A machine electric initiation fuse with self-destruction and standby trigger function for cannon shell

Abstract

The application discloses a rifled cannon shell bottom machine electric initiation fuze with self-destruction and standby trigger function, mainly comprising a fuze upper body, a body, a ball seat, an end cover, a gland, a centrifugal safety mechanism, a recoil safety mechanism, an explosion-proof mechanism, a power generation assembly, an electricity receiving assembly, an electric trigger assembly, a detection and firing control electronic assembly and a transmission explosion sequence. The centrifugal safety mechanism and the recoil safety mechanism constitute a redundant safety mechanism, and together with the explosion-proof mechanism, constitute a safety and isolation release mechanism. The explosion-proof mechanism has a delay release explosion-proof function; the recoil safety mechanism has a centrifugal self-destruction and standby mechanical trigger function; the power generation assembly generates electricity by using a recoil environment; the detection and firing control electronic assembly can detect geomagnetic signals, can realize distance air burst according to setting, can also consider timing self-destruction or dead fire, and can also realize electric trigger firing by cooperating with the electric trigger assembly. The fuze can be adapted to a rifled recoilless cannon shell grenade.

Description

Technical Field

[0001] This invention pertains to fuse technology, specifically relating to an electromechanical detonation fuse for the base of a rifled projectile with self-destruct and backup triggering functions. Background Technology

[0002] Since the 1970s, lightweight recoilless rifles have undergone further development, and their combat applications have continuously expanded. This has led to a greater variety of recoilless rifle ammunition types, further promoting the development and improvement of fuse structures and performance. In future warfare, the development of recoilless rifle fuse systems is of paramount importance to meet diverse operational needs.

[0003] According to "Fuse Construction and Function" (Ma Baohua, Fuze Construction and Function [M]. Beijing: National Defense Industry Press, December 1984), the US recoilless gun projectile fuses include the M557, M530A1, M90A1, and M91A1. The M557 fuse is a mechanically triggered fuse, primarily used for medium and large caliber artillery shells, but also suitable for recoilless gun shells. However, it is relatively large and not well-suited for recoilless gun shells. The M530A1 fuse is a non-rotating projectile fuse, meaning it is not a rifled projectile fuse. The construction and operating principles of the M90A1 and M91A1 fuses are as follows:

[0004] The M90A1 mechanical fuze is designed for use with 57mm recoilless rifle armor-piercing projectiles. The fuze body has a contact-activated indenter at the front, a cavitation detonator at the bottom, and a rotating detonator holder in a misaligned position with a flame detonator in the middle. This fuze has only a single centrifugal safety feature. After the recoil dissipates upon firing, the detonator holder rotates to its normal position under centrifugal torque. Upon impact with the target, the contact-activated indenter ignites, triggering the detonator, which in turn detonates the detonator, causing the projectile to detonate. This fuze does not meet the requirements for redundant safety design, lacks delayed release blast protection, and does not have a self-destruct function, making its safety difficult to guarantee.

[0005] The M91A1 fuze was originally designed for armor-piercing projectiles fired from 75mm and 105mm caliber howitzers, and was later adopted for high-explosive fragmentation (HE-FRAG) projectiles fired from rifled recoilless rifles. It is a blast-proof base fuze, consisting of an inertial triggering mechanism, a blast-proof mechanism, and a detonation sequence. During firing, the centrifugal force component along the axis of the centrifugal slide is insufficient to overcome the various resistances along the axis, so the slide remains in the blast-proof position. After the projectile leaves the muzzle, the recoil decreases, and the centrifugal inertial force increases. Under the action of the centrifugal inertial force, the two centrifugal springs compress and fly to both sides, releasing the firing pin. Simultaneously, the firing pin, whose center of gravity is off-center from the projectile axis, rotates around its axis until one side of the firing pin abuts against the slide tube, at which point the firing pin is aligned with the detonator. After the firing pin assembly is released from safety, the slide will also move under the action of the axial component of the centrifugal inertial force until the detonating charge is aligned with the detonator, putting the fuze in a ready-to-fire state. Upon impact with the target, the entire firing pin assembly, under the action of forward thrust, compresses the intermediate safety spring and strikes the detonator, which then ignites and detonates the projectile. This fuze has insufficient reliability at small or large angles of impact, lacks ground-penetrating detonation capability, and its safety release environment is limited to a centrifugal environment. It lacks redundant safety features and explosion-proof characteristics, and its self-destruct and flame-extinguishing functions are not considered.

[0006] According to the "Review of Fuze Technology for the Swedish Carl Gustav Recoilless Gun" (Journal of Detection and Control, Vol. 40, No. 4, 2018, pp. 34-39), the Swedish Carl Gustav anti-tank weapon system (i.e., the 84mm recoilless gun) uses the following fuzes: ZTZ42A1, FFV957, FFV502, FFV447, and F / 551. Their construction and operating principles are as follows:

[0007] The ZTZ42A1 time-delay fuze, used in the Type 545B illuminating round, is a time-delay disc fuze with in-bore inertial needle ignition. The detonation sequence consists of a percussion cap, igniter, delay disc, propellant grain, and propellant. Upon launch, recoil compresses the hammer's spring, causing the percussion cap to strike the impact pin. The igniter then ignites the delay disc, whose burning time is the flight time to the fuze's set distance. The propellant grain then ignites the propellant, which in turn ignites the illuminating agent within the round. The ZTZ42A1 fuze is a non-explosion-proof fuze, lacking explosion-proof characteristics, redundant safety features, and delayed release isolation features.

