Solenoid valve, solenoid valve assembly, mass flow controller, and electronic device

Abstract

The embodiment of the present application provides a kind of solenoid valve, solenoid valve assembly, mass flow controller and electronic equipment, solenoid valve, solenoid valve includes magnetic shell, magnetic column, magnetic valve core, valve nozzle, drive coil and detection coil, detection coil is connected in parallel with capacitor and forms resonance circuit, the first end of resonance circuit is electrically connected with controller by resistance, the second end of resonance circuit is grounded;Detection coil is used to receive the first current signal provided by controller to generate first magnetic field, to make the electromagnetic coupling between detection coil and magnetic valve core, so that the voltage value of first end is acquired by controller, to obtain the opening between magnetic valve core and valve nozzle by voltage value.Therefore, the solenoid valve, solenoid valve assembly, mass flow controller and electronic equipment provided by the embodiment of the present application can improve the control stability and response speed of solenoid valve, solenoid valve assembly, mass flow controller and electronic equipment to the mass flow of fluid.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromagnetic valves, and in particular to an electromagnetic valve, an electromagnetic valve assembly, a mass flow controller and an electronic device. BACKGROUND

[0002] A mass flow controller (MFC) can be used to measure and control the mass flow of a gas or a liquid.

[0003] In related technologies, a mass flow controller can include a gas channel, a mass flow sensor and an electromagnetic valve, the mass flow sensor and the electromagnetic valve are both arranged on the gas channel, the mass flow sensor is used to measure the mass flow of the gas in the gas channel, and the mass flow of the gas in the gas channel can be controlled by adjusting the opening of the electromagnetic valve.

[0004] However, the control stability of the above-mentioned electromagnetic valve on the mass flow of the gas is poor. SUMMARY

[0005] In view of at least one of the above technical problems, the embodiments of the present application provide an electromagnetic valve, an electromagnetic valve assembly, a mass flow controller and an electronic device, which can improve the control stability of the electromagnetic valve and the mass flow controller on the mass flow of the fluid.

[0006] The embodiments of the present application provide the following technical solutions:

[0007] The first aspect of the embodiments of the present application provides an electromagnetic valve for working under the control of a controller assembly, the controller assembly including a controller, a resistor and a capacitor, the controller being electrically connected with the resistor, the electromagnetic valve including a magnetically conductive shell, a magnetically conductive column, a magnetically conductive valve core, a valve nozzle, a driving coil and a detection coil, the magnetically conductive shell having a containing cavity therein, the magnetically conductive column, the magnetically conductive valve core, the valve nozzle, the driving coil and the detection coil all being located in the containing cavity, the magnetically conductive column, the magnetically conductive valve core and the valve nozzle being arranged in sequence along a first direction, the magnetically conductive column being connected with the magnetically conductive shell, the magnetically conductive valve core being movably connected with the valve nozzle along the first direction, and the valve nozzle being provided with a flow channel; wherein the detection coil is located on a side of the magnetically conductive column facing the magnetically conductive valve core, the detection coil is connected in parallel with the capacitor to form a resonance circuit, a first end of the resonance circuit is electrically connected with the controller through the resistor, and a second end of the resonance circuit is grounded; the detection coil is used to receive a first current signal provided by the controller to generate a first magnetic field, so as to electromagnetically couple between the detection coil and the magnetically conductive valve core, thereby enabling the controller to obtain a voltage value of the first end to obtain the opening between the magnetically conductive valve core and the valve nozzle through the voltage value.

[0008] The electromagnetic valve provided by the embodiment of the present application forms a resonance circuit by connecting a detection coil and a capacitor in parallel, a first end of the resonance circuit is electrically connected to a controller through a resistor, and a second end of the resonance circuit is grounded; the detection coil is used to receive a first current signal provided by the controller to generate a first magnetic field, so that the detection coil and the magnetically conductive spool are electromagnetically coupled, thereby enabling the controller to obtain a voltage value of the first end to obtain the opening degree between the magnetically conductive spool and the valve nozzle through the voltage value. Since there is a good corresponding relationship between the mass flow of the fluid and the opening degree, the target opening degree required can be determined according to the target mass flow required, and the opening degree of the electromagnetic valve is adjusted and controlled according to the difference between the actual opening degree detected and the target opening degree, until the difference between the actual opening degree detected and the target opening degree is less than the precision allowable value, thereby realizing the control of the opening degree and further realizing the control of the mass flow. In addition, the frequency of the first current signal provided to the detection coil can be adjusted according to the requirements, so as to make the obtained opening degree result more accurate. The detection coil is excited by the first current signal input actively, so that the anti-interference ability of the detection coil is stronger.

[0009] In a possible implementation, the surface of the magnetically conductive spool on the side facing the magnetically conductive column is a non-metal surface, or the surface of the magnetically conductive spool on the side facing the magnetically conductive column is a metal surface. In this way, the magnetically conductive spool can be arranged in more ways, and can be applied to more scenes.

[0010] In a possible implementation, the electromagnetic valve comprises a non-magnetic isolation piece, the isolation piece separates the accommodation cavity into a first accommodation cavity and a second accommodation cavity, the magnetically conductive column, the driving coil and the detection coil are located in the first accommodation cavity, and the magnetically conductive spool and the valve nozzle are located in the second accommodation cavity. In this way, by arranging the isolation piece, the fluid can be prevented from entering the first accommodation cavity from the second accommodation cavity, the detection coil is physically isolated from the magnetically conductive spool through the isolation piece, and the detection coil will not be in contact with the magnetically conductive spool through the fluid, thereby preventing the fluid from adversely affecting the structural parts located in the first accommodation cavity.

[0011] In a possible implementation, the material of the isolation piece comprises a metal material; the thickness of the isolation piece is less than or equal to 2 mm; and / or the frequency range of the first current signal is 10 KHZ-100 KHZ. In this way, the frequency range of the first current signal is 10 KHZ-100 KHZ, so that the first magnetic field is more easily penetrated through the metal isolation piece, which is beneficial to reducing the influence of the isolation piece on the first magnetic field. The thickness of the isolation piece can be set to be smaller, and the smaller the thickness of the isolation piece, the greater the electromagnetic force provided.

[0012] In a possible implementation, the material of the isolation piece comprises a non-metal material, and the frequency of the first current signal is greater than or equal to 100 KHZ. In this way, when the isolation piece is made of a non-metal material, the frequency range of the first current signal is wider, and the isolation piece can be applied to more scenes.

[0013] In a possible implementation, the material of the isolation member comprises a corrosion-resistant material; and / or, the material of the magnetically conductive spool comprises a corrosion-resistant material. In this way, the isolation member and / or the magnetically conductive spool can be prevented from being corroded by the fluid, and the isolation effect of the isolation member can be improved.

[0014] In a possible implementation, the detection coil has a first distance from the magnetically conductive spool when the electromagnetic valve is in the closed state, and has a second distance from the magnetically conductive spool when the electromagnetic valve is in the open state, and the opening degree is equal to the difference between the first distance and the second distance.

