JPH08303998A - Consolidated propellant and manufacture thereof - Google Patents

Abstract

PURPOSE: To provide a consolidated propellant which has a high virtual specific gravity and retains its ability to burn before being consolidated. CONSTITUTION: A grain-shaped propellant consists of a mixture of two kinds of grains, one kind being larger grains and the other kind being smaller grains. The smaller grains have a major axis and a minor axis in ratios of 1.0-2.0. The minor axis of the larger grains is larger than that of the smaller grains by six times or more. As a result, a consolidated propellant obtainable has a high virtual specific gravity and is almost equal in gas-generating velocity to a like product before being consolidated. The consolidation also enables preventing instability of the combustion which may arise in a mixed grain system due to separation between the larger grains and smaller grains in a cartridge case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid propellant formed by solidifying a granular propellant with a solvent or an adhesive.

[0002]

2. Description of the Related Art In order to extend the initial velocity and range of a bullet for a gun, it can be achieved by elongating the barrel or increasing the maximum allowable pressure. However, there is a limit to the method because of the limitation of the weight and size of the entire system.
Therefore, attempts have been made to increase the energy of the propellant for firing bullets.

In order to increase the energy of the propellant, the energy of the propellant component is increased, the combustion pattern is changed so that the energy of the propellant is effectively converted into the kinetic energy of the bullet, or the propellant is changed. A method of increasing the amount of has been considered. With respect to attempts to increase the energy of propellant components, new energetic materials have been considered, but most of them have not yet been put to practical use. Also,
Attempts to alter the combustion pattern of propellant charge are found, for example, in US Pat. No. 4581998.
A device in which the combustion pattern changes rapidly during combustion has been devised.

Attempts to increase the amount of propellant are simply limited by the limited volume of the chamber. Therefore, by consolidating a gray propellant, such as a consolidate propellant, into a molded body with a certain shape, the maximum amount of the limited volume in the cartridge case is used, and as much propellant as possible is loaded. A method was devised. Regarding the consolidate propellant, for example, AD-A201
106, AD-A101163, AD-A084680
, One type of granular propellant was swelled with solvent, removed and transferred to a molding machine and squeezed,
By molding or coating a mixture of nitrocellulose, a plasticizer and a solvent on the outer surface of the propellant, transferring it to a molding machine and pressing and molding it. A temporary specific gravity of 3 times is achieved. In addition,
Here, the temporary specific gravity indicates the weight of explosive chargeable per unit volume. The use of these consolidate propellants makes it possible to load more propellants into a constant volume chamber than before.

[0005]

However, since this molding method increases the specific gravity by squeezing, the performance of the initial granular propellant is impaired, the initial velocity of the bullet is lowered, and the combustion performance of the original is lowered. When trying to approach the performance of granular propellant, the specific gravity decreases and the target performance cannot be achieved.

Further, in the case where the granular propellant has a shape in which a hole penetrates, there is a problem that the hole is crushed by squeezing and the performance of the propellant is impaired. An object of the present invention is to provide a consolidated propellant which has a higher temporary specific gravity than conventional propellants and which retains the combustion performance before consolidation.

[0007]

In order to solve the above-mentioned problems, the solid propellant of the present invention is a solid propellant using a granular propellant. It is composed of two kinds of mixed particles with particles, the ratio of the long axis to the short axis of the small particles is 1.0 to 2.0, and the ratio of the short axis of the large particles to the small particles is 6.0 times. The above is characterized.

The consolidated propellant of the present invention has a ratio of temporary specific gravities before consolidation and after consolidation of 1.
It is preferably controlled in the range of 0 to 1.18.
If it is increased to 1.18 or more, the Q value obtained from the following formula from the closed bomb test result and the Q value before consolidation are calculated.
It is not preferable because the ratio with the value falls below 90 percent. More preferably, the ratio of temporary specific gravities before and after consolidation is 1.0 to 1.15.

[0009] Where P is the pressure obtained from the closed bomb, t
Indicates time. Further, the ratio of the major axis to the minor axis of the small particles is preferably 1.0 to 2.0, but if it is 2.0 or more, the temporary specific gravity of the small particles themselves becomes small, which raises a problem in that the temporary specific gravity is increased. Further, it is difficult to enter the space formed by the large particles, so 1.0 to 1.5 is preferable.

