Novel self-locking type cartridge case capable of preventing primer from impacting and falling off

Abstract

The invention discloses a novel self-locking cartridge case capable of preventing a primer from impacting and falling off, and belongs to the field of cartridge cases. From the perspective of engineering development requirements and application, the invention provides a primer chamber structure scheme for preventing the primer from impacting and falling off on the basis of an existing bullet shell primer chamber structure. Different from a conventional bullet primer chamber, a plurality of annular grooves are formed in the inner wall of the novel primer chamber structure. After the propellant powder is ignited, gunpowder fuel gas acts on the primer shell through the flash hole, and under the locking limitation of a gunlock at the bottom of the primer, the primer shell is plastically deformed to be embedded into the annular groove and is embedded and locked with the interior of the primer chamber by utilizing the characteristic that brass is easy to plastically deform, so that the impact falling of the primer is limited.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of shell, and particularly relates to a novel self-locking shell capable of preventing bottom fire impact from falling off. BACKGROUND

[0002] A light weapon bullet mainly comprises a bullet head, a shell, a primer and a propellant, the primer comprises a primer shell, a percussion powder, a paper cover and a fire platform, and the structure is as shown in Figure 1 and Figure 2 The primer shell and the fire platform are made of H68 copper and are cold-stamped to have strong corrosion resistance and aging resistance. The primer comprises a Boxer primer and a Berdan primer, and the Berdan primer does not comprise a fire platform structure. The whole primer is pressed into the primer chamber through interference fit by using a die tool.

[0003] The bullet firing principle is as follows: the bottom of the primer is deformed by the impact of the firing pin, the percussion powder between the fire platform and the bottom of the primer shell is extruded to reach the ignition hot spot, the flame of the burning percussion powder enters the shell through the shell transfer hole to ignite the propellant, and the ignition and transfer functions of the primer are completed. After the propellant is ignited, a large amount of high-temperature and high-pressure propellant gas is generated, the bullet head is extruded into the gun barrel rifling under the load of the propellant gas, a sealed environment is formed, and the bullet head completes the accelerated rotary motion under the load of the propellant gas until it flies out of the muzzle.

[0004] In the development process of high-performance bullets, in order to cope with the threat of enemy firepower in future battlefield, form firepower suppression on the enemy, it is necessary to improve the kinetic energy and long-distance penetration power of the bullet, and to adopt the way of increasing the bullet charge and high-energy density propellant to carry out bullet interior ballistic design research, so as to achieve greater chamber pressure (and muzzle velocity) of the bullet. However, the interference fit of the primer and the primer chamber has limited force, and the primer is very easy to fall off during the firing process under the impact of high chamber pressure, which causes shooting failure, especially affecting the function of bullet / gun match continuous shooting.

[0005] In view of the technical problem of primer falling off of the bullet, on the one hand, the primer falling off problem can be solved to a certain extent by reducing the diameter of the primer chamber and increasing the interference fit between the primer and the primer chamber. On the other hand, the technology of increasing the hardness of the primer chamber and matching the primer and the primer chamber by point riveting to increase the bonding force between the primer and the primer chamber is relatively close to the present patent. However, the technical scheme of increasing the hardness of the primer chamber and the interference amount has limited effect on the force between the primer chamber and the primer, and can only solve the primer falling off failure under a certain pressure, and has little effect on the primer falling off failure under higher pressure. In addition, the point riveting technology is only applicable to the matching between the copper shell and the primer, and cannot be applied to the painted steel shell. Therefore, the existing technology cannot be applied to higher performance bullets. SUMMARY

[0006] To address the above technical issues, the present invention proposes a novel self-locking cartridge case that prevents primer impact and dislodgment. The cartridge case's primer chamber structure is provided with n circumferential grooves. After firing, chamber pressure load P acts on the primer housing through the firing port at the bottom of the cartridge case. When the bolt is locked, the brass shell of the primer undergoes plastic deformation and embeds itself into the circumferential grooves of the primer chamber. The primer deforms under the pressure load P and the interaction force.

[0007] The cartridge case is arranged on a bullet structure, and the bullet structure comprises a bullet head, a cartridge case, propellant and a primer chamber at the rear of the cartridge case.

