A METHOD TO ACHIEVE THE CASELESS AMMUNITION FIRING WITH LIQUID PROPELLANT FOR AUTOMATIC WEAPONS

Abstract

The present invention proposed a method to achieve the caseless ammunition firing with liquid propellant for automatic weapons. The weapons with this method were driven by a servo motor that led a slider (9) for linear reciprocating motion, and then the slider (9) drove a combustion chamber (3) and a rotary lock (4) to complete the projectile loading and the combustion chamber (3) locking. The combustion chamber (3) locking was done with the help of a fixed plunger (7).

A separated binary liquid gunpowder was used as a propellant. The constant liquid propellant injection pressure was maintained by a constant pressure regulator; and an electronic fire control unit (EFCU) precisely control two solenoid valves opening time in order to control the injection amount of the mixture. The gunpowder was injected through the nozzle on the plunger (7), and was ignited by an electronic igniter to launch the projectile.

Claims

1. A method to achieve automatically reciprocating motion and latching the bolt with electric means for firearms, characterized in that the method comprises: the projectile filling and bolt latching were achieved after reciprocating motion driven by electric motor; the driven force can be from a rotating servo motor or a linear servo motor; the bolt was driven by motor to perform the reciprocating motion which leads the projectile filling and bolt locking; the position of the bolt can be obtained from the signal of the servo motor, which could also determine whether the bolt has been locked; in the locked state, the trigger signal could trigger gunpowder injection and ignition as well as a series of follow-up actions.

2. A method of automatically loading a projectile by linear reciprocating motion of the combustion chamber, characterized in that the method comprises: The combustion chamber, as a moving part inside the cartridge receiver, performed linear reciprocating motion along the axis of the bore, the front part of the combustion chamber is in a form of convex cone, the bore was shaped in a corresponding female cone; the cone-shaped end of the combustion chamber has a triangular fin, the bore has a corresponding groove for the fin, the groove can provide the guidance for the projectile to enter the bore, here known as the projectile guidance groove; the magazine was slightly tilted into the range of the female cone of the bore alone the axis of the feed lips; the projectile was pushed against the outer wall of the combustion chamber under the force of the magazine spring; and the projectile was sliding on the outer wall of the combustion chamber with frictions; when the combustion chamber left the bore with a rearward motion, the cone-shaped end moved back and positioned completely rear of the magazine opening, a projectile will be pushed by spring into the space where the combustion chamber doing reciprocating motion, when the combustion chamber moved in the direction to the bore, the triangular fin on the cone-shaped end will push the projectile out of the feed lips of the magazine, the projectile will be pushed along the projectile guidance groove into the female cone section of the bore, when the projectile just entered the bore, the feed lips still held the projectile partially, through the self-guided ability of the female cone, the projectile will enter automatically into the bore under the pushing force of the cone-shaped end to complete the loading.

3. A method of achieving the gastight locking of bore and combustion chamber, characterized in that the method comprises: The main body of the combustion chamber has a thick-walled tubular shape, the gastight sealing of the combustion chamber and the bore is achieved by their conical surfaces touching; the combustion chamber body and its cone-shaped end are made with different materials. The main body of the combustion chamber is made of high strength material; the cone-shaped end 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 and the combustion chamber; there is a gear-shaped rotary lock at the tail of the combustion chamber, inside the cartridge receiver, there are the corresponding teeth; the rotary lock and combustion chamber are coaxial, rotary lock is positioned outside of the combustion chamber's tail, the rotary lock can rotate around the axis freely, the tail of the combustion chamber is a shaft shoulder, together with a retaining ring, they can limit the rotary lock sliding axially; the cartridge receiver has a L-shaped guide groove, the rotary lock can be moved along the guide groove with the guidance of guide pin; when the projectile loading is completed, the combustion chamber cone-shaped end and bore's female cone overlap to stop the movement, and the rotary lock will continue to rotate under the combined effect the guide pin and guide groove, and finally make the gear teeth of the rotary lock overlap with corresponding teeth inside the cartridge receiver, then the combustion chamber can no longer move back and forth along the axial to achieve latch-up; rotary lock teeth and the cartridge receiver teeth are shaped in wedge, by rotating of the rotary lock, combustion chamber can be pushed as close as possible to the bore, so that the cone-shaped end and the female cone of the bore can fit closely.

