A self-driven, adjustable tail nozzle mechanism for recoilless rifles

Abstract

The application discloses a self-driving regulation tail jet mechanism for a non-seating force gun, comprising a launching barrel, a tail jet pipe, a reset spring, a dynamic throttle film group, a driving disc, an execution piston and a sealing ring. The self-driving regulation tail jet mechanism is connected to the non-seating force gun in a nested structure, the driving disc drives the dynamic throttle film group to adjust the opening degree of the tail jet pipe through the execution piston based on the reset spring, and the sealing ring is installed on the inner and outer sides of the execution piston to match the recoil force generated in the process of regulating the projectile launching. The powder gas generated by the projectile launching drives the reciprocating linkage of the regulation tail jet mechanism to realize the opening and closing of the dynamic throttle film group, and the self-driving matching linkage, the propulsion energy efficiency improvement, the significant recoil reduction and the good projectile adaptability are achieved in the application of the non-seating force gun.

Description

Technical Field

[0001] This invention relates to the field of recoilless gun nozzle technology, specifically, to a self-driven adjustable nozzle mechanism for recoilless guns. Background Technology

[0002] As a core dynamic balancing component of recoilless rifles, the nozzle's design directly affects the weapon system's recoil cancellation efficiency, exhaust gas stability, and overall firing performance. Recoilless rifles employ an open-bolt design with an open breech end and an open nozzle, resulting in some energy loss. The energy of some high-temperature, high-pressure, high-speed airflow cannot be fully converted into propulsion, limiting the projectile's initial velocity and other performance characteristics. Based on these shortcomings, existing designs have proposed solutions such as breech-locked and handle-locked structures, but these cannot dynamically adjust the exhaust jet range according to projectile movement and firing progress, thus limiting the weapon's service life and firing performance. These issues have become one of the key factors restricting the improvement of recoilless rifle combat effectiveness. Summary of the Invention

[0003] To address the problems of the existing technology, this invention proposes a self-driven adjustable tail nozzle mechanism for recoilless rifles. The mechanism is connected to the recoilless rifle in a nested structure. Based on a return spring, an actuator piston drives a drive disc to adjust the tail nozzle opening in conjunction with a dynamic throttling diaphragm assembly. Sealing rings are installed on the inner and outer sides of the actuator piston to match and control the recoil force generated during projectile launch. This invention aims to solve problems such as low energy conversion efficiency, poor projectile launch performance, limited barrel life, and insufficient dynamic control capability in existing tail nozzle structures.

[0004] To achieve the objectives of this invention, the following technical solution is adopted:

[0005] A self-driven adjustable tail nozzle mechanism for a recoilless rifle includes a launch tube, a tail nozzle, a return spring, a dynamic throttling diaphragm assembly, a drive disc, an actuator piston, a sealing ring, and a projectile body.

[0006] The front section of the launch tube is the barrel, the inner side of which is the breech. A nozzle connection groove is located at the rear end, which mates with the nozzle connection boss of the tail nozzle. A self-driven control chamber is located near the rear end of the launch tube, containing two annular cavities. The first stage is a piston movement chamber, housing the actuating piston. The actuating piston has inner and outer sealing grooves on its rear end face, each fitted with a sealing ring. The inner cavity of the actuating piston is a diaphragm movement platform, with multiple diaphragm guide grooves arranged circumferentially. The second stage is a spring movement chamber, housing a return spring. Between the two cavities are sequentially located a drive disc mounting groove (slightly smaller in diameter than the return spring) and a dynamic throttling diaphragm assembly mounting groove. The drive disc is installed in the drive disc mounting groove, and the dynamic throttling diaphragm assembly is installed in the dynamic throttling diaphragm assembly mounting groove. The piston movement chamber is connected to the breech through multiple guide holes. The projectile is installed inside the breech for firing.

