The invention relates to the technological development for weapon, gunpowder, electromechanical hardware and software of embedded devices, and in particular relates to the automatic control of weapon, the use of liquid gunpowder and the related technology of the caseless weapon.
Nowadays, the bullets used by firearms and small caliber guns are in a form that the projectiles and shells are packed in one, and in this form, the role of the shells is indispensable. Shells pack the propellant powder and primer, wrap the projectiles, seal the bore and take away part of the heat for cooling. However, the shells also have many drawback, such as: copper shells caused a huge waste of resources; shells accounted for half of the weight of bullets, limiting the amount of ammunition that soldiers to carry; the ejection of the shells and the demand for left and right switching makes the structure of the firearms more complicated.
In the case of NATO's 5.56×45 mm caliber ammunition, the weight of the bullet is about 11.8 g, and the weight of the projectile is about 4.02 g (62 gr), the weight of shell is about 6.16 g (95.1 gr), and the weight of the powder is roughly around 1.6 g (24.5 gr). It could be seen that the weight of the bullet is 52.2% occupied by the shell. In the case of a soldier battle fighting, the maximum amount of the ammunition to carry is around 10 kg. Considering the weight of the magazine, a soldier could carry about 660 rounds of 5.56 mm of bullets, with a total weight of about 7.8 kg, and 4.06 kg are shells weight.
Due to the existence of shells, the relevant weapons must perform shell ejection actions. For most of the firearms, they are using the right-side shell ejection design. The high temperature shells not only interfere with the comrades around, but also cause greater trouble for left-handed shooters, and this trouble will be more prominent in those Bullpup firearms, many firearms had to be designed to have a structure that could switch the side of shell ejection.
In addition to the trouble caused by high-temperature copper shell, due to the short distance between the shell ejection window and the shooter, the gunpowder smoke and residual gas will also bring some troubles to the shooter.
The solid gunpowder firearms have been invented for hundreds of years, the current large-scale equipped of the firearms are based on machinery and gunpowder. In order to meet the needs of semi-automatic or automatic shooting, most of the modern firearms are using the energy of combusted gas to complete the shell ejection and loading; however, it is difficult to accurately estimate the energy of combusted gas for completing the next cycle. In order to meet the reliability requirements, it could only excessively use gas energy to complete the shell ejection and loading in a very violent way. This will reduce the efficiency of gunpowder consumption, but also affect the accuracy of shooting. Due to the limitations of the mechanical structure, it is difficult perform both fully automatic shooting and high precision sniping on one single firearm, in order to meet high shooting precision, the current sniper rifle had to use the bolt structure or semi-automatic structure.
Nowadays liquid gunpowder has been widely used in mining, marine engineering operations, military engineering blasting and special engineering blasting areas. Liquid gunpowder has several of advantages, such as high mobility, high explosion temperature, high energy/volume ratio and safety. Among all kinds of liquid gunpowder, a binary non-spontaneous combustion liquid gunpowder, which consists an oxidizer and a fuel, is very suitable for firearm's safety requirements, the combustible explosive liquid can only be formed when both components of the binary liquid gunpowder are injected into the combustion chamber. The oxidizer of the binary liquid gunpowder could be nitric acid, dinitrogen tetroxide, hydrogen peroxide, and ammonium pernitrate (N2H4O4) and so on. The fuel could be decahydronaphthalene, kerosene (JP4), isooctane and isopropanol (IPA). Liquid fuel has characteristics as such low viscosity, easy to atomize, small atomization diameter, easy to be mixed, burned and evaporated. In addition, the volume of liquid fuel is relatively stable with temperature changes; the flow rate can be precisely controlled in order to meet the requirements of the internal ballistic stability.