[0008] The FFV957 warhead trigger fuse is used with the Type 469B smoke grenade. Its instantaneous detonation sequence consists of a detonator, detonating cord, and detonating charge. Upon firing, recoil overload retracts the recoil pin in the safety and release mechanism, releasing the steel ball. The flange of the safety latch pushes the steel ball away from the channel and backward, then releases the slider. Centrifugal force then drives the slider radially outward, releasing the rotor. After release, the rotor, under centrifugal force, reaches the released position after a delay via a zero-return torque escapement mechanism. Centrifugal force also moves three circumferentially distributed spring safety pins outward, releasing the firing pin. Upon impact at a high angle, the firing pin ignites the detonator, then sequentially activates the detonating cord, detonating charge, dispersing charge, and smoke agent. Furthermore, upon direct head impact, the firing pin rod recoils, causing it to ignite the detonator. The fuse disarms the first safety mechanism through recoil overload and the second safety mechanism through rotation, meeting the requirements for explosion-proof, redundant safety, and delayed disarming isolation. The explosion-proof disarming distance is 20–70 m, and it has two modes of operation: triggering and ground-penetrating detonation.

[0009] The FFV502 base-detonating fuze is used with the Type 502 dual-purpose high-explosive and low-explosive fragmentation munition. Its instantaneous and delayed-detonation sequences both consist of a detonator, detonating charge, and detonating charge. Upon firing, propellant gas passes through the fuze base hole, pushing a pressure piston. The pressure piston causes the safety pin to move upwards, then the steel ball moves to the side, simultaneously releasing the escapement locking pin. Recoil overload and the compression drive spring push the escapement locking pin downwards, releasing the escapement. A torsion spring then rotates the rotor, and recoil overload continues to push the firing pin downwards, releasing the rotor and the spring-loaded pin within it. The rotor-driven firing pin blocks the rotor lock. When the rotor has rotated 180° and the recoil acceleration disappears, the compression spring pushes the rotor-driven firing pin upwards, causing the rotor to rotate to the deactivated position via the rotor lock. Therefore, this fuze deactivates the first safety via recoil overload and the second safety via the propellant pressure-driven rotor lock, with a deactivation distance of 16–31 meters. The activation modes of delayed and instantaneous triggering depend on the azimuth of the ammunition loading (a difference of 180° azimuth angle). This fuze meets the requirements for explosion protection, redundant safety, and delayed explosion protection disengagement, but lacks self-destruct and fire-extinguishing functions.

[0010] The FFV447 mechanical time / instantaneous trigger fuse is a warhead fuse used with the Type 441B high-explosive fragmentation round. Both its instantaneous and delayed detonation sequences consist of a first detonator, a second detonator, a detonating cord, and a detonating charge. Upon firing, recoil overload causes the recoil pin to retract, releasing the ball. The outer edge of the safety latch pushes the ball open, releasing the slider. Centrifugal force then drives the slider radially outward, releasing the rotor. Simultaneously, centrifugal force causes three circumferentially distributed spring safety pins to move outward, releasing the firing pin. After the rotor is released, under centrifugal force, it moves to the released position after a certain delay via a clock mechanism. At the set time, the clock mechanism delays the hammer firing the first detonator. The overpressure of this detonator drives the firing pin of the live striker to ignite the second detonator, then activates the detonating cord, the detonating charge, and the rest of the detonation sequence. In the instantaneous or ground-penetrating phase, the safety and release device rushes towards the firing pin, triggering the detonation sequence. The fuze's first safety mechanism is a recoil safety, and its second safety mechanism is a centrifugal safety. The fuze meets the requirements for explosion-proof protection, redundant safety, and delayed explosion-proof disengagement. The explosion-proof disengagement distance is 20–70 m. It has no self-destruct or flameout functions. The activation mode is mechanical timed or instantaneous triggering, and it can be manually set, but ignition reliability cannot be guaranteed at small or large impact angles.

[0011] The F / 551 base-detonating fuze is designed for the Type 551 armor-piercing projectile. This fuze uses an electrically triggered ignition system, with an instantaneous detonation sequence consisting of an electric detonator and a PBXN-5 explosive charge. In the safe state, two spring-loaded sleeves (recoil pins) restrain the misaligned rotor in a safe position. Upon firing, recoil overload causes the two spring-loaded sleeves to retract, releasing the rotor. The rotor, aided by its release spring, rotates 270° to the deflagration-released position, and the contact spring presses the contact plate firmly against the electric detonator, closing the ignition circuit. When the projectile impacts the target head-on or from the side, a shock wave propagates, compressing five piezoelectric crystals and sending an electrical signal to detonate the detonator. The detonator then activates the detonation tube, finally igniting the explosive charge. The fuze includes a bridge rectifier composed of four diodes. When the projectile flies through the bushes, the lower voltage generated on the piezoelectric crystal due to the impact with the bushes is reduced in the rectifier, making the voltage delivered to the electric detonator insufficient to ignite it, thus achieving the fuze's insensitivity, i.e., low sensitivity performance. This fuze only utilizes the recoil overload environment to disarm, failing to meet the redundancy safety requirements, and the disarming distance is only 5-15m, failing to meet the delayed disarming requirement.

[0012] To understand current recoilless gun fuze technology, we selected "recoilless gun fuze" as the search term and searched the CNKI database for Chinese and foreign language articles, covering the period from January 1915 (the furthest searchable period) to November 2023. We retrieved seven unique articles. Of these seven articles, only the one titled "A Review of Swedish Gustav Recoilless Gun Fuze Technology" (Journal of Detection and Control, Vol. 40, No. 4, 2018, pp. 34-39) provided an overview of the structure and operating principle of recoilless gun fuzes.

[0013] In addition to the fuzes mentioned above, the US military standard manual MIL-HDBK-145C, "ACTIVE FUZE CATALOG," also introduces fuzes suitable for recoilless artillery shells, including the M503A2, M509A2, and M592A1 fuzes. The M503A2 and M509A2 fuzes are both impact fuzes and do not have a fixed-distance airburst capability. While the M592A1 fuze has a settable mode, allowing it to be set to delayed (timed) or muzzle 15m action, it is a non-explosion-proof fuze with insufficient safety features. None of these three fuzes have self-destruct or anti-flameout capabilities.

