Positive and negative pressure high and low temperature environment simulation test bench and its usage method

Abstract

The present invention discloses a positive and negative pressure high and low temperature environment simulation test bench and its usage method, which includes a cavity. A first heat and cold circulator and a temperature sensor are connected to the cavity. A cavity door and two pairs of interfaces are provided on the cavity. One pair of interfaces are respectively connected to pressure branch pipelines, and the other pair of interfaces are respectively connected to vacuum branch pipelines. A pressure heat exchanger is provided on the pressure branch pipeline, and a pressure on-off valve and an air compressor are provided on the pressure main pipeline. The cavity door is connected through a flange. The pressure heat exchanger and the vacuum heat exchanger are respectively connected to high and low temperature heat exchanger branch pipelines. A high and low temperature cavity door branch pipeline is connected at the sealing ring. The high and low temperature cavity door branch pipeline and the two high and low temperature heat exchanger branch pipelines are connected in parallel to the high and low temperature main pipeline, and the high and low temperature main pipeline is connected to a second heat and cold circulator. It solves the technical problem that currently, due to the respective requirements of the pressure and temperature environments, the equipment cannot be integrated into a set of systems, resulting in high costs and limited simulation environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of environmental simulation, and particularly relates to a positive and negative pressure high and low temperature environmental simulation test bench and a using method thereof. Background Art

[0002] With the development of environmental simulation test equipment and technology, in the process of practice and solving theoretical problems, relevant theories and methods of multiple disciplines (such as thermotics, mechanics, electricity, biology, medicine, and optics, etc.) and multiple technologies (such as refrigeration, vacuum, air conditioning, automatic control, metrology, etc.) have been absorbed, forming an independent technical theory system - environmental simulation technology. Environmental simulation technology is a new interdisciplinary technology, mainly studying the artificial reproduction technology of various natural environments and induced environments and the test technology under environmental simulation conditions.

[0003] At present, through research and development, people have respectively developed environmental simulation equipment for the fields of air pressure or temperature, including different system equipment for environmental simulation under high temperature with pressure, environmental simulation under high temperature in vacuum, environmental simulation under low temperature with pressure, and environmental simulation under low temperature in vacuum. The equipment is independent of each other, unable to simulate environments with different pressures and temperatures, unable to simulate different positive and negative pressure environments inside and outside workpieces, with limitations in simulation, and multiple sets of systems require high costs. Moreover, for each field of pressure, vacuum, high temperature, and low temperature, there are respective standard requirements. These requirements not only interfere with each other, but also have a great impact on pumps, valves, measuring instruments, and sealing forms. Therefore, integrating them into a set of systems requires solving the sealing problem and the accuracy problem of measuring instruments under different environments. Summary of the Invention

[0004] The present invention provides a positive and negative pressure high and low temperature environmental simulation test bench and a using method thereof, so as to solve the technical problems that currently, due to the respective requirements of pressure and temperature environments, the equipment cannot be integrated into a set of systems, resulting in high costs and limited simulation environments.

