Vacuum Friction Testing Machine Atmosphere Control Device and Method

Abstract

The present invention relates to an atmosphere control device for a vacuum friction tester. The device comprises at least two compressed air circuits, a collecting air circuit, a first air circuit, a second air circuit, a liquid container, a gas mixing container, a connecting pipe, a third air circuit, a first humidity sensor, a first branch circuit, a second branch circuit, a third branch circuit, a fourth branch circuit, a mechanical pump, a gas concentration sensor, a second humidity sensor, an ionization vacuum gauge, a first thermal conductivity vacuum gauge, a vacuum partial pressure gauge, a first baffle valve, a second baffle valve, a turbomolecular pump, a third baffle valve, a plug valve, and a second thermal conductivity vacuum gauge. The device is capable of controlling the humidity of the air atmosphere, the vacuum level of different single gases, the vacuum level of volatile liquids with different saturated vapor pressures, and atmospheric pressure mixing and vacuum level control of mixed gases of different proportions, thereby facilitating testing under different working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of test atmosphere control, in particular to a vacuum friction testing machine atmosphere control device and method. Background Art

[0002] Solid lubrication design is an important research topic in the field of mechanical engineering tribology, and exploring the influence of environmental atmosphere on the friction interface has important basic scientific and engineering application significance for revealing the mechanism of solid self-lubrication and improving the robustness of self-lubrication. In experimental research, in order to simulate special application conditions, it is necessary to control different atmospheres, including: humidity control of air atmosphere, vacuum control of different single gases, vacuum control of volatile liquids with different saturated vapor pressures, and normal pressure mixing and vacuum control of mixed gases of different proportions. For example, it is necessary to verify the self-lubrication robustness of solid friction pairs in different climatic environments through variable humidity friction experiments; it is necessary to verify the self-lubrication robustness of solid friction pairs in different climatic environments through 10 -5 Pa~10 5 The vacuum degree of Pa simulates the different flight altitudes of spacecraft; it is necessary to pass 5×10 2 Pa~7×10 2 Pa partial pressure of CO 2 Atmosphere simulation of deep space probe Mars working conditions, etc. This type of research is of great significance to solid lubrication in various fields such as mechanical engineering and aerospace.

[0003] However, there are currently no testing machine products or public design solutions that can simultaneously achieve the control of the above-mentioned multiple different atmospheres, which makes it inconvenient to conduct experiments under different working conditions. Summary of the Invention

[0004] Based on this, it is necessary to provide a vacuum friction testing machine atmosphere control device and method to address the problem that there are currently no testing machine products and public design solutions that can simultaneously achieve the control of the above-mentioned multiple different atmospheres, which makes it inconvenient to conduct experiments under different working conditions.

[0005] One embodiment of the present application provides an atmosphere control device for a vacuum friction testing machine, comprising: at least two compressed air circuits and a collection air circuit, wherein an input end of each compressed air circuit is connected to a compressed gas source, and output ends of the at least two compressed air circuits are commonly connected to an input end of the collection air circuit, and each compressed air circuit is provided with a pressure reducing valve, a barometer, and a throttle valve arranged in sequence along a gas flow direction within the compressed air circuit;

[0006] The vacuum friction tester atmosphere control device further includes: a first gas path, a second gas path, a liquid container, a gas mixing container, a connecting pipe, a third gas path, and a first humidity sensor;

[0007] A first gas path and a second gas path are provided between the pressure reducing valve and the throttle valve provided on one of the compressed gas paths. One end of the first gas path is connected to the compressed gas path, and the other end extends into the liquid container. One end of the second gas path is connected to the compressed gas path, and the other end extends into the gas mixing container. A fifth throttle valve is provided on the first gas path, and a sixth throttle valve is provided on the second gas path. The liquid container and the gas mixing container are connected via a connecting pipe.

[0008] The input end of the third gas circuit extends into the gas mixing container, the output end of the third gas circuit is connected to the input end of the aggregate gas circuit, and a seventh throttle valve is provided on the third gas circuit; the first humidity sensor is provided on the third gas circuit, and is located upstream of the seventh throttle valve along the direction of gas flow in the third gas circuit;

[0009] The vacuum friction tester atmosphere control device further comprises: a first branch, a second branch, a third branch, a fourth branch and a mechanical pump;

[0010] The input end of the first branch is connected to the output end of the aggregate gas circuit, and a first ball valve is provided on the first branch. The output end of the first branch is used to connect to a gas recovery container or to be vented to the atmosphere; the input end of the second branch is connected to the output end of the aggregate gas circuit, and the output end of the second branch is used to be connected to the vacuum chamber. A second ball valve and an eighth throttle valve are provided on the second branch, and along the direction of gas flow in the second branch, the second ball valve is located upstream of the eighth throttle valve; one end of the third branch is connected to the output end of the aggregate gas circuit, and the other end is used to be connected to the vacuum chamber, and a vacuum fine-tuning valve is provided on the third branch; the input end of the fourth branch is connected to the output end of the aggregate gas circuit, and the output end of the fourth branch is connected to a mechanical pump, and a third ball valve is provided on the fourth branch; the exhaust port of the mechanical pump is used to connect to a gas recovery container or to be vented to the atmosphere;

[0011] The vacuum friction tester atmosphere control device further comprises: a gas concentration sensor, a second humidity sensor, an ionization vacuum gauge, a first thermal conductivity vacuum gauge, and a vacuum partial pressure gauge for connection to the vacuum chamber;

[0012] The atmosphere control device of the vacuum friction testing machine also includes: a first baffle valve, a second baffle valve, a turbomolecular pump, a third baffle valve, a plug valve, and a second thermal conductivity vacuum gauge; one end of the first baffle valve is used to connect to the vacuum chamber, and the other end is connected to the mechanical pump; one end of the second baffle valve is used to connect to the vacuum chamber, and the other end is connected to the atmosphere; one end of the plug valve is used to connect to the vacuum chamber, and the other end is connected to the turbomolecular pump; the turbomolecular pump is connected to the mechanical pump through the third baffle valve; a second thermal conductivity vacuum gauge is provided on the fourth branch, and along the direction of gas flow in the fourth branch, the second thermal conductivity vacuum gauge is provided upstream of the mechanical pump.

[0013] An embodiment of the present application provides a method for controlling the atmosphere of a vacuum friction tester, which is implemented using any of the above-mentioned vacuum friction tester atmosphere control devices, and is used to control the humidity of the air atmosphere. The method for controlling the atmosphere of a vacuum friction tester includes the following steps:

[0014] S110: Selecting a compressed air source as the compressed gas source connected to the compressed gas circuit connected to the first gas circuit and the second gas circuit, and placing deionized water in the liquid container;

[0015] S120: Turn on the first thermal conductivity vacuum gauge, the mechanical pump, and the first baffle valve, and after the vacuum chamber is evacuated to a medium vacuum, turn off the first thermal conductivity vacuum gauge, the mechanical pump, and the first baffle valve;

[0016] S131: Turn on the first humidity sensor and the first ball valve, and fully open the seventh throttle valve;

[0017] S132: Open and adjust the pressure reducing valve on the compressed air circuit connected to the first air circuit and the second air circuit so that the pressure gauge on the compressed air circuit reads 0.1 MPa to 0.2 MPa;

[0018] S133: Opening and adjusting the fifth throttle valve and the sixth throttle valve so that the reading of the first humidity sensor reaches the humidity target value;

[0019] S140: Opening the first thermal conductivity vacuum gauge, the second ball valve, and the eighth throttle valve until the reading of the first thermal conductivity vacuum gauge reaches atmospheric pressure, then closing the first ball valve and opening the second baffle valve;

[0020] S151: Turn on the second humidity sensor;

[0021] S152: adjusting the opening and closing degrees of the fifth throttle valve and the sixth throttle valve according to the difference between the humidity target value and the reading of the second humidity sensor so that the change in the reading of the first humidity sensor is equal to an iteration value;

[0022] S153: Repeat step S152 until the reading of the second humidity sensor reaches the humidity target value.

[0023] An embodiment of the present application provides a method for controlling the atmosphere of a vacuum friction tester, which is implemented using any of the above-mentioned vacuum friction tester atmosphere control devices, and is used to control the vacuum degree of different single gases. The method for controlling the atmosphere of a vacuum friction tester includes the following steps:

[0024] S211: selecting any compressed gas circuit, and connecting an input end of the selected compressed gas circuit to a compressed gas source, wherein a single gas to be introduced into the vacuum chamber is used as the compressed gas in the compressed gas source;

[0025] S212: Open and adjust the pressure reducing valve on the selected compressed air line so that the pressure gauge on the compressed air line reads 0.1 MPa to 0.2 MPa;

[0026] S220: Turn on the first thermal conductivity vacuum gauge, the mechanical pump, the first baffle valve, the second thermal conductivity vacuum gauge, and the third ball valve, so that the readings of the first thermal conductivity vacuum gauge and the second thermal conductivity vacuum gauge are both medium vacuum;

[0027] S230: Close the mechanical pump, the first baffle valve and the third ball valve, and open the throttle valve, the second ball valve and the eighth throttle valve on the selected compressed air path to inflate the vacuum chamber to a vacuum degree of 10 4 Pa magnitude;

[0028] S240: Repeat steps S220 and S230 at least three times, then execute step S220 again, and then close the third ball valve;

[0029] S250: Introducing compressed gas from the selected compressed gas circuit into the vacuum chamber to maintain the vacuum degree in the vacuum chamber at a target vacuum degree.

[0030] In one embodiment, the target vacuum degree is 10 5 Pa~10 3 Pa, step S250 includes:

[0031] S2511: Turn off the mechanical pump and the first flapper valve, and keep the first thermal conductivity vacuum gauge open;

[0032] S2512: Open the throttle valve, the second ball valve and the eighth throttle valve on the selected compressed air line until the reading of the first thermal conductivity vacuum gauge reaches the target vacuum degree, and then close the second ball valve.

[0033] In one embodiment, the target vacuum degree is 10 3 Pa~10 1 Pa, step S250 includes:

[0034] S2521: Keep the first flapper valve, the mechanical pump, and the first thermal conductivity vacuum gauge open;

[0035] S2522: Fully open the throttle valve on the selected compressed air line, open the second ball valve, open and adjust the eighth throttle valve until the vacuum degree in the vacuum chamber is dynamically balanced at the target vacuum degree.

[0036] In one embodiment, the target vacuum degree is 10 1 Pa~10 -1 Pa, step S250 includes:

[0037] S2531: Close the first baffle valve, keep the mechanical pump and the first thermal conductivity vacuum gauge open, open the third baffle valve, the plug valve, the turbomolecular pump, and the ionization vacuum gauge to evacuate the vacuum chamber to a vacuum degree of 10 -1 Below Pa;

[0038] S2532: Fully open the throttle valve on the selected compressed air circuit, open and adjust the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches a dynamic balance at the target vacuum degree.

[0039] In one embodiment, the target vacuum degree is 10 -1 Pa~10 -3 Pa, step S250 includes:

[0040] S2541: Close the first damper valve, wrap a heating tape around the gas path where the mechanical pump, the third damper valve, the gate valve, and the turbomolecular pump are located, and around the vacuum chamber, and heat the heating tape to above 120° C. In this heated state, keep the mechanical pump, the third damper valve, the gate valve, and the turbomolecular pump open and running continuously for more than 48 hours;

[0041] S2542: Keep the mechanical pump, the third flapper valve, the plug valve, the turbomolecular pump, and the first thermal conductivity vacuum gauge open, fully open the throttle valve on the selected compressed gas line, and open and adjust the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches dynamic equilibrium at the target vacuum degree;

[0042] S2543: Turn on the vacuum pressure gauge and record the composition and proportion of the impurity gas in the vacuum chamber according to the reading of the vacuum pressure gauge.

[0043] An embodiment of the present application provides a method for controlling the atmosphere of a vacuum friction tester, which is implemented using any of the above-mentioned vacuum friction tester atmosphere control devices, and is used to control the vacuum degree of volatile liquids with different saturated vapor pressures. The method comprises the following steps:

[0044] S310: placing a volatile liquid in a liquid container;

[0045] S320: Open the second thermal conductivity vacuum gauge, the mechanical pump, the third ball valve, and the seventh throttle valve to allow the mechanical pump to extract the gas generated by the volatile liquid. When the reading of the second thermal conductivity vacuum gauge stabilizes, close the third ball valve.

[0046] S330: Turn on the first thermal conductivity vacuum gauge, the mechanical pump, and the first baffle valve to evacuate the vacuum chamber to a medium vacuum;

[0047] S340: Close the first baffle valve, open the third baffle valve, the plug valve, the turbomolecular pump and the ionization vacuum gauge to evacuate the vacuum chamber to a vacuum degree of 10-1 Below Pa;

[0048] S350: Open the second ball valve and the eighth throttle valve. When the reading of the first thermal conductivity vacuum gauge rises to 10 1 When the pressure is above 0.05 Pa, close the eighth throttle valve until the reading of the ionization vacuum gauge is 10 -1 Below Pa.

[0049] S360: Repeat step S350 at least three times.

[0050] S370: introducing gas generated by volatilization of the volatile liquid into the vacuum chamber to maintain the vacuum degree in the vacuum chamber at a target vacuum degree.

[0051] In one embodiment, the saturated vapor pressure of the volatile liquid is 10 3 Above, the target vacuum degree is the saturated vapor pressure of the volatile liquid ~10 3 Pa, step S370 includes:

[0052] S3711: Close the third flapper valve, the plug valve, the turbomolecular pump, and the mechanical pump, and keep the first thermal conductivity vacuum gauge open;

[0053] S3712: Open the seventh throttle valve, the second ball valve, and the eighth throttle valve until the reading of the first thermal conductivity vacuum gauge reaches the target vacuum degree, and then close the second ball valve.

