Contactless electronic switch control system of crane

Abstract

According to the contactless electronic switch control system for the crane, the main loop and the control loop are both connected with the electronic thyristor contactless switch and are controlled by the trigger control module, so that the control of the electronic thyristor contactless switch is realized, the phenomena of poor mechanical contact, electric arc burning loss, contact jamming or adhesion and the like are avoided, and the safety of the crane is improved. The electronic thyristor contactless switch drives the electromagnetic coil of the three-phase alternating-current motor to move, so that the possibility of accidents caused by burning loss of the coil is avoided, energy waste caused by long-term electrification of the coil is reduced, the response speed of the whole system is increased, and the control precision is improved. A control loop is an electronic trigger circuit, and all the control loops are low-voltage weak current (24V or 5V) which is lower than safe voltage, so that the safety of operators is ensured; according to the utility model, closed-loop control is realized while the response speed of the control system is accelerated, and the system is simple to operate, high in working efficiency, energy-saving and safe to operate.

Description

Technical Field

[0001] The utility model relates to a control system, in particular to a contactless electronic switch control system for a crane. Background Art

[0002] The working principle of metallurgical crane is mainly realized by electrically controlling the special motor for metallurgical lifting. The advantage is that it can give full play to the advantages of the special motor for metallurgical lifting (strong load-bearing capacity and reliable operation). Since the 1970s, my country's unified design of general-purpose gantry crane electronic control equipment is the XQR series. Since then, some improvements have been made, including the addition of air circuit breakers, the increase of phase-changing contactors in the operating mechanism, and the use of CJ20 series contactors. At the same time, it is also considered to add a coasting gear, the current starting principle, and the addition of a rotor contactor welding inspection link. However, the entire system has not deviated from the original overall design concept, and the product performance has not changed essentially. In addition, the number of electrical components has increased, the failure rate has also increased significantly, and maintenance is difficult. Subsequently, stator voltage regulation and speed control and variable frequency speed control were developed. These two speed control methods only improve the control accuracy, but have limitations and require the replacement of variable frequency motors. The working conditions of the variable frequency drive are relatively harsh and are not suitable for working in the harsh environment of the metallurgical industry. The failure rate is higher and it is not easy for front-line workers to repair. Summary of the Invention

[0003] In order to solve the above technical problems, the utility model is a contactless electronic switch control system for a crane, and its technical solution is as follows:

[0004] It includes a main circuit and a control circuit. The main circuit includes a three-phase power supply, a circuit breaker, a motor protector, a fast fuse, an electronic thyristor contactless switch and a three-phase AC motor connected in sequence. The motor protector is also connected to the trigger control module signal.

[0005] The control circuit is an electronic trigger circuit, which is given by the master command signal to the trigger control module;

[0006] The trigger control module gives the electronic thyristor contactless switch and brake control signals respectively to realize the start and stop operation of the three-phase AC motor or brake control;

[0007] Electronic thyristor contactless switches control the start and stop operations of the stator and rotor of three-phase AC motors.

[0008] Furthermore, a three-phase power supply is provided at the main power supply location for powering the equipment;

[0009] The circuit breaker is set at the main control circuit position to isolate the main circuit;

[0010] The motor protector is set in the main circuit position to monitor the motor operating status;

[0011] The fast fuse is set in the main circuit position for short circuit protection;

[0012] The electronic thyristor contactless switch is set on the electronic radiator and is used for forward and reverse control of the motor stator and rotor speed regulation;

[0013] Three-phase AC motor is used to control the operation of the crane;

[0014] Furthermore, the main circuit and the control circuit are both arranged on the linkage platform in the driver's cab.

[0015] The beneficial effects of the present invention are as follows: the present invention is a contactless electronic switch control system for a crane. The main circuit and the control circuit are both connected to the electronic thyristor contactless switch and controlled by a trigger control module, thereby realizing electronic thyristor contactless switch control and avoiding phenomena such as poor mechanical contact, arc burnout, and contact jamming or adhesion. The electronic thyristor contactless switch drives the electromagnetic coil of a three-phase AC motor to move, avoiding the possibility of accidents due to coil burnout, reducing energy waste caused by long-term power supply to the coil, and accelerating the response speed of the entire system and improving control accuracy. The control circuit is an electronic trigger circuit, all of which are low-voltage weak current (24V or 5V), which is lower than the safety voltage, ensuring the safety of the operator. The present invention realizes closed-loop control while accelerating the response speed of the control system. It is simple to operate, has high operating efficiency, saves energy, and is safe to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a working system diagram of the utility model;

[0017] Figure 2 This is the circuit diagram of the utility model;

[0018] Figure 3 This is the layout diagram of the utility model. DETAILED DESCRIPTION

[0019] The main circuit of the motor for metallurgical hoisting is replaced by an electronic thyristor contactless switch, controlled by a control module, achieving electronic contactless control. This avoids mechanical contact failure, arc burnout, contact sticking, or adhesion. The drive electromagnetic coil without mechanical contacts avoids the possibility of accidents caused by coil burnout and reduces energy waste caused by long-term coil power supply, resulting in faster response and improved control accuracy for the entire system.