[0008] When the bullet is fired, the gunpowder gas load generated by the combustion of the propellant acts on the primer shell through the spark hole. The plastic deformation characteristics of brass H68 cause the primer structure to undergo plastic deformation and embed into the annular groove of the primer chamber, thereby reducing the shedding of the primer.

[0009] After the propellant is ignited, the gunpowder gas acts on the primer shell through the fire transfer hole. Under the locking restriction of the bolt at the bottom of the primer, the plastic deformation characteristics of brass H68 are utilized to plastically deform the primer shell and embed it into the annular groove, embedding and locking it with the inside of the primer chamber to limit the impact and shedding of the primer.

[0010] In summary, based on the needs of engineering development and application, this invention proposes a primer chamber structure that prevents primers from impacting and falling out, building on the existing structure of a cartridge case primer chamber. Unlike conventional cartridge primer chambers, this novel primer chamber structure features several annular grooves on its inner wall. After the propellant is ignited, the gunpowder gas acts on the primer shell through the ignition holes. Under the locking restriction of the bolt at the bottom of the primer, the primer shell, utilizing the plastic deformation properties of brass, undergoes plastic deformation and embeds into the annular groove, locking it with the interior of the primer chamber and preventing the primer from impacting and falling out. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0012] Figure 1 It is a schematic diagram of the bullet structure in the prior art.

[0013] Figure 2 It is a schematic diagram of the relationship between the primer, primer chamber and interference fit in the prior art.

[0014] Figure 3 It is a schematic diagram of the structure of the primer chamber of a bullet in the prior art.

[0015] Figure 4 The schematic diagram of the new primer chamber structure according to the embodiment of the present application.

[0016] Figure 5 The schematic diagram of the state after the primer is pressed into the primer chamber according to the embodiment of the present application.

[0017] Figure 6 The schematic diagram of the force state of the primer during the firing process of the cartridge according to the embodiment of the present application.

[0018] Figure 7 The schematic diagram of the matching of the primer and the primer chamber after the cartridge is fired according to the embodiment of the present application.

[0019] Figure 8 The schematic diagram of the cartridge structure according to the embodiment of the present application.

[0020] Figure 9 The schematic diagram of the cartridge primer assembly state according to the embodiment of the present application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0022] Abbreviations and key terms definition:

[0023] High bore pressure: the bore pressure performance of the active cartridge is ≤330 MPa. Here, high bore pressure generally refers to a pressure higher than 350 MPa.

[0024] Bolt lock: after the cartridge is fed into the bore of the firearm, the bottom of the cartridge is stopped by the bolt, so that the cartridge is completely sealed in the bore.

[0025] The reasons for primer falling off include: the wall strength of the primer chamber is insufficient, improper force is used during the riveting and stamping process of the primer chamber, which causes the deformation of the primer chamber, and under the action of high bore pressure gas, the smoke leakage phenomenon occurs; in severe cases, plastic deformation of the primer chamber occurs, forming a gap, which leads to primer falling off;

[0026] The size and shape of the primer chamber are incorrect, which leads to poor matching, existence of a matching gap or small interference, inability to seal the gas, and primer falling off and smoke leakage phenomenon under the action of high bore pressure.

[0027] The solutions include, for example: Figure 3As shown, the technical scheme for solving the primer falling off by increasing the bonding force between the primer and the primer chamber is given, the hardness of the primer chamber of the shell is improved, the shell heat treatment process parameters are optimized, and the consistency of the stamping process parameters is strictly controlled during the stamping of the primer chamber to ensure the stable stamping forming of the primer chamber. By optimizing the processing technology of the primer chamber, the hardness of the primer chamber is improved, and the hardness of the primer chamber before and after optimization is compared in Table 1.

[0028] Table 1: Comparison of primer chamber hardness before and after optimization

[0029] Status Hardness of the primer chamber (HV 2.5 )]]> Before 165 After 180

[0030] The increase of the interference fit of the primer can increase the bonding force between the primer and the shell, which is beneficial to solve the problem of primer falling off. However, if the interference fit of the primer is too large, the firing performance of the primer will be reduced. Through multiple scheme comparison, the interference fit of the primer is determined. The interference fit of the primer before and after optimization is shown in Table 2.

