Electromagnetic chuck control method and apparatus

Abstract

The application discloses an electromagnetic chuck control method and device, the method comprises the following steps: acquiring the voltage U1 of an external power supply; comparing the voltage U1 of the external power supply with a standard set voltage U2, if the ratio A is within a preset range, outputting a set rectifier bridge angle, if the ratio A is outside the preset range, adjusting the rectifier bridge control angle according to A; acquiring the working voltage U3 of the electromagnetic chuck according to the rectifier bridge control angle; comparing the working voltage U3 of the electromagnetic chuck with the required voltage U4 of the electromagnetic chuck, if the ratio B is within a preset range, outputting a set rectifier bridge angle, if the ratio B is outside the preset range, adjusting the rectifier bridge control angle according to B; and the rectifier bridge angle controls the electromagnetic chuck to work. The application effectively guarantees the stability of the electromagnetic chuck control through two-stage comparison.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of suction cup, in particular to a control method and device of electromagnetic suction cup. BACKGROUND

[0002] In recent years, with the increasing pressure of environmental protection, especially the reuse of waste steel and other resources, the demand for engineering machinery for material handling, unloading and other functions is also increasing.

[0003] At present, the market usually adopts excavators with lotus claw and shell bucket to carry out material handling and unloading, but each tool has certain limitations on the shape and volume of the grabbed material. It is not suitable for grabbing bulk materials at the bottom of the carriage or ship cabin or cylindrical materials. Instead, the electromagnetic suction cup meets the demand for cleaning bulk materials at the bottom of the carriage or ship cabin and processing operations of steel plates, scrap steel and other materials.

[0004] (1) At present, the main material grabbing machine of the electromagnetic suction cup on the market is modified through excavators. There are three main modification schemes: the first is to install an independent generator set outside, the generator set is connected with the suction cup control cabinet, and the control cabinet is connected with the electromagnetic suction cup; the second is to convert a generator on the engine, the generator is connected with the suction cup control cabinet, and the control cabinet is connected with the electromagnetic suction cup; the third is to drive the hydraulic motor through the hydraulic pressure, and the hydraulic motor drives the generator to generate electricity, the generator is connected with the control cabinet, and the control cabinet is connected with the electromagnetic suction cup. The above three modification schemes can realize the work of the electromagnetic suction cup. The three technologies of external generator set, engine driven generator and hydraulic motor driven generator have inconsistent power supply voltage, the suction cup control system cannot be universal, and each needs to be equipped with a separate control system. When the suction cup works, the voltage output from the control cabinet to the suction cup is unstable.

[0005] (2) The previous patent technology CN201420187131.0 provides a ship dismantling steel suction machine, which generates electricity through the suction cup motor, supplies direct current to the electromagnetic steel suction disc after rectification by the control cabinet, and installs an electromagnetic steel suction disc switch in the cab to control the suction and discharge of the electromagnetic steel suction disc. The control system of this scheme is simple, there is no electromagnetic suction disc magnetic force adjusting device, the magnetic force size is not adjustable; there is no instrument to monitor the working state of the electromagnetic suction cup in real time, and there is a lack of safety protection mechanism. There is also the phenomenon that the voltage output from the control cabinet to the suction cup is unstable when the suction cup works. SUMMARY

[0006] The purpose of the present application is to provide a control method and device of electromagnetic suction cup, to solve the problem that the power supply voltage of different power supplies in the prior art is different, resulting in unstable voltage output to the suction cup.

[0007] To achieve the above purpose, the technical scheme of the present application is as follows:

[0008] The application discloses an electromagnetic chuck control method, comprising:

[0009] acquiring a voltage U1 of an external power supply;

[0010] comparing the voltage U1 of the external power supply with a standard set voltage U2, if a ratio A is within a preset range, outputting a set rectifier bridge angle, if the ratio A is outside the preset range, adjusting the rectifier bridge control angle according to A;

[0011] acquiring a working voltage U3 of the electromagnetic chuck according to the rectifier bridge control angle;

[0012] comparing the working voltage U3 of the electromagnetic chuck with a required voltage U4 of the electromagnetic chuck, if a ratio B is within a preset range, outputting the rectifier bridge angle, if the ratio B is outside the preset range, adjusting the rectifier bridge control angle according to B;

[0013] controlling the electromagnetic chuck to work according to the rectifier bridge angle.

