Fault diagnosis method of electromagnetic reversing valve

Abstract

The invention discloses a fault diagnosis method for 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, and acquiring a valve core signal output state of an electromagnetic reversing valve; according to the input current change curve, the output voltage change curve and the valve element signal output state, fault diagnosis is conducted on the electromagnetic reversing valve. According to the input current change curve and the output voltage change curve of the valve control unit and the valve element signal output state of the electromagnetic reversing valve, fault diagnosis of the electromagnetic reversing valve can be automatically achieved, so that faults of the electromagnetic reversing valve are found in time, and potential safety hazards are avoided.

Description

Technical Field

[0001] The present application relates to the technical field of electromagnetic reversing valves, and in particular to a fault diagnosis method for electromagnetic reversing valves. Background Art

[0002] As the core control element of hydraulic and pneumatic systems, electromagnetic reversing valves have a wide range of application scenarios in the field of industrial automation. The electromagnetic reversing valve is mainly composed of valve body, spring, valve core, coil and other components. It drives the valve core to move through electromagnetic force to switch the hydraulic oil passage, guide the hydraulic oil to transmit power, and realize different mechanical action requirements.

[0003] In actual production applications, manual troubleshooting and replacement are usually performed only when the electromagnetic reversing valve is damaged and affects the action of the actuator. This method relies on manual fault detection, especially when a machine usually requires the use of multiple electromagnetic reversing valves. Therefore, it is easy to cause electromagnetic reversing valve faults to be discovered untimely, posing a safety hazard. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a fault diagnosis method for an electromagnetic reversing valve, so as to solve the problem that manual fault discovery may easily lead to untimely fault discovery of the electromagnetic reversing valve and potential safety hazards.

[0005] To achieve the above objectives, the present application embodiment adopts the following technical solutions: In a first aspect, an embodiment of the present application provides a fault diagnosis method for an electromagnetic reversing valve, comprising: obtaining an input current change curve and an output voltage change curve of a valve control unit; obtaining 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.

[0006] At least one of the above technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects: When diagnosing the fault of the electromagnetic reversing valve, the embodiment of the present application obtains the input current change curve and the output voltage change curve of the valve control unit, as well as the valve core signal output state of the electromagnetic reversing valve, and diagnoses the fault of the electromagnetic reversing valve according to the input current change curve, the output voltage change curve and the valve core signal output state. The embodiment of the present application can automatically diagnose the fault of the electromagnetic reversing valve 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, so as to timely discover the fault of the electromagnetic reversing valve and avoid safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1 A schematic flow chart of a fault diagnosis method for an electromagnetic reversing valve provided in accordance with an embodiment of the present application; Figure 2 It is a structural schematic diagram of a three-position four-way electromagnetic reversing valve; Figure 3 It is a schematic diagram of the principle of a three-position four-way electromagnetic reversing valve; Figure 4 A schematic diagram of the structure of a fault diagnosis system for an electromagnetic reversing valve provided in one embodiment of the present application; Figure 5 A schematic diagram of a standard current variation curve and a standard voltage variation curve when the electromagnetic reversing valve provided in one embodiment of the present application is working normally; Figure 6 A schematic diagram of the structure of a core control unit provided for one embodiment of the present application; Figure 7 A schematic diagram of a current change curve and a voltage change curve when a valve core stuck fault occurs in an electromagnetic reversing valve provided by an embodiment of the present application; Figure 8 A schematic diagram of a current change curve and a voltage change curve when a solenoid reversing valve has a coil burnout (short circuit) fault provided by an embodiment of the present application; Fig. 9 A schematic diagram of a current change curve and a voltage change curve when a solenoid reversing valve has a coil burnout (circuit break) fault provided by an embodiment of the present application; Fig.10 A schematic diagram of a current variation curve and a voltage variation curve when a spring breakage fault occurs in an electromagnetic reversing valve provided by an embodiment of the present application; Fig.11 A schematic diagram of a current change curve and a voltage change curve when a valve core hysteresis fault occurs in an electromagnetic reversing valve provided by an embodiment of the present application; Fig.12 A schematic diagram of the overall flow of a fault diagnosis method for an electromagnetic reversing valve provided in another embodiment of the present application; Fig.13 A schematic diagram of a fault diagnosis process when a solenoid reversing valve is operating normally provided by an embodiment of the present application; Fig.14 A schematic diagram of a fault diagnosis process when a valve core stuck fault occurs in a solenoid reversing valve provided by an embodiment of the present application; Fig.15A schematic diagram of a fault diagnosis process when a solenoid reversing valve has a coil burnout (short circuit) fault provided by an embodiment of the present application; Fig.16 A schematic diagram of a fault diagnosis process when a solenoid reversing valve has a coil burnout (open circuit) fault provided by an embodiment of the present application; Fig.17 A schematic diagram of a fault diagnosis process when a spring breakage fault occurs in an electromagnetic reversing valve provided by an embodiment of the present application; Fig.18 A schematic diagram of a fault diagnosis process when a valve core hysteresis fault occurs in an electromagnetic reversing valve provided in an embodiment of the present application. DETAILED DESCRIPTION

