A fuze arming mechanism which is armed and disarmed by a permanent magnet key

Abstract

This invention discloses a fuse safety mechanism that utilizes a permanent magnet key for disarming. The mechanism includes a body, a safety element, a safety spring, a retainer, and a protected component. A release mechanism is also attached outside the fuse. The safety element and the release mechanism's inner liner are made of permanent magnets. A pre-compressed safety spring is located between the retainer and the safety element. Under the combined action of their magnetic force and the resistance of the safety spring, the two safety elements pass through a pre-drilled hole in the body and make direct contact, thus securing the protected component. To disarm, the release mechanism is placed on the outer wall of the fuse, with its inner liner facing the outer end of the fuse's safety element and their adjacent ends having opposite polarities. The safety element, attracted by the magnetic force of its inner liner, overcomes the magnetic attraction of the other safety element and compresses the safety spring, moving outward to disarm the protected component. After the release mechanism completes the disarming operation and removes the fuse, the safety element resets under the resistance of the safety spring and the magnetic attraction of the other safety element, its end extending into the protected component for reverse reset. This invention is primarily applicable to non-rotating spring fuses, especially those requiring manual disarming.

Description

Technical Field

[0001] This invention belongs to the field of fuse security technology, specifically relating to a fuse insurance mechanism that uses a permanent magnet key to disarm the fuse. Background Technology

[0002] To ensure safety, both GJB373B-2019 and MIL-STD-1316F standards, "Design Guidelines for Fuze Safety," specify redundancy safety design requirements. For some non-rotating projectile mechanical fuses, a manually disengaged transport safety pin structure is often used as a first safety mechanism. For example, the Soviet M-6 fuse (see page 74 of "Fuse Construction and Function," edited by Ma Baohua). Figure 5-3 (National Defense Industry Press, 1st edition, December 1984); American M52A1 fuze (see page 80 of "Fuse Construction and Function" edited by Ma Baohua). Figure 5-7 (National Defense Industry Press, 1st edition, December 1984) and the vast majority of grenade fuses.

[0003] The transport safety pin structure is difficult to seal, which may significantly shorten the product's shelf life. This difficulty in sealing allows foreign objects to easily enter the mechanism, affecting reliability. Furthermore, the transport safety pin structure is exposed on the fuse's outer surface, and its irregular shape may interfere with soldiers' tactical movements or even lead to accidental disengagement when used in small arms fuses. Manually pulling out the transport safety pin may also affect the correctness of the secured component, negatively impacting the reliability of disengagement and making it difficult to guarantee. Summary of the Invention

[0004] The purpose of this invention is to provide a fuse safety mechanism that uses a permanent magnet key to disarm the fuse. It occupies less space, is highly modular and versatile, and is suitable for fuses of non-rotating projectiles such as mortar shells, hand grenades, rifle grenades and man-portable rockets, especially as a second safety mechanism that allows manual disarming.

[0005] The technical solution for achieving the purpose of this invention is as follows: A fuse safety mechanism that uses a permanent magnet key to disarm the fuse includes a body, a disarming device, and a pair of safety sub-mechanisms. Each safety sub-mechanism includes a safety element, a safety spring, and a stop plate. A pair of symmetrical inner liners are inlaid inside the disarming device. Both the inner liners and the safety element are made of permanent magnets. The insecured element includes a slide and a second detonating tube. A first detonating tube is provided inside the fuse. The body is a rotating body, with a first stepped hole opening upwards along the axis at the bottom end, followed by a first-step hole, a second-step hole, and a third-step hole from bottom to top. Two radially symmetrical second-step holes are provided on the side wall, connecting to each other. From the outside in, these second-step holes are sequentially arranged as fourth, fifth, and sixth-step holes. The first detonating cord is riveted and fixed within the third-step hole, and the second detonating cord is riveted and fixed within the slide, which is located within the second-step hole. The safety element is a second-step cylinder with a smaller inner diameter. A baffle is riveted and fixed within the fourth-step hole, and a pre-compressed safety spring is located between the safety element and the baffle. Under the mutual magnetic attraction and the resistance of the safety spring, the inner ends of the two safety elements pass through the sixth-step hole and extend into the second-step hole, making direct contact and thus securing the insured element. When the safety needs to be released, place the release device on the outer wall of the fuse, ensuring that its inner liner faces the outer end of the fuse safety element with opposite polarities at adjacent ends. The safety element, attracted by the magnetic force of its inner liner, overcomes the magnetic force of the other safety element and compresses the safety spring, moving outward to release the safety on the insured component. After the release device completes the release operation and is removed from the fuse, the safety element will reset under the resistance of the safety spring and the magnetic force of the other safety element, its inner end extending into the reset hole on the insured component to achieve reset.

