RU131142U1 - COMBINED ARROW AUTOMATIC ENGINE WITH BARREL AND BALANCING UNIT WITH ONE DRIVE PISTON - Google Patents

Abstract

Combined small arms automatic engine with recoil of the barrel and removal of powder gases using a balancing unit, including a barrel with a gas chamber and a muzzle brake, a shutter, a bolt frame with a rod and piston, a balancer with a rail, a return spring of a bolt frame with a shutter, a return spring balancer with a rack, the barrel spring, sprocket gears, characterized by the presence of a movable barrel in combination with an automatic engine with the removal of powder gases from the barrel channel with a balancing unit.

Description

- Field of technology:

The technical solution relates to automatic small arms and is aimed at improving the stability of weapons when firing bursts.

- Disclosure of utility model

Theoretical background

The results of studies on the formation of a recoil impulse of a hand-held automatic weapon with different automatic operation schemes, performed for the initial data of the AK74 assault rifle (Fig. 1), and the results of calculating the free recoil of a weapon (table) allow us to draw conclusions regarding the most rational nature of the recoil impulse transmission on the arrow.

Table The results of calculating the free rollback of weapons with different automation schemes Type of automation engine Moving weapons to the end of the roll, mm The removal of powder gases 86.48 Half-free shutter release 63.43 Balanced automation with two drive pistons 85.78

From the analysis of the results it follows that the automation circuitry with a half-free shutter recovers has the greatest advantage of the considered ones. The recoil momentum in a weapon of this type gradually increases over the entire automation cycle at a lower intensity compared to other engines in the main period of the shot, which ensures the transfer of a recoil momentum to the arrow, which favorably affects the stability of the weapon during firing. However, systems with this engine have a significant drawback - lower reliability of automation in comparison with systems with the removal of powder gases, which limits their application.

A similar nature of the change in the recoil momentum is with the barrel recoil system.

In weapons with the removal of powder gases, a momentum from the pressure of the powder gases on the front wall of the gas chamber is equal to the momentum of the moving parts, which significantly reduces the transmitted recoil momentum towards the end of the automation engine's operation, has a favorable effect on stability.

Systems with balanced automation, created as an alternative solution to systems with a classic layout, aimed at increasing the stability of weapons when firing bursts with the exception of strokes during automatic operation, have some advantages. As can be seen from the results of calculating the free rollback, the advantage of these systems over classical systems with the removal of powder gases is minimal, which is due to the transfer of the full pulse of the shot in a short period of time.

The traditional scheme of weapons using balanced automation is presented in figure 2.

The automation of such a scheme has two drive pistons, rigidly connected with the bolt frame 1 and the balancer 2. To synchronize the movement of the bolt frame and the balancer between them there is a kinematic connection through the sprockets 5.

Provided that the masses of the shutter frame with the shutter and the balancer are equal in this scheme, it is possible to completely exclude impacts of the moving parts in the extreme positions and to compensate for the reaction forces from the compressible return springs of the shutter frame with the shutter 3 and the balancer 4. The nature of the transfer of the recoil impulse of these systems with perfect balancing completely the nature of the recoil of non-automatic small arms.

The considered features of changing the recoil of a weapon in a rollback cycle determine the appropriate construction of a pulse diagram to improve its stability: the automation should provide a smooth change in the recoil momentum in the initial section (from the beginning to the end of the shot), similar to systems with a recoil of a half-free shutter or barrel, followed by with the exception of the transfer of the recoil momentum to the arrow on the remaining sections of the automation.

The necessary nature of the change in the recoil momentum makes it possible to obtain a circuit with a combined automation engine with recoil of the barrel using a balancing unit with one drive piston.

A schematic diagram of this type of automation of small arms is presented in figure 3. The automation engine consists of a barrel with a gas chamber and a muzzle brake 2, a bolt 3, a bolt frame with a rod and a piston 4, a balancer with a rack 5, a return spring for the bolt frame with a bolt 6, a return spring for the balancer 7, barrel spring 8, pinion gears 9 .All elements of the automation engine are located in a fixed box of weapons 1.

Automation engine operation description

The position before starting the engine is presented in figure 4. The barrel before the shot is at a distance x from the box of weapons, the bolt and bolt frame - at a distance of x ₁ from the box of weapons (roll length), at the same distance x ₁ relative to the box - a balancer with a rail. The barrel is closed by a bolt, locked by turning around its axis, like an AK74 assault rifle.

After the shot is fired, the moving parts (barrel, bolt, bolt frame, balancer) roll back under the action of the pressure force of the powder gases to the bottom of the barrel channel (force P _kn ), compressing the springs 6, 7, 8. Until the bullet passes through the vent hole, the force P _kn is moving, and the moving parts during this time gain speed V ₁ , moving a distance Δx relative to the initial position (figure 5).

After the bullet through the vent hole, the powder gases discharged from the barrel into the gas chamber act on the piston of the bolt frame and cause it to roll back intensively together with the balancer (the kinematic connection between the bolt frame and the balancer is via gear wheels). In this case, the pressure force of the powder gases on the front wall of the gas chamber (force F _to ) leads to inhibition of the barrel and the bolt rigidly connected to it. At this point, the barrel with the shutter travels the distance Δx ₂ relative to the initial position, and their speed drops to the value of V ₂ , and the shutter with the balancer moves to the distance Δx ₃ , which is the sum of the distance traveled with the barrel Δx ₂ and relative to its x _sp (Fig. .6).