[0005] To achieve the above object, the present invention adopts the following technical solutions: a positive and negative pressure high and low temperature environment simulation test bench, including a cavity, a first heat and cold circulation machine and a temperature sensor are connected to the cavity; a cavity door and two pairs of interfaces are provided on the cavity, each pair of interfaces includes a cavity flange interface and a workpiece flange interface, and a workpiece bellows is provided at one end of the workpiece flange interface that penetrates into the cavity; one pair of interfaces are respectively connected with pressure branch pipelines, and the other pair of interfaces are respectively connected with vacuum branch pipelines; a pressure heat exchanger and a pressure on-off valve are respectively provided on the pressure branch pipelines from one end of the cavity, the two pressure branch pipelines converge into a pressure main pipeline, and a pressure on-off valve and an air compressor are provided on the pressure main pipeline from one end of the pressure branch pipeline; a vacuum heat exchanger, a vacuum on-off valve and a vacuum sensor are respectively provided on the vacuum branch pipelines from one end of the cavity, the two vacuum branch pipelines converge into a vacuum main pipeline, and a vacuum on-off valve and a vacuum pump are provided on the vacuum main pipeline from one end of the vacuum branch pipeline; the pressure on-off valve and the vacuum on-off valve are both positive and negative pressure universal safety valves; the cavity is made of stainless steel material, the cavity door is connected by a flange, and two seals separated inside and outside are provided at the flange connection of the cavity door, the inner ring uses a tetrafluoro gasket and the outer ring uses a vacuum seal; the pressure heat exchanger and the vacuum heat exchanger are respectively connected with high and low temperature heat exchanger branch pipelines, the seal is connected with a high and low temperature cavity door branch pipeline, the high and low temperature cavity door branch pipeline and the two high and low temperature heat exchanger branch pipelines are connected in parallel to the high and low temperature main pipeline, and the high and low temperature main pipeline is connected to the second heat and cold circulation machine.

[0006] By adopting the above technical solutions, the first temperature cycling machine can achieve the system operation of low temperature and high temperature inside the cavity, the air compressor can achieve the system operation of the pressure inside and outside the workpiece in the cavity, and the vacuum pump can achieve the system operation of the vacuum inside and outside the cavity. Therefore, it can simulate the combined environment of different vacuums and high pressures inside and outside the workpiece under high and low temperature fixation, expand the scope of simulation, save the cost of separately making different environment simulations, achieve the effect of multi-purpose use of one machine, and have significant progress. It overcomes the following difficulties. First, the ability of the cavity to withstand different environments. Stainless steel materials are used and two layers of sealing rings are set. The inner sealing ring bears partial sealing and isolates temperature, and the outer ring plays a role in vacuum sealing. Pressure sealing can be achieved through compression, so that the cavity can meet the environmental simulation of the combined environment of low temperature, high temperature, vacuum, and high pressure. Second, the pressure regulating valve, pressure flowmeter, vacuum sensor, vacuum regulating valve, each pipeline and valve, vacuum pump, and air compressor will be affected by the cavity temperature. By setting a heat exchanger, a second temperature cycling machine is connected to the heat exchanger to neutralize the temperature of the pressure heat exchanger and the vacuum heat exchanger, and the sensors, valves, pipe fittings, and equipment can work at normal temperature to meet the experimental requirements. Third, for the valves of the pressure pipeline and the vacuum pipeline, a positive and negative pressure universal safety valve (the applicable pressure range is between absolute pressure 1 Pa and 1.0 MPa. If this pressure range is exceeded, the sealing and pressure resistance of the system need to be redesigned) is used, which can work under both pressure conditions and vacuum conditions. Therefore, by operating the opening and closing of the pressure or vacuum pipeline valve, the environmental state switching between pressure and vacuum can be achieved.

[0007] Preferably, the pressure heat exchangers on the two pressure branch pipelines share one heat exchanger, and the vacuum heat exchangers on the two vacuum branch pipelines share one heat exchanger.

[0008] By adopting the above technical solutions, the structure is simple, resources are saved, and control is convenient.

[0009] Preferably, a pressure relief pipeline is connected between the pressure heat exchanger and the pressure regulating valve, and a pressure on-off valve is arranged on the pressure relief pipeline.

[0010] By adopting the above technical solutions, the purpose of setting the pressure relief pipeline is to release pressure first and then evacuate the vacuum when the cavity needs to be evacuated, so as to protect the pump valves in the negative pressure part.

[0011] Preferably, a vacuum gas supply pipeline is connected between the vacuum heat exchanger and the vacuum sensor, and a vacuum on-off valve is arranged on the vacuum gas supply pipeline.