[0015] In a possible implementation, the driving coil is sleeved on the outer periphery of the magnetically conductive column, and the controller is electrically connected to the driving coil. When the electromagnetic valve is in the open state, the controller is configured to provide a second current signal to the driving coil to generate a second magnetic field, and the second magnetic field acts on the magnetically conductive spool to cause the magnetically conductive spool to be subjected to a magnetic force in the first direction. In this way, under the action of the magnetic force, the magnetically conductive spool moves towards or away from the driving coil, thereby changing the gap between the magnetically conductive spool and the valve nozzle, i.e., changing the opening degree between the magnetically conductive spool and the valve nozzle, to control the mass flow rate of the fluid between the magnetically conductive spool and the valve nozzle.

[0016] In a possible implementation, the electromagnetic valve comprises an elastic member, one end of the elastic member is connected to the valve nozzle, and the other end of the elastic member is connected to the magnetically conductive spool. The elastic member is configured to provide an elastic force towards the valve nozzle to the magnetically conductive spool. In this way, the elastic member can be used to provide an elastic force towards the valve nozzle to the magnetically conductive spool. When the electromagnetic valve is switched from the open state to the closed state, the driving coil has no second current signal, and the magnetically conductive spool moves towards the valve nozzle under the action of the elastic member, so that the magnetically conductive spool contacts the valve nozzle to close the flow passage of the valve nozzle.

[0017] In a possible implementation, the magnetically conductive column has a groove on the side facing the magnetically conductive spool, and the detection coil is located in the groove. In this way, the groove can limit the detection coil, and also helps to reduce the overall volume of the magnetically conductive column and the detection coil.

[0018] A second aspect of the embodiment of the present application provides an electromagnetic valve assembly, comprising a controller assembly and the electromagnetic valve in the first aspect, and the controller assembly and the electromagnetic valve are electrically connected.

[0019] The electromagnetic valve assembly provided by the embodiment of the application comprises an electromagnetic valve, a detection coil and a capacitor are connected in parallel to form a resonance circuit, a first end of the resonance circuit is electrically connected to a controller through a resistor, and a second end of the resonance circuit is grounded; the detection coil is used to receive a first current signal provided by the controller to generate a first magnetic field, so that the detection coil and a magnetically conductive valve core are electromagnetically coupled, so that the controller obtains a voltage value of the first end, and the opening degree between the magnetically conductive valve core and a valve nozzle is obtained through the voltage value; since there is a good corresponding relationship between the mass flow of the fluid and the opening degree, the target opening degree required can be determined according to the target mass flow required, and the opening degree of the electromagnetic valve is adjusted and controlled according to the difference between the actual opening degree detected and the target opening degree, until the difference between the actual opening degree detected and the target opening degree is less than a precision allowable value, so that the control of the opening degree is realized, and the control of the mass flow is realized in turn. In addition, the frequency of the first current signal provided to the detection coil can be adjusted according to requirements, so as to make the obtained opening degree result more accurate, and the detection coil is excited by the first current signal actively input, so that the anti-interference ability of the detection coil is stronger.

[0020] The third aspect of the embodiment of the application provides a mass flow controller, comprising a controller assembly, a fluid channel, a mass flow sensor and the electromagnetic valve of the first aspect, the controller assembly is electrically connected to the mass flow sensor and the electromagnetic valve, and the mass flow sensor is used to measure the mass flow of the fluid in the fluid channel.

[0021] The mass flow controller provided by the embodiment of the application comprises an electromagnetic valve, a detection coil and a capacitor are connected in parallel to form a resonance circuit, a first end of the resonance circuit is electrically connected to a controller through a resistor, and a second end of the resonance circuit is grounded; the detection coil is used to receive a first current signal provided by the controller to generate a first magnetic field, so that the detection coil and a magnetically conductive valve core are electromagnetically coupled, so that the controller obtains a voltage value of the first end, and the opening degree between the magnetically conductive valve core and a valve nozzle is obtained through the voltage value; since there is a good corresponding relationship between the mass flow of the fluid and the opening degree, the target opening degree required can be determined according to the target mass flow required, and the opening degree of the electromagnetic valve is adjusted and controlled according to the difference between the actual opening degree detected and the target opening degree, until the difference between the actual opening degree detected and the target opening degree is less than a precision allowable value, so that the control of the opening degree is realized, and the control of the mass flow is realized in turn. In addition, the frequency of the first current signal provided to the detection coil can be adjusted according to requirements, so as to make the obtained opening degree result more accurate, and the detection coil is excited by the first current signal actively input, so that the anti-interference ability of the detection coil is stronger.

[0022] In a possible implementation, the controller component is configured to look up the opening degree of the electromagnetic valve in a first relationship table indexed by the mass flow rate, the first relationship table storing a pre-calibrated corresponding relationship between the mass flow rate and the opening degree, and adjust the opening degree of the electromagnetic valve according to the looked-up opening degree.

[0023] In this way, the control stability of the electromagnetic valve and the mass flow rate controller on the mass flow rate of the fluid can be improved due to the fast response speed of the resonant circuit output.

[0024] In a possible implementation, the controller component is configured to look up the second current signal of the electromagnetic valve in a second relationship table indexed by the opening degree of the electromagnetic valve, the second relationship table storing a pre-calibrated corresponding relationship between the opening degree and the second current signal, and adjust the opening degree of the electromagnetic valve according to the looked-up second current signal.

[0025] In this way, according to the required target opening degree, the approximate target second current signal of the electromagnetic valve can be looked up in the second relationship table, the approximate target second current signal is relatively close to the target current signal, the speed of adjusting the approximate target second current signal to the target second current signal is fast when the opening degree of the electromagnetic valve is controlled by the second current signal, so that the closed-loop control response time of the valve core target opening degree can be further reduced, and the control stability of the electromagnetic valve and the mass flow rate controller on the mass flow rate of the fluid can be further improved.

[0026] The fourth aspect of the embodiments of the present application provides an electronic device including the mass flow rate controller of the third aspect.

[0027] The electronic device provided by the embodiments of the present application includes the mass flow rate controller, the detection coil and the capacitor are connected in parallel to form a resonant circuit, the first end of the resonant circuit is electrically connected to the controller through the resistor, and the second end of the resonant circuit is grounded; the detection coil is used to receive the first current signal provided by the controller to generate a first magnetic field, so that the detection coil and the magnetically conductive valve core are electromagnetically coupled, so that the controller obtains the voltage value of the first end to obtain the opening degree between the magnetically conductive valve core and the valve nozzle, and since the mass flow rate of the fluid and the opening degree have a good corresponding relationship, the required target opening degree can be determined according to the required target mass flow rate, and the opening degree of the electromagnetic valve is adjusted and controlled according to the difference between the detected actual opening degree and the target opening degree until the difference between the detected actual opening degree and the target opening degree is less than the precision allowable value, so as to realize the control of the opening degree and further realize the control of the mass flow rate. In addition, the frequency of the first current signal provided to the detection coil can be adjusted according to the requirement, so as to make the obtained opening degree result more accurate, and the detection coil is excited by the actively input first current signal, so that the anti-interference ability of the detection coil is stronger. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0029] Figure 1 The structural schematic diagram of MFC provided for the embodiments of the present application is shown in the figure.

