Pre-feed gas control method, circuit, and plasma cutting machine

Abstract

This application provides a pre-gas supply control method, circuit, and plasma cutting machine. The control method includes: a main control module sending a gas control signal to a gas valve control module in response to a cutting torch test signal; the gas valve control module supplying test gas to the cutting torch at a first moment in response to the gas control signal; a gas sensing device sending a gas feedback signal to the main control module at a second moment upon sensing the test gas; and the main control module setting a target pre-gas supply time for the plasma cutting machine based on the time interval between the first and second moments. This control method can help form a stable plasma arc, improving the arc ignition success rate and cutting quality of the plasma cutting machine.

Description

Technical Field

[0001] This application relates to the field of cutting machine technology, and in particular to a pre-gas control method, circuit, and plasma cutting machine. Background Technology

[0002] A plasma cutting machine is a device that uses a high-temperature plasma arc to cut and process metal materials. Its cutting efficiency and quality are affected by a variety of factors. Among them, the length of the cutting torch directly determines the time it takes for the gas to reach the nozzle during the cutting process, and the accuracy of the gas arrival time affects the formation process of the plasma arc.

[0003] Currently, the length of the cutting torch and the pre-gas delivery time are usually determined manually or by preset parameters. However, manual measurement or preset parameters rely on the operator's experience and are prone to errors, resulting in inaccurate pre-gas delivery time. This leads to unstable plasma arc formation and seriously affects the success rate of arc ignition and cutting quality of the plasma cutting machine.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] Based on this, embodiments of this application provide a pre-gas supply control method, circuit, and plasma cutting machine, which can help form a stable plasma arc and improve the arc ignition success rate and cutting quality of the plasma cutting machine.

[0006] According to some embodiments, this application provides a pre-gas control method, which is implemented using a control circuit. The control circuit includes a main control module, a gas valve control module and a gas sensing device connected to the main control module, and the gas sensing device is installed at the nozzle of the cutting gun of the plasma cutter.

[0007] The control method includes the following steps:

[0008] The main control module responds to the cutting gun test signal by sending a gas control signal to the gas valve control module;

[0009] The gas valve control module responds to the gas control signal and supplies test gas to the cutting gun at the first moment;

[0010] The gas sensing device sends a gas feedback signal to the main control module at a second moment after sensing the test gas;

[0011] The main control module sets the target pre-gas delivery time of the plasma cutter based on the time interval between the first time and the second time.

[0012] In some embodiments, the cutting gun access signal is used as the cutting gun test signal to trigger the main control module to send the gas control signal to the gas valve control module.

[0013] In some embodiments, the gas sensing device includes at least two test electrodes and an electrode state feedback module connected to the two test electrodes;

[0014] The gas sensing device sends a gas feedback signal to the main control module at a second moment after sensing the test gas, including the following steps:

[0015] In the initial state, the two test electrodes are in contact with each other, forming a short circuit; when the test gas reaches the muzzle, it causes the two test electrodes to separate, interrupting the short circuit between the two test electrodes.

[0016] The electrode state feedback module acquires the output voltage of the two test electrodes and sends the gas feedback signal to the main control module when the output voltage exceeds a preset voltage threshold.

[0017] In some embodiments, the gas sensing device includes a gas pressure detection module;

[0018] The gas sensing device sends a gas feedback signal to the main control module at a second moment after sensing the test gas, including the following steps:

[0019] The gas pressure detection module measures the gas pressure at the muzzle and sends a gas feedback signal to the main control module when the gas pressure exceeds a preset gas pressure threshold.

[0020] In some embodiments, setting the target pre-gas delivery time of the plasma cutter based on the time interval between the first time moment and the second time moment includes the following steps:

[0021] The recognition length of the cutting gun is determined based on the time interval.

[0022] Obtain the correspondence between multiple lengths of the cutting gun and multiple standard pre-gas delivery times;

[0023] Based on the correspondence, the standard pre-gas delivery time corresponding to the identification length is selected as the target pre-gas delivery time.

[0024] In some embodiments, after setting the target pre-gas delivery time, the control method further includes the following steps:

[0025] The target pre-gas delivery time is stored.

[0026] In some embodiments, the control method further includes the following steps:

[0027] The main control module responds to the power-on signal of the cutting machine and determines whether it has received the cutting gun access signal.

[0028] When it is determined that the cutting gun access signal has not been received, the main control module generates an alarm message.