[0012] By adopting the above technical solutions, the purpose of setting the vacuum gas supply pipeline is to supply gas first and then pressurize when the cavity needs to be pressurized, so as to protect the cavity and the pump valves. In addition, the vacuum regulating valve on the vacuum gas supply pipeline can control the pressure increase speed in the negative pressure state.

[0013] Preferably, a pressure flowmeter is provided at one end of the pressure main pipeline close to the pressure branch pipeline, and a pressure regulating valve is provided at one end of the pressure branch pipeline close to the pressure main pipeline.

[0014] By adopting the above technical solution, the system can adjust the flow rate and pressure of the pressure regulating valve according to the feedback data of the pressure flowmeter, and control the pressurization speed and the pressure relief speed.

[0015] Preferably, a vacuum regulating valve is provided at one end of the vacuum branch pipeline close to the vacuum main pipeline.

[0016] By adopting the above technical solution, the system can adjust the pressure of the vacuum regulating valve according to the feedback data of the vacuum sensor, and control the vacuum pumping speed.

[0017] A method of using the above positive and negative pressure high and low temperature environment simulation test bench. When simulating positive and negative pressures in a high temperature environment, start the high and low temperature cooling and heating cycle machine 1 to heat, giving the cavity a high temperature environment, start the high and low temperature cooling and heating cycle machine 2 to cool, giving the cavity door, the pressure heat exchanger and the vacuum heat exchanger neutralizing cooling. If positive pressure is required inside the workpiece, connect the workpiece to the corresponding bellows on the pressure branch pipeline, and externally give the positive pressure or vacuum environment outside the workpiece and inside the cavity through the cavity flange interface without a bellows. If negative pressure is required inside the workpiece, connect the workpiece to the corresponding bellows on the vacuum branch pipeline, and externally give the positive pressure or vacuum environment outside the workpiece and inside the cavity through the cavity flange interface without a bellows. When simulating positive and negative pressures in a low temperature environment, start the high and low temperature cooling and heating cycle machine 1 to cool, giving the cavity a low temperature environment, start the high and low temperature cooling and heating cycle machine 2 to heat, giving the cavity door, the pressure heat exchanger and the vacuum heat exchanger neutralizing cooling. If positive pressure is required inside the workpiece, connect the workpiece to the corresponding bellows on the pressure branch pipeline, and externally give the positive pressure or vacuum environment outside the workpiece and inside the cavity through the cavity flange interface without a bellows. If negative pressure is required inside the workpiece, connect the workpiece to the corresponding bellows on the vacuum branch pipeline, and externally give the positive pressure or vacuum environment outside the workpiece and inside the cavity through the cavity flange interface without a bellows.

[0018] The beneficial effects of the present invention are reflected in that the cold and hot circulation machine 1 can realize the system operation of low temperature and high temperature in the cavity, the air compressor realizes the system operation of the pressure inside and outside the workpiece in the cavity, and the vacuum pump realizes the system operation of the vacuum inside and outside the cavity. Therefore, it can simulate the combined environment of different vacuums and high pressures inside and outside the workpiece under fixed high and low temperatures, expand the scope of simulation, save the cost of separately making different environment simulations, achieve the effect of multi-purpose use of one machine, and have remarkable progress. It overcomes the following difficulties: First, the ability of the cavity to withstand different environments. Stainless steel material is used and two layers of sealing rings are set. The inner sealing ring bears part of the sealing and isolates the temperature, and the outer ring plays a role in vacuum sealing. The pressure sealing can be achieved by pressing, so that the cavity can meet the environment simulation of the combined environment of low temperature, high temperature, vacuum and high pressure; Second, the pressure regulating valve, pressure flowmeter, vacuum sensor, vacuum regulating valve, each pipeline and valve, vacuum pump and air compressor will be affected by the cavity temperature. By setting a heat exchanger, the cold and hot circulation machine 2 is connected to the heat exchanger to neutralize the temperature of the pressure heat exchanger and the vacuum heat exchanger, and the sensors, valves, pipe fittings and equipment can work at normal temperature to meet the experimental requirements; Third, for the valves of the pressure pipeline and the vacuum pipeline, a positive and negative pressure universal safety valve is used (the applicable pressure range is between 1 Pa and 1.0 MPa in absolute pressure. If this pressure range is exceeded, the sealing and pressure resistance of the system need to be redesigned), which can work under both pressure conditions and vacuum conditions. Therefore, by operating the opening and closing of the pressure or vacuum pipeline valve, the environmental state switching between pressure and vacuum can be realized.