[0014] Further, the external power supply comprises a hydraulic motor generator, a generator set and commercial power.

[0015] Further, if the external power supply is the hydraulic motor generator, further comprising the following steps:

[0016] acquiring a frequency value f1 of the hydraulic motor;

[0017] comparing the acquired frequency value f1 of the hydraulic motor with a required frequency value f2, if a ratio n is within a preset range, outputting a set electromagnetic valve current, if the ratio n is outside the preset range, reacquiring the electromagnetic valve current according to n, and adjusting the electromagnetic valve of the hydraulic motor according to the electromagnetic valve current to adjust the frequency value f1 of the hydraulic motor.

[0018] Further, further comprising:

[0019] detecting a connection state of the external power supply, an electric quantity of an energy storage capacitor and a working state of the electromagnetic chuck;

[0020] in response to that the external power supply is in the connection state and the electromagnetic chuck does not work, controlling the energy storage capacitor to charge;

[0021] in response to that the external power supply is in the connection state, the electromagnetic chuck works and the electric quantity of the energy storage capacitor is lower than a set value C, controlling the energy storage capacitor to charge;

[0022] in response to that the external power supply is in the disconnection state and the electromagnetic chuck works, controlling the energy storage capacitor to discharge to make the electromagnetic chuck work.

[0023] Further, when the external power supply is in the disconnection state and the electromagnetic chuck works, further comprising the following steps:

[0024] acquire the real-time power of the energy storage capacitor;

[0025] send an alarm instruction in response to the real-time power of the energy storage capacitor being lower than a set value D.

[0026] The application further discloses an electromagnetic chuck control device, which comprises:

[0027] The AC contactor is connected with a plurality of external power sources, and is also connected with a controller.

[0028] The AC contactor is connected with a rectifier bridge, the rectifier bridge is connected with an electromagnetic chuck, and the rectifier bridge is connected with the controller.

[0029] The controller is used for controlling the operation of the electromagnetic chuck or adjusting the angle of the rectifier bridge according to the external power source voltage U1 and the standard set voltage U2, and is used for controlling the operation of the electromagnetic chuck or adjusting the angle of the rectifier bridge according to the working voltage U3 of the electromagnetic chuck and the required voltage U4 of the electromagnetic chuck.

[0030] Further, the external power sources comprise a hydraulic motor generator, a generator set and a commercial power supply.

[0031] The hydraulic motor generator, the generator set and the commercial power supply are connected with a U-phase transformer, a V-phase transformer and a W-phase transformer respectively through the AC contactor, and the U-phase transformer, the V-phase transformer and the W-phase transformer are connected with a comparator and a controller between each other.

[0032] Further, the controller is connected with a solenoid valve used for controlling the hydraulic motor generator.

[0033] Further, an inverter is further connected between the rectifier bridge and the AC contactor, the inverter is connected with a storage capacitor through a control module, and the control module is connected with the controller.

[0034] The controller is used for controlling the charging and discharging of the storage capacitor according to the connection state of the external power source, the power of the storage capacitor and the working state of the electromagnetic chuck.

[0035] Further, the controller is connected with an operation panel, and the operation panel is connected with an instrument.

