A dual-path, bidirectional inertial ignition airburst fuze for small-caliber projectiles

Abstract

The present invention discloses a dual-path, bidirectional inertial ignition air-burst fuze for small-caliber artillery projectiles, comprising an upper body, a main body, a safety and release explosion-proof mechanism, a delay body, a cover plate, a detonator tube, a first delay tube, a second delay tube, two percussion caps, two needle percussion caps, two springs, and two firing pins. It adopts dual-path redundant bidirectional inertial ignition and is provided with two delay tubes of different sizes in the fuze, thereby avoiding misfires of the fuze due to common cause failure as much as possible, while reducing the delay time dispersion and improving the timing accuracy of air-burst. The firing pin is not fixed and can rush forward to fire when the projectile hits the ground, thereby improving the comprehensive firing rate and reducing unexploded ammunition. The lower end structure of the delay body corresponding to the dual-path inertial ignition mechanism is closed, which is conducive to preventing crossfire and thus preventing ballistic explosion. The firing pin is of the same mass as or slightly heavier than the percussion cap component, thereby achieving safe landing and high performance optimization.

Description

Technical Field

[0001] The invention belongs to the technical field of fuzes, and in particular relates to a dual-path, bidirectional inertial ignition air-burst fuze for a small-caliber artillery projectile. Background Art

[0002] Small-caliber artillery shells generally range from 20mm to 40mm, launched from artillery to achieve damage, blasting, penetration, or other tactical purposes. Small-caliber artillery shells experience significant overload, and the electronic components and circuits used in their fuse timing are not shock-resistant, making reliability difficult to guarantee.

[0003] Small-caliber artillery shell airburst fuzes mostly use an inertial ignition mechanism and a time powder disc in the bore to achieve ignition and delay functions. However, the time powder disc has the following disadvantages: large time dispersion, low high-altitude reliability, short action time, and unsuitable for long-term storage.

[0004] Therefore, the technical key to the air burst fuze of small-caliber artillery projectiles is to improve the reliability of action and the accuracy of delay time.

[0005] To address these key technical challenges, domestic researchers have conducted extensive research. In their paper, "Time Accuracy Analysis of a Parallel Fuze Timer System" (published in "Pyrotechnics," Issue 2, 2006), Wen Quan et al. from Nanjing University of Science and Technology proposed that a fuze system using two parallel timers minimizes system operating time dispersion and improves accuracy by 17.42% compared to a single timer. In contrast, systems with three or more parallel timers experience increasing reliability as the number of timers increases, but the accuracy dispersion only increases slightly with the number of parallel timers. Therefore, if space permits, a system with two parallel timers is preferable, balancing cost, accuracy, and reliability. Chinese Patent 201220363259.9 utilizes dual ignition and detonation channels for reliable operation, but each channel lacks a flameproof mechanism, posing a significant risk of chamber explosion. Chinese Patent 201610952063.6 utilizes a dual firing mechanism, improving ignition reliability. However, the firing pin in its inertial firing mechanism is fixed, and the cartridge delay mechanism has two parallel, independent combustion channels. However, the use of a time cartridge as the delay mechanism results in low delay accuracy, and the firing and delay mechanisms are separate, occupying a large space. In summary, common problems with the prior art include low reliability, poor timing accuracy, and insufficient safety for small-caliber projectile airburst fuzes. Summary of the Invention

[0006] The purpose of the present invention is to provide a small-caliber artillery projectile warhead air burst fuze with dual-path bidirectional inertial ignition, which has a simple structure, high reliability and safety, and good time accuracy.