Liquid gunpowder has good fluidity, so liquid gunpowder is able to be injected into the combustion chamber by pressure to complete the loading of the gunpowder. For armored vehicles or other mechanized vehicles with sufficient power supply, the liquid powder can be loaded at atmospheric pressure, and then be propelled to the pressure regulator through the high-pressure pump. The fuel and oxidizer are stored separately; this storage method can improve the safety and greatly avoid the occurrence of ammunition's accidental explosion. In addition, the liquid itself has a high specific heat and good thermal conductivity, this characteristic has a very good effect on the cooling of combustion chamber, which is able to effectively prevent the combustion chamber and casing part to overheat.
The function of the Electronic Fire Control Unit (EFCU) is very close to that of the engine control unit (ECU) used by the car, and regarding the requirement of reaction speed, the firearms are far less demanding of EFCU than the engine is to ECU. Refer to the performance of today's mainstream individual firearms, in the automatic fire mode, fire rate of 400˜900 rounds/minute could meet the needs of the battlefield; in the multi-burst fire mode, the fire rate of 80˜120 rounds/minute could meet the demand. Through the microcontroller, memory, power module, digital-analog conversion module, it will be very easy to meet the needs of the electronic fire control unit (EFCU) for weapon system. Combined with switching devices, sensors, solenoid valves, indicator lights and servo motor, it will be fully achievable to make a liquid gunpowder based caseless weapons.
Based on the limitations of today's artillery and ammunition, the present invention provides an approach to build a liquid gunpowder based caseless weapons, with which the amount of ammunition carried by combat personnel under the same load conditions can be greatly improved, and is able to meet the requirements of shooting accuracy and firepower at the same time, in addition, such weapons systems will greatly save the consumption of precious metals such as copper, as a result to make shooting costs greatly reduced.
The present invention proposed a method to achieve the caseless ammunition firing with liquid propellant for a class of automatic weapon. A weapon with this method is driven by a servo motor that led a slider for linear reciprocating motion, and then the slider drive a combustion chamber and rotary lock to complete the projectile filling and combustion chamber locking. The combustion chamber locking was achieved with the help of a fixed plunger. Separated binary liquid gunpowder (oxidizer and fuel) are used as propellant. Liquid propellant injection pressure was maintained by a constant pressure regulator; and an electronic fire control unit (EFCU) precisely controlled solenoid valves opening time in order to control injection dose of the mixture. Gunpowder is injected through two nozzles on the fixed plunger, and be ignited by an electronic igniter to achieve the projectile launching.
The loading of the projectile.
The leakage issue of the liquid propellant.
The air tightness of the bore and combustion chamber.
Timing coordination between the locking of combustion chamber, the injection of liquid propellant and the ignition.
The combustion chamber (3), as a moving part inside a sleeve of cartridge receiver (2), performed linear reciprocating motion along the axis of the bore. a cone-shaped end (14) of the combustion chamber has a triangular fin. when the cone-shaped end (14) moved back and positioned completely rear of magazine opening (15), a projectile will be pushed by magazine spring into the space where a combustion chamber (3) doing reciprocating motion, when the combustion chamber (3) moved in the direction to barrel's bore (16), a triangular fin (17) on the cone-shaped end (14) will push the projectile out of feed lips (18) of the magazine (31) with certain speed, the projectile will be pushed along projectile guidance groove (19) into female cone (20) section of the bore, through self-guided ability of the female cone (20), the projectile will enter automatically into the bore under the pushing force of the cone-shaped end (14) to complete the loading.
Fuel and oxidizer of the liquid propellant can be pressurized and stored by means of a pressure vessel, in the moment after the trigger is triggered, the propellant is injected into the combustion chamber (3) and then complete ignition, the presence of liquid propellant in the combustion chamber (3) is only a transient, it makes the leakage of liquid gunpowder to be avoided.
