A method for precisely controlling the magnetic force of a piling machine electromagnet

Abstract

The application provides a piling machine electromagnet magnetic force precise control method, a thyristor voltage regulation control loop is arranged in an electromagnet control cabinet of a piling machine, the method comprises the following steps: a direct current speed regulation device control loop is arranged in the piling machine; the direct current speed regulation device control loop is provided with the armature loop; communication is carried out through the direct current speed regulation device control loop, parameter data of the piling machine processing steel plates is received in real time, and the voltage output of the armature loop is dynamically adjusted; and the electrical interlocking and automatic switching of the thyristor voltage regulation control loop and the direct current speed regulation device control loop are controlled through PLC. The application solves the problem that the prior art lacks an electromagnet control method covering magnetic force precise control, adapting to multiple specifications of steel plates and having high reliability.

Description

Technical Field

[0001] This invention relates to the field of electromagnet control technology, and in particular to a method for precise control of the magnetic force of an electromagnet in a pallet stacking machine. Background Technology

[0002] In the steel production process, heat treatment is one of the key steps to improve the performance of steel plates. With the continuous growth in market demand for heat-treated steel plates, the stacking machines in the production line need to handle more frequent and diverse steel plate lifting tasks. These stacking machines typically need to handle steel plates with a wide range of thicknesses and lengths and widths. In particular, the proportion of thinner steel plates handled has shown a significant upward trend in recent years, which places higher demands on the precision and adaptability of the lifting equipment.

[0003] Currently, palletizing machines in this field generally employ electromagnet control systems based on programmable logic controllers (PLCs), using thyristor voltage regulation technology to adjust the electromagnet's magnetic force. A typical control scheme involves coarsely adjusting the output voltage using an analog potentiometer, thereby causing the electromagnet to generate a limited number of discrete magnetic force levels. This traditional control method has gradually revealed many inherent flaws in actual high-volume, multi-specification production environments: First, the granularity of magnetic force adjustment is too coarse, making it impossible to achieve fine, stepless adjustment. When processing large areas of thin steel plates, the fixed high-level magnetic force can easily attract multiple steel plates simultaneously, leading to batch confusion, incorrect material labeling, and serious risks of falling and safety hazards. On the other hand, manually switching to a lower level often results in the steel plates slipping due to insufficient magnetic force.

[0004] Secondly, the operation process is cumbersome and lacks automation. When faced with steel plates of different specifications, operators must frequently adjust the magnetic force setting manually and repeatedly test the physical gap between the electromagnet and the stack of steel plates to find a reliable adhesion point. This trial-and-error process, heavily reliant on manual experience, severely slows down the work pace, resulting in overall low efficiency.

[0005] Furthermore, the bottleneck problem of processing capacity is becoming increasingly prominent. Due to the limitations of adjustment precision and operating efficiency mentioned above, there is a clear upper limit to the number of thin steel plates that the stacking machine can safely lift per unit time. Its lifting cycle can no longer match the potential heating capacity of the subsequent heat treatment furnace, thus becoming a key bottleneck restricting the capacity improvement of the entire production line.

[0006] Furthermore, the existing discrete gear control mode is difficult to flexibly adapt to the complex and diverse specifications of steel plates, resulting in a lack of necessary flexibility in hoisting operations. This not only increases the labor intensity and mental stress of operators, but also generates significant mechanical and electrical noise during frequent equipment starts and stops and gear switching, causing noise pollution in the production environment. Summary of the Invention

[0007] This application provides a method for precise control of the magnetic force of an electromagnet in a pallet stacking machine, to solve the problem that the existing technology lacks an electromagnet control method that covers precise magnetic force control, adapts to multiple specifications of steel plates, and has high reliability.

[0008] The electromagnet control cabinet of the pallet stacker has a thyristor voltage regulation control circuit, and the method includes: A DC speed control circuit is provided in the stacking machine; the DC speed control circuit includes the armature circuit. The DC speed control device communicates with the control circuit to receive parameter data of the steel plates processed by the stacking machine in real time and dynamically adjust the voltage output of the armature circuit. The PLC controls the electrical interlocking and automatic switching of the thyristor voltage regulation control circuit and the DC speed control device control circuit.

[0009] In some embodiments, the output terminal of the armature circuit in the control circuit of the DC speed control device is connected to an electromagnet coil; The control circuit of the DC speed control device is configured to continuously control the magnetic force of the electromagnet coil by adjusting the voltage of the armature circuit.