[0029] In some embodiments, in response to each cutting gun access signal, the main control module sets the target pre-gas delivery time of the plasma cutter.

[0030] According to some embodiments, this application provides a pre-gas delivery control circuit for implementing the control method as described in any one of claims 1 to 8, comprising: a main control module, and a gas valve control module and a gas sensing device connected to the main control module;

[0031] The main control module is configured to send a gas control signal to the gas valve control module in response to the cutting gun test signal.

[0032] The gas valve control module is configured to supply test gas to the cutting gun at a first moment in response to the gas control signal.

[0033] The gas sensing device is installed at the muzzle of the cutting gun and is configured to send a gas feedback signal to the main control module at a second moment when the test gas is sensed.

[0034] The main control module is further configured to set the target pre-gas delivery time of the plasma cutter based on the time interval between the first time and the second time.

[0035] In some embodiments, the gas sensing device includes: at least two test electrodes, and an electrode state feedback module connected to the two test electrodes;

[0036] When the two test electrodes are in the initial state, they are in contact with each other and form a short circuit; when the test gas reaches the muzzle, it causes the two test electrodes to separate, interrupting the short circuit between the two test electrodes.

[0037] The electrode state feedback module is connected to the two test electrodes and is configured to: acquire the output voltage of the two test electrodes and feed the output voltage back to the main control module.

[0038] According to some embodiments, this application also provides a plasma cutting machine, the plasma cutting machine including: a cutting torch, and the control circuit provided in the foregoing embodiments.

[0039] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application.

[0040] The embodiments of this application may have, or at least have, the following advantages:

[0041] In this embodiment, the main control module supplies test gas to the cutting torch at a first moment, and the gas sensing device detects the test gas reaching the nozzle at a second moment. The time interval between the first and second moments represents the time required for the test gas to travel from the gas valve to the cutting torch nozzle. A longer time interval indicates a longer cutting torch, thus requiring a longer pre-gas delivery time to ensure the necessary gas environment for the cutting area. Setting the target pre-gas delivery time for the plasma cutter based on the time interval between the first and second moments eliminates the need for manual intervention or additional measurement steps, thus improving the automation level of the control method.

[0042] Based on this, the main control module can precisely set the target pre-gas delivery time of the plasma cutter according to the time interval between the first and second moments, thereby effectively reducing the situation of excessive or insufficient pre-gas delivery and avoiding unstable plasma arc formation due to inaccurate pre-gas delivery, which would affect cutting efficiency. Especially for longer cutting torches, the time interval between the first and second moments will be longer, and this control method can automatically adjust the pre-gas delivery time, thereby significantly improving the arc ignition success rate. Therefore, the embodiments of this application can help form a stable plasma arc, which is beneficial to improving the arc ignition success rate and cutting quality of the plasma cutter.

[0043] Other advantages, objectives, and features of this application will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from practice of this application. The objectives and other advantages of this application can be realized and obtained through the following description. Attached Figure Description

[0044] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings.

[0045] Figure 1 This is a schematic diagram of the control circuit provided in some embodiments of this application;

[0046] Figure 2 A flowchart illustrating the control method provided in some embodiments of this application;

[0047] Figure 3A schematic flowchart illustrating the transmission of gas feedback signals in a control method provided in some embodiments of this application;

[0048] Figure 4 A flowchart illustrating the setting of a target pre-gas delivery time in a control method provided in some embodiments of this application;

[0049] Figure 5 This is a schematic diagram of the process for generating alarm information in the control method provided in some embodiments of this application.

[0050] Explanation of reference numerals in the attached figures:

[0051] 100 Main Control Module

[0052] 200 air valve control module

[0053] 300 Gas Sensing Device Detailed Implementation

[0054] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0056] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0057] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” or “having,” etc., specify the presence of the stated feature, whole, step, operation, component, part, or combination thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof.

[0058] Currently, the length of the cutting torch and the pre-gas delivery time are usually determined manually or by preset parameters. However, manual measurement or preset parameters rely on the operator's experience and are prone to errors, resulting in inaccurate pre-gas delivery time. This leads to unstable plasma arc formation and seriously affects the success rate of arc ignition and cutting quality of the plasma cutting machine.

[0059] Therefore, this application aims to provide a solution that can address the aforementioned technical problems, helping to form a stable plasma arc and improving the arc ignition success rate and cutting quality of plasma cutting machines. Details will be elaborated in subsequent embodiments.