[0020] As shown in the figure, the utility model is a contactless electronic switch control system for a crane, which is composed of a thyristor electronic thyristor contactless switch, a trigger control, a three-phase AC motor, a motor protector and a master command setting.

[0021] The entire vehicle has no contacts and can withstand environments with high temperature, large vibration, high dust and high water vapor; it has large starting torque and automatically captures the maximum torque output during startup; and its price is much lower than that of frequency conversion devices.

[0022] The control is safe. The control circuit is an electronic trigger circuit, all of which are low-voltage weak electricity (24V or 5V), which is lower than the safety voltage, ensuring the safety of operators.

[0023] The equipment has high protection. Each link of the entire system is completed by the program set in the module, achieving linear acceleration. It avoids excessive impact caused by driver operating habits or mistakes, protects the smooth operation of the motor, and also eliminates impact on the mechanical transmission mechanism, extending the service life of the machine.

[0024] The operation is simple, which reduces the driver's fatigue, improves the working efficiency and ensures safe operation. The operation method is completely consistent and the driver does not need special training. Even if irregular operation occurs during the operation, the module will still implement the optimal control principle to avoid accidents.

[0025] Significant energy saving: Metallurgical cranes are the main production equipment in the metallurgical industry. They are high-duty and have a power-on continuity rate of more than 60%. Considering medium-sized cranes, one crane can save about RMB 120,000 in spare parts costs and 70KWH of power throughout the year.

[0026] It is convenient for equipment management. The trigger control module unit can automatically record equipment operation data, which is convenient for equipment management and can be connected to the intelligent management of the user unit.

[0027] Working process of this utility model:

[0028] The main circuit, the three-phase power supply is connected to the circuit breaker, motor protector, fast fuse and electronic thyristor contactless switch in sequence, through the circuit breaker (set in the main control circuit position for main circuit isolation), motor protector, fast fuse (set in the main circuit position for short-circuit protection), thyristor contactless switch to the stator and rotor of the three-phase AC motor (used to control the operation of the crane), forming a contactless main circuit. The stopping, running and speed regulation of the three-phase AC motor are all completed by the thyristor contactless switch.

[0029] The thyristor contactless switch uses anti-parallel thyristors to replace the switching function of mechanical contacts. It is installed on an electronic heat sink to ensure that the thyristor contactless switch operates within a certain temperature range. The motor protector is located in the main circuit to monitor the motor's operating status and is also connected to the trigger control module's signal. During operation, the collected current signal triggers the control module, achieving closed-loop control.

[0030] Control circuit, the main command given signal is sent to the trigger control module, the trigger control module triggers the electronic thyristor contactless switch, and the thyristor contactless switch controls the stator and rotor of the motor after being triggered;

[0031] The trigger control module determines the brake control according to the set program to achieve zero-speed mechanical braking.

[0032] The electronic trigger control circuit is used without mechanical action, which speeds up the response speed of the control system and realizes closed-loop control.

[0033] The rotor speed is controlled by connecting two groups of thyristors in series and then connecting a small number of softening resistors. The rotor current is changed by triggering the conduction angle of the thyristors, which greatly simplifies the circuit. At the same time, only the softening resistors are retained, and the number of resistors is also greatly reduced.

[0034] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principles of the present invention. These improvements should also be regarded as within the scope of protection of the present invention.

Claims

1. The crane contactless electronic switch control system includes a main circuit and a control circuit, which is characterized by: The main circuit includes a three-phase power supply, a circuit breaker, a motor protector, a fast fuse, an electronic thyristor contactless switch and a three-phase AC motor connected in sequence. The motor protector is also connected to the trigger control module signal; The control circuit is an electronic trigger circuit, which is given by the master command signal to the trigger control module; The trigger control module gives the electronic thyristor contactless switch and brake control signals respectively, realizing the start, stop and speed regulation operation of the three-phase AC motor or brake control; Electronic thyristor contactless switches control the start and stop operations of the stator and rotor of three-phase AC motors.

2. The contactless electronic switch control system for a crane according to claim 1, characterized in that: The three-phase power supply is set at the main power supply position to power the equipment; The circuit breaker is set at the main control circuit position to isolate the main circuit; The motor protector is set in the main circuit position to monitor the motor operating status; The fast fuse is set in the main circuit position for short circuit protection; The electronic thyristor contactless switch is set on the electronic radiator and is used for forward and reverse control of the motor stator and rotor speed regulation; Three-phase AC motors are used to control crane operation.

3. The contactless electronic switch control system for a crane according to claim 1, characterized in that: The main circuit and the control circuit are both arranged on the linkage platform in the driver's cab.

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