Low pressure environment vibration test system dynamic center holding device

Abstract

The present invention discloses a dynamic coil center maintaining device for a low-pressure environment vibration test system, comprising a pressure-bearing platform and a comprehensive test box. The pressure-bearing platform is provided with a dynamic coil, and the upper part of the dynamic coil passes through a dynamic coil through-hole on the pressure-bearing platform and extends into the comprehensive test box. A test sealing cavity is formed between the dynamic coil and the comprehensive test box. A sealing rolling film for sealing the pressure-bearing platform and the dynamic coil is provided at the dynamic coil through-hole. A pressure-bearing sealing cavity is formed between the pressure-bearing platform, the dynamic coil and the sealing rolling film. A weighing sensor is installed at the top end of the dynamic coil extending into the test sealing cavity. The weighing sensor is electrically connected to an air pressure dynamic balancing device, which can enable the dynamic coil to maintain equal upper and lower air pressures and balanced forces during operation, thereby maintaining small-amplitude and high-frequency vibration.

Description

Technical Field

[0001] The present invention relates to the technical field of composite environment vibration test devices, in particular to a dynamic center holding device for a low-pressure environment vibration test system. Background Art

[0002] The four comprehensive tests refer to the comprehensive tests of humidity, temperature, vibration and low pressure. The four comprehensive test system is suitable for testing the performance indicators of materials, electrical and electronic products, aerospace products, information electronic instruments and various electronic components under temperature, humidity, vibration and low pressure environments.

[0003] When conducting a low-pressure vibration test, the interior of the integrated test chamber needs to be evacuated to stabilize it in a low-pressure environment. To address the problem of the dynamic coil being unable to maintain small-amplitude, high-frequency vibrations due to an imbalance in the air pressure between the inner cavity of the pressure-bearing platform and the internal pressure of the integrated test chamber, Chinese invention patent publication number CN205333276U discloses a low-pressure environment vibration test system. The sealed cavity of the test chamber and the sealed cavity of the vibration table are connected to the same vacuum pump via a vacuum tube, and a vacuum pump is performed to achieve constant pressure in the two sealed cavities. However, to ensure that the upper and lower forces on the dynamic coil of the vibration table are equal and to maintain a small-amplitude, high-frequency, stable vibration of the dynamic coil of the vibration table, the areas of the upper and lower parts of the dynamic coil subjected to air pressure should be as equal as possible. Thus, although this vibration test system is more convenient for controlling pressure, it limits the upper and lower areas of the dynamic coil, and its scope of application is relatively small. Chinese invention patent publication number CN101408473 discloses a method and device for maintaining the center of a vibration table during a low-pressure and vibration composite test. The method first uses an eddy current sensor to measure the distance and direction of the table's static and dynamic deviation from the theoretical vibration center position, converting the displacement into an electrical signal. The electrical signal output by the sensor then enters a controller, which controls the inflation and deflating of a rigid air chamber using one inflation path and two exhaust paths, ensuring the table maintains its vibration center position during the test. However, to better meet the requirements of varying exhaust volumes, the two exhaust paths require different calibers, and a proportional valve is also required in the second exhaust path to control the exhaust volume. This provides good control but is relatively complex. Furthermore, due to structural design issues, current electromagnetic vibration tables often experience rapid descent due to the influence of heavy objects or during vacuuming of the integrated test chamber, even when the pressures in the enclosed cavities above and below the moving coil are equal. This can damage the moving coil and prevent subsequent vibration testing. Summary of the Invention