[0054] In one embodiment, the saturated vapor pressure of the volatile liquid is 10 1 Above, the target vacuum degree is 10 3 Pa~10 1 Pa, step S370 includes:

[0055] S3721: Open the first flapper valve, keep the mechanical pump and the first thermal conductivity vacuum gauge open, and close the turbomolecular pump, the gate valve, and the third flapper valve;

[0056] S3722: Open the seventh throttle valve and the second ball valve; open and adjust the eighth throttle valve until the vacuum degree in the vacuum chamber is dynamically balanced at the target vacuum degree.

[0057] In one embodiment, the saturated vapor pressure of the volatile liquid is 10 -1 Above, the target vacuum degree is 10 1 Pa~10 - 1 Pa, step S370 includes:

[0058] S3731: Keep the mechanical pump, the third flapper valve, the plug valve, the turbomolecular pump, and the first thermal conductivity vacuum gauge open;

[0059] S3732: Open the seventh throttle valve, open and adjust the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches a dynamic balance at the target vacuum degree.

[0060] In one embodiment, the saturated vapor pressure of the volatile liquid is 10 -3 Above, the target vacuum degree is 10 -1 Pa~10 - 3 Pa, step S370 includes:

[0061] S3741: Wrap heating tape around the gas path where the mechanical pump, the third damper valve, the gate valve, and the turbomolecular pump are located, and around the vacuum chamber, and heat the heating tape to above 120° C. In this heated state, keep the mechanical pump, the third damper valve, the gate valve, and the turbomolecular pump open and running continuously for at least 48 hours.

[0062] S3742: Keep the mechanical pump, the third flapper valve, the plug valve, the turbomolecular pump, and the first thermal conductivity vacuum gauge open, open the seventh throttle valve, and open and adjust the vacuum fine-tuning valve until the vacuum level in the vacuum chamber reaches dynamic equilibrium at the target vacuum level.

[0063] S3743: Turn on the vacuum pressure gauge and record the composition and proportion of the impurity gas in the vacuum chamber according to the reading of the vacuum pressure gauge.

[0064] An embodiment of the present application provides a method for controlling the atmosphere of a vacuum friction tester, which is implemented using any of the above-mentioned vacuum friction tester atmosphere control devices, and is used to control the mixing of mixed gases of different proportions at normal pressure. The method comprises the following steps:

[0065] S411: Selecting a plurality of compressed gas circuits, wherein the plurality of compressed gas circuits correspond one-to-one to the types of gases to be mixed, and selecting a compressed gas source of the corresponding type as a compressed gas source connected to the selected compressed gas circuits;

[0066] S412: Open and adjust the pressure reducing valves on the selected plurality of compressed air lines so that the pressure gauges on the plurality of compressed air lines read 0.1 MPa to 0.2 MPa;

[0067] S420: Turn on the first thermal conductivity vacuum gauge, the second thermal conductivity vacuum gauge, the mechanical pump, the first baffle valve, and the third ball valve, and after the first thermal conductivity vacuum gauge indicates a medium vacuum, close the first baffle valve.

[0068] S430 includes: S431: opening the throttle valve on one of the selected compressed air lines until the reading of the second thermal conductivity vacuum gauge rises to 10 4When the pressure reaches the Pa level, close the throttle valve until the reading of the second thermal conductivity vacuum gauge drops to 10 2 Pa below; S432: After repeating step S431 at least three times, close the third ball valve;

[0069] S440: Opening the throttle valve, the second ball valve, and the eighth throttle valve on one of the compressed gas lines in step S430 until the reading of the first thermal conductivity vacuum gauge rises to the partial pressure of the gas type corresponding to the compressed gas line, and then closing the second ball valve, the eighth throttle valve, and the throttle valve;

[0070] S450: executing step S430 and step S440 multiple times, wherein the number of times step S430 and step S440 are executed is equal to the number of the selected multiple compressed air circuits, and the compressed air circuit opened each time step S430 and step S440 are executed is different from one another;

[0071] S461: Turn on the gas concentration sensor. If the proportion of a certain gas is insufficient, repeat step S430, and select the compressed gas path corresponding to the certain gas in step S430;

[0072] S462: Opening the throttle valve, the second ball valve, and the eighth throttle valve on the compressed gas path corresponding to the certain gas to fill the vacuum chamber with the certain gas until the gas concentration sensor indicates that the proportion of the certain gas reaches a target proportion value, and then closing the second ball valve, the eighth throttle valve, and the throttle valve;

[0073] S463: Open the first ball valve and the vacuum fine-tuning valve until the reading of the first thermal conductivity vacuum gauge drops to normal pressure, and then close the first ball valve and the vacuum fine-tuning valve.

[0074] An embodiment of the present application provides a method for controlling the atmosphere of a vacuum friction tester, which is implemented using any of the above-mentioned vacuum friction tester atmosphere control devices, and is used to control the vacuum degree of mixed gases with different proportions. The method comprises the following steps:

[0075] S510: Turn on the first thermal conductivity vacuum gauge, the mechanical pump, the first baffle valve, and the third ball valve, so that the first thermal conductivity vacuum gauge shows a medium vacuum, and then turn on the third ball valve and the first baffle valve.

[0076] S520: Open the third baffle valve, the plug valve, the turbomolecular pump, and the ionization vacuum gauge to evacuate the vacuum chamber to a vacuum degree of 10 -1 Below Pa;

[0077] S531: Selecting a plurality of compressed gas circuits, wherein the plurality of compressed gas circuits correspond one-to-one to the types of gases to be mixed, and selecting a compressed gas source of the corresponding type as the compressed gas source connected to the selected compressed gas circuits;

[0078] S532: Open and adjust the pressure reducing valves on the selected plurality of compressed air lines so that the pressure gauges on the plurality of compressed air lines read 0.1 MPa to 0.2 MPa;

[0079] S533: Opening the first ball valve and the throttle valves on the selected plurality of compressed air paths, so that the various types of gases corresponding to the selected plurality of compressed air paths are mixed in the aggregated air path and then discharged through the first ball valve;

[0080] S541: Open the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches 10 -1 When the vacuum pressure drops below Pa, turn on the vacuum pressure gauge;

[0081] S542: adjusting the throttle valves on the selected plurality of compressed gas lines according to the partial pressure ratio of the gas monitored by the vacuum partial pressure gauge until the partial pressure ratio of the gas monitored by the vacuum partial pressure gauge reaches the target ratio value, and closing the vacuum fine-tuning valve;

[0082] S550: Introducing gas from the selected plurality of compressed gas lines into the vacuum chamber to maintain the vacuum degree in the vacuum chamber at a target vacuum degree.

[0083] In one embodiment, the target vacuum degree is 10 5 Pa~10 3 Pa, step S550 includes:

[0084] S5511: Close the third flapper valve, the plug valve, the turbomolecular pump, and the mechanical pump;

[0085] S5512: Open the second ball valve and the eighth throttle valve until the reading of the first thermal conductivity vacuum gauge reaches the target vacuum degree, and then close the second ball valve.

[0086] In one embodiment, the target vacuum degree is 10 3 Pa~10 1 Pa, step S550 includes:

[0087] S5521: Keep the mechanical pump and the first thermal conductivity vacuum gauge turned on, close the third flapper valve, the plug valve, and the turbomolecular pump, and open the first flapper valve;

[0088] S5522: Open the second ball valve, open and adjust the eighth throttle valve until the vacuum degree in the vacuum chamber is dynamically balanced at the target vacuum degree.

[0089] In one embodiment, the target vacuum degree is 10 1 Pa~10 -1 Pa, step S550 includes:

[0090] S5531: Keep the mechanical pump, the third flapper valve, the plug valve, the turbomolecular pump, and the first thermal conductivity vacuum gauge open;

[0091] S5532: Open and adjust the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches a dynamic balance at the target vacuum degree.

[0092] In one embodiment, the target vacuum degree is 10 -1 Pa~10 -3 Pa, step S550 includes:

[0093] S5541: Wrap heating tape around the gas path where the mechanical pump, the third damper valve, the gate valve, and the turbomolecular pump are located, and around the vacuum chamber, and heat the heating tape to above 120° C. In this heated state, keep the mechanical pump, the third damper valve, the gate valve, and the turbomolecular pump open and running continuously for at least 48 hours.

[0094] S5542: Keep the mechanical pump, the third flapper valve, the plug valve, the turbomolecular pump, and the first thermal conductivity vacuum gauge continuously turned on, and open and adjust the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches dynamic equilibrium at the target vacuum degree;

[0095] S5543: Vacuum pressure gauge monitoring: Turn on the vacuum pressure gauge and record the composition and proportion of the impurity gas in the vacuum chamber according to the reading of the vacuum pressure gauge.

[0096] The above-mentioned vacuum friction tester atmosphere control device can realize the humidity control of the air atmosphere, the vacuum control of different single gases, the vacuum control of volatile liquids with different saturated vapor pressures, and the normal pressure mixing and vacuum control of mixed gases in different proportions, thereby facilitating tests under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0097] Figure 1 Schematic diagram of an atmosphere control device for a vacuum friction testing machine according to an embodiment.

[0098] DESCRIPTION OF REFERENCE NUMERALS: Vacuum chamber 10; friction tester 20; vacuum friction tester atmosphere control device 100; aggregate gas circuit 110; first compressed gas circuit 112; second compressed gas circuit 114; third compressed gas circuit 116; fourth compressed gas circuit 118; first compressed gas source 120; second compressed gas source 122; third compressed gas source 124; fourth compressed gas source 126; first pressure reducing valve 128; first barometer 130; first throttle valve 132; second pressure reducing valve 134; second barometer 136; second throttle valve 138; third pressure reducing valve 140; third barometer 142; third throttle valve 144; fourth pressure reducing valve 146; fourth barometer 148; fourth throttle valve 150; first gas circuit 152; second gas circuit 154; liquid container 156; gas mixing container 158; connecting pipe 16 0; third gas path 162; first humidity sensor 164; fifth throttle valve 166; sixth throttle valve 168; seventh throttle valve 170; first branch 172; second branch 174; third branch 176; fourth branch 178; mechanical pump 180; first ball valve 182; second ball valve 184; eighth throttle valve 186; vacuum fine-tuning valve 188; third ball valve 190; gas concentration sensor 192; second humidity sensor 194; ionization vacuum gauge 196; first thermal conductivity vacuum gauge 198; vacuum partial pressure gauge 200; first baffle valve 210; second baffle valve 212; turbomolecular pump 214; third baffle valve 216; plug valve 218; second thermal conductivity vacuum gauge 220; porous bubbler 222; check valve 224; muffler 226; safety valve 228; fifth barometer 230. DETAILED DESCRIPTION

[0099] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth numerous specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0100] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0101] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0102] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0103] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0104] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0105] Please Figure 1 As shown, one embodiment of the present application provides a vacuum friction tester atmosphere control device 100. A friction tester 20 is disposed within a vacuum chamber 10. The vacuum friction tester atmosphere control device 100 is used to control the atmosphere within the vacuum chamber 10, thereby providing an experimental atmosphere for the friction tester 20 to perform a friction experiment.

[0106] The vacuum friction testing machine atmosphere control device 100 includes: at least two compressed air circuits (not shown) and a collection air circuit 110, the input end of each compressed air circuit is used to connect to a compressed gas source, and the output ends of the at least two compressed air circuits are commonly connected to the input end of the collection air circuit 110.

[0107] Each compressed gas circuit is equipped with a pressure reducing valve, a barometer, and a throttle valve, arranged in sequence along the direction of gas flow within the compressed gas circuit. The pressure reducing valve reduces the pressure of the compressed gas upon entering the compressed gas circuit. The barometer provides convenient information on the pressure of the compressed gas upon entering the compressed gas circuit. By adjusting the opening and closing of the throttle valve, the flow rate of gas in the compressed gas circuit into the collecting gas circuit 110 can be controlled.

[0108] In some embodiments, there may be four compressed gas circuits, namely a first compressed gas circuit 112, a second compressed gas circuit 114, a third compressed gas circuit 116, and a fourth compressed gas circuit 118. The first compressed gas circuit 112 is connected to a first compressed gas source 120. The second compressed gas circuit 114 is connected to a second compressed gas source 122. The third compressed gas circuit 116 is connected to a third compressed gas source 124. The fourth compressed gas circuit 118 is connected to a fourth compressed gas source 126. The first compressed gas circuit 112 is provided with a first pressure reducing valve 128, a first barometer 130, and a first throttle valve 132. The second compressed gas circuit 114 is provided with a second pressure reducing valve 134, a second barometer 136, and a second throttle valve 138. The third compressed gas circuit 116 is provided with a third pressure reducing valve 140, a third barometer 142, and a third throttle valve 144. The fourth compressed air line 118 is provided with a fourth pressure reducing valve 146 , a fourth air pressure gauge 148 , and a fourth throttle valve 150 .

[0109] Optionally, the number of compressed air circuits may be two, three, five, etc., without limitation.

[0110] The vacuum friction testing machine atmosphere control device 100 further includes a first air path 152 , a second air path 154 , a liquid container 156 , a gas mixing container 158 , a connecting pipe 160 , a third air path 162 and a first humidity sensor 164 .