[0014] In summary, existing recoilless gun fuses generally suffer from problems such as low safety, poor reliability, difficulty in ensuring the safety of explosive disposal, complex structure, and excessive cost. Summary of the Invention

[0015] The purpose of this invention is to provide a rifled artillery shell base electromechanical detonation fuse with self-destruct and backup triggering functions. It has functions such as redundant safety, explosion protection, delayed explosion protection release, fixed-distance airburst, redundant triggering, redundant self-destruction, and fire suppression. It is mainly suitable for rifled recoilless gun projectiles.

[0016] The technical solution for achieving this invention is as follows: A rifled projectile base electromechanical detonation fuze with self-destruct and backup trigger functions, mainly comprising a fuze upper body, a main body, a ball seat, an end cap, a pressure cap, a centrifugal safety mechanism, a recoil safety mechanism, a flameproof mechanism, a power generation component, a power receiving component, an electric triggering component, a detection and ignition control electronic component, and a detonation transmission sequence. The flameproof mechanism is located in the middle of the fuze, within the cavity formed by the ball seat and the fuze upper body; the centrifugal safety mechanism is located in the upper half of the fuze, around the flameproof mechanism; the recoil safety mechanism is located in the lower half of the fuze, below the flameproof mechanism, within the cavity formed by the ball seat and the end cap; the flameproof mechanism and the recoil safety mechanism are together disposed within the fuze cavity formed by the fuze upper body and the main body; the power generation component, the power receiving component, the electric triggering component, and the detection and ignition control electronic component are all disposed within the annular cavity formed by the annular groove of the main body and the pressure cap; the detonation transmission sequence is arranged along the fuze axis, with a staggered flameproof section in the middle, a sensitive linear section at the bottom, and a blunt-sensitive section, i.e., the detonation transmission tube, at the top. The overall structure of the fuze mainly consists of two parts: a mechanical fuze section with a length-to-diameter ratio close to 2:1, primarily located within the mechanical fuze cavity formed by the fuze body and end cap; and an electromechanical fuze power generation and ignition control section with a length-to-diameter ratio approximately 1:2, primarily located within the annular cavity formed by the annular groove of the body and the pressure cap. The mechanical fuze section is connected to the electromechanical fuze power generation and ignition control section via external threads. Along the fuze axis, the mechanical fuze section comprises, from top to bottom, a detonation tube, a centrifugal safety mechanism, a blast-proof mechanism, and a recoil safety mechanism. The blast-proof mechanism also features delayed blast-proof disengagement, while the recoil safety mechanism combines inertial triggering and centrifugal self-destruction functions. The explosion-proof mechanism mainly includes a fuse upper body, an isolation ball, short firing pins, an isolation sleeve, a detonating charge, and a ball seat. The isolation ball, isolation sleeve, detonating charge, and two short firing pins constitute the ball rotor in the explosion-proof mechanism. The isolation sleeve is mainly used to enhance explosion-proof safety. The two short firing pins ensure the correct ignition of the ball rotor in the direction of rotation, which helps to obtain a longer delay in releasing the explosion-proof distance. The ball seat ring side is provided with radial pressure relief holes and axial pressure relief channels, which help to release the high-temperature and high-pressure gas generated by the accidental ignition of the needle detonator in the detonation sequence (13), thereby ensuring explosion-proof safety.The electromechanical fuse power generation and ignition control section includes a body, a pressure cap, a power generation component, a power receiving component, an electric triggering component, a detection and ignition control electronic component, an electric ignition tube, and an electric ignition tube seat. Ten axial holes are distributed along the axial direction within the annular groove of the body, sequentially arranged clockwise from the 12 o'clock position as: a first threaded hole, a second stepped through hole, a third stepped hole, a fourth threaded hole, a fifth stepped hole, a sixth threaded hole, a seventh stepped hole, an eighth stepped through hole, a ninth threaded hole, and a tenth threaded hole. The power generation component is located in the seventh stepped hole of the body. There are two power receiving components, respectively located in the second and eighth stepped through holes of the body. The electric triggering component is located in the third stepped hole of the body. The detection and ignition control electronic component is located on the left side of the annular groove of the body, connected to the first and ninth threaded holes of the body by two bolts. The holes are fixed; after the power generation component, the power receiving component, the electric trigger component, and the detection and ignition control electronic component are installed in the body, they are all potted with potting compound and fixed by the pressure cap through three screws to the fourth, sixth, and tenth threaded holes on the body; the motor weight in the power generation component is pushed by the recoil force to move the magnetic core of the recoil generator downward to generate electrical energy; the detection and ignition control electronic component can be set by the weapon system's setter before launch by the power receiving component below the fuse to the projectile revolutions corresponding to the predetermined airburst distance and the self-destruct time that meets tactical requirements. After launch, it can realize the fixed-distance airburst by detecting the geomagnetic signal to count the projectile revolutions, or realize timed self-destruction or extinguishing after the predetermined self-destruct time, or realize triggering ignition in conjunction with the electric trigger component, and realize self-discharge, that is, dissipation of electric ignition energy, after the fuse misfires.The electric ignition tube is ignited by the detection and ignition control component under the control of the fixed-distance airburst, electric trigger, or timed self-destruct signal. It directly detonates the needle detonator, which then detonates the detonating charge in the isolation ball after it is turned upright, and then detonates the detonating tube. If the isolation ball fails to turn upright and the explosion isolation is not released, the needle detonator will be detonated but the detonating charge will not be detonated, which will lead to a fire failure. If the fixed-distance airburst speed and self-destruct time are not set before launch, or if the detection and ignition control component fails to control the electric ignition tube to detonate normally, when the speed of the projectile decreases to the point that the centrifugal inertial force of the centrifugal ball is insufficient to support and balance the resistance of the inertial spring in the recoil safety mechanism (7), the inertial spring pushes the firing body in the recoil safety mechanism (7) to move forward axially, causing The needle detonator mounted above the firing body strikes the short firing pin below the isolation ball, which has been positively converted by centrifugal inertial force, and ignites, thus achieving centrifugal self-destruction of the fuze. After the fuze is released from isolation, before the count-based distance airburst, electronic timing self-destruction, and centrifugal self-destruction occur, if the projectile hits the target at a small or large angle of impact, the inertial trigger switch in the electric trigger assembly will be closed by the forward force, connecting the circuit and causing the fuze to be electrically triggered and ignited. If the projectile has already hit the target or target area, the firing body will carry the centrifugal ball and needle detonator along with the inertial spring forward, overcoming the constraint reaction force generated by the centrifugal ball along the self-destruction ramp, causing the needle detonator mounted on the firing body to strike the short firing pin below the isolation ball, which has been positively converted by centrifugal inertial force, and ignite, thus enabling the fuze to perform a backup inertial trigger function.

