Method for diagnosing failure of electromagnetic directional valve

Abstract

The application discloses a fault diagnosis method of an electromagnetic reversing valve, and relates to the technical field of electromagnetic reversing valves. The method comprises the following steps: acquiring an input current change curve and an output voltage change curve of a valve control unit, acquiring a valve core signal output state of the electromagnetic reversing valve, and performing fault diagnosis on the electromagnetic reversing valve according to the input current change curve, the output voltage change curve and the valve core signal output state. According to the input current change curve and the output voltage change curve of the valve control unit and the valve core signal output state of the electromagnetic reversing valve, the fault diagnosis on the electromagnetic reversing valve can be automatically realized, so that the electromagnetic reversing valve fault can be found in time, and the safety hidden danger can be avoided.

Description

Technical Field

[0001] This application relates to the field of electromagnetic directional valve technology, and in particular to a fault diagnosis method for electromagnetic directional valves. Background Technology

[0002] As a core control component of hydraulic and pneumatic systems, the electromagnetic directional valve has a wide range of applications in industrial automation. It mainly consists of a valve body, spring, valve core, and coil. Electromagnetic force drives the valve core to switch hydraulic oil passages, guiding the hydraulic oil to transmit power and achieve different mechanical action requirements.

[0003] In actual production applications, manual troubleshooting and replacement are generally only carried out when the solenoid directional valve is damaged and affects the operation of the actuators. This method relies on manual fault detection, and since a machine often uses multiple solenoid directional valves, it is easy for faults in the solenoid directional valves to be not detected in time, posing a safety hazard. Summary of the Invention

[0004] The purpose of this application is to provide a fault diagnosis method for electromagnetic directional valves, so as to solve the problem that manual fault detection can easily lead to untimely fault detection of electromagnetic directional valves, which poses a safety hazard.

[0005] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, embodiments of this application provide a fault diagnosis method for an electromagnetic directional valve, comprising: acquiring the input current change curve and the output voltage change curve of a valve control unit; acquiring the valve core signal output state of the electromagnetic directional valve; and performing fault diagnosis on the electromagnetic directional valve based on the input current change curve, the output voltage change curve, and the valve core signal output state.

[0007] The above-described technical solutions adopted in the embodiments of this application can achieve the following beneficial effects:

[0008] In this embodiment of the application, when diagnosing faults in an electromagnetic directional valve, the input current variation curve and output voltage variation curve of the valve control unit, as well as the valve core signal output state of the electromagnetic directional valve, are acquired. Based on these curves, fault diagnosis is performed on the electromagnetic directional valve. This embodiment of the application can automatically diagnose faults in the electromagnetic directional valve based on the input current variation curve and output voltage variation curve of the valve control unit, as well as the valve core signal output state of the electromagnetic directional valve, thereby promptly detecting electromagnetic directional valve faults and avoiding potential safety hazards. Attached Figure Description

[0009] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0010] Figure 1 A flowchart illustrating a fault diagnosis method for an electromagnetic directional valve provided in one embodiment of this application;

[0011] Figure 2 This is a schematic diagram of a three-position four-way solenoid directional valve.

[0012] Figure 3 This is a schematic diagram of the principle of a three-position four-way solenoid directional valve.

[0013] Figure 4 A schematic diagram of a fault diagnosis system for an electromagnetic directional valve provided in one embodiment of this application;

[0014] Figure 5 A schematic diagram of the standard current variation curve and standard voltage variation curve of the electromagnetic directional valve during normal operation, provided for one embodiment of this application;

[0015] Figure 6 A schematic diagram of the core control unit provided in one embodiment of this application;

[0016] Figure 7 A schematic diagram of the current and voltage change curves when the valve core of an electromagnetic directional valve experiences a stuck failure, provided as an embodiment of this application.

[0017] Figure 8 A schematic diagram of the current and voltage change curves of an electromagnetic directional valve when a coil burns out (short circuit) fault occurs, provided for one embodiment of this application;

[0018] Figure 9 A schematic diagram of the current and voltage change curves of an electromagnetic directional valve when a coil burns out (open circuit) fault occurs, provided for one embodiment of this application;

[0019] Figure 10 A schematic diagram of the current and voltage change curves when a spring breakage fault occurs in an electromagnetic directional valve according to an embodiment of this application;

[0020] Figure 11 A schematic diagram of the current and voltage change curves of an electromagnetic directional valve when a valve core hysteresis fault occurs, provided for one embodiment of this application.

[0021] Figure 12 A schematic diagram of the overall process for diagnosing a fault in an electromagnetic directional valve, provided for another embodiment of this application;

[0022] Figure 13 A schematic diagram of the fault diagnosis process of an electromagnetic directional valve during normal operation, provided for one embodiment of this application;

[0023] Figure 14 A schematic diagram of the fault diagnosis process when the valve core of an electromagnetic reversing valve is stuck, provided as an embodiment of this application;

[0024] Figure 15 A schematic diagram of the fault diagnosis process when the electromagnetic reversing valve experiences a coil burnout (short circuit) fault, as provided in one embodiment of this application;

[0025] Figure 16 A schematic diagram of the fault diagnosis process when the electromagnetic reversing valve experiences a coil burnout (open circuit) fault, as provided in one embodiment of this application;

[0026] Figure 17 A schematic diagram of the fault diagnosis process when the spring of the electromagnetic reversing valve breaks down, provided as an embodiment of this application;

[0027] Figure 18 This is a schematic diagram of the fault diagnosis process when the valve core of an electromagnetic directional valve experiences a hysteresis fault, as provided in one embodiment of this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein. Furthermore, "and / or" in this application indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship. It should be noted that all data involved in this application was obtained with the user's authorization.