[0060] On the one hand, this application provides a pre-gas supply control method. This control method can utilize, for example... Figure 1 The control circuit shown includes a main control module 100, a gas valve control module 200 and a gas sensing device 300 connected to the main control module 100; wherein the gas sensing device 300 can be installed at the nozzle of the cutting gun of the plasma cutter.

[0061] Please combine Figure 1 See Figure 2 The control method may specifically include the following steps S100 to S400:

[0062] S100: In response to the cutting gun test signal, the main control module 100 sends a gas control signal to the gas valve control module 200.

[0063] S200: The gas valve control module 200 responds to the gas control signal and supplies test gas to the cutting gun at the first moment.

[0064] S300: The gas sensing device 300 sends a gas feedback signal to the main control module 100 at the second moment after sensing the test gas.

[0065] S400: The main control module 100 sets the target pre-gas delivery time of the plasma cutter based on the time interval between the first moment and the second moment.

[0066] It should be noted that the "pre-gas supply" mentioned in this application, also known as "system pre-gas supply," refers to the process of introducing gas into the cutting area before the plasma cutter begins cutting, in order to help form a plasma arc and improve cutting quality. This gas may include compressed air or an inert gas (such as argon, nitrogen, etc.), the purpose of which is to provide the necessary gaseous environment for the cutting area before cutting begins.

[0067] In the control circuit provided in this application, the main control module 100 supplies test gas to the cutting torch at a first moment according to the gas valve control module 200, and the gas sensing device 300 senses a second moment when the test gas reaches the nozzle. The time interval between the first and second moments represents the time required for the test gas to travel from the gas valve to the nozzle of the cutting torch. The longer the time interval, the longer the cutting torch, and therefore a longer pre-gas delivery time is required to ensure the necessary gas environment is provided for the cutting area. Setting the target pre-gas delivery time for the plasma cutter based on the time interval between the first and second moments requires no manual intervention or additional measurement steps, which improves the automation level of the control method.

[0068] Based on this, the main control module 100 can precisely set the target pre-gas delivery time of the plasma cutter according to the time interval between the first and second moments, thereby effectively reducing the situation of excessive or insufficient pre-gas delivery and avoiding unstable plasma arc formation due to inaccurate pre-gas delivery, which would affect cutting efficiency. Especially for longer cutting torches, the time interval between the first and second moments will be longer, and this control method can automatically adjust the pre-gas delivery time, thereby significantly improving the arc ignition success rate. Therefore, the control circuit provided in this application can help form a stable plasma arc, which is beneficial to improving the arc ignition success rate and cutting quality of the plasma cutter, especially suitable for longer cutting torches, and can significantly improve the arc ignition success rate.

[0069] In some embodiments, for step S100, the cutting gun access signal is used as the cutting gun test signal to trigger the main control module 100 to send a gas control signal to the gas valve control module 200.

[0070] It should be noted that the "cutting gun access signal" mentioned in the above embodiments is a signal used to indicate that the cutting gun has been correctly connected and is ready. When the cutting gun access signal is generated, it indicates that the cutting gun is able to receive control commands and has the necessary conditions to start high-voltage discharge and ignite the plasma arc.

[0071] For step S200, as an example, the gas that is pre-introduced into the cutting area in the actual working scenario can be used as the test gas, such as compressed air or inert gas (argon, nitrogen, etc.). This can more realistically simulate the gas flow and improve the accuracy of the cutting gun length recognition. Furthermore, using the gas that will be used in the actual working scenario eliminates the need to prepare a specific test gas and avoids increasing gas management costs.

[0072] In step S300, the gas sensing device 300 sends a gas feedback signal to the main control module 100 at the second moment after sensing the test gas, indicating that the test gas has reached the muzzle at this moment. How to specifically detect whether the test gas has reached the muzzle will be described below in conjunction with specific embodiments.

[0073] In some embodiments, the gas sensing device 300 of the control circuit includes at least two test electrodes and an electrode state feedback module connected to the two test electrodes.

[0074] Based on this, please refer to Figure 3 In step S300, the gas sensing device 300 sends a gas feedback signal to the main control module 100 at the second moment when it senses the test gas. Specifically, this may include the following steps S310 to S320.

[0075] In step S310, when the two test electrodes are in the initial state, they are in contact with each other and form a short circuit; when the test gas reaches the nozzle, it causes the two test electrodes to separate, interrupting the short circuit state of the two test electrodes.

[0076] In step S320, the electrode state feedback module acquires the output voltage of the two test electrodes and sends a gas feedback signal to the main control module 100 when the output voltage exceeds the preset voltage threshold.