[0017] Compared with the prior art, the significant advantages of the present invention are:

[0018] (1) It has a fixed-distance airburst function, and the explosion distance can be predetermined by the external power pole assembly combined with a simple installation operation.

[0019] (2) It meets the requirements of explosion-proof, redundant insurance and delayed explosion-proof release, and has backup redundant triggering, redundant self-destruction and fire-extinguishing functions. It has good safety, high reliability and safe handling of unexploded ordnance and explosives.

[0020] (3) Simple structure and low cost. Attached Figure Description

[0021] Figure 1 This is a front sectional view of a rifled projectile base electromechanical detonation fuze with self-destruct and backup trigger functions, as described in this invention.

[0022] Figure 2 This is a top view of a rifled projectile base electromechanical detonation fuse with self-destruct and backup trigger functions, as described in this invention.

[0023] Figure 3 This is a view of the electromechanical detonator at the base of a rifled projectile with self-destruct and backup triggering functions, as described in this invention.

[0024] Figure 4 This is a cross-sectional view along section AA of a rifled projectile base electromechanical detonation fuse with self-destruct and backup trigger functions, as described in this invention.

[0025] Figure 5 This is a cross-sectional view along the BB section of a rifled projectile base electromechanical detonator with self-destruct and backup trigger functions, as described in this invention.

[0026] Figure 6 This is a cross-sectional view along the CC section of a rifled projectile base electromechanical detonation fuse with self-destruct and backup trigger functions, as described in this invention.

[0027] Figure 7 This is a cross-sectional view along the DD section of a rifled projectile base electromechanical detonation fuse with self-destruct and backup trigger functions, as described in this invention.

[0028] Figure 8 This is a cross-sectional view along the GG section of a rifled projectile base electromechanical detonation fuse with self-destruct and backup trigger functions, as described in this invention.

[0029] Figure 9 This is a cross-sectional view along section HH of a rifled projectile base electromechanical detonation fuse with self-destruct and backup trigger functions, as described in this invention.

[0030] Figure 10 This is a cross-sectional view along section KK of a rifled projectile base electromechanical detonation fuse with self-destruct and backup trigger functions, as described in this invention.

[0031] In the diagram, 1 is the fuse upper body, 2 is the fuse body, 3 is the ball seat, 4 is the end cap, 5 is the pressure cap, 6 is the centrifugal safety mechanism, 7 is the recoil safety mechanism, 8 is the explosion-proof mechanism, 9 is the power generation component, 10 is the power connection component, 11 is the electric triggering component, 12 is the detection and ignition control electronic component, 13 is the detonation sequence, 14 is the centrifugal cylinder, 15 is the centrifugal cylinder spring, 16 is the stop pin, 17 is the firing element, 18 is the centrifugal ball, 19 is the inertia spring, 20 is the isolation ball, 21 is the short firing pin, and 22 is... The detonating charge consists of: 23 (motor weight), 24 (guide sleeve), 25 (magnetic recoil generator), 26 (adjusting washer), 27 (safety plate), 28 (motor reinforcing seat), 29 (pressure screw), 30 (upper insulating sleeve), 31 (lower insulating sleeve), 32 (electric pole), 33 (switch mounting base), 34 (inertia trigger switch), 35 (electric ignition tube), 36 (electric ignition tube socket), 37 (potting compound), 38 (bolt), 39 (needle detonator), 40 (detonation transmission tube), 41 (screw), and 42 (isolation sleeve). Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In this embodiment of the invention, all directional indications (such as up, down, left, right, forward, backward, etc.) are only used to interpret specific postures (as shown in the attached diagram). Figure 1 The relative positions and movements of the components shown are as follows: if the specific posture changes, the directional indication will also change accordingly. Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0034] The following section will further introduce the specific implementation methods, as well as the technical difficulties and inventive points of this invention, using this design example as an example.