[0007] The technical solution for achieving the purpose of the present invention is as follows: a dual-path, bidirectional inertial ignition small-caliber artillery warhead air-burst fuze, comprising an upper body, a main body, a safety and explosion-proof release mechanism, a delay body, a cover plate, a detonator tube, a first delay tube, a second delay tube, two primer seats, two needle primers, two springs, and two firing pins. The upper body is coaxially arranged with the main body, and the upper part of the main body extends into the lower part of the upper body and the two are fixedly connected to form a fuze shell, a cavity is formed inside the fuze shell; the delay body is arranged in the cavity; the delay body is provided with two groups of stepped through holes and two cylindrical blind holes along the radial direction deviating from the axis, namely the first group of stepped through holes, the second group of stepped through holes, the first cylindrical blind hole, and the second cylindrical blind hole; each cylindrical blind hole is provided with a primer seat, a needle primer, a spring and a firing pin in sequence from top to bottom; a fire transmission groove is provided between the first group of stepped through holes and the second group of stepped through holes at the bottom of the delay body, and the first group of stepped through holes and the second group of stepped through holes are both connected It is a three-step through hole with a diameter decreasing from top to bottom. The first group of stepped through holes are called the first step hole, the second step hole, and the third step hole in sequence, and the second group of stepped through holes are called the fourth step hole, the fifth step hole, and the sixth step hole in sequence. The first delay tube is located in the second step hole, and the input end of the first delay tube faces upward and is fixed to the delay body by spot rivets. The second delay tube is located in the fifth step hole, and the input end of the second delay tube faces upward and is fixed to the delay body by spot rivets; the circumferential outer wall of the primer seat is respectively matched with the wall of the cylindrical blind hole in which it is located, and the needle end of the needle cap is downwardly arranged in the center hole of the primer seat, one end of the spring is against the primer seat, and the other end is against the firing pin, and the tip of the firing pin is facing upward; a groove is provided on the upper end surface of the delay body, and the cover plate is fixed in the groove by spot rivets and fixes the primer seat, the needle cap, the spring and the firing pin in the cylindrical blind hole of the delay body respectively; the safety and release explosion-proof mechanism and the detonator tube are all arranged in the main body.

[0008] The firing pin is not fixed axially. If both percussion caps fail to fire during projectile firing, the forward force of the projectile upon landing will cause the two firing pins to re-engage their respective percussion caps, thus triggering forward firing. This allows the firing mechanism to fire both forward and backward, increasing the overall firing rate of the fuze and helping to reduce unexploded ordnance.

[0009] The bottom structure of the cylindrical blind hole on the delay body that accommodates the dual-path inertial ignition mechanism is closed, which is beneficial to preventing crossfire and further preventing ballistic explosion.

[0010] The primer seat and the needle-pierced primer inside it together constitute the primer component. The mass of the primer component is the same as that of the firing pin, or the mass of the primer component is taken as two-thirds of the mass of the firing pin, so as to achieve high performance optimization of safety drop within the limited component height size limit.

[0011] The two primer holders and the two needle primers are identical to facilitate production management. The first and second delay tubes can be identical to facilitate production management. The first and second delay tubes can also be as different as possible to eliminate common cause failures and common mode failures and improve reliability.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) The inner cavity of the upper body of the present invention is provided with a pressure relief cavity with sufficient structural strength, which is beneficial to the stability of combustion and delay time.

[0014] (2) The present invention adopts two-way parallel ignition and two-way parallel timed ignition. Each ignition mechanism can ignite two-way timed ignition. The delay element is a closed tubular structure with high reliability and good time accuracy.

[0015] (3) The firing pin is not fixed in the axial direction. If both needle percussion caps fail to fire during firing, the firing pin can still fire when the projectile lands, achieving double-action redundant firing, improving the overall firing rate of the fuze, and reducing unexploded ordnance.

[0016] (4) The bottom structure of the blind hole on the delay body that accommodates the dual-path inertial ignition mechanism is closed, which helps to prevent crossfire and thus prevent ballistic explosion.

[0017] (5) The firing pin and the percussion cap are of the same mass or the firing pin is slightly heavier than the percussion cap, which is conducive to achieving safety and high performance optimization. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a main sectional view of the dual-path, bidirectional inertial ignition small-caliber artillery projectile air burst fuze of the present invention.

[0019] Figure 2 The figure is a side sectional view of the dual-path bidirectional inertial ignition small-caliber artillery projectile warhead air burst fuze of the present invention.

[0020] Figure 3 This is an axonometric view of the cover plate in the small-caliber artillery projectile air burst fuze with dual-path, bidirectional inertial ignition according to the present invention.

[0021] In the figure, 1 is the upper body, 2 is the main body, 3 is the safety and release explosion-proof mechanism, 4 is the delay body, 5 is the cover plate, 6 is the primer seat, 7 is the needle primer, 8 is the spring, 9 is the firing pin, 10 is the detonator tube, 11 is the first delay tube, 12 is the second delay tube; 31 is the ball rotor explosion-proof and delayed release explosion-proof mechanism, 32 is the open ring, 33 is the recoil safety mechanism, 34 is the ball seat; 311 is the isolation ball, 312 is the two-way input flame detonator, 313 is the gasket; 331 is the safety pin, 332 is the safety plate, 333 is the bracket. DETAILED DESCRIPTION

[0022] The present invention will be described in further detail below with reference to the accompanying drawings.