[0030] Figure 2 Another structural schematic diagram of MFC provided for the embodiments of the present application is shown in the figure.

[0031] Figure 3 Another structural schematic diagram of MFC provided for the embodiments of the present application is shown in the figure.

[0032] Figure 4 The structural schematic diagram of detection coil and signal conditioning and control module provided for the embodiments of the present application is shown in the figure.

[0033] Figure 5 The structural schematic diagram of resonant circuit and resistance provided for the embodiments of the present application is shown in the figure.

[0034] Figure 6 The structural schematic diagram of electromagnetic valve assembly provided for the embodiments of the present application is shown in the figure.

[0035] Figure 7 The partial enlarged structural schematic diagram of electromagnetic valve provided for the embodiments of the present application is shown in the figure.

[0036] Figure 8 The structural schematic diagram of detection coil and magnetic conducting valve core provided for the embodiments of the present application is shown in the figure.

[0037] Figure 9 Another structural schematic diagram of detection coil and magnetic conducting valve core provided for the embodiments of the present application is shown in the figure.

[0038] Figure 10 The relationship diagram of collected and processed voltage signal and opening degree provided for the embodiments of the present application is shown in the figure.

[0039] Figure 11 The top view of detection coil provided for the embodiments of the present application is shown in the figure.

[0040] Figure 12 The structural schematic diagram of detection coil, isolation member and magnetic conducting valve core provided for the embodiments of the present application is shown in the figure.

[0041] Explanation of reference signs:

[0042] 100-mass flow controller; 101-mass flow sensor;

[0043] 102 - fluid channel; 1021 - detection channel;

[0044] 1022 - shunt channel; 103 - inlet;

[0045] 104 - outlet; 105 - electromagnetic valve assembly;

[0046] 110 - control board; 111 - first control module;

[0047] 112 - second control module; 113 - drive module;

[0048] 114 - signal conditioning module; 115 - flow calculation module;

[0049] 116 - signal conditioning and control module; 1161 - signal amplification unit;

[0050] 1162 - signal detection unit; 1163 - signal sampling and analysis processing unit;

[0051] 117 - resonant circuit; 120 - electromagnetic valve;

[0052] 121 - magnetically conductive housing; 1211 - first magnetically conductive housing;

[0053] 1212 - second magnetically conductive housing; 122 - magnetically conductive column;

[0054] 123 - magnetically conductive valve core; 124 - elastic member;

[0055] 125 - valve nozzle; 1253 - third flow channel;

[0056] 1254 - fourth flow channel; 126 - drive coil;

[0057] 127 - detection coil; 128 - through-flow member;

[0058] 1281 - first flow channel; 1282 - second flow channel;

[0059] 129 - isolation member. DETAILED DESCRIPTION

[0060] In the related art, a mass flow controller can include a gas channel, a mass flow sensor, and an electromagnetic valve, the mass flow sensor and the electromagnetic valve are both arranged on the gas channel, the mass flow sensor is used to measure the mass flow of the gas in the gas channel, and the mass flow of the gas in the gas channel can be controlled by adjusting the opening degree of the electromagnetic valve.

[0061] The electromagnetic valve comprises a magnetically conductive shell having a receiving cavity, a drive coil, a magnetically conductive core, a magnetically conductive valve core and a gas nozzle located in the receiving cavity, the magnetically conductive core is connected with the magnetically conductive shell, and the drive coil is arranged around the magnetically conductive core. The magnetically conductive valve core is located between the gas nozzle and the magnetically conductive core, and the magnetically conductive valve core and the gas nozzle are connected through a spring. The size of the electromagnetic attraction of the drive coil to the magnetically conductive valve core can be changed by changing the current in the drive coil, so as to change the opening size between the magnetically conductive valve core and the gas nozzle, thereby controlling the gas mass flow by controlling the opening size.

[0062] However, the drive coil needs a strong magnetic field to drive the magnetically conductive valve core to move, so a closed-loop magnetic circuit needs to be constructed with a magnetically conductive material. Under the influence of the magnetically conductive material inside and outside the drive coil, the drive coil will have a magnetic hysteresis phenomenon when generating a magnetic field. Due to the above magnetic hysteresis effect of the electromagnetic valve, the difference in physical properties of different gases, the input gas pressure, the environmental temperature and other factors, the opening between the magnetically conductive valve core and the gas nozzle and the current in the drive coil do not have a good linear relationship, and a direct relationship cannot be established between the current of the drive coil and the opening of the valve core, so that fast valve core opening control cannot be realized, and the mass flow of the gas cannot be quickly and accurately controlled. For example, a thermal mass flow sensor can be used to detect the mass flow of the gas (i.e. the actual mass flow). When different mass flows of gas flow through the capillary tube of the thermal mass flow sensor, different amounts of heat can be carried away, the resistance value of the resistance wire of the thermal mass flow sensor changes, and through the signal conditioning circuit and software processing, the mass flow of the gas flowing through can be obtained. According to the difference between the actual mass flow and the target mass flow, the opening of the electromagnetic valve is controlled by a proportional-integral-derivative control (PID) algorithm until the difference between the actual mass flow and the target mass flow is less than the precision allowed value, thereby realizing the control of the mass flow. However, during the measurement process of the thermal mass flow sensor, the resistance value of the resistance wire changes by heating the resistance wire with current and the gas carrying away the heat on the resistance wire, and the change of the heat to the temperature stabilization is a slow process, which requires a long time, so the response speed of the thermal mass flow sensor is slow, which brings great challenges to the fast real-time control of the mass flow of the electromagnetic valve, and the control stability of the mass flow of the electromagnetic valve is poor.

[0063] To solve at least one of the above technical problems, the present application provides an electromagnetic valve, an electromagnetic valve assembly, a mass flow controller and an electronic device. A detection coil is connected in parallel with a capacitor to form a resonance circuit. A first end of the resonance circuit is electrically connected to a controller through a resistor, and a second end of the resonance circuit is grounded. The detection coil is configured to receive a first current signal provided by the controller to generate a first magnetic field, so that the detection coil and a magnetically conductive spool are electromagnetically coupled. Thus, the controller can obtain a voltage value of the first end, and can obtain an opening degree between the magnetically conductive spool and a valve nozzle based on the voltage value. Since the mass flow of the fluid has a good corresponding relationship with the opening degree, the target opening degree can be determined according to the target mass flow. The opening degree of the electromagnetic valve can be adjusted and controlled according to the difference between the actual opening degree and the target opening degree until the difference between the actual opening degree and the target opening degree is less than a precision allowable value. Thus, the opening degree can be controlled, and the mass flow can be controlled. In addition, the frequency of the first current signal provided to the detection coil can be adjusted according to requirements, so that the obtained opening degree result is more accurate. The detection coil is excited by the actively input first current signal, so that the anti-interference ability of the detection coil is strong.

