A fuze elastic recoil safety mechanism with double side damping

Abstract

The application discloses a fuze elastic recoil safety mechanism with double-side damping, which comprises a fuze body, an inertia cylinder, an inertia spring, a bottom cover, an upper cover, a safety-protected part, two damping springs, two side covers and two damping pins. The two damping pins, the damping springs and the side covers are arranged on the two sides of the inertia cylinder, so that the damping pins press the inertia cylinder and form damping delay effect on the inertia cylinder. The symmetric arrangement of the damping pins makes the total friction force on the inertia cylinder not be affected by the falling direction, and the damping pins are of light structure, so that the falling impact has little influence on the damping delay effect of the damping pins. Compared with the traditional elastic recoil safety mechanism without damping, the application has higher safety, and the safety can be ensured even if the fuze is accidentally tilted and falls in any direction. The safety mechanism has simple and compact structure, does not increase the axial space, and has obvious effect on improving the safety.

Description

Technical Field

[0001] The invention belongs to fuze safety technology, and in particular relates to a fuze elastic recoil safety mechanism with double-side damping. Background Art

[0002] Traditional fuze recoil safety mechanisms include single-degree-of-freedom and dual-degree-of-freedom mechanisms. Both mechanisms incorporate an inertia spring and an inertia cylinder. The inertia cylinder is held in the safety position by the preload resistance of the inertia spring, restricting the movement of the protected component (such as an explosion-proof element) and thus securing it. During the service handling phase, the inertia spring's resistance counteracts the arming motion of the inertia cylinder caused by credible shock conditions, ensuring that the cylinder does not accidentally arm under credible service handling shock conditions. During the launch phase, the launch overload exerts work on the inertia cylinder, causing it to recoil, overcoming the spring's resistance, until the safety is released. The inertia spring's resistance should ensure that the cylinder can reliably arm under normal launch overloads. The design of the inertia spring's resistance and the inertia cylinder's mass parameters must ensure both reliable arming of the safety mechanism during launch and safety under credible shock conditions during the service handling phase. In order to resolve the contradiction between the safety of the safety mechanism and the reliability of the safety release, the safety release stroke can be increased for optimization, or the single-degree-of-freedom elastic recoil safety mechanism can be changed to a double-degree-of-freedom recoil safety mechanism or a three-degree-of-freedom recoil safety mechanism with better vibration reduction performance. However, both methods will lead to an increase in the axial size of the safety mechanism, that is, an increase in the axial space occupied by the fuze and projectile, and at the same time increase the difficulty of processing and assembling the safety spring. Therefore, it is necessary to explore the optimization design of the recoil safety mechanism.

[0003] Regarding the friction damping effect of the side pressure pin on the secured part, the document "The Influence of Friction on the Release Characteristics of the Fuze Recoil Safety Part" (see "Acta Armamentarii" Vol. 44, No. 5, 2023, pp. 1296-1309) conducted a detailed study. The results show that the friction damping effect of the side pressure pin on the secured part can effectively improve the safety of the elastic recoil safety mechanism, but no technical solution was provided to the problem of weakening the friction damping effect of the side pressure pin under inclined falling conditions. Summary of the Invention

[0004] The purpose of the present invention is to provide a fuze elastic recoil safety mechanism with double-sided damping, which utilizes the friction damping hysteresis effect of the double-sided damping pins to improve the safety of the single-degree-of-freedom elastic recoil safety mechanism without increasing the axial space occupied.