[0004] In response to the above-mentioned technical deficiencies, the purpose of the present invention is to provide a dynamic coil center holding device for a low-pressure environment vibration test system, which can enable the dynamic coil to maintain equal upper and lower air pressures and balanced forces during operation, thereby maintaining small-amplitude and high-frequency vibrations.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The present invention provides a dynamic coil center holding device for a low-pressure environment vibration test system, comprising a pressure-bearing platform and a comprehensive test box, wherein a dynamic coil is arranged in the pressure-bearing platform, and the upper part of the dynamic coil extends into the comprehensive test box through the dynamic coil through-hole on the pressure-bearing platform, and a test sealing cavity is formed between the dynamic coil and the comprehensive test box, and a sealing rolling film for sealing the pressure-bearing platform and the dynamic coil is arranged at the dynamic coil through-hole, and a pressure-bearing sealing cavity is formed between the pressure-bearing platform, the dynamic coil and the sealing rolling film, and a weighing sensor for measuring the weight of a loaded object is installed on the top end of the dynamic coil extending into the test sealing cavity, and the weighing sensor is electrically connected to an air pressure dynamic balancing device, and the air pressure dynamic coil is provided with a pressure-bearing sealing device. A balancing iron core is provided in the dynamic balancing device, an upper sealed cavity is formed between the upper end surface of the balancing iron core and the inner wall of the air pressure dynamic balancing device, a lower sealed cavity is formed between the lower end surface of the balancing iron core and the inner wall of the air pressure dynamic balancing device, the upper sealed cavity is connected with the test sealed cavity through pipe A, the lower sealed cavity is connected with the pressure sealed cavity through pipe B, an exhaust pipe C is provided on the air pressure dynamic balancing device, the balancing iron core is connected with a spring and a variable damper which can control the exhaust pipe C to be connected with the upper sealed cavity or the lower sealed cavity, the test sealed cavity is connected with a vacuum pipe, and the exhaust pipe C and the vacuum pipe are connected with a vacuum device.

[0007] Preferably, the upper end of the balancing iron core is fixed to the electromagnet A on the upper part of the pneumatic dynamic balancing device through a spring, and the lower end of the balancing iron core is fixed to the lower inner wall of the pneumatic dynamic balancing device through a variable damper.

[0008] Preferably, the electromagnet A is electrically connected to a weighing sensor.

[0009] Preferably, the sealing roller film is an elastic sealing film.

[0010] Preferably, blocks corresponding to the pipeline B are provided in the upper sealed cavity and the lower sealed cavity for preventing the test sealed cavity from communicating with the pressure-bearing sealed cavity.

[0011] Preferably, the stopper is welded and fixed to the inner wall of the air pressure dynamic balancing device and is located between pipe A and pipe B.

[0012] Preferably, the pressure-bearing sealed cavity is provided with an electromagnet B fixed to the inner wall of the pressure-bearing sealed cavity and a magnetic induction coil corresponding to the electromagnet B and sleeved on the outside of the moving coil.

[0013] The beneficial effects of the present invention are:

[0014] 1. The present invention is provided with an air pressure dynamic balancing device, which can avoid the phenomenon of unbalanced air pressure between the inner cavity of the pressure-bearing platform and the internal air pressure of the comprehensive test box. In addition, when the dynamic coil falls rapidly due to the influence of heavy objects, the balancing iron core can also be adjusted to enable the dynamic coil to maintain small-amplitude and high-frequency vibration.

[0015] 2. The present invention converts the weight of the loaded object into electromagnetic force by setting a weighing sensor, thereby better achieving the balance of the inner cavity of the pressure-bearing platform and the internal air pressure of the comprehensive test box. The control is more flexible and there is no need to set up a test table with the same area as the loaded object, so the scope of application is wider.

[0016] 3. The test sealed chamber and the pressure sealed chamber of the present invention are not interconnected, which can prevent moisture and foreign matter in the test sealed chamber environment from entering the pressure sealed chamber. The mutual isolation can avoid electromagnetic coil failure in the pressure sealed chamber.

[0017] 4. The present invention is provided with a spring and a damper corresponding to the balance iron core, which can consume the kinetic energy of the balance iron core and reduce the oscillation of the balance iron core. 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 only 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 1 Schematic diagram of the structure of an embodiment of the present invention.