[0064] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0065] The technical solutions in the embodiments of the present application will be described below with reference to the drawings. Figures 1-12 The electromagnetic valve, the electromagnetic valve assembly, the mass flow controller and the electronic device provided by the embodiments of the present application will be described.

[0066] The present application provides a mass flow controller 100, which can be used to control the mass flow of a fluid. The fluid can include gas, liquid, etc. For example, the mass flow controller 100 can be applied to the semiconductor industry.

[0067] Referring to Figure 1 and Figure 2, the mass flow controller 100 can include a fluid channel 102, a mass flow sensor 101 (e.g., a thermal mass flow sensor), a solenoid valve 120, and a controller assembly including a controller, a capacitor, and a resistor. For example, the controller assembly can be a control board 110. The solenoid valve 120 and the control board 110 can be electrically connected, and the solenoid valve 120 and the control board 110 can jointly form a solenoid valve assembly 105. The control board 110 and the mass flow sensor 101 are electrically connected. The mass flow sensor 101 is used to measure the mass flow of the fluid in the fluid channel 102, and the solenoid valve 120 can control the mass flow of the fluid in the fluid channel 102.

[0068] For example, referring to Figure 1 and Figure 2 , the control board 110 can include a controller, and the controller can include a first control module 111, a driving module 113, a signal conditioning module 114, and a flow calculation module 115, wherein the mass flow sensor 101 and the first control module 111 are electrically connected through the signal conditioning module 114 and the flow calculation module 115. The solenoid valve 120 and the first control module 111 are electrically connected through the driving module 113. For example, the first control module 111 can be a PID control module.

[0069] For example, referring to Figure 1 and Figure 2 , the two ends of the fluid channel 102 are in communication with an outlet 104 and an inlet 103, respectively. The mass flow sensor 101 can be disposed close to the inlet 103, and the solenoid valve 120 can be disposed close to the outlet 104. The fluid channel 102 and the outlet 104 can be in communication through the solenoid valve 120. The fluid enters a detection channel 1021 and a flow divider channel 1022 of the fluid channel 102 from the inlet 103, and the actual mass flow of the fluid can be measured by the mass flow sensor 101. The flow signal output by the mass flow sensor 101 is sent to the flow calculation module 115 in the control board 110 after passing through the signal conditioning module 114 for real-time flow calculation. The calculated flow is sent to the first control module 111 in the control board 110. The first control module 111 determines the opening state of the solenoid valve 120 by detecting the difference between the actual mass flow and the target mass flow, and inputs an appropriate driving signal (i.e., a second current signal) to the solenoid valve 120 through the driving module 113 to open the solenoid valve 120 to the appropriate opening until the measured actual mass flow is consistent with the target mass flow.

[0070] For example, the solenoid valve 120 includes an opening detector, which can be used to detect the position of the magnetically conductive valve core 123 and the valve nozzle 125 Figure 7) between the opening degree and the mass flow rate of the fluid. In this way, since there is a good corresponding relationship between the mass flow rate of the fluid and the opening degree, the target opening degree required can be determined according to the target mass flow rate required, and the difference between the actual opening degree detected by the opening degree detector and the target opening degree is used to adjust and control the opening degree of the electromagnetic valve 120 until the difference between the actual opening degree detected and the target opening degree is less than the precision allowed value, thereby achieving control of the opening degree and further achieving control of the mass flow rate. Since the opening degree detector has a fast response speed, the control stability of the mass flow rate of the fluid by the electromagnetic valve 120 and the mass flow rate controller 100 can be improved. In addition, in order to ensure the accuracy of the mass flow rate control, the control board 110 also performs mass flow rate prediction through the mass flow rate value detected by the mass flow rate sensor 101, and uses the predicted mass flow rate to perform correction control of the electromagnetic valve 120, so as to improve the accuracy of the mass flow rate control, solve the problem of poor control accuracy in different fluid scenarios, and meet the requirements of ultra-high-precision mass flow rate control scenarios. That is, the opening degree is detected in real time by the opening degree detector to achieve fast closed-loop control of the mass flow rate of the MFC gas, and the mass flow rate sensor 101 can be used to achieve fast and accurate closed-loop control of the mass flow rate of the fluid.

[0071] For example, in the case where the type of gas, pressure, and temperature conditions are known, the mass flow rate of the fluid and the opening degree can have a good corresponding relationship. Of course, the mass flow rate of the fluid and the opening degree can have a good corresponding relationship in other cases, which is not limited by the present application.

[0072] For example, the mass flow rate controller 100 can include a temperature sensor, which can be used to measure the temperature of the fluid. The temperature sensor can be electrically connected to the controller of the control board 110.

[0073] For example, the mass flow rate controller 100 can include a pressure sensor, which can be used to measure the pressure of the fluid. The pressure sensor can be electrically connected to the controller of the control board 110.

[0074] For example, the controller of the control board 110 is configured to index the mass flow rate, and the first relationship table (e.g., the first relationship table 200) is configured to index the mass flow rate. Figure 3The opening degree of solenoid valve 120 is searched in the first relationship table, which stores a pre-calibrated correspondence between mass flow rate and opening degree. The opening degree of the solenoid valve is adjusted according to the searched opening degree. For example, the target opening degree of solenoid valve 120 can be searched in the first relationship table according to the required target mass flow rate. Then, based on the difference between the actual opening degree detected by the opening degree detector and the target opening degree, the second current signal (i.e., the drive signal) is adjusted to control the opening degree of solenoid valve 120 until the difference between the detected actual opening degree and the target opening degree is less than the accuracy allowable value, thereby realizing the control of the opening degree and thus the control of the mass flow rate. With this setting, the control stability of the mass flow rate of the fluid by solenoid valve 120 and mass flow controller 100 can be improved because the output response speed of the resonant circuit is fast.

[0075] The first relationship table can be stored in the memory of the control board 110. The first relationship tables can be different for different fluids, pressures, and temperatures; multiple first relationship tables can be established. In the embodiment equipped with the mass flow sensor 101, the target opening degree of the solenoid valve 120 can be corrected using the predicted mass flow rate, thereby improving the control accuracy of the mass flow rate.

[0076] For example, the controller of control panel 110 is configured to be indexed by the opening degree of solenoid valve 120 in a second relation table ( Figure 3 The second current signal (i.e., drive signal) of solenoid valve 120 is searched in the second relationship table. A pre-calibrated correspondence between the opening degree and the second current signal is stored in the second relationship table. The opening degree of the solenoid valve is adjusted according to the searched second current signal. The correspondence between the opening degree and the second current signal in the second relationship table is an approximate correspondence obtained without considering hysteresis. For example, based on the desired target opening degree, the approximate target second current signal of solenoid valve 120 can be searched in the second relationship table. Since the approximate target second current signal is close to the target current signal, the approximate target second current signal can be adjusted to the target second current signal more quickly when controlling the opening degree of solenoid valve 120 using the second current signal. This further reduces the closed-loop control response time of the valve core to the target opening degree and further improves the control stability of the mass flow rate of the fluid by solenoid valve 120 and mass flow controller 100. The second relationship table can be stored in the memory of control board 110.