[0006] The inner wall shape of the release device matches the outer wall shape of the fuse, and the asymmetrical shape design ensures that the polarity of the inner liner on the release device matches the polarity of the fuse safety element, so as to complete the release action conveniently, quickly and reliably.

[0007] Compared with the prior art, the significant advantages of this invention are:

[0008] (1) The structure is easy to seal, has high reliability, and long storage life.

[0009] (2) The safety cannot be disarmed by hand, which is highly safe, facilitates the security management of ammunition, and can also prevent it from being used by the enemy.

[0010] (3) It has weak structural correlation with other institutions, making it easy to apply.

[0011] (4) It may be applicable to both rotating and non-rotating environments. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view along the axis of a fuse safety mechanism that uses a permanent magnet key to disarm the fuse according to the present invention.

[0013] Figure 2 This is a sectional view (front view) along the axis of the fuse release device for the fuse release mechanism of the present invention, which uses a permanent magnet key to release the fuse.

[0014] Figure 3 This is another cross-sectional view (left view) along the axis of the fuse insurance mechanism matching the present invention, which uses a permanent magnet key to release the fuse insurance.

[0015] Figure 4 This is another cross-sectional view (right view) along the axis of the fuse release device for the fuse release mechanism of the present invention, which uses a permanent magnet key to release the fuse.

[0016] Figure 5 This is a bottom view of a fuse release device for a fuse insurance mechanism that uses a permanent magnet key to release the fuse according to the present invention.

[0017] Figure 6 This is a cross-sectional view (AA) of a fuse release device for releasing the fuse using a permanent magnet key, according to the present invention.

[0018] Figure 7 This is an isometric drawing of a fuse release device for a fuse release mechanism that utilizes a permanent magnet key to release the fuse according to the present invention.

[0019] Figure 8 This is an isometric drawing of a fuse belonging to a fuse insurance mechanism that uses a permanent magnet key to disarm the fuse according to the present invention.

[0020] In the diagram, 1 is the main body, 2 is the first detonating cord, 3 is the safety element, 4 is the safety spring, 5 is the baffle, 6 is the slide, 7 is the second detonating cord, 8 is the push spring, 9 is the retaining ring, 10 is the reinforcing cap, 11 is the detonating charge, 12 is the detonating tube shell, 13 is the release device, and 14 is the inner lining. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings.

[0022] Combination Figure 1 and Figure 8The present invention discloses a fuse safety mechanism that uses a permanent magnet key to disarm the fuse, comprising a body 1, a disarm 13, and a pair of safety sub-mechanisms. Each safety sub-mechanism includes a safety element 3, a safety spring 4, and a baffle 5. A pair of symmetrical inner liners 14 are inlaid inside the disarm 13. Both the inner liners 14 and the safety element 3 are made of permanent magnets. The insecured element includes a slide 6 and a second detonating tube 7. A first detonating tube 2 is provided inside the fuse. The body 1 is a rotating body, and a first detonating tube is opened upwards along the axis at the bottom end of the body 1. The stepped holes, from bottom to top, are the first-step hole, the second-step hole, and the third-step hole; two second-step holes are radially symmetrically arranged on the outer wall of the body 1, and the second-step holes connect to the second-step holes. The second-step holes, from the outside to the inside, are the fourth-step hole, the fifth-step hole, and the sixth-step hole; the first detonating cord 2 is riveted and fixed in the third-step hole, and the second detonating cord 7 is riveted and fixed in the slide 6, with the slide 6 located in the second-step hole; the safety element 3 is a second-step cylinder with a small inner diameter, and the inner end extends into the second... The fourth-stage hole is fixed with the baffle 5 riveted in, and the pre-compressed safety spring 4 is located between the safety element 3 and the baffle 5. Under the mutual magnetic attraction and the resistance of the safety spring 4, the ends of the two symmetrically arranged safety elements 3 pass through the sixth-stage hole and extend into the second-stage hole and make positive contact, blocking the detonation channel between the first detonating tube 2 and the second detonating tube 7, thus securing the second detonating tube 7 in the slide block 6. When it is necessary to release the safety, the release device 13 is placed on the outer wall of the fuse, so that its inner lining 14 Facing the outer end of the fuse safety element 3, with adjacent ends having opposite polarities, the safety element 3, under the magnetic attraction of the inner liner 14, overcomes the magnetic attraction of the other safety element 3 and further compresses the safety spring 4, moving outward to release the safety on the slide 6 and the second detonating tube 7 in the insured component, thus opening the detonation channel between the first detonating tube 2 and the second detonating tube 7. The slide 6, together with the second detonating tube 7 inside it, moves upward into place under the action of the push spring 8, that is, the upper end face of the slide 6 abuts against the bottom of the second-stage hole. After the release device 13 completes the release operation and removes the fuse, the safety element 3 will reset under the action of its magnetic force and the resistance of the safety spring 4, and its inner end will extend into the anti-reset hole on the insured component to achieve anti-reset.