[0077] In the above embodiment, the arrival of the test gas is sensed by the change in the short-circuit state of the two test electrodes. When no test gas arrives, the two test electrodes are in contact, forming a short circuit. In the short-circuit state, the voltage between the two test electrodes (i.e., the output voltage obtained by the electrode state feedback module) is 0. When the test gas reaches the muzzle, the two test electrodes are blown apart, thus interrupting the original short-circuit state. Once the two test electrodes are no longer short-circuited, a voltage is generated between them. Therefore, when the output voltage exceeds a preset voltage threshold (e.g., the output voltage is greater than 0), it means that the two test electrodes are no longer short-circuited, and it can be determined that the test gas has reached the muzzle of the cutting gun.

[0078] The design of the two test electrodes and electrode status feedback module is simple, easy to manufacture and install, and has high reliability and stability. Using two test electrodes and an electrode status feedback module to sense the test gas provides more reliable and accurate gas sensing feedback, further improving the arc ignition success rate and cutting quality of the plasma cutter.

[0079] Ideally, the voltage between the two test electrodes is zero under short-circuit conditions. However, in practical applications, due to factors such as resistance and limitations in the accuracy of measuring instruments, a very, very small voltage value exists between the two test electrodes, close to zero but not strictly zero. Therefore, the above embodiment sets a sufficiently low preset voltage threshold to distinguish between the short-circuit state and the state after gas arrival.

[0080] In other embodiments, the gas sensing device 300 of the control circuit includes a gas pressure detection module.

[0081] Based on this, in step S300, the gas sensing device 300 sends a gas feedback signal to the main control module 100 at the second moment after sensing the test gas, which can be specifically manifested as follows:

[0082] The gas pressure detection module measures the gas pressure at the muzzle and sends a gas feedback signal to the main control module 100 when the gas pressure exceeds the preset gas pressure threshold.

[0083] In the above embodiments, when the test gas reaches the muzzle, the gas pressure at the muzzle changes due to gas flow. By setting a preset gas pressure threshold, which can be determined based on the normal pressure range of the muzzle when no test gas passes through, it can be determined whether the test gas has reached the muzzle.

[0084] The above embodiments directly measure the gas pressure at the muzzle, providing direct information about the presence and flow of gas. The gas pressure detection module (e.g., a gas pressure sensor) can respond quickly, thus detecting changes in gas pressure at the muzzle in a timely manner.

[0085] For step S400, please refer to Figure 4 In some embodiments, the target pre-gas delivery time of the plasma cutter can be set using the following steps S410 to S430.

[0086] In step S410, the main control module 100 determines the identification length of the cutting gun based on the time interval between the first and second moments. This process requires no manual intervention or additional measurement steps, which helps to improve the automation level of the control method.

[0087] In step S420, the correspondence between multiple lengths of the cutting gun and multiple standard pre-gas times is obtained.

[0088] As an example, before the equipment leaves the factory, multiple cutting torches of different lengths can be installed on the plasma cutting machine, and multiple different pre-gas delivery times can be set for each torch length. Then, pre-gas delivery tests are performed on the cutting torches at these different times, and the cutting effect of the current length of cutting torch under different pre-gas delivery times is compared. The pre-gas delivery time that achieves the best cutting effect is selected as the standard pre-gas delivery time for the current length. A correspondence is established between multiple lengths and their corresponding standard pre-gas delivery times. For example, this correspondence can be recorded and saved in the plasma cutting machine's database or memory storage for later retrieval; it can also be written into technical documentation for reference in subsequent production, quality control, and customer use.

[0089] In step S430, based on the correspondence, the standard pre-gas delivery time corresponding to the identification length is selected as the target pre-gas delivery time.

[0090] In the above embodiments, by pre-establishing the correspondence between the length of the cutting gun and the standard pre-gas delivery time (e.g., based on pre-shipment test data), precise selection of the target pre-gas delivery time can be achieved, reducing manual intervention required after deployment and avoiding errors that may be caused by relying solely on experience or fixed value settings. Furthermore, using the above embodiments, users do not need to delve into specific parameter adjustments; they can simply operate the cutting gun as required to complete precise settings, making the equipment easier to operate and providing a more user-friendly experience.

[0091] For example, suppose the following correspondence is obtained through multiple sets of pre-air supply tests: the standard pre-air supply time for a cutting gun with a length of 5m is 350ms, the standard pre-air supply time for a cutting gun with a length of 20m is 1s, and the standard pre-air supply time for a cutting gun with a length of 10m is 700ms.