[0035] Combination Figures 1-10The present invention discloses a rifled projectile base electromechanical detonation fuse with self-destruction and backup triggering functions, which mainly includes a fuse upper body 1, a body 2, a ball seat 3, an end cap 4, a pressure cap 5, a centrifugal safety mechanism 6, a recoil safety mechanism 7, an explosion-proof mechanism 8, a power generation component 9, a power receiving component 10, an electric triggering component 11, a detection and ignition control electronic component 12, and a detonation sequence 13. Centrifugal safety mechanism 6 is located in the upper half of the fuse; recoil safety mechanism 7 is located in the cavity formed by ball seat 3 and end cap 4, and is also set together in the fuse cavity formed by fuse upper body 1 and body 2; ten axial holes are distributed circumferentially in the annular groove of body 2, starting from the twelve o'clock position and proceeding clockwise as the first threaded hole, second stepped through hole, third stepped hole, fourth threaded hole, fifth stepped hole, sixth threaded hole, seventh stepped hole, eighth stepped through hole, ninth threaded hole, and tenth threaded hole; power generation component 9 is set in the seventh stepped hole of body 2; there are two power connection components 10, which are respectively set in the second step of body 2. The through hole and the eighth step through hole; the electric trigger assembly 11 is set in the third step hole of the body 2; the detection and ignition control electronic assembly 12 is set on the left side of the annular groove of the body 2, and is fixed by two bolts 38 respectively connected to the first threaded hole and the ninth threaded hole on the body 2; after the power generation assembly 9, the power receiving assembly 10, the electric trigger assembly 11 and the detection and ignition control electronic assembly 12 are installed in the body 2, they are all potted with potting compound 37, and are fixed by the pressure cap 5 to the fourth threaded hole, the sixth threaded hole and the tenth threaded hole on the body 2 by three screws 41; the centrifugal safety mechanism 6 includes the fuse upper body 1 and the centrifugal cylinder 1. 4. Centrifuge cylinder spring 16 and stop pin 16: The upper half of the fuse body 1 has three stepped holes evenly arranged circumferentially. Each stepped hole is arranged from the outside to the inside as a first-step hole, a second-step hole, and a third-step hole. Inside the stepped holes, centrifuge cylinder 14, centrifuge cylinder spring 15, and stop pin 16 are arranged radially from the inside to the outside. The stop pin 16 is fixed in the second-step hole and the third-step hole by spot riveting or bonding. The bottom of the centrifuge cylinder 14 is inserted into the pre-set right-angle groove on the upper part of the isolation ball 20 to implement centrifugal safety. The recoil safety mechanism 7 includes a ball seat 3, an end cap 4, a firing body 17, a centrifuge ball 18, and an inertia spring 19. The end cap 4 is secured by its own external thread from bottom to top. The ball seat 3 is screwed in, and the top frustum of the firing body 17 is pushed into the shallow blind hole at the bottom of the isolation ball 20 by the inertia spring 19 to implement the recoil safety. There are 3 to 7 radial blind holes evenly distributed in the circumference of the upper part of the firing body 17, and a centrifugal ball 18 is set inside each radial blind hole. The explosion-proof mechanism 8 includes the fuse upper body 1, the ball seat 3, the isolation ball 20, the isolation sleeve 42, the short firing pin 21, and the detonating charge 22. The short firing pin 21 and the isolation sleeve 42 seal the detonating charge 22 inside the isolation ball 20. The ball seat 3 fixes the isolation ball 20 in the cavity of the fuse upper body 1 by means of the centrifugal safety mechanism 6 and the recoil safety mechanism 7.The power generation assembly 9 includes a motor weight 23, a guide sleeve 24, a magnetic recoil generator 25, an adjusting washer 26, a safety plate 27, and a motor reinforcing seat 28. The motor reinforcing seat 28 is located at the bottom of the seventh step hole of the main body 2. The safety plate 27 is located above the motor reinforcing seat 28 and is used to support the magnetic core of the magnetic recoil generator 25. The adjusting washer 26 is located above the safety plate 27 and is used to adjust and axially fix the coil of the magnetic recoil generator 25. The motor weight 23 is located above the magnetic core of the magnetic recoil generator 25 and is guided by the guide sleeve 24. The power connection assembly 10 includes a pressure screw 29, an upper insulating sleeve 30, a lower insulating sleeve 31, and a power connection rod 32. The upper part of the power connection rod 32 is screwed into the pressure screw 29, and the bottom surface of the pressure screw 29 is connected to the power connection rod 32. The middle part of the rod 32 is insulated from the side of the stepped through hole of the body 2 by an upper insulating sleeve 30, and the lower part of the connecting rod 32 is insulated from the side of the stepped through hole of the body 2 by a lower insulating sleeve 31. The electric trigger assembly 11 includes a switch fixing seat 33, an inertial trigger switch 34, an electric ignition tube 35, and an electric ignition tube seat 36. The inertial trigger switch 34 is fixed to the switch fixing seat by welding or riveting and is set together in the seventh stepped hole of the body 2. The detonation sequence 13 is arranged along the fuse axis, with the middle part being a misaligned detonating charge 22 located inside the isolation ball 20, the lower part being the sensitive straight section of the electric ignition tube 35 and the needle detonator 39, and the upper insensitive part being the detonation tube 40, which is fixed to the top of the fuse upper body 1 by screwing.

[0036] Furthermore, the overall structure of the fuse mainly comprises two parts: a mechanical fuse part with a length-to-diameter ratio of approximately 2:1, which is mainly located in the mechanical fuse cavity formed by the fuse upper body 1 and the end cap 4; and an electromechanical fuse power generation and ignition control part with a length-to-diameter ratio of approximately 1:2, which is mainly located in the annular cavity formed by the body 2 and the pressure cap 5. The mechanical fuse part is connected to the electromechanical fuse power generation and ignition control part by external threads.

[0037] Furthermore, the mechanical fuse section, from top to bottom along the fuse axis, consists of a detonation tube 40, a centrifugal safety mechanism 6, a flameproof mechanism 8, and a recoil safety mechanism 7. The flameproof mechanism 8 also has a delayed flameproof release function, and the recoil safety mechanism 7 has both an inertial triggering function and a centrifugal self-destruct function. The flameproof mechanism 8 mainly includes a fuse upper body 1, an isolation ball 20, short firing pins 21, an isolation sleeve 42, a detonating charge 22, and a ball seat 3. The isolation ball 20, isolation sleeve 42, detonating charge 22, and two short firing pins 21 form the ball rotor in the flameproof mechanism 8. The isolation sleeve 42 is mainly used to enhance the flameproof safety. The two short firing pins 21 ensure the correct firing of the ball rotor regardless of whether it is in the forward or reverse direction, which helps to obtain a longer delayed flameproof release distance. The ball seat 3 has radial pressure relief holes and axial pressure relief channels on the ring side, which helps to release the high-temperature and high-pressure gas generated by the accidental firing of the needle-punched detonator 39, thereby ensuring the flameproof safety.