[0007] The dynamic throttling diaphragm assembly consists of a circumferential array of multiple fan-shaped diaphragms nested together by lateral connecting bosses and lateral connecting grooves. A diaphragm groove is provided at the front end of each diaphragm, which engages with a guide boss on the drive disc. A diaphragm slide is provided at the rear end of each diaphragm, engaging with a diaphragm guide groove on the diaphragm motion platform to achieve diaphragm rotation. A helical slide arranged circumferentially on the drive disc engages with a helical groove on the actuator piston, enabling the drive disc to rotate and transferring the load to the diaphragm, thus achieving dynamic throttling diaphragm assembly linkage.

[0008] Furthermore, the self-driven control cavity is divided into two connected sections: the front section is the piston movement cavity, and the rear section is the spring movement cavity. The piston movement cavity has a transition section at the front that serves as a guide hole. The spring movement cavity is tubular inside and acts as a diaphragm movement platform. Multiple diaphragm guide grooves are arranged in a circular array on the front end face of the diaphragm movement platform, which are connected to the diaphragm slide on the diaphragm through the diaphragm guide grooves.

[0009] Furthermore, the actuator piston is in the form of a two-stage cylindrical tube, with the inner diameter of the front stage being smaller than that of the rear stage. The front stage has inner and outer sealing grooves of the same size, and two outer sealing grooves are provided on the outer side, with sealing rings installed. The rear stage has a circumferential array of spiral sliding grooves that penetrate both the inner and outer sides, which cooperate with the spiral sliding table arranged circumferentially on the drive disc to convert the axial movement of the actuator piston into the radial movement of the dynamic throttling diaphragm.

[0010] Furthermore, during the initial ignition stage of launch, the projectile is subjected to the pressure of the gas in the barrel and moves forward along the launch tube axis. The actuating piston overcomes a certain return spring force and moves forward along the launch tube axis. It drives the drive disk to rotate through the spiral slide, so that the dynamic throttling diaphragm group is linked to regulate a certain opening. As the actuating piston continues to move, the dynamic throttling diaphragm group also increases its opening.

[0011] Furthermore, during the post-muzzle effect phase, the gas pressure inside the gun barrel rapidly decreases, and the force exerted by the gas on the actuator piston is less than the force of the return spring, causing the actuator piston to move in the opposite direction along the axis. This causes the drive disc to rotate in the opposite direction via the spiral groove, which in turn causes the dynamic throttling diaphragm to reduce its opening. As the actuator piston returns to its initial position under the action of the return spring, the dynamic throttling diaphragm also returns to the closed state.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0013] 1. The self-driven regulating tail nozzle mechanism provided by the present invention is connected to the recoilless gun in a nested structure. It uses the gunpowder gas generated by the projectile to drive the reciprocating linkage of the regulating tail nozzle mechanism to realize the opening and closing of the dynamic throttling diaphragm group, thereby reducing the recoil generated by the projectile. It has four functions and advantages: self-driven matching linkage, improved propulsion energy efficiency, significant recoil reduction, and good projectile compatibility.

[0014] 2. Self-driven matching linkage. The self-driven control mechanism proposed in this invention is driven by the propellant gas to actuate the piston axially. By cooperating with the slot of the drive disk, the load is transferred to the diaphragm to achieve dynamic throttling diaphragm linkage, which has a dynamic control mechanism adapted to the internal flow field of the projectile.

[0015] 3. Improved Energy Efficiency. The dynamic throttling diaphragm module proposed in this invention can adjust the tail nozzle opening in real time according to the gas pressure throughout the entire launch cycle, thereby achieving full conversion of gas energy and improving propulsion efficiency.

[0016] 4. Significantly reduced recoil. The dynamic throttling diaphragm proposed in this invention can balance the recoil force generated by the initial gas impact of the projectile by adjusting the opening degree. It can achieve adaptive control of the gas pressure in the chamber throughout the firing cycle, breaking through the contradiction between recoil control and pressure stability in traditional recoilless rifles.

[0017] 5. Good ammunition compatibility. The self-driven control mechanism proposed in this invention can adaptively match projectiles with different propellant charges, enabling the recoilless rifle to adapt to the self-driven matching and control of the tail jet when firing various projectiles. Attached Figure Description

[0018] Figure 1 This is a three-dimensional exploded view of the overall structure of the present invention.

