A friction acceleration device with long-time sequence, high overload and stable acceleration and its control method

Abstract

The present invention belongs to the field of impact testing technology and discloses a friction acceleration device capable of long-term, high-overload, stable acceleration. The device comprises a high-pressure gas chamber and a guide tube connected to the high-pressure gas chamber. A fast-response pressure relief device is provided at one end of the high-pressure gas chamber connected to the guide tube. The end of the guide tube, remote from the fast-response pressure relief device, is provided with a friction sleeve and a friction transmission member that interlock with each other. An accelerated object is disposed at the end of the friction transmission member. During launch, if the fast-response pressure relief device breaks, high-pressure gas in the high-pressure gas chamber rushes out, pushing the friction sleeve to move. The kinetic friction generated by the relative sliding of the friction sleeve and the friction transmission member provides acceleration for the friction transmission member, which in turn propels the accelerated object to achieve stable acceleration within the guide tube. A corresponding control method is also provided. The aforementioned acceleration device and control method are capable of providing long-term, stable acceleration.

Description

Technical Field

[0001] The present invention belongs to the technical field of impact testing, and in particular relates to a friction acceleration device with long-time sequence, high overload and stable acceleration and a control method thereof. Background Art

[0002] Traditional accelerators typically directly utilize power sources (such as electromagnetic force or high-pressure gas) to accelerate objects requiring high acceleration. When an object requires ultra-high acceleration, the system typically requires the system to instantly generate enormous thrust, potentially reaching several gigawatts. Currently, with the widespread use of electric accelerators, achieving these multi-megawatt power requirements and scale is virtually impossible. For explosive shock acceleration, the high acceleration duration is only microseconds, and the gases released during this process reach temperatures of several thousand degrees Celsius, making sustained high pressure impossible and compromising the device's safety. Traditional rocket engine gas generators typically operate at pressures of only around 10 MPa. Like explosive shock acceleration, they utilize pyrotechnics, which release gases at temperatures exceeding 1000 degrees Celsius, compromising the device's safety. When using compressed air propulsion, the required sustained acceleration pressure exceeds hundreds of MPa. This is difficult to generate, and the high-pressure air power source rapidly decays after generating the explosive driving force, making the high pressure unsustainable. This results in insufficient acceleration duration and the inability to achieve stable acceleration. In the compressed air drive mode, although the use of carbon dioxide liquid-gas phase change catapult can achieve high overload loading of the target at a lower cost, it requires an ultra-high pressure initial power source and it is difficult to achieve long-term stable amplitude loading. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings and defects mentioned in the above background technology and provide a friction acceleration device and a control method thereof that can provide long-term stable acceleration and long-term high-overload stable acceleration. To solve the above technical problems, the technical solutions proposed by the present invention are as follows:

[0004] A friction acceleration device with long-time, high-overload and stable acceleration comprises a gas high-pressure chamber and a guide cylinder sealed with the gas high-pressure chamber. A quick-response pressure relief device is provided at one end of the gas high-pressure chamber connected to the guide cylinder. A friction sleeve and a friction transmission member that are plugged into each other are provided at the end of the guide cylinder away from the quick-response pressure relief device. An accelerated object is provided at the end of the friction transmission member. During launch, after the quick-response pressure relief device is damaged, the high-pressure gas in the gas high-pressure chamber rushes out to push the friction sleeve to move. The kinetic friction force generated by the relative sliding of the friction sleeve and the friction transmission member provides acceleration for the friction transmission member, and the friction transmission member pushes the accelerated object to perform stable accelerated motion in the guide cylinder.

[0005] In one embodiment, a counterweight and a compressible structure connected to the counterweight are provided in the guide cylinder near the quick response pressure relief device. The counterweight is sealed to the guide cylinder. During launch, after the quick response pressure relief device is damaged, the high-pressure gas in the gas high-pressure chamber rushes out to push the counterweight and the compressible structure to accelerate in the guide cylinder. After the counterweight and the compressible structure reach a preset speed, they hit the friction sleeve, and the compressible structure collapses until it has the same speed as the friction sleeve. The kinetic friction force generated by the relative sliding of the friction sleeve and the friction transmission member provides acceleration for the friction transmission member, and the friction transmission member pushes the accelerated object to perform stable accelerated motion in the guide cylinder.