[0005] The technical solution to achieve the objectives of the present invention is a fuze elastic recoil safety mechanism with dual-side damping, comprising a fuze body, an inertia cylinder, an inertia spring, a bottom cover, an upper cover, a secured component, two damping springs, two side covers, and two damping pins. The fuze body is provided with a transverse rectangular cross-section groove, which, together with the upper cover, forms a movement chamber for the secured component, such as a flameproof slider, which is disposed within this chamber with a clearance fit. The fuze body is axially provided with a first and second stepped hole. From bottom to top, the holes comprise a coaxial first and second step hole. The diameter of the first step hole is larger than that of the second step hole. The second step hole communicates with the aforementioned rectangular cross-section groove. The bottom cover and inertia cylinder are disposed within the first and second step holes of the fuze body. The inertia cylinder and the second step hole are clearance-fitted. An inertia spring is preloaded between the inertia cylinder and the bottom cover. Together with the fuze body, the three components form an elastic recoil safety mechanism. The preload resistance of the inertia spring causes the inertia cylinder to partially extend into the rectangular cross-section groove of the fuze body, restricting the sliding of a protected component, such as a flameproof slider, within its chamber, thereby protecting the protected component, such as the flameproof slider. Two second and second stepped holes are transversely provided on the fuze body, comprising a third and fourth step hole, respectively, coaxially disposed from inside to outside. The diameter of the fourth step hole is larger than that of the third step hole. The two second-step stepped holes in the fuze body are located on either side of the first-step stepped hole and are symmetrically arranged about the first-step stepped hole. Two damping pins and two side covers are respectively disposed in the third and fourth step holes of the two second-step stepped holes in the fuze body. A damping spring is preloaded between the damping pins and the side covers, forming a lateral damping mechanism. The third step hole of the second-step stepped hole in the fuze body communicates with the second step hole of the first-step stepped hole. The diameter of the third step hole is smaller than that of the second step hole. Due to the preload of the damping spring, one end of the damping pin abuts against the side wall of the inertia cylinder disposed in the second step hole, creating a frictional damping and hysteresis effect on the inertia cylinder as it moves axially. The damping pin is a thin-walled cylindrical structure or a stepped cylindrical structure, and its material is a low-density engineering material, which can be a magnesium alloy, an aluminum alloy, a titanium alloy or a plastic. The damping pin is made as light as possible, thereby reducing the inertial impact force on the damping pin when the fuze or ammunition accidentally tilts and falls, and preventing the damping pin from moving outward and weakening or losing the damping and delaying effect on the inertia cylinder.

[0006] Compared with the prior art, the present invention has the following beneficial effects:

[0007] (1) The fuze elastic recoil safety mechanism with double lateral damping of the present invention utilizes the structure of lateral damping pins to increase the safety of the elastic recoil safety mechanism. Without increasing the occupied axial space, it can more effectively identify the service processing environment and the launch environment, and has good safety.

[0008] (2) The lateral damping mechanism in the safety mechanism is symmetrically arranged with respect to the elastic recoil safety mechanism. When the fuze / ammunition is accidentally tilted and dropped in any direction, both lateral damping mechanisms will not fail simultaneously, thus achieving high reliability.

[0009] (3) The damping pin in the safety mechanism is light in weight. When the fuze / ammunition accidentally falls in any direction, the impact of the falling impact overload is small, and the mechanism is highly reliable.

[0010] (4) The lateral damping mechanism in the safety mechanism has a simple structure, occupies a small axial space, has high reliability and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a cross-sectional view of embodiment 1 of the present invention in an assembled state.

[0012] Figure 2 The response-time curves of the inertia cylinder of the present invention under the action of launch overload obtained by simulation, wherein (a) is the displacement response-time curve of the inertia cylinder, and (b) is the velocity response-time curve of the inertia cylinder.

[0013] Figure 3 The response-time curves of the inertia cylinder of the present invention under the action of drop overload obtained by simulation, wherein (a) is the displacement response-time curve of the inertia cylinder, and (b) is the velocity response-time curve of the inertia cylinder.

[0014] Figure 1 In the middle: 1 is the bottom cover, 2 is the fuse body, 3 is the damping spring, 4 is the side cover, 5 is the damping pin, 6 is the inertia cylinder, 7 is the inertia spring, 8 is the upper cover, and 9 is the insured part (here, the explosion-proof slider). DETAILED DESCRIPTION

[0015] The present invention will be described in further detail below with reference to the accompanying drawings.