[0077] It can be understood that the embodiment of the present application can establish the first relationship table, or can simultaneously establish the first relationship table and the second relationship table. In the embodiment of simultaneously establishing the first relationship table and the second relationship table, the two kinds of relationship tables can be stored in the memory of the control board 110. When the mass flow controller 100 needs to control the mass flow of the fluid, the control board 110 detects the opening degree between the magnetic conductive valve core 123 and the valve nozzle 125 in real time, and queries the above two kinds of relationship tables, so as to quickly close-loop control the mass flow of the fluid.

[0078] The electromagnetic valve 120 provided by the embodiment of the present application is described in detail below.

[0079] Referring to Figure 6 and Figure 7 , the electromagnetic valve 120 can include a magnetic conductive shell 121, a magnetic conductive column 122, a magnetic conductive valve core 123, a valve nozzle 125 and a driving coil 126. The magnetic conductive shell 121 has a containing cavity therein, and the magnetic conductive column 122, the magnetic conductive valve core 123, the valve nozzle 125, the driving coil 126 and at least part of the opening degree detector are located in the containing cavity. For example, the magnetic conductive column 122, the magnetic conductive valve core 123 and the valve nozzle 125 can be arranged in sequence along a first direction A, one end of the magnetic conductive column 122 away from the magnetic conductive valve core 123 is connected with the magnetic conductive shell 121, the magnetic conductive valve core 123 is movably connected to the valve nozzle 125 along the first direction A, and the valve nozzle 125 is provided with a flow channel (a third flow channel 1253 and / or a fourth flow channel 1254), for example, the flow channel can penetrate through the valve nozzle 125 along the first direction A. The driving coil 126 can be sleeved on the outer periphery of the magnetic conductive column 122.

[0080] For example, the electromagnetic valve 120 is electrically connected with the control board 110. The controller of the control board 110 is electrically connected with the driving coil 126. When the electromagnetic valve 120 is in an open state, the control board 110 is configured to provide a second current signal to the driving coil 126, the second current signal is passed into the driving coil 126 to generate a second magnetic field, the second magnetic field acts on the magnetic conductive valve core 123, so that the magnetic conductive valve core 123 is subjected to a magnetic force along the first direction A, for example, the magnetic conductive valve core 123 is subjected to a magnetic force towards the driving coil 126, or the magnetic conductive valve core 123 is subjected to a magnetic force away from the driving coil 126. The embodiment of the present application takes the magnetic conductive valve core 123 subjected to the magnetic force towards the driving coil 126 as an example for description, which can make the magnetic conductive valve core 123 move towards the direction away from the valve nozzle 125, so that the distance between the magnetic conductive valve core 123 and the valve nozzle 125 changes. When the electromagnetic valve 120 is in a closed state, the flow channel mouth of the flow channel of the valve nozzle 125 towards the side of the magnetic conductive valve core 123 is covered and closed by the magnetic conductive valve core 123.

[0081] For example, referring to Figure 6 and Figure 7When the electromagnetic valve 120 is in the open state, the second magnetic field passes through the magnetic conducting column 122, the detection coil 127, the isolation piece 129, the air gap between the isolation piece 129 and the magnetic conducting spool 123, the magnetic conducting spool 123, and the magnetic conducting housing 121 to form a closed magnetic circuit. Through the closed second magnetic field, the driving coil 126 generates an electromagnetic attraction force on the magnetic conducting spool 123, and the size of the electromagnetic attraction force is proportional to the second current signal passing through the driving coil 126. Under the action of the electromagnetic attraction force, the magnetic conducting spool 123 moves towards the driving coil 126, thereby changing the gap between the magnetic conducting spool 123 and the valve nozzle 125, i.e. changing the opening degree between the magnetic conducting spool 123 and the valve nozzle 125, to control the mass flow of fluid between the magnetic conducting spool 123 and the valve nozzle 125.

[0082] For example, referring to Figure 2 and Figure 6 , the magnetic conducting housing 121 can include a first magnetic conducting housing 1211 and a second magnetic conducting housing 1212, and the second magnetic conducting housing 1212 is located in the first magnetic conducting housing 1211. The second magnetic conducting housing 1212 is arranged close to the magnetic conducting spool 123. The magnetic conducting housing 121 has an opening that is in communication with the accommodating cavity, and the opening is arranged close to the valve nozzle 125. The opening is provided with a flow passage piece 128, and the fluid passage 102 is in communication with the electromagnetic valve 120 through the flow passage piece 128. The flow passage piece 128 has a first flow channel 1281 and a second flow channel 1282. The flow channel of the valve nozzle 125 includes a third flow channel 1253 and a fourth flow channel 1254, and the first flow channel 1281 is in communication with the third flow channel 1253 close to one end of the valve nozzle 125. The second flow channel 1282 is in communication with the fourth flow channel 1254 close to one end of the valve nozzle 125. Taking the fluid entering through the first flow channel 1281 as an example, the fluid passes through the first flow channel 1281, the third flow channel 1253, the gap between the magnetic conducting spool 123 and the valve nozzle 125, the fourth flow channel 1254, and the second flow channel 1282 in sequence. For example, the third flow channel 1253 can be an annular flow channel arranged outside the fourth flow channel 1254.

[0083] In some embodiments, referring to Figure 6 and Figure 7The electromagnetic valve 120 can include an elastic member 124, for example, the elastic member 124 can be a metal spring. The elastic member 124 can be annular. One end of the elastic member 124 is connected to the valve nozzle 125, and the other end of the elastic member 124 is connected to the magnetic conductive valve core 123, and the magnetic conductive valve core 123 is movably connected to the valve nozzle 125 through the elastic member 124. For example, one end of the elastic member 124 is pressed and fixed between the second magnetic conductive shell 1212 and the valve nozzle 125, and the other end of the elastic member 124 is connected to the magnetic conductive valve core 123. When the driving coil 126 passes through the second current signal, the magnetic conductive valve core 123 drives the elastic member 124 to produce a deformation tending to the direction of the driving coil 126, thereby changing the opening degree between the magnetic conductive valve core 123 and the valve nozzle 125. The elastic member 124 can be used to provide the magnetic conductive valve core 123 with an elastic force towards the valve nozzle 125. When the electromagnetic valve 120 is switched from the open state to the closed state, the driving coil 126 has no second current signal, and the magnetic conductive valve core 123 moves towards the valve nozzle 125 under the action of the elastic member 124, so that the magnetic conductive valve core 123 contacts the valve nozzle 125 to close the flow passage of the valve nozzle 125. For example, when the electromagnetic valve 120 is in the closed state, the magnetic conductive valve core 123 covers the fourth flow passage 1254, and the magnetic conductive valve core 123 covers the third flow passage 1253 through the elastic member 124.