[0092] When the main control module 100 calculates that the time interval between the first moment and the second moment is 1s, it finds out that the cutting gun length corresponding to the standard pre-gas delivery time of 1s is 20m based on the above correspondence. Therefore, it is known that the identification length of the cutting gun is 20m. Then, the main control module 100 sets the target pre-gas delivery time of the plasma cutter to 1s according to the identification length of the cutting gun of 20m.

[0093] In some embodiments, after setting the target pre-gas delivery time, the target pre-gas delivery time can also be stored. For example, the current identification length and the target pre-gas delivery time can be saved to the device's database or internal storage by the main control module 100, which helps with subsequent troubleshooting or performance analysis, such as tracking the operating status of the plasma cutter at different points in time, helping users or engineers analyze historical data, find problems, and optimize operations, etc.

[0094] The following uses the cutting gun input signal as the cutting gun test signal as an example to illustrate some specific embodiments.

[0095] In some embodiments, please refer to Figure 5 The control method may further include the following steps S110 to S120.

[0096] In step S110, the main control module 100 responds to the power-on signal of the cutting machine and determines whether it has received a cutting gun access signal.

[0097] In step S120, when it is determined that no cutting gun access signal has been received, the main control module 100 generates an alarm message.

[0098] The above embodiment generates an alarm message when no cutting gun access signal is received, which can remind the user to check the equipment connection status in time and avoid starting the plasma cutter in an incorrect state, which may cause equipment damage or other safety problems. This helps to improve the reliability and safety of the plasma cutter during use.

[0099] In some embodiments, in response to each cutting gun access signal, the main control module 100 sets the target pre-gas delivery time of the plasma cutter.

[0100] It is understandable that during the use of a plasma cutter, whenever the cutting torch connection signal is interrupted and a new cutting torch connection signal is acquired, it indicates that the cutting torch has been replaced or reconnected.

[0101] After the cutting gun is replaced or reconnected, the above embodiment automatically repeats steps S100 to S400 to reset the target pre-gas delivery time without requiring manual adjustment by the user. This avoids omissions that may be caused by manual operation and further reduces equipment preparation time, which is beneficial to improving cutting efficiency.

[0102] Based on the same inventive concept, this application also provides a pre-air supply control circuit for implementing the control method provided in the foregoing embodiments. This control circuit can also achieve all the technical effects achievable by the foregoing control method, and will not be described in detail hereafter.

[0103] Please continue reading. Figure 1 The control circuit may specifically include: a main control module 100, and a gas valve control module 200 and a gas sensing device 300 connected to the main control module 100.

[0104] The main control module 100 is configured to send a gas control signal to the gas valve control module 200 in response to the cutting gun test signal; the gas valve control module 200 is configured to supply test gas to the cutting gun at a first moment in response to the gas control signal; and the gas sensing device 300 is installed at the muzzle of the cutting gun and is configured to send a gas feedback signal to the main control module 100 at a second moment when the test gas is sensed.

[0105] In the control circuit provided in this application, the main control module 100 can set the target pre-gas delivery time of the plasma cutter according to the time interval between the first moment and the second moment.

[0106] In some embodiments of the control circuit, the gas sensing device 300 may specifically include at least two test electrodes and an electrode state feedback module connected to the two test electrodes.

[0107] When the two test electrodes are initially in contact, they form a short circuit. When the test gas reaches the muzzle, the two test electrodes separate, interrupting the short circuit. The electrode status feedback module is connected to the two test electrodes to acquire their output voltages and feed them back to the main control module.

[0108] It should be noted that the pre-gas control circuits in the embodiments of this application can all be used to implement the corresponding control methods. Therefore, the technical features between the method embodiments and the circuit embodiments can be substituted and supplemented for each other without conflict, so that those skilled in the art can understand the technical content of this application.

[0109] Those skilled in the art will understand that Figure 1 The structure shown is merely a schematic diagram of some modules related to the solution of this application and does not constitute a limitation on the modules applied thereto. The specific control circuit may include more existing functional modules than shown in the figure, or combine some existing functional modules, or have different module arrangements.

[0110] According to some embodiments, this application further provides a plasma cutting machine, which includes a cutting torch and the control circuit provided in the foregoing embodiments. Since the control circuit provided in this application is used to implement the control method provided in the foregoing embodiments, the plasma cutting machine can also achieve all the technical effects that the foregoing control method can achieve, and will not be described in detail here.