[0030] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0031] Figure 1 This is a flowchart illustrating a fault diagnosis method for an electromagnetic directional valve, provided as an embodiment of this application. Figure 1 As shown, the fault diagnosis method for the electromagnetic directional valve in this application embodiment may specifically include the following steps:

[0032] S101, obtain the input current change curve and output voltage change curve of the valve control unit.

[0033] S102, obtain the valve core signal output status of the solenoid directional valve.

[0034] S103 performs fault diagnosis on the solenoid directional valve based on the input current change curve, output voltage change curve, and valve core signal output status.

[0035] In this application embodiment, the execution subject of the fault diagnosis method of the electromagnetic reversing valve in this application embodiment can be the core control unit of the electromagnetic reversing valve fault diagnosis system provided in this application embodiment. The electromagnetic reversing valve fault diagnosis system can be applied to mechanical equipment such as sanding machines and injection molding machines.

[0036] The electromagnetic directional valve in this embodiment of the application may specifically be: Figure 2 The three-position four-way solenoid directional valve shown is not limited in this application's embodiments. Figure 2 As shown, the three-position four-way solenoid directional valve includes: valve body 1, spring 2, spring seat 3, valve core 4, coil 5, armature 6, spacer 7, housing 8, and plug assembly 9.

[0037] like Figure 3 As shown, when the coil in the electromagnetic reversing valve is energized, it generates a magnetic force that attracts the valve core to overcome the spring pressure and move. The movement of the valve core is used to switch different flow channels, thereby controlling the direction of oil flow.

[0038] Figure 4 This is a schematic diagram of the fault diagnosis system for the electromagnetic directional valve provided in an embodiment of this application. Figure 4 As shown, the fault diagnosis system for the electromagnetic directional valve in this embodiment of the application may specifically include: a human-machine interface 41 and a controller 42 connected to the human-machine interface. The controller 42 may include a valve control unit 421 and a power supply 422, a core control unit 423, a current detection unit 424, and a voltage detection unit 425 respectively connected to the valve control unit 421.

[0039] The core control unit 423 may include: a generation subunit 4231 connected to the current detection unit 424 and the voltage detection unit 425 respectively, and a fault diagnosis subunit 4232 connected to the generation subunit 4231 and the valve control unit 421 respectively.

[0040] The human-machine interface 41 can input data via buttons and touch screen, and output data via screen display, enabling the fault diagnosis system to display data, perform actions, set parameters, and interact with personnel.

[0041] The controller 42 can collect and control the position, temperature and status of various components in mechanical equipment such as sanders and injection molding machines through built-in analog and digital input and output ports and core control unit 423, so as to realize the action of various component mechanisms in mechanical equipment such as sanders and injection molding machines as required and realize corresponding functions.

[0042] Power supply 422 is used to supply power to valve control unit 421. Power supply 422 is generally an externally input DC power supply with a voltage value of 24V±10%.

[0043] The core control unit 423 is used to output valve control signals to the valve control unit 421 according to the normal operating sequence of mechanical equipment such as sanders and injection molding machines. The core control unit 423 may be an embedded processor, which integrates functional modules related to the embodiments of this application.

[0044] The valve control unit 421, based on the valve control signal output by the core control unit 423, uses power switching technology to output a valve core signal to control the coil of the solenoid directional valve 43 to be energized, de-energized, or maintain its current state, thereby controlling the operation of the solenoid directional valve 43. The valve control unit 421 may have built-in overcurrent and overtemperature protection; when the control load is short-circuited, the output will be shut off. There can be one or more valve control units 421 and solenoid directional valves 43, with a one-to-one correspondence between multiple valve control units 421 and multiple solenoid directional valves 43.

[0045] The current detection unit 424 is used to collect the input current I of the valve control unit 421 in real time, that is, to collect the coil current I of the solenoid directional valve 43, and input it to the core control unit 423.

[0046] The voltage detection unit 425 is used to acquire the output voltage U of the valve control unit 421 in real time, that is, to acquire the coil voltage U of the solenoid directional valve 43, and input it to the core control unit 423.

[0047] The generation subunit 4231 is used to generate an input current change curve I(t) based on the input current I of the valve control unit 421 collected by the current detection unit 424, generate an output voltage change curve U(t) based on the output voltage U of the valve control unit 421 collected by the voltage detection unit 425, and generate a valve core signal output state based on the feedback of the action execution component after the valve core signal is output.

[0048] The fault diagnosis subunit 4232 is used to diagnose the faults of the electromagnetic directional valve 43 based on the input current change curve I(t), the output voltage change curve U(t), and the valve core signal output status.

[0049] Specifically, step S103, "diagnosing faults in the solenoid directional valve based on the input current change curve, the output voltage change curve, and the valve core signal output status," may include the following steps:

[0050] Obtain the standard current variation curve, standard voltage variation curve, and standard valve core signal output status when the solenoid directional valve is operating normally. If the input current variation curve, output voltage variation curve, and valve core signal output status are consistent with the standard current variation curve, standard voltage variation curve, and standard valve core signal output status, respectively, then the solenoid directional valve is determined to be normal. If the input current variation curve, output voltage variation curve, and valve core signal output status are inconsistent with at least one of the standard current variation curve, standard voltage variation curve, and standard valve core signal output status, then the solenoid directional valve is determined to be faulty.