[0038] Furthermore, the motor weight 23 in the power generation component 9 is pushed by the recoil force to make the magnetic core of the recoil generator move downward and generate electrical energy; the detection and ignition control electronic component 12 can be set by the weapon system's setter before launch by the power receiving component 10 below the fuse to the projectile revolutions corresponding to the predetermined airburst distance and the self-destruct time that meets tactical requirements. After launch, it can realize the fixed-distance airburst by detecting the geomagnetic signal to count the projectile revolutions, or realize timed self-destruction or extinguishing after the predetermined self-destruct time, or realize triggering ignition in conjunction with the electric trigger component 11, and realize self-discharge, that is, dissipation of electric ignition energy after the fuse misfires.

[0039] Furthermore, after the electric ignition tube 35 is ignited by the detection and ignition control component 12 under the control of the fixed-distance airburst, electric trigger, or timed self-destruct signal, it directly detonates the needle detonator 39. The needle detonator 39 then detonates the detonating charge 22 in the isolation ball 20 after it is turned upright, which in turn detonates the detonating tube 40. If the isolation ball 20 fails to turn upright and thus fails to release the explosion isolation, the needle detonator 39 will be detonated but will not detonate the detonating charge 22, which will cause the fuse to extinguish.

[0040] Furthermore, if the rotation speed and self-destruct time of the air-to-ground bomb are not set before launch, or if the detection and ignition control component 12 fails to properly control the electric ignition tube 35 to detonate, when the rotation speed of the bomb decreases to the point that the axial constraint reaction force generated by the centrifugal inertial force of the centrifugal ball 20 along the self-destruct inclined surface of the ball seat 3 is insufficient to support and balance the resistance of the inertial spring 19, the inertial spring 19 pushes the firing body 17 to move forward axially, causing the needle detonator 39 installed above the firing body 17 to strike the short firing pin 21 below the isolation ball 20, which has been turned upright by the centrifugal inertial force, and ignite, thus achieving centrifugal self-destruction of the fuse.

[0041] Furthermore, after the fuse is de-isolated, before the count-based distance airburst, electronic timing self-destruction, and centrifugal self-destruction occur, if the projectile hits the target at a small or large angle of impact, the inertial trigger switch 34 in the electric trigger assembly 11 will be closed by the forward force to connect the circuit, causing the fuse to be electrically triggered and ignited; if the projectile has already hit the target or target area, the firing body 17 will carry the centrifugal ball 20 and the needle detonator 39 on it, together with the inertial spring 19, to overcome the constraint reaction force generated by the centrifugal ball 20 along the self-destruction slope, causing the needle detonator 39 installed on the firing body 17 to strike the short firing pin 21 below the isolation ball 20, which has been turned upright by the centrifugal inertial force, and ignite it. The needle detonator 39 detonates the detonating charge 22 in the isolation ball 20 below the short firing pin 21, and then detonates the detonating tube 40, thus realizing the backup inertial triggering function of the fuse.

[0042] The challenge of this invention lies in the fact that the fuse utilizes the recoil environment after launch to generate its own power, enabling the detection and ignition control electronic components to function normally. By using the pre-set fixed-distance rotation number of the detection and ignition control electronic components, the invention detects the geomagnetic signal after launch to achieve the function of counting rotations and fixed-distance airburst. The explosion-proof mechanism also has the function of delayed release of explosion-proof, and has redundant safety, redundant triggering, redundant self-destruction and fire-extinguishing functions. The structure is ingenious, highly reliable, safe, and low in cost, and is suitable for rifled recoilless gun shells with low recoil overload.

[0043] Combination Figures 1-10 The principle of the electromechanical detonation fuse for a rifled projectile base with self-destruct and backup trigger functions is as follows:

[0044] Normally, the fuse is in its factory-assembled state, i.e., the explosion-proof safety state. The centrifugal cylinder 14, under the pre-compression resistance of the centrifugal cylinder spring 15, engages in a pre-set right-angle groove above the isolation ball 20, locking the isolation ball 20 and forming a centrifugal safety. The top frustum of the firing body 17, under the pre-compression resistance of the inertia spring 19, engages in a pre-set shallow blind hole below the isolation ball 20, locking the isolation ball 20 and forming a recoil safety. The detonating charge 22 inside the isolation ball 20 is misaligned with the electric ignition tube 35 and the needle detonator 39, ensuring explosion-proof safety. The explosion-proof mechanism 8 and its redundant safety mechanisms, consisting of the centrifugal safety mechanism 6 and the recoil safety mechanism 7, form the fuse's safety and de-isolation mechanism. Accidental impacts (including drop impacts), vibrations, and external stimuli generated during normal operation cannot cause the fuse to activate unexpectedly. In this state, even if the needle detonator 39 ignites accidentally, it will not detonate the detonating charge 22 or the detonation tube 40. The explosive charge in the detonating charge 22 and the detonating tube 40 is the permissible detonating charge JH-14C or JO-9C.

[0045] Before launch, the delay count of the detection and ignition control electronic component 12 needs to be set via the power rod 32 in the power connection component 10 below the fuse, so as to realize the count-and-distance airburst function after launch.