[0016] Combine Figure 1The present invention discloses a fuze elastic recoil safety mechanism with double-sided damping, comprising a bottom cover 1, a fuze body 2, an inertia cylinder 6, an inertia spring 7, an upper cover 8, a protected component 9 (such as an explosion-proof slider), two damping springs 3, two side covers 4, and two damping pins 5. The fuze body 2 is axially provided with a first and second stepped hole, comprising a coaxially arranged first and second step hole from bottom to top, with the first step hole having a larger diameter than the second step hole. The bottom cover 1 is a circular thin sheet structure, riveted and fixed within the first step hole of the fuze body 2. The inertia cylinder 6 is a thin-walled cylindrical structure with one end open, its open end facing downward, and is loosely fitted within the second step hole of the fuze body 2. The inertia spring 7 is preloaded between the bottom cover 1 and the inertia cylinder 6, with one end extending into the inner cavity of the inertia cylinder 6 and resting against its inner end face, causing one end of the inertia cylinder 6 to rest against the inner end face of the second step hole of the fuze body 2. A rectangular cross-sectional groove is provided in the transverse direction at the upper end of the fuze body 2, and the rectangular cross-sectional groove is provided perpendicular to the axis direction of the first and second step stepped holes, and the secured part 9 is provided in the rectangular cross-sectional groove with a clearance fit. The upper cover 8 is provided at the upper end of the fuze body 2, and together with the rectangular cross-sectional groove on the fuze body 2, constitutes a movement chamber for the secured part 9, and the secured part 9 can slide transversely in the movement chamber. The rectangular cross-sectional groove on the fuze body 2 is connected to the second step hole of its first and second step stepped holes, so that the upper end portion of the inertia cylinder 6 extends into the rectangular cross-sectional groove, thereby limiting the secured part 9 from sliding transversely along the rectangular cross-sectional groove. The fuze body 2, the inertia cylinder 6, the inertia spring 7 and the bottom cover 1 together constitute an elastic recoil safety mechanism for realizing a safety for the secured part 9. The fuze body 2 is laterally provided with two second-step stepped holes. These holes each include a third-step hole communicating with the second-step hole and a fourth-step hole coaxially disposed on the outside of the second-step hole. The diameter of the third-step hole is smaller than that of the second-step hole, while the diameter of the fourth-step hole is larger than that of the third-step hole. The side cover 4 is a circular thin sheet riveted into the fourth-step hole of the fuze body 2. The damping pin 5 is loosely fitted within the third-step hole of the fuze body 2, with one end resting against the side wall of the inertia cylinder 6. The damping spring 3 is preloaded between the side cover 4 and the damping pin 5, causing the damping pin 5 to preload the inertia cylinder 6, thereby ensuring that the damping pin 5 provides frictional damping and retardation during axial movement of the inertia cylinder 6.

[0017] Furthermore, the two second-stage stepped holes on the fuze body 2 are symmetrically arranged with respect to the first-stage stepped hole, thereby ensuring that when the fuze / ammunition is accidentally dropped at any tilted orientation, the two symmetrically arranged damping pins 5 will not simultaneously lose contact with the inertia cylinder 6 and lose the frictional damping delay effect on the inertia cylinder 6.

[0018] Furthermore, the damping pin 5 is a thin-walled cylindrical structure, with one end of the damping spring 3 extending into its inner cavity and resting against its inner end surface. The damping pin 5 is made of a low-density engineering material, such as a magnesium alloy, aluminum alloy, titanium alloy, or plastic, to minimize its weight. This reduces the inertial impact force exerted on the damping pin 5 when the fuze / ammunition accidentally tilts and falls, and prevents the damping pin 5 from moving outward and weakening or losing its damping and delaying effect on the inertia cylinder 6.

[0019] A set of design parameters for a fuze elastic recoil safety mechanism with double-sided damping is listed in Table 1. The displacement response-time curve and velocity response-time curve of the inertia tube under different friction conditions under launch overload are obtained by computer numerical simulation. Figure 2 As shown in the figure, the displacement response-time curve and velocity response-time curve of the inertial cylinder under the action of drop overload are as follows: Figure 3 As shown, Figure 2 and Figure 3 The μ in is the sliding friction coefficient μ between the damping pin 5 and the inertia cylinder 6. The state of μ=0 is equivalent to a common recoil safety mechanism without lateral damping. Figure 2 and Figure 3 It can be seen that the friction damping hysteresis effect of the side pressure pin under different friction conditions has little effect on the reliability of the safety mechanism under launch overload, but has a significant impact on the safety of the safety mechanism under drop overload.

[0020] Table 1 Design parameters of a fuze elastic recoil safety mechanism with double-sided damping

[0021]

[0022] Computer numerical simulations revealed the arming time and maximum displacement response of the inertia cylinder under launch and drop overload conditions under varying lateral pressure and friction forces, as shown in Table 2. Table 2 shows that when the friction force of the damping pin on the inertia cylinder is within the range of 0 to 3.20 N, the safety mechanism reliably arming under launch overload is achieved. However, when the friction force of the damping pin on the inertia cylinder is greater than or equal to 2.56 N, safety is guaranteed under drop overload conditions. However, when the friction force is less than 2.56 N, safety cannot be guaranteed under drop overload conditions.