[0051] The standard current variation curve I0(t), standard voltage variation curve U0(t), and standard valve core signal output state of the solenoid directional valve during normal operation can be obtained through valve parameter self-learning when the solenoid directional valve is used for the first time, and stored in the core control unit. Valve parameter self-learning: When the solenoid directional valve is used for the first time, under depressurization conditions, the core control unit outputs valve control signals sequentially. The valve control unit outputs control signals to operate the solenoid directional valve, samples the current, voltage, and feedback from the actuators after the valve core signal output of each solenoid directional valve, and saves the collected data into the core control unit as preset values ​​after self-learning. When the solenoid directional valve is not used for the first time, the fault diagnosis process of this application embodiment is executed.

[0052] Figure 5 This is a schematic diagram showing the standard current and voltage variation curves during normal operation of an electromagnetic directional valve. Figure 5 As shown, the core control unit outputs a valve control signal. When the valve control unit outputs, the coil of the solenoid directional valve is energized, and the coil voltage instantly increases to its rated voltage. According to the working principle of the solenoid directional valve, due to the inductance effect of the coil, the coil circuit current increases. At this time, the coil magnetic force is less than the spring pressure, the valve core remains stationary, and the coil inductance remains unchanged. If the current is further increased, the coil magnetic force becomes greater than the spring pressure, the valve core moves, the coil inductance increases, and the current decreases or balances out. After the valve core reaches its position, the coil inductance no longer changes, and the circuit current continues to increase to the coil's rated current. When the valve control unit closes its output, the coil of the solenoid directional valve is de-energized, the coil voltage instantly drops to zero, the valve core resets, and the coil circuit current returns to zero after a plateau period.

[0053] In addition, when the electromagnetic directional valve is used for the first time, the alarm threshold range can be set through the human-machine interface, such as the current and voltage magnitude, response time, and difference range threshold, and stored in the core control unit 423. The system default difference range threshold is 10%. When the core control unit 423 determines that the difference range between the collected input current, output voltage, and valve parameters obtained through self-learning exceeds the difference range threshold, an alarm signal is output. For example, if the collected input current is 0.9 amps (A) and the preset value of the input current obtained through self-learning is 1A, if the set current difference range threshold is 20%, no alarm signal is output; if the set current difference range threshold is 5%, an alarm signal is output.

[0054] Correspondingly, such as Figure 6 As shown, Figure 4 The core control unit 423 may also include a storage subunit 4233 connected to the fault diagnosis subunit 4232.

[0055] Storage subunit 4233 is used to store the standard current change curve, standard voltage change curve and standard valve core signal output status when the electromagnetic directional valve is working normally.

[0056] The fault diagnosis subunit 4232 is specifically used to: determine that the electromagnetic directional valve 43 is normal if the input current change curve, output voltage change curve, and valve core signal output state are consistent with the standard current change curve, standard voltage change curve, and standard valve core signal output state, respectively; and determine that the electromagnetic directional valve 43 is faulty if at least one of the input current change curve, output voltage change curve, and valve core signal output state is inconsistent with the standard current change curve, standard voltage change curve, and standard valve core signal output state.

[0057] Furthermore, after the above step "determining that the solenoid directional valve is normal", the fault diagnosis method for the solenoid directional valve in this application embodiment may further include the following steps: continuously outputting a valve control signal to the valve control unit to control the solenoid directional valve to perform the next action. Correspondingly, after the above step "determining that the solenoid directional valve is faulty", the fault diagnosis method for the solenoid directional valve in this application embodiment may further include the following steps: stopping the output of the valve control signal to the valve control unit and outputting an alarm signal.

[0058] Correspondingly, such as Figure 6 As shown, the core control unit 423 may also include an output subunit 4234 disposed between the fault diagnosis subunit 4232 and the valve control unit 421.

[0059] The output subunit 4234 is used to continuously output valve control signals to the valve control unit 421 after the fault diagnosis subunit 4232 determines that the solenoid directional valve 43 is normal, so as to control the solenoid directional valve 43 to perform the next action; or, after determining that the solenoid directional valve 43 is faulty, to stop outputting valve control signals to the valve control unit 421 and output an alarm signal.

[0060] It should be noted here that the alarm signal in this embodiment can be transmitted through... Figure 4 The human-computer interface 41 is output through display.

[0061] After determining that the solenoid directional valve 43 has malfunctioned, it is possible to further determine what specific malfunction has occurred in the solenoid directional valve 43, such as valve core jamming, coil burnout and short circuit, coil burnout and open circuit, spring breakage, and valve core lag.

[0062] As a feasible implementation method, the above step "determining the fault of electromagnetic directional valve 43" may specifically include the following steps to determine the valve core jamming fault: If the following conditions are met: the time for the current to reach a stable value in the input current change curve is less than the time for the current to reach a stable preset value in the standard current change curve, the maximum current value in the input current change curve is less than the maximum current value in the standard current change curve, the valve core does not move after the valve core signal is output, and the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve, then it is determined that the electromagnetic directional valve has a valve core jamming fault.

[0063] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may specifically include: a first fault diagnosis module 42321 connected to the generation subunit 4231 and the valve control unit 421 respectively.

