A - Igniter for solid rocket motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the density and the calorific value per unit weight or gas amt. produced per unit time and to decrease the weight for required energy by constituting an igniter essentially comprising Ti and PTFE (polytetrafluoroethylene). SOLUTION: The igniter is produced by compounding about 40 to 80 pts.wt. Ti and about 20 to 60 pts.wt. PTFE as the main components and a binder, and forming into pellets. The binder is incorporated by about 1 to 20 pts.wt. The pellet is preferably formed into 0.1 to 20 mm size. The particle size of metal Ti used is preferably 20 to 80 μm. Or, a part of Ti may be substituted with Mg. The density of PTFE is preferably about 2.17 g/cm<3> . The PTFE is used in a molding powder or fine powder state, and preferably about 5 to 200 μm in size when used as the source material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid rocket motor using a solid fuel such as a composite propellant or a double base propellant as a propulsion source. It is about gunpowder.

[0002]

2. Description of the Related Art As a igniting charge for a solid rocket motor of this type, a black powder (a mixture of charcoal, sulfur, nitrite, etc.), for example, is known as a pressure ignition type. Examples of the method include boron / nitrite (B / KNO ₃ type: a mixture of metal boron powder and nitrite (potassium nitrate)), and other Al / NH ₄ C
Mixtures of 10 ₄ , Al / KClO ₄ , B / KClO ₄ and the like are known.

Further, as an energy ignition type, for example, a magnesium / Teflon type (Mg / PTF) is used.
E type: Metal magnesium powder, Teflon powder, and in some cases, a mixture of fluorine and the like, which is basically the same as the hot particle ignition type, or propellant type (composite type propellant, double base type propulsion) Drugs) are known.

As a solid rocket motor ignition device, for example, a pyrotechnic ignition device as shown in FIG. 1 is known.

In the pyrotechnic type ignition device 1 shown in FIG. 1, a pellet-shaped igniter 3 is placed in a case (or basket) 2 having a flame outlet 2a, and an ejection hole 4a is provided on the left side of the case 2 in the drawing. And an auxiliary charge 6 is inserted between the discharge plate 4 and the base block 5, and an electric detonator (squib, initiator) 7 and an electric lead wire 8 for igniting the auxiliary charge 6 are provided. It has a structure with

The ignition device 1 having such a structure is usually provided on the side opposite to the nozzle side of the motor case, and in the case of a spherical rocket, is incorporated in the motor case near the nozzle.

[0007] Then, the ignition charge of the electric detonator 7 is first ignited by the electric signal transmitted through the electric lead wire 8 to burn the auxiliary charge 6, and then the pellet ignition charge 3 is further ignited by the combustion. Is burned, and the flame and combustion products generated by the combustion of the igniting charge 3 reach the surface of the solid propellant in the motor case through the flame outlet 2a, and the solid propellant ignites and burns, thereby propelling the solid rocket. Will be done.

In addition, there is a pyrogen-type igniter suitable for a small rocket motor ("Rocket Engineering" published on January 27, 1993).

[0009]

The igniting charge for a solid rocket motor has a high flame temperature, a high burning speed, a large amount of heat per unit weight, and a large amount of heat per unit time. Large amount of gas generated
Characteristics such as good ignitability in a low-pressure atmosphere are required.Therefore, it is possible to increase the density and generate a large amount of gas per unit time or the same volume. The challenge was to make it lighter and also smaller and more compact.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is capable of increasing the density and generating a large amount of heat per unit weight or generated gas per unit time. It is an object to provide a solid rocket motor igniter which can be made lighter and also smaller and more compact with respect to the required energy.

[0011]

According to the first aspect of the present invention, there is provided an ignition charge for a solid rocket motor, which is mainly composed of Ti and PTFE.

In the embodiment of the igniter for a solid rocket motor according to the present invention, as described in claim 2, 40 to 80 parts by weight of Ti and PTFE: 20 parts by weight.
It can be mainly constituted by a ratio in the range of ６０60 parts by weight.

Similarly, in the embodiment of the solid rocket motor igniter according to the present invention, the solid rocket motor may have a pellet shape including a binder.

Similarly, in an embodiment of the solid rocket motor igniter according to the present invention, the solid rocket motor has a pellet shape containing 1 to 20 parts by weight of a binder as described in claim 4. Can be.

Similarly, in the embodiment of the solid rocket motor ignition charge according to the present invention, as described in claim 5, the size of the pellet can be 0.1 to 20 mm. .

Similarly, in the embodiment of the solid rocket motor ignition charge according to the present invention, the metal particle size of Ti may be 20 to 80 μm.