[0023] Furthermore, the diameter of the recovery hole on the slide 6 is larger than the diameter of the inner end of the safety element 3, ensuring that the inner end of the safety element 3 can still be inserted into the safety element after the safety element moves.

[0024] Furthermore, the design of the slide block 6, the shell of the second detonating tube 7, and the explosive charge inside them is symmetrical about the axis, and their dimensional accuracy is controlled within IT11 level to ensure that the average position of their center of gravity is on their axis, thereby preventing inertial interference forces from causing the radial recovery hole on the slide block 6 to deviate significantly from the inner end of the safety element 3 and thus affecting the intended recovery function.

[0025] Furthermore, two asymmetrical positioning grooves are provided along the axial direction at the opening of the second stepped hole on the outer wall of the main body 1 to achieve orientation and positioning of the release device 13, ensuring that the polarity of the inner liner 14 on the release device 13 is opposite to the polarity of the safety element in the fuse safety mechanism.

[0026] Furthermore, on the outer wall near the two second-step holes on the main body 1, along the axial direction, the interface shape of the positioning grooves provided by the release device 13 on the main body 1 is a plane and the other is an arc surface.

[0027] Furthermore, neodymium iron boron (NdFeB) is selected as the permanent magnet material. NdFeB permanent magnets possess excellent magnetic properties, are lightweight and inexpensive, and are hard, making them the most cost-effective magnet material to date. However, NdFeB permanent magnets have poor temperature performance and are prone to corrosion after sintering, requiring plating treatment to ensure long-term storage life.

[0028] Furthermore, adjacent structural components such as body 1, baffle 5, slide 6, first detonating tube housing and second detonating tube housing are made of non-magnetic materials.

[0029] Furthermore, non-magnetic materials such as aluminum alloys, plastics, copper alloys, and martensitic stainless steel are also included.

[0030] Furthermore, the cross-section of the lining 14 is arc-shaped.

[0031] Furthermore, the input end structure of the detonator is concave in the center to allow space in the central area for the fuze mechanism, thereby reducing or saving axial space occupied by the fuze.

[0032] This invention is applicable to fuses for non-spinning projectiles such as mortar shells, hand grenades, rifle grenades, and man-portable rockets, particularly their second safety mechanism that is manually disarmed. This invention has weaker interrelationships with other mechanisms, making it easy to apply.

[0033] The main safety principle of the fuse safety mechanism of this invention, which utilizes a permanent magnet key to disarm the fuse, is as follows:

[0034] During service, the fuse is in its factory-assembled state. The two safety components 3, under the combined force of their magnetic attraction and the resistance of the pre-compressed safety spring 4, make direct contact, blocking the detonation transmission channel between the first detonating tube 2 and the second detonating tube 7, thus securing the second detonating tube 7 in the slide 6. Since the input end of the second detonating tube 7 is in close contact with the output end of the first detonating tube 2 in the disarmed state, from the perspective of detonation transmission reliability, the first detonating tube 2 does not need to have a very high explosive power, which also benefits the explosion-proof safety design of the safety component 3. In the assembled state, even if the first detonating tube 2 accidentally explodes, it will not detonate the second detonating tube 7 in the slide 6, nor the explosive charge 11 behind it, thus achieving explosion-proof safety for the fuse. During this stage, even if the fuse is subjected to reliable impacts or vibrations, including accidental drops and transport vibrations, the two safety components 3 will not separate, thus preventing the detonation channel between the first detonating tube 2 and the second detonating tube 7 from opening up. Furthermore, the safety component will not release, causing the second detonating tube 7 to move upwards and approach the first detonating tube 2. Therefore, the fuse will not accidentally disengage or detonate. No manual operation can separate the two safety components 3, thus preventing the detonation channel between the first detonating tube 2 and the second detonating tube 7 from opening up, and therefore, the fuse will not accidentally disengage. Because the two safety components 3 are symmetrically arranged, each safety component 3 can prevent the slide 6 and the second detonating tube 7 in the safety component from shifting upwards, and the movement of each safety component 3 is reversible. Therefore, under operational handling and a predetermined non-rotational firing environment, the non-dedicated safety release device 13 will not accidentally disengage the fuse. These characteristics improve fuse safety, facilitate ammunition security management, and prevent misuse by the enemy. This is especially significant for hand grenade fuses where disengagement is entirely manual.