[0019] Figure 2 This is a two-dimensional cross-sectional view of the overall structure of the present invention.

[0020] Figure 3 This is a two-dimensional cross-sectional view of the launching tube and a diagram of the removed section of the present invention.

[0021] Figure 4 This is a three-dimensional structure and a two-dimensional planar schematic diagram of the dynamic throttling membrane module and membrane sheet of the present invention.

[0022] Figure 5 This is a three-dimensional structural diagram of the drive disk of the present invention.

[0023] Figure 6 This is a three-dimensional structural diagram of the piston used in this invention. Detailed Implementation

[0024] To make the technical solutions, structural features and functional principles of the present invention easier to understand, the present invention will be further described below with reference to the accompanying drawings and specific embodiments. The described embodiments are only some embodiments of the present invention.

[0025] In the description of this invention, it should be noted that certain terms indicating orientation or positional relationships are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this invention.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected" should be interpreted broadly. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0027] This invention discloses a self-driven adjustable tail nozzle mechanism for a recoilless rifle, comprising a launch tube, a tail nozzle, a return spring, a dynamic throttling diaphragm assembly, a drive disc, an actuator piston, a sealing ring, and a projectile. The launch tube and tail nozzle are connected by a threaded connection to form the main structure of the recoilless rifle. A self-driven adjustment chamber is provided at the rear end of the launch tube. The self-driven adjustment mechanism, consisting of the return spring, the dynamic throttling diaphragm assembly, the drive disc, the actuator piston, and the sealing ring, is located within this chamber. The dynamic throttling diaphragm assembly, composed of multiple diaphragms, adjusts the opening of the launch tube's tail nozzle channel by cooperating with the drive disc and the actuator piston. The return spring, located within the self-driven adjustment chamber of the launch tube, is connected to the actuator piston and achieves self-driven reciprocating motion using the high-temperature, high-pressure gas generated by the projectile's launch.

[0028] The launch tube is a cylindrical structure with a barrel at the front and a bore inside. A nozzle connection groove is provided at the rear end, which mates with a nozzle connection boss on the tail nozzle. A self-driven control chamber is provided near the rear end of the launch tube. The chamber has two annular cavities: a piston movement chamber in the front, which houses the actuator piston, and a spring movement chamber in the rear, which houses the return spring. Between the two cavities are a drive disc mounting groove and a dynamic throttling diaphragm assembly mounting groove, both with a diameter slightly smaller than that of the return spring. The drive disc is installed in the drive disc mounting groove, and the dynamic throttling diaphragm assembly is installed in the dynamic throttling diaphragm assembly mounting groove. The piston movement chamber is connected to the bore through multiple guide holes, and the projectile is installed inside the bore for firing.

[0029] The dynamic throttling diaphragm assembly consists of a circumferential array of multiple fan-shaped diaphragms nested together by lateral connecting bosses and lateral connecting grooves. A diaphragm groove is provided at the front end of each diaphragm, which engages with a guide boss on the drive disc. A diaphragm slide is provided at the rear end of each diaphragm, engaging with a diaphragm guide groove on the diaphragm motion platform to achieve diaphragm rotation. A helical slide arranged circumferentially on the drive disc engages with a helical groove on the actuator piston, enabling the drive disc to rotate and transferring the load to the diaphragm, thus achieving dynamic throttling diaphragm assembly linkage.

[0030] The self-driven control cavity is divided into two sections connected together. The inner cavity of the front section is the piston movement cavity, and the inner cavity of the rear section is the spring movement cavity. The front part of the piston movement cavity has a transition section as a guide hole. The inside of the spring movement cavity is cylindrical and serves as a diaphragm movement platform. Multiple diaphragm guide grooves are arranged in a circular array on the front end face of the diaphragm movement platform. The diaphragm guide grooves are connected to the diaphragm slide on the diaphragm.

[0031] The drive disk is annular, with multiple cylindrical guide protrusions arranged circumferentially on the rear, which are connected to the diaphragm slide groove of the dynamic throttling diaphragm module, and multiple outwardly extending cylindrical spiral slides are arranged circumferentially.