The gastight sealing of the combustion chamber (3) and the bore (16) is achieved by their conical surfaces touching; the combustion chamber body (21) and its cone-shaped end are made with different materials. The main body of the combustion chamber (3) is made of high strength material; the cone-shaped end (14) is made of high elastic material, and its high elasticity made the cone-shaped end is easy to deform under high pressure, which improves gas tightness between the bore (16) and the combustion chamber (3); there is a gear-shaped rotary lock (4) at the tail of the combustion chamber, inside the cartridge receiver, there are corresponding teeth (22); rotary lock teeth (22) and the sleeve of cartridge receiver teeth (22) are shaped in wedge, by rotating of the rotary lock (4), combustion chamber (3) can be pushed as close as possible to the bore (16), so that the cone-shaped end (14) and the female cone (20) of the bore can fit closely.
For the design of cylindrical cam (11) has a straight cam path (23) which is perpendicular to camshaft (12), when a cam pin (24) of the slider (9) moves in this straight cam path (23), a slider (9) is in a relatively static state to the cartridge receiver (2) even if the cylindrical cam (11) continues to rotate, while the combustion chamber (3) is also in the Lockout state. In the full auto fire mode, the cylindrical cam (11) will rotate continuously without interruption. The EFCU determines the cylindrical cam (11) position by the angular displacement of the servo motor and complete the propellant injection and ignition each time the cam pin (24) of the slider (9) travels in the straight cam path.
The present invention provides an approach to build a liquid gunpowder based caseless weapons, with which the amount of ammunition carried by combat personnel under the same load conditions will be greatly improved, and will meet the requirements of shooting accuracy and firepower at the same time, in addition, such weapon systems will greatly save the consumption of precious metals such as copper, as a result to make shooting costs greatly reduced.
The present invention will now be described in detail with reference to the appendix figures and specific examples thereof in order to make the objects, technical solutions and advantages of the present invention more apparent.
The main embodiment process of the method provided by the invention comprises the following steps:
Refer to the relevant parameters of the NATO 5.56 mm caliber ammunition, this embodiment is based on a Bullpup assault rifle design that uses a 508 mm (20 in.) in length heavy barrel (1) with a 5.56 mm caliber. The assault rifle can be used for precise sniping and full auto shooting, to meet the needs of most of the field and street battle, the Bullpup structure will also be suitable for using in space cramped vehicles.
The main mechanical parts of the rifle as shown in
In the main mechanical parts given above, the barrel (1), the combustion chamber (3), the rotary lock (4), the guide pin (5), the retaining ring (6), the plunger (7) and the positioning pin (13) are made of steel, and the other parts could be manufactured all in 6061-T6 aluminum alloy,
In the present embodiment, the battery is energy source, and the servo motor is used to drive the cylindrical cam (11). The cylindrical cam (11) drives the slider (9) to make reciprocating motion in the rail bracket (10). The slider (9) is then acted on the guide pin (5), which bring rotary lock (4) to make reciprocating motion along the L-shaped guide groove (25) on the sleeve of cartridge receiver (2), and ultimately achieve the cycle process of projectile loading and locking. In this case, the sleeve of cartridge receiver (2) and the rail bracket (10) are machined separately, and the sleeve of cartridge receiver (2) is machined with a positioning groove (26) in order to be mounted on the rail bracket. The rail bracket (10) could be assembled with the sleeve of the sleeve of cartridge receiver (2) by means of welding or riveting to form the whole cartridge receiver. The relationship between the moving parts are shown in
The barrel (1) and the sleeve of cartridge receiver (2) could be threaded, they could also be connected with fast plug-in method, the positioning pin (13) could ensure that the installation is properly done. The base of the barrel is the bore (16), the apex angle of the cone needs to be in a suitable range, to ensure that the tip of the projectile is able to smoothly enter into the guide range of the conical bore, in the present embodiment, this apex angle of the cone is about 40 degrees. Projectile loading process is shown in
In the case of ensuring the strength, the combustion chamber (3) has to be as light as possible to reduce inertia, it will improve the firing rate of weapons. The working volume of the combustion chamber (3) is determined by the position of the projectile and the plunger (7), and the volume size of the combustion chamber (3) needs to be considered in numerous ways, and ultimately it needs to be determined experimentally. The high-strength combustion chamber allows weapons to be used with higher intensity, and burning gunpowder with higher explosive rate. The radius of combustion chamber gas outlet (27) needs to be slightly larger than the projectile tail radius, but must be less than the maximum radius of the projectile. The relationship between bore, combustion chamber (3) and projectile are shown in
In the present embodiment, the combustion chamber (3) is made of steel and copper, in which the main body of the combustion chamber (3) is made of steel, and the front end of the combustion chamber is made of copper. Under the strong explosion pressure, the copper will show good ductility and elasticity, cone-shaped end (14) of the combustion chamber (3) will be slightly deformed and be better fitted with the female cone (20) of the bore, in order to achieve good air tightness, but also to prevent the tip of the cone be cracked under the pressure of explosion.