[0035] Before firing or throwing the ammunition, the safety release device 13 is fitted onto the outer wall of the fuse, with its inner liner 14 facing the outer end of the fuse safety element 3. Utilizing the principle of opposite poles attracting, its magnetic attraction overcomes the resistance of the safety spring 4 and the magnetic attraction of the other safety element 3, pulling the safety element 3 outward. The safety element 3 moves radially outward, releasing the safety on the slide 6 and the second detonating tube 7 of the protected component. Under the action of the push spring 8, the slide 6 and the second detonating tube 7 move upward relative to the body 1, stopping when the slide 6 reaches its highest point against the step surface between the second and third stage holes. The slide 6 has a radial recovery hole. After the safety release device 13 completes the safety release operation and removes the fuse, the safety element 3, under the resistance of the safety spring 4 and its magnetic attraction, moves inward and inserts into the radial recovery hole on the slide 6, putting the fuse in the released state. This state will be maintained throughout the subsequent firing process.

[0036] When the ammunition hits the target or target area, the fuse ignition mechanism activates, and the detonation sequence detonates the first detonating tube 2. The first detonating tube 2 then detonates the second detonating tube 7, which in turn detonates the detonating charge 11 in the detonating tube, thus completing the detonation output.

[0037] The ignition mechanism of the fuse, the explosion-proof mechanism, the delayed release mechanism, the initial explosive element and its subsequent detonation sequence, and the additional safety mechanism of the fuse set up to meet the redundancy safety design requirements—all of these utilize mature technologies. Figure 1 It is not shown in the middle.

[0038] The structure of this invention, when applied to a fuze with only one recoil safety mechanism, can achieve redundant safety. When applied, it is added below the fuze's explosion-proof mechanism and above the detonation tube, without affecting the existing design of the fuze's ignition mechanism, explosion-proof mechanism, delayed release safety mechanism, etc. It is estimated that the permanent magnet safety component 3 will require an increase in axial length of 4 mm, the second detonating tube 7 will require an increase in axial length of 5 mm, and the push spring 8 will require an increase in axial length of 4 mm. Meanwhile, the first detonating tube 2 is expected to be shortened by 2 mm, and the detonation tube is expected to be shortened by 4 mm. Therefore, it can be concluded that applying the structure of this invention to the fuze requires approximately 7 mm more space.

[0039] If needed, the mechanism of this invention can be used in both rotating and non-rotating environments. In a non-rotating environment, the safety is released before launch by the release device 13; that is, the magnetic attraction provided by the release device 13 overcomes the attraction between the paired safety elements 3 and the resistance of the safety spring 4, pulling the safety elements 3 radially outward to release the safety. In a rotating environment, the safety is released during launch and flight by the centrifugal force generated by the rotating environment; that is, the centrifugal force of the safety elements 3 themselves overcomes the attraction between the paired safety elements 3 and the resistance of the safety spring 4, moving the safety radially outward to release the safety.