[0111] A first gas path 152 and a second gas path 154 are provided between the fourth pressure reducing valve 146 and the fourth throttle valve 150 provided on the fourth compressed gas path 118. One end of the first gas path 152 is connected to the fourth compressed gas path 118, and the other end extends into a liquid container 156. One end of the second gas path 154 is connected to the fourth compressed gas path 118, and the other end extends into a gas mixing container 158. A fifth throttle valve 166 is provided on the first gas path 152, and a sixth throttle valve 168 is provided on the second gas path 154. The liquid container 156 and the gas mixing container 158 are connected via a connecting pipe 160. By adjusting the opening and closing degree of the fifth throttle valve 166, the flow rate of gas from the first gas path 152 into the liquid container 156 is controlled. By adjusting the opening and closing degree of the sixth throttle valve 168, the flow rate of gas from the second gas path 154 into the gas mixing container 158 is controlled.

[0112] Alternatively, a first air path and a second air path may be provided between the pressure reducing valve and the throttle valve on any other compressed air path. One end of the first air path is connected to the compressed air path, and the other end extends into the liquid container, and one end of the second air path is connected to the compressed air path, and the other end extends into the gas mixing container.

[0113] The input end of third gas path 162 extends into gas mixing container 158, and the output end of third gas path 162 is connected to the input end of aggregate gas path 110. A seventh throttle valve 170 is provided on third gas path 162. Adjusting the opening and closing degree of seventh throttle valve 170 controls the flow rate of gas from third gas path 162 into aggregate gas path 110. A first humidity sensor 164 is provided on third gas path 162, upstream of seventh throttle valve 170, along the direction of gas flow within third gas path 162.

[0114] The vacuum friction testing machine atmosphere control device 100 further includes a first branch 172 , a second branch 174 , a third branch 176 , a fourth branch 178 and a mechanical pump 180 .

[0115] The input end of the first branch 172 is connected to the output end of the aggregate gas circuit 110. A first ball valve 182 is provided on the first branch 172. The output end of the first branch 172 is connected to a gas recovery container or vented to the atmosphere. The input end of the second branch 174 is connected to the output end of the aggregate gas circuit 110. The output end of the second branch 174 is connected to the vacuum chamber 10. A second ball valve 184 and an eighth throttle valve 186 are provided on the second branch 174. Along the direction of gas flow in the second branch 174, the second ball valve 184 is located upstream of the eighth throttle valve 186. One end of the third branch 176 is connected to the output end of the aggregate gas circuit 110, and the other end is connected to the vacuum chamber 10. A vacuum fine-tuning valve 188 is provided on the third branch 176. The input end of the fourth branch 178 is connected to the output end of the aggregate gas circuit 110. The output end of the fourth branch 178 is connected to the mechanical pump 180. A third ball valve 190 is provided on the fourth branch 178. The exhaust port of the mechanical pump 180 is used to connect to a gas recovery container or to be vented to the atmosphere.

[0116] The vacuum friction tester atmosphere control device 100 further includes a gas concentration sensor 192 connected to the vacuum chamber 10 , a second humidity sensor 194 , an ionization vacuum gauge 196 , a first thermal conductivity vacuum gauge 198 , and a vacuum partial pressure gauge 200 .

[0117] The vacuum friction tester atmosphere control device 100 also includes a first damper valve 210, a second damper valve 212, a turbomolecular pump 214, a third damper valve 216, a gate valve 218, and a second thermal conductivity vacuum gauge 220. The first damper valve 210 has one end connected to the vacuum chamber 10 and the other end connected to the mechanical pump 180. The second damper valve 212 has one end connected to the vacuum chamber 10 and the other end open to the atmosphere. The gate valve 218 has one end connected to the vacuum chamber 10 and the other end connected to the turbomolecular pump 214. The turbomolecular pump 214 is connected to the mechanical pump 180 via the third damper valve 216. A second thermal conductivity vacuum gauge 220 is provided on the fourth branch 178, upstream of the mechanical pump 180 along the direction of gas flow within the fourth branch 178.

[0118] In an optional technical solution, the liquid container 156 has a liquid level observation window to facilitate observation of the liquid level in the liquid container 156 .

[0119] In an optional technical solution, a porous foamer 222 is provided at one end of the first gas path 152 extending into the liquid container 156 .

[0120] In an optional technical solution, a check valve 224 is provided on the first branch 172 . Along the direction of gas flow in the first branch 172 , the check valve 224 is provided downstream of the first ball valve 182 .

[0121] In an optional technical solution, the second flapper valve 212 is connected to the atmosphere through a muffler 226 .

[0122] In an optional technical solution, a safety valve 228 is provided on the second branch 174. The safety valve 228 is arranged between the eighth throttle valve 186 and the vacuum chamber 10. When the eighth throttle valve 186 is opened, the safety valve 228 can be opened to prevent a safety accident from occurring in the vacuum chamber 10.

[0123] In an optional technical solution, a fifth barometer 230 is provided on the aggregate gas line 110 to measure the gas pressure in the aggregate gas line 110. When the eighth throttle valve 186 is opened, the fifth barometer 230 is also opened. If the gas pressure in the aggregate gas line 110 is lower than atmospheric pressure, the opening and closing degree of the eighth throttle valve 186 is adjusted to ensure that the gas pressure in the aggregate gas line 110 is no lower than atmospheric pressure. This prevents the infiltration of external air into the aggregate gas line 110 due to negative pressure, thereby preventing the external air from affecting the gas humidity within the vacuum chamber 10.

[0124] In an alternative technical solution, a check valve 224 is provided on the first branch 172. Along the direction of gas flow within the first branch 172, the check valve 224 is positioned downstream of the first ball valve 182. Opening the first ball valve 182 also opens the check valve 224. As the gas from the aggregate gas line 110 is discharged through the first branch 172 to the atmosphere or a gas recovery container, the check valve 224 prevents the gas from flowing back.

[0125] The following describes some vacuum friction tester atmosphere control methods, all of which are implemented using the vacuum friction tester atmosphere control device 100 of any of the above technical solutions. In the vacuum friction tester atmosphere control methods described below, unless otherwise specified, the components in the vacuum friction tester atmosphere control device 100 are assumed to be in the off state in the initial state. The following description uses "medium vacuum" and "high vacuum", where the medium vacuum range is 10 2 Pa~10 -1 Pa, the high vacuum range is 10 - 1 Pa~10 -5 Pa.

[0126] An embodiment of the present application provides a method for controlling the atmosphere of a vacuum friction tester. The method is a method for controlling the humidity of the air atmosphere. The method is implemented using the vacuum friction tester atmosphere control device 100 of any of the above embodiments. The method includes the following steps:

[0127] S110: A compressed air source is selected as the compressed gas source (the compressed gas source 126 in this embodiment) connected to the compressed gas circuit (the fourth compressed gas circuit 118 in this embodiment) connecting the first gas circuit 152 and the second gas circuit 154, and deionized water is placed in the liquid container 156.

[0128] It can be understood that in other embodiments, the compressed air circuit connected to the first air circuit 152 and the second air circuit 154 can also be any other compressed air circuit.

[0129] S120 : Open the first thermal conductivity vacuum gauge 198 , the mechanical pump 180 , and the first baffle valve 210 to evacuate the vacuum chamber 10 to a medium vacuum, and then close the first thermal conductivity vacuum gauge 198 , the mechanical pump 180 , and the first baffle valve 210 .

[0130] Specifically, the gas in the vacuum chamber 10 can be extracted by the mechanical pump 180 through the first baffle valve 210 and discharged into the atmosphere or a gas recovery container. During the process of the mechanical pump 180 extracting the gas in the vacuum chamber 10, the vacuum degree in the vacuum chamber 10 can be known by the reading of the first thermal conductivity vacuum gauge 198. Therefore, when the vacuum degree in the vacuum chamber 10 reaches the vacuum degree target value (within the medium vacuum range, for example, 10 2 Pa), the mechanical pump 180 and the first flapper valve 210 can be closed.

[0131] In this step, the vacuum chamber 10 is evacuated to a medium vacuum state, thereby removing the residual gas in the vacuum chamber 10. This prevents the residual gas in the vacuum chamber 10 from interfering with the air humidity in the vacuum chamber 10 when air is introduced into the vacuum chamber 10 in subsequent steps S140 to S150, thereby facilitating more accurate and effective control of the air humidity in the vacuum chamber 10.

[0132] S130: includes: S131, S132 and S133, among which:

[0133] S131: Turn on the first humidity sensor 164 and the first ball valve 182, and fully open the seventh throttle valve 170;

[0134] S132: Open and adjust the pressure reducing valve (the fourth pressure reducing valve 146 in this embodiment) on the compressed air circuit (the fourth compressed air circuit 118 in this embodiment) connected to the first air circuit 152 and the second air circuit 154 so that the pressure gauge (the fourth air pressure gauge 148 in this embodiment) on the compressed air circuit reads 0.1 MPa to 0.2 MPa;

[0135] S133: Open and adjust the fifth throttle valve 166 and the sixth throttle valve 168 so that the reading of the first humidity sensor 164 reaches the target humidity value.

[0136] Specifically, after fifth throttle valve 166 is opened, compressed air from the compressed air circuit (in this embodiment, fourth compressed air circuit 118) connecting first air circuit 152 and second air circuit 154 flows through first air circuit 152 into liquid container 156. This compressed air passes through deionized water, increasing its humidity and becoming relatively humid. This relatively humid compressed air then enters gas mixing container 158 through connecting pipe 160. After sixth throttle valve 168 is opened, compressed air from the compressed air circuit (in this embodiment, fourth compressed air circuit 118) connecting first air circuit 152 and second air circuit 154 flows through second air circuit 154 into gas mixing container 158. The relatively humid compressed air from liquid container 156 and the relatively dry compressed air from second air circuit 154 are mixed in gas mixing container 158 before flowing into third air circuit 162. The air then flows through converging air circuit 110 to first branch circuit 172, where it is discharged into the atmosphere or into a gas recovery container.

[0137] By adjusting the opening and closing degrees of the fifth throttle valve 166 and the sixth throttle valve 168, the flow rate of relatively humid compressed air and the flow rate of relatively dry compressed air can be adjusted respectively, so that the reading of the first humidity sensor 164 can be adjusted (equal to the air humidity in the third air path 162), and the air humidity in the third air path 162 can reach the humidity target value.

[0138] Since the purpose of step S130 is to adjust the air humidity in the third air path 162 to the target humidity value, opening the first ball valve 182 facilitates the discharge of the air flowing through the third air path 162 during the process of adjusting the air humidity in the third air path 162, so that the third air path 162 has sufficient air flow.

[0139] S140 : Open the first thermal conductivity vacuum gauge 198 , the second ball valve 184 and the eighth throttle valve 186 until the reading of the first thermal conductivity vacuum gauge 198 reaches atmospheric pressure, then close the first ball valve 182 and open the second flapper valve 212 .

[0140] Specifically, after the second ball valve 184 and the eighth throttle valve 186 are opened in step S140, the air in the third gas path 162 flows sequentially through the converging gas path 110 and the second branch 174 into the vacuum chamber 10. Because the fifth throttle valve 166 and the sixth throttle valve 168 have been adjusted in step S130 to maintain the humidity of the air in the third gas path 162 at the target humidity value, when the air in the third gas path 162 flows sequentially through the converging gas path 110 and the second branch 174 into the vacuum chamber 10 in step S140, the humidity of the air in the vacuum chamber 10 substantially reaches the target humidity value, thereby preliminarily controlling the humidity of the air in the vacuum chamber 10 at the target humidity value.

[0141] Since the first ball valve 182 is opened in step S130, when the second ball valve 184 and the eighth throttle valve 186 are opened in step S140, the air in the third gas path 162 flows into the first branch path 172 and the second branch path 174 respectively through the aggregate gas path 110. The air in the first branch path 172 is discharged to the atmosphere or the gas recovery container through the first ball valve 182, and the air in the second branch path 174 flows into the vacuum chamber 10. Therefore, the opening of the first ball valve 182 can maintain a large flow rate of air flowing out of the third gas path 162 and the aggregate gas path 110. In this way, the first humidity sensor 164 can quickly detect changes in the air humidity in the third gas path 162. When the reading of the first humidity sensor 164 does not meet the humidity target value, the opening and closing degrees of the fifth throttle valve 166 and the sixth throttle valve 168 can be adjusted in a timely manner to ensure that the air humidity in the third gas path 162 is quickly and stably maintained at the humidity target value, thereby facilitating the rapid and stable control of the air humidity in the vacuum chamber 10 at the humidity target value.

[0142] After the air in the second branch 174 flows into the vacuum chamber 10, the pressure in the vacuum chamber 10 gradually increases until the reading of the first thermal conductivity vacuum gauge 198 reaches atmospheric pressure (that is, the air pressure in the vacuum chamber 10 reaches atmospheric pressure). At this time, if the air in the second branch 174 continues to enter the vacuum chamber 10, the air pressure in the vacuum chamber 10 will exceed the atmospheric pressure. Therefore, the first ball valve 182 is closed and the second baffle valve 212 is opened. The air in the vacuum chamber 10 can be discharged to the atmosphere through the second baffle valve 212 to prevent the air pressure in the vacuum chamber 10 from being too high.

[0143] Moreover, since the second baffle valve 212 is opened, the air flowing out of the third air path 162 and the aggregate air path 110 has an outflow channel after entering the vacuum chamber 10 through the second branch 174. Therefore, when the first ball valve 182 is closed when the reading of the first thermal conductivity vacuum gauge 198 reaches atmospheric pressure, the air flowing out of the third air path 162 and the aggregate air path 110 can all enter the vacuum chamber 10 and can maintain a large flow rate. In this way, the first humidity sensor 164 can also quickly capture the change of the air humidity in the third air path 162, so that when the reading of the first humidity sensor 164 does not meet the humidity target value, the opening and closing degree of the fifth throttle valve 166 and the sixth throttle valve 168 can be adjusted in time to make the air humidity in the third air path 162 quickly and stably maintained at the humidity target value, which is conducive to making the air humidity in the vacuum chamber 10 quickly and stably controlled at the humidity target value.