[0084] The opening degree detector provided by the application embodiment is described in detail below.

[0085] Participate Figure 6 And Figure 7 The opening degree detector can include at least one detection coil 127, which is located in the accommodation cavity and on the side of the magnetic conductive column 122 facing the magnetic conductive valve core 123. The control panel 110 is electrically connected to the detection coil 127, and the controller of the control panel 110 is configured to provide a first current signal to the detection coil 127, and the first current signal in the detection coil 127 is used to generate a first magnetic field. The detection coil 127 and the magnetic conductive valve core 123 are electromagnetically coupled, and the controller of the control panel 110 is configured to obtain the inductance value of the detection coil 127. The change of the inductance value has good monotonic correlation with the distance between the magnetic conductive valve core 123 and the detection coil 127, and the detection of the opening degree between the magnetic conductive valve core 123 and the valve nozzle 125 can be realized through calibration.

[0086] For example, the controller of the control panel 110 is configured to use the inductance value as an index to find the opening degree of the electromagnetic valve 120 in the third relationship table, and the third relationship table stores the corresponding relationship between the opening degree and the inductance value calibrated in advance. Participate Figure 8When the electromagnetic valve 120 is in the closed state, the detection coil 127 has a first distance H1 from the magnetically conductive valve core 123, and when the electromagnetic valve 120 is in the open state, the detection coil 127 has a second distance H2 from the magnetically conductive valve core 123. The displacement AH of the magnetically conductive valve core 123 can be equal to the difference between the first distance H1 and the second distance H2, that is, AH = H1-H2, wherein the displacement AH can be the opening degree. For example, the controller of the control panel 110 detects the inductance value (equivalent to the output signal of the detection coil 127 in the third relationship table) of the detection coil 127 in real time, and finds the real-time opening degree of the electromagnetic valve 120 in the third relationship table according to the obtained inductance value, that is, the opening degree is detected. Figure 2

[0087] For example, the displacement AH of the magnetically conductive valve core 123 changes, causing the inductance value of the detection coil 127 to change, and the inductance value of the detection coil 127 changes, causing the voltage value output by the first end of the resonant circuit to change. The displacement AH of the magnetically conductive valve core 123 can be obtained by the change of the voltage value. The controller of the control panel 110 can include a second control module 112 ( Figure 3 ) and a signal conditioning and control module 116 ( Figure 6 ). The second control module 112 is electrically connected to the detection coil 127 through the signal conditioning and control module 116. Referring to Figure 4 and Figure 5 , the second control module 112 is configured to provide a first current signal to the electromagnetic valve 120, and the signal conditioning and control module 116 detects the voltage change caused by the change of the inductance value. The software can calculate the inductance value according to the voltage value detected by the signal conditioning and control module 116, and obtain the opening degree by the inductance value. For example, the voltage signal is processed by the signal amplification unit 1161, the signal detection unit 1162, and the signal sampling and analysis processing unit 1163 in the signal conditioning and control module 116 to obtain the inductance value. The controller assembly includes a controller, a resistor R, and a capacitor C. The capacitor C is connected in parallel with the inductance of the detection coil 127, and the capacitor C and the inductance of the detection coil 127 can together form a resonant circuit 117. The first end of the resonant circuit 117 is electrically connected to the controller through the resistor R, and the second end of the resonant circuit 117 is grounded. The controller provides a first current signal to the resonant circuit 117 through the resistor R, thereby providing a first current signal to the detection coil, and the detection coil 127 receives the first current signal provided by the controller to generate a first magnetic field, so that the detection coil 127 and the magnetically conductive valve core 123 are electromagnetically coupled, and the voltage value of the first end of the resonant circuit 117 is obtained by the controller to obtain the opening degree between the magnetically conductive valve core 123 and the valve nozzle 125. The resistor R limits the current and divides the voltage of the input first alternating current signal, and the detection coil 127 is equivalent to an inductive device.

[0088] When the distance H between the detection coil 127 and the magnetically conductive valve core 123 changes​Figure 7 ) When the displacement of the magnetic valve core 123 changes, the inductance of the detection coil 127 changes, and when the parallel capacitor C and the inductance of the detection coil 127 form a resonance, the impedance is maximum, and the output signal of the first end of the resonance circuit 117 is maximum. When the inductance changes, the output voltage signal of the resonance circuit 117 changes, and the signal sampling and analysis processing unit 1163 needs to use the calibration data to perform software calculation on the voltage signal after collection and processing. The calculated inductance signal is corrected to realize the voltage signal after collection and processing. Figure 10 ) and the displacement AH of the magnetic valve core 123 Figure 10 ) form a good linear relationship, so that the opening between the magnetic valve core 123 and the valve nozzle 125 can be detected in real time.

[0089] For example, the detection coil 127 can be wound into a circle Figure 11 , square or other shapes by metal wires. In order to avoid increasing the magnetic resistance of the magnetic circuit too much, the thickness of the detection coil 127 can be set smaller. For example, a single layer winding method can be used, and the thickness of the detection coil 127 can be not more than 1mm.

[0090] For example, the second current signal can be a low-frequency signal, and the first current signal can be a high-frequency signal.

[0091] For example, the side of the magnetic column 122 facing the magnetic valve core 123 can have a groove, and the detection coil 127 is located in the groove. The groove can limit the detection coil 127, and also help to reduce the overall volume of the magnetic column 122 and the detection coil 127.

[0092] The first embodiment for obtaining the inductance of the detection coil 127 is described below.

[0093] Referring to Figure 7 , the inductance of the detection coil 127 can be the inductance generated in the detection coil 127 affected by the first magnetic field. The surface of the magnetic valve core 123 opposite to the detection coil 127 is a magnetic surface. The high-frequency first magnetic field generated by the first current signal in the detection coil 127, when the distance H between the magnetic valve core 123 and the detection coil 127 changes under the action of the electromagnetic force of the driving coil 126, will cause the strength of the high-frequency first magnetic field excited by the detection coil 127 to change, thereby causing the inductance of the detection coil 127 to change. For example, the surface of the magnetic valve core 123 facing the magnetic column 122 can be a non-metal surface.

[0094] Specifically, referring to Figure 3 and Figure 7The detection coil 127 generates a high-frequency first magnetic field under the control of the second control module 112. Under the action of the high-frequency first magnetic field, the detection coil 127 generates an equivalent high-frequency inductance, and the inductance value is proportional to the strength of the first magnetic field generated by the detection coil 127. The distance between the magnetically conductive valve core 123 and the detection coil 127 changes under the electromagnetic force of the driving coil 126. Because the distance between the magnetically conductive valve core 123 and the detection coil 127 changes, the first magnetic field changes, that is, the distance change causes the strength of the first magnetic field generated by the detection coil 127 to change, thereby causing the equivalent high-frequency inductance generated by the detection coil 127 to change.