Claims

1. A fuse safety mechanism that uses a permanent magnet key to disarm the fuse, comprising a body (1), a disarming device (13), and a pair of safety sub-mechanisms. The safety sub-mechanisms include a safety element (3), a safety spring (4), and a baffle (5). A pair of inner liners (14) are symmetrically inlaid inside the disarming device (13). The inner liners (14) and the safety element (3) are both made of permanent magnets. The insured element includes a slide (6) and a second detonating tube (7). The fuse contains a first detonating tube (2). The body (1) is a rotating body. The bottom of the body (1) has a first stepped hole along the axis upwards, and from bottom to top, there are first stepped holes, second stepped holes and third stepped holes; the outer wall of the body (1) has two second stepped holes symmetrically arranged radially, the second stepped holes are connected to the second stepped holes, and from the outside to the inside, the second stepped holes are fourth stepped holes, fifth stepped holes and sixth stepped holes; the first detonating tube (2) is riveted and fixed in the third stepped hole, the second detonating tube (7) is riveted and fixed in the slide (6) and the slide (6) is located in the second stepped hole; the safety component ( 3) It is a second-order cylinder with a small inner diameter. The inner end extends into the second-order hole. The baffle (5) is riveted and fixed in the fourth-order hole. The pre-compressed safety spring (4) is located between the safety element (3) and the baffle (5). It is symmetrically arranged in pairs in the fifth and sixth-order holes. The two safety elements (3) have opposite magnetic poles facing each other and are pushed by the pre-compressed safety spring (4) to block the detonation channel between the first detonating tube (2) and the second detonating tube (7), thus achieving safety for the second detonating tube (7) in the slide (6). When it is necessary to release the safety, the release device (13) is placed on the outer wall of the fuse, with its inner liner (14) facing the outer end of the fuse safety element (3), and the adjacent ends of the inner liner (14) and its corresponding safety element (3) have opposite polarities. The inner liner (14) inside the release device (13) overcomes the magnetic attraction of the other safety element (3) by the principle of opposite poles attracting each other and compresses the safety spring (4) to attract the safety element (3) outward. The safety element (3) moves outward along the radial direction to release the safety of the second detonating tube (7).

2. The fuse safety mechanism for releasing the fuse using a permanent magnet key according to claim 1, characterized in that: The slide (6) is provided with a pair of radial recovery holes. After the release device (13) completes the release operation and removes the fuse, the safety element (3) is inserted into the radial recovery hole on the slide (6) under the action of the push of the safety spring (4) and the magnetic attraction of the other safety element (3). The fuse will always be in this released state during the subsequent launch or throwing process.

3. The fuse safety mechanism for releasing the fuse using a permanent magnet key according to claim 2, characterized in that: The diameter of the recovery hole on the slide (6) is larger than the diameter of the inner end of the safety element (3) to ensure that the inner end of the safety element (3) can still be inserted into the safety element after the safety element moves.

4. The fuse safety mechanism for disarming the fuse using a permanent magnet key according to claim 2, characterized in that: The tube shell of the slide (6) and the second detonating tube (7) and the explosive charge inside it are designed to be symmetrical about the axis, and their dimensional accuracy is controlled within IT11 level. This ensures that the average position of the center of mass of the insured part is on its axis, thereby preventing the inertial interference force from causing the radial recovery hole on the slide (6) to deviate significantly from the inner end of the insured part (3) and affecting the intended recovery function.

5. A fuse safety mechanism for disarming a fuse using a permanent magnet key according to claim 1, characterized in that: On the outer wall of the body (1), and at the position of the outer opening of the two second step holes, there is a positioning groove along the axial direction. However, the two positioning grooves are different in shape so as to adapt to the shape of the inner wall of the release device (13) and thus realize the orientation and positioning of the close-in action when the release device (13) releases the safety, ensuring that the polarity of the inner liner (14) in the release device (13) matches the polarity of the safety component in the fuse safety mechanism.

6. A fuse safety mechanism for disarming a fuse using a permanent magnet key according to claim 5, characterized in that: The two positioning grooves have different interface shapes on the body (1), one being a plane and the other being an arc surface.

7. A fuse safety mechanism for disarming a fuse using a permanent magnet key according to claim 1, characterized in that: The permanent magnet is made of neodymium iron boron material.

8. A fuse safety mechanism for disarming a fuse using a permanent magnet key according to claim 1, characterized in that: The shells of the main body (1), baffle (5), slide (6), first detonating tube (2), and second detonating tube (7) are made of non-magnetic materials.

9. A fuse safety mechanism for disarming a fuse using a permanent magnet key according to claim 8, characterized in that: Non-magnetic materials include aluminum alloys, plastics, copper alloys, and martensitic stainless steel.

10. A fuse safety mechanism for disarming a fuse using a permanent magnet key according to claim 1, characterized in that: The input end structure of the detonation tube in the fuze is concave in the center, which is used to give up part of the central area to the fuze mechanism, thereby reducing the space occupied by the fuze axial space.

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