In the present embodiment, the rotary lock (4) and the sleeve of cartridge receiver (2) each has six teeth (22) uniformly distributed around the circumference, and the locking angle is 30 degrees. When the rotary lock was rotated by 30 degrees along a L-shaped guide groove (25) on the sleeve of the cartridge receiver (2), the rotary lock's teeth (22) will overlap with the teeth (22) on the sleeve of the cartridge receiver (2) to complete the combustion chamber lockout. rotary lock teeth (22) and the cartridge receiver teeth (22) are shaped in wedge, by rotating of the rotary lock (4), the interaction between the wedge surfaces can push the combustion chamber (3) as close as possible to the female cone (20) of the bore, so as to ensure air tightness and to prevent the fragile front tip of the combustion chamber be cracked due to lack of support from the female cone (20) of the bore, at the same time it is able to reduce the requirements of mechanical accuracy and assembly accuracy. The relationship of the rotary lock (4) and sleeve of cartridge receiver (2) is shown in
In the present embodiment, the slider (9) and the cylindrical cam (11) each have a helical groove (28) and at a 45 degree helix angle with the respective central axes, the guide pin (5) and the cam pin (24) of the slider slide in their respective groove. In the case of a slider (9), a 45 degree helix angle is able to ensure that the distance traveled by the slider (9) is equal to the arc length of the guide pin (5) traveled in the L-shaped guide groove (25) of the sleeve of cartridge receiver (2). The cylindrical cam (11) is driven directly by the servo motor, and the helical groove (28) of the cylindrical cam (11) interacts with the cam pin (24) of the slider (9) while the cylindrical cam (11) rotating to cause the slider (9) to reciprocate along guidance rail (43) of the rail bracket. The path of the cam is shown in
It could be seen from
The height of the cam path curve Hc is determined by three parameters, which are the distance of the cone tip of the combustion chamber extending into the female cone (20) base of the bore Lo, the diameter (or width) of the magazine's feed lips (18) Dm and the length of the 30 degrees locking angle arc La that is travelled by the guide pin (5) along the sleeve of cartridge receiver (2) when the combustion chamber (3) is locked. Therefore, Hc=Lo+Dm+La, (note that the helix angle of the helical groove is limited to 45 degrees).
The cam path's straight section A-B occupies a quarter of the circumference, helical groove's helix angle is 45 degrees, therefore, the cylindrical cam (11) diameter Dc=8Hc/3π
The distance travelled by the combustion chamber (3) Lc is: Lc=Lo+Dm
The EFCU needs to determine the timing of the gunpowder injection and the ignition by the angular displacement of the servo motor. The position and direction of movement of the slider (9) can be uniquely determined by the angle and direction of rotation of the cylindrical cam (11), the position and the moving direction of the rotary lock (4) as well as the combustion chamber (3) can be uniquely determined by the position and direction of the slider (9). So as long as the timing of the assembly between the servo motor and the cylindrical cam (11) is determined, the time requirements of the whole system can be solved. As shown in
The plunger (7) is a relatively important part of the system, the plunger (7) has to withstand the high temperature and high pressure produced by the explosion in order to provide the gas tightness to the combustion chamber (3), it also needs to accommodate the ignition device and be the nozzle of the liquid gunpowder. As shown in
Valve seat (8) could be made of 6061-T6 hard aluminum alloy, valve seat has to withstand the high pressure passed from the plunger (7), but also plays the role of connecting solenoid valves and plunger, as shown in
The fuel and oxidizer of the liquid propellant may be pressurized and stored by means of a pressure vessel and then connected by means of a quick plug joint to firearm. The liquid fuel and the liquid oxidizer will each pass through a separate conduit into the respective pressure regulator, and finally get a constant pressure through the pressure regulator and then be injected into solenoid valves.