[0095] Referring to Figure 6 , Figure 8 and Figure 9 , the signal conditioning and control module 116 provides a first current signal to the detection coil 127. When the electromagnetic valve 120 is in a closed state, the distance between the detection coil 127 and the magnetically conductive valve core 123 is H1. When the driving coil 126 is provided with a second current signal, an upward attractive force is generated on the magnetically conductive valve core 123, causing the elastic member 124 to deform and the magnetically conductive valve core 123 to move upward by a distance ΔH (i.e., H1-H2). At this time, the distance between the detection coil 127 and the magnetically conductive valve core 123 becomes H2. By providing the detection coil 127 with a first current signal (for example, a 10KHZ square wave or a sine wave), when the distance between the magnetically conductive valve core 123 and the detection coil 127 changes, the strength of the first magnetic field generated by the first current signal changes, causing the inductance value of the detection coil 127 to change.

[0096] The detection coil 127 detects the opening degree between the magnetically conductive valve core 123 and the valve nozzle 125, and the detection speed of the opening degree is fast (less than 1ms). The control board 110 can quickly control the electromagnetic valve 120 according to the opening degree value. The control current of the driving coil 126 is determined according to the detected ΔH (opening degree value), thereby realizing accurate and rapid control of the valve opening degree, and thereby improving the response speed of the MFC to the gas mass flow control.

[0097] The second embodiment of obtaining the inductance value of the detection coil 127 is described below.

[0098] Referring to Figure 7 , the side of the magnetically conductive valve core 123 facing the magnetically conductive column 122 is a metal side, and the first magnetic field acts on the metal side to form an eddy current on the metal side. The eddy current generates an eddy current magnetic field, and the inductance value can be the inductance generated in the detection coil 127 affected by the eddy current magnetic field. For example, the material of the magnetically conductive valve core 123 can include a metal material.

[0099] The first magnetic field excited by the detection coil 127 induces eddy current on the metal surface of the magnetic conductive spool 123, and the magnitude of the eddy current is related to the distance between the metal surface and the detection coil 127. The closer the distance, the stronger the eddy current induced on the metal surface. The eddy current induced on the metal surface generates an alternating eddy current magnetic field, which affects the high-frequency equivalent inductance of the detection coil 127. The principle is similar to the first embodiment, and will not be described again.

[0100] The following describes the isolation member 129 provided by the application.

[0101] Referring to Figure 7 and Figure 12 , the electromagnetic valve 120 can include a non-magnetic conductive isolation member 129, which separates the accommodation cavity into a first accommodation cavity and a second accommodation cavity. The magnetic conductive column 122, the drive coil 126, and the detection coil 127 can be located in the first accommodation cavity, and the magnetic conductive spool 123 and the valve nozzle 125 can be located in the second accommodation cavity. By providing the isolation member 129, the fluid can be prevented from entering the first accommodation cavity from the second accommodation cavity. The detection coil 127 is physically isolated from the magnetic conductive spool 123 by the isolation member 129, and the detection coil 127 is not in fluid contact with the magnetic conductive spool 123, thereby preventing the fluid from adversely affecting the structural members (e.g., the detection coil 127 and the drive coil 126) located in the first accommodation cavity. For example, the fluid can be corrosive, and by providing the isolation member 129, the fluid corrosion can be prevented from causing the detection coil 127 and the drive coil 126 to fail.

[0102] For example, the isolation member 129 is connected to the second magnetic conductive shell 1212, so that the isolation effect between the first accommodation cavity and the second accommodation cavity is good, and fluid leakage in the second accommodation cavity can be prevented. For example, the isolation member 129 is connected to the second magnetic conductive shell 1212 by welding.

[0103] In the embodiment in which the fluid is corrosive, the drive coil 126 and the detection coil 127 are isolated from the fluid by the isolation member 129. The isolation member 129 can be made of a non-magnetic conductive and corrosion-resistant material, thereby avoiding fluid corrosion of the isolation member 129 and improving the isolation effect of the isolation member 129. Similarly, the material of the magnetic conductive spool 123 can include a corrosion-resistant material, and at least part of the surface of the magnetic conductive spool 123 can be a corrosion-resistant surface. For example, the surface of the magnetic conductive spool 123 facing the detection coil 127 is made of a magnetic conductive and corrosion-resistant material (e.g., KM45 stainless steel).

[0104] In the embodiment in which the inductance value of the detection coil 127 is the inductance value generated by the first magnetic field in the detection coil 127, the material of the isolation piece 129 can be a metal material (for example, 316L stainless steel). When the isolation piece 129 is made of a metal material, the isolation piece 129 will also generate an alternating magnetic field under the action of the first magnetic field, which may affect the inductance value of the detection coil 127. The thicker the isolation piece 129 is, the smaller the resistance of the isolation piece 129 is, the stronger the alternating electromagnetic signal induced by the isolation piece 129 is, and the greater the influence on the inductance value is. Therefore, the thickness of the isolation piece 129 needs to be controlled. For example, the thickness of the isolation piece 129 is not more than 2 mm, so that the signal sensitivity detected by the detection coil 127 can be avoided from being affected by the isolation piece 129. The thickness of the isolation piece 129 can be set according to actual needs. The smaller the thickness of the isolation piece 129 is, the greater the electromagnetic force provided by the isolation piece 129 is. Therefore, the thickness of the isolation piece 129 can be set to be smaller. Of course, the thickness of the isolation piece 129 cannot be set too small to prevent the risk of breaking due to the small thickness of the isolation piece 129. Therefore, the minimum thickness of the isolation piece 129 needs to consider the use environment of the isolation piece 129, including air pressure, overall machine size, etc.

[0105] The frequency range of the first current signal can be 10KHZ-100KHZ, so that the first magnetic field is more easily penetrated through the metal isolation piece 129, which is beneficial to reduce the influence of the isolation piece 129 on the first magnetic field.

[0106] In the embodiment in which the inductance value of the detection coil 127 is the inductance value generated by the first magnetic field in the detection coil 127, the material of the isolation piece 129 can be a metal material (for example, 316L stainless steel). When the isolation piece 129 is made of a metal material, the isolation piece 129 will also generate an alternating magnetic field under the action of the first magnetic field, which may affect the inductance value of the detection coil 127. The thicker the isolation piece 129 is, the smaller the resistance of the isolation piece 129 is, the stronger the alternating electromagnetic signal induced by the isolation piece 129 is, and the greater the influence on the inductance value is. Therefore, the thickness of the isolation piece 129 needs to be controlled. For example, the thickness of the isolation piece 129 is not more than 2 mm, so that the signal sensitivity detected by the detection coil 127 can be avoided from being affected by the isolation piece 129. The thickness of the isolation piece 129 can be set according to actual needs. The smaller the thickness of the isolation piece 129 is, the greater the electromagnetic force provided by the isolation piece 129 is. Therefore, the thickness of the isolation piece 129 can be set to be smaller. Of course, the thickness of the isolation piece 129 cannot be set too small to prevent the risk of breaking due to the small thickness of the isolation piece 129. Therefore, the minimum thickness of the isolation piece 129 needs to consider the use environment of the isolation piece 129, including air pressure, overall machine size, etc.