[0064] The first fault diagnosis module 42321 is used to determine that the electromagnetic directional valve has a valve core jamming fault if the following conditions are met: the time for the current to reach a stable value in the input current change curve is less than the time for the current to reach a stable preset value in the standard current change curve; the maximum current value in the input current change curve is less than the maximum current value in the standard current change curve; the valve core does not move after the valve core signal is output; and the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve.

[0065] Specifically, such as Figure 7As shown, when the solenoid directional valve experiences a valve core jamming fault (i.e., the valve core is stuck and cannot move), the core control unit outputs a valve control signal. The valve control unit outputs a signal, energizing the coil of the solenoid directional valve. The coil voltage instantly increases to the rated voltage, and the coil circuit current increases. At this point, the coil magnetic force is less than the spring pressure, the valve core remains stuck, and the coil inductance remains unchanged. If the current is further increased, because the valve core is stuck, the coil inductance will not change, and the coil circuit current continues to increase to the stable current when the coil is not compressed (less than the rated current). When the valve control unit closes its output, the solenoid directional valve coil is de-energized, the coil voltage instantly drops to zero, and the coil circuit current gradually returns to zero without a plateau period.

[0066] As a feasible implementation, the above step "determining the fault of electromagnetic directional valve 43" may specifically include the following steps to determine the coil burnout and short circuit fault: If the following conditions are met: the time for the current to reach a stable value in the input current change curve is less than the time for the current to reach a stable preset value in the standard current change curve; the maximum current value in the input current change curve is greater than the maximum current value in the standard current change curve; the valve core does not move after the valve core signal is output; and the time for the voltage value in the output voltage change curve to match the preset voltage value in the standard voltage change curve is a preset response time, then it is determined that the electromagnetic directional valve has a coil burnout and short circuit fault.

[0067] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may specifically include a second fault diagnosis module 42322 that is connected to the generation subunit 4231 and the valve control unit 421 respectively.

[0068] The second fault diagnosis module 42322 is used to determine that the electromagnetic directional valve has a coil burnout and short circuit fault if the following conditions are met: the time for the current to reach a stable value in the input current change curve is less than the time for the current to reach a stable preset value in the standard current change curve; the maximum current value in the input current change curve is greater than the maximum current value in the standard current change curve; the valve core does not move after the valve core signal is output; and the time for the voltage value in the output voltage change curve to be consistent with the preset voltage value in the standard voltage change curve is a preset response time.

[0069] Specifically, such as Figure 8 As shown, when the solenoid directional valve experiences a coil burnout (short circuit) fault (i.e., the coil is damaged and cannot provide magnetic force, so the valve core cannot move), the core control unit outputs a valve control signal, the valve control unit outputs, the solenoid directional valve coil is energized, and the coil voltage instantly increases to the rated voltage. Due to the short circuit, the coil impedance is extremely small, and the coil circuit current is extremely large. At this time, the valve control unit shuts off the output due to short circuit protection, the solenoid directional valve coil loses power, the coil voltage instantly drops to zero, the coil circuit current also drops to zero very quickly, the coil cannot provide magnetic force, and the valve core does not move.

[0070] As a feasible implementation method, the above step "determining the fault of electromagnetic reversing valve 43" may specifically include the following steps to determine the coil burnout and open circuit fault: if the following conditions are met: the current in the input current change curve is continuously zero, the valve core does not move after the valve core signal is output, and the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve, then it is determined that the electromagnetic reversing valve has a coil burnout and open circuit fault.

[0071] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may specifically include a third fault diagnosis module 42323, which is connected to the generation subunit 4231 and the valve control unit 421 respectively.

[0072] The third fault diagnosis module 42323 is used to determine that the electromagnetic directional valve has a coil burnout and open circuit fault if the following conditions are met: the current in the input current change curve is always zero, the valve core does not move after the valve core signal is output, and the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve.

[0073] Specifically, such as Figure 9 As shown, when the solenoid directional valve experiences a coil burnout (open circuit) fault (i.e., the coil is damaged and cannot provide magnetic force, so the valve core cannot move), the core control unit outputs a valve control signal. The valve control unit outputs a signal, energizing the coil of the solenoid directional valve. The coil voltage instantly increases to the rated voltage. Due to the open circuit in the solenoid coil, the impedance is extremely high, and the coil circuit current is extremely small. The coil cannot provide magnetic force, and the valve core does not move. When the valve control unit closes its output, the coil of the solenoid directional valve is de-energized, and the coil voltage instantly drops to zero.

[0074] As a feasible implementation method, the above step "determining the fault of electromagnetic directional valve 43" may specifically include the following steps to determine the spring breakage fault: If the following conditions are met: the time for the current to reach a stable value in the input current change curve is less than the time for the current to reach a stable preset value in the standard current change curve; the maximum current value in the input current change curve is equal to the maximum current value in the standard current change curve; the time for the current in the input current change curve to recover from the stable value to zero is less than the preset response time; the valve core cannot stop moving after the valve core signal is output; and the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve, then it is determined that the electromagnetic directional valve has a spring breakage fault.

[0075] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may specifically include a fourth fault diagnosis module 42324, which is connected to the generation subunit 4231 and the valve control unit 421 respectively.