[0006] In one embodiment, the compressible structure is a variable density porous structure, and the platform stress at one end of the compressible structure close to the friction sleeve is smaller than the platform stress at the other end.

[0007] In one embodiment, the compressible structure is a honeycomb structure, a thin-walled cylindrical structure, a thin-walled square hole structure, or an origami structure.

[0008] In one embodiment, the friction sleeve includes an outer sleeve and an inner sleeve arranged in an annular manner, and the outer wall of the friction transmission member is in contact with both the inner wall of the outer sleeve and the outer wall of the inner sleeve of the friction sleeve.

[0009] In one embodiment, the inner cylinder includes a plurality of concentrically arranged first annular members, the friction transmission member includes a plurality of concentrically arranged second annular members, and the outer wall of each second annular member of the friction transmission member fits with the inner wall of the corresponding first annular member of the friction sleeve.

[0010] In one embodiment, a buffer braking device is provided between the friction transmission member and the accelerated object.

[0011] In one embodiment, the buffer brake device includes an elastic member disposed at one end close to the friction transmission member and a rubber pad disposed at the other end of the elastic member.

[0012] Based on the same inventive concept, a control method for a friction acceleration device with long-time sequence, high overload and stable acceleration as described above is also provided, comprising:

[0013] Pre-filling the gas high-pressure chamber with high-pressure gas;

[0014] The control system provides signal excitation;

[0015] The gas high-pressure chamber absorbs heat, increases temperature and pressure, and the fast-response pressure relief device breaks open. The high-pressure gas rushes out and pushes the friction sleeve to move. The kinetic friction force generated by the relative sliding of the friction sleeve and the friction transmission part provides acceleration for the friction transmission part, and the friction transmission part pushes the accelerated object to perform stable accelerated motion in the guide cylinder.

[0016] In one embodiment, after the quick response pressure relief device breaks, high-pressure gas rushes out to push the counterweight and the compressible structure to accelerate in the guide tube; after the counterweight and the compressible structure reach a preset speed, they hit the friction sleeve, and the compressible structure collapses until it is at the same speed as the friction sleeve. The kinetic friction force generated by the relative sliding of the friction sleeve and the friction transmission member provides acceleration for the friction transmission member, and the friction transmission member pushes the accelerated object to perform stable accelerated motion in the guide tube.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: in the friction acceleration device with long-time high-overload stable acceleration of the present application, the high-pressure gas in the gas high-pressure chamber absorbs heat, increases temperature and pressure, and when the limit pressure is reached, the fast-response pressure relief device breaks open, and the high-pressure gas pushes the friction sleeve to move, providing initial power. The kinetic friction force generated by the relative sliding of the friction sleeve and the friction transmission part provides acceleration for the friction transmission part, and the friction transmission part pushes the accelerated object to perform stable accelerated motion in the guide cylinder. The kinetic friction force generated by the relative sliding of the friction sleeve and the friction transmission part can provide an equally stable overload value when it is relatively stable. The relative sliding distance and sliding length of the friction sleeve and the friction transmission part can be designed according to the required overload value duration. Compared to accelerators that directly use high-pressure gas to power the accelerated object, as the gas expands and its temperature decreases, the pressure rapidly decays, making it difficult to maintain stable acceleration over a long period of time. The present invention utilizes the kinetic friction generated by a friction sleeve and a friction transmission element. Since the magnitude of the friction coefficient depends primarily on the material and surface conditions of the contact surface, once the materials and contact surfaces of the friction sleeve and friction transmission element are determined, the friction coefficient is stable and the kinetic friction does not vary significantly, thus providing stable acceleration over a long period of time for the accelerated object. Furthermore, a counterweight and a compressible structure connected to the counterweight are positioned within the guide cylinder near the fast-response pressure relief device. The counterweight provides a certain initial weight. The heavier the counterweight and compressible structure, the higher the kinetic energy required to accelerate to the same speed. Therefore, if the accelerated object needs to be accelerated to the same speed, different initial kinetic energies can be achieved by adjusting the weight of the counterweight. Furthermore, the counterweight also serves to separate the compressible structure from the high-pressure gas chamber, allowing the high-pressure gas to act on the counterweight. Furthermore, the initial contact length between the friction sleeve and the friction transmission member can be adjusted by the preset length of the friction segment, thereby realizing an overload curve with a rising edge. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1Schematic diagram of the structure of a friction acceleration device with long-time sequence, high overload and stable acceleration according to one embodiment;