[0019] Other features and advantages of the present invention will be described in the following specification, and will be partially obvious from the specification, or will be understood by implementing the present invention; the main object and other advantages of the present invention can be achieved and obtained through the solutions specifically pointed out in the specification. Brief Description of the Drawings

[0020] Figure 1 is a schematic diagram of the pipeline connection structure of the embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of the structure of the cavity connection of the present invention.

[0022] Reference numerals: 1, cavity; 2, first hot and cold circulation machine; 3, temperature sensor; 4, cavity door; 5, cavity flange interface; 6, workpiece flange interface; 7, workpiece bellows; 8, pressure branch pipeline; 9, vacuum branch pipeline; 10, pressure heat exchanger; 11, pressure on-off valve; 12, pressure main pipeline; 13, air compressor; 14, vacuum heat exchanger; 15, vacuum on-off valve; 16, vacuum sensor; 17, vacuum main pipeline; 18, vacuum pump; 19, inner ring; 20, outer ring; 21, high and low temperature heat exchanger branch pipeline; 22, high and low temperature cavity door branch pipeline; 23, high and low temperature main pipeline; 24, second hot and cold circulation machine; 25, pressure relief pipeline; 26, vacuum gas supply pipeline; 27, pressure flowmeter; 28, pressure regulating valve; 29, vacuum regulating valve. Detailed implementation mode

[0023] The technical solution of the present invention will be described in detail below through embodiments. The following embodiments are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, rather than being construed as a limitation to the technical solution of the present invention.

[0024] Such as Figure 1 And Figure 2, a positive and negative pressure high and low temperature environment simulation test bench, including a cavity 1. A first heat and cold circulator 2 and a temperature sensor 3 are connected to the cavity 1, and the connection is a conventional connection, which will not be elaborated here. A cavity door 4 and two pairs of interfaces are provided on the cavity 1. Each pair of interfaces includes a cavity flange interface 5 and a workpiece flange interface 6. One end of the workpiece flange interface 6 passing through the cavity 1 is provided with a workpiece bellows 7. One pair of interfaces are respectively connected to a pressure branch pipeline 8, and the other pair of interfaces are respectively connected to a vacuum branch pipeline 9. A pressure heat exchanger 10 and a pressure on-off valve 11 are respectively provided on the pressure branch pipeline 8 from one end of the cavity 1. The two pressure branch pipelines 8 converge into a pressure main pipeline 12. A pressure on-off valve 11 and an air compressor 13 from one end of the pressure branch pipeline 8 are provided on the pressure main pipeline 12. A vacuum heat exchanger 14, a vacuum on-off valve 15, and a vacuum sensor 16 are respectively provided on the vacuum branch pipeline 9 from one end of the cavity 1. The two vacuum branch pipelines 9 converge into a vacuum main pipeline 17. A vacuum on-off valve 15 and a vacuum pump 18 from one end of the vacuum branch pipeline 9 are provided on the vacuum main pipeline 17. The pressure on-off valve 11 and the vacuum on-off valve 15 are both positive and negative pressure universal safety valves. The cavity 1 is made of stainless steel material. The cavity door 4 is connected by a flange. Two seals separated inside and outside are provided at the flange connection on the cavity door 4. The inner ring 19 uses a tetrafluoro gasket (or other heat-insulating gaskets that do not affect the vacuum), and the outer ring 20 uses a vacuum gasket. The pressure heat exchanger 10 and the vacuum heat exchanger 14 are respectively connected to a high and low temperature heat exchanger branch pipeline 21. A high and low temperature cavity door branch pipeline 22 is connected to the seal. The high and low temperature cavity door branch pipeline 22 and the two high and low temperature heat exchanger branch pipelines 21 are connected in parallel to a high and low temperature main pipeline 23. The high and low temperature main pipeline 23 is connected to a second heat and cold circulator 24. The high and low temperature cavity door branch pipeline 22, the two high and low temperature heat exchanger branch pipelines 21, and the high and low temperature main pipeline 23 are all circulating double pipelines.