[0008] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0009] The terms "first", "second", etc. in this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here. In addition, the "and / or" in this application represents at least one of the connected objects, and the character " / " generally represents that the front and back associated objects are in an "or" relationship. It should be noted that the data involved in this application are all obtained on the premise of obtaining user authorization.

[0010] The technical solutions provided by various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0011] Figure 1 A schematic diagram of a flow chart of a fault diagnosis method for an electromagnetic reversing valve provided in one embodiment of the present application. Figure 1 As shown, the fault diagnosis method of the electromagnetic reversing valve in the embodiment of the present application may specifically include the following steps: S101, obtaining an input current variation curve and an output voltage variation curve of a valve control unit.

[0012] S102, obtaining the valve core signal output state of the electromagnetic reversing valve.

[0013] S103, performing fault diagnosis on the electromagnetic reversing valve according to the input current variation curve, the output voltage variation curve and the valve core signal output state.

[0014] In the embodiment of the present application, the executor of the fault diagnosis method of the electromagnetic reversing valve in the embodiment of the present application may be the core control unit in the fault diagnosis system of the electromagnetic reversing valve provided in the embodiment of the present application, and the fault diagnosis system of the electromagnetic reversing valve may be applied to mechanical equipment such as sanding machines and injection molding machines.

[0015] The electromagnetic reversing valve in the embodiment of the present application can be specifically Figure 2 The three-position four-way electromagnetic reversing valve shown in the figure is not limited in detail in the present embodiment. Figure 2 As shown, the three-position four-way solenoid directional valve includes: a valve body 1, a spring 2, a spring seat 3, a valve core 4, a coil 5, an armature 6, a spacer sleeve 7, a housing 8 and a plug assembly 9.

[0016] like Figure 3 As shown, when the coil in the electromagnetic reversing valve is energized, it generates magnetic force to attract the valve core to overcome the spring pressure and move. The movement of the valve core is used to switch different flow channels to achieve the purpose of controlling the flow direction of the oil.

[0017] Figure 4 This is a schematic diagram of the structure of the fault diagnosis system of the electromagnetic reversing valve provided in the embodiment of the present application. Figure 4 As shown, the fault diagnosis system of the electromagnetic reversing valve of the embodiment of the present 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.

[0018] 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.

[0019] The human-machine interface 41 can realize the interactive functions between personnel and data display, action operation, parameter setting, etc. of the fault diagnosis system through key and touch screen input and screen display output.

[0020] The controller 42 can collect and control the position, temperature, and status of each component in mechanical equipment such as a sanding machine and an injection molding machine through the built-in analog quantity, digital quantity input, output port and core control unit 423, so as to realize the movement of each component mechanism in mechanical equipment such as a sanding machine and an injection molding machine as required and realize the corresponding function.

[0021] The power supply 422 is used to supply power to the valve control unit 421. The power supply 422 is generally externally input direct current with a voltage value of 24V±10%.

[0022] The core control unit 423 is used to output valve control signals to the valve control unit 421 according to the normal action sequence of mechanical equipment such as sanding machines and injection molding machines. The core control unit 423 can use an embedded processor, which is embedded with functional modules related to the embodiments of the present application.

[0023] The valve control unit 421 is used to output a valve core signal to control the coil of the electromagnetic reversing valve 43 to be energized, de-energized, or maintain the current state according to the valve control signal output by the core control unit 423, using the power switch technology, so as to control the action of the electromagnetic reversing valve 43. The valve control unit 421 may have built-in overcurrent and overtemperature protection, and when the control load is short-circuited, the output will be turned off. Both the valve control unit 421 and the electromagnetic reversing valve 43 can be one or more, and multiple valve control units 421 correspond to multiple electromagnetic reversing valves 43.

[0024] 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 electromagnetic reversing valve 43 , and input it to the core control unit 423 .

[0025] The voltage detection unit 425 is used to collect the output voltage U of the valve control unit 421 in real time, that is, to collect the coil voltage U of the electromagnetic reversing valve 43 , and input it to the core control unit 423 .