[0036] According to the above technical solution, the embodiments of the application have at least the following effects:

[0037] The input voltage of the external power supply is compared with the standard set voltage to output the set rectifier bridge angle or adjust the rectifier bridge control angle, the actual working voltage of the suction cup is obtained according to the rectifier bridge control angle, the actual working voltage is compared with the required voltage, the rectifier bridge control angle is adjusted or the rectifier bridge angle is output according to the comparison result, and then the electromagnetic suction cup is controlled to work, when the input voltage and the standard voltage exist difference, the stability of the output voltage is ensured through two-stage comparison, and the working stability of the electromagnetic suction cup is effectively ensured. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The connection block diagram of the control device in the embodiment of the application is shown in the figure;

[0039] Figure 2 The flow chart of the control method in the embodiment of the application is shown in the figure;

[0040] Figure 3 The flow chart of the control method of the hydraulic motor frequency adjustment in the embodiment of the application is shown in the figure;

[0041] Figure 4 The flow chart of the control method of the inverter charging and discharging in the embodiment of the application is shown in the figure

[0042] Among them: 1, AC contactor; 2, U-phase transformer; 3, V-phase transformer; 4, W-phase transformer; 5, comparator 1; 6, comparator 2; 7, comparator 3; 8, SCR rectifier bridge; 9, electromagnetic suction cup; 10, control panel; 11, controller; 12, suction cup operation switch; 13, mode switch; 14, electromagnetic valve; 15, instrument; 16, hydraulic motor generator; 17, generator set; 18, mains; 19, inverter; 20, control module; 21, energy storage capacitor. DETAILED DESCRIPTION

[0043] In order to make the technical means, creative features, purposes and effects realized by the application easy to understand, the application is further described below in combination with specific embodiments.

[0044] The application discloses an electromagnetic suction cup control device. The device comprises an AC contactor 1, a plurality of external power supplies are connected to the AC contactor 1, and a controller 11 is also connected to the AC contactor 1; the AC contactor 1 is connected with a rectifier bridge, the rectifier bridge is connected with an electromagnetic suction cup 9, and the rectifier bridge is connected with the controller 11; the controller is used for controlling the electromagnetic suction cup to work or adjusting the rectifier bridge angle according to the voltage U1 of the external power supply and the standard set voltage U2, and is used for controlling the electromagnetic suction cup to work or adjusting the rectifier bridge angle according to the working voltage U3 of the electromagnetic suction cup and the required voltage U4 of the electromagnetic suction cup.

[0045] Specifically, the external power supply includes: external three-phase alternating current power supply U, V, W (the market external power supply generally has three kinds, hydraulic motor generator 16, generator set 17 and mains 18) is connected to the alternating current contactor 1, the alternating current contactor 1 and the U-phase transformer 2, the V-phase transformer 3 and the W-phase transformer 4 are electrically connected with the alternating current contactor 1, and the U-phase transformer 2 and the V-phase transformer 3 are electrically connected with the comparator one 5 after the transformer; the V-phase transformer 3 and the W-phase transformer 4 are electrically connected with the comparator two 6 after the transformer; the U-phase transformer 2 and the W-phase transformer 4 are electrically connected with the comparator three 7 after the transformer. The comparator 1, the comparator 2 and the comparator 3 are connected with the control panel 10 respectively. The controller 11 is connected on the control panel 10, and the suction cup operation switch 12, the mode switch 13, the electromagnetic valve 14 and the instrument 15 are connected on the controller 11.

[0046] At the same time, the alternating current contactor 1 is electrically connected with the inverter 19, and the inverter 19, the control module 20 and the energy storage capacitor 21 are sequentially electrically connected. The control module is connected through the control panel 10 and the controller 11.

[0047] The external three-phase alternating current power supply U, V, W is electrically connected with the SCR rectifier bridge 8, the SCR rectifier bridge 8 is electrically connected with the control panel 10, and the output voltage of the SCR rectifier bridge 8 is electrically connected with the electromagnetic suction cup 9, and the output voltage is fed back to the control panel 10.