[0023] Combine Figures 1 to 3 The present invention relates to a dual-path, bidirectional, inertial ignition, small-caliber artillery projectile air-burst fuze, comprising an upper body 1, a main body 2, a safety and release explosion-proof mechanism 3, a delay body 4, a cover 5, a detonator tube 10, a first delay tube 11, a second delay tube 12, two percussion cap seats 6, two needle percussion caps 7, two springs 8, and two firing pins 9. The upper body 1 is coaxially arranged with the main body 2, and the upper part of the main body 2 extends into the lower part of the upper body 1, and the two are fixedly connected to form a fuze shell, the interior of which forms a cavity; the delay body 4 is provided with In the cavity; the delay body 4 is provided with two groups of stepped through holes and two cylindrical blind holes along the radial direction deviating from the axis, namely the first group of stepped through holes, the second group of stepped through holes, the first cylindrical blind hole and the second cylindrical blind hole. Each cylindrical blind hole is provided with a primer seat 6, a needle primer 7, a spring 8 and a firing pin 9 in sequence from top to bottom. A fire transfer groove is provided between the first group of stepped through holes and the second group of stepped through holes at the bottom of the delay body 4 to connect them. The first group of stepped through holes and the second group of stepped through holes are both from top to bottom. The first group of stepped through holes is sequentially called the first step hole, the second step hole, and the third step hole, and the second group of stepped through holes is sequentially called the fourth step hole, the fifth step hole, and the sixth step hole. The first delay tube 11 is located in the second step hole, and the input end of the first delay tube 11 is fixed to the delay body 4 by spot riveting. The second delay tube 12 is located in the fifth step hole, and the input end of the second delay tube 12 is fixed to the delay body 4 by spot riveting. The outer circumference of the primer seat 6 The walls are respectively matched with the clearances of the cylindrical blind holes in which they are located. The needle-piercing primer 7 is arranged in the center hole of the primer seat 6 with the needle-piercing end facing downward. One end of the spring 8 is against the primer seat 6, and the other end is against the firing pin 9, and the tip of the firing pin 9 is facing upward. The upper end surface of the delay body 4 is provided with a groove, and the cover plate 5 is fixed in the groove by spot riveting and fixes the primer seat 6, the needle-piercing primer 7, the spring 8 and the firing pin 9 in the cylindrical blind holes of the delay body 4 respectively. The safety and explosion-proof release mechanism 3 and the detonator tube 10 are both arranged in the main body 2.

[0024] The firing pin 9 is not fixed axially. If both needle-piercing primers fail to fire when the projectile is fired from the chamber, the two firing pins will be affected by the forward force when the projectile lands, and the two firing pins will be re-pierced by the respective needle-piercing primers to achieve forward firing. That is, the ignition mechanism has a recoil and forward dual-action firing function, which improves the overall firing rate of the fuze and helps reduce unexploded ordnance.

[0025] The bottom structure of the cylindrical blind hole on the delay body 4 that accommodates the dual-path inertial ignition mechanism is closed, which is beneficial to preventing crossfire and further preventing ballistic explosion.

[0026] The primer seat 6 and the needle-pierced primer 7 therein constitute the primer component. The mass of the primer component is the same as that of the firing pin 9, or the mass of the primer component is two-thirds of the mass of the firing pin 9, so as to achieve high performance optimization of safety drop within the limited component height size limit.

[0027] The two primer seats 6 and the two needle primers 7 are identical to each other, so as to facilitate production management.

[0028] The first extension tube 11 and the second extension tube 12 can be made completely identical to facilitate production management.

[0029] The first delay tube 11 and the second delay tube 12 may also be as different as possible to eliminate common cause failure and common mode failure and improve reliability.