[0020] Figure 2 This is a structural schematic diagram of a friction acceleration device with long-time high-overload stable acceleration in another embodiment. DETAILED DESCRIPTION

[0021] To facilitate understanding of the present invention, the present invention will be described in more comprehensive and detailed form below in conjunction with the accompanying drawings and preferred embodiments. However, the protection scope of the present invention is not limited to the following specific embodiments.

[0022] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0023] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0024] See also Figure 1-2A friction acceleration device with long-time high-overload stable acceleration includes a gas high-pressure chamber 1 and a guide cylinder 5 sealed with the gas high-pressure chamber. A fast-response pressure relief device 2 is provided at one end of the gas high-pressure chamber 1 connected to the guide cylinder 5. A counterweight 3 and a compressible structure 4 connected to the counterweight 3 are provided in the guide cylinder 5 near the fast-response pressure relief device 2. A friction sleeve 6 and a friction transmission member 8 that are plugged into each other are provided at the end of the guide cylinder 5 away from the fast-response pressure relief device 2. The contact section between the friction sleeve 6 and the friction transmission member 8 is a friction section 7. An accelerated object 11 is provided at the end of the friction transmission member 8. During launch, after the quick-response pressure relief device 2 breaks, the high-pressure gas in the gas high-pressure chamber 1 rushes out, pushing the counterweight 3 and compressible structure 4 to accelerate within the guide tube. After reaching a preset speed, the counterweight 3 and compressible structure 4 strike the friction sleeve 6, causing the compressible structure 4 to collapse until it reaches the same speed as the friction sleeve 6. The kinetic friction generated by the relative sliding of the friction sleeve 6 and the friction transmission member 8 provides acceleration for the friction transmission member 8, which in turn propels the accelerated object 11 to achieve stable accelerated motion within the guide tube 5. By increasing the acceleration distance, the required acceleration of the counterweight 3 and compressible structure 4 can be reduced, thereby lowering the gas pressure requirement of the gas high-pressure chamber 1 and reducing the structural safety requirements. The counterweight 3 provides a certain initial weight. The heavier the counterweight 3 and compressible structure 4 (compressible structure 4 is relatively light due to its inherent structural and material properties), the higher the kinetic energy required to accelerate to the same speed. Therefore, in multiple acceleration tests, the accelerated object 11 needs to be accelerated to the same speed, and different initial kinetic energies can be achieved by adjusting the weight of the counterweight 3. Furthermore, the counterweight 3 also serves to separate the compressible structure 4 from the high-pressure gas chamber 1. The counterweight 3 forms a sealed space between the high-pressure gas chamber 1 and the guide cylinder 5, allowing high-pressure gas to act on the counterweight 3. Because the compressible structure 4 is a variable-density porous structure, without the isolation provided by the counterweight 3, the high-pressure gas from the high-pressure gas chamber 1 would pass through the pores of the compressible structure 4, preventing it from accelerating.