[0107] In the embodiment in which the inductance value of the detection coil 127 is the inductance value generated by the first magnetic field in the detection coil 127, the material of the isolation piece 129 can be a metal material (for example, 316L stainless steel). When the isolation piece 129 is made of a metal material, the isolation piece 129 will also generate an alternating magnetic field under the action of the first magnetic field, which may affect the inductance value of the detection coil 127. The thicker the isolation piece 129 is, the smaller the resistance of the isolation piece 129 is, the stronger the alternating electromagnetic signal induced by the isolation piece 129 is, and the greater the influence on the inductance value is. Therefore, the thickness of the isolation piece 129 needs to be controlled. For example, the thickness of the isolation piece 129 is not more than 2 mm, so that the signal sensitivity detected by the detection coil 127 can be avoided from being affected by the isolation piece 129. The thickness of the isolation piece 129 can be set according to actual needs. The smaller the thickness of the isolation piece 129 is, the greater the electromagnetic force provided by the isolation piece 129 is. Therefore, the thickness of the isolation piece 129 can be set to be smaller. Of course, the thickness of the isolation piece 129 cannot be set too small to prevent the risk of breaking due to the small thickness of the isolation piece 129. Therefore, the minimum thickness of the isolation piece 129 needs to consider the use environment of the isolation piece 129, including air pressure, overall machine size, etc.

[0108] In addition, the embodiments of the present application also provide an electronic device, and the electronic device can include the mass flow controller in the above embodiments. For example, the electronic device can include a semiconductor device.

[0109] It should be noted that the values and value ranges involved in the embodiments of the present application are approximate values, and there can be a certain range of errors due to the influence of the manufacturing process, which can be considered negligible by those skilled in the art.

[0110] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An electromagnetic valve characterized by comprising: The electromagnetic valve is used under the control of a controller assembly, the controller assembly comprises a controller, a resistor and a capacitor, the controller is electrically connected with the resistor, the electromagnetic valve comprises a magnetic conducting shell, a magnetic conducting column, a magnetic conducting spool, a valve nozzle, a driving coil and a detection coil, the magnetic conducting shell has a containing cavity, the magnetic conducting column, the magnetic conducting spool, the valve nozzle, the driving coil and the detection coil are located in the containing cavity, the magnetic conducting column, the magnetic conducting spool and the valve nozzle are sequentially arranged along a first direction, the magnetic conducting column is connected with the magnetic conducting shell, the magnetic conducting spool is movably connected with the valve nozzle along the first direction, and a flow channel is arranged in the valve nozzle; The detection coil is located on the side of the magnetic conducting column facing the magnetic conducting spool, the detection coil is connected with the capacitor in parallel to form a resonance circuit, the first end of the resonance circuit is electrically connected with the controller through the resistor, and the second end of the resonance circuit is grounded; the detection coil is used for receiving a first current signal provided by the controller to generate a first magnetic field, so that the detection coil and the magnetic conducting spool are electromagnetically coupled, so that the controller obtains the voltage value of the first end, and the opening degree between the magnetic conducting spool and the valve nozzle is obtained through the voltage value.

2. The electromagnetic valve according to claim 1, characterized by The side of the magnetic conducting spool facing the magnetic conducting column is a non-metal surface.

3. The electromagnetic valve according to claim 1, characterized by The side of the magnetic conducting spool facing the magnetic conducting column is a metal surface.

4. The electromagnetic valve according to any one of claims 1 to 3, characterized by The electromagnetic valve comprises a non-magnetic conducting isolation piece, the isolation piece separates the containing cavity into a first containing cavity and a second containing cavity, the magnetic conducting column, the driving coil and the detection coil are located in the first containing cavity, and the magnetic conducting spool and the valve nozzle are located in the second containing cavity.

5. The electromagnetic valve according to claim 4, characterized by The material of the isolation piece comprises a metal material; The thickness of the isolation piece is less than or equal to 2mm; and / or, the frequency range of the first current signal is 10KHZ-100KHZ.

6. The electromagnetic valve according to claim 4, characterized by The material of the isolation piece comprises a non-metal material, and the frequency of the first current signal is greater than or equal to 100KHZ.

7. The electromagnetic valve according to claim 4, wherein The material of the isolation piece comprises a corrosion-resistant material; And / or, the material of the magnetic conducting spool comprises a corrosion-resistant material.

8. The electromagnetic valve according to any one of claims 1 to 3, characterized by When the electromagnetic valve is in a closed state, the detection coil and the magnetic conducting spool have a first distance, when the electromagnetic valve is in an open state, the detection coil and the magnetic conducting spool have a second distance, and the opening degree is equal to the difference between the first distance and the second distance.

9. The electromagnetic valve according to any one of claims 1 to 3, characterized by The driving coil is sleeved on the outer periphery of the magnetic conducting column, the controller is electrically connected with the driving coil, when the electromagnetic valve is in an open state, the controller is configured to provide a second current signal to the driving coil to generate a second magnetic field, and the second magnetic field acts on the magnetic conducting spool, so that the magnetic conducting spool is subjected to a magnetic force along the first direction.

10. The electromagnetic valve according to any one of claims 1 to 3, characterized by The electromagnetic valve comprises an elastic piece, one end of the elastic piece is connected with the valve nozzle, the other end of the elastic piece is connected with the magnetic conducting spool, and the elastic piece is used for providing an elastic force to the magnetic conducting spool towards the valve nozzle.

11. The electromagnetic valve according to any one of claims 1 to 3, characterized by The side of the magnetic conducting column facing the magnetic conducting spool has a groove, and the detection coil is located in the groove.

12. An electromagnetic valve assembly characterized by, The electromagnetic valve according to any one of claims 1-11, and a controller assembly electrically connected to the electromagnetic valve.

13. A mass flow controller characterized by, The controller assembly, the fluid passage, the mass flow sensor, and the electromagnetic valve according to any one of claims 1-11, the controller assembly being electrically connected to the mass flow sensor and the electromagnetic valve, the mass flow sensor being configured to measure a mass flow of a fluid in the fluid passage. The controller assembly is configured to look up an opening degree of the electromagnetic valve in a first relationship table in which a correspondence between a mass flow and an opening degree is stored in advance, as an index of the mass flow, and adjust the opening degree of the electromagnetic valve according to the looked-up opening degree.

14. The mass flow controller of claim 13, wherein, The controller assembly is configured to look up a second current signal of the electromagnetic valve in a second relationship table in which a correspondence between an opening degree and a second current signal is stored in advance, as an index of the opening degree of the electromagnetic valve, and adjust the opening degree of the electromagnetic valve according to the looked-up second current signal.

15. The mass flow controller of claim 13, wherein, The mass flow controller according to any one of claims 13-15.

16. An electronic device, comprising: ​

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