[0032] The actuator piston is a two-stage cylindrical tube. The inner diameter of the front stage is smaller than that of the rear stage. The front stage has inner and outer sealing grooves of the same size, and two outer sealing grooves are provided on the outer side, and a sealing ring is installed. The rear stage has a circumferential array of spiral sliding grooves that penetrate through the inner and outer sides. These grooves cooperate with the spiral sliding table arranged circumferentially on the drive disc to convert the axial movement of the actuator piston into the radial movement of the dynamic throttling diaphragm.

[0033] The reset spring is placed inside the spring movement cavity of the launching tube and connected to the actuating piston to achieve its reciprocating motion. The sealing rings are respectively installed in the inner sealing groove and the outer sealing groove of the actuating piston to prevent high-temperature and high-pressure gas from leaking into the spring movement cavity and causing it to malfunction.

[0034] The present invention will be further described below through embodiments and in conjunction with the accompanying drawings.

[0035] In the diagram: 1—launch tube; 101—barrel; 102—bore; 103—guide hole; 104—piston movement cavity; 105—spring movement cavity; 106—drive disc mounting slot; 107—dynamic throttling diaphragm assembly mounting slot; 108—self-driven control section; 109—nozzle connection slot; 110—diaphragm movement platform; 111—diaphragm guide slot; 2—tail nozzle; 201—nozzle connection boss; 20 2—Nozzle expansion section; 3—Reset spring; 4—Dynamic throttling diaphragm assembly; 401—Diaphragm; 402—Diaphragm slide; 403—Diaphragm groove; 404—Side connecting boss; 405—Side connecting groove; 5—Drive disc; 501—Guide boss; 502—Helical slide; 6—Actuating piston; 601—Helical groove; 602—Inner sealing groove; 603—Outer sealing groove; 7—Sealing ring; 8—Projectile body.

[0036] This embodiment provides a self-driven, adjustable tail nozzle mechanism for recoilless rifles. Figure 1 , Figure 2 These are, respectively, the three-dimensional exploded view and the two-dimensional cross-sectional view of the overall structure provided in the embodiments of the present invention, as follows: Figure 1 , Figure 2 As shown, the self-driven tail nozzle control mechanism is connected to the recoilless rifle in a nested structure, including a launch tube 1, a tail nozzle 2, a return spring 3, a dynamic throttling diaphragm assembly 4, a drive disc 5, an actuator piston 6, a sealing ring 7, and a projectile 8. The launch tube 1 and the tail nozzle 2 are connected by a threaded connection to form the main structure of the recoilless rifle. A self-driven control section 108 is provided at the rear end of the launch tube 1. The self-driven control mechanism, composed of the return spring 3, the dynamic throttling diaphragm assembly 4, the drive disc 5, the actuator piston 6, and the sealing ring 7, is placed in the self-driven control section 108. The dynamic throttling diaphragm assembly 4 is composed of multiple diaphragms 401 that cooperate with each other. It adjusts the opening of the tail nozzle channel of the launch tube 1 by cooperating with the drive disc 5 and the actuator piston 6. The return spring 3 is placed in the self-driven control section 108 of the launch tube 1 and connected to the actuator piston 6. It achieves self-driven reciprocating motion with the help of the high-temperature and high-pressure gas generated by the projectile 8.