[0026] The generating sub-unit 4231 is used to generate an input current variation curve I(t) according to the input current I of the valve control unit 421 collected by the current detecting unit 424, to generate an output voltage variation curve U(t) according to the output voltage U of the valve control unit 421 collected by the voltage detecting unit 425, and to generate a valve core signal output state according to the feedback of the action executing component after the valve core signal is output.

[0027] The fault diagnosis subunit 4232 is used to perform fault diagnosis on the electromagnetic reversing valve 43 according to the input current variation curve I(t), the output voltage variation curve U(t) and the valve core signal output state.

[0028] The above step S103 "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" may specifically include the following steps: Obtain a standard current change curve, a standard voltage change curve and a standard valve core signal output state when the solenoid reversing valve is working normally; if the input current change curve, the output voltage change curve and the valve core signal output state are respectively consistent with the standard current change curve, the standard voltage change curve and the standard valve core signal output state, the solenoid reversing valve is determined to be normal; if at least one of the input current change curve, the output voltage change curve and the valve core signal output state is inconsistent with the standard current change curve, the standard voltage change curve and the standard valve core signal output state, the solenoid reversing valve is determined to be faulty.

[0029] Among them, the standard current change curve I of the electromagnetic reversing valve when it is working normally 0 (t), standard voltage change curve U 0 (t) and the standard valve core signal output state can be obtained through valve parameter self-learning when the electromagnetic reversing valve is used for the first time, and stored in the core control unit. Valve parameter self-learning: When the electromagnetic reversing valve is used for the first time, when the system is in the pressure relief state, the core control unit outputs the valve control signal in sequence, and the valve control unit outputs the control solenoid reversing valve action, samples the current, voltage and valve core signal output of each electromagnetic reversing valve, and the feedback of the action execution component, and saves the collected data into the core control unit as the preset value after self-learning. When the electromagnetic reversing valve is not used for the first time, execute the fault diagnosis process of the embodiment of the present application.

[0030] Figure 5 The following is a schematic diagram of the standard current change curve and standard voltage change curve when the electromagnetic reversing valve is working normally. Figure 5 As shown, the core control unit outputs the valve control signal, the valve control unit outputs, the coil of the electromagnetic reversing valve is energized, and the coil voltage instantly increases to the rated voltage. According to the working principle of the electromagnetic reversing valve, due to the inductance effect of the coil, the coil loop current increases. At this time, the coil magnetic force is less than the spring pressure, the valve core does not move, and the coil inductance remains unchanged; continue to increase the current, the coil magnetic force is greater than the spring pressure, the valve core moves, the coil inductance increases, and the current decreases or balances; after the valve core is in place, the coil inductance no longer changes, and the loop current continues to increase to the rated current of the coil. When the valve control unit closes the output, the coil of the electromagnetic reversing valve loses power, the coil voltage instantly drops to zero, the valve core resets, and the coil loop current drops to zero after a plateau period.

[0031] In addition, when the electromagnetic reversing valve is used for the first time, the range of the alarm threshold value, such as the current and voltage, response time, difference range threshold, etc., can also be set through the human-machine interface and stored in the core control unit 423. The difference range threshold system defaults to 10%. When the core control unit 423 determines that the difference range between the collected input current, output voltage and the valve parameter obtained by self-learning exceeds the difference range threshold, an alarm signal is output. For example, the collected input current is 0.9 amperes (A), and the input current preset value obtained by 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.

[0032] Correspondingly, such as Figure 6 As shown, Figure 4 The core control unit 423 may further include: a storage subunit 4233 connected to the fault diagnosis subunit 4232.

[0033] The storage subunit 4233 is used to store a standard current variation curve, a standard voltage variation curve and a standard valve core signal output state when the electromagnetic reversing valve is working normally.

[0034] The fault diagnosis subunit 4232 is specifically used for: if the input current change curve, the output voltage change curve and the valve core signal output state are respectively consistent with the standard current change curve, the standard voltage change curve and the standard valve core signal output state, then the solenoid reversing valve 43 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 solenoid reversing valve 43 is determined to be faulty.

[0035] Further, after the above step of "determining that the electromagnetic reversing valve is normal", the electromagnetic reversing valve fault diagnosis method of the embodiment of the present application may also include the following steps: continuously outputting the valve control signal to the valve control unit to control the electromagnetic reversing valve to perform the next action. After the corresponding above step of "determining that the electromagnetic reversing valve is faulty", the electromagnetic reversing valve fault diagnosis method of the embodiment of the present application may also include the following steps: stopping outputting the valve control signal to the valve control unit and outputting an alarm signal.

[0036] Correspondingly, such as Figure 6 As shown, the core control unit 423 may further include: an output subunit 4234 disposed between the fault diagnosis subunit 4232 and the valve control unit 421 .