[0023] Table 2 Release time of the safety mechanism and maximum displacement response of the inertia cylinder under different lateral pressure friction forces

[0024]

[0025] The working process of a fuze elastic recoil safety mechanism with double-sided damping is as follows:

[0026] Normally, the inertia cylinder 6 within the fuze body 2, under the preload resistance of the inertia spring 5, has one end partially extended into the movement chamber of the secured component 9, preventing it from sliding within its movement chamber. This provides a safety barrier for the secured component 9, maintaining its explosion-proof state. The damping pins 5 in the two symmetrically arranged lateral damping mechanisms, under the preload resistance of the damping spring 3, have their ends resting against the sidewalls of the inertia cylinder 6.

[0027] During the service handling stage, when the fuze or projectile bottom falls vertically downward accidentally, the inertia cylinder 6 moves axially downward under the action of the falling impact, and the inertia spring 7 is gradually compressed while its resistance hinders the downward movement of the inertia cylinder 6; at the same time, the damping pins 5 symmetrically arranged on both sides of the inertia cylinder 6 always rest against the side walls of the inertia cylinder 6, forming a positive pressure and a friction force between the inertia cylinder 6 and the inertia cylinder 6, further hindering the downward movement of the inertia cylinder 6; when falling vertically downward, the direction of the falling impact overload is perpendicular to the movement direction of the damping pin 5, and will not change the positive pressure and friction force of the damping pin 5 on the inertia cylinder 6; during the downward movement of the inertia cylinder 6, its potential energy is gradually converted into the elastic potential energy of the inertia spring 7 and the heat energy generated by the friction with the damping pin 5. Finally, the inertia cylinder 6 stops moving downward and cannot reach the safety release position (distance). After the falling impact disappears, the inertia cylinder 6 will overcome the friction force generated by the damping spring 3 through the damping pin 5 under the action of the resistance of the inertia spring 7 and return to its initial position. The elastic recoil safety mechanism can ensure the safety of the fuze during the service handling stage.

[0028] During the service handling stage, when the fuze or projectile falls at an angle in any direction, the inertia cylinder 6 moves axially downward under the action of the falling impact, and the inertia spring 7 is gradually compressed while its resistance hinders the downward movement of the inertia cylinder 6; at the same time, under the action of the falling impact overload, the positive extrusion pressure of one of the two damping pins 5 symmetrically arranged on both sides of the inertia cylinder 6 on the inertia cylinder 6 increases due to the falling impact, while the positive extrusion pressure of the other damping pin 5 on the inertia cylinder 6 decreases due to the falling impact. Since the two sets of damping pins 5, the damping spring 3 and the second-step stepped holes on the fuze body 2 are exactly the same and symmetrically arranged, the reduction in the extrusion pressure of one damping pin 5 is always equal to that of the other damping pin 5, thereby ensuring that the sum of the squeezing forces of the two damping pins 5 on the inertia cylinder 6 remains unchanged, that is, the total friction force of the two damping pins 5 on the inertia cylinder 6 does not change, and the friction damping delay effect of the two damping pins 5 on the inertia cylinder 6 will not be weakened due to tilting and falling. The inertia cylinder 6 will stop moving downward under the resistance of the inertia spring 7 and the friction of the damping pins 5 and will not be able to reach the safety release position (distance). After the falling impact disappears, the inertia cylinder 6 will overcome the friction force generated by the damping spring 3 through the damping pins 5 under the resistance of the inertia spring 7 and return to its original position, thereby ensuring the safety of the elastic recoil safety mechanism when it is tilted and fallen in any direction during the service processing stage.