[0010] In some embodiments, the control circuit of the DC speed control device also includes an excitation circuit; The control circuit of the DC speed regulator is also configured to set the output of the excitation circuit to zero.

[0011] In some embodiments, a voltage-specification mapping model is pre-set in the control loop of the DC speed controller; the communication via the control loop of the DC speed controller includes: The DC speed control device control circuit communicates with the PLC through the PROFIBUS-DP network to receive parameter data of the steel plates processed by the stacking machine; The voltage output of the armature circuit is dynamically adjusted using the voltage-specification mapping model.

[0012] In some embodiments, the parameter data includes steel plate thickness specifications, steel plate width specifications, and steel plate length specifications.

[0013] In some embodiments, the DC speed control device control circuit operates in a continuously adjustable armature circuit voltage mode of 0-440V; During the operation of the DC speed control device control circuit, the output of the excitation circuit remains at zero.

[0014] In some implementations, the pre-set voltage-specification mapping model is established based on field test data of the palletizing machine, which includes steel plate thickness of 6-150mm, steel plate length of 3-24m, and steel plate width of 1.5-4.1m.

[0015] In some implementations, the PLC is further configured to: The operating status of the DC speed control device control circuit is monitored in real time, and the circuit is automatically switched to the thyristor voltage regulation control circuit when an abnormality occurs in the DC speed control device control circuit. During the switching process between the DC speed control device control circuit and the thyristor voltage regulation control circuit, the magnetic force of the electromagnet coil is maintained at no less than 85% of the rated value.

[0016] In some implementations, the operational anomaly includes circuit failure, voltage fluctuations exceeding ±10%, and / or three failed startup attempts.

[0017] In some embodiments, the DC speed control device control loop also includes an adaptive filter circuit configured to suppress voltage ripple in the armature circuit.

[0018] As described above, this application provides a method for precise magnetic force control of an electromagnet in a pallet stacking machine. The electromagnet control cabinet of the pallet stacking machine has a thyristor voltage regulation control circuit. The method includes setting a DC speed regulation device control circuit in the pallet stacking machine; the DC speed regulation device control circuit includes the armature circuit; communication is achieved through the DC speed regulation device control circuit to receive parameter data of the steel plates processed by the pallet stacking machine in real time and dynamically adjust the voltage output of the armature circuit; the electrical interlocking and automatic switching of the thyristor voltage regulation control circuit and the DC speed regulation device control circuit are controlled by a PLC. This application solves the problem of the lack of an existing electromagnet control method that covers precise magnetic force control, adapts to multiple specifications of steel plates, and has high reliability. Attached Figure Description

[0019] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating a method for precise control of the magnetic force of an electromagnet in a pallet stacking machine, as described in this application. Figure 2 This is a hardware schematic diagram of a method for precise control of the magnetic force of an electromagnet in a stacking machine according to this application. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0023] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0024] See Figure 1 as well as Figure 2 As can be seen, this embodiment provides a method for precise control of the magnetic force of an electromagnet in a pallet stacking machine. The electromagnet control cabinet of the pallet stacking machine has a thyristor voltage regulation control circuit, and the method includes: S1, A DC speed control circuit is provided in the stacking machine; the DC speed control circuit includes the armature circuit.

[0025] Specifically, in this embodiment, a new DC speed control device control circuit is added. The output terminal of the armature circuit in the DC speed control device control circuit is connected to the electromagnet coil. The DC speed control device control circuit also has an excitation circuit. The DC speed control device control circuit continuously controls the magnetic force of the electromagnet coil by adjusting the voltage of the armature circuit, and sets the output of the excitation circuit to zero.

[0026] The DC speed control device control circuit operates in a continuously adjustable armature circuit voltage mode of 0-440V, with an output voltage accuracy better than ±0.5%; during the operation of the DC speed control device control circuit, the output of the excitation circuit remains at zero.

[0027] The method further includes: S2 communicates with the DC speed control device control circuit to receive parameter data of the steel plate being processed by the stacking machine in real time, and dynamically adjusts the voltage output of the armature circuit.

[0028] Specifically, in this embodiment, the DC speed control device control circuit is pre-set with a voltage-specification mapping model. The DC speed control device control circuit is also used to communicate with the PLC through the PROFIBUS-DP network to receive parameter data of the steel plate being processed by the stacking machine, and to dynamically adjust the voltage output of the armature circuit through the voltage-specification mapping model.