[0144] S150: includes S151, S152, and S153, wherein:

[0145] S151: Turn on the second humidity sensor 194;

[0146] S152: Adjusting the opening and closing degrees of the fifth throttle valve 166 and the sixth throttle valve 168 according to the difference between the humidity target value and the reading of the second humidity sensor 194 so that the change in the reading of the first humidity sensor 164 is equal to an iteration value (e.g., the difference);

[0147] S153: Repeat step S152 until the reading of the second humidity sensor 194 reaches the humidity target value.

[0148] Because the second humidity sensor 194 is connected to the vacuum chamber 10, it can more accurately reflect the air humidity within the vacuum chamber 10. The first humidity sensor 164 can more accurately reflect the humidity of the gas in the third gas path 162, that is, the intake air humidity before the air enters the vacuum chamber 10. In step S150, when the air humidity within the vacuum chamber 10 (the reading of the second humidity sensor 194) does not meet the target humidity value, the opening and closing degrees of the fifth throttle valve 166 and the sixth throttle valve 168 are adjusted to change the reading of the first humidity sensor 164, that is, to adjust the intake air humidity before the air enters the vacuum chamber 10 (that is, the gas humidity in the third gas path 162). This allows for rapid response and feedback on the air humidity within the vacuum chamber 10, thereby rapidly controlling the air humidity within the vacuum chamber 10 to the target humidity value.

[0149] In an optional technical solution, a porous foamer 222 is provided at one end of the first gas path 152 extending into the liquid container 156. The porous foamer 222 can enable the gas in the first gas path 152 to fully contact with the deionized water, effectively increasing the humidity.

[0150] An embodiment of the present application provides a method for controlling the atmosphere of a vacuum friction tester. The method is a method for controlling the vacuum degree of different single gases. The method is implemented using the vacuum friction tester atmosphere control device 100 of any of the above embodiments. The method includes the following steps:

[0151] S210: including: including: S211 and S212, wherein:

[0152] S211: Select any compressed gas circuit, and connect the input end of the selected compressed gas circuit to a compressed gas source, wherein the single gas to be introduced into the vacuum chamber 10 is used as the compressed gas in the compressed gas source.

[0153] S212: Open and adjust the pressure reducing valve on the selected compressed air line so that the reading of the pressure gauge on the compressed air line is 0.1 MPa to 0.2 MPa.

[0154] Specifically, in this embodiment, the selected compressed gas circuit is the first compressed gas circuit 112. The input end of the selected compressed gas circuit is connected to the first compressed gas source 120. The pressure reducing valve and the pressure gauge on the selected compressed gas circuit are the first pressure reducing valve 128 and the first pressure gauge 130.

[0155] S220 : Open the first thermal conductivity vacuum gauge 198 , the mechanical pump 180 , the first baffle valve 210 , the second thermal conductivity vacuum gauge 220 , and the third ball valve 190 , so that the readings of the first thermal conductivity vacuum gauge 198 and the second thermal conductivity vacuum gauge 220 are both medium vacuum.

[0156] Specifically, the gas within the vacuum chamber 10 can be extracted by the mechanical pump 180 through the first flapper valve 210 and discharged to the atmosphere or into a gas recovery container, thereby achieving a medium vacuum level within the vacuum chamber 10 (i.e., equal to the reading on the first thermal conductivity vacuum gauge 198). Since the third ball valve 190 is open, the mechanical pump 180 can also extract gas from the fourth branch 178 and the converging gas line 110 and discharge it to the atmosphere or into a gas recovery container, thereby achieving a medium vacuum level within the fourth branch 178 and the converging gas line 110 (i.e., equal to the reading on the second thermal conductivity vacuum gauge 220).

[0157] S230: Close the mechanical pump 180, the first baffle valve 210 and the third ball valve 190, and open the throttle valve (the first throttle valve 132 in this embodiment), the second ball valve 184 and the eighth throttle valve 186 on the selected compressed air path to inflate the vacuum chamber 10 to a vacuum degree of 10 4 The vacuum level in the vacuum chamber 10 can be known by the reading of the first thermal conductivity vacuum gauge 198 .

[0158] S240 : Repeat step S220 and step S230 at least three times, then execute step S220 again, and then close the third ball valve 190 .

[0159] In step S220, the vacuum chamber 10 is evacuated to a medium vacuum, and the fourth branch 178 and the converging gas line 110 are evacuated to a medium vacuum, thereby removing the residual gas in the vacuum chamber 10 and the residual gas in the fourth branch 178 and the converging gas line 110. In step S230, compressed gas is introduced into the vacuum chamber 10, thereby replacing the compressed gas in the fourth branch 178, the converging gas line 110, and the entire vacuum chamber 10. By repeating steps S220 and S230 at least three times before performing step S220, the residual gas in the fourth branch 178, the converging gas line 110, and the vacuum chamber 10 can be fully removed. Thus, when the compressed gas is introduced into the vacuum chamber 10 in subsequent steps, the residual gas in the fourth branch 178, the converging gas line 110, and the vacuum chamber 10 can be prevented from affecting the purity and vacuum level of the compressed gas in the vacuum chamber 10, thereby facilitating more accurate and effective control of the purity and vacuum level of the compressed gas in the vacuum chamber 10.

[0160] Specifically, in step S230, the vacuum chamber 10 is filled with compressed gas until 10 4 Pa level, the amount of gas consumed is appropriate and the residual gas in the fourth branch 178, the collecting gas line 110 and the vacuum chamber 10 can be replaced at a relatively fast speed, which is both fast and economical.

[0161] S250: Introducing compressed gas from the selected compressed gas path into the vacuum chamber 10 to maintain the vacuum degree in the vacuum chamber 10 at the target vacuum degree.

[0162] Specifically, after the fourth branch 178, the aggregate gas line 110, and the vacuum chamber 10 are fully purged of residual gas in step S240, compressed gas needs to be introduced into the vacuum chamber 10 to control the vacuum level within the vacuum chamber 10 to maintain the target vacuum level. However, different control methods are required depending on the target vacuum level range. The following four control methods are introduced:

[0163] A1. The target vacuum degree is 10 5 Pa~10 3 Pa, step S250 includes:

[0164] S2511: Turn off the mechanical pump 180 and the first flapper valve 210, and keep the first thermal conductivity vacuum gauge 198 open.

[0165] S2512: The throttle valve (in this embodiment, the first throttle valve 132), second ball valve 184, and eighth throttle valve 186 on the selected compressed air path are opened until the reading of the first thermal conductivity vacuum gauge 198 reaches the target vacuum level. The second ball valve 184 is then closed to maintain the vacuum level within the vacuum chamber 10 at the target vacuum level. This step utilizes a static pressure maintenance method to maintain the vacuum level within the vacuum chamber 10 at the target vacuum level.

[0166] B1. The target vacuum degree is 10 3 Pa~10 1 Pa, step S250 includes:

[0167] S2521 : Keep the first flapper valve 210 , the mechanical pump 180 and the first thermal conductivity vacuum gauge 198 open, so that the mechanical pump 180 continues to draw a vacuum into the vacuum chamber 10 .

[0168] S2522: Fully open the throttle valve on the selected compressed air circuit (in this embodiment, the first throttle valve 132), open the second ball valve 184, open and adjust the eighth throttle valve 186 until the vacuum degree in the vacuum chamber 10 is dynamically balanced at the target vacuum degree.

[0169] By opening and adjusting the eighth throttle valve 186, the flow rate of compressed gas entering the vacuum chamber 10 can be adjusted. This step continuously evacuates the vacuum chamber 10 and adjusts the opening and closing degree of the eighth throttle valve 186 to adjust the flow rate of compressed gas entering the vacuum chamber 10. This dynamically adjusts the vacuum level within the vacuum chamber 10 until the vacuum level within the vacuum chamber 10 reaches a dynamic equilibrium at the target vacuum level.

[0170] C1. Target vacuum degree is 10 1 Pa~10 -1 Pa, step S250 includes:

[0171] S2531: Close the first flapper valve 210, keep the mechanical pump 180 and the first thermal conductivity vacuum gauge 198 open, open the third flapper valve 216, the plug valve 218, the turbomolecular pump 214, and the ionization vacuum gauge 196 to evacuate the vacuum chamber 10 to a vacuum degree of 10 -1 Pa or less, thereby further minimizing the impact of residual gas in the vacuum chamber 10 on the purity and vacuum degree of the compressed gas in the vacuum chamber 10, thereby facilitating more accurate and effective control of the purity and vacuum degree of the compressed gas in the vacuum chamber 10. The ionization vacuum gauge 196 can measure 10 -1 Vacuum degree below Pa.

[0172] S2532: Fully open the throttle valve on the selected compressed air circuit (the first throttle valve 132 in this embodiment), open and adjust the vacuum fine-tuning valve 188 until the vacuum degree in the vacuum chamber 10 reaches a dynamic balance at the target vacuum degree.

[0173] In this step, the vacuum degree in the vacuum chamber 10 can be dynamically adjusted by continuously drawing a high vacuum in the vacuum chamber 10 and adjusting the opening and closing degree of the vacuum fine-tuning valve 188 to adjust the flow rate of the compressed gas entering the vacuum chamber 10, until the vacuum degree in the vacuum chamber 10 is dynamically balanced at the target vacuum degree.

[0174] D1. Target vacuum degree is 10 -1 Pa~10 -3 Pa, step S250 includes:

[0175] S2541: Close the first baffle valve 210, and wind heating tapes around the gas path where the mechanical pump 180, the third baffle valve 216, the plug valve 218, and the turbomolecular pump 214 are located, and around the vacuum chamber 10, and heat the heating tapes to above 120°C. In this heating state, keep the mechanical pump 180, the third baffle valve 216, the plug valve 218, and the turbomolecular pump 214 open and running continuously for more than 48 hours, so that the vacuum chamber 10 can be evacuated to almost the ultimate vacuum, thereby further avoiding to the greatest extent possible the influence of residual gas in the vacuum chamber 10 on the purity and vacuum degree of the compressed gas in the vacuum chamber 10, which is conducive to more accurate and effective control of the purity and vacuum degree of the compressed gas in the vacuum chamber 10.

[0176] S2542: Keep the mechanical pump 180, the third baffle valve 216, the plug valve 218, the turbomolecular pump 214, and the first thermal conductivity vacuum gauge 198 continuously open so that the vacuum chamber 10 can be continuously evacuated to a high vacuum. Fully open the throttle valve on the selected compressed gas line (in this embodiment, the first throttle valve 132), open and adjust the vacuum fine-tuning valve 188 until the vacuum level in the vacuum chamber 10 reaches a dynamic equilibrium at the target vacuum level. This step dynamically adjusts the vacuum level in the vacuum chamber 10 by continuously evacuating the vacuum chamber 10 and adjusting the opening and closing degree of the vacuum fine-tuning valve 188 to adjust the flow rate of compressed gas entering the vacuum chamber 10, until the vacuum level in the vacuum chamber 10 reaches a dynamic equilibrium at the target vacuum level.

[0177] S2543: Turn on the vacuum partial pressure gauge 200 and record the composition and proportion of the impurity gas in the vacuum chamber 10 according to the reading of the vacuum partial pressure gauge 200, so as to determine the limitations of the experimental atmosphere.

[0178] One embodiment of the present application provides a method for controlling the atmosphere of a vacuum friction tester. The method is a method for controlling the vacuum degree of volatile liquids with different saturated vapor pressures. The method is implemented using the vacuum friction tester atmosphere control device 100 of any of the above embodiments. The method includes the following steps:

[0179] S310: Volatile liquid is placed in the liquid container 156. Volatile liquids with different saturated vapor pressures can be selected according to experimental requirements.

[0180] S320: The second thermal conductivity vacuum gauge 220, mechanical pump 180, third ball valve 190, and seventh throttle valve 170 are turned on. When mechanical pump 180 is running, it accelerates the volatilization of the volatile liquid into gas. The gas generated by the volatilization of the volatile liquid is then sequentially extracted by mechanical pump 180 through third gas path 162, converging gas path 110, and fourth branch path 178. Simultaneously, the third gas path 162, converging gas path 110, and fourth branch path 178 are filled with the gas generated by the volatilization of the volatile liquid. When the reading of the second thermal conductivity vacuum gauge 220 stabilizes, it can be assumed that the third gas path 162, converging gas path 110, and fourth branch path 178 are filled with the gas generated by the volatilization of the volatile liquid. At this point, the third ball valve 190 is closed.

[0181] Through this step, the third gas path 162, the aggregating gas path 110, and the fourth branch 178 are filled with the gas formed by the volatilization of the volatile liquid, so that the residual gas in the third gas path 162, the aggregating gas path 110, and the fourth branch 178 can be replaced by the gas formed by the volatilization of the volatile liquid. Further, when the gas formed by the volatilization of the volatile liquid is filled into the vacuum chamber 10 in the subsequent steps, the residual gas in the third gas path 162, the aggregating gas path 110, and the fourth branch 178 can be prevented from affecting the purity and vacuum degree of the gas formed by the volatilization of the volatile liquid in the vacuum chamber 10, which is conducive to more accurate and effective control of the purity and vacuum degree of the gas formed by the volatilization of the volatile liquid in the vacuum chamber 10.