[0029] When the projectile is launched, the inertia cylinder 6 moves axially downward under the action of the launch overload, and the inertia spring 7 is gradually compressed, and its resistance hinders the downward movement of the inertia cylinder 6; at the same time, the damping pins 5 symmetrically arranged on both sides of the inertia cylinder 6 always press against the side walls of the inertia cylinder 6, forming a positive pressure and friction force on the inertia cylinder 6, forming a damping and delaying effect on the downward movement of the inertia cylinder 6. The direction of the launch overload is perpendicular to the movement direction of the damping pin 5, and will not change the positive pressure and friction force of the damping pin 5 on the inertia cylinder 6. Part of the work done on the inertia cylinder 6 by the launch overload is converted into the elastic potential energy of the inertia spring 7 and the heat energy generated by the friction with the damping pin 5. However, because the launch overload lasts for a long time and continues to do work on the inertia cylinder 6, the resistance of the inertia spring 7 and the friction of the damping pin 5 do not affect the inertia cylinder 6 from releasing the safety of the secured part 9, that is, do not affect the reliability of the fuze arming safety. Finally, under the action of the launch overload, the inertia cylinder 6 continues to move downward until the top end of the inertia cylinder 6 completely disengages from the rectangular cross-section groove on the fuze body 2. The inertia cylinder 6 will no longer restrict the sliding of the secured part 9 along its moving chamber, that is, the recoil safety of the secured part 9 is released.

[0030] The damping pin structure in this elastic recoil safety mechanism effectively improves the safety mechanism's safety without increasing axial space, while still ensuring reliable arming. The lateral damping pins are symmetrically arranged about the inertia cylinder and are designed as lightweight components, effectively minimizing the impact of tilted drop shock on the friction damping hysteresis effect. This elastic recoil safety mechanism has a simple overall structure, does not occupy additional axial space, and is easy to implement and cost-effective.

Claims

1. A fuze elastic recoil safety mechanism with double-sided damping, comprising a bottom cover (1), a fuze body (2), an inertia cylinder (6), an inertia spring (7), a safety member (9), two damping springs (3), two side covers (4) and two damping pins (5); wherein the fuze body (2) is provided with a two-step stepped hole along the axial direction, comprising a first-step hole and a second-step hole coaxially arranged from bottom to top; the bottom cover (1) and the inertia cylinder (6) are respectively provided on the fuze body (2) In the first step hole and the second step hole, the inertia cylinder (6) and the second step hole on the fuze body (2) are clearance-fitted, and the inertia spring (7) is pre-stressed between the inertia cylinder (6) and the bottom cover (1) and together constitutes a fuze elastic recoil safety mechanism; a movement chamber of the insured part is provided on the fuze body (2), and the insured part (9) is clearance-fittedly arranged in the movement chamber, and the second step hole on the fuze body (2) is communicated with the movement chamber, and part of the inertia cylinder (6) extends into the movement chamber to limit the movement of the insured part (9), thereby achieving the insurance of the insured part (9); two transverse second step holes are provided on both sides of the second step hole of the axial second step hole on the fuze body (2), and the two transverse second step holes include a coaxially arranged third step hole and a fourth step hole in sequence from the inside to the outside, and the third step hole on the fuze body (2) is communicated with the second step hole, and the diameter of the second step hole is larger than the diameter of the third step hole; the damping pin (5) and the side cover (4) are respectively provided on the fuze body (2) and the second step hole. In the third-step hole and the fourth-step hole on the fuse body (2), the damping pin (5) and the third-step hole on the fuse body (2) are clearance-fitted, and the damping spring (3) is pre-pressed between the damping pin (5) and the side cover (4), and together with the damping spring (3), a lateral damping mechanism is formed; under the action of the damping spring (3), one end of the damping pin (5) in the two sets of lateral damping mechanisms abuts against the side wall of the inertia cylinder (6), and a friction damping delay effect is formed on the inertia cylinder (6) when the inertia cylinder (6) moves in the axial direction; In the assembled state, the two transverse second-step stepped holes on the fuze body (2) are symmetrically arranged on both sides of the axial second-step stepped hole, that is, the two sets of lateral damping mechanisms consisting of the damping pin (5), the damping spring (3) and the side cover (4) are symmetrically arranged about the second-step hole on the fuze body (2).

2. A fuze elastic recoil safety mechanism with double-sided damping according to claim 1, characterized in that: The damping pin (5) is a thin-walled cylindrical structure or a stepped cylindrical structure, and its material is a low-density engineering material, so that the damping pin (5) is as light as possible, thereby reducing the inertial impact force on the damping pin (5) when the fuze or ammunition accidentally tilts and falls, and preventing the damping pin (5) from moving outward and weakening or losing the damping delay effect on the inertia cylinder (6).

3. The fuze elastic recoil safety mechanism with double-sided damping according to claim 2, characterized in that: The damping pin (5) is made of magnesium alloy, aluminum alloy, titanium alloy or plastic.

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