The ratio of the short axis of the large particles to that of the small particles is preferably 6.0 times or more, and when the ratio is 6.0 or less, separation of particles begins to occur and reproducibility in manufacturing becomes a problem. Also, the temporary specific gravity does not increase. When the ratio of the short axis of the large particles to the small particles is 20 or more, the small particles become too small, which makes it difficult to make them in manufacturing. Further, when the large particles are made large, when they are put in a narrow space, their size becomes an obstacle, and it becomes difficult to increase the amount of propellant loaded. Therefore, the ratio of the short axis of the large particles to the small particles is preferably 20 or less. However, it is difficult to manufacture these single-sized particles, and they may have a distribution.

The content of the small particles is preferably 20% to 80% by weight, and even if it is less than 20% or more than 80%, the temporary specific gravity does not increase. The granular propellant used in the present invention includes a single base (hereinafter referred to as S / B), a double base (hereinafter referred to as D / B), and a triple base (hereinafter referred to as S / B).
(Referred to as T / B) or the like, and any propellant using a polymer that swells in a solvent can be applied. further,
The surface treatment of graphite propellant such as graphite luster is
It is preferable for increasing the provisional specific gravity before the consolidation.

Further, the shape of the granular propellant may be a spherical shape manufactured by an emulsion manufacturing method, a cylindrical shape manufactured by solvent drawing or a solventless drawing, or a prism, and a hole passing through the cylinder or the prism in the machine axis direction may be used. It may be open. For example, as shown in FIG. 1, there are seven holes 1 in the axial direction of a cylindrical propellant grain 11.
It can be a propellant such that 2 penetrates. 7 holes
In addition to the holes, single holes, 19 holes, etc. can be considered. These shapes can be selected according to the requirements of the gas generation pattern.

In the case of a propellant having a hole, the Q value may be reduced as compared with a propellant having no hole, because the hole is crushed by squeezing. Need to raise. The method of consolidation is
The propellant can be swelled using a single solvent or a mixed solvent, and can be pressed using a mold or the like. Also, it can be swelled by contact with solvent vapor or direct contact with liquid, but direct contact swells only in the vicinity of the surface of the granular propellant, and the inside is hard, especially with holes. In this case, it is preferable to swell by direct contact.

Further, it is difficult to control the swelling of the propellant when only the easy solvent of the propellant is used, and it is easier to control the consolidation by using the mixed solvent of the easy solvent and the difficult solvent or the non-solvent. In the case of direct contact, it is preferable to use a mixed solvent. As the easy solvent, a solvent capable of dissolving the granular propellant such as acetone or ether is preferable. As the difficult solvent, a solvent that does not dissolve the granular propellant, such as ethyl alcohol, is preferable. As the non-solvent, those which act as an adhesive such as nitrocellulose are preferable.

After swelling with a solvent, particles are moved and reloaded in a mold and compressed, the packing density does not increase, and pressing is forcibly performed, which impairs performance. Therefore,
It is preferable that the container to be swollen with a solvent and the mold to be pressed are the same, and the container is swollen with a solvent and then pressed. For example,
In the case of swelling with a solvent, as shown in FIG. 2, a mold 25 in which a filter 25 is arranged so as to prevent particles from moving by providing a cock 25 for removing a solvent below the pressing mold 22 is prepared,
The particulate propellant 24 is placed on the filter 23, the solvent is poured from above to swell the particulate propellant 24, the solvent is removed from the cock 25 for removing the solvent, and is squeezed by the squeezing jig 21 from above. be able to.

If a mixture of large particles and small particles is put into a mold at the same time and the closest packing is carried out, it becomes easy to separate on the streaks, and it becomes easy to separate vertically. It is more difficult to separate the large particles from the large particles when the large particles are first put in the mold, then the small particles are put, and the whole mold is vibrated to put the small particles in the space of the large particles.

[0017]

Next, the present invention will be described in more detail by way of examples. In the present invention, large particles and small particles composed of S / B, D / B or T / B were put into a mold, swelled by direct contact with a solvent, and then squeezed to form a consolidate propellant. At this time, swell the propellant in a mold that also serves as a solvent mold for swelling the propellant and a pressing mold for consolidation, and stop contact with the solvent without transferring the swollen propellant and squeeze. Have been consolidated.