[0048] In the device, the controller 11 can control according to the comparison result of the external power supply voltage U1 and the standard set voltage U2, when the comparison result is in the set range, the electromagnetic suction cup 9 is controlled to work, and when the comparison result is out of the set range, the angle of the SCR rectifier bridge 8 is adjusted. After adjusting the angle of the SCR rectifier bridge 8, the working voltage U3 of the electromagnetic suction cup is obtained, and U3 and the required voltage U4 of the electromagnetic suction cup are compared, and the electromagnetic suction cup is controlled to work or the angle of the rectifier bridge is adjusted again according to the comparison result.

[0049] In the device, through the design of the inverter 19, the control module 20 and the energy storage capacitor 21, charging and discharging can be realized. When the external power supply is the hydraulic motor generator 16 and the generator set 17, the controller controls the charging and discharging of the energy storage capacitor according to the state of the external power supply, the electric quantity of the energy storage capacitor 21 and the working state of the electromagnetic suction cup 9, on the one hand, to prevent the waste of electric quantity caused by the working of the external power supply, and on the other hand, to ensure the stable working of the electromagnetic suction cup 9.

[0050] The application also discloses a method for controlling the electromagnetic chuck, which can be realized based on the device in the above embodiment, and the method comprises the following steps of: acquiring the voltage U1 of an external power supply; comparing the voltage U1 of the external power supply with a standard set voltage U2, if the ratio A is within a preset range, outputting a set rectifier bridge angle, and if the ratio A is out of the preset range, adjusting the rectifier bridge control angle according to the ratio A; acquiring the working voltage U3 of the chuck according to the rectifier bridge control angle; comparing the working voltage U3 of the chuck with the required voltage U4 of the chuck, if the ratio B is within a preset range, outputting a set rectifier bridge angle, and if the ratio B is out of the preset range, adjusting the rectifier bridge control angle according to the ratio B; and controlling the electromagnetic chuck to work according to the rectifier bridge angle.

[0051] The application compares the input voltage of the external power supply with the standard set voltage to output a set rectifier bridge angle or adjust the rectifier bridge control angle, acquires the actual working voltage of the chuck according to the rectifier bridge control angle, compares the actual working voltage with the required voltage, adjusts the rectifier bridge control angle or outputs the rectifier bridge angle according to the comparison result, and then controls the electromagnetic chuck to work. When there is a difference between the input voltage and the standard voltage, the two-stage comparison ensures the stability of the output voltage and effectively ensures the stable working of the electromagnetic chuck.

[0052] Specifically, the method for controlling the electromagnetic chuck comprises the following steps.

[0053] Step 10: detecting the voltage U1 of the external input power supply.

[0054] In this step, the external input power supply can be a power supply provided by a hydraulic motor driving a generator to work, a power supply provided by an engine driving a generator to work, a power supply provided by a commercial power supply or a power supply provided by other power supply devices.

[0055] Step 20: comparing the voltage U1 of the external power supply with the standard set voltage U2, if the ratio A is within a preset range, outputting a set rectifier bridge angle, and if the ratio A is out of the preset range, adjusting the rectifier bridge control angle according to the ratio A.

[0056] In this step, the ratio A is preferably between 0.95 and 1.05. This design can make the difference between the voltage of the external power supply and the standard set voltage within a controllable range, so that the set rectifier bridge angle can still be outputted without affecting the stable working of the electromagnetic chuck. If the difference between the voltage of the external power supply and the standard set voltage affects the stable working of the electromagnetic chuck, the rectifier bridge control angle needs to be adjusted again to ensure the control effect on the electromagnetic chuck.

[0057] Step 30: acquiring the working voltage U3 of the chuck according to the rectifier bridge control angle. Different rectifier bridge control angles correspond to different working voltages, and the working voltage U3 of the chuck is acquired according to the rectifier bridge control angle.

[0058] Step 40, compare the working voltage U3 of the suction cup and the required voltage U4 of the suction cup, if the ratio B is within the preset range, output the set control angle of the rectifier bridge, if the ratio B is outside the preset range, adjust the rectifier bridge control angle according to B.