Similarly, in the embodiment of the igniter for a solid rocket motor according to the present invention, as described in claim 7, a part of Ti may be replaced by Mg.

[0018]

The igniting charge for a solid rocket motor according to the present invention is mainly composed of Ti and PTFE as described above, and PTFE (polytetrafluoroethylene) used here is, for example, , TFE (tetrafluoroethylene) by suspension polymerization represented by the following formula.

[0019]

Embedded image

The density of this PTFE (C ₂ F ₄ ) is about 2.
^{17g / cm 3 (2.14~2.20g / cm} 3 approximately)
And P which is a fluororesin having similar properties
FA (copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether: density: about 2.15 g / c
m ³ ) or FEP (copolymer of tetrafluoroethylene and hexafluoropropylene: the density is about 2.15 g /
cm ³ ), PCTFE (polychlorotrifluoroethylene: density is about 2.13 g / cm ³ ), etc., can be used by partially or completely substituting PTFE.

These PTFE and the like can be used as a molding powder, a fine powder, a dispersion, or a granulated type. It can be used as a raw material, and the particle size when used as a raw material is more preferably about 5 to 200 μm.

In this case, if the particle size is smaller than 5 μm, the production cost tends to increase, and if it is larger than 200 μm, the mixing amount of the metal tends to decrease.

The present invention is not limited to the powder type or the granulated type, but may be used in the form of a sheet containing Ti metal particles and adhered to the surface of a solid propellant grain (for example, a solid propellant grain burning on an end face). Is also possible.

The density of Mg in the conventional Mg / PTFE igniting charge is 1.74 g / cm ³ , whereas the density of Ti in the Ti / PTFE igniting charge according to the present invention is 4.50 g. / Cm ^3, it is a high density solid rocket motor ignition charge.

In addition, compared with the conventional Mg / PTFE-based igniting charge, the Ti / PTFE-based igniting charge according to the present invention has a large amount of generated gas per unit time and a high calorific value twice as high per unit weight. It will be something that can be done.

In the Ti / PTFE-based igniter according to the present invention, the main component Ti is 40-80.
It is more preferable that the mixing ratio of the PTFE and the PTFE be 20 to 60 parts by weight. If the amount of the Ti is less than 40 parts by weight and the amount of the PTFE is more than 60 parts by weight, the high density And the combustion rate decreases, the calorific value per unit weight or the amount of gas generated per unit time tends to decrease, and
The amount of Ti is more than 80 parts by weight and also PTF
If the blending amount of E is less than 20 parts by weight, the calorific value per unit weight or the amount of generated gas per unit time tends to decrease in this case as well.

When the Ti / PTFE-based igniter is used in the form of a pellet or a sheet, it is not easy to maintain the shape in the form of a pellet or a sheet with only Ti and PTFE. Preferably, the binder is used to maintain the shape of a pellet or a sheet.

In this case, the compounding amount of the binder is 1
If the amount of the binder is less than 1 part by weight, it tends not to be sufficient to hold the Ti / PTFE-based igniter in a pellet shape or a sheet shape. If the amount is large, the characteristics of the ignition charge tend to decrease.

When used in the form of pellets, the size is desirably 0.1 to 20 mm. If the size is smaller than 0.1 mm, the granulation cost tends to increase. If it is large, the calorific value per unit weight or the amount of gas generated per unit time tends to decrease.

Further, it is desirable that the metal particle size of Ti is 20 to 80 μm. If it is smaller than 20 μm, spontaneous ignition tends to occur and handling tends to be dangerous. The ignitability is poor and the combustion efficiency tends to decrease.

Furthermore, Ti / PTFE according to the present invention
In system-based igniters, it is possible to replace part of Ti with Mg, and it is possible to obtain the effect of improving the easiness of ignition possessed by Mg. However, if the replacement amount is increased, the density decreases. Therefore, it is difficult to obtain a sufficient heat generation amount or gas generation amount.
It is desirable to keep it within 0% by weight.

[0032]

According to the first aspect of the present invention, there is provided an ignition charge for a solid rocket motor according to the present invention.
Since it is a Ti / PTFE-based material mainly composed of E, it is possible to further increase the density as compared with the conventional Mg / PTFE-based material, and to generate heat per unit weight or per unit time. A greater advantage is that the amount of gas generated can be higher and the igniter or igniter can be made lighter and smaller and more compact for the required energy. .

And, as described in claim 2,
By being mainly constituted by the ratio of 40 to 80 parts by weight of Ti and 20 to 60 parts by weight of PTFE, the combustion speed is further improved, and the calorific value per unit weight or generated gas per unit time is obtained. This has the distinct advantage of being able to further increase the amount.