[0046] During launch, the motor weight 23 in the power generation assembly 9 moves downward due to the recoil environment, which in turn forces the magnetic core of the magnetic recoil generator 25 to break through the safety breaker 27 and move downward. The relative motion between the magnetic core and the coil of the magnetic recoil generator 25 generates electrical energy that is stored in the detection and firing control electronic assembly 12. At the same time, the firing body 17, which has 3 to 7 centrifugal balls 18 inside, moves axially backward due to the recoil environment, overcoming the resistance of the inertia spring 19. This causes the top frustum of the firing body 17 to be pulled out of the shallow blind hole at the bottom of the isolation ball 20. The centrifugal balls 18 are thrown out under the action of centrifugal inertia force and jam into the self-destructing inclined surface of the ball seat. The firing body 17 enters the unlocked state, which is also the ready state for centrifugal self-destruction and inertial triggering. The centrifugal cylinder 14 moves radially outward under the action of centrifugal inertia force, overcoming the resistance of the centrifugal cylinder spring 15. This causes the lower right corner of the centrifugal cylinder 14 to be pulled out of the right-angle slot at the top of the isolation ball 20, thereby releasing the isolation ball 20. The isolation ball 20 rotates inside the fuse cavity under the action of centrifugal inertial force. After a certain delay (corresponding to a projectile travel distance of more than 20m), the detonating charge 22 inside the isolation ball 20 is aligned with the lower penetrating detonator 39 and the upper detonating tube 40 respectively, thus releasing the explosion isolation. At this time, the fuse is in the ready-to-ignite state.

[0047] After launch, the fuze detection and ignition control electronic component 12 records the number of fuze rotations by detecting geomagnetic signals. When the preset number of rotations is reached, the fuze detection and ignition control electronic component 12 detonates the electric ignition tube 35, which in turn detonates the needle detonator 39 and the detonating charge 22 inside the upright isolation ball 20, and then detonates the detonation tube 40, finally detonating the main charge of the projectile, thus achieving a fixed-distance airburst by counting the number of fuze rotations.

[0048] If the fuse strikes the target, target area, or ground before reaching the set number of revolutions or if the number of revolutions fails, the inertial trigger switch 34 in the electric trigger assembly 11 will close due to the forward force of the impact and transmit a signal to the detection and ignition control electronic assembly 12 to control the detonation of the electric ignition tube 35. The subsequent function is the same as above, realizing the electric trigger function; or when the fuse strikes the target, the firing body 17 will overcome the resistance of the inertial spring 19 and move forward, causing the needle detonator 39 installed on the top of the firing body 17 to strike the short firing pin 21 below the rear isolation ball 20 and ignite. The subsequent function is the same as above, realizing the backup trigger function.

[0049] If the fuse does not hit the target before the set rotation speed is reached or the rotation speed counter fails, the detection and ignition control electronic component 12 will detonate the electric ignition tube 35 after the preset self-destruct time is reached. The subsequent function is the same as above, realizing the timed self-destruction. Or, before the preset self-destruct time is reached, when the projectile speed decreases to below the critical speed, the axial component of the centrifugal force generated by the centrifugal ball 18 along the self-destruct inclined plane is insufficient to resist the resistance of the inertial spring 19. The inertial spring 19 pushes the firing body 17 to move upward along the axis, causing the needle detonator 39 installed on the top of the firing body 17 to strike the short firing pin 21 below the upright isolation ball 20 and ignite. The subsequent function is the same as above, realizing the centrifugal self-destruction function.

[0050] The above-described process assumes that the fuze has been reliably deactivated from its explosion-proof barrier. If the fuze fails to deactivate the explosion-proof barrier, the above process will ignite the electric igniter 35 and the needle detonator 39, but will not detonate the detonating charge 22 and the detonation tube 40. The sensitive explosive elements of the fuze will then be detonated, and the fuze will enter an insulated state. Similarly, if the aforementioned fuze ignites unexpectedly without deactivating the explosion-proof barrier, the electric igniter 35 and the needle detonator 39 are both located in the same space formed by the firing body 17 and the electric igniter base 36, allowing them to detonate each other. The internal space is sufficient to release the pressure generated by the explosion. The detonating charge 21 is located inside the misaligned isolation sphere 20, and the energy generated by the unexpected ignition cannot be transferred to the detonating charge 21. At this point, the sensitive elements of the fuze have completed energy release, and the fuze is in an insulated state, ensuring the safety of handling unexploded ordnance and explosives.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rifled projectile base electromechanical detonation fuse with self-destruct and backup trigger functions, mainly comprising a fuse upper body (1), a main body (2), a ball seat (3), an end cap (4), a pressure cap (5), a centrifugal safety mechanism (6), a recoil safety mechanism (7), an explosion-proof mechanism (8), a power generation component (9), a power receiving component (10), an electric triggering component (11), a detection and ignition control electronic component (12), and a detonation sequence (13), characterized in that: The explosion-proof mechanism (8) is located in the middle of the fuse, in the cavity formed by the ball seat (3) and the upper body of the fuse (1); the centrifugal safety mechanism (6) is located in the upper half of the fuse, around the explosion-proof mechanism (8); the recoil safety mechanism (7) is located in the lower half of the fuse, below the explosion-proof mechanism (8), in the cavity formed by the ball seat (3) and the end cap (4); the explosion-proof mechanism (8) and the recoil safety mechanism (7) are together set in the fuse cavity formed by the upper body of the fuse (1) and the body (2); the power generation component (9), the power connection component (10), the electric trigger component (11) and the detection and ignition control electronic component (12) are all set in the annular cavity formed by the annular groove of the body (2) and the pressure cap (5); the detonation sequence (13) is set along the fuse axis, with the middle part being the staggered explosion-proof part, the lower part being the sensitive straight part, and the upper part being the insensitive part, i.e., the detonation tube (40). The overall structure of the fuse mainly consists of two parts: a mechanical fuse part with a length-to-diameter ratio of 2:1, which is mainly located in the mechanical fuse cavity formed by the fuse upper body (1) and the end cap (4); and an electromechanical fuse power generation and ignition control part with a length-to-diameter ratio of 1:2, which is mainly located in the annular cavity formed by the annular groove of the body (2) and the pressure cap (5); the mechanical fuse part is connected to the electromechanical fuse power generation and ignition control part by external thread; The mechanical fuse part consists of a detonation tube (40), a centrifugal safety mechanism (6), an explosion-proof mechanism (8), and a recoil safety mechanism (7) along the fuse axis from top to bottom. The recoil safety mechanism (7) includes a ball seat (3), an end cap (4), a firing body (17), a centrifugal ball (18), and an inertial spring (19). The end cap (4) is screwed into the ball seat (3) from bottom to top by its own external thread, and the top frustum of the firing body (17) is pushed into the shallow blind hole at the bottom of the isolation ball (20) by the inertial spring (19) to implement the recoil safety. There are 3 to 7 radial blind holes evenly distributed in the circumference on the upper part of the firing body (17), and a centrifugal ball (18) is set inside each radial blind hole. The explosion-proof mechanism (8) also has the function of delayed release of explosion-proof, and the recoil safety mechanism (7) also has the function of inertial triggering. It has the function of centrifugal self-destruction; the explosion-proof mechanism (8) mainly includes the fuse upper body (1), isolation ball (20), short firing pin (21), isolation sleeve (42), detonating charge (22) and ball seat (3). The isolation ball (20), isolation sleeve (42), detonating charge (22) and two short firing pins (21) form the ball rotor in the explosion-proof mechanism (8). The isolation sleeve (42) is mainly used to enhance the explosion-proof safety. The two short firing pins (21) ensure the correctness of the ball rotor's firing in the direction of rotation, which helps to obtain a longer delay in releasing the explosion-proof distance. The ball seat (3) has radial pressure relief holes and axial pressure relief channels on the ring side, which helps to release the high temperature and high pressure gas generated by the accidental firing of the needle detonator (39) in the detonation sequence (13), thereby ensuring the explosion-proof safety.