[0037] Figure 3 This is a two-dimensional cross-sectional view of the launching tube and a view of the removed section of the present invention, combined with... Figure 3As shown, the front section of the launch tube 1 is a barrel 101, the inner side of which is a barrel 102. A nozzle connecting groove 109 is provided at the rear end, which mates with the nozzle connecting boss 201 of the tail nozzle 2. A self-driven control chamber 108 is provided near the rear end face of the launch tube 1, containing two annular cavities. The first stage is a piston movement chamber 104, which houses the actuating piston 6. The actuating piston 6 has an inner sealing groove 602 and an outer sealing groove 603 on its inner and outer walls near its rear end face, both fitted with sealing rings 7. The inner cavity of the actuating piston 6 is a diaphragm movement platform 110. The diaphragm motion platform 110 is provided with multiple diaphragm guide grooves 111 arranged in a circumferential ring; the next stage is a spring motion cavity 105, which is equipped with a return spring 3; between the two cavities, there are sequentially arranged drive disk mounting grooves 106 and dynamic throttling diaphragm assembly mounting grooves 107 with a diameter slightly smaller than that of the return spring 3. The drive disk 5 is installed in the drive disk mounting groove 106, and the dynamic throttling diaphragm assembly 4 is installed in the dynamic throttling diaphragm assembly mounting groove 107; the piston motion cavity 104 is connected to the gun barrel 102 through multiple guide holes 103; the projectile 8 is installed in the gun barrel 102 for firing.

[0038] Figure 4 This is a three-dimensional structure and a two-dimensional planar schematic diagram of the dynamic throttling membrane module and diaphragm of the present invention, combined with... Figure 4 As shown, the dynamic throttling diaphragm assembly 4 is composed of a circumferential array of multiple fan-shaped diaphragms 401, which are nested and fitted together by side connecting bosses 404 and side connecting grooves 405. The front end of the diaphragm 401 is provided with a diaphragm groove 403, which is connected to the guide boss 501 on the drive disk 5. The rear end of the diaphragm 401 is provided with a diaphragm slide 402, which is fitted with the diaphragm guide groove 111 on the diaphragm motion platform 110 to realize the rotational movement of the diaphragm 401. The spiral slide 502 arranged circumferentially on the drive disk 5 is connected to the spiral slide groove 601 of the actuator piston 6 to realize the rotational movement of the drive disk 5 and transmit the load to the diaphragm 401 to achieve the linkage of the dynamic throttling diaphragm assembly 4.

[0039] Combination Figure 3 , Figure 4 As shown, the self-driven control cavity 108 is divided into two sections connected together. The inner cavity of the front section is the piston movement cavity 104, and the inner cavity of the rear section is the spring movement cavity 105. The front part of the piston movement cavity 104 has a transition section as a guide hole 103. The inside of the spring movement cavity 105 is in the shape of a circular tube, serving as a diaphragm movement platform 110. Multiple diaphragm guide grooves 111 are arranged in a circular array on the front end face of the diaphragm movement platform 110. The diaphragm guide grooves 111 are connected to the diaphragm slide 402 on the diaphragm 401 through the diaphragm guide grooves 111.

[0040] Figure 5 This is a three-dimensional structural diagram of the drive disk of the present invention, combined with... Figure 4 , Figure 5As shown, the drive disk 5 is annular, with multiple cylindrical guide protrusions 501 arranged circumferentially on the rear side, which are connected to the diaphragm groove 403 of the dynamic throttling diaphragm assembly 4, and multiple outwardly extending cylindrical spiral slides 502 arranged circumferentially.

[0041] Figure 6 This is a three-dimensional structural diagram of the piston used in this invention, combined with... Figure 4 , Figure 5 , Figure 6 As shown, the actuator piston 6 is a two-stage cylindrical tube. The inner diameter of the front stage is smaller than that of the rear stage. The front stage has an inner sealing groove 602 and an outer sealing groove 603 of the same size inside and outside. Two outer sealing grooves 603 are provided on the outer side, and a sealing ring 7 is installed. The rear stage has a circumferential array of spiral sliding grooves 601 that penetrate inside and outside. These grooves cooperate with the spiral sliding table 502 arranged circumferentially on the drive disk 5 to convert the axial movement of the actuator piston 6 into the radial movement of the diaphragm 401 of the dynamic throttling diaphragm group 4.

[0042] The reset spring 3 is placed inside the spring movement cavity 105 of the launching tube 1 and connected to the actuating piston 6 to achieve its reciprocating motion. The sealing rings 7 are respectively installed in the inner sealing groove 602 and the outer sealing groove 603 of the actuating piston 6 to prevent high-temperature and high-pressure gas from leaking into the spring movement cavity 105 and causing it to malfunction.