[0029] The parameter data includes steel plate thickness specifications, steel plate width specifications, and steel plate length specifications.

[0030] The pre-set voltage-specification mapping model is established based on the field test data of the stacking machine. The field test data includes steel plate thickness of 6-150mm, steel plate length of 3-24m, and steel plate width of 1.5-4.1m.

[0031] The method further includes: S3, the PLC controls the electrical interlocking and automatic switching of the thyristor voltage regulation control circuit and the DC speed regulation device control circuit.

[0032] Specifically, in this embodiment, the PLC monitors the operating status of the DC speed control device control circuit in real time, and automatically switches to the thyristor voltage regulation control circuit when the DC speed control device control circuit malfunctions; during the switching process between the DC speed control device control circuit and the thyristor voltage regulation control circuit, the magnetic force of the electromagnet coil remains no less than 85% of the rated value.

[0033] The operational anomalies include circuit faults, voltage fluctuations exceeding ±10%, and / or three failed startups.

[0034] Furthermore, in some embodiments, the DC speed control device control circuit also includes an adaptive filter circuit configured to suppress voltage ripple in the armature circuit.

[0035] Specifically, in this embodiment, the adaptive filter circuit suppresses armature voltage ripple to ensure stable magnetic output.

[0036] For example: This embodiment adds a DC speed control device (such as the Siemens 6RA80 series) to the existing electromagnet control cabinet, which is connected to the electromagnet coil via a circuit breaker, contactor, and high-energy varistor. The armature circuit output of the DC speed control device is directly connected to the electromagnet coil, providing an adjustable DC power supply to the electromagnet; the excitation circuit output of the device is set to zero and not connected to any load. The DC speed control device is connected to the PROFIBUS-DP network via a CBP2 communication board, acting as a slave station to receive PLC control. The PLC reads MES data such as the thickness, width, and length of the steel plate, calculates the target armature voltage based on a preset voltage-specification mapping model using a PID algorithm, and writes it to the DC speed control device in real time via the PPO process data object. The device performs voltage / current closed-loop control internally, outputting the corresponding armature voltage to achieve precise magnetic force adjustment.

[0037] This embodiment retains the original thyristor control circuit and uses a PLC to control a DC contactor to achieve electrical interlocking between the main and backup circuits. During normal operation, the DC speed controller runs while the thyristor circuit is in standby mode. When the PLC detects a fault in the DC speed controller, an output voltage fluctuation exceeding ±10%, or three failed starts, it automatically disconnects the DC speed controller output contactor and closes the thyristor circuit contactor. During the switching process, the electromagnet's magnetic force remains at no less than 85% of its rated value to ensure lifting safety.

[0038] The implementation steps are as follows: 1. Establish an electromagnet performance testing platform on site, conduct magnetization and demagnetization tests on steel plates of different specifications, establish a voltage-specification mapping database, and determine the optimal armature voltage range for each specification of steel plate; 2. Install three DC speed control cabinets next to the original electromagnet control cabinet in Electrical Room #1, and complete hard-wired connections and PROFIBUS-DP communication debugging; 3. Taking the No. 1 stacking machine as a pilot, configure PLC input and output signals, including DC speed control device circuit breaker closing feedback, thyristor circuit breaker closing feedback, device start feedback, etc., to realize PLC monitoring and switching control of dual circuits; 4. Verify the accuracy of MES data transmission to the PLC and the data communication between the PLC and the DC speed control device, and test the actual hoisting effect. For example, when handling a 12mm thick Q345 steel plate, the PLC automatically calls parameter group P05, sets the initial armature voltage to 325V, and performs ±15V dynamic compensation based on the flatness of the steel plate surface; 5. Verify the manual, remote semi-automatic, and fully automatic operation modes and their interlocking functions to ensure the system is flexible and reliable.

[0039] This embodiment has the following advantages: The original thyristor voltage regulation control is replaced with DC speed regulation device control. The adjustable DC voltage output from the armature circuit of the device is used to directly power the electromagnet coil, so as to achieve continuous and precise adjustment of the magnetic force. The excitation circuit output of the DC speed control device is kept at zero, and only the armature circuit is used as the electromagnet power supply, which simplifies the control structure. The DC speed control device uses armature voltage / current closed-loop control, and the output voltage is continuously adjustable from 0-440V. The magnetic output is precisely matched with the steel plate specifications. The system receives MES data such as steel plate thickness, width, and length from the PLC in real time via the PROFIBUS-DP network, and automatically calculates and outputs the optimal armature voltage based on the preset voltage-specification mapping model. The original thyristor control circuit is retained as a backup system. The PLC monitors the operating status of the DC speed control device in real time and automatically switches to the backup circuit in case of abnormality to ensure continuous and reliable operation of the system. It supports three operating modes: manual, remote semi-automatic, and fully automatic, with interlocking switching between modes to adapt to different working conditions.