[0020] Description of reference numerals:

[0021] 1. Pressure-bearing platform; 1a. Pressure-bearing sealed chamber; 1b. Moving coil through-hole; 2. Moving coil; 3. Magnetic induction coil; 4. Sealing roller; 5. Comprehensive test chamber; 5a. Test sealed chamber; 6. Weighing sensor; 7. Air pressure dynamic balancing device; 7a. Balancing iron core; 7b. Stop block; 8. Electromagnet B; 9. Electromagnet A; 10. Vacuum pipe; 11. Spring; 12. Variable damper. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, this embodiment provides a dynamic coil center holding device for a low-pressure environment vibration test system, including a pressure-bearing platform 1 and a comprehensive test box 5. A dynamic coil 2 is arranged in the pressure-bearing platform 1, and the upper part of the dynamic coil 2 passes through the dynamic coil through-hole 1b on the pressure-bearing platform 1 and extends into the comprehensive test box 5. A test sealing cavity 5a is formed between the dynamic coil 2 and the comprehensive test box 5. A sealing rolling film 4 for sealing the pressure-bearing platform 1 and the dynamic coil 2 is provided at the dynamic coil through-hole 1b. A pressure-bearing sealing cavity 1a is formed between the pressure-bearing platform 1, the dynamic coil 2, and the sealing rolling film 4. A weighing sensor 6 for measuring the weight of a loaded object is installed on the top of the dynamic coil 2 extending into the test sealing cavity 5a. The weighing sensor 6 is electrically connected to the air pressure dynamic balancing device 7. Then, a balancing iron core 7a is provided in the air pressure dynamic balancing device 7, an upper sealed cavity is formed between the upper end surface of the balancing iron core 7a and the inner wall of the air pressure dynamic balancing device 7, a lower sealed cavity is formed between the lower end surface of the balancing iron core 7a and the inner wall of the air pressure dynamic balancing device 7, the upper sealed cavity is connected with the test sealed cavity 5a through the pipe A, and the lower sealed cavity is connected with the pressure-bearing sealed cavity 1a through the pipe B, an exhaust pipe C is provided on the air pressure dynamic balancing device 7, the balancing iron core 7a is connected with a spring 11 and a variable damper 12 which can control the exhaust pipe C to be connected with the upper sealed cavity or the lower sealed cavity, the test sealed cavity 5a is connected with a vacuum pipe, and the exhaust pipe C and the vacuum pipe are connected with a vacuum device.

[0024] The upper end of the balancing iron core 7a is fixed to the electromagnet A9 on the upper part of the pneumatic dynamic balancing device 7 through a spring, and the lower end of the balancing iron core 7a is fixed to the lower inner wall of the pneumatic dynamic balancing device 7 through a variable damper.

[0025] The electromagnet A9 is electrically connected to the weighing sensor 6. The weighing sensor 6 outputs an electrical signal according to the weight of the input weight. The air pressure dynamic balancing device 7 then converts the electrical signal into an electromagnetic force of corresponding proportion to adjust the moving direction of the balancing iron core. The sealing roller 4 is an elastic sealing film that can ensure the sealing of the pressure-bearing sealed chamber 1a, allowing the dynamic coil 2 to move up and down relative to the pressure-bearing platform 1, while not affecting the vibration of the dynamic coil 2. The upper and lower sealed chambers are provided with a block 7b corresponding to the pipe B for preventing the test sealed chamber 5a from communicating with the pressure-bearing sealed chamber 1a. The block is welded and fixed to the inner wall of the air pressure dynamic balancing device 7 and is located between the pipes A and B. When the balancing iron core 7a reaches the limit position, the test sealed chamber 5a and the pressure sealed chamber 1a are also not connected to each other. Therefore, it is possible to prevent water vapor and foreign matter in the test sealed chamber 5a from entering the pressure sealed chamber 1a, thereby avoiding electromagnetic coil failure. The pressure-bearing sealed cavity 1a is provided with an electromagnet B8 fixed to the inner wall of the pressure-bearing sealed cavity 1a and a magnetic induction coil 3 corresponding to the electromagnet B8 and sleeved on the outside of the moving coil 2.