[0037] The output subunit 4234 is used to continuously output the valve control signal to the valve control unit 421 to control the solenoid reversing valve 43 to perform the next action after the fault diagnosis subunit 4232 determines that the solenoid reversing valve 43 is normal; or, after determining that the solenoid reversing valve 43 is faulty, stop outputting the valve control signal to the valve control unit 421 and output an alarm signal.

[0038] It should be noted that the alarm signal in the embodiment of the present application can be Figure 4 The human-machine interface 41 is outputted in a display manner.

[0039] After determining that the electromagnetic reversing valve 43 has a fault, it is possible to further determine what specific fault the electromagnetic reversing valve 43 has, such as a valve core stuck fault, a coil burned and short circuit fault, a coil burned and open circuit fault, a spring breakage fault, and a valve core hysteresis fault.

[0040] As a feasible implementation method, the above-mentioned step of "determining the fault of the electromagnetic reversing valve 43" may specifically include the following steps to determine the valve core stuck 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 reversing valve has a valve core stuck fault.

[0041] 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.

[0042] The first fault diagnosis module 42321 is used to determine that the electromagnetic reversing valve has a valve core stuck 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.

[0043] Specifically, Figure 7 As shown, when the solenoid reversing valve has a valve core stuck (i.e. the valve core is stuck and cannot move), the core control unit outputs the valve control signal, the valve control unit outputs, the coil of the solenoid reversing valve is energized, the coil voltage instantly increases to the rated voltage, the coil loop current increases, at this time the coil magnetic force is less than the spring pressure, the valve core is stuck and does not move, and the coil inductance remains unchanged; continue to increase the current, because the valve core is stuck, the coil inductance will not change, and the coil loop 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 the output, the coil of the solenoid reversing valve loses power, the coil voltage instantly drops to zero, and the coil loop current gradually drops to zero without a plateau period.

[0044] As a feasible implementation method, the above-mentioned step of "determining the fault of the electromagnetic reversing 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 be consistent with the preset voltage value in the standard voltage change curve is the preset response time, then it is determined that the electromagnetic reversing valve has a coil burnout and short circuit fault.

[0045] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may specifically include: a second fault diagnosis module 42322 connected to the generation subunit 4231 and the valve control unit 421 respectively.

[0046] The second fault diagnosis module 42322 is used to determine that the electromagnetic reversing valve has a coil burnt out and a short circuit 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 be consistent with the preset voltage value in the standard voltage change curve is the preset response time.

[0047] Specifically, Figure 8 As shown, when the solenoid reversing valve has a coil burnout (short circuit) (i.e., the coil is damaged and cannot provide magnetic force, and the valve core cannot move), the core control unit outputs a valve control signal, the valve control unit outputs, the coil of the solenoid reversing valve is energized, and the coil voltage instantly increases to the rated voltage. Because the coil is short-circuited, the impedance is extremely small, and the coil loop current is extremely large. At this time, the valve control unit closes the output due to short-circuit protection, the coil of the solenoid reversing valve loses power, the coil voltage instantly drops to zero, the coil loop current also quickly drops to zero, the coil cannot provide magnetic force, and the valve core does not move.

[0048] As a feasible implementation method, the above-mentioned step of "determining the fault of the electromagnetic reversing valve 43" may specifically include the following steps to determine the coil burnout and circuit breakage 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 circuit breakage fault.

[0049] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may specifically include: a third fault diagnosis module 42323 connected to the generation subunit 4231 and the valve control unit 421 respectively.

[0050] The third fault diagnosis module 42323 is used to determine that the solenoid reversing valve has a coil burnt out and a circuit breaker 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.

[0051] Specifically, Fig. 9As shown in the figure, when the electromagnetic reversing valve has a coil burnout (open circuit) (i.e. the coil is damaged and cannot provide magnetic force, and the valve core cannot move), the core control unit outputs the valve control signal, the valve control unit outputs, the coil of the electromagnetic reversing valve is energized, and the coil voltage instantly increases to the rated voltage. Because the electromagnetic coil is open circuit, the impedance is extremely large, the coil loop current is extremely small, the coil cannot provide magnetic force, and the valve core does not move. When the valve control unit closes the output, the coil of the electromagnetic reversing valve loses power, and the coil voltage instantly drops to zero.

[0052] As a feasible implementation method, the above-mentioned step of "determining the fault of the electromagnetic reversing 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 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 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 movement cannot stop 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.

[0053] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may specifically include: a fourth fault diagnosis module 42324 connected to the generation subunit 4231 and the valve control unit 421 respectively.

[0054] The fourth fault diagnosis module 42324 is used to determine that the electromagnetic reversing valve has a spring break 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 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 the preset response time, the valve core movement cannot be stopped 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.