[0030] During the service handling phase, any credible shocks and vibrations, including drops, bumps, and transportation shocks, will not cause the fuze to change its assembled state. When the fuze head falls downward, the firing pin 9, because it is not axially fixed, will approach the percussion cap assembly consisting of the percussion cap seat 6 and the percussion cap 7 therein. However, due to the spring resistance and the short duration of the drop impact, the firing pin 9 will not pierce the percussion cap 7. If the impact of a drop is unexpectedly severe, causing the firing pin to pierce the primer cap 7, the recoil safety mechanism 33 (safety pin 331 and safety plate 332) and the split ring 32 in the fuze, which are responsible for safety and release of the explosion-proof mechanism, are in the safe position, ensuring that the ball rotor explosion-proof and delayed-release explosion-proof mechanism 31 (including the isolation ball 311, the two-way flame detonator 312, and the gasket 313) is in an explosion-proof state. In this case, even if one or all of the two-way flame detonators 312 in the fuze accidentally ignite, no dangerous fragments will be generated, and the booster tube 10 will not be detonated. No high-temperature, high-pressure gaseous products will escape the fuze and enter the projectile explosive chamber. Neither the fuze booster charge nor the projectile will accidentally ignite, ensuring safety during the handling phase. The same consequences will occur if the firing pin pierces the primer cap 7, the first delay tube 11, the second delay tube 12, or the flame detonator 312 accidentally ignites.

[0031] When the projectile is fired, under the action of recoil, the safety pin 331 will shear the safety piece 332 and move downward until the safety pin 331 no longer protrudes and is stuck in the outer contour of the isolation ball 311, falling into the blind hole of the bracket 333, thereby releasing the safety of the isolation ball 311.

[0032] At the same time, under the action of recoil, the primer seat 5 and the needle primer 7 compress the spring 8 and move axially downward relative to the main body 1 until the needle primer 7 collides with the firing pin 9. The firing pin tip of the firing pin 9 penetrates the input end of the needle primer 7, and the needle primer 7 ignites. The flame gas output from its output end enters the empty chamber in the upper body 1 through the first cylindrical blind hole and the second cylindrical blind hole and expands, and then passes through the first step hole and the fourth step hole to the input end of the first delay tube 11 and the second delay tube 12, igniting the first delay tube and the second delay tube respectively, and the delay charge in the first delay tube and the second delay tube starts to burn timing.

[0033] As the projectile approaches the muzzle and its rotational speed approaches maximum, centrifugal force exerts on the split ring halves, causing them to open in the form of centrifugal torque, thereby releasing another safety feature on the isolation ball 311. Before the projectile reaches the end of its aftereffect phase, the recoil overload causes the isolation ball 311 to press against the ball seat 34. The resulting frictional torque forces the isolation ball 311 into an assembled state. Once the projectile passes the aftereffect phase and enters the outer ballistic phase, the recoil overload disappears. While the projectile is subject to creep overload, it is minimal and has minimal impact on the movement of the isolation ball 311. Thereafter, the isolation ball 311 rotates under the action of centrifugal torque and rotates to the alignment position, i.e., the explosion-proof position, beyond the safe separation distance for the projectile to fly out of the muzzle (usually 10 meters for small-caliber artillery shells). At this time, the two-way input flame detonator 312 at one end of the isolation ball 311 faces the central fire transmission hole at the bottom of the spherical hole of the body 2, and the two-way input flame detonator 312 at the other end faces the booster tube 10. The axis of the two-way input flame detonator 312 coincides with or nearly coincides with the axis of the projectile.

[0034] When the delay charge in the first delay tube and the second delay tube is completely burned, the timing ends, and the flame is transmitted to the two-way input flame detonator 312 in the safety and release explosion-proof mechanism 3 below it through the fire transmission hole and the fire transmission groove below the delay body 4. After the two-way input flame detonator 312 is ignited, it detonates the other two-way input flame detonator 312 opposite to it, and then detonates the booster tube 10, completing the detonation work.

[0035] If any one of the needle-piercing primers 7 fails to ignite, the remaining other needle-piercing primer 7 will ignite normally, and then the two delay tubes will be ignited at the same time through the expansion effect of the air chamber, without affecting the ignition reliability.

[0036] If one of the first delay tube 11 and the second delay tube 12 fails to be ignited accidentally, since the present invention is provided with two delay tubes, normal delay function and subsequent normal function can also be guaranteed.

[0037] If both firing pins 9 fail to trigger the needle-piercing primer 7 during the firing phase, since the firing pin 9 is not fixed, it can rush forward and poke the primer again when the projectile hits the ground to ignite it, thereby achieving double-action redundant ignition, thereby improving the comprehensive ignition rate of the fuze and reducing unexploded ammunition.