4. A method of achieving the gas tightness at the front end of a combustion chamber by means of a cone-shaped end of the projectile extending into a combustion chamber, characterized in that the method comprises: The diameter of the gas outlet of the combustion chamber is smaller than the diameter of the projectile, but slightly larger than the diameter of the trailing end of the projectile. The gas outlet is in form of a certain trumpet shape outward. During the loading of the projectile, the front tip of the projectile will enter into the bore under the pushing force from combustion chamber, at the same time the end of the projectile will be partially entered the combustion chamber through the gas outlet to form the gastight condition.

5. A method of achieving gas tightness of the combustion chamber by a fixed plunger, characterized in that the method comprises: A cylindrical plunger and combustion chamber are coaxial, the plunger was fixed on the cartridge receiver with the screw, the plunger is inserted into the combustion chamber through the tail end, with a clearance fit to form certain gastight conditions, similar to the piston and cylinder; The combustion chamber is guided by the guidance groove and the plunger to maintain accuracy of reciprocating motion along a straight line; after the burning of the gunpowder, the combustion chamber gas outlet transferred energy to the projectile while the plunger is also taken the gas pressure and passes it to the cartridge receiver.

6. A method of performing gunpowder injection and ignition by means of a stationary plunger, characterized in that the method comprises: The plunger has machined deep holes along the axial direction, the holes are used to install the igniter and as a fuel injection aperture.

7. A method for performing joint-action of liquid gunpowder injection and ignition with respect to the characteristics of liquid gunpowder leaking, which is characterized in that the method comprises: The retention of liquid gunpowder in the combustion chamber always occurs at a moment after the trigger is pulled; the injection and ignition of the liquid gunpowder are carried out in conjunction, the injection of the fuel and the oxidizer is before the ignition; when signal sent by the trigger, EFCU will determine the other launch conditions and then issued the turn-on signal to solenoid valve to inject fuel and oxidizer, at the moment when solenoid valve closed, EFCU will send the ignition command to igniter to complete the ignition; the total time consumption of injection and ignition was controlled within the response time of human in order to avoid shooting delay.

8. A method of performing accurate single shot, characterized in that the method comprises: In the single shot mode, after each launch, the gun will give an appropriate delay before performing latching and stop, and waiting until the next ignition command; when the trigger is pulled again, EFCU will give conjunction signal to inject gunpowder and complete the ignition launch, after the ignition, EFCU will perform the delay again and then drive the bolt to complete the loading and locking, the delay can ensure the subsequent action performing after that the previous projectile has left the muzzle.

9. A method of achieving high-speed firing, characterized in that the method comprises: In the burst and full auto mode, the combustion chamber will continuously perform the reciprocating cycle to complete the loading and locking without cease until pre-set number of shots was achieved or the trigger was released; EFCU can determine the combustion chamber position from the angular displacement signal of the servo motor, and within the appropriate time period, give command of gunpowder injection and ignition according to the combustion chamber position information; In each of the high-speed continuous chamber-lock cycles, there is a moment that the combustion chamber is at rest in a locking state, the gunpowder and ignition are completed during this time period, the servo motor and other moving parts are always in a continuous cycle of running state in order to avoid the frequent turn on and turn off which could cause delay and affect the shooting speed.

10. A method of implementing fire controlling by using microcontroller, characterized in that the method comprises: Using microcontroller and relative program to actualize intelligent fire controlling unit, all kinds of electronic switches such as: trigger, fire mode switch, power selection switch and environment-related sensors are considered as input devices. Solenoid valves, igniter, gunpowder and projectiles remaining quantity indicator are used as output devices. and the servo motor controller has both input and output functions. The EFCU processes the input command according to the pre-set program and outputs the result to the corresponding output device.

11. A method of implementing a trigger function by using an electronic switch via EFCU, characterized in that the method comprises: The use of an electronic switch to achieve the trigger function, the switch provides trigger signal for EFCU, and then the subsequent command of the EFCU will instruct the other components to complete the shooting action.

12. A method of implementing safety and fire mode switching via EFCU by using an electronic switch, characterized in that the method comprises: The use of rotary band switch or other forms of multi-pole switch to achieve the weapon's fire mode switching function, different rotation position on behalf of the safety off (power off), single shot, multiple shot (2 shots or 3 shots) and burst fire mode; when the trigger signal is sent, the EFCU will determine the fire mode according to the state of the firepower mode switch.