[0076] The fourth fault diagnosis module 42324 is used to determine that the solenoid directional valve has a spring breakage fault if the following conditions are met: the time for the current to reach a stable value in the input current change curve is less than the time for the current to reach a stable preset value in the standard current change curve; the maximum current value in the input current change curve is equal to the maximum current value in the standard current change curve; the time for the current in the input current change curve to recover from the stable value to zero is less than the preset response time; the valve core cannot stop moving after the valve core signal is output; and the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve.

[0077] Specifically, such as Figure 10 As shown, when a spring breakage occurs in the solenoid directional valve (i.e., the spring is damaged, the valve core cannot return to its original position after movement, and the directional action is incomplete), the core control unit outputs a valve control signal, the valve control unit outputs, and the coil of the solenoid directional valve is energized. The coil voltage increases instantaneously to the rated voltage. Because the spring is broken and cannot provide pressure, the coil circuit current increases, the valve core begins to move, the coil inductance increases, and the coil circuit current decreases or balances. After the valve core reaches its position, the coil inductance no longer changes, and the coil circuit current continues to increase to the coil's rated current. When the valve control unit closes its output, the coil of the solenoid directional valve is de-energized, the coil voltage drops instantaneously to zero, and because the spring is broken and the valve core cannot return to its original position, the coil circuit current gradually drops back to zero without a plateau period.

[0078] As a feasible implementation method, the above step "determining the fault of electromagnetic directional valve 43" may specifically include the following steps to determine the valve core hysteresis fault: If the following conditions are met: the current at any time in the input current change curve is less than the current at the same time in the standard current change curve; the time from the start to the stable state and from the stable state to the reset after the valve core signal is output is less than the preset response time; the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve; then it is determined that the electromagnetic directional valve has a valve core hysteresis fault.

[0079] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may specifically include a fifth fault diagnosis module 42325, which is connected to the generation subunit 4231 and the valve control unit 421 respectively.

[0080] The fifth fault diagnosis module 42325 is used to determine that the electromagnetic directional valve has a valve core hysteresis fault if the following conditions are met: the current at any time in the input current change curve is less than the current at the same time in the standard current change curve; the time from the start to the stable state and from the stable state to the reset after the valve core signal is output is less than the preset response time; and the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve.

[0081] Specifically, such as Figure 11 As shown, when the solenoid directional valve experiences a valve core lag (i.e., slowed valve core response due to idle corrosion, coil aging, valve body wear, etc.), the core control unit outputs a valve control signal. The valve control unit outputs, energizing the coil of the solenoid directional valve. The coil voltage instantly increases to the rated voltage, and the coil circuit current increases. Due to coil aging, the rate of increase in coil circuit current is less than during normal operation, and the corresponding rate of increase in coil magnetic force is also less than during normal operation. At this time, the coil magnetic force is less than the spring pressure, the valve core remains stationary, and the coil inductance remains unchanged. Continuing to increase the current, the coil magnetic force exceeds the spring pressure, and the valve core moves. Due to idle corrosion, valve body wear, etc., the frictional force of the valve core movement increases, and the valve core movement speed is less than during normal operation. Because the coil inductance increases, the current decreases or balances. After the valve core reaches its position, the coil inductance no longer changes, and the circuit current continues to increase to the stable current after coil aging (less than the rated current). When the valve control unit closes its output, the coil of the solenoid directional valve is de-energized, the coil voltage instantly drops to zero, the valve core resets, and the reset speed is less than during normal operation. The coil circuit current plateaus and returns to zero. Compared to normal operation, the coil circuit current and coil magnetic force decrease due to coil aging, while the friction of the valve core movement increases due to idle corrosion and valve body wear, resulting in a slower overall valve core response.

[0082] Furthermore, since the degree of valve core lag can reflect the aging trend of the solenoid directional valve to some extent, the operation and maintenance cycle of the solenoid directional valve can be set through the human-machine interface. The default is 6 months. A pop-up reminder can also be set for the hydraulic system's cumulative operating time before the operation and maintenance cycle, for example, 30, 15, 7, 3, 2, or 1 day before the operation and maintenance cycle. This information is stored in the core control unit, and the operation and maintenance cycle and the set time can be reset. Correspondingly, after the above step "determining that the solenoid directional valve has a valve core lag fault," the fault diagnosis method for the solenoid directional valve in this embodiment can further include the following steps: determining the aging value of the solenoid directional valve based on the time from the start to the stable state and from the stable state to the reset after the valve core signal is output; performing a weighted calculation on the aging value and the preset operation and maintenance cycle to obtain a corrected operation and maintenance cycle; and outputting a maintenance reminder signal or a replacement warning signal at a set time before the corrected operation and maintenance cycle is reached, based on the corrected operation and maintenance cycle.

[0083] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may further include a maintenance early warning module 42326 that is connected to the generation subunit 4231 and the fifth fault diagnosis module 42325 respectively.

[0084] The maintenance early warning module 42326 is used to determine the aging value of the solenoid directional valve based on the time it takes for the valve core to move from zero to a stable state and from a stable state to reset after the valve core signal is output; to perform a weighted calculation on the aging value and the preset operation and maintenance cycle to obtain the corrected operation and maintenance cycle; and to output a maintenance reminder signal or a replacement early warning signal at a set time before the corrected operation and maintenance cycle is reached, based on the corrected operation and maintenance cycle.