[0038] If the ball rotor explosion-proof and delayed-release explosion-proof mechanism 31 is accidentally misaligned, then during the predetermined ignition action, the flame products of the delay tube will pass through the gap between the isolation ball 311 and its chamber and the radial fire-transmitting holes preset on the isolation ball 311, reliably igniting any one of the two two-way input flame detonators 312 in the misaligned isolation ball 311, or igniting both of them simultaneously. The two two-way input flame detonators 312 in the isolation ball 311 will also detonate each other, but will not detonate the booster tube. At this time, the fuze loses its normal detonation function and enters a fire-proof state, thereby ensuring the safety of explosive disposal of unexploded ammunition caused by fuze misfires.

Claims

1. A dual-path, bidirectional inertial ignition airburst fuze for small-caliber projectiles, characterized by: The invention comprises an upper body (1), a main body (2), a safety and explosion-proof release mechanism (3), a delay body (4), a cover plate (5), a detonator tube (10), a first delay tube (11), a second delay tube (12), two primer seats (6), two needle primers (7), two springs (8), and two firing pins (9). The upper body (1) and the main body (2) are coaxially arranged, and the upper part of the main body (2) extends into the lower part of the upper body (1), and the two are fixedly connected to form a fuze shell, and a cavity is formed inside the fuze shell; the delay body (4) is arranged in the cavity; the delay body ( 4) Two groups of stepped through holes and two cylindrical blind holes are opened along the radial direction away from the axis, namely the first group of stepped through holes, the second group of stepped through holes, the first cylindrical blind hole and the second cylindrical blind hole. A primer seat (6), a needle primer (7), a spring (8) and a firing pin (9) are sequentially arranged in each cylindrical blind hole from top to bottom. A fire transfer groove is opened at the bottom of the delay body (4) between the first group of stepped through holes and the second group of stepped through holes to connect them. The first group of stepped through holes and the second group of stepped through holes are three-step through holes with decreasing diameters from top to bottom. The first group of stepped through holes and the second group of stepped through holes are three-step through holes with decreasing diameters from top to bottom. The first group of stepped through holes is sequentially called the first step hole, the second step hole, and the third step hole, and the second group of stepped through holes is sequentially called the fourth step hole, the fifth step hole, and the sixth step hole, the first delay tube (11) is located in the second step hole, the input end of the first delay tube (11) is upwardly fixed to the delay body (4) by spot riveting, the second delay tube (12) is located in the fifth step hole, the input end of the second delay tube (12) is upwardly fixed to the delay body (4) by spot riveting; the outer circumferential wall of the primer seat (6) and the cylindrical blind hole wall where it is located are respectively The needle-piercing primer (7) is arranged in the center hole of the primer seat (6) with the needle end facing downward, one end of the spring (8) abuts against the primer seat (6), and the other end abuts against the firing pin (9), and the tip of the firing pin (9) faces upward; the upper end surface of the delay body (4) is provided with a groove, and the cover plate (5) is fixed in the groove by spot riveting to fix the primer seat (6), the needle-piercing primer (7), the spring (8) and the firing pin (9) in the cylindrical blind hole of the delay body (4) respectively; the safety and release explosion-proof mechanism (3) and the detonator (10) are both arranged in the body (2).

2. The dual-path, bidirectional inertial ignition small-caliber artillery projectile airburst fuze according to claim 1, characterized in that: The cylindrical blind hole bottom structure on the delay body (4) that accommodates the primer seat (6), the needle primer (7), the spring (8) and the firing pin (9) is closed.

3. The dual-path, bidirectional inertial ignition small-caliber artillery projectile airburst fuze according to claim 1, characterized in that: The primer seat (6) and the needle-pierced primer (7) therein together constitute a primer component, and the mass of the primer component is the same as the mass of the firing pin (9), or the mass of the primer component is two-thirds of the mass of the firing pin (9).

4. The dual-path, bidirectional inertial ignition small-caliber artillery projectile airburst fuze according to claim 1, characterized in that: The two primer seats (6) and the two needle primers (7) are identical, which facilitates production management.

5. The dual-path, bidirectional inertial ignition small-caliber artillery projectile airburst fuze according to claim 1, characterized in that: The first extension tube (11) and the second extension tube (12) are completely identical, facilitating production management.

6. The dual-path, bidirectional inertial ignition small-caliber artillery projectile airburst fuze according to claim 1, characterized in that: The first delay tube (11) and the second delay tube (12) are different to prevent common cause failure and common mode failure.

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