KR960004228B1 - Combustible cartridge case and the manufacturing process - Google Patents

Abstract

The cannon cartridge, perfectly combustible during a firing time of 3/1000 second, replaces the conventional metal one so that it can save the vacant cartridge elimination time, and prevent the manufacturing cost. The method comprises a step of forming a wet solid felt including nitrocellulose, wood fiber, and methyl diphenyl urea; a step of drying the solid felt; a step of dissipating the felt in polyurethane resin for 1-5 minutes; a step of preliminarily solidifying it in the temp range of 40-90 deg.C for 10-50 minutes; and a step of continuously solidifying it in the temp of 90-130 deg.C for 0.2-1.5 hour.

Description

Combustible casings and methods of manufacturing the same

1 is a combined cross-sectional view of a combustible casing according to the present invention,

2 is a perspective view of a combustible container according to the present invention,

3 is an enlarged cross-sectional view in which the rubber ring and the metal base of the combustible casing according to the present invention are combined.

* Explanation of symbols for main parts of the drawings

1: combustible container 2: rubber ring

3: metal base 4: body

5: warhead combination

The present invention relates to a combustible tampy and a method of manufacturing the same, and more particularly, to a combustible casing composed of a composite material that can replace the metal (brass) casing used in large diameter canvas of 105mm or more, and a method of manufacturing the same.

The casing used in the conventional canvas is a metal shell, and the purpose of preventing the high pressure inside the chamber from leaking toward the chamber in the barrel of the warhead has been considered as essential. Since brass used in metal casings is high in price and is a valuable strategic material in key industries around the world, there was a human economic burden to recover and re-use waste casings during the war. In particular, in case of tanks or self-propelled guns, waste casings inevitably generated during warhead firing are stored in a narrow crew room in tanks, and the generation of waste casings and residual gas inside the waste casings have many restrictions on the crew's behavior. As a result, the cabin crew is indispensable for ventilation. In addition, since the metal shell is heavy, it is difficult for the crew to handle, and the rate of firing is reduced by the time it takes to remove the waste shell after the warhead can be a decisive factor in winning or losing. Therefore, even if the metal shells currently used have sufficient functions, waste of manpower and resources is uneconomical in handling, recovering, and regenerating, and there are many obstacles to improving combat power, which is the original purpose of the canvas.

Combustible casings have been proposed to solve the above problems, but conventional combustible casings were manufactured using ABS immersion resin as a reinforcing resin and used by applying moisture proof coating on the surface of the product to reinforce environmental characteristics such as moisture. In addition, the metallic properties such as tensile strength, burst strength, and impact strength, which are the characteristics of resin in combustible casing finished products, are vulnerable, causing problems when handling casings or loading them for actual launch. In addition, the moisture-proof coating process using the organic solvent is required to follow the process such as raw material ratio, coating, and drying, there was a problem of economical due to waste of manpower.

In order to solve these problems, the inventors have conducted extensive research and have found a polyurethane resin that can meet the contrary requirements of high combustibility and the possibility of ignition by heat, and the present invention has been completed based on the above findings. .

Accordingly, it is an object of the present invention to provide a combustible casing that can be used as is without modification of the firing device of current artillery using metal casings.

It is another object of the present invention to provide a method for producing a combustible casing in which the combustible casing can satisfy the contrary requirements of high combustibility and the possibility of ignition by heat, and also consider the effects of environmental changes that may occur during handling. .

It is another object of the present invention to provide a method for producing a combustible casing suitable for canvas characteristics.

Referring to the accompanying drawings, the configuration of the present invention for achieving the above object will be described in detail. The present invention relates to a combustible casing composed of a composite material that can replace a metal (brass) casing used in a large diameter canvas of 105 mm or more, and a method of manufacturing the same. It has a simple casing fixing device so that the casing is not pushed to the barrel by the high pressure generated when it occurs. Otherwise, most of them have a high pressure gas sealing function when looking at the firing device of the canvas. In the case of a canvas having a high pressure gas sealing function in the launch device, the entire combustible casing of the present invention may be composed of the same material having combustibility, but in the case of a canvas having only a simple casing fixing device such as a tank or a self-propelled artillery, FIG. As shown in the figure, it is composed of a combustible container 1 that is completely burned out and extinguishes, a remaining rubber ring 2, and a metal base 3. The combustible casings thus constructed have the same fire effect as the metal casings.