[0031] Table 2: Interference fit of primer before and after research

[0032] Status Firing pin insertion interference (mm) Before +0.04～+0.13 After +0.06～+0.15

[0033] This way of improving the primer falling off phenomenon by increasing the bonding force between the primer and the primer chamber has been adopted and implemented by the majority of gun and bullet research and development design and production units. However, this technology can only reduce the primer falling off phenomenon of conventional performance bullets under a certain chamber pressure, and has little effect on the primer falling off phenomenon of bullets under high chamber pressure. There is a high probability that the primer falling off phenomenon will continue to occur.

[0034] From the perspective of engineering research needs and application, a primer chamber structure scheme for preventing primer impact falling off is designed based on the existing gun shell primer chamber structure. Unlike the conventional primer chamber, the new primer chamber structure is provided with a plurality of annular grooves on the inner wall. After the propellant is ignited, the propellant gas acts on the primer shell through the transfer hole. Under the locking restriction of the primer at the bottom of the bolt, the primer shell plastically deforms and embeds into the annular groove, and is locked with the primer chamber, thereby limiting the impact falling off of the primer.

[0035] As shown in the new primer chamber structure, Figures 4-6 on the basis of the existing conventional shell primer chamber structure, n annular grooves are provided. When the bullet is fired, the chamber pressure load P acts on the primer shell through the primer hole at the bottom of the shell. Under the locking state of the bolt, the primer brass shell plastically deforms and embeds into the annular groove in the primer chamber. Finally, under the pressure load and interaction force, the primer achieves the deformation effect as shown in Figure 7 .

[0036] As shown in the new primer chamber structure, Figure 8As shown in the schematic diagram of the bullet structure, 1 is a bullet head, 2 is a shell, 3 is a propellant, and 4 is a primer. Figure 9 As shown in the schematic diagram of the primer and primer chamber assembly structure, when the bullet is fired, the propellant gas load generated by the combustion of the propellant acts on the primer shell through the transfer hole. Because brass H68 is easy to deform plastically, the primer shell plastically deforms and embeds into the annular groove in the primer chamber, thereby achieving the purpose of reducing primer shedding.

[0037] Compared with the prior art, the technology of the present application can significantly reduce the primer shedding phenomenon during the bullet firing process under high bore pressure (above 350 MPa), ensure the reliability of bullet / gun matching continuous firing, and also be beneficial to the research and development design of high bore pressure and high initial velocity performance bullets.

[0038] Please note that the technical features of the above embodiments can be combined in any way. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combination of the technical features does not exist contradictory, it should be considered as the scope of the present application. The above embodiments only express several implementation ways of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of the present application. Therefore, the scope of the patent of the present application should be subject to the appended claims.

Claims

1. A new type of self-locking cartridge case that is resistant to primer impact and shedding, characterized by: The primer chamber structure of the cartridge case is provided with n annular grooves; after the bullet is fired, the chamber pressure load P acts on the primer shell through the fire transfer hole at the bottom of the cartridge case; when the bolt is locked, the brass shell of the primer undergoes plastic deformation and embeds into the annular groove of the primer chamber, and the primer is deformed under the pressure load P and the interaction force.

2. The novel self-locking cartridge case that is resistant to primer impact and shedding according to claim 1 is characterized in that: The cartridge case is arranged on a bullet structure, and the bullet structure comprises a bullet head, a cartridge case, propellant and a primer chamber at the rear of the cartridge case.

3. The novel self-locking cartridge case that is resistant to primer impact and shedding according to claim 2, characterized in that: When the bullet is fired, the gunpowder gas load generated by the combustion of the propellant acts on the primer shell through the spark hole. The plastic deformation characteristics of brass H68 cause the primer structure to undergo plastic deformation and embed into the annular groove of the primer chamber, thereby reducing the shedding of the primer.

4. The novel self-locking cartridge case that is resistant to primer impact and shedding according to claim 3 is characterized in that: After the propellant is ignited, the gunpowder gas acts on the primer shell through the fire transfer hole. Under the locking restriction of the bolt at the bottom of the primer, the plastic deformation characteristics of brass H68 are utilized to plastically deform the primer shell and embed it into the annular groove, embedding and locking it with the inside of the primer chamber to limit the impact and shedding of the primer.

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