[0055] Specifically, Fig.10As shown, when the electromagnetic reversing valve has a spring break (i.e., the spring is damaged, the valve core cannot be reset after movement, and the reversing action is incomplete), the core control unit outputs the valve control signal, the valve control unit outputs, the coil of the electromagnetic reversing valve is energized, and the coil voltage instantly increases to the rated voltage. Since the spring is broken and cannot provide pressure, the coil loop current increases, the valve core begins to move, the coil inductance increases, and the coil loop current decreases or balances; after the valve core is in place, the coil inductance no longer changes, and the coil loop current continues to increase to the coil rated current. When the valve control unit closes the output, the coil of the electromagnetic reversing valve loses power, and the coil voltage instantly drops to zero. Since the spring is broken, the valve core cannot be reset, and the coil loop current gradually drops to zero without going through a plateau period.

[0056] As a feasible implementation method, the above-mentioned step of "determining the fault of the electromagnetic reversing 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 for the valve core action 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, then it is determined that the electromagnetic reversing valve has a valve core hysteresis fault.

[0057] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may specifically include: a fifth fault diagnosis module 42325 connected to the generation subunit 4231 and the valve control unit 421 respectively.

[0058] The fifth fault diagnosis module 42325 is used to determine that the electromagnetic reversing 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 for the valve core movement 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.

[0059] Specifically, Fig.11As shown in the figure, when the solenoid reversing valve has a valve core hysteresis fault (i.e., the valve core response slows down due to idle corrosion, coil aging, valve body wear, etc.), the core control unit outputs the valve control signal, the valve control unit outputs, the coil of the solenoid reversing valve is energized, the coil voltage increases to the rated voltage instantly, the coil loop current increases, and the coil loop current growth rate is lower than that in normal operation due to coil aging, etc., and the corresponding coil magnetic force growth rate is lower than that in normal operation. At this time, the coil magnetic force is lower than the spring pressure, the valve core does not move, and the coil inductance remains unchanged; continue to increase the current, the coil magnetic force is higher than the spring pressure, the valve core moves, the friction of the valve core movement increases due to idle corrosion, valve body wear, etc., the valve core movement speed is lower than that in normal operation, and the current decreases or balances due to the increase in coil inductance; after the valve core is in place, the coil inductance no longer changes, and the loop current continues to increase to the stable current after coil aging (less than the rated current). When the valve control unit closes the output, the coil of the solenoid reversing valve loses power, the coil voltage drops to zero instantly, the valve core resets, and the reset speed is lower than that in normal operation. The coil loop current falls back to zero after a plateau period. Compared with normal operation, the coil loop current and coil magnetic force become smaller due to coil aging, and the friction of valve core movement increases due to idle rust and valve body wear, resulting in a slower valve core response overall.

[0060] Furthermore, since the degree of valve core hysteresis can reflect the aging trend of the electromagnetic reversing valve to a certain extent, the operation and maintenance cycle of the electromagnetic reversing valve can also be set through the human-machine interface, and the default is 6 months. It is also possible to set a pop-up reminder when the cumulative operation time of the hydraulic system reaches the set time before the operation and maintenance cycle, such as 30, 15, 7, 3, 2 or 1 day before the operation and maintenance cycle, and store it in the core control unit. The operation and maintenance cycle and the set time can also be reset. Correspondingly, after the above step of "determining that the electromagnetic reversing valve has a valve core hysteresis fault", the fault diagnosis method of the electromagnetic reversing valve of the embodiment of the present application can also include the following steps: determining the aging value of the electromagnetic reversing valve according to the time from the start to the stable state and from the stable state to the reset of the valve core action after the valve core signal is output; performing weighted calculation on the aging value and the preset operation and maintenance cycle to obtain a corrected operation and maintenance cycle; according to the corrected operation and maintenance cycle, outputting a maintenance reminder signal or a replacement warning signal at the set time before reaching the corrected operation and maintenance cycle.

[0061] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may further include: a maintenance warning module 42326 connected to the generation subunit 4231 and the fifth fault diagnosis module 42325 respectively.

[0062] The maintenance warning module 42326 is used to determine the aging value of the electromagnetic reversing 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; perform weighted calculation on the aging value and the preset operation and maintenance cycle to obtain a corrected operation and maintenance cycle; and output a maintenance reminder signal or a replacement warning signal based on the corrected operation and maintenance cycle at a set time before reaching the corrected operation and maintenance cycle.