During the aftereffect, a reaction from the operation of the muzzle brake (force F _t ) is added to the existing force factors, which also leads to the damping of the barrel rollback speed. In the aftereffect, the shutter is unlocked, which is rolled back together with the shutter frame and the balancer (Fig. 7).

Then the bolt frame rolls back together with the bolt and balancer to their extreme rear positions. The length of the barrel rollback is less than the length of the recoil of the bolt frame, and by the time the bolt frame and the balancer arrive in their extreme rear position, the barrel manages to return to its extreme front position under the action of its spring (Fig. 8).

Then, the shutter frame rolls along with the shutter and balancer under the influence of their return springs, while the barrel is already in its original position.

Calculation of the theoretical impulse diagram of a weapon when using this automation engine

To calculate the impulse diagram of the weapon, let us set the mass characteristics of the elements of the automation engine:

- the mass of the barrel with a gas chamber and a muzzle brake: M _C = 0.8 kg,

- mass of the bolt frame: M _sp = 0.2 kg,

- mass of the shutter: M _Z = 0.1 kg,

- mass balancer: M _B = 0.3 kg.

The calculation is made for the ammunition of 5.45 × 39. Barrel length L _trunk = 415 mm.

The parameters of the side gas engine are adopted corresponding to the AK74 submachine gun [1].

Until the bullet passes through the vent hole in this automatic engine, the recoil force is determined by the reaction from the compression of the barrel spring. Based on the calculation of the main task of internal ballistics, the pressure pulse of the powder gases at the bottom of the barrel channel by the time the bullet passes the vent

I _G = (q + λ ₁ · ω) · V _G = (3.42 + 0.42 · 1.4) 804.14 · 10 ^-3 = 3.22 N · s,

where q is the mass of the projectile;

λ ₁ is the first Piober coefficient;

ω is the mass of the charge;

V _G is the velocity of the projectile by the time the bullet passes through the vent hole.

The speed of the moving parts (barrel, bolt with shutter, balancer) at a given point in time without taking into account the resistance force of the spring is

,

,

The impulse from the pressure of the powder gases on the front wall of the gas chamber, equal in value and opposite in direction to the pulse acting on the piston of the shutter frame, for the side gas engine of the AK74 machine is estimated to be I _K = 3 N · s.

After the bullet leaves the barrel, the muzzle brake starts, the pulse-structural characteristic of which in the AK74 assault rifle is α _m = 0.42 [1], then

I _in = (q + α _m · β · ω) · V _d = (3.42 + 0.42 · 1.51 · 1.4) · 900 · 10 ^-3 = 3.9 N · s.

The end of operation of the automation engine approximately coincides with the end of the aftereffect. Thus, the recoil momentum when compressing the barrel spring at this point in time

I _St = I _in -I _to = 3.9-3.0 = 0.9 N · s.

at barrel speed by the end of the automation engine

.

.

Thus, by the end of the aftereffect, under the influence of pulses from the pressure force on the front wall of the gas chamber and the reaction from the operation of the muzzle brake, the barrel begins to move in the opposite direction, i.e. the barrel begins to roll.

The barrel manages to return to its extreme forward position before the recoil of the bolt frame and the balancer are completely rolled back, which is accompanied by a blow, as a result of which the impulse transmitted to the shooter during the barrel rollback cycle is restored

I _STKPP = I _article = 0> 9 N · s.

Provided that the mass of the balancer is equal to the mass of the bolt frame with the shutter of the recoil momentum during the movement of the bolt frame and the balancer will not be transferred to the arrow.

The approximate nature of the transmission of the recoil pulse to the arrow with this scheme of operation of the automation engine is shown in Fig.9.

Figure 9 shows that at the end of the recoil of the barrel an impulse of 0.9 N · s is transmitted, with a shot pulse of 3.9 N · s. In classical schemes with a fixed receiver, the full ammunition impulse is always transmitted to the arrow by the end of the recoil . Thus, the use of this scheme allows to reduce the recoil momentum by about 4 times compared with the classical schemes of weapon automation. In this case, the recoil momentum gradually increases over the entire time of the shot.

An analysis of the formation of the recoil impulse allows us to expect an increase in the stability of the weapon with the described automation engine and an increase in the combat effectiveness of the weapon.

- Brief description of the drawings:

Figure 1 is a comparison of pulse diagrams of weapons with various types of automation.

Figure 2 - schematic diagram of weapons with balanced automation with two drive pistons.

Figure 3 - schematic diagram of a combined engine automation.

Figure 4 - position of the elements of the automation engine before the start of the shot.

Figure 5 - the position of the elements of the automation engine before the flow of powder gases into the gas chamber.

6 - the position of the elements of the automation engine after the start of the flow of powder gases into the gas chamber.

7 - the position of the elements of the automation engine after the bullet takes off from the barrel.

Fig - the position of the elements of the automation engine at the end of the rollback of the bolt and the balancer.

Fig.9 is an exemplary nature of the transmission of the recoil pulse to the arrow during operation of the combined automation engine.

- Bibliographic list:

1. Galagan L.A., Chirkov D.V. Tilting moment compensators AK74. Intelligent systems in production No. 1, 2012

Claims (1)

Combined small arms automatic engine with recoil of the barrel and removal of powder gases using a balancing unit, including a barrel with a gas chamber and a muzzle brake, a bolt, a bolt carrier with a rod and piston, a balancer with a rail, a bolt return spring with a bolt, a return spring balancer with rack, barrel spring, sprocket gears, characterized by the presence of a movable barrel in combination with an automation engine with the removal of powder gases from the barrel channel with a balancing unit.

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