[0085] Furthermore, considering that prolonged disuse of the electromagnetic directional valve can easily lead to response lag, a low-frequency test cycle for the electromagnetic directional valve can be set via a human-machine interface, with a default value of 30 days, and stored in the core control unit. The low-frequency test cycle can also be reset. Correspondingly, the fault diagnosis method for the electromagnetic directional valve in this embodiment may further include the following steps: if the disuse time of the electromagnetic directional valve is detected to exceed the preset low-frequency test cycle, a valve control signal is output to the valve control unit corresponding to the electromagnetic directional valve in the non-working state.

[0086] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may also include a low-frequency test module 42327 connected to the valve control unit 421.

[0087] The low-frequency test module 42327 is used to detect that the non-use time of the solenoid directional valve exceeds the preset low-frequency test cycle, and then outputs a valve control signal to the valve control unit corresponding to the solenoid directional valve in the non-working state.

[0088] To clearly illustrate the fault diagnosis method of the electromagnetic directional valve in the embodiments of this application, the following is combined with... Figure 12 The overall process of the fault diagnosis method for the electromagnetic directional valve according to the embodiments of this application is described in detail.

[0089] like Figure 12 As shown, the fault diagnosis method for the electromagnetic directional valve in this application embodiment may specifically include the following steps:

[0090] S1201 outputs a valve control signal to the valve control unit to control the solenoid directional valve to start working.

[0091] S1202, determine whether the solenoid directional valve is being used for the first time. If yes, proceed to steps S1203 and S1204 respectively. If no, proceed to step S1205.

[0092] S1203: Set the alarm threshold range, operation and maintenance cycle, and low-frequency test cycle on the human-machine interface and store them in the core control unit. Execute steps S1206 and S1207 respectively.

[0093] S1204: Control the solenoid directional valve to learn itself and store the preset values ​​after learning in the core control unit. Execute step S1207.

[0094] S1205, Obtain the actual current, voltage, and valve core signal output status. Execute step S1207.

[0095] S1206, if the core control unit determines that the non-use time of the solenoid directional valve exceeds the preset low-frequency test cycle, then in the non-working state, it outputs a valve control signal to the valve control unit corresponding to the solenoid directional valve.

[0096] S1207, the core control unit determines whether the solenoid directional valve is faulty based on the actual current, voltage, valve core signal output status, valve parameters obtained through self-learning, and the range of alarm thresholds. If not, proceed to step S1208. If yes, proceed to step S1209.

[0097] S1208, the core control unit continuously outputs valve control signals to the valve control unit to control the solenoid directional valve to perform the next action.

[0098] S1209, the core control unit stops outputting valve control signals to the valve control unit and outputs alarm signals through the human-machine interface.

[0099] The fault diagnosis process for the solenoid directional valve during normal operation is as follows: Figure 13 As shown, it includes:

[0100] S1301, the core control unit makes judgments based on the actual current, voltage, valve core signal output status, and valve parameters obtained through self-learning.

[0101] S1302, Condition 1: I （实际） = I （预设值） .

[0102] S1303, Condition 2: Valve operation is normal.

[0103] S1304, Condition 3: U （实际） = U （预设值） .

[0104] If conditions 1-3 are all met, then proceed to step S1305.

[0105] S1305, the core control unit continuously outputs valve control signals to the valve control unit, the solenoid directional valve operates normally and enters the next action.

[0106] The fault diagnosis process for a stuck valve core in a solenoid directional valve is as follows: Figure 14 As shown, it includes:

[0107] S1401, the core control unit makes judgments based on the actual current, voltage, valve core signal output status, and valve parameters obtained through self-learning.

[0108] S1402, Condition 1: t （实际电流到达稳定值） <t （标准电流到达稳定预设值） , and I max（实际） <I max（预设值） .

[0109] S1403, Condition 2: Valve does not operate.

[0110] S1404, Condition 3: U （实际） = U （预设值） .

[0111] If conditions 1-3 are all met, then proceed to step S1405.

[0112] S1405, the core control unit stops outputting valve control signals to the valve control unit, the solenoid directional valve stops operating, and the human-machine interface outputs an alarm signal for valve core jamming fault.

[0113] The fault diagnosis process for a solenoid directional valve experiencing coil burnout (short circuit) is as follows: Figure 15 As shown, it includes:

[0114] S1501, the core control unit makes judgments based on the actual current, voltage, valve core signal output status, and valve parameters obtained through self-learning.

[0115] S1502, Condition 1: t （实际电流到达稳定值） <t （标准电流到达稳定预设值） , and I max（实际） >I max（预设值） This means that the current action time is extremely short and the maximum current preset value is much larger.

[0116] S1503, Condition 2: Valve does not operate.

[0117] S1504, Condition 3: U （实际） Only normal t （响应） , t （响应） The response time is determined by the response time set by the human-machine interface and the actual response time under normal working conditions through self-learning.

[0118] If conditions 1-3 are all met, then proceed to step S1505.

[0119] S1505, the core control unit stops outputting valve control signals to the valve control unit, the solenoid directional valve stops operating, and the human-machine interface outputs an alarm signal indicating a burnt-out (short-circuit) coil fault.

[0120] The fault diagnosis process for a solenoid directional valve experiencing coil burnout (open circuit) is as follows: Figure 16 As shown, it includes:

[0121] S1601, the core control unit makes judgments based on the actual current, voltage, valve core signal output status, and valve parameters obtained through self-learning.

[0122] S1602, Condition 1: I （实际） =0.