As a solvent for swelling the propellant, a mixed solvent of an easy solvent of the propellant and a difficult solvent or a mixed solvent of an easy solvent and a non-solvent was used. Acetone was used as the easy solvent, ethyl alcohol was used as the difficult solvent, and the mixing ratio (weight ratio) was acetone: ethyl alcohol = 20: 80. The mold used had a diameter of 50 mm, and the pressing load was ² Kgf / cm ² .

Tables 1 to 5 show the consolidate propellants prepared by the manufacturing method of the present invention. Tables 1 and 2 show the influence of the large grain minor axis length / small grain minor axis length. T / B was used as the large particle propellant in Table 1, and small particles were used in Example 1,
D / B was used for 2, 4 and 5, and S / B was used for Examples 3 and 6 and Comparative Example 1. Further, S / B was used for the large particle propellant in Table 2, D / B was used for the small particle in Example 9, and
S / B was used in Examples 7, 8, 10, and 11 and Comparative Example 2. The small grain ratio was all 0.4.

[0020]

[Table 1]

[0021]

[Table 2]

In both Tables 1 and 2, Do started to increase from the large particle minor axis length / small particle minor axis length of 6.0 or more, and no separation state was observed, and after consolidation from the closed bomb test. Ratio of the Q value of Q and the Q value after consolidation (Qc
/ Qo) was also 90% or more. The Qc value was measured using a solid propellant having a diameter of about 50 mm and a thickness of about 25 mm, and the Qo value was measured using a granular propellant before molding the solid propellant, using a 700 cc closed bomb device. did.

Tables 3 and 4 show the influence of the small particle ratio. T / B is used as the large particle propellant in Tables 3 and 4,
D / B was used for the small particles. As the molding method and the measuring method, the same methods as in Table 1 and Table 2 were used.

[0024]

[Table 3]

[0025]

[Table 4]

In Tables 3 and 4, when the small particle ratio is 0.2 to 0.8, the specific gravity is large and the Qc / Qo is 90.
% Or more was achieved. Table 5 shows the influence of the major axis length / minor axis length of the small particles. T / B for large particle propellants in Table 5
, And D / B was used for the small particles. The molding method and the measuring method were the same as above.

[0027]

[Table 5]

When the ratio of major axis length / minor axis length exceeds 2.0, the specific gravity before consolidation is reduced, and when the temporary specific gravity after consolidation is increased, Qc / Qo is 90% or less.

[0029]

According to the present invention, it is possible to obtain a consolidate propellant having a high temporary specific gravity and having a gas generation rate substantially the same as that before consolidation. Further, there is no limitation on the composition of the granular combination, and the gas generation rate can be varied. Furthermore, it becomes possible to prevent the instability of the combustion performance due to the separation of large particles and small particles in the cartridge case generated in the mixed particle system by consolidating.

[Brief description of drawings]

FIG. 1 is a view showing a cylindrical propellant used in the present invention.

FIG. 2 is a view showing a mold that also serves as a swelling and swelling mold for the particulate propellant used in the present invention.

[Explanation of symbols]

 11 Cylindrical propellant grain 12 Hole 21 Squeeze jig 22 Squeeze mold 23 Filter 24 Particulate propellant 25 Solvent removal cock

Claims (6)

[Claims] 1. A consolidated propellant using a granular propellant, wherein the granular propellant is composed of two kinds of mixed particles of large particles and small particles, and the ratio of the major axis to the minor axis of the small particles. Is 1.0 to 2.0, and the ratio of the short axis of the large particles to the small particles is 6.0 times or more, a consolidated propellant. 2. The content ratio of small grains is 20% to 8 by weight.
A solid propellant according to claim 1, characterized in that it is 0%. 3. The consolidated launch according to claim 1 or 2, wherein the ratio of the temporary specific gravity before consolidation and the temporary specific gravity after consolidation is controlled to 1.0 to 1.18. medicine. 4. The solid propellant according to claim 3, wherein the granular propellant has a cylindrical shape or a prismatic shape, and through holes are arranged in the machine axis direction. 5. A swelling propellant in a mold that also serves as a solvent container for swelling a propellant and a pressing mold for consolidating, stopping contact with the solvent without transferring the swollen propellant, A method for producing a consolidated propellant, comprising squeezing to form a consolidated propellant. 6. The method for producing a consolidated propellant according to claim 5, wherein the solvent for swelling the propellant is a mixed solvent of an easy solvent for the propellant and a difficult solvent or a non-solvent.