[0182] S330: Turn on the first thermal conductivity vacuum gauge 198, the mechanical pump 180 and the first baffle valve 210 to pump the vacuum chamber 10 to a medium vacuum (e.g., 10 2 Pa) to evacuate the vacuum chamber 10 to medium vacuum.

[0183] S340: Close the first flapper valve 210, open the third flapper valve 216, the plug valve 218, the turbomolecular pump 214 and the ionization vacuum gauge 196, and pump the vacuum chamber 10 to a vacuum degree of 10 -1 Pa or less. Ionization vacuum gauge 196 can measure 10 -1 Vacuum degree below Pa.

[0184] Steps S330 and S340 can remove the residual gas in the vacuum chamber 10 by evacuating the vacuum chamber 10. Then, when the gas formed by the volatilization of the volatile liquid is filled into the vacuum chamber 10 in the subsequent step S370, the residual gas in the vacuum chamber 10 can be prevented from affecting the purity and vacuum degree of the gas formed by the volatilization of the volatile liquid in the vacuum chamber 10 as much as possible, which is conducive to more accurate and effective control of the purity and vacuum degree of the gas formed by the volatilization of the volatile liquid in the vacuum chamber 10.

[0185] S350: Open the second ball valve 184 and the eighth throttle valve 186. When the reading of the first thermal conductivity vacuum gauge 198 rises to 10 1 When the pressure is above 10 Pa, close the eighth throttle valve 186 until the reading of the ionization vacuum gauge 196 is 10 -1 Below Pa.

[0186] In this step, after the second ball valve 184 and the eighth throttle valve 186 are opened, the gas generated by the volatile liquid can be introduced into the vacuum chamber 10, so that the reading of the first thermal conductivity vacuum gauge 198 rises to 10. 1 Pa or more. At this time, the eighth throttle valve 186 is closed, and the gas formed by the volatilization of the volatile liquid cannot be further introduced into the vacuum chamber 10. Since the turbomolecular pump 214 is turned on in step S340, the turbomolecular pump 214 continues to pump a high vacuum to the vacuum chamber 10 during the process of step S350. Therefore, the gas in the vacuum chamber 10 can be gradually discharged until the reading of the ionization vacuum gauge 196 is 10 -1 Below Pa.

[0187] In steps 340 and 350, the vacuum chamber 10 is continuously evacuated to a high vacuum by the mechanical pump 180, the third flapper valve 216, the gate valve 218, and the turbomolecular pump 214; and the gas generated by the volatilization of the volatile liquid is first introduced into the vacuum chamber 10, so that the vacuum degree in the vacuum chamber 10 reaches 10 1 Pa or above, and then the introduction of the gas formed by the volatilization of the volatile liquid into the vacuum chamber 10 is stopped, so that the gas formed by the volatilization of the volatile liquid introduced into the vacuum chamber 10 is gradually discharged. In the process from the gas formed by the volatilization of the volatile liquid entering the vacuum chamber 10 to the process of being discharged from the vacuum chamber 10, the gas formed by the volatilization of the volatile liquid can further remove the small amount of residual gas adsorbed on the inner wall of the vacuum chamber 10 through the effect of competitive adsorption. Therefore, when the gas formed by the volatilization of the volatile liquid is filled into the vacuum chamber 10 in the subsequent step S370, the residual gas in the vacuum chamber 10 can be further prevented from affecting the purity and vacuum degree of the gas formed by the volatilization of the volatile liquid in the vacuum chamber 10, which is conducive to more accurate and effective control of the purity and vacuum degree of the gas formed by the volatilization of the volatile liquid in the vacuum chamber 10.

[0188] S360: Repeat step S350 at least three times to fully remove the small amount of residual gas adsorbed on the inner wall of the vacuum chamber 10 through the competitive adsorption of the gas formed by the volatilization of the volatile liquid. Then, when the gas formed by the volatilization of the volatile liquid is filled into the vacuum chamber 10 in the subsequent step S370, the residual gas in the vacuum chamber 10 can be further prevented from affecting the purity and vacuum degree of the gas formed by the volatilization of the volatile liquid in the vacuum chamber 10, which is conducive to more accurate and effective control of the purity and vacuum degree of the gas formed by the volatilization of the volatile liquid in the vacuum chamber 10.

[0189] S370: introducing gas generated by the volatilization of the volatile liquid into the vacuum chamber 10 to maintain the vacuum degree in the vacuum chamber 10 at the target vacuum degree.

[0190] Specifically, different control methods are required depending on the saturated vapor pressure of the volatile liquid and the target vacuum range. The following four control methods are introduced:

[0191] A2. The saturated vapor pressure of a volatile liquid is 10 3 Above, the target vacuum degree is the saturated vapor pressure of the volatile liquid ~10 3 Pa, step S370 includes:

[0192] S3711: Close the mechanical pump 180, the third flapper valve 216, the gate valve 218, and the turbomolecular pump 214, and keep the first thermal conductivity vacuum gauge 198 open;

[0193] S3712: Open the seventh throttle valve 170, the second ball valve 184, and the eighth throttle valve 186 until the reading of the first thermal conductivity vacuum gauge 198 reaches the target vacuum level. Then, close the second ball valve 184 to maintain the vacuum level within the vacuum chamber 10 at the target vacuum level. This step utilizes a static pressure maintenance method to maintain the vacuum level within the vacuum chamber 10 at the target vacuum level.

[0194] B2. The saturated vapor pressure of a volatile liquid is 10 1 Above, the target vacuum degree is 10 3 Pa~10 1 Pa, step S370 includes:

[0195] S3721: Open the first baffle valve 210, keep the mechanical pump 180 and the first thermal conductivity vacuum gauge 198 open, and close the third baffle valve 216, the plug valve 218, and the turbomolecular pump 214. In this way, the mechanical pump 180 and the first baffle valve 210 can continue to evacuate the vacuum chamber 10.

[0196] S3722: Open the seventh throttle valve 170 and the second ball valve 184, and open and adjust the eighth throttle valve 186 until the vacuum degree in the vacuum chamber 10 is dynamically balanced at the target vacuum degree.

[0197] In this step, the vacuum level in the vacuum chamber 10 is dynamically adjusted by continuously drawing a vacuum in the vacuum chamber 10 and adjusting the opening and closing degree of the eighth throttle valve 186 to adjust the flow rate of the gas generated by the volatilization of the volatile liquid entering the vacuum chamber 10, until the vacuum level in the vacuum chamber 10 is dynamically balanced at the target vacuum level.

[0198] C2. The saturated vapor pressure of a volatile liquid is 10 -1 Above, the target vacuum degree is 101 Pa~10 -1 Pa, step S370 includes:

[0199] S3731: Keep the mechanical pump 180, the third flapper valve 216, the gate valve 218, the turbomolecular pump 214, and the first thermal conductivity vacuum gauge 198 open.

[0200] S3732: Open the seventh throttle valve 170, open and adjust the vacuum fine-tuning valve 188, until the vacuum degree in the vacuum chamber 10 reaches a dynamic balance at the target vacuum degree.

[0201] In this step, the vacuum degree in the vacuum chamber 10 can be dynamically adjusted by continuously drawing a high vacuum in the vacuum chamber 10 and adjusting the opening and closing degree of the vacuum fine-tuning valve 188 to adjust the flow rate of the gas formed by the volatilization of the volatile liquid entering the vacuum chamber 10, until the vacuum degree in the vacuum chamber 10 is dynamically balanced at the target vacuum degree.

[0202] D2. The saturated vapor pressure of a volatile liquid is 10 -3 Above, the target vacuum degree is 10 -1 Pa~10 -3 Pa, step S370 includes:

[0203] S3741: Wrap heating tapes around the gas path where the mechanical pump 180, the third baffle valve 216, the plug valve 218, and the turbomolecular pump 214 are located, and around the vacuum chamber 10, and heat the heating tapes to above 120°C. In this heating state, keep the mechanical pump 180, the third baffle valve 216, the plug valve 218, and the turbomolecular pump 214 open and running continuously for more than 48 hours, so that the vacuum chamber 10 can be evacuated to almost the ultimate vacuum, thereby further avoiding to the greatest extent the influence of residual gas in the vacuum chamber 10 on the purity and vacuum degree of the gas formed by the volatilization of the volatile liquid in the vacuum chamber 10, thereby facilitating more accurate and effective control of the purity and vacuum degree of the gas formed by the volatilization of the volatile liquid in the vacuum chamber 10.

[0204] S3742: Keep the mechanical pump 180, the third baffle valve 216, the plug valve 218, and the turbomolecular pump 214 open to continuously pump high vacuum into the vacuum chamber 10. Open the seventh throttle valve 170, and open and adjust the vacuum fine-tuning valve 188 until the vacuum level in the vacuum chamber 10 reaches dynamic equilibrium at the target vacuum level. By continuously pumping high vacuum into the vacuum chamber 10 and adjusting the opening and closing degree of the vacuum fine-tuning valve 188 to adjust the flow rate of gas generated by the volatilization of the volatile liquid entering the vacuum chamber 10, the vacuum level in the vacuum chamber 10 can be dynamically adjusted until the vacuum level in the vacuum chamber 10 reaches dynamic equilibrium at the target vacuum level.

[0205] S3743: Turn on the vacuum partial pressure gauge 200 and record the composition and proportion of the impurity gas in the vacuum chamber 10 according to the reading of the vacuum partial pressure gauge 200, so as to determine the limitations of the experimental atmosphere.

[0206] One embodiment of the present application provides a method for controlling the atmosphere of a vacuum friction tester. The method is a method for controlling the mixing of mixed gases at normal pressure in different proportions. The method is implemented using the vacuum friction tester atmosphere control device 100 of any of the above embodiments. The method includes the following steps:

[0207] S410: includes: S411 and S412, among which:

[0208] S411: Selecting a plurality of compressed gas circuits, wherein the plurality of compressed gas circuits correspond one-to-one to the types of gases to be mixed, and selecting a compressed gas source of the corresponding type to be connected to the selected compressed gas circuits.

[0209] S412: Open and adjust the pressure reducing valves on the selected multiple compressed air lines so that the readings of the pressure gauges on the multiple compressed air lines are 0.1 MPa to 0.2 MPa.

[0210] Specifically, the following description uses the example of two mixed gases, namely a first compressed gas and a second compressed gas, as an example. The following description uses the first compressed gas circuit 112 and the second compressed gas circuit 114 as an example. Of course, any other two compressed gas circuits may also be selected. The compressed gas source connected to the first compressed gas circuit 112 is selected as the first compressed gas source (i.e., a gas source containing the first compressed gas). The compressed gas source connected to the second compressed gas circuit 114 is selected as the second compressed gas source (i.e., a gas source containing the second compressed gas). The first pressure reducing valve 128 and the first barometer 130 on the first compressed gas circuit 112 are opened. By adjusting the opening and closing degree of the first pressure reducing valve 128 so that the corresponding reading on the first barometer 130 is between 0.1 MPa and 0.2 MPa, the pressure of the first compressed gas entering the first compressed gas circuit 112 is reduced, thereby preventing leakage caused by excessive pressure in the downstream gas circuit. Open the second pressure reducing valve 134 and the second pressure gauge 136 on the second compressed gas circuit 114, and adjust the opening and closing degree of the second pressure reducing valve 134 so that the corresponding reading of the second pressure gauge 136 is 0.1MPa~0.2MPa, so as to reduce the pressure of the second compressed gas when entering the second compressed gas circuit 114, thereby preventing the downstream gas circuit from being subjected to excessive pressure and causing leakage.

[0211] S420 : Open the first thermal conductivity vacuum gauge 198 , the second thermal conductivity vacuum gauge 220 , the mechanical pump 180 , the first baffle valve 210 , and the third ball valve 190 . After the first thermal conductivity vacuum gauge 198 indicates a medium vacuum, close the first baffle valve 210 .

[0212] The gas in the vacuum chamber 10 can be extracted by the mechanical pump 180 through the first baffle valve 210 and discharged into the atmosphere or a gas recovery container. The vacuum degree in the vacuum chamber 10 can be determined by the reading of the first thermal conductivity vacuum gauge 198. Since the third ball valve 190 is open, the mechanical pump 180 can also extract the gas in the fourth branch 178 and the aggregate gas path 110 and discharge it into the atmosphere or a gas recovery container. By evacuating the vacuum chamber 10 to a medium vacuum and evacuating the fourth branch 178 and the aggregate gas path 110 to a medium vacuum, the residual gas in the vacuum chamber 10 can be removed. The residual gas in the fourth branch 178 and the aggregate gas path 110 can be removed. When the gas to be mixed is filled into the vacuum chamber 10 in the subsequent steps, the residual gas in the fourth branch 178, the aggregate gas path 110, and the vacuum chamber 10 can be prevented from affecting the gas components to be mixed in the vacuum chamber 10, thereby facilitating more accurate and effective control of the ratio of the mixed gas in the vacuum chamber 10.

[0213] Next, the gases to be mixed are introduced into the vacuum chamber 10 in sequence according to their respective proportions. For example, the first compressed gas and the second compressed gas are introduced in sequence. Steps S430 and S440 are performed for each gas introduced. Therefore, the number of times steps S430 and S440 are performed is equal to the number of types of gases to be mixed (i.e., the number of compressed gas paths selected in step S410).

[0214] S430: includes: S431 and S432, among which:

[0215] S431: Open the throttle valve on one of the selected compressed air lines until the reading of the second thermal conductivity vacuum gauge 220 rises to 10 4 When the pressure reaches the Pa level, close the throttle valve until the reading of the second thermal conductivity vacuum gauge 220 drops to 10 2 Below Pa.