[0123] S1603, Condition 2: Valve does not operate.

[0124] S1604, Condition 3: U （实际） = U （预设值） .

[0125] If conditions 1-3 are all met, then proceed to step S1605.

[0126] S1605, the core control unit stops outputting valve control signals to the valve control unit, the solenoid directional valve stops operating, and the human-machine interface outputs an alarm signal indicating a burnt-out (open circuit) coil fault.

[0127] The fault diagnosis process for a broken spring in a solenoid directional valve is as follows: Figure 17 As shown, it includes:

[0128] S1701, the core control unit makes judgments based on the actual current, voltage, valve core signal output status, and valve parameters obtained through self-learning.

[0129] S1702, Condition 1: t （实际电流到达稳定值） <t （标准电流到达稳定预设值） , and I max（实际） =I max（预设值） , and t （实际关断输出电流） <t （响应） , t （响应） The response time is determined by the response time set by the human-machine interface and the actual response time under normal working conditions through self-learning.

[0130] S1703, Condition 2: Valve operation cannot be stopped.

[0131] S1704, Condition 3: U （实际） = U （预设值） .

[0132] If conditions 1-3 are all met, then proceed to step S1705.

[0133] S1705, the core control unit stops outputting valve control signals to the valve control unit, the solenoid directional valve stops operating, and the human-machine interface outputs an alarm signal for spring breakage fault.

[0134] The fault diagnosis process for a spool lag fault in an electromagnetic directional valve is as follows: Figure 18 As shown, it includes:

[0135] S1801, the core control unit makes judgments based on the actual current, voltage, valve core signal output status, and valve parameters obtained through self-learning.

[0136] S1802, Condition 1: I （各阶段实际电流） <I （各阶段电流预设值） .

[0137] S1803, Condition 2: Valve action response slows down.

[0138] S1804, Condition 3: U （实际） = U （预设值） .

[0139] If conditions 1-3 are all met, then proceed to step S1805.

[0140] S1805, the core control unit stops outputting valve control signals to the valve control unit, the solenoid directional valve stops operating, and the human-machine interface outputs an alarm signal for valve core hysteresis fault.

[0141] It should be noted that in diagnosing the various faults mentioned above (such as valve core jamming, coil burnout and short circuit, coil burnout and open circuit, spring breakage, and valve core lag), the "equal to" or "consistent" relationship between the actual current, voltage, and time values ​​and the preset current, voltage, and time values ​​is an ideal state. In practical applications, it is sufficient as long as the actual current, voltage, and time values ​​are within the preset range (e.g., 5% or 10%).

[0142] In summary, the fault diagnosis method for the electromagnetic directional valve in this application embodiment, by setting up a current detection unit, a voltage detection unit, a generation subunit, and a fault diagnosis subunit, can automatically diagnose faults in the electromagnetic directional valve based on the input current change curve and output voltage change curve of the valve control unit and the valve core signal output status of the electromagnetic directional valve. This allows for timely detection of electromagnetic directional valve faults and avoids safety hazards. Furthermore, it can automatically diagnose the type of fault in the electromagnetic directional valve, saving more time and effort compared to manual troubleshooting. The aging value of the electromagnetic directional valve is determined based on the degree of valve core hysteresis to correct the preset operation and maintenance cycle. A preventive maintenance reminder signal or replacement warning signal is output at a set time before the corrected operation and maintenance cycle is reached, preventing hydraulic system failure or erroneous operation of actuators due to electromagnetic directional valve faults, which could lead to equipment failure or even personnel hazards. If the electromagnetic directional valve is detected to have been unused for more than a preset low-frequency test cycle, the valve is controlled to operate in the non-operating state, preventing response lag caused by prolonged disuse.

[0143] This application also proposes a readable storage medium storing one or more computer programs, the one or more computer programs including instructions, which, when executed by a host computer or conversion unit, enable the host computer or conversion unit to perform various processes of any of the above-described embodiments of the fault diagnosis method for electromagnetic reversing valves.

[0144] The readable storage medium of this application embodiment, by setting up a current detection unit, a voltage detection unit, a generation subunit, and a fault diagnosis subunit, can automatically diagnose faults in the solenoid directional valve based on the input current change curve and output voltage change curve of the valve control unit and the valve core signal output status of the solenoid directional valve. This allows for timely detection of solenoid directional valve faults and avoidance of safety hazards. Furthermore, it can automatically diagnose the type of fault in the solenoid directional valve, saving time and effort compared to manual troubleshooting. The aging value of the solenoid directional valve is determined based on the degree of valve core hysteresis to correct the preset operation and maintenance cycle. A preventive maintenance reminder signal or replacement warning signal is output at a set time before the corrected operation and maintenance cycle is reached, preventing hydraulic system failure or erroneous operation of actuators due to solenoid directional valve faults, which could lead to equipment malfunctions or even personnel hazards. If the solenoid directional valve is detected to have been unused for more than a preset low-frequency test cycle, the valve is controlled to operate in the non-operating state, preventing response lag caused by prolonged disuse.

[0145] The systems, devices, modules, or units described in the above embodiments can be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, a computer can be, for example, a personal computer, laptop computer, cellular phone, camera phone, smartphone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or any combination of these devices.

[0146] For ease of description, the above devices are described separately by function as various units. Of course, in implementing this application, the functions of each unit can be implemented in one or more software and / or hardware.