In the present embodiment, the liquid propellant is mixed until it enters the combustion chamber, thereby ensuring the safety of such weapons.
Considering existing technology, the using of pressure vessels to supply of liquid propellants for individual weapons is quite realistic. Take 5.56 mm ammunition as an example, the shell charge is about 1.5 g gunpowder, the volume is 1.85 ml, considering that the liquid gunpowder energy/volume ratio is higher than the solid gunpowder, and the present weapon system has a higher gunpowder consumption efficiency, so the use of 450 ml pressure bottled liquid gunpowder meet requirements of continuous launching for at least 300 times.
For the pressure that the vessel has to maintain, here is a simple estimation:
Assuming that the weapon is designed with a firing rate of 600 rounds per minute (i.e., the rotational speed of the cylindrical cam is 600 rpm), the average time taken for each bullet launching is 100 milliseconds. As shown in
When the solenoid valve is opened, the gunpowder will flow from the pressure regulator into the injection aperture (30) of the plunger (7) through the valve opening and get into the combustion chamber (3) by the injection aperture (30). Assume that the constant pressure required for the pressure regulator to be maintained is Pr, the flow rate in the regulator could be considered to be approximately 0, and the pressure Pi at the outlet of the plunger nozzle is approximately equaled to atmospheric pressure, ignoring the effect of the liquid level difference. According to the Bernoulli equation, Pr=Pi+ρVi2/2, where ρ is the density of the liquid gunpowder, which assumed be approximately 1000 kg/m3. From the previous calculated value, Pr=Pi+0.183 MPa=0.284 MPa, it could be seen that in the ideal state Pr is less than three times of the atmospheric pressure, even taking into account the viscosity of the liquid and the friction of the hole, Pr should still be within the scope of implemented in practical production.
Since the projectiles are much smaller than the complete shelled bullet, therefore the magazine (31) of this inventive weapon has a greater capacity potential to implement on drum magazine and cylindrical magazine. Herein, the present invention is incorporated by reference with The Top Mounted Longitudinal Magazine (U.S. Pat. No. 4,905,394A), which has been published in the United States in 1990 and has been in use for more than 20 years. It's simple, lightweight and large capacity, especially suitable for this embodiment. This magazine is currently used by P90 which is produced by Belgium Fabrique Nationale Company, the magazine length is about 28 cm, 50 rounds capacity. The present embodiment uses 22 cm length magazine, its capacity could reach 60 rounds. As shown in
EFCU is the brain of the whole system, is one of the most core components of the system, and it is consisted of hardware and related software components, the diagram of hardware modules is shown in
As electronic components used by the present weapon, all electronic components and circuits in the entire embodiment need to meet the requirements of waterproof impact resistant and anti-electromagnetic.
The overall layout of the gun is shown in
The foregoing is intended only as a preferred embodiment of the present invention and is not intended to be limiting of the invention, and any modifications, equivalent substitutions, improvements, and the like, which are within the spirit and principles of the invention, must be within the scope of protection.
PTL1: U.S. Pat. No. 4,905,394A
NPL1:
Filing Document | Filing Date | Country | Kind |
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PCT/CA2017/051316 | 11/6/2017 | WO | 00 |