[0025] In another embodiment, the counterweight 3 and the compressible structure 4 connected to the counterweight 3 may not be provided. During launch, the high-pressure gas in the gas high-pressure chamber 1 absorbs heat, increases in temperature and pressure, and when the ultimate pressure is reached, the quick-response pressure relief device 2 breaks open, and the high-pressure gas pushes the friction sleeve 6 to move, providing initial power. The kinetic friction generated by the relative sliding of the friction sleeve 6 and the friction transmission member 8 provides acceleration for the friction transmission member 8, which pushes the accelerated object 11 to perform stable accelerated motion within the guide tube 5. The kinetic friction generated by the relative sliding of the friction sleeve 6 and the friction transmission member 8 can provide a similarly stable overload value when relatively stable. When the counterweight 3 and the compressible structure 4 connected to the counterweight 3 are not provided, the gas pressure requirements for the gas high-pressure chamber 1 are higher, and the requirements for structural safety are also higher.

[0026] Specifically, in one embodiment, the fast-response pressure relief device 2 is a pressure relief diaphragm with prefabricated grooves. The diaphragm seals and holds pressure until the pressure within the high-pressure gas chamber 1 reaches the diaphragm's limit pressure. When the pressure within the high-pressure gas chamber 1 reaches the diaphragm's limit pressure, the diaphragm ruptures and rapidly releases pressure into the guide cylinder 5. Of course, the fast-response pressure relief device 2 may also have other structures, such as a ring shear member.

[0027] Specifically, in one embodiment, the compressible structure 4 is a variable-density porous structure, and the plateau stress at one end of the compressible structure 4 near the friction sleeve 6 is lower than the plateau stress at the other end. In the initial compression phase after impact, the product of the plateau stress and cross-sectional area of ​​the compressible structure 4 is less than the dynamic friction force. In the later phase, the product of the plateau stress and cross-sectional area is greater than the dynamic friction force. During the impact process, the initial compression phase of the compressible structure 4 primarily serves as a buffer. The initial crushing force is lower than the later crushing force, allowing the compressible structure 4 to move forward against the friction sleeve 6, thereby achieving relative motion between the friction sleeve 6 and the friction transmission member 8. During the initial phase of the impact between the compressible structure 4 and the friction sleeve 6, the plateau stress in the portion of the compressible structure 4 near the friction sleeve 6 is lower, providing a buffering effect and preventing transient acceleration from exceeding the limit. When compressible structure 4 collapses to the higher platform stress section, it stops collapsing and reaches the same speed as friction sleeve 6. Friction sleeve 6 and friction transmission member 8 begin to slide relative to each other, generating dynamic friction that begins to accelerate friction transmission member 8. A relatively stable dynamic friction force can provide a similarly stable overload value, thereby providing stable acceleration for accelerated object 11. Specifically, the length of friction section 7 between friction sleeve 6 and friction transmission member 8 can be designed based on the required duration of the overload value for accelerated object 11.

[0028] In one embodiment, the compressible structure 4 is a honeycomb structure, a thin-walled cylindrical structure, a thin-walled square hole structure, or an origami structure.

[0029] Specifically, the friction sleeve 6 comprises an outer sleeve disposed within the guide sleeve 5 and an inner sleeve disposed within the outer sleeve. Preferably, the outer and inner sleeves are concentrically disposed, and the outer wall of the friction transmission member 8 mates with both the outer and inner sleeve inner walls of the friction sleeve 6. Preferably, to provide greater dynamic friction, in one embodiment, the inner sleeve comprises a plurality of concentrically disposed first annular members, and the friction transmission member 8 comprises a plurality of concentrically disposed second annular members, with the outer wall of each second annular member of the friction transmission member mates with the inner wall of the corresponding first annular member of the friction sleeve.

[0030] During the friction process between the friction sleeve 6 and the friction transmission member 8, the compression amount and unit area pressure preset by the compressible structure 4 are Forming positive pressure on the friction transmission member 8, the dynamic friction coefficient is , S is the contact area between the friction sleeve 6 and the friction transmission member 8. According to the inner and outer wall radius r1 and r2 of the ring and the length l of the friction section 7 between the friction sleeve 6 and the friction transmission member 8, the contact area between the friction sleeve 6 and the friction transmission member 8 can be obtained. The kinetic friction force is obtained as In order to obtain higher dynamic friction and overload value, when the inner tube of the friction sleeve 6 includes multiple concentrically arranged first annular members and the friction transmission member 8 includes multiple concentrically arranged second annular members, the dynamic friction should be .