[0025] The thermal cycling machine 2 can achieve the system operation of low temperature and high temperature inside the cavity 1. The air compressor 13 realizes the system operation of the pressure inside and outside the workpiece in the cavity 1, and the vacuum pump 18 realizes the system operation of the vacuum inside and outside the cavity 1. Therefore, it can simulate the combined environment of different vacuums and high pressures inside and outside the workpiece under high and low temperature fixation, saving the cost of separately manufacturing different environment simulations and achieving the effect of multi-purpose use of one machine, showing significant progress. It overcomes the following difficulties. First, the ability of the cavity 1 to withstand different environments. Stainless steel material is used and two layers of sealing rings are set. The inner ring 21 sealing ring bears part of the sealing and isolates the temperature, and the outer ring 20 serves as a vacuum seal. The pressure seal can be achieved by pressing, so that the cavity 1 can meet the environmental simulation of the combined environment of low temperature, high temperature, vacuum and high pressure. Second, the pressure regulating valve 28, the pressure flowmeter 27, the vacuum sensor 16, the vacuum regulating valve 28, each pipeline and valve, the vacuum pump 18, and the air compressor 13 will be affected by the temperature of the cavity 1. By setting a heat exchanger, the heat exchanger is connected to the thermal cycling machine 24 to neutralize the temperatures of the pressure heat exchanger 10 and the vacuum heat exchanger 14, so that the sensors, valves, pipe fittings and equipment can work at normal temperature to meet the experimental requirements. Third, for the valves of the pressure pipeline and the vacuum pipeline, a positive and negative pressure universal safety valve is adopted (the applicable pressure range is between 1 Pa and 1.0 MPa in absolute pressure. If this pressure range is exceeded, the sealing and pressure resistance of the system need to be redesigned), which can work under both pressure conditions and vacuum conditions. Therefore, by operating the opening and closing of the pressure or vacuum pipeline valve, the environmental state switching between pressure and vacuum can be achieved.

[0026] The pressure heat exchangers 10 on the two pressure branch pipelines 8 share one heat exchanger, and the vacuum heat exchangers 14 on the two vacuum branch pipelines 9 share one heat exchanger, with simple structure, resource saving and convenient control.

[0027] A pressure relief pipeline 25 is connected between the pressure heat exchanger 10 and the pressure regulating valve 28, and a pressure on-off valve 11 is arranged on the pressure relief pipeline 25. The purpose of setting the pressure relief pipeline 25 is to release the pressure first and then evacuate the vacuum when the cavity 1 needs to be evacuated, protecting the pump valves in the negative pressure part. A vacuum gas supply pipeline 26 is connected between the vacuum heat exchanger 14 and the vacuum sensor 16, and a vacuum on-off valve 15 is arranged on the vacuum gas supply pipeline 26. The purpose of setting the vacuum gas supply pipeline 26 is to supply gas first and then pressurize when the cavity 1 needs to be pressurized, protecting the cavity and the pump valves. In addition, the vacuum regulating valve 29 on the vacuum gas supply pipeline 26 can control the pressure increase speed in the negative pressure state.