[0043] The functional principle and specific technical effects of the self-driven regulating tail spray mechanism provided in the embodiments of the present invention will be described in detail below:

[0044] The self-driven tail nozzle mechanism provided in this embodiment of the invention can achieve real-time control of the tail nozzle opening by adaptively matching the propellant gas pressure throughout the entire launch cycle of the projectile 8 through the dynamic throttling diaphragm group 4, and has a dynamic control mechanism adapted to the internal flow field of the projectile 8 during launch.

[0045] When the projectile 8 is not launched, the self-driven control mechanism of the launch tube 1 does not operate, and the dynamic throttling diaphragm group 4 is closed due to the force of the return spring 3. During the initial propellant ignition stage of launch, the projectile 8 generates low gas pressure. The chamber pressure causes the actuator piston 6 to overcome a certain amount of the return spring 3 force, pushing the actuator piston 6 to move along the axis of the launch tube 1. This, through the spiral groove 601, drives the drive disk 5 to rotate, causing the dynamic throttling diaphragm group 4 to adjust its opening to balance the recoil. At this time, the opening is small, ensuring relatively complete combustion of the propellant gas while balancing the recoil through partial pressure relief. As the chamber pressure increases, the opening of the dynamic throttling diaphragm group 4 increases accordingly, exhibiting high adaptability. During the constant-volume combustion stage of the propellant, the chamber gas pressure rises rapidly, and the projectile 8 accelerates along the barrel 101. Under high pressure, it pushes the actuator piston 6 to its maximum stroke. At this time, the dynamic throttling diaphragm group 4 reaches its maximum opening, and the gas expands and accelerates through the tail nozzle 2 to form a jet, generating negative thrust to balance the recoil. In the aftereffect stage after the projectile 8 leaves the muzzle, the high-temperature and high-pressure gas continues to expand and accelerate in both directions along the muzzle and the tail nozzle 2. However, as the pressure inside the chamber is rapidly released, the recoil force generated by the gas gradually decreases. The self-driving control mechanism then adjusts accordingly. When the force of the gas on the actuator piston 6 is less than the spring force of the return spring 3, the actuator piston 6 moves towards the initial position. Through the spiral slide groove 601, it drives the drive disk 5 to rotate in the opposite direction, causing the dynamic throttling diaphragm group 4 to reduce the opening. Subsequently, the reduction of recoil force lowers the opening until there is no recoil, completing the entire process of projectile 8 launch and tail nozzle control.

[0046] In a further preferred embodiment, the present invention relies solely on the energy of the propellant gas itself to drive the control mechanism, without any other additional drive structure. Furthermore, it can dynamically match and control the nozzle opening according to the internal gas pressure to achieve the dual effects of improved energy efficiency and reduced recoil. This invention can be applied not only to the control of the tail jet flow in recoilless rifles, but also to scenarios involving nozzle opening control in rocket engines, aero engines, and other applications.