[0031] Preferably, in one embodiment, a buffer brake device is provided between the friction transmission member 8 and the accelerated object 11. The buffer brake device comprises an elastic member 10 disposed near one end of the friction transmission member 8 and a rubber pad 9 disposed at the other end of the elastic member 10. Preferably, the elastic member 10 is a relatively high-rigidity spring. In an emergency, the buffer brake device provides a braking measure for the accelerated object 11 to prevent direct collision with a hard object from generating acceleration exceeding a set value.

[0032] Based on the same inventive concept, a control method for a friction acceleration device with long-time sequence, high overload and stable acceleration as described above is also provided, comprising:

[0033] S10, pre-filling the gas high-pressure chamber with high-pressure gas;

[0034] S20, the control system provides a signal excitation;

[0035] S30. The gas high-pressure chamber absorbs heat, increases temperature and pressure, and the quick-response pressure relief device breaks open. The high-pressure gas rushes out and pushes the friction sleeve to move. The kinetic friction force generated by the relative sliding of the friction sleeve and the friction transmission part provides acceleration for the friction transmission part, and the friction transmission part pushes the accelerated object to perform stable accelerated motion in the guide cylinder.

[0036] Specifically, in the case where the friction acceleration device with long-term high-overload stable acceleration includes a counterweight 3 and a compressible structure 4, after the quick-response pressure relief device 2 breaks, the high-pressure gas rushes out to push the counterweight 3 and the compressible structure 4 to accelerate in the guide tube 5; after the counterweight 3 and the compressible structure 4 reach a preset speed, they collide with the friction sleeve 6, and the compressible structure 4 collapses until it is at the same speed as the friction sleeve 6. The kinetic friction force generated by the relative sliding of the friction sleeve 6 and the friction transmission member 8 provides acceleration for the friction transmission member 8, and the friction transmission member 8 pushes the accelerated object 11 to perform stable accelerated motion in the guide tube 5.

[0037] Example 1: A friction acceleration device with long-time high-overload stable acceleration includes a gas high-pressure chamber 1 and a guide cylinder 5 connected to the gas high-pressure chamber. A fast-response pressure relief device 2 is provided at one end of the gas high-pressure chamber 1 connected to the guide cylinder 5. A counterweight 3 and a compressible structure 4 connected to the counterweight 3 are provided in the guide cylinder 5 near the fast-response pressure relief device 2. A friction sleeve 6 and a friction transmission member 8 that are plugged into each other are provided at one end of the guide cylinder 5 away from the fast-response pressure relief device 2. The contact section between the friction sleeve 6 and the friction transmission member 8 is a friction section 7. An accelerated object 11 is provided at the end of the friction transmission member 8. An elastic member 10 and a rubber pad 9 are provided between the friction transmission member 8 and the accelerated object 11 at the end close to the friction transmission member 8.

[0038] Example 2: The difference from Example 2 is that the counterweight 3 and the compressible structure 4 connected to the counterweight 3 are not provided.

[0039] Tables 1 and 2 give the relevant parameters of the two examples.

[0040] Table 1 Parameters related to Example 1

[0041]

[0042] Table 2 Parameters related to Example 2

[0043]

[0044] Both methods use high-pressure gas to provide initial kinetic energy, and then utilize friction sleeves and friction transmission parts to provide high overload loading. Compared with directly using high-pressure gas impact force for high overload loading, since the friction factor does not change much, its overload value is more stable. At the same time, its analysis process is also simpler, and there is no need to consider the platform stress changes of the impact force transmission structure and perform special design of gradient density or variable cross-sectional area.

[0045] It can be seen that Example 2 requires a higher high-pressure gas pressure than Example 1, and therefore has higher requirements for structural safety. Example 1 can reduce the required gas pressure by lengthening the acceleration distance and reducing the acceleration of the counterweight 3 and the compressible structure 4, thereby reducing the structural safety requirements.