[0040] Field tests showed that the success rate of single-lifting of thin plates under 16mm increased from 68% to 93%, the average lifting cycle was shortened from 5.2 minutes to 3.1 minutes, and the magnetic overshoot was reduced from ±25% to within ±5%, significantly improving the efficiency and safety of the palletizer.

[0041] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the discussion in some embodiments is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the contents of this disclosure, thereby enabling those skilled in the art to better utilize the embodiments.

Claims

1. A method for precise control of the magnetic force of an electromagnet in a pallet stacking machine, characterized in that, The electromagnet control cabinet of the pallet stacker has a thyristor voltage regulation control circuit, and the method includes: A DC speed control circuit is provided in the stacking machine; the DC speed control circuit includes the armature circuit. The DC speed control device communicates with the control circuit to receive parameter data of the steel plates processed by the stacking machine in real time and dynamically adjust the voltage output of the armature circuit. The PLC controls the electrical interlocking and automatic switching of the thyristor voltage regulation control circuit and the DC speed control device control circuit.

2. The method for precise control of the magnetic force of an electromagnet in a pallet stacking machine according to claim 1, characterized in that, The output terminal of the armature circuit in the control circuit of the DC speed regulating device is connected to an electromagnet coil. The control circuit of the DC speed control device is configured to continuously control the magnetic force of the electromagnet coil by adjusting the voltage of the armature circuit.

3. The method for precise control of the magnetic force of an electromagnet in a pallet stacking machine according to claim 2, characterized in that, The control circuit of the DC speed regulating device also includes an excitation circuit; The control circuit of the DC speed regulator is also configured to set the output of the excitation circuit to zero.

4. The method for precise control of the magnetic force of an electromagnet in a pallet stacking machine according to claim 1, characterized in that, The DC speed control device control circuit has a pre-set voltage-specification mapping model; the communication through the DC speed control device control circuit includes: The DC speed control device control circuit communicates with the PLC through the PROFIBUS-DP network to receive parameter data of the steel plates processed by the stacking machine; The voltage output of the armature circuit is dynamically adjusted using the voltage-specification mapping model.

5. The method for precise control of the magnetic force of an electromagnet in a pallet stacking machine according to claim 1, characterized in that, The parameter data includes steel plate thickness specifications, steel plate width specifications, and steel plate length specifications.

6. The method for precise control of the magnetic force of an electromagnet in a pallet stacking machine according to claim 3, characterized in that, The DC speed control device control circuit operates in a continuously adjustable armature circuit voltage mode of 0-440V. During the operation of the DC speed control device control circuit, the output of the excitation circuit remains at zero.

7. The method for precise control of the magnetic force of an electromagnet in a pallet stacking machine according to claim 4, characterized in that, The pre-set voltage-specification mapping model is established based on the field test data of the stacking machine. The field test data includes steel plate thickness of 6-150mm, steel plate length of 3-24m, and steel plate width of 1.5-4.1m.

8. The method for precise control of the magnetic force of an electromagnet in a pallet stacking machine according to claim 1, characterized in that, The PLC is also configured to: The operating status of the DC speed control device control circuit is monitored in real time, and the circuit is automatically switched to the thyristor voltage regulation control circuit when an abnormality occurs in the DC speed control device control circuit. During the switching process between the DC speed control device control circuit and the thyristor voltage regulation control circuit, the magnetic force of the electromagnet coil is maintained at no less than 85% of the rated value.

9. A method for precise control of the magnetic force of an electromagnet in a pallet stacking machine according to claim 8, characterized in that, The operational anomalies include circuit failures, voltage fluctuations exceeding ±10%, and / or three failed startups.

10. A method for precise control of the magnetic force of an electromagnet in a pallet stacking machine according to claim 1, characterized in that, The control circuit of the DC speed control device also includes an adaptive filter circuit, which is configured to suppress voltage ripple in the armature circuit.

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