[0026] The pressure-bearing platform 1, moving coil 2, magnetic induction coil 3, sealing roller 4, comprehensive test box 5, weighing sensor 6, air pressure dynamic balancing device 7, balancing iron core 7a, block 7b, electromagnet B8, electromagnet A9, spring 11, variable damper 1, pipe A, pipe B, exhaust pipe C, vacuum pipe 10, and vacuum device of this embodiment all adopt existing products or structures well known to those skilled in the art, and the connections between them also adopt existing connection methods or control methods well known to those skilled in the art, and will not be introduced in detail here.

[0027] The working principle of this embodiment is as follows:

[0028] The comprehensive test box 5 is independently provided with a vacuum pipe, which is kept in working state under normal conditions, so that the test sealed chamber 5a is kept in a low-pressure environment;

[0029] Assume that the pressure in the test sealed chamber 5a is P1, where P1 is a low pressure known to those skilled in the art; the pressure in the pressure-bearing sealed chamber 1a is P2; the upper area of the moving coil 2 is S1, the lower area is S2; the weight of the load measured by the top load cell 6 is G; and the cross-sectional area of the balance core 7a is A1. To maintain high-frequency, small-amplitude vibration on the vibration table, the following conditions must be met:

[0030] Target condition: P1S1+G=P2S2

[0031] Prerequisite: P1A1+F=P2A1

[0032] Where F is the resultant force of electromagnetic force and damping force

[0033] Combining the two equations, we get:

[0034] In the formula, A1, P1, S1, and S2 are all known quantities, and corresponding F is generated according to different Gs. Before the vibration table works, when placing a heavy object, the existing placement method familiar to those skilled in the art is adopted, which is not described in detail here. If the moving coil 2 falls rapidly, the weighing sensor 6 outputs an electrical signal according to the input weight G of the heavy object, and the air pressure dynamic balancing device 7 converts the electrical signal into an electromagnetic force of the corresponding proportion. The specific conversion method and proportion adopt the existing conversion method and proportion familiar to those skilled in the art, which is not described in detail here. The balancing iron core 7a moves downward under the action of the combined force F of the electromagnetic force and the damping force generated by the spring and the variable damper. The pipeline A and the exhaust pipeline C are connected, the comprehensive test box 5 starts to be vacuumed, and the pressure of the test sealing chamber 5a decreases until the pressure of the test sealing chamber 5a is equal to that of the pressure-bearing sealing chamber 1a, and the vibration table reaches balance.

[0035] During the operation of the vibration table, if the pressure in the test seal chamber 5a is greater than the pressure in the pressure-bearing seal chamber 1a, that is, when P1S1 + G > P2S2, the pressure P1 in the test seal chamber 5a is too large and exceeds the pre-adjusted force of the spring and the variable damper. The pre-adjusted force is the pre-adjusted force of the spring and the variable damper when the balance iron core 7a blocks the exhaust pipe C when the vibration table reaches equilibrium, which is well-known to those skilled in the art. Then the balance iron core 7a moves downward, and the pipe A and the exhaust pipe C are connected. The comprehensive test chamber 5 starts to evacuate, and the pressure in the test seal chamber 5a decreases until the pressures in the test seal chamber 5a and the pressure-bearing seal chamber 1a are equal, and the vibration table reaches equilibrium. If the pressure in the test seal chamber 5a is less than the pressure in the pressure-bearing seal chamber 1a, that is, when P1S1 + G < P2S2, the pressure in the pressure-bearing table inner chamber 1a is too large and exceeds the pre-adjusted force of the spring and the variable damper. The pre-adjusted force is the pre-adjusted force of the spring and the variable damper when the balance iron core 7a blocks the exhaust pipe C when the vibration table reaches equilibrium, which is well-known to those skilled in the art. Acting on the balance iron core 7a, it moves upward. At this time, the pipe B and the exhaust pipe C are connected, and the pressure-bearing seal chamber 1a is evacuated. The pressure P2 in the pressure-bearing seal chamber 1a gradually decreases until the system reaches a new equilibrium. Repeating this process, the system maintains dynamic equilibrium throughout the process, and the moving coil 2 can maintain small-amplitude high-frequency vibration.