[0111] In the description of this specification, references to terms such as "some embodiments," "as an example," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0112] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above 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.

[0113] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A pre-gas supply control method, characterized in that, The control method is implemented using a control circuit, which includes a main control module, a gas valve control module and a gas sensing device connected to the main control module, and the gas sensing device is installed at the nozzle of the cutting gun of the plasma cutting machine. The control method includes the following steps: The main control module responds to the cutting gun test signal by sending a gas control signal to the gas valve control module; The gas valve control module responds to the gas control signal and supplies test gas to the cutting gun at the first moment; The gas sensing device sends a gas feedback signal to the main control module at a second moment after sensing the test gas; The main control module sets the target pre-gas delivery time of the plasma cutter based on the time interval between the first time and the second time. The gas sensing device includes at least two test electrodes and an electrode state feedback module connected to the two test electrodes; the gas sensing device sends a gas feedback signal to the main control module at a second moment when it senses the test gas, including the following steps: when in the initial state, the two test electrodes are in contact with each other to form a short circuit; when the test gas reaches the muzzle, it causes the two test electrodes to separate, interrupting the short circuit state of the two test electrodes; The electrode state feedback module acquires the output voltage of the two test electrodes, and sends the gas feedback signal to the main control module when the output voltage exceeds a preset voltage threshold. Alternatively, the gas sensing device includes a gas pressure detection module; the gas sensing device sends a gas feedback signal to the main control module at a second moment when it senses the test gas, including the following steps: the gas pressure detection module measures the gas pressure at the muzzle, and sends the gas feedback signal to the main control module when the gas pressure exceeds a preset gas pressure threshold.

2. The pre-gas supply control method according to claim 1, characterized in that, The cutting gun access signal is used as the cutting gun test signal to trigger the main control module to send the gas control signal to the gas valve control module.

3. The pre-gas supply control method according to claim 1, characterized in that, The step of setting the target pre-gas delivery time of the plasma cutter based on the time interval between the first time moment and the second time moment includes the following steps: The recognition length of the cutting gun is determined based on the time interval. Obtain the correspondence between multiple lengths of the cutting gun and multiple standard pre-gas delivery times; Based on the correspondence, the standard pre-gas delivery time corresponding to the identification length is selected as the target pre-gas delivery time.

4. The pre-gas supply control method according to claim 1, characterized in that, After setting the target pre-gas delivery time, the control method further includes the following steps: The target pre-gas delivery time is stored.

5. The pre-gas supply control method according to claim 2, characterized in that, The control method further includes the following steps: The main control module responds to the power-on signal of the cutting machine and determines whether it has received the cutting gun access signal. When it is determined that the cutting gun access signal has not been received, the main control module generates an alarm message.

6. The pre-gas supply control method according to claim 2 or 5, characterized in that, In response to each incoming signal from the cutting gun, the main control module sets the target pre-gas delivery time for the plasma cutter.

7. A pre-gas supply control circuit, characterized in that, The control method for implementing any one of claims 1 to 6 includes: a main control module, and a gas valve control module and a gas sensing device connected to the main control module; The main control module is configured to send a gas control signal to the gas valve control module in response to the cutting gun test signal. The gas valve control module is configured to supply test gas to the cutting gun at a first moment in response to the gas control signal. The gas sensing device is installed at the muzzle of the cutting gun and is configured to send a gas feedback signal to the main control module at a second moment when the test gas is sensed. The main control module is further configured to: set the target pre-gas delivery time of the plasma cutter based on the time interval between the first time and the second time. The gas sensing device includes at least two test electrodes and an electrode status feedback module connected to the two test electrodes. When the two test electrodes are in their initial state, they are in contact with each other, forming a short circuit. When the test gas reaches the muzzle, it causes the two test electrodes to separate, interrupting the short circuit. The electrode status feedback module is connected to the two test electrodes and configured to: acquire the output voltage of the two test electrodes and feed the output voltage back to the main control module. Alternatively, the gas sensing device includes a gas pressure detection module; the gas sensing device sends a gas feedback signal to the main control module at a second moment when it senses the test gas, including the following steps: the gas pressure detection module measures the gas pressure at the muzzle, and sends the gas feedback signal to the main control module when the gas pressure exceeds a preset gas pressure threshold.

8. A plasma cutting machine, characterized in that, The plasma cutting machine includes: a cutting torch, and a control circuit as described in claim 7.

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