13. An method of implementing the weapon launching power adjusting by means of an electronic switch via EFCU, characterized in that the method comprises: The use of rotary band switch or other forms of multi-pole switch to achieve the selection of weapon launching power, the corresponding launching power can be high, medium and low and anti-riot non-lethal power; EFCU will determine the opening duration of the solenoid valve according to the position of the switch, and control the amount of gunpowder injected to determine the launch power.

14. An method of implementing the gun grenades launching and blank launching by means of an electronic switch via EFCU, characterized in that the method comprises: Using electronic switch to achieve the grenade (blank) launching. When the grenade mode ( ) is turned on, the combustion chamber will always be in the locked state, the system will no longer load the projectile until the switch is turned off.

15. A method of adjusting an internal trajectory to automatically adapt the variance of ambience, characterized in that the method comprises: Through the temperature, humidity and pressure sensor to obtain environmental shooting parameters, EFCU determines the corresponding correction parameters, adjust the solenoid valve opening duration to change the amount of gunpowder injection, by adjusting the internal trajectory characteristics to ensure the consistency of the external trajectories.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0021] FIG. 1 The main mechanical parts.

[0022] FIG. 2 The main moving parts.

[0023] FIG. 3 The projectile loading process.

[0024] FIG. 4 The bore, combustion chamber and the projectile loading action.

[0025] FIG. 5 The rotary lock and cartridge receiver.

[0026] FIG. 6 The path cylindrical cam.

[0027] FIG. 7 The cam and camshaft timing scheme.

[0028] FIG. 8 The structure of the plunger.

[0029] FIG. 9 The seat of solenoid valve.

[0030] FIG. 10 The magazine and feed lips.

[0031] FIG. 11 The magazine layout and mounting.

[0032] FIG. 12 The EFCU module diagram.

[0033] FIG. 13 The flow chart of EFCU software boot process.

[0034] FIG. 14 The flow chart of EFCU operation.

[0035] FIG. 15 The flow chart of EFCU shutdown process.

[0036] FIG. 16 The overall layout of the gun.

[0037] FIG. 17 The weapon system diagram.

DESCRIPTION OF EMBODIMENTS

[0038] 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.

[0039] The main embodiment process of the method provided by the invention comprises the following steps:

[0040] 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.

[0041] The main mechanical parts of the rifle as shown in FIG. 1, mainly contains the following components: barrel (1), sleeve of cartridge receiver (2), combustion chamber (3), rotary lock (4), guide pin (5), retaining ring (6), plunger (7), valve seat (8), slider (9), rail bracket (10), cylindrical cam (11), camshaft (12), positioning pin (13). And EFCU, servo motor, solenoid valve, pressure regulator, all kinds of switches, sensors, indicator lights and batteries are not shown with figures.

[0042] 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, FIG. 1 shows the gross weight of all these parts is about 2.66 kg.

[0043] 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 FIG. 2.

[0044] 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 FIG. 3.

[0045] 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 FIG. 4.

[0046] 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.

[0047] 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 FIG. 5.

[0048] 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 FIG. 6.

[0049] It could be seen from FIG. 6 that the path surrounds the cylindrical cam (11). The cam path is a horizontal arc perpendicular to the camshaft (12) from the A-B segment. When the cam pin of the slider traveled from point A to point B, the rotated angle of the cylindrical cam is about 90 degrees, during which the cam pin (24) of the slider (9) will be in a relatively stationary state while the combustion chamber (3) is also in a latching state. In the high-speed full auto mode, the cam will rotate continuously without interruption. Whenever the cam pin (24) of the slider (9) is in between point A and point B, the EFCU determines the cam position by the angular displacement of the servo motor, and completes the gunpowder injection and ignition during this period.

[0050] The height of the cam path curve H.sub.c 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 L.sub.o, the diameter (or width) of the magazine's feed lips (18) D.sub.m and the length of the 30 degrees locking angle arc L.sub.a that is travelled by the guide pin (5) along the sleeve of cartridge receiver (2) when the combustion chamber (3) is locked. Therefore, H.sub.c=L.sub.o+D.sub.m+L.sub.a, (note that the helix angle of the helical groove is limited to 45 degrees).