2. The rifled projectile base electromechanical detonator with self-destruct and backup trigger functions as described in claim 1, characterized in that: The electromechanical fuse power generation and ignition control part includes a body (2), a cover (5), a power generation component (9), a power connection component (10), an electric trigger component (11), a detection and ignition control electronic component (12), an electric ignition tube (35), and an electric ignition tube seat (36); the annular groove of the body (2) has ten axial holes distributed along the axial direction, starting from the twelve o'clock position and proceeding clockwise as the first threaded hole, the second stepped through hole, the third stepped hole, the fourth threaded hole, the sixth threaded hole, the seventh threaded hole, and the seventh threaded hole. Stepped hole, eighth stepped through hole, ninth threaded hole and tenth threaded hole; power generation component (9) is set in the seventh stepped hole of the body (2); there are two power connection components (10), which are respectively set in the second stepped through hole and the eighth stepped through hole of the body (2); electric trigger component (11) is set in the third stepped hole of the body (2); detection and ignition control electronic component (12) is set on the left side of the annular groove of the body (2), and is connected to the first threaded hole on the body (2) by two bolts (38). The ninth threaded hole is used for fixing; after the power generation component (9), the power connection component (10), the electric trigger component (11) and the detection and ignition control electronic component (12) are installed in the body (2), they are all encapsulated with potting compound (37) and connected and fixed to the fourth threaded hole, the sixth threaded hole and the tenth threaded hole on the body (2) by the pressure cap (5) through three screws (41); the motor weight (23) in the power generation component (9) is pushed by the recoil force to make the magnetic core of the recoil generator move downward. The detection and ignition control electronic component (12) can be set by the weapon system's setter before launch by the power receiving component (10) below the fuse to the number of projectile revolutions corresponding to the predetermined airburst distance and the self-destruct time that meets tactical requirements. After launch, the projectile revolutions are counted and the distance is fixed for airburst by detecting the geomagnetic signal, or the self-destruction or extinguishing is achieved after the predetermined self-destruct time, or the triggering component (11) is used to trigger the ignition, and the self-discharge, i.e., the energy dissipation of the electric ignition, is achieved after the fuse misfires.

3. The rifled projectile base electromechanical detonation fuse with self-destruct and backup trigger functions according to claim 2, characterized in that: The electric ignition tube (35) is ignited by the detection and ignition control electronic component (12) under the control of the distance airburst, electric trigger, or timed self-destruct signal. It directly detonates the needle detonator (39). The needle detonator (39) then detonates the detonating charge (22) in the upright isolation ball (20), which in turn detonates the detonating tube (40). If the isolation ball (20) fails to be upright and thus fails to release the explosion barrier, the needle detonator (39) will be detonated but the detonating charge (22) will not be detonated. This will lead to the explosion barrier being destroyed. Fire; if the fixed-distance air-to-ground bomb's rotation speed and self-destruct time are not set before launch, or if the detection and ignition control electronic components (12) fail to properly control the electric ignition tube (35) to detonate, then when the bomb's rotation speed decreases to the point where the centrifugal inertial force of the centrifugal ball (18) along the self-destruct slope of the ball seat (3) is insufficient to support and balance the resistance of the inertial spring (19) in the recoil safety mechanism (7), the inertial spring (19) will push the firing body (17) in the recoil safety mechanism (7) axially. The forward movement causes the needle detonator (39) mounted above the firing body (17) to strike the short firing pin (21) below the isolation ball (20), which has been turned positive by centrifugal inertial force, and ignite it, thus achieving centrifugal self-destruction of the fuse. After the fuse is released from isolation, before the count-time airburst, electronic timing self-destruction, and centrifugal self-destruction occur, if the projectile hits the target at a small or large angle of impact, the inertial trigger switch (34) in the electric trigger assembly (11) will be closed by the forward force to connect the circuit, causing the fuse to ignite. The fuse is triggered by electrical impulse. If the projectile has hit the target or target area, the firing body (17) will carry the centrifugal ball (18) and the needle detonator (39) along with the inertial spring (19) to overcome the constraint reaction force generated by the centrifugal ball (18) along the self-destructing ramp and rush forward together. This causes the needle detonator (39) installed on the firing body (17) to hit the short firing pin (21) below the isolation ball (20) which has been turned positive by centrifugal inertial force and ignite. The fuse realizes the backup inertial triggering function.

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