[0147] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0148] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0149] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0150] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0151] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0152] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0153] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0154] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0155] This application can be described in the general context of computer-executable instructions, such as program modules, that are executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform a specific task or implement a specific abstract data type. This application can also be practiced in distributed computing environments where tasks are performed by remote processing devices connected via a communication network. In distributed computing environments, program modules can reside in local and remote computer storage media, including storage devices.

[0156] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0157] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A failure diagnosis method of an electromagnetic reversing valve, characterized by, include: Obtain the input current variation curve and output voltage variation curve of the valve control unit; The valve control unit obtains the valve core signal output status of the solenoid directional valve, and closes the valve core signal output when the solenoid directional valve is short-circuited. Based on the input current change curve, the output voltage change curve, and the valve core signal output status, fault diagnosis is performed on the electromagnetic reversing valve. The fault diagnosis of the electromagnetic directional valve based on the input current change curve, the output voltage change curve, and the valve core signal output state includes: If the following conditions are met: the current at any moment in the input current change curve is less than the current at the same moment in the standard current change curve; the time from the start to the stable state and from the stable state to the reset after the valve core signal is output is less than the preset response time; the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve; when the valve control unit closes the valve core signal output, the coil of the electromagnetic directional valve is de-energized; the voltage value in the output voltage change curve drops to zero instantaneously; the valve core resets and the reset speed is less than the reset speed during normal operation; and the current value in the input current change curve drops back to zero after a plateau period, then it is determined that the electromagnetic directional valve has a valve core hysteresis fault. If the following conditions are met: the time for the current in the input current change curve to reach a stable value is less than the time for the current in the standard current change curve to reach a stable preset value; the maximum current value in the input current change curve is greater than the maximum current value in the standard current change curve; the valve core does not move after the valve core signal is output; and the time for the voltage value in the output voltage change curve to match the preset voltage value in the standard voltage change curve is a preset response time, then it is determined that the electromagnetic reversing valve has a coil burnout and short circuit fault. The standard current change curve and the standard voltage change curve are curves when the electromagnetic directional valve is working normally.

2. The fault diagnosis method according to claim 1, characterized in that, The fault diagnosis of the electromagnetic directional valve based on the input current change curve, the output voltage change curve, and the valve core signal output state includes: Obtain the standard current change curve, standard voltage change curve, and standard valve core signal output status when the electromagnetic directional valve is operating normally; If the input current change curve, the output voltage change curve, and the valve core signal output state are consistent with the standard current change curve, the standard voltage change curve, and the standard valve core signal output state, respectively, then the electromagnetic reversing valve is determined to be normal. If the input current change curve, the output voltage change curve, and the valve core signal output state are inconsistent with at least one of the standard current change curve, the standard voltage change curve, and the standard valve core signal output state, then the electromagnetic directional valve is determined to be faulty.

3. The fault diagnosis method according to claim 2, characterized in that, After confirming that the electromagnetic reversing valve is functioning normally, the process further includes: A valve control signal is continuously output to the valve control unit to control the solenoid directional valve to perform the next action; After determining that the electromagnetic reversing valve is faulty, the process further includes: Stop outputting the valve control signal to the valve control unit and output an alarm signal.

4. The fault diagnosis method according to claim 2, characterized in that, The determination of the solenoid directional valve malfunction includes: If the following conditions are met: the time for the current to reach a stable value in the input current change curve is less than the time for the current to reach a stable preset value in the standard current change curve; the maximum current value in the input current change curve is less than the maximum current value in the standard current change curve; the valve core does not move after the valve core signal is output; and the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve, then it is determined that the electromagnetic directional valve has a valve core jamming fault.

5. The fault diagnosis method according to claim 2, characterized in that, The determination of the solenoid directional valve malfunction includes: If the following conditions are met: the current in the input current change curve is continuously zero, the valve core does not move after the valve core signal is output, and the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve, then it is determined that the electromagnetic reversing valve has a coil burnout and open circuit fault.

6. The fault diagnosis method according to claim 2, characterized in that, The determination of the solenoid directional valve malfunction includes: If the following conditions are met: the time for the current to reach a stable value in the input current change curve is less than the time for the current to reach a stable preset value in the standard current change curve; the maximum current value in the input current change curve is equal to the maximum current value in the standard current change curve; the time for the current in the input current change curve to recover from a stable value to zero is less than a preset response time; the valve core cannot stop moving after the valve core signal is output; and the voltage value in the output voltage change curve is consistent with the preset voltage value in the standard voltage change curve, then it is determined that the electromagnetic reversing valve has a spring breakage fault.

7. The fault diagnosis method according to claim 1, characterized in that, After determining that the electromagnetic directional valve has a spool hysteresis fault, the method further includes: The aging value of the solenoid directional valve is determined based on the time from the start of the valve core action to the stable state and from the stable state to the reset after the valve core signal is output. The aging value and the preset operation and maintenance cycle are weighted and calculated to obtain the corrected operation and maintenance cycle; Based on the revised operation and maintenance cycle, a maintenance reminder signal or a replacement warning signal is output at a set time before the revised operation and maintenance cycle is reached.

8. The fault diagnosis method according to claim 1, characterized in that, Also includes: If the non-use time of the electromagnetic directional valve exceeds the preset low-frequency test cycle, a valve control signal is output to the valve control unit corresponding to the electromagnetic directional valve in the non-working state.

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