[0063] Furthermore, considering that the electromagnetic reversing valve is not used for a long time, it is easy to cause response hysteresis, so the low-frequency test cycle of the electromagnetic reversing valve can also be set through the human-machine interface, which is 30 days by default and stored in the core control unit. The low-frequency test cycle can also be reset. Correspondingly, the fault diagnosis method of the electromagnetic reversing valve of the embodiment of the present application can also include the following steps: when it is detected that the electromagnetic reversing valve has not been used for more than the preset low-frequency test cycle, a valve control signal is output to the valve control unit corresponding to the electromagnetic reversing valve in the non-working state.

[0064] Correspondingly, such as Figure 6 As shown, the fault diagnosis subunit 4232 may further include: a low frequency test module 42327 connected to the valve control unit 421 .

[0065] The low-frequency test module 42327 is used to detect that the electromagnetic reversing valve has not been used for a period of time exceeding a preset low-frequency test period, and then output a valve control signal to the valve control unit corresponding to the electromagnetic reversing valve in a non-working state.

[0066] To clearly illustrate the fault diagnosis method of the electromagnetic reversing valve in the embodiment of the present application, Fig.12 The overall process of the fault diagnosis method of the electromagnetic reversing valve in the embodiment of the present application is described in detail.

[0067] like Fig.12 As shown, the fault diagnosis method of the electromagnetic reversing valve in the embodiment of the present application may specifically include the following steps: S1201, output valve control signal to the valve control unit to control the solenoid reversing valve to start working.

[0068] S1202, determine whether the electromagnetic reversing valve is used for the first time. If yes, execute steps S1203 and S1204 respectively. If no, execute step S1205.

[0069] S1203, set the range of alarm threshold, operation maintenance cycle and low frequency test cycle in the human-machine interface, and store them in the core control unit. Execute steps S1206 and S1207 respectively.

[0070] S1204, control the electromagnetic reversing valve to self-learn, and store the preset value after self-learning in the core control unit. Execute step S1207.

[0071] S1205, obtaining the actual current, voltage and valve core signal output state. Execute step S1207.

[0072] S1206, the core control unit determines that the unused time of the electromagnetic reversing valve exceeds the preset low-frequency test cycle, and then outputs a valve control signal to the valve control unit corresponding to the electromagnetic reversing valve in a non-working state.

[0073] S1207, the core control unit determines whether the electromagnetic reversing valve is faulty according to the actual current, voltage, valve core signal output state, valve parameters obtained by self-learning and the range of the alarm threshold. If not, execute step S1208. If yes, execute step S1209.

[0074] S1208, the core control unit continuously outputs the valve control signal to the valve control unit to control the electromagnetic reversing valve to perform the next action.

[0075] S1209, the core control unit stops outputting valve control signals to the valve control unit, and outputs an alarm signal through the human-machine interface.

[0076] Among them, the fault diagnosis process of the electromagnetic reversing valve when it is working normally is as follows Fig.13 As shown, including: S1301, the core control unit makes a judgment based on the actual current, voltage and valve core signal output state and the valve parameters obtained by self-learning.

[0077] S1302, Condition 1: I （实际） = I （预设值） .

[0078] S1303, condition 2: the valve action is performed normally.

[0079] S1304, Condition 3: U （实际） = U （预设值） .

[0080] If conditions 1-3 are all met, execute step S1305.

[0081] S1305, the core control unit continuously outputs the valve control signal to the valve control unit, and the electromagnetic reversing valve operates normally and enters the next action.

[0082] Among them, the fault diagnosis process when the solenoid reversing valve has a valve core stuck fault is as follows: Fig.14 As shown, including: S1401, the core control unit makes a judgment based on the actual current, voltage and valve core signal output state and the valve parameters obtained by self-learning.

[0083] 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） .

[0084] S1403, condition 2: the valve does not move.

[0085] S1404, Condition 3: U （实际） = U （预设值） .

[0086] If conditions 1-3 are all met, execute step S1405.

[0087] S1405, the core control unit stops outputting valve control signals to the valve control unit, the solenoid reversing valve stops moving, and the human-machine interface outputs an alarm signal of a valve core stuck fault.

[0088] Among them, the fault diagnosis process when the solenoid reversing valve has a coil burnout (short circuit) fault is as follows: Fig.15 As shown, including: S1501, the core control unit makes a judgment based on the actual current, voltage and valve core signal output state and the valve parameters obtained by self-learning.

[0089] 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） , that is, the current action time is extremely short and the maximum current preset value is much larger.

[0090] S1503, condition 2: the valve does not move.

[0091] S1504, Condition 3: U （实际） Normal t only （响应） , t （响应） It is determined by the response time set by the human-machine interface and the actual response time under normal working of self-learning.

[0092] If conditions 1-3 are all met, execute step S1505.