The function of the combustible casing is to fire the warhead coupled to the combustible casing when firing the warhead from the canvas and the combustible casing itself is completely burned, leaving only the metal base 3 combined with the rubber ring 2 in the muzzle chamber. It is gone. In actual warhead firing, the propellant in the shell casing combusts and the time it takes for the warhead to leave the muzzle is about 3/1000 seconds and the combustible shell shell must be burned in the chamber of the artillery for such a short time. In other words, a combustible casing fires a warhead and requires a high combustion characteristic that must be completely combusted in the chamber and, in the event of a residue, must be completely discharged from the interior of the chamber together with high pressure exhaust gas.

On the other hand with the above-mentioned satisfaction, the combustible casings on the other hand have to be excluded as much as possible in the case of contact with cigarette fires, hot cloth chambers, etc., or when exposed to strong sunlight, i.e., the possibility of ignition by fire or heat. It has requirements that conflict with the combustion characteristics.

Hereinafter, the composite composition of the combustible casing in consideration of the above conflicting requirements and environmental changes that may occur during handling will be described in detail. Table 1 below shows the basic composition of the raw materials constituting the combustible container of the casing. Hereinafter, "%" means "% by weight".

TABLE 1

1) combustion promoting fiber

Nitrocellulose (NC) is used to have the high combustibility required by the casing in the composition of the combustible casing. The NC has a nitrogen content of 1.25% to 13.45% and a fiber length of 0.4mm to 1.0mm and a cotton linter. NC which is superimposed on) is used. NC is used for the body of combustible casings, but not for warhead joints.

2) structural fiber

As shown in FIG. 2, the kraft pulp is used as the fiber for the skeleton of the body 4, and the NC is not used for the warhead assembly 5, which requires more metallic properties than combustibility. In some cases, wood fiber is used. The wood fibers may be ground wood pulp, refiner groundwood, and threaded wood. Preferably, the wood fibers have a shredded wood having more than 95.5% of wood. Is used. The kraft pulp includes chemi-groundwood pulp and chemical pulp. Preferably, the kraft pulp is chemical pulp, and the length of the kraft pulp is 2 mm to 5 mm.

3) Reinforcing resin

Polyurethane-based resins are used as reinforcing resins in which the combustible casings have metallic properties, and the polyurethane-based resins include one-component and two-component types, and preferably two-component types. To enhance the environmental characteristics of combustible casings, additives such as Multron R-221-75 and Baysilone Fluid PL from Mobay Chemical, USA are used. Disks, which are contained inside the combustible casings during the assembly of coal, are made of acrylonitrile butadien styren (ABS) resin.

4) NC stabilizer (Methyl dephenyl urea)

Diphenylurea is used to have chemical stability during or during storage of combustible casings containing NC. The content of NC stabilizer in the composition of combustible casings is determined within the range that satisfies the stability of the final product and the test requirements. A common stability test is the methyl violet test conducted at 135.5 ° C.

Hereinafter, a method of manufacturing a combustible casing will be described.

As described above, it can be said that the resin deposition method is the main part of the manufacturing process as producing a combustible casing suitable for the canvas characteristics with the members of the present invention.

As shown in FIG. 2, nitrocellulose, kraft pulp, wood fibers, methyldiphenylurea are attached to the stirrer to produce a wet felt having the shape of the body 4 and the warhead binder 5. A slurry is prepared by mixing with water in the tank. The slurry is dispersed in water as evenly as possible and the concentration of solids in the slurry is 0.3% to 0.7%. When the concentration of the solid content is 0.3% or less, a phenomenon in which the time required for forming the felt during the production of the wet felt is long, and when it is 0.7% or more, the uniformity of each part of the wet felt is inferior.

In the next process, a wet felt having the same shape as the body 4 and the warhead combination 5 is manufactured. Here, a wet felt is manufactured by adsorbing solids in the slurry onto a felting mold using a felting mold covered with a gold net or stockings and a 700 mmHg vacuum in a felting tank containing slurry. The content is about 50% to 65%. If more than 65% of the wet felt has a disadvantage in that a lot of time to dry in the compression and drying process.

Next, the pressing mold and the hydraulic press are used to simultaneously compress and dry the wet felt, and the produced product has the same shape as the final product. Compression molds are combined with female and metal molds and use steam of 2kg / cm 2 to 3.5kg / cm 2 and vacuum of 680mmHg. The mold temperature is 110 ℃ ~ 130 ℃. If the pressure condition is 2kg / ㎠ or less, the temperature of the mold becomes 110 ℃ or less, and the crimping felt is not dried, so it tends to be damaged during handling. If the pressure is 3.5kg / ㎠ or more, the mold temperature is too high and the pressing ends. At the same time, there is an increase in the burning characteristics, which leads to a safety risk.

The next step, which is the center of the manufacturing method of the present invention, is to deposit the dried molded product in the above step in the polyurethane-based resin and then to harden to give the combustible casing a metallic characteristic. The basic method of the resin occurs at this time is as follows.