[0216] S432: After repeating step S431 at least three times, close the third ball valve 190.

[0217] Specifically, when it is necessary to introduce the first compressed gas into the vacuum chamber 10, the compressed gas circuit described in step S430 is the first compressed gas circuit 112, and the throttle valve described in step S430 is the first throttle valve 132. In step S430, when the first throttle valve 132 is opened, the mechanical pump 180 continuously evacuates the first compressed gas circuit 112, the aggregate gas circuit 110, and the fourth branch 178. Furthermore, by opening the first throttle valve 132, the first compressed gas is continuously introduced into the vacuum chamber 10 until the reading of the second thermal conductivity vacuum gauge 220 rises to 10. 4 Pa level (ie, the vacuum degree in the fourth branch 178 is reduced to 104 Pa level), and then the first throttle valve 132 is closed to stop the introduction of the first compressed gas into the vacuum chamber 10. As a result, the first compressed gas in the first compressed gas path 112, the collecting gas path 110, and the fourth branch 178 is gradually discharged under the action of the mechanical pump 180. During the process of the first compressed gas entering and exiting the first compressed gas path 112, the collecting gas path 110, and the fourth branch 178, the residual gas in the first compressed gas path 112, the collecting gas path 110, and the fourth branch 178 is replaced and cleared. Therefore, when the first compressed gas is introduced into the vacuum chamber 10 in step S440, the residual gas in the first compressed gas path 112, the collecting gas path 110, and the fourth branch 178 can be prevented from affecting the purity and partial pressure of the first compressed gas in the vacuum chamber 10, thereby facilitating more accurate and effective control of the ratio of the mixed gases in the vacuum chamber 10.

[0218] After repeating step S431 at least three times, close the third ball valve 190. Due to the repeated operation, the residual gas in the first compressed gas circuit 112, the aggregate gas circuit 110, and the fourth branch 178 can be replaced and cleared to the greatest extent possible, thereby avoiding to the greatest extent possible the residual gas in the first compressed gas circuit 112, the aggregate gas circuit 110, and the fourth branch 178 from affecting the purity and partial pressure of the first compressed gas in the vacuum chamber 10, thereby facilitating more accurate and effective control of the ratio of the mixed gas in the vacuum chamber 10.

[0219] S440: Open the throttle valve, the second ball valve 184 and the eighth throttle valve 186 on a compressed air circuit in step S430 until the increase in the reading of the first thermal conductivity vacuum gauge 198 is equal to the partial pressure of the gas of the corresponding type in the compressed air circuit, and then close the second ball valve 184, the eighth throttle valve 186 and the throttle valve.

[0220] Specifically, as described above, when the first compressed gas needs to be introduced into the vacuum chamber 10, the one compressed gas path described in step S430 is the first compressed gas path 112, and the throttle valve described in step S430 is the first throttle valve 132. Thus, the one compressed gas path described in step S440 is the first compressed gas path 112, and the throttle valve described in step S440 is the first throttle valve 132. Step S440 allows the first compressed gas to be introduced into the vacuum chamber 10 according to its proportion.

[0221] S450: Execute step S430 and step S440 multiple times, wherein the number of times step S430 and step S440 are executed is equal to the number of the selected multiple compressed air circuits, and the compressed air circuit opened each time step S430 and step S440 are executed is different.

[0222] As described above, steps S430 and S440 need to be performed each time each gas is introduced. Therefore, the number of times steps S430 and S440 are performed is equal to the number of types of gases to be mixed (i.e., equal to the number of compressed gas circuits selected in step S410). Each time steps S430 and S440 are performed, a different compressed gas circuit is opened, so that the type of gas introduced into the vacuum chamber 10 is different each time. Furthermore, the gases to be mixed can be introduced into the vacuum chamber 10 in their respective proportions.

[0223] It can be understood that when the second compressed gas needs to be introduced into the vacuum chamber 10, steps S430 and S440 are executed, and the compressed gas path described in step S430 is the second compressed gas path 114, and the throttle valve described in step S430 is the second throttle valve 138.

[0224] S460: includes: S461, S462 and S463, among which,

[0225] S461: Turn on the gas concentration sensor 192. If the proportion of a certain gas is insufficient, repeat step S430, and in step S430, select a compressed gas circuit corresponding to the certain gas. For example, if the proportion of the first compressed gas is insufficient, repeat step S430, and the compressed gas circuit in step S430 is the first compressed gas circuit 112, and the throttle valve in step S430 is the first throttle valve 132, thereby displacing and clearing the residual gas in the first compressed gas circuit 112, the converging gas circuit 110, and the fourth branch 178. Furthermore, when the first compressed gas is introduced into the vacuum chamber 10 in step S462, the residual gas in the first compressed gas circuit 112, the converging gas circuit 110, and the fourth branch 178 can be prevented from affecting the proportion of the first compressed gas.

[0226] S462: Open the throttle valve, the second ball valve 184, and the eighth throttle valve 186 on the compressed gas circuit corresponding to the certain gas to fill the vacuum chamber 10 with the certain gas until the reading of the gas concentration sensor 192 shows that the proportion of the certain gas reaches the target proportion value, then close the second ball valve 184, the eighth throttle valve 186 and the throttle valve.

[0227] Specifically, after step S461, the first throttle valve 132, the second ball valve 184, and the eighth throttle valve 186 are opened to replenish the first compressed gas into the vacuum chamber 10 until the reading of the gas concentration sensor 192 shows that the proportion of the first compressed gas reaches the target proportion value, and then the second ball valve 184, the eighth throttle valve 186 and the throttle valve are closed.

[0228] S463: Open the first ball valve 182 and the vacuum fine-tuning valve 188 until the reading of the first thermal conductivity vacuum gauge 198 drops to normal pressure, and then close the first ball valve 182 and the vacuum fine-tuning valve 188.

[0229] Since the first ball valve 182 and the vacuum fine-tuning valve 188 are opened, the mixed gas in the vacuum chamber 10 can be discharged in sequence through the vacuum fine-tuning valve 188 and the first ball valve 182 until the pressure in the vacuum chamber 10 drops to normal pressure. Then, the first ball valve 182 and the vacuum fine-tuning valve 188 are closed, completing the normal-pressure mixing of the first compressed gas and the second compressed gas in different proportions.

[0230] It is worth noting that in this step, since the opening of the vacuum fine-tuning valve 188 is relatively small, the mixed gas in the vacuum chamber 10 can be slowly discharged from the vacuum fine-tuning valve 188, preventing a certain component in the mixed gas from diffusing too quickly and affecting the proportion of the components in the mixed gas, thereby helping to ensure that the proportion of each component in the mixed gas meets expectations.

[0231] It is understandable that the above-mentioned method for controlling the atmosphere of the vacuum friction tester is not limited to mixing two gases, but may also be three or four gases.

[0232] An embodiment of the present application provides a method for controlling the atmosphere of a vacuum friction tester. The method is a method for controlling the vacuum degree of mixed gases of different proportions. The method is implemented using the vacuum friction tester atmosphere control device 100 of any of the above embodiments. The method includes the following steps:

[0233] S510: Turn on the first thermal conductivity vacuum gauge 198, the mechanical pump 180, the first flapper valve 210 and the third ball valve 190, so that the reading of the first thermal conductivity vacuum gauge 198 is medium vacuum (for example, less than 10 2 Pa), close the third ball valve 190 and the first flapper valve 210.

[0234] The gas in the vacuum chamber 10 can be extracted by the mechanical pump 180 through the first baffle valve 210 and discharged into the atmosphere or a gas recovery container. The vacuum degree in the vacuum chamber 10 can be determined by the reading of the first thermal conductivity vacuum gauge 198. Since the third ball valve 190 is open, the mechanical pump 180 can also extract the gas in the fourth branch 178 and the aggregate gas path 110 and discharge it into the atmosphere or a gas recovery container. By evacuating the vacuum chamber 10 to a medium vacuum and evacuating the fourth branch 178 and the aggregate gas path 110 to a medium vacuum, the residual gas in the vacuum chamber 10 can be removed. The residual gas in the fourth branch 178 and the aggregate gas path 110 can be removed. When the gas to be mixed is filled into the vacuum chamber 10 in the subsequent steps, the residual gas in the fourth branch 178, the aggregate gas path 110, and the vacuum chamber 10 can be prevented from affecting the gas components to be mixed in the vacuum chamber 10, thereby facilitating more accurate and effective control of the ratio of the mixed gas in the vacuum chamber 10.

[0235] S520: Open the third flapper valve 216, the plug valve 218, the turbomolecular pump 214, and the ionization vacuum gauge 196 to pump the vacuum chamber 10 to a vacuum degree of 10 -1 Pa or less. Ionization vacuum gauge 196 can measure 10 -1 Vacuum degree below Pa.

[0236] In step S520, by evacuating the vacuum chamber 10 to a high vacuum, the residual gas in the vacuum chamber 10 can be further removed. Thus, when the gas to be mixed is filled into the vacuum chamber 10 in the subsequent step, the residual gas in the vacuum chamber 10 can be further prevented from affecting the gas composition to be mixed in the vacuum chamber 10, thereby facilitating more accurate and effective control of the ratio of the mixed gas in the vacuum chamber 10.

[0237] S530: includes S531, S532, and S533, wherein:

[0238] S531: Selecting a plurality of compressed gas circuits, wherein the plurality of compressed gas circuits correspond one-to-one to the types of gases to be mixed, and selecting a compressed gas source of the corresponding type to be connected to the selected compressed gas circuits.

[0239] S532: Open and adjust the pressure reducing valves on the selected multiple compressed air lines so that the readings of the pressure gauges on the multiple compressed air lines are 0.1 MPa to 0.2 MPa.

[0240] S533 : Open the first ball valve 182 and the throttle valves on the selected multiple compressed air lines, so that the various types of gases corresponding to the selected multiple compressed air lines are mixed in the aggregate air line 110 and then discharged through the first ball valve 182 .

[0241] Specifically, the following description uses the example of two mixed gases, namely a first compressed gas and a second compressed gas, as an example. The following description uses the first compressed gas circuit 112 and the second compressed gas circuit 114 as an example. Of course, any other two compressed gas circuits may also be selected. The compressed gas source connected to the first compressed gas circuit 112 is selected as the first compressed gas source (i.e., a gas source containing the first compressed gas). The compressed gas source connected to the second compressed gas circuit 114 is selected as the second compressed gas source (i.e., a gas source containing the second compressed gas). The first pressure reducing valve 128 and the first barometer 130 on the first compressed gas circuit 112 are opened. By adjusting the opening and closing degree of the first pressure reducing valve 128 so that the corresponding reading on the first barometer 130 is between 0.1 MPa and 0.2 MPa, the pressure of the first compressed gas entering the first compressed gas circuit 112 is reduced, thereby preventing leakage caused by excessive pressure in the downstream gas circuit. Open the second pressure reducing valve 134 and the second pressure gauge 136 on the second compressed gas circuit 114, and adjust the opening and closing degree of the second pressure reducing valve 134 so that the corresponding reading of the second pressure gauge 136 is 0.1MPa~0.2MPa, so as to reduce the pressure of the second compressed gas when entering the second compressed gas circuit 114, thereby preventing the downstream gas circuit from being subjected to excessive pressure and causing leakage.

[0242] The first throttle valve 132 on the first compressed gas circuit 112 is opened, the second throttle valve 138 on the second compressed gas circuit 114 is opened, and the first ball valve 182 is opened. As a result, the first compressed gas from the first compressed gas circuit 112 and the second compressed gas from the second compressed gas circuit 114 are mixed in the aggregate gas circuit 110 and then discharged through the first ball valve 182, thereby allowing the first compressed gas from the first compressed gas circuit 112 and the second compressed gas from the second compressed gas circuit 114 to be fully mixed in the aggregate gas circuit 110.

[0243] S540: includes: S541 and S542, among which,

[0244] S541: Open the vacuum fine-tuning valve 188 until the vacuum degree in the vacuum chamber 10 reaches 10 -1 After that, open the vacuum partial pressure gauge 200.

[0245] Specifically, since after step S520, the mechanical pump 180, the third flapper valve 216, the plug valve 218, the turbomolecular pump 214, and the ionization vacuum gauge 196 are not closed, the vacuum chamber 10 can be continuously evacuated to a high vacuum. After the vacuum fine-tuning valve 188 is opened, the compressed gases from the selected multiple compressed gas paths enter the vacuum chamber 10 through the vacuum fine-tuning valve 188. In this embodiment, the first compressed gas and the second compressed gas enter the vacuum chamber 10 through the vacuum fine-tuning valve 188. Since the turbomolecular pump 214 continues to evacuate the vacuum chamber 10 to a high vacuum, the vacuum degree in the vacuum chamber 10 can be made to reach 10 -1 Thereafter, the vacuum partial pressure gauge 200 can be opened.

[0246] S542: According to the partial pressure ratio of the gas monitored by the vacuum partial pressure gauge 200, adjust the throttle valves on the selected multiple compressed gas lines until the partial pressure ratio of the gas monitored by the vacuum partial pressure gauge 200 reaches the target ratio value, and close the vacuum fine-tuning valve 188.

[0247] In this embodiment, the opening and closing degrees of the first throttle valve 132 and the second throttle valve 138 are adjusted according to the partial pressure ratio of the first compressed gas and the second compressed gas monitored by the vacuum pressure gauge 200 until the partial pressure ratio of the first compressed gas and the second compressed gas monitored by the vacuum pressure gauge 200 reaches the target ratio value, and the vacuum fine-tuning valve 188 is closed.