[0047] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. The quantity and shape of the guide holes 103, diaphragm 401, etc., described in the present invention are exemplary. The quantity, geometric parameters, and spatial arrangement of the technical features should be understood as non-limiting embodiments. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A self-driven control tail jet mechanism for a gravity-free cannon, comprising a launching barrel (1), a tail jet pipe (2), a reset spring (3), a dynamic throttling diaphragm group (4), a driving disc (5), an execution piston (6), a sealing ring (7), and a projectile (8), characterized in that: the front section of the launching barrel (1) is a barrel (101), the inner side of the barrel is a cannon bore (102), the rear end is provided with a jet pipe connecting groove (109) matched with a jet pipe connecting boss (201) of the tail jet pipe (2); a self-driven control cavity section (108) is arranged near the rear end face of the launching barrel (1), the inside of which is provided with two annular cavities, the front one is a piston movement cavity (104) in which the execution piston (6) is installed, the inner and outer walls near the rear end face of the execution piston (6) are respectively provided with an inner sealing groove (602) and an outer sealing groove (603), and the execution piston (6) is installed with a sealing ring (7) in each of the inner and outer sealing grooves (602, 603), the inner cavity of the execution piston (6) is a diaphragm movement platform (110), and the diaphragm movement platform (110) is provided with a plurality of diaphragm guide grooves (111) arranged in a circumferential annular manner; the rear one is a spring movement cavity (105) in which the reset spring (3) is installed; the driving disc installation groove (106) with a diameter slightly smaller than that of the reset spring (3) and the dynamic throttling diaphragm group installation groove (107) are arranged in sequence between the two cavity sections, the driving disc (5) is installed in the driving disc installation groove (106), and the dynamic throttling diaphragm group (4) is installed in the dynamic throttling diaphragm group installation groove (107); the piston movement cavity (104) and the cannon bore (102) are connected through a plurality of flow guide holes (103); and the projectile (8) is installed in the cannon bore (102) for launching; the dynamic throttling diaphragm group (4) is composed of a plurality of fan-shaped diaphragms (401) circumferentially arrayed and nested and matched with each other through side connection bosses (404) and side connection sliding grooves (405), the front end of each diaphragm (401) is provided with a diaphragm sliding groove (403) matched and connected with a guide boss (501) on the driving disc (5), the rear end of each diaphragm (401) is provided with a diaphragm sliding platform (402) matched with a diaphragm guide groove (111) on the diaphragm movement platform (110) to realize the rotary movement of the diaphragm (401); the helical sliding platform (502) circumferentially arranged on the driving disc (5) is matched and connected with the helical sliding groove (601) of the execution piston (6) to realize the rotary movement of the driving disc (5) and transmit the load to the diaphragm (401) to realize the linkage of the dynamic throttling diaphragm group (4). The self-driven control cavity section (108) is divided into two sections connected in sequence, the inner cavity of the front section is the piston movement cavity (104), and the inner cavity of the rear section is the spring movement cavity (105); the front part of the piston movement cavity (104) has a transition section which is a flow guide hole (103), the spring movement cavity (105) is in the shape of a circular tube as a diaphragm movement platform (110), and a plurality of diaphragm guide grooves (111) are circumferentially arrayed on the front end face of the diaphragm movement platform (110) and matched and connected with the diaphragm sliding platform (402) on the diaphragm (401).

2. The self-actuated tail-jet mechanism for a seatless cannon of claim 1, wherein: ​ 3. The self-actuated tail-jet mechanism for a seatless cannon of claim 1, wherein: The execution piston (6) is two-stage circular tube, the inner diameter of the front stage is smaller than the rear stage, the front stage is provided with inner sealing groove (602) and outer sealing groove (603) with same size, the outer side is provided with two outer sealing grooves (603), and sealing ring (7) is installed, the rear stage is provided with inner and outer through spiral slide groove (601) in circumferential array, which cooperates with spiral slide table (502) arranged along the circumference of the driving disc (5), and converts the axial movement of the execution piston (6) into the radial movement of the diaphragm (401) of the dynamic throttling membrane group (4).

4. The self-actuated tail-jet mechanism for a seatless cannon of any of claims 1-3, wherein: The elastic body (8) is forwardly moved along the axis of the launching cylinder (1) under the action of the gas pressure in the bore (102) in the initial ignition stage, the execution piston (6) overcomes the elastic force of the reset spring (3) and is forwardly actuated along the axis of the launching cylinder (1), drives the driving disc (5) to rotate through the spiral slide groove (601), and makes the dynamic throttling membrane group (4) linkage control a certain opening degree.

5. The self-actuated tail-jet mechanism for a seatless cannon of any one of claims 1-3, wherein: The gas pressure in the bore (102) rapidly decreases after the elastic body (8) is separated from the muzzle, the acting force of the gas on the execution piston (6) is smaller than the elastic force of the reset spring (3), the execution piston (6) is reversely actuated along the axis, drives the driving disc (5) to reversely rotate through the spiral slide groove (601), makes the dynamic throttling membrane group (4) linkage reduce the opening degree, and the dynamic throttling membrane group (4) also returns to the closed state with the execution piston (6) returning to the initial position under the action of the elastic force of the reset spring (3).

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