[0093] S1505, the core control unit stops outputting valve control signals to the valve control unit, the electromagnetic reversing valve stops moving, and the human-machine interface outputs an alarm signal of coil burnout (short circuit) fault.

[0094] Among them, the fault diagnosis process when the solenoid reversing valve has a coil burnout (circuit break) fault is as follows: Fig.16 As shown, including: S1601, the core control unit makes a judgment based on the actual current, voltage and valve core signal output state and the valve parameters obtained by self-learning.

[0095] S1602, Condition 1: I （实际）=0.

[0096] S1603, condition 2: valve does not move.

[0097] S1604, Condition 3: U （实际） = U （预设值） .

[0098] If conditions 1-3 are all met, execute step S1605.

[0099] S1605, the core control unit stops outputting valve control signals to the valve control unit, the electromagnetic reversing valve stops moving, and the human-machine interface outputs an alarm signal of coil burnout (open circuit) failure.

[0100] Among them, the fault diagnosis process when the electromagnetic reversing valve has a spring break fault is as follows: Fig.17 As shown, including: S1701, the core control unit makes a judgment based on the actual current, voltage and valve core signal output state and the valve parameters obtained by self-learning.

[0101] 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） It is determined by the response time set by the human-machine interface and the actual response time under normal working of self-learning.

[0102] S1703, condition 2: Valve action cannot be stopped.

[0103] S1704, Condition 3: U （实际） = U （预设值） .

[0104] If conditions 1-3 are all met, execute step S1705.

[0105] S1705, the core control unit stops outputting valve control signals to the valve control unit, the solenoid reversing valve stops moving, and the human-machine interface outputs an alarm signal of a spring break failure.

[0106] Among them, the fault diagnosis process when the solenoid reversing valve has a valve core hysteresis fault is as follows: Fig.18 As shown, including: S1801, the core control unit makes a judgment based on the actual current, voltage and valve core signal output state and the valve parameters obtained by self-learning.

[0107] S1802, Condition 1: I （各阶段实际电流） <I （各阶段电流预设值） .

[0108] S1803, condition 2: the valve action response becomes slow.

[0109] S1804, condition 3: U （实际） = U （预设值） .

[0110] If conditions 1-3 are all met, execute step S1805.

[0111] S1805, the core control unit stops outputting valve control signals to the valve control unit, the solenoid reversing valve stops moving, and the human-machine interface outputs an alarm signal of valve core hysteresis failure.

[0112] It should be noted here that in the diagnosis of the above-mentioned faults (such as valve core sticking fault, coil burnout and short circuit fault, coil burnout and open circuit fault, spring breakage fault and valve core hysteresis fault), the "equal" or "consistent" relationship between the actual current value, voltage value, time and the preset current value, voltage value, time is an ideal state. In practical applications, as long as the actual current value, voltage value, time is within the set range (for example, 5%, 10%) near the preset current value, voltage value, time, it will be fine.

[0113] In summary, the fault diagnosis method of the electromagnetic reversing valve in the embodiment of the present application can automatically realize the fault diagnosis of the electromagnetic reversing valve according to the input current change curve and output voltage change curve of the valve control unit and the valve core signal output state of the electromagnetic reversing valve by setting a current detection unit, a voltage detection unit, a generation subunit and a fault diagnosis subunit, so as to timely discover the electromagnetic reversing valve fault and avoid safety hazards. And it can automatically diagnose which kind of fault the electromagnetic reversing valve has, which is more time-saving and labor-saving than manually troubleshooting the cause of the fault. The aging value of the electromagnetic reversing valve is determined according to the degree of valve core hysteresis to correct the preset operation and maintenance cycle, and output a preventive maintenance reminder signal or a replacement warning signal at a set time before reaching the corrected operation and maintenance cycle, so as to prevent the failure of the hydraulic system or the action execution component from erroneously causing equipment failure or even causing personnel danger due to the failure of the electromagnetic reversing valve. If it is detected that the unused time of the electromagnetic reversing valve exceeds the preset low-frequency test cycle, the electromagnetic reversing valve is controlled to work in a non-working state, which can avoid the response hysteresis of the electromagnetic reversing valve due to long-term non-use.

[0114] An embodiment of the present application also proposes a readable storage medium, on which one or more computer programs are stored. The one or more computer programs include instructions. When the program or instruction is executed by a host computer or a conversion unit, the host computer or the conversion unit can execute each process of any of the above-mentioned electromagnetic reversing valve fault diagnosis method embodiments.