[0059] In this step, the ratio B is preferably between 0.95-1.05, which can make the difference between the actual working voltage U3 and the set required voltage U4 within the controllable range, and will not affect the suction cup when sucking the workpiece, and still can output the set rectifier bridge angle. If the difference between the actual working voltage U3 and the set required voltage U4 will affect the suction cup when sucking the workpiece, the rectifier bridge control angle needs to be adjusted, and after adjusting the angle, the step 30 is executed again to obtain a new working voltage U3, and then the newly obtained working voltage and the required voltage are compared. ±5% is acceptable.

[0060] Step 50, input voltage is different, adjust the control angle of the rectifier bridge, realize output stable voltage, control the electromagnetic suction cup to work.

[0061] In this step, the electromagnetic suction cup is controlled according to the rectifier bridge angle. If the voltage U1 of the external power supply and the standard set voltage U2 are within the preset range, the rectifier bridge angle is the initial set angle, and if they are not within the preset range, it is the rectifier bridge angle that meets the conditions after comparison and adjustment.

[0062] The method compares the actual input voltage U1 and the standard set voltage U2, compares the actual output working voltage U3 and the set required voltage U4, and adjusts the output working voltage through two closed loops. So that there is a stable output working voltage under any working condition, which ensures the stability of the suction operation.

[0063] When the external power supply is a hydraulic motor driving a generator, the frequency will be unstable. The present application provides a method that can realize stable frequency output:

[0064] Step 100, obtain the frequency value f1 of the hydraulic motor; in this step, the frequency value f1 of the hydraulic motor can be obtained through the controller;

[0065] Step 200, compare the input power frequency value f1 obtained with the working required frequency value f2, if the ratio n is within the preset range, output the set electromagnetic valve current, if the ratio n is outside the preset range, recalculate the current value according to n; for example: the current collected power frequency is 30HZ, the working required frequency is 50HZ, the current value at this time is 390mA, through the calculation n=50 / 30, recalculate the current value n*390, at this time the current value is adjusted to 650mA.

[0066] Step 300, adjust the electromagnetic valve of the hydraulic motor according to the current value to adjust the frequency value f1 of the input power supply

[0067] Step 400, the controller sends the current frequency value to the instrument through the CAN bus for real-time display.

[0068] When the external power supply is suddenly disconnected, the magnetic disc has no voltage, which can cause demagnetization, and if it is in the process of material suction, it will cause the safety hazard of material falling. Therefore, a device is needed to provide power supply after the external power supply disappears. When the external power supply is a generator set or a hydraulic motor generator, the machine operation will cause energy waste when not operating the material suction. At this time, the generated electricity needs to be stored, and the stored electric energy is used as an emergency situation. The charge and discharge control method is as follows Figure 4 As shown in the figure:

[0069] Step 60, detect the external power supply input, and detect the electric quantity of the energy storage capacitor and the working state of the electromagnetic chuck;

[0070] Step 70, when the external power supply is in the connected state, if the electromagnetic chuck is not in the working state, control the charging control module to charge. If the electromagnetic chuck is in the working state, it is judged whether the electric quantity of the energy storage capacitor is lower than the set value, if lower than the set value, inverse charging is carried out, if higher than the set value, no charging is carried out.

[0071] Step 80, when it is detected that the external power supply is suddenly disconnected, control the AC contactor to be disconnected, and at the same time, the energy storage capacitor is connected to the inverter to carry out inversion and power supply.

[0072] Step 90, display the electric quantity of the energy storage capacitor to the instrument, and carry out safety operation according to the electric quantity.

[0073] From the technical common sense, the application can be realized by other embodiments without departing from the spirit or essential characteristics thereof. Therefore, the above disclosed embodiments are only examples, and are not the only ones. All changes within the scope of the application or within the scope equivalent to the application are included in the application.