[0028] A pressure flowmeter 27 is provided at one end of the pressure main pipeline 12 close to the pressure branch pipeline 8. A pressure regulating valve 28 is provided at one end of the pressure branch pipeline 8 close to the pressure main pipeline 12. The pressure regulating valve 28 system can adjust the flow rate and pressure of the pressure regulating valve 28 according to the feedback data of the pressure flowmeter 27, and control the pressurization speed and the pressure relief speed.

[0029] A vacuum regulating valve 29 is provided at one end of the vacuum branch pipeline 9 close to the vacuum main pipeline 17. The vacuum regulating valve 29 system can adjust the pressure of the vacuum regulating valve 29 according to the feedback data of the vacuum sensor 16, and control the vacuum pumping speed.

[0030] The specific usage method is as follows. When simulating positive and negative pressures in a high-temperature environment, start the high-low temperature cooling and heating cycle machine 2 to heat, and give the cavity 1 a high-temperature environment. Start the high-low temperature cooling and heating cycle machine 24 to cool, and give the cavity door 4, the pressure heat exchanger 10, and the vacuum heat exchanger 14 neutralization and cooling. If positive pressure is required inside the workpiece, connect the workpiece to the bellows corresponding to the pressure branch pipeline 8, and externally give the positive pressure or vacuum environment inside the cavity 1 outside the workpiece through the cavity flange interface 5 without a bellows. If negative pressure is required inside the workpiece, connect the workpiece to the bellows corresponding to the vacuum branch pipeline 9, and externally give the positive pressure or vacuum environment inside the cavity 1 outside the workpiece through the cavity flange interface 5 without a bellows. When simulating positive and negative pressures in a low-temperature environment, start the high-low temperature cooling and heating cycle machine 2 to cool, and give the cavity 1 a low-temperature environment. Start the high-low temperature cooling and heating cycle machine 24 to heat, and give the cavity door 4, the pressure heat exchanger 10, and the vacuum heat exchanger 14 neutralization and cooling. If positive pressure is required inside the workpiece, connect the workpiece to the bellows corresponding to the pressure branch pipeline 8, and externally give the positive pressure or vacuum environment inside the cavity 1 outside the workpiece through the cavity flange interface 5 without a bellows. If negative pressure is required inside the workpiece, connect the workpiece to the bellows corresponding to the vacuum branch pipeline 9, and externally give the positive pressure or vacuum environment inside the cavity 1 outside the workpiece through the cavity flange interface 5 without a bellows.