Where R is an alkyl group, R 'is another alkyl group and n is the degree of polymerization.

Polyurethane resin used in the present invention is used by diluting in organic solvents such as dimethylformamide, xylenes, and tetrahydrofuran, triethylamine as a catalyst for promoting the reaction. ) And triethylenediamine and the like. The compressed and dried product is sufficiently immersed in the resin mixed organic solvent solution for 1 to 5 minutes, and then the dried product is cured by drying hot air. The curing is precured for 10 to 50 minutes at the first 40 ℃ to 90 ℃ and then the main curing is continuously progressed for 0.2 to 1.5 hours at the second 90 ℃ to 130 ℃ to complete the curing work. The reason for the main curing is to separate and harden the primary and secondary hardening to prevent sudden volatilization of the organic solvent, and when the main curing is out of the above temperature range, the curing time becomes long or a problem occurs in stability.

As shown in FIG. 3, the present invention is characterized in that the rubber ring 2 and the metal base 3 are designed to enable the use of a combustible casing without modification of the current canvas generator using the metal casing. It is in the combination principle of. The rubber ring (2) serves to block the leakage of the hot, high-pressure gas formed in the muzzle with the muzzle after the firing of the propellant and the combustible vessel in the case of carbon firing by supporting the metal base (3). The material used for the rubber ring (2) is a hydrogenated nitrile rubber or silicone rubber having a slight thermoplasticity withstanding high temperature and high pressure gas, and a silicone rubber. It has a width of 1/15 to 1/6 of the total length of the combustible body. At this time, there is a problem that the propellant combustion gas is leaked toward the chamber when out of the range. The metal base uses inexpensive steel alloy and the length is preferably about 1/14 to 1/6 of the combustible container body in consideration of handling.

The rubber ring 2 and the metal base 3 are joined by a method of forcibly fitting the rubber ring to the joint section of the metal base specially designed in the present invention.

The following Examples further illustrate the spirit and effect of the present invention in more detail, but do not limit the scope of the invention.

Example 1

First, nitrocellulose, kraft pulp, wood fiber, methyldiphenylurea were attached to the stirrer in Table 2 to prepare a wet felt having the shape of the body 4 and the warhead binder 5. Slurry was prepared by mixing with water in the tank to bring the concentration of solids in the slurry to 0.5%.

Next, in order to manufacture a wet felt of the same shape as the body 4 and the warhead combination 5, a slurry using a 700mmHg vacuum and a felting mold covered with a gold net or stockings in a felting tank containing the slurry. The solid content in the sample was adsorbed onto a felting mold to produce a wet felt, and the moisture aroma of the wet felt was 60%. Then, the crimping mold and the hydraulic press were used to simultaneously compress and dry the wet felt. At this time, the compression mold was combined into a female and a mold, using a steam of 3kg / ㎠ and a vacuum of 680mmHg and the temperature of the mold was 120 ℃. The dried molded product in the process was immersed in a polyurethane-based resin for 3 minutes and then cured. The curing was precured at 70 ° C. for 30 minutes and then continuously cured at 110 ° C. for 1 hour. A combustible container was prepared and a combustible casing of the present invention was prepared by adhering a rubber ring and a metal base to the combustible container. Combination of KE warheads with combustible casings manufactured by the above method was conducted in a 120mm tank gun at a chamber pressure of 5,100 bar and a warhead firing speed of 1703 m / s (1.706 m / s when firing a metal shell). No residue was found at, and the deviation of the warhead's firing rate and impact point was also very good. Table 3 below describes the specifications of combustible casings produced by the method.

Example 2

It was prepared in the same manner as in Example 1 except that the composition described in Table 2 and the specifications described in Table 3 below. Combination of HEAT warheads with combustible casings manufactured by the above method was carried out in a 120mm tank gun at a chamber pressure of 4,800 bar and a warhead firing speed of 1,140 m / s. No residue was found in the chamber. The variation of the firing speed and the impact point of the was found to be very good.

TABLE 2

TABLE 3

Claims (2)

A method for producing a wet felt of a slurry solid content containing a continuous promoting fiber, a structural fiber, and a nitrocellulose stabilizer, and drying and molding the same to produce a combustible casing, wherein the dried and molded product is subjected to polyurethane resin for 1 to 5 minutes. The method of producing a combustible casing, characterized in that it is deposited for a period of time, first cured at 40 to 90 ° C. for 10 to 50 minutes, and then continuously cured at 90 to 130 ° C. for 0.2 to 1.5 hours. Combustible casings produced by the method of claim 1.