Claims

1. A method of controlling an electromagnetic chuck, characterized by, include: Obtain the voltage U1 of the external power supply; The voltage U1 of the external power supply is compared with the standard set voltage U2. If the ratio A is within the preset range, the set rectifier bridge angle is output. If the ratio A is outside the preset range, the rectifier bridge control angle is adjusted according to A. The operating voltage U3 of the electromagnetic chuck is obtained based on the control angle of the rectifier bridge. Compare the working voltage U3 of the electromagnetic chuck with the required voltage U4 of the electromagnetic chuck. If the ratio B is within the preset range, output the rectifier bridge angle. If the ratio B is outside the preset range, adjust the rectifier bridge control angle according to B. The operation of the electromagnetic chuck is controlled by the angle of the rectifier bridge.

2. The electromagnetic chuck control method of claim 1 wherein, The external power source includes hydraulic motor generators, generator sets, and mains power.

3. The electromagnetic chuck control method of claim 2 wherein, If the external power source is a hydraulic motor generator, the following steps are also included: Obtain the frequency value f1 of the hydraulic motor; The frequency value f1 of the hydraulic motor is compared with the required frequency value f2. If the ratio n is within the preset range, the set solenoid valve current is output. If the ratio n is outside the preset range, the solenoid valve current is re-acquired according to n, and the solenoid valve of the hydraulic motor is adjusted according to the solenoid valve current to adjust the frequency value f1 of the hydraulic motor.

4. The electromagnetic chuck control method of claim 1 wherein, Also includes: Detect the connection status of the external power supply, the charge of the energy storage capacitor, and the working status of the electromagnetic chuck; When an external power source is connected and the electromagnetic chuck is not working, the energy storage capacitor is charged. When the external power supply is connected, the electromagnetic chuck is working, and the charge of the energy storage capacitor is lower than the set value C, the energy storage capacitor is controlled to charge. In response to the external power supply being disconnected and the electromagnetic chuck being in operation, the energy storage capacitor is controlled to discharge so that the electromagnetic chuck can operate.

5. The electromagnetic chuck control method of claim 4 wherein, When the external power supply is off and the electromagnetic chuck is working, the following steps are also included: Obtain the real-time charge level of the energy storage capacitor; An alarm command is sent when the real-time charge of the energy storage capacitor is lower than the set value D.

6. An electromagnetic chuck control apparatus characterized by comprising: The electromagnetic chuck control method according to any one of claims 1-5 includes: An AC contactor, on which multiple external power supplies are connected, and a controller is also connected; The AC contactor is connected to the rectifier bridge, the rectifier bridge is connected to the electromagnetic chuck, and the rectifier bridge is connected to the controller; The controller is used to control the operation of the electromagnetic chuck or adjust the rectifier bridge angle according to the external power supply voltage U1 and the standard setting voltage U2, and to control the operation of the electromagnetic chuck or adjust the rectifier bridge angle according to the operating voltage U3 and the required voltage U4 of the electromagnetic chuck.

7. The electromagnetic chuck control apparatus of claim 6 wherein, The external power source includes hydraulic motor generators, generator sets, and mains power; The hydraulic motor generator, generator set, and mains power are connected to the U-phase transformer, V-phase transformer, and W-phase transformer respectively via AC contactors. The U-phase transformer, V-phase transformer, and W-phase transformer are connected to each other via comparators and controllers.

8. The electromagnetic chuck control apparatus of claim 7 wherein, The controller is connected to a solenoid valve for controlling the hydraulic motor generator.

9. The electromagnetic chuck control apparatus of claim 6 wherein, An inverter is also connected between the rectifier bridge and the AC contactor. The inverter is connected to the energy storage capacitor through a control module. The control module is connected to the controller through a control panel. The controller is used for controlling the charging and discharging of the energy storage capacitor according to the connection state of the external power supply, the electricity of the energy storage capacitor and the working state of the electromagnetic chuck.

10. The electromagnetic chuck control apparatus of claim 6 wherein, An operation panel is connected to the controller, and an instrument is connected to the operation panel.

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