[0051] 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 D.sub.c=8H.sub.c/3

[0052] The distance travelled by the combustion chamber (3) L.sub.c is: L.sub.c=L.sub.o+D.sub.m

[0053] 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 FIG. 7, the present embodiment uses a semi-circular (40) camshaft (12) to connect the servo motor and the cylindrical cam (11), which completely eliminates the timing problems caused by the assembly.

[0054] 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 FIG. 8, the structure of the ignition device on the plunger could refer to the manufacturing process of the car spark plug, considering that the maximum chamber pressure could reach to 430 MPa, therefore the plunger (7) needs to be made of high strength steel and high strength insulating ceramic.

[0055] 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 FIG. 9, there are 2 cylindrical solenoid valve sockets (29) on the tail end of the valve seat (8), which can facilitate the plugging of the solenoid valve.

[0056] 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.

[0057] In the present embodiment, the liquid propellant is mixed until it enters the combustion chamber, thereby ensuring the safety of such weapons.

[0058] 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.

[0059] For the pressure that the vessel has to maintain, here is a simple estimation:

[0060] 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 FIG. 6, in the fully automatic mode, the slider cam pin (24) travelled from point A to point B, the cam rotation angle is about 90 degrees, during which EFCU will complete the gunpowder injection and ignition process, the ignition time is negligible, then the time taken for slider cam pin travelling from A to B is about T.sub.i=10090/360=25 ms. The amount of liquid gunpowder injected each time is C.sub.i=1.5 ml, its flow rate Q.sub.i=1.5/0.025=60 ml/sec, the injection nozzle diameter D.sub.i=2 mm, and the gunpowder injection rate is V.sub.i=4C.sub.i/T.sub.iD.sub.i.sup.2, then the rate can be calculated as V.sub.i=19.1 m/s.

[0061] 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 P.sub.r, the flow rate in the regulator could be considered to be approximately 0, and the pressure P.sub.i 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, P.sub.r=P.sub.i+V.sub.i.sup.2/2, where is the density of the liquid gunpowder, which assumed be approximately 1000 kg/m3. From the previous calculated value, P.sub.r=P.sub.i+0.183 MPa=0.284 MPa, it could be seen that in the ideal state P.sub.r is less than three times of the atmospheric pressure, even taking into account the viscosity of the liquid and the friction of the hole, P.sub.r should still be within the scope of implemented in practical production.

[0062] 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 FIG. 10, in this embodiment, the magazine is loaded above the sleeve of cartridge receiver (2), the feed lips (18) a slightly downwardly inclined angle (41) to facilitate the projectile to enter into the bore. In addition, in the present embodiment, the magazine loading is different with P90, where the magazine is arranged at the rear of the firearm body, so that the arrangement of the hand and the guide rail will not be affected, as shown in FIG. 11.

[0063] 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 FIG. 12, the flow chart of software boot process is shown in FIG. 13, the flow chart of EFCU operation is shown in FIG. 14, and FIG. 15 shows the EFCU shutdown flow chart. In the case with installation of environmental sensors, the EFCU will detect the firing parameters each time the trigger triggers, and the EFCU will obtain the actual parameters from the individual environmental sensor and determine the correction value for valve opening time by the interpolation algorithm.

[0064] 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.

[0065] The overall layout of the gun is shown in FIG. 16, using a 20 inch heavy barrel (1), aluminum alloy hand guard and rail (32), engineering plastic buttstock (33) and grip (34), the overall length of the gun does not exceed 790 mm, the height is less than 220 mm, the total weight is within 3.5 kg (including battery (35), but without magazine and liquid gunpowder tank (36). Wherein the fuel and the oxidizer tank may be made of aluminum alloy or other pressure resistant and corrosion resistant materials, and the inside thereof is filled with fuel and oxidizer respectively. The tank itself could be mounted and fixed by means of the rails on the lower part of the hand guard, with the outlet of the fuel and oxidizer connected to the quick plug valve on the gun.

[0066] 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.

EXAMPLES

Industrial Applicability

Reference Signs List

Reference to Deposited Biological Material

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Citation List

Patent Literature

[0067] PTL1: U.S. Pat. No. 4,905,394A

Non Patent Literature

[0068] NPL1: