Long-time-sequence high-overload stable acceleration friction acceleration device and control method thereof

Abstract

The invention belongs to the technical field of impact tests, and discloses a long-time-sequence high-overload stable-acceleration friction acceleration device which comprises a gas high-pressure chamber and a guide cylinder connected with the gas high-pressure chamber, and one end, connected with the guide cylinder, of the gas high-pressure chamber is provided with a quick-response pressure relief device. One end, far away from the quick response pressure relief device, of the guide cylinder is provided with a friction sleeve and a friction transmission piece which are mutually connected in an inserted mode, and the end of the friction transmission piece is provided with an accelerated object, and during launching, after the quick response pressure relief device is damaged, high-pressure gas in the gas high-pressure chamber rushes out to push the friction sleeve to move; dynamic friction force generated by relative sliding of the friction sleeve and the friction transmission piece provides acceleration for the friction transmission piece, and the friction transmission piece pushes an accelerated object to do stable acceleration motion in the guide cylinder. The invention further provides a corresponding control method. The acceleration device and the control method can provide long-time-sequence stable acceleration.

Description

Technical Field

[0001] The 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 acceleration devices usually directly use power sources (such as electromagnetic force, high-pressure gas, etc.) to accelerate objects that need to be accelerated. When the accelerated object needs to be accelerated at ultra-high acceleration, the system is usually required to generate a huge thrust instantly, with a power of several thousand megawatts. At present, with the use of more electric acceleration equipment, it is almost impossible to achieve a power consumption and scale of several thousand megawatts. For explosive impact acceleration, the duration of high acceleration is only microseconds, and the temperature of the gas released during the process reaches thousands of degrees Celsius, which cannot sustain high pressure and reduces the safety of the device. Traditional rocket engine gas generators usually have a pressure of only about 10 MPa, and like explosive impact, they use pyrotechnics, and the temperature of the released gas is as high as 1000 degrees Celsius, which reduces the safety of the device. When using compressed air drive, the pressure required to continuously promote acceleration is above hundreds of megapascals. On the one hand, it is difficult to form compressed air of hundreds of megapascals. On the other hand, the high-pressure air power source will decay rapidly after generating explosive driving force, and the high pressure cannot be sustained, resulting in the acceleration time not meeting the requirements and unable to obtain stable acceleration. In the compressed air drive method, the use of carbon dioxide liquid-gas phase change catapult can achieve high overload loading of the target object at a relatively low cost, but 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 deficiencies and defects mentioned in the above background technology and provide a friction acceleration device and a control method thereof that can provide long-time stable acceleration with high overload. In order to solve the above technical problem, the technical solution proposed by the present invention is: A friction acceleration device with long-time high-overload stable acceleration includes a gas high-pressure chamber and a guide cylinder sealed with the gas high-pressure chamber, one end of the gas high-pressure chamber connected to the guide cylinder is provided with a fast-response pressure relief device, one end of the guide cylinder away from the fast-response pressure relief device is provided with a friction sleeve and a friction transmission member that are plugged into each other, and 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, and 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.

[0004] 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, and 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.

[0005] 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.

[0006] 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.

[0007] In one embodiment, the friction sleeve includes an outer sleeve and an inner sleeve which are 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.

[0008] 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 first annular member corresponding to the friction sleeve.

[0009] In one embodiment, a buffer brake device is provided between the friction transmission member and the accelerated object.

[0010] 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.

[0011] 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: 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 quick-response pressure relief device breaks open. The high-pressure gas rushes out and pushes the friction sleeve to move. The dynamic 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.

[0012] In one embodiment, after the quick response pressure relief device breaks open, the 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 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 tube.

[0013] 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 to increase the temperature and pressure. 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 dynamic friction force generated by the relative sliding of the friction sleeve and the friction transmission part provides acceleration for the friction transmission part. The friction transmission part pushes the accelerated object to perform stable accelerated motion in the guide cylinder. The dynamic 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 with the acceleration device that directly uses high-pressure gas to provide a power source for the accelerated object, the gas volume expands and the temperature decreases, and the pressure decays rapidly, making it difficult to maintain a long-term stable acceleration. The present application uses the dynamic friction force generated by the friction sleeve and the friction transmission member. Since the magnitude of the friction coefficient mainly depends on the material and surface conditions of the contact surface, the friction coefficient is stable after the material and contact surface of the friction sleeve and the friction transmission member are determined, and the dynamic friction force does not change much before and after, so it can provide a long-term stable acceleration for the accelerated object. Furthermore, a counterweight and a compressible structure connected to the counterweight are provided near the fast response pressure relief device in the guide cylinder. The counterweight provides a certain initial weight. The heavier the counterweight and the 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. In addition, the counterweight also bears the responsibility of separating the compressible structure and the gas high-pressure chamber so that the high-pressure gas can 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

[0014] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0015] Figure 1It is a structural schematic diagram of a friction acceleration device with long-time sequence, high overload and stable acceleration according to one embodiment; Figure 2 It is a schematic structural diagram of a friction acceleration device with long-time high-overload stable acceleration according to another embodiment. DETAILED DESCRIPTION

[0016] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.

[0017] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional 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.

[0018] 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.

[0019] 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 and 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 are inserted into each other 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. During launch, after the quick response pressure relief device 2 is damaged, the high pressure gas in the gas high pressure chamber 1 rushes out to push the counterweight 3 and the compressible structure 4 to accelerate in the guide tube. After the counterweight 3 and the compressible structure 4 reach the preset speed, they hit the friction sleeve 6, and the compressible structure 4 is crushed 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. By lengthening the acceleration distance, the required acceleration of the counterweight 3 and the compressible structure 4 can be reduced, thereby reducing the gas pressure requirement of the gas high pressure chamber 1 and the structural safety requirement. The counterweight 3 provides a certain initial weight. The heavier the counterweight 3 and the compressible structure 4 are (the compressible structure 4 is relatively light due to its own structure and material characteristics), 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. In addition, the counterweight 3 is also responsible for separating the compressible structure 4 from the gas high-pressure chamber 1. The counterweight 3 forms a sealed space between the gas high-pressure chamber 1 and the guide cylinder 5 so that the high-pressure gas can act on the counterweight 3. Since the compressible structure 4 is a variable-density porous structure, if there is no isolation effect of the counterweight 3, the high-pressure gas from the gas high-pressure chamber 1 will pass through the pore structure of the compressible structure 4 and cannot push the compressible structure to accelerate.

[0020] 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 temperature and pressure, and when the limit pressure is reached, the fast response pressure relief device 2 is broken, and the high-pressure gas pushes the friction sleeve 6 to move, providing initial power. The dynamic 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. The friction transmission member 8 pushes the accelerated object 11 to perform stable acceleration movement in the guide tube 5. The dynamic friction force generated by the relative sliding of the friction sleeve 6 and the friction transmission member 8 can provide a similarly stable overload value when it is relatively stable. When the counterweight 3 and the compressible structure 4 connected to the counterweight 3 are not provided, the gas pressure requirements of the gas high-pressure chamber 1 are higher, and the requirements for structural safety are also higher.

[0021] Specifically, in one embodiment, the fast response pressure relief device 2 is a pressure relief diaphragm, which is provided with a prefabricated groove, and is sealed and pressure-holding before the pressure in the gas high pressure chamber 1 reaches the limit pressure of the pressure relief diaphragm. When the pressure in the gas high pressure chamber 1 reaches the limit pressure of the pressure relief diaphragm, it breaks and quickly releases pressure into the guide cylinder 5. Of course, the fast response pressure relief device 2 can also be other structures, such as a ring shear member, etc.

[0022] Specifically, in one embodiment, the compressible structure 4 is a variable density porous structure, and the platform stress at one end of the compressible structure 4 close to the friction sleeve 6 is smaller than the platform stress at the other end. The product of the platform stress and the cross-sectional area in the initial compression section after the impact of the compressible structure 4 is smaller than the dynamic friction force, and the product of the platform stress and the cross-sectional area in the later section is larger than the dynamic friction force. During the impact of the compressible structure 4, its initial compression section mainly plays a buffering role. The crushing force at the beginning of the crushing is smaller than the crushing force in the later period, so that the compressible structure 4 can move forward with the friction sleeve 6, so that the friction sleeve 6 and the friction transmission member 8 have relative movement. In the initial stage of the impact between the compressible structure 4 and the friction sleeve 6, the platform stress of the part of the compressible structure 4 close to the friction sleeve 6 is small, which can play a buffering role and avoid instantaneous acceleration exceeding the limit. When the compressible structure 4 is compressed to the section with higher platform stress, the compressible structure 4 stops compressing and reaches the same speed as the friction sleeve 6. The friction sleeve 6 and the friction transmission member 8 slide relative to each other, and the dynamic friction force generated by the two begins to provide acceleration for the friction transmission member 8. When the dynamic friction force is relatively stable, it can provide a similarly stable overload value, thereby providing a stable acceleration for the accelerated object 11. Specifically, according to the duration of the overload value required by the accelerated object 11, the length of the friction section 7 of the friction sleeve 6 and the friction transmission member 8 can be designed.

[0023] 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.