Claims

1. A friction acceleration device with long time sequence, high overload and stable acceleration, characterized in that: It includes a gas high-pressure chamber and a guide cylinder sealed with the gas high-pressure chamber. A fast-response pressure relief device is provided at one end of the gas high-pressure chamber connected to the guide cylinder. A friction sleeve and a friction transmission member are provided at the end of the guide cylinder away from the fast-response pressure relief device. An accelerated object is provided at the end of the friction transmission member. During launch, after the fast-response pressure relief device is damaged, the high-pressure gas in the gas high-pressure chamber rushes out to push the friction sleeve to move. The kinetic friction force generated by the relative sliding of the friction sleeve and the friction transmission member provides acceleration for the friction transmission member, and the friction transmission member pushes the accelerated object to perform stable accelerated motion in the guide cylinder. A counterweight and a compressible structure connected to the counterweight are provided in the guide tube near the quick-response pressure relief device. The counterweight is sealed against the guide tube. During launch, after the quick-response pressure relief device is damaged, the high-pressure gas in the gas high-pressure chamber rushes out, pushing the counterweight and the compressible structure to accelerate in the guide tube. After the counterweight and the compressible structure reach a preset speed, they collide with the friction sleeve, causing the compressible structure to collapse until it reaches the same speed as the friction sleeve. The kinetic friction generated by the relative sliding of the friction sleeve and the friction transmission member provides acceleration for the friction transmission member, which in turn pushes the accelerated object to perform stable accelerated motion in the guide tube. The compressible structure is a variable density porous structure, and the platform stress at one end of the compressible structure close to the friction sleeve is smaller than the platform stress at the other end; The compressible structure is a honeycomb structure, a thin-walled cylindrical structure, a thin-walled square hole structure or an origami structure; The friction sleeve comprises an outer sleeve and an inner sleeve arranged in an annular manner, and the outer wall of the friction transmission member is in contact with both the inner wall of the outer sleeve and the outer wall of the inner sleeve of the friction sleeve; The inner cylinder includes a plurality of concentrically arranged first annular members, and the friction transmission member includes a plurality of concentrically arranged second annular members. The outer wall of each second annular member of the friction transmission member fits with the inner wall of the first annular member corresponding to the friction sleeve.

2. The friction acceleration device with long time sequence, high overload and stable acceleration according to claim 1, characterized in that: A buffer braking device is provided between the friction transmission member and the accelerated object.

3. The friction acceleration device with long time sequence, high overload and stable acceleration according to claim 2, characterized in that: The buffer brake device comprises an elastic member arranged at one end close to the friction transmission member and a rubber pad arranged at the other end of the elastic member.

4. A control method for a friction acceleration device with long-time sequence, high overload and stable acceleration according to any one of claims 1 to 3, characterized in that: include: Pre-filling the gas high-pressure chamber with high-pressure gas; The control system provides signal excitation; The gas high-pressure chamber absorbs heat, increases temperature and pressure, and the fast-response pressure relief device breaks open. The high-pressure gas rushes out and pushes the friction sleeve to move. The kinetic friction force generated by the relative sliding of the friction sleeve and the friction transmission part provides acceleration for the friction transmission part, and the friction transmission part pushes the accelerated object to perform stable accelerated motion in the guide cylinder.

5. The control method of the friction acceleration device with long-time high-overload stable acceleration according to claim 4 is characterized in that: After the quick response pressure relief device breaks open, the high-pressure gas rushes out and pushes the counterweight and the compressible structure to accelerate in the guide tube; after the counterweight and the compressible structure reach the preset speed, they hit the friction sleeve, and the compressible structure collapses until it has the same speed as the friction sleeve. The kinetic friction force generated by the relative sliding of the friction sleeve and the friction transmission part provides acceleration for the friction transmission part, and the friction transmission part pushes the accelerated object to perform stable accelerated motion in the guide tube.

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