[0115] The readable storage medium of the embodiment of the present application can automatically diagnose the fault of the electromagnetic reversing valve according to the input current change curve and output voltage change curve of the valve control unit and the valve core signal output state of the electromagnetic reversing valve by setting a current detection unit, a voltage detection unit, a generation subunit and a fault diagnosis subunit, so as to timely discover the fault of the electromagnetic reversing valve and avoid safety hazards. And it can automatically diagnose which kind of fault the electromagnetic reversing valve has, which is more time-saving and labor-saving than manually troubleshooting the cause of the fault. The aging value of the electromagnetic reversing valve is determined according to the degree of valve core hysteresis to correct the preset operation and maintenance cycle, and output a preventive maintenance reminder signal or a replacement warning signal at a set time before reaching the corrected operation and maintenance cycle, so as to prevent the failure of the hydraulic system or the action execution component from causing an error due to the failure of the electromagnetic reversing valve, causing equipment failure or even causing personnel danger. If it is detected that the unused time of the electromagnetic reversing valve exceeds the preset low-frequency test cycle, the electromagnetic reversing valve is controlled to work in a non-working state, which can avoid the response hysteresis of the electromagnetic reversing valve due to long-term non-use.

[0116] The systems, devices, modules or units described in the above embodiments may be implemented by computer chips or entities, or by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0117] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0118] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0119] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0120] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0121] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0122] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0123] Memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0124] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules 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 technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined in this article, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0125] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0126] The present application may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The present application may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules may be located in local and remote computer storage media, including storage devices.

[0127] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0128] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A fault diagnosis method for an electromagnetic reversing valve, characterized in that: include: Obtaining an input current variation curve and an output voltage variation curve of a valve control unit; Get the valve core signal output status of the electromagnetic reversing valve; The electromagnetic reversing valve is diagnosed for faults according to the input current variation curve, the output voltage variation curve and the valve core signal output state.

2. The fault diagnosis method according to claim 1, characterized in that: The method of performing fault diagnosis on the electromagnetic reversing valve according to the input current variation curve, the output voltage variation curve and the valve core signal output state includes: Obtaining a standard current change curve, a standard voltage change curve and a standard valve core signal output state when the electromagnetic reversing valve is working normally; If the input current variation curve, the output voltage variation curve and the valve core signal output state are respectively consistent with the standard current variation curve, the standard voltage variation curve and the standard valve core signal output state, it is determined that the electromagnetic reversing valve is normal; If at least one of the input current change curve, the output voltage change curve and the valve core signal output state is inconsistent with the standard current change curve, the standard voltage change curve and the standard valve core signal output state, it is determined that the electromagnetic reversing valve is faulty.

3. The fault diagnosis method according to claim 2, characterized in that: After determining that the electromagnetic reversing valve is normal, the method further includes: Continuously outputting a valve control signal to the valve control unit to control the electromagnetic reversing valve to perform the next action; After determining that the electromagnetic reversing valve is faulty, the method further includes: The valve control signal is stopped from being output to the valve control unit, and an alarm signal is output.

4. The fault diagnosis method according to claim 2, characterized in that: The determining that the electromagnetic reversing valve is faulty includes: 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 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 reversing valve has a valve core stuck fault.

5. The fault diagnosis method according to claim 2, characterized in that: The determining that the electromagnetic reversing valve is faulty includes: 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 be consistent with the preset voltage value in the standard voltage change curve is the preset response time, then it is determined that the electromagnetic reversing valve has a coil burnt out and a short circuit fault.

6. The fault diagnosis method according to claim 2, characterized in that: The determining that the electromagnetic reversing valve is faulty 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, it is determined that the solenoid reversing valve has a coil burnout and short circuit fault.

7. The fault diagnosis method according to claim 2, characterized in that: The determining that the electromagnetic reversing valve is faulty includes: 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 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 the preset response time, the valve core movement cannot be stopped 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 failure.

8. The fault diagnosis method according to claim 2, characterized in that: The determining that the electromagnetic reversing valve is faulty 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 for the valve core action 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, then it is determined that the electromagnetic reversing valve has a valve core hysteresis fault.

9. The fault diagnosis method according to claim 8, characterized in that: After determining that the solenoid reversing valve has a valve core hysteresis fault, the method further includes: Determine the aging value of the electromagnetic reversing valve according to 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; Performing weighted calculation on the aging value and the preset operation and maintenance cycle to obtain a revised operation and maintenance cycle; According to the revised operation and maintenance cycle, a maintenance reminder signal or a replacement warning signal is output at a set time before reaching the revised operation and maintenance cycle.

10. The fault diagnosis method according to claim 1, characterized in that: Also includes: When it is detected that the electromagnetic reversing valve has not been used for a period exceeding a preset low-frequency test period, a valve control signal is output to the valve control unit corresponding to the electromagnetic reversing valve in a non-working state.

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