[0248] Since the first ball valve 182 is opened in step S530, when the vacuum fine-tuning valve 188 is opened in step S540 and the opening and closing degrees of the first throttle valve 132 and the second throttle valve 138 are adjusted, the mixed gas of the first compressed gas and the second compressed gas mixed in the aggregate gas path 110 flows into the first branch 172 and the third branch 176 respectively. The mixed gas in the first branch 172 is discharged to the atmosphere or the gas recovery container through the first ball valve 182, and the mixed gas in the third branch 176 flows into the vacuum chamber 10 through the vacuum fine-tuning valve 188. It can be seen that the opening of the first ball valve 182 allows the mixed gas of the first compressed gas and the second compressed gas to maintain a large flow rate after being mixed in the aggregate gas path 110. In this way, the vacuum pressure gauge 200 can quickly capture the change in the partial pressure ratio of the first compressed gas and the second compressed gas. Therefore, when the partial pressure ratio of the first compressed gas and the second compressed gas does not meet the target ratio value, the opening and closing degree of the first throttle valve 132 and the second throttle valve 138 can be adjusted in time to adjust the partial pressure ratio of the first compressed gas and the second compressed gas to the target ratio value, which is conducive to quickly and stably controlling the partial pressure ratio of the mixed gas in the vacuum chamber 10 at the target ratio value.

[0249] S550: Introducing gas from the selected plurality of compressed gas lines into the vacuum chamber 10 to maintain the vacuum degree in the vacuum chamber 10 at a target vacuum degree.

[0250] By adjusting the first throttle valve 132 and the second throttle valve 138 in step S540, the partial pressure ratio of the first compressed gas and the second compressed gas, as monitored by the vacuum partial pressure gauge 200, can reach the target ratio. This indicates that the ratio of the flow rate of the first compressed gas flowing through the first compressed gas path 112 to the flow rate of the second compressed gas flowing through the second compressed gas path 114 meets the target ratio of the first compressed gas to the second compressed gas. Therefore, when the first compressed gas and the second compressed gas are introduced into the vacuum chamber 10, the first compressed gas and the second compressed gas can be ensured to enter the vacuum chamber 10 in their respective ratios.

[0251] Specifically, different control methods are required according to the target vacuum range. The following four control methods are introduced:

[0252] A3. The target vacuum degree is 10 5 Pa~10 3 Pa, step S550 includes:

[0253] S5511 : Close the third flapper valve 216 , the gate valve 218 , the turbomolecular pump 214 and the mechanical pump 180 .

[0254] S5512: Open the second ball valve 184 and the eighth throttle valve 186 until the reading of the first thermal conductivity vacuum gauge 198 reaches the target vacuum degree, and then close the second ball valve 184.

[0255] Opening the second ball valve 184 and the eighth throttle valve 186 allows the first compressed gas from the first compressed gas line 112 and the second compressed gas from the second compressed gas line 114 to flow into the vacuum chamber 10 via the second branch 174. When the reading of the first thermal conductivity vacuum gauge 198 reaches the target vacuum level, the second ball valve 184 is closed to maintain the vacuum level within the vacuum chamber 10 at the target level. This maintains the vacuum level within the vacuum chamber 10 at the target level using the static pressure maintenance method.

[0256] B3. Target vacuum degree is 10 3 Pa~10 1 Pa, step S550 includes:

[0257] S5521: Keep the mechanical pump 180 and the first thermal conductivity vacuum gauge 198 turned on so that the mechanical pump 180 continues to pump a vacuum into the vacuum chamber 10. Close the third flapper valve 216, the gate valve 218, and the turbomolecular pump 214, and open the first flapper valve 210.

[0258] S5522: Open the second ball valve 184, and open and adjust the eighth throttle valve 186 until the vacuum degree in the vacuum chamber 10 is dynamically balanced at the target vacuum degree.

[0259] The eighth throttle valve 186 is opened and its opening and closing degree is adjusted to adjust the flow rate of compressed gas entering the vacuum chamber 10. By continuously evacuating the vacuum chamber 10 and adjusting the opening and closing degree of the eighth throttle valve 186 to adjust the flow rate of compressed gas entering the vacuum chamber 10, the vacuum level in the vacuum chamber 10 can be dynamically adjusted until the vacuum level in the vacuum chamber 10 is dynamically balanced at the target vacuum level.

[0260] C3. Target vacuum degree is 10 1 Pa~10 -1 Pa, step S550 includes:

[0261] S5531: Keep the mechanical pump 180, the third flapper valve 216, the gate valve 218, the turbomolecular pump 214, and the first thermal conductivity vacuum gauge 198 open, so as to continuously pump high vacuum into the vacuum chamber 10;

[0262] S5532: Open and adjust the vacuum fine-tuning valve 188 until the vacuum degree in the vacuum chamber 10 reaches a dynamic balance at the target vacuum degree.

[0263] By continuously drawing a high vacuum in the vacuum chamber 10 and adjusting the opening and closing degree of the vacuum fine-tuning valve 188 to adjust the flow of compressed gas entering the vacuum chamber 10, the vacuum degree in the vacuum chamber 10 can be dynamically adjusted until the vacuum degree in the vacuum chamber 10 is dynamically balanced at the target vacuum degree.

[0264] D3. Target vacuum degree is 10 -1 Pa~10 -3 Pa, step S550 includes:

[0265] S5541: Wrap heating tapes around the gas path where the mechanical pump 180, the third baffle valve 216, the plug valve 218, and the turbomolecular pump 214 are located, and around the vacuum chamber 10, and heat the heating tapes to above 120°C. In this heating state, keep the mechanical pump 180, the third baffle valve 216, the plug valve 218, and the turbomolecular pump 214 open and running continuously for more than 48 hours, so that the vacuum chamber 10 can be evacuated to almost the ultimate vacuum, thereby further avoiding to the greatest extent the influence of residual gas in the vacuum chamber 10 on the ratio and vacuum degree of the mixed gas in the vacuum chamber 10, which is conducive to more accurate and effective control of the ratio and vacuum degree of the mixed gas in the vacuum chamber 10.

[0266] S5542: Keep the mechanical pump 180, the third baffle valve 216, the plug valve 218, the turbomolecular pump 214, and the first thermal conductivity vacuum gauge 198 continuously open to continuously pump high vacuum into the vacuum chamber 10. Open and adjust the vacuum fine-tuning valve 188 until the vacuum level in the vacuum chamber 10 reaches dynamic equilibrium at the target vacuum level. This step dynamically adjusts the vacuum level in the vacuum chamber 10 by continuously pumping high vacuum into the vacuum chamber 10 and adjusting the opening and closing degree of the vacuum fine-tuning valve 188 to adjust the flow rate of compressed gas entering the vacuum chamber 10 until the vacuum level in the vacuum chamber 10 reaches dynamic equilibrium at the target vacuum level.

[0267] S5543: Monitoring the vacuum partial pressure meter 200: Turn on the vacuum partial pressure meter 200 and record the composition and proportion of the impurity gas in the vacuum chamber 10 according to the reading of the vacuum partial pressure meter 200, so as to determine the limitations of the experimental atmosphere.

[0268] It is understandable that the above-mentioned method for controlling the atmosphere of the vacuum friction tester is not limited to mixing two gases, but may also be three or four gases.

[0269] The above-mentioned vacuum friction tester atmosphere control device 100 can realize the humidity control of the air atmosphere, the vacuum control of different single gases, the vacuum control of volatile liquids with different saturated vapor pressures, and the normal pressure mixing and vacuum control of mixed gases with different proportions, thereby facilitating tests under different working conditions.

[0270] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0271] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A vacuum friction testing machine atmosphere control device, characterized in that: include: At least two compressed gas circuits and a collection gas circuit, wherein the input end of each compressed gas circuit is used to connect to a compressed gas source, the output ends of the at least two compressed gas circuits are commonly connected to the input end of the collection gas circuit, and each compressed gas circuit is provided with a pressure reducing valve, a barometer, and a throttle valve arranged in sequence along the gas flow direction in the compressed gas circuit; The vacuum friction tester atmosphere control device further includes: a first air path, a second air path, a liquid container, a gas mixing container, a connecting pipe, a third air path, and a first humidity sensor; The first and second air paths are provided between the pressure reducing valve and the throttle valve provided on one of the compressed air paths. One end of the first air path is connected to the compressed air path, and the other end extends into the liquid container and is provided with a porous bubbler. One end of the second air path is connected to the compressed air path, and the other end extends into the gas mixing container. A fifth throttle valve is provided on the first air path, and a sixth throttle valve is provided on the second air path. The liquid container and the gas mixing container are connected via the connecting pipe. The input end of the third gas circuit extends into the gas mixing container, the output end of the third gas circuit is connected to the input end of the collecting gas circuit, and a seventh throttle valve is provided on the third gas circuit; the first humidity sensor is provided on the third gas circuit, and along the direction of gas flow in the third gas circuit, the first humidity sensor is located upstream of the seventh throttle valve; The vacuum friction tester atmosphere control device further comprises: a first branch, a second branch, a third branch, a fourth branch and a mechanical pump; The input end of the first branch is connected to the output end of the aggregate gas circuit, and a first ball valve is provided on the first branch. The output end of the first branch is used to connect to a gas recovery container or to be vented to the atmosphere; the input end of the second branch is connected to the output end of the aggregate gas circuit, and the output end of the second branch is used to be connected to a vacuum chamber. A second ball valve and an eighth throttle valve are provided on the second branch, and along the direction of gas flow in the second branch, the second ball valve is located upstream of the eighth throttle valve; one end of the third branch is connected to the output end of the aggregate gas circuit, and the other end is used to be connected to the vacuum chamber, and a vacuum fine-tuning valve is provided on the third branch; the input end of the fourth branch is connected to the output end of the aggregate gas circuit, and the output end of the fourth branch is connected to the mechanical pump, and a third ball valve is provided on the fourth branch; the exhaust port of the mechanical pump is used to connect to a gas recovery container or to be vented to the atmosphere; The vacuum friction tester atmosphere control device further includes: a gas concentration sensor connected to the vacuum chamber, a second humidity sensor, an ionization vacuum gauge, a first thermal conductivity vacuum gauge, and a vacuum partial pressure gauge; The atmosphere control device of the vacuum friction testing machine also includes: a first baffle valve, a second baffle valve, a turbomolecular pump, a third baffle valve, a plug valve, and a second thermal conductivity vacuum gauge; one end of the first baffle valve is used to connect to the vacuum chamber, and the other end is connected to the mechanical pump; one end of the second baffle valve is used to connect to the vacuum chamber, and the other end is connected to the atmosphere; one end of the plug valve is used to connect to the vacuum chamber, and the other end is connected to the turbomolecular pump; the turbomolecular pump is connected to the mechanical pump through the third baffle valve; the second thermal conductivity vacuum gauge is provided on the fourth branch, and along the direction of gas flow in the fourth branch, the second thermal conductivity vacuum gauge is provided upstream of the mechanical pump.

2. A vacuum friction testing machine atmosphere control method, characterized in that: The vacuum friction tester atmosphere control device according to claim 1 is used to control the humidity of the air atmosphere. The vacuum friction tester atmosphere control method includes the following steps: S120: Turn on the first thermal conductivity vacuum gauge, the mechanical pump, and the first baffle valve, and after the vacuum chamber is evacuated to a medium vacuum, turn off the first thermal conductivity vacuum gauge, the mechanical pump, and the first baffle valve; S131: Turn on the first humidity sensor and the first ball valve, and fully open the seventh throttle valve; S132: Open and adjust the pressure reducing valve on the compressed air circuit connected to the first air circuit and the second air circuit so that the pressure gauge on the compressed air circuit reads 0.1 MPa to 0.2 MPa; S133: Opening and adjusting the fifth throttle valve and the sixth throttle valve so that the reading of the first humidity sensor reaches a target humidity value; S140: Opening the first thermal conductivity vacuum gauge, the second ball valve, and the eighth throttle valve until the reading of the first thermal conductivity vacuum gauge reaches atmospheric pressure, then closing the first ball valve and opening the second baffle valve; S151: Turn on the second humidity sensor; S152: adjusting the opening and closing degrees of the fifth throttle valve and the sixth throttle valve according to the difference between the humidity target value and the reading of the second humidity sensor, so that the change in the reading of the first humidity sensor is equal to an iteration value; S153: Repeat step S152 until the reading of the second humidity sensor reaches the target humidity value.

3. A vacuum friction testing machine atmosphere control method, characterized in that: The vacuum friction tester atmosphere control device according to claim 1 is used to control the vacuum degree of different single gases. The vacuum friction tester atmosphere control method includes the following steps: S211: selecting any of the compressed gas circuits, and connecting an input end of the selected compressed gas circuit to a compressed gas source, wherein a single gas to be introduced into the vacuum chamber is used as the compressed gas in the compressed gas source; S212: Opening and adjusting the pressure reducing valve and the pressure gauge on the selected compressed air line so that the reading of the pressure gauge on the compressed air line is 0.1 MPa to 0.2 MPa; S220: Turning on the first thermal conductivity vacuum gauge, the mechanical pump, the first baffle valve, the second thermal conductivity vacuum gauge, and the third ball valve so that both the first thermal conductivity vacuum gauge and the second thermal conductivity vacuum gauge indicate medium vacuum. S230: Close the mechanical pump, the first baffle valve and the third ball valve, and open the throttle valve, the second ball valve and the eighth throttle valve on the selected compressed air path to inflate the vacuum chamber to a vacuum degree of 10 4 Pa magnitude; S240: Repeat steps S220 and S230 at least three times, then execute step S220 again, and then close the third ball valve; S250: Introducing compressed gas from the selected compressed gas circuit into the vacuum chamber to maintain the vacuum degree in the vacuum chamber at a target vacuum degree.