[0036] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims

1. Low pressure environment vibration test system dynamic center holding device, characterized in that: The invention comprises a pressure-bearing platform (1) and a comprehensive test box (5), wherein a moving coil (2) is provided in the pressure-bearing platform (1), and the upper part of the moving coil (2) extends into the comprehensive test box (5) through the moving coil through hole (1b) on the pressure-bearing platform (1), and a test sealing cavity (5a) is formed between the moving coil (2) and the comprehensive test box (5), and a sealing rolling film (4) for sealing the pressure-bearing platform (1) and the moving coil (2) is provided at the moving coil through hole (1b). A pressure sealing cavity (1a) is formed between the pressure-bearing platform (1), the moving coil (2), and the sealing rolling film (4), and a weighing sensor (6) for measuring the weight of a loaded object is installed at the top end of the moving coil (2) extending into the test sealing cavity (5a), and the weighing sensor (6) is electrically connected to an air pressure dynamic balance device (7). A balancing iron core (7a) is provided in the air pressure dynamic balancing device (7), an upper sealed cavity is formed between the upper end surface of the balancing iron core (7a) and the inner wall of the air pressure dynamic balancing device (7), a lower sealed cavity is formed between the lower end surface of the balancing iron core (7a) and the inner wall of the air pressure dynamic balancing device (7), the upper sealed cavity is connected to the test sealed cavity (5a) through a pipe A, and the lower sealed cavity is connected to the pressure-bearing sealed cavity (1a) through a pipe B, an exhaust pipe C is provided on the air pressure dynamic balancing device (7), the balancing iron core (7a) is connected to a spring and a variable damper capable of controlling the exhaust pipe C to be connected to the upper sealed cavity or the lower sealed cavity, the test sealed cavity (5a) is connected to a vacuum pipe, and the exhaust pipe C and the vacuum pipe are connected to a vacuum device.

2. The dynamic center holding device of the low-pressure environment vibration test system according to claim 1, characterized in that: The upper end of the balancing iron core (7a) is fixed to the electromagnet A (9) on the upper part of the pneumatic dynamic balancing device (7) via a spring, and the lower end of the balancing iron core (7a) is fixed to the lower inner wall of the pneumatic dynamic balancing device (7) via a variable damper.

3. The dynamic center holding device of the low-pressure environment vibration test system according to claim 2, characterized in that: The electromagnet A (9) is electrically connected to the weighing sensor (6).

4. The dynamic center holding device for a low-pressure environment vibration test system according to claim 1, characterized in that: The sealing rolling film (4) is an elastic sealing film.

5. The dynamic center holding device for the low-pressure environment vibration test system according to claim 1, characterized in that: Blocks corresponding to the pipeline B are provided in the upper sealing cavity and the lower sealing cavity and are used to prevent the test sealing cavity (5a) from communicating with the pressure-bearing sealing cavity (1a).

6. The dynamic center holding device for the low-pressure environment vibration test system according to claim 5, characterized in that: The stopper is welded and fixed to the inner wall of the air pressure dynamic balancing device (7) and is located between the pipe A and the pipe B.

7. The dynamic center holding device for a low-pressure environment vibration test system according to claim 1, characterized in that: The pressure-bearing sealed cavity (1a) is provided with an electromagnet B (8) fixed to the inner wall of the pressure-bearing sealed cavity (1a) and a magnetic induction coil (3) corresponding to the electromagnet B (8) and sleeved on the outside of the moving coil (2).

Images