[0031] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. Positive and negative pressure high and low temperature environment simulation test bench, Characterized in that: It includes a cavity (1), to which a first hot and cold circulator (2) and a temperature sensor (3) are connected; a cavity door (4) and two pairs of interfaces are provided on the cavity (1), and each pair of interfaces includes a cavity flange interface (5) and a workpiece flange interface (6). A workpiece bellows (7) is provided at one end of the workpiece flange interface (6) that penetrates into the cavity (1); one pair of interfaces are respectively connected to a pressure branch pipeline (8), and the other pair of interfaces are respectively connected to a vacuum branch pipeline (9); a pressure heat exchanger (10) and a pressure on-off valve (11) are respectively provided on the pressure branch pipeline (8) at one end of the cavity (1). The two pressure branch pipelines (8) converge into a pressure main pipeline (12), and a pressure on-off valve (11) and an air compressor (13) from one end of the pressure branch pipeline (8) are provided on the pressure main pipeline (12); a vacuum heat exchanger (14), a vacuum on-off valve (15), and a vacuum sensor (16) are respectively provided on the vacuum branch pipeline (9) at one end of the cavity (1). The two vacuum branch pipelines (9) converge into a vacuum main pipeline (17), and a vacuum on-off valve (15) and a vacuum pump (18) from one end of the vacuum branch pipeline (9) are provided on the vacuum main pipeline (17); both the pressure on-off valve (11) and the vacuum on-off valve (15) are positive and negative pressure universal safety valves; the cavity (1) is made of stainless steel material, the cavity door (4) is connected by a flange, and two seals separated inside and outside are provided at the flange connection on the cavity door (4). The inner ring (19) uses a PTFE gasket, and the outer ring (20) uses a vacuum gasket; the pressure heat exchanger (10) and the vacuum heat exchanger (14) are respectively connected to high and low temperature heat exchanger branch pipelines (21), and the seal is connected to a high and low temperature cavity door branch pipeline (22). The high and low temperature cavity door branch pipeline (22) and the two high and low temperature heat exchanger branch pipelines (21) are connected in parallel to a high and low temperature main pipeline (23), and the high and low temperature main pipeline (23) is connected to a second hot and cold circulator (24). The usage method is as follows. When simulating positive and negative pressures in a high temperature environment, start the first high and low temperature hot and cold circulator (2) to heat, provide a high temperature environment for the cavity (1), start the second hot and cold circulator (24) to cool, and provide neutralization and cooling for the cavity door (4), the pressure heat exchanger (10), and the vacuum heat exchanger (14). If positive pressure is required inside the workpiece, connect the workpiece to the corresponding bellows on the pressure branch pipeline (8), and provide positive pressure or vacuum environment outside the workpiece and inside the cavity (1) through the cavity flange interface (5) without a bellows outside. If negative pressure is required inside the workpiece, connect the workpiece to the corresponding bellows on the vacuum branch pipeline (9), and provide positive pressure or vacuum environment outside the workpiece and inside the cavity (1) through the cavity flange interface (5) without a bellows outside;When simulating positive and negative pressures under low-temperature environments, start the high-low temperature cooling and heating cycle machine one (2) for refrigeration to provide a low-temperature environment for the cavity (1), and start the high-low temperature cooling and heating cycle machine two (24) for heating to neutralize and cool the cavity door (4), the pressure heat exchanger (10), and the vacuum heat exchanger (14). If positive pressure is required inside the workpiece, connect the workpiece to the bellows corresponding to the pressure branch pipeline (8), and externally provide a positive pressure or vacuum environment outside the workpiece and inside the cavity (1) through the cavity flange interface (5) without a bellows. If negative pressure is required inside the workpiece, connect the workpiece to the bellows corresponding to the vacuum branch pipeline (9), and externally provide a positive pressure or vacuum environment outside the workpiece and inside the cavity (1) through the cavity flange interface (5) without a bellows.; 2. The positive and negative pressure high and low temperature environment simulation test bench according to claim 1, Characterized in that: The pressure heat exchangers (10) on the two pressure branch pipelines (8) share one heat exchanger, and the vacuum heat exchangers (14) on the two vacuum branch pipelines (9) share one heat exchanger.

3. The positive and negative pressure high and low temperature environment simulation test bench according to claim 1, Characterized in that: A pressure relief pipeline (25) is connected between the pressure heat exchanger (10) and the pressure regulating valve (28), and a pressure on-off valve (11) is arranged on the pressure relief pipeline (25).

4. The positive and negative pressure high and low temperature environment simulation test bench according to claim 1, Characterized in that: A vacuum gas supply pipeline (26) is connected between the vacuum heat exchanger (14) and the vacuum sensor (16), and a vacuum on-off valve (15) is arranged on the vacuum gas supply pipeline (26).

5. The positive and negative pressure high and low temperature environment simulation test bench according to claim 1, Characterized in that: A pressure flowmeter (27) is arranged at one end of the pressure main pipeline (12) close to the pressure branch pipeline (8), and a pressure regulating valve (28) is arranged at one end of the pressure branch pipeline (8) close to the pressure main pipeline (12).

6. The positive and negative pressure high and low temperature environment simulation test bench according to claim 1, Characterized in that: A vacuum regulating valve (29) is arranged at one end of the vacuum branch pipeline (9) close to the vacuum main pipeline (17).

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