4. The vacuum friction testing machine atmosphere control method according to claim 3, characterized in that: The target vacuum degree is 10 5 Pa~10 3 Pa, the step S250 includes: S2511: Turn off the mechanical pump and the first baffle valve, and keep the first thermal conductivity vacuum gauge turned on; S2512: Open the throttle valve, the second ball valve and the eighth throttle valve on the selected compressed air circuit until the reading of the first thermal conductivity vacuum gauge reaches the target vacuum degree, and then close the second ball valve.

5. The vacuum friction testing machine atmosphere control method according to claim 3, characterized in that: The target vacuum degree is 10 3 Pa~10 1 Pa, the step S250 includes: S2521: Keep the first flapper valve, the mechanical pump, and the first thermal conductivity vacuum gauge open; S2522: Fully open the throttle valve on the selected compressed air circuit, open the second ball valve, open and adjust the eighth throttle valve until the vacuum degree in the vacuum chamber is dynamically balanced at the target vacuum degree.

6. The vacuum friction testing machine atmosphere control method according to claim 3, characterized in that: The target vacuum degree is 10 1 Pa~10 -1 Pa, the step S250 includes: S2531: Close the first baffle valve, keep the mechanical pump and the first thermal conductivity vacuum gauge open, open the third baffle valve, the plug valve, the turbomolecular pump, and the ionization vacuum gauge to evacuate the vacuum chamber to a vacuum degree of 10 -1 Below Pa; S2532: Fully open the throttle valve on the selected compressed air circuit, open and adjust the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches a dynamic balance at the target vacuum degree.

7. The vacuum friction testing machine atmosphere control method according to claim 3, characterized in that: The target vacuum degree is 10 -1 Pa~10 -3 Pa, the step S250 includes: S2541: Close the first baffle valve, wrap heating tape around the gas path where the mechanical pump, the third baffle valve, the gate valve, and the turbomolecular pump are located, and around the vacuum chamber, respectively, and heat the heating tape to above 120° C. In this heated state, keep the mechanical pump, the third baffle valve, the gate valve, and the turbomolecular pump open and running continuously for more than 48 hours; S2542: Keep the mechanical pump, the third flapper valve, the gate valve, the turbomolecular pump, and the first thermal conductivity vacuum gauge open, fully open the throttle valve on the selected compressed air path, and open and adjust the vacuum fine-tuning valve until the vacuum level in the vacuum chamber reaches a dynamic equilibrium at the target vacuum level. S2543: Turn on the vacuum pressure gauge and record the composition and proportion of the impurity gas in the vacuum chamber according to the reading of the vacuum pressure gauge.

8. A vacuum friction testing machine atmosphere control method, characterized in that: The vacuum friction tester atmosphere control device according to claim 1 is used to control the vacuum degree of volatile liquids with different saturated vapor pressures. The vacuum friction tester atmosphere control method includes the following steps: S310: placing a volatile liquid in the liquid container; S320: Opening the second thermal conductivity vacuum gauge, the mechanical pump, the third ball valve, and the seventh throttle valve to allow the mechanical pump to extract the gas generated by the volatilization of the volatile liquid. When the reading of the second thermal conductivity vacuum gauge stabilizes, closing the third ball valve. S330: Turn on the first thermal conductivity vacuum gauge, the mechanical pump, and the first baffle valve to evacuate the vacuum chamber to a medium vacuum; S340: Close the first baffle valve, open the third baffle valve, the plug valve, the turbomolecular pump and the ionization vacuum gauge to evacuate the vacuum chamber to a vacuum degree of 10 -1 Below Pa; S350: Open the second ball valve and the eighth throttle valve. When the reading of the first thermal conductivity vacuum gauge rises to 10 1 When the pressure is above 0.05 Pa, close the eighth throttle valve until the reading of the ionization vacuum gauge is 10 -1 Below Pa; S360: Repeat step S350 at least three times; S370: introducing the gas generated by the volatilization of the volatile liquid into the vacuum chamber to maintain the vacuum degree in the vacuum chamber at a target vacuum degree.

9. The vacuum friction testing machine atmosphere control method according to claim 8, characterized in that: The saturated vapor pressure of the volatile liquid is 10 3 The target vacuum degree is the saturated vapor pressure of the volatile liquid to 10 3 Pa, the step S370 includes: S3711: Close the third flapper valve, the plug valve, the turbomolecular pump, and the mechanical pump, and keep the first thermal conductivity vacuum gauge open; S3712: Open the seventh throttle valve, the second ball valve, and the eighth throttle valve until the reading of the first thermal conductivity vacuum gauge reaches the target vacuum degree, and then close the second ball valve.

10. The vacuum friction testing machine atmosphere control method according to claim 8, characterized in that: The saturated vapor pressure of the volatile liquid is 10 1 Above, the target vacuum degree is 10 3 Pa~10 1 Pa, the step S370 includes: S3721: Open the first baffle valve, keep the mechanical pump and the first thermal conductivity vacuum gauge turned on, and close the turbomolecular pump, the gate valve, and the third baffle valve; S3722: Open the seventh throttle valve and the second ball valve; open and adjust the eighth throttle valve until the vacuum degree in the vacuum chamber is dynamically balanced at the target vacuum degree.

11. The vacuum friction testing machine atmosphere control method according to claim 8, characterized in that: The saturated vapor pressure of the volatile liquid is 10 -1 Above, the target vacuum degree is 10 1 Pa~10 -1 Pa, the step S370 includes: S3731: Keep the mechanical pump, the third flapper valve, the gate valve, the turbomolecular pump, and the first thermal conductivity vacuum gauge turned on; S3732: Open the seventh throttle valve, open and adjust the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches a dynamic balance at the target vacuum degree.

12. The vacuum friction testing machine atmosphere control method according to claim 8, characterized in that: The saturated vapor pressure of the volatile liquid is 10 -3 Above, the target vacuum degree is 10 -1 Pa~10 -3 Pa, the step S370 includes: S3741: Wrap heating tapes around the gas path where the mechanical pump, the third flapper valve, the gate valve, and the turbomolecular pump are located, and the vacuum chamber, and heat the heating tapes to above 120° C. In this heated state, keep the mechanical pump, the third flapper valve, the gate valve, and the turbomolecular pump turned on and running continuously for at least 48 hours. S3742: Keep the mechanical pump, the third baffle valve, the plug valve, the turbomolecular pump, and the first thermal conductivity vacuum gauge open, open the seventh throttle valve, and open and adjust the vacuum fine-tuning valve until the vacuum level in the vacuum chamber reaches a dynamic equilibrium at the target vacuum level. S3743: Turn on the vacuum pressure gauge and record the composition and proportion of the impurity gas in the vacuum chamber according to the reading of the vacuum pressure gauge.

13. A vacuum friction testing machine atmosphere control method, characterized in that: The vacuum friction tester atmosphere control device according to claim 1 is used to control the normal pressure mixing of mixed gases of different proportions. The vacuum friction tester atmosphere control method includes the following steps: S411: Selecting a plurality of compressed gas circuits, wherein the plurality of compressed gas circuits correspond one-to-one to the types of gases to be mixed, and selecting a compressed gas source of the corresponding type as a compressed gas source connected to the selected compressed gas circuits; S412: Open and adjust the pressure reducing valves on the selected plurality of compressed air lines so that the pressure gauges on the plurality of compressed air lines read 0.1 MPa to 0.2 MPa; S420: Turn on the first thermal conductivity vacuum gauge, the second thermal conductivity vacuum gauge, the mechanical pump, the first baffle valve, and the third ball valve, so that the first thermal conductivity vacuum gauge indicates a medium vacuum, and then close the first baffle valve. S430 includes: S431: opening the throttle valve on one of the selected compressed air lines until the reading of the second thermal conductivity vacuum gauge rises to 10 4 When the pressure reaches the Pa level, close the throttle valve until the reading of the second thermal conductivity vacuum gauge drops to 10 2 Pa below; S432: after repeating step S431 at least three times, closing the third ball valve; S440: Opening the throttle valve, the second ball valve, and the eighth throttle valve on the compressed gas line in step S430 until the increase in the reading of the first thermal conductivity vacuum gauge reaches the partial pressure of the gas type corresponding to the compressed gas line, and then closing the second ball valve, the eighth throttle valve, and the throttle valve; S450: executing step S430 and step S440 multiple times, wherein the number of times step S430 and step S440 are executed is equal to the number of the selected multiple compressed air circuits, and the compressed air circuit opened each time step S430 and step S440 are executed is different from one another; S461: Turn on the gas concentration sensor. If the proportion of a certain gas is insufficient, repeat step S430, and select the compressed gas path corresponding to the certain gas in step S430; S462: opening the throttle valve, the second ball valve, and the eighth throttle valve on the compressed gas path corresponding to the certain gas to fill the vacuum chamber with the certain gas until the gas concentration sensor indicates that the proportion of the certain gas reaches a target proportion value, and then closing the second ball valve, the eighth throttle valve, and the throttle valve; S463: Open the first ball valve and the vacuum fine-tuning valve until the reading of the first thermal conductivity vacuum gauge drops to normal pressure, and then close the first ball valve and the vacuum fine-tuning valve.

14. A vacuum friction testing machine atmosphere control method, characterized in that: The vacuum friction tester atmosphere control device according to claim 1 is used to control the vacuum degree of mixed gases of different proportions. The vacuum friction tester atmosphere control method comprises the following steps: S510: Turn on the first thermal conductivity vacuum gauge, the mechanical pump, the first baffle valve, and the third ball valve, so that the first thermal conductivity vacuum gauge indicates a medium vacuum, and close the third ball valve and the first baffle valve. S520: Open the third flapper valve, the plug valve, the turbomolecular pump, and the ionization vacuum gauge to pump the vacuum chamber to a vacuum degree of 10 -1 Below Pa; S531: Selecting a plurality of compressed gas circuits, wherein the plurality of compressed gas circuits correspond one-to-one to the types of gases to be mixed, and selecting a compressed gas source of the corresponding type as the compressed gas source connected to the selected compressed gas circuits; S532: Open and adjust the pressure reducing valves on the selected plurality of compressed air lines so that the pressure gauges on the plurality of compressed air lines read 0.1 MPa to 0.2 MPa; S533: Opening the first ball valve and the throttle valves on the selected plurality of compressed air lines, so that the various types of gases corresponding to the selected plurality of compressed air lines are mixed and then discharged through the aggregate air line through the first ball valve; S541: Open the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches 10 -1 After the pressure drops below 0.1, turn on the vacuum pressure gauge; S542: adjusting the throttle valves on the selected plurality of compressed gas lines according to the partial pressure ratio of the gas monitored by the vacuum partial pressure gauge until the partial pressure ratio of the gas monitored by the vacuum partial pressure gauge reaches a target ratio value, and closing the vacuum fine-tuning valve; S550: Introducing gas from the selected plurality of compressed gas lines into the vacuum chamber to maintain the vacuum degree in the vacuum chamber at a target vacuum degree.

15. The vacuum friction testing machine atmosphere control method according to claim 14, characterized in that: The target vacuum degree is 10 5 Pa~10 3 Pa, the step S550 includes: S5511: Close the third flapper valve, the plug valve, the turbomolecular pump, and the mechanical pump; S5512: Open the second ball valve and the eighth throttle valve until the reading of the first thermal conductivity vacuum gauge reaches the target vacuum degree, and then close the second ball valve.

16. The vacuum friction testing machine atmosphere control method according to claim 14, characterized in that: The target vacuum degree is 10 3 Pa~10 1 Pa, the step S550 includes: S5521: Keep the mechanical pump and the first thermal conductivity vacuum gauge turned on, close the third flapper valve, the plug valve, and the turbomolecular pump, and open the first flapper valve; S5522: Open the second ball valve, open and adjust the eighth throttle valve until the vacuum degree in the vacuum chamber is dynamically balanced at the target vacuum degree.

17. The vacuum friction testing machine atmosphere control method according to claim 14, characterized in that: The target vacuum degree is 10 1 Pa~10 -1 Pa, the step S550 includes: S5531: Keep the mechanical pump, the third flapper valve, the gate valve, the turbomolecular pump, and the first thermal conductivity vacuum gauge turned on; S5532: Open and adjust the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches a dynamic balance at the target vacuum degree.

18. The vacuum friction testing machine atmosphere control method according to claim 14, characterized in that: The target vacuum degree is 10 -1 Pa~10 -3 Pa, the step S550 includes: S5541: Wrap heating tapes around the gas path where the mechanical pump, the third flapper valve, the gate valve, and the turbomolecular pump are located, and the vacuum chamber, and heat the heating tapes to above 120° C. In this heated state, keep the mechanical pump, the third flapper valve, the gate valve, and the turbomolecular pump turned on and running continuously for at least 48 hours. S5542: Keep the mechanical pump, the third flapper valve, the plug valve, the turbomolecular pump, and the first thermal conductivity vacuum gauge continuously turned on, and open and adjust the vacuum fine-tuning valve until the vacuum degree in the vacuum chamber reaches a dynamic equilibrium at the target vacuum degree; S5543: Vacuum pressure gauge monitoring: Turn on the vacuum pressure gauge and record the composition and proportion of the impurity gas in the vacuum chamber according to the reading of the vacuum pressure gauge.

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