According to the third aspect of the present invention, it is possible to obtain a good combustion state of the Ti / PTFE-based igniting charge by forming a pellet containing a binder. Significant effects are achieved.

In addition, as described in the fourth aspect, by forming a pellet containing 1 to 20 parts by weight of a binder, Ti / PTFE can be obtained without impairing the characteristics of the ignition charge. A remarkably excellent effect is obtained that a good combustion state of the system ignition charge can be obtained.

Furthermore, by setting the size of the pellets to be 0.1 to 20 mm, the igniting charge for a solid rocket motor having a high flame temperature and a high burning speed is provided. A remarkably excellent effect is obtained.

Further, as set forth in claim 6, by setting the metal particle size of Ti to 20 to 80 μm, a solid rocket motor having a high combustion rate, a large amount of heat generation and a large amount of generated gas is provided. A remarkably excellent effect that the igniter can be used.

Further, as set forth in claim 7, by partially replacing Ti with Mg, a solid rocket utilizing the characteristic of improving the easiness of ignition possessed by Mg. A remarkably excellent effect of being able to be used as a motor ignition charge is provided.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the solid rocket motor ignition charge according to the present invention will be described below, but it goes without saying that the present invention is not limited to only such embodiments.

Ti metal particles having a particle size of 22 μm, PTFE having a particle size of 150 μm, and a liquid binder (trade name: Viton, manufactured by DuPont) were mixed at the compounding ratio shown in Table 1, and also shown in Table 1. It was formed into pellets of a size to obtain an ignition charge for a solid rocket motor.

Next, a dropping sensitivity test was performed on the ignition charge for a solid rocket motor using a dropping sensitivity tester shown in FIG. 2 to measure the dropping sensitivity.

The drop hammer sensitivity test was performed according to JIS K4810.
As shown in FIG. 2, the hammer sensitivity tester 11 is mounted on a gas vent cover 13 provided on a steel anvil 12 as shown in FIG. Two placed cylindrical rollers (12 x 12 mm) 14,1
4 between the sample 15 and the electromagnet 1
The hammer (with a weight of 5 kg) 17 held by 6 is dropped on the sample 15, and explosives (here, an ignition charge for a solid rocket motor) are determined from the relationship between the height read by the staff 18 and the occurrence of explosion. ) 15).

The hammer sensitivity is represented by the grades (grades 1 to 8) shown in Table 3 of the above JIS, and the results are also shown in Table 1.

Further, by performing a combustion test on each solid rocket motor ignition charge, the combustion speed (at a pressure of 20 atm) was examined.
The results are shown in FIG.

[0045]

[Table 1]

As shown in Table 1, as shown in FIG. The igniters of Nos. 2 to 4 were low in hammer sensitivity, high in safety, high in burning speed, and had good characteristics as igniters for solid rocket motors.

Then, N, which has a smaller amount of Ti,
o. No. 1 does not burn with the igniting charge, and No. 1 contains a small amount of PTFE. With the igniter of No. 5, the combustion speed exceeded 22 mm / s.

It should be noted that the igniter in which Ti was replaced with a small amount of Mg also showed good characteristics.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional explanatory view showing a structural example of an ignition device for a solid rocket motor.

Fig. 2 JIS used to evaluate the safety of explosives
It is an explanatory view (FIG. 2 (A)) showing an outline of a hammer testing machine established in K4810 and an explanatory view (FIG. 2 (B)) of an anvil portion for placing a sample.

Continued on the front page (72) Inventor Takuo Kuwahara 2 Nihonsan Motor Co., Ltd., 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa

Claims (7)

[Claims] 1. An ignition charge for a solid rocket motor, which is mainly composed of Ti and PTFE. 2. Ti: 40 to 80 parts by weight, PTFE: 2
The priming charge for a solid rocket motor according to claim 1, which is mainly constituted in a ratio of 0 to 60 parts by weight. 3. The igniting charge for a solid rocket motor according to claim 1, wherein the igniting charge includes a binder and has a pellet shape. 4. The solid rocket motor igniter according to claim 2, wherein the igniter comprises a pellet containing 1 to 20 parts by weight of a binder. 5. The solid rocket motor ignition charge according to claim 3, wherein the size of the pellet is 0.1 to 20 mm. 6. The solid rocket motor ignition charge according to claim 1, wherein the metal particle size of Ti is 20 to 80 μm. 7. The solid rocket motor ignition charge according to claim 1, wherein a part of Ti is substituted by Mg.