[0024] Specifically, the friction sleeve 6 includes an outer sleeve disposed in the guide sleeve 5 and an inner sleeve disposed in the outer sleeve. Preferably, the outer sleeve and the inner sleeve are concentrically disposed, and the outer wall of the friction transmission member 8 is in contact with both the inner wall of the outer sleeve and the outer wall of the inner sleeve of the friction sleeve 6. Preferably, in order to provide greater dynamic friction, in one embodiment, the inner sleeve includes a plurality of concentrically disposed first annular members, and the friction transmission member 8 includes a plurality of concentrically disposed second annular members, and the outer wall of each second annular member of the friction transmission member is in contact with the inner wall of the corresponding first annular member of the friction sleeve.

[0025] 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 a 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 wall radius r1 and the outer wall radius r2 of the ring and the length l of the friction section 7 of 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 dynamic friction force is In order to obtain higher dynamic friction and overload value, when the inner cylinder of the friction sleeve 6 includes a plurality of concentrically arranged first annular members, and the friction transmission member 8 includes a plurality of concentrically arranged second annular members, the dynamic friction should be .

[0026] Preferably, in one embodiment, a buffer brake device is provided between the friction transmission member 8 and the accelerated object 11, and the buffer brake device comprises an elastic member 10 disposed at one end close to 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 spring with high stiffness. In an emergency, a braking measure is provided for the accelerated object 11 to prevent a hard object from directly colliding and generating an acceleration exceeding a set value.

[0027] 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: S10, pre-charging the gas high pressure chamber with high pressure gas; S20, the control system provides a signal excitation; S30. The gas high-pressure chamber absorbs heat and increases temperature and pressure. The fast-response pressure relief device breaks open, and the high-pressure gas rushes out to push the friction sleeve to move. The dynamic 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.

[0028] Specifically, in the case where the friction acceleration device for long-time high-overload stable acceleration includes a counterweight 3 and a compressible structure 4, after the quick-response pressure relief device 2 is broken, 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 hit the friction sleeve 6, and the compressible structure 4 collapses until it has 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.

[0029] Embodiment 1: A friction acceleration device with long-time high-overload stable acceleration comprises a gas high-pressure chamber 1 and a guide cylinder 5 connected to the gas high-pressure chamber, a quick-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 quick-response pressure relief device 2, a friction sleeve 6 and a friction transmission member 8 which are plugged into each other are provided at one end of the guide cylinder 5 away from the quick-response pressure relief device 2, a friction section 7 is formed where the friction sleeve 6 and the friction transmission member 8 contact each other, 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.

[0030] Embodiment 2: The difference from the embodiment 2 is that the counterweight 3 and the compressible structure 4 connected to the counterweight 3 are not provided.

[0031] Tables 1 and 2 give the relevant parameters of the two examples.

[0032] Table 1 Parameters related to Example 1

[0033] Table 2 Parameters related to Example 2

[0034] Both methods use high-pressure gas to provide initial kinetic energy, and then use 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, the overload value is more stable. At the same time, the 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 designs of gradient density or variable cross-sectional area.

[0035] It can be seen that, compared with Example 1, Example 2 requires a higher high-pressure gas pressure, and therefore has a higher requirement 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 requirement.

Claims

1. A friction acceleration device with long-time high overload stable acceleration, characterized in that: It includes 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 which are plugged into each other are provided at one 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. The friction transmission member pushes the accelerated object to perform stable accelerated motion in the guide cylinder.

2. The friction acceleration device with long-time sequence, high overload and stable acceleration according to claim 1, characterized in that: 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 with 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 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 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.

3. The friction acceleration device with long-time sequence, high overload and stable acceleration according to claim 2, characterized in that: 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.

4. The friction acceleration device with long-time sequence, high overload and stable acceleration according to claim 3 is characterized in that: The compressible structure is a honeycomb structure, a thin-walled cylindrical structure, a thin-walled square hole structure or an origami structure.

5. The friction acceleration device with long-time sequence, high overload and stable acceleration according to claim 1, characterized in that: The friction sleeve comprises an outer sleeve and an inner sleeve which are arranged in an annular manner. The outer wall of the friction transmission component is in contact with both the inner wall of the outer sleeve and the outer wall of the inner sleeve of the friction sleeve.

6. The friction acceleration device with long-time sequence, high overload and stable acceleration according to claim 5, characterized in that: 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, and the outer wall of each second annular member of the friction transmission member is in contact with the inner wall of the first annular member corresponding to the friction sleeve.

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

8. The friction acceleration device with long-time sequence, high overload and stable acceleration according to claim 7, 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.

9. 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 8, 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 quick-response pressure relief device breaks open. The high-pressure gas rushes out and pushes the friction sleeve to move. The dynamic 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.

10. The control method of the friction acceleration device with long-time high overload stable acceleration according to claim 9 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 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 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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