CN201298821Y - Slippage controller with an over-speed protection function - Google Patents

Abstract

The utility model discloses a slip controller with an overspeed protection function, which comprises a speed setting unit, a speed feedback unit, a comparison, amplification, phase shift trigger unit and a slip current unit. At the same time, it is also equipped with an overspeed given unit, an overspeed comparison unit, an overspeed detection unit and a protection action unit. The feedback signal of the speed feedback unit is compared with the given signal of the overspeed given unit through the overspeed comparison unit. After the comparison, the overspeed detection unit The detection is carried out, and the detection result is sent to the protection action unit, and the prime mover is controlled through the output signal of the protection action unit. The utility model solves the problem that the driven shaft and the driving shaft of the slip motor run synchronously or the driven shaft deviates from the normal operating speed range, and the problem of inability to alarm in time and automatically stop working. It not only saves human resources, but also avoids the harm caused by the equipment working at abnormal speed, prolongs the service life of the equipment, and improves the rationality of the process control of the equipment.

Description

A slip controller with overspeed protection function

technical field

The utility model relates to the field of motor control, in particular to an automatic alarm control device for a slip motor.

Background technique

Slip motor is a constant torque AC stepless variable speed motor, which is mainly composed of three parts: ordinary squirrel cage asynchronous motor, electromagnetic slip clutch and electrical control device. The asynchronous motor is used as the prime mover. The electromagnetic slip clutch is composed of two parts: the armature and the magnetic pole. The armature is a cylindrical structure made of cast steel. It is connected with the shaft of the squirrel-cage asynchronous motor, commonly known as the active part; the magnetic pole It is made into a claw-shaped structure and installed on the load shaft, commonly known as the driven part. The electrical control device is a device that provides excitation current for the slip clutch. The output speed of the clutch is adjusted by adjusting the current in the clutch excitation winding through the thyristor control device. . There is no mechanical connection between the active part and the driven part. When the prime mover drives the armature of the clutch to rotate, the magnetic poles of the driven part will follow the armature of the active part to rotate together. Slip motor has a series of advantages such as wide range of speed regulation, smooth speed regulation, large starting torque, small control power, and high mechanical property hardness in the automatic adjustment system with speed negative feedback, and has been widely used in various production fields. For example: In the KM rotary kiln cooler unloading system, a slip motor is used to drive the lantern gear to unload.

Due to the small gap between the armature and the magnetic pole, generally about 0.5mm, and the increase in the wear gap of the lantern gear transmission bearing and the large dust in the lower part of the cooler, it is easy to cause the armature and the magnetic pole to stick together, so that the driven shaft and the prime mover are driven. The shafts run synchronously, the lantern gear feeding speed is accelerated, and the feeding volume is increased, which eventually leads to accidents such as overload of the chain conveyor and leakage of the cooler. For this reason, it is often necessary to monitor manually, which not only wastes human resources, but also causes equipment damage due to untimely alarms and abnormal operation of the equipment.

Contents of the invention

The purpose of this utility model is to provide a slip controller with an overspeed protection function to solve the problem that when the driven shaft of the slip motor runs synchronously with the driving shaft or the driven shaft deviates from the normal operating speed range, it cannot alarm in time and stop working automatically The problem.

The purpose of this utility model is achieved in this way, a slip controller with overspeed protection function, including speed given unit, speed feedback unit, comparison, amplification, phase shift trigger unit and slip current unit, the speed given unit The given signal of the unit is compared with the feedback signal of the speed feedback unit through the comparison unit, and the compared difference is amplified, phase-shifted and triggered to control the thyristor of the slip current unit to perform half-wave rectification to adjust the excitation current of the slip clutch , which is characterized in that it is also provided with an overspeed given unit, an overspeed comparison unit, an overspeed detection unit and a protection action unit, and the feedback signal of the speed feedback unit is compared with the given signal of the overspeed given unit through the overspeed comparison unit. After the comparison, the The overspeed detection unit performs detection, and the detection result is sent to the protection action unit, and the prime mover is controlled through the output signal of the protection action unit.

The utility model compares the speed feedback signal with the set speed limit value, and when the speed feedback signal exceeds the range of the set speed limit value, an alarm signal is sent and the prime mover is controlled to stop rotating, so that the driven motor of the slip motor is solved. When the shaft and the driving shaft run synchronously or the driven shaft deviates from the normal operating speed range, the problem of not being able to alarm in time and automatically stop working. It not only saves human resources, but also avoids the harm caused by the equipment working at abnormal speed, prolongs the service life of the equipment, and improves the rationality of the process control of the equipment.

Description of drawings

Fig. 1 is the block diagram of slip controller of the present utility model;

Fig. 2 is a control schematic diagram of an embodiment of the utility model;

Fig. 3 is a control schematic diagram of another embodiment of the utility model.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described.

As shown in Figure 1, a slip controller with an overspeed protection function of the utility model includes a speed setting unit 6, a speed feedback unit 13, a comparison, amplification, phase shift trigger unit 7 and a slip current unit 8. The given signal of the speed given unit 6 is compared with the feedback signal of the speed feedback unit 13 through the comparison, amplification, and phase-shift trigger unit 7, and the difference after comparison is amplified and phase-shifted to trigger control of the controllable slip current unit 8. Silicon carries out half-wave rectification to adjust the magnitude of the excitation current of the slip clutch 4. It is characterized in that it is also provided with an overspeed given unit 9, an overspeed comparison unit 10, an overspeed detection unit 11 and a protection action unit 12, and the feedback signal of the speed feedback unit 13 It is compared with the given signal of the overspeed setting unit 9 through the overspeed comparison unit 10, and after the comparison, it is detected by the overspeed detection unit 11, and the detection result is sent to the protection action unit 12, and the prime mover 5 is controlled by the output signal of the protection action unit 12. control. The problem that the driven shaft of the slip motor with load 1 and the driving shaft of the prime mover 5 run synchronously or the driven shaft deviates from the normal operating speed range cannot be alarmed in time and automatically stop working.

As shown in Figure 1, the utility model utilizes the tachogenerator 3 to change the output speed n of the clutch 4 into an AC voltage V~, and then becomes a DC voltage-Vnf1 through a rectifier. Send -Vnf1 into the comparison unit, and compare it with the given DC excitation voltage +Vgd. Get the voltage difference ΔV. So the excitation current If of the slip clutch is not proportional to the excitation voltage +Vgd, but proportional to the voltage ΔV. Since the size of V ~ (-Vnf1) is related to the speed n, as n increases, V ~ (-Vnf1) becomes larger. n decreases, V ~ (-Vnf1) becomes smaller. Therefore, under the condition that the given DC excitation voltage +Vgd remains unchanged, the magnitude of the excitation current If of the slip clutch is related to the speed n, that is, as n decreases or increases, the excitation current If will automatically increase or decrease, due to negative The function of feedback improves the hardness of the mechanical characteristics of the electromagnetic clutch. At this time, the speed regulation parameter is no longer the current If but the voltage +Vgd. Obviously, the higher the given excitation voltage +Vgd, the higher the speed n; otherwise, the speed lower. When the overspeed protection device is activated, the set speed limit value is compared with the speed feedback value. When the speed deviates from the limit of the normal working range (Vnf>Vsd), the relay operates, and the passive contact of the relay is used to stop the prime mover. Or send out an alarm; when the speed is in the normal working range (Vnf<Vsd), the coil of the control micro-relay will not be energized, so that the prime mover works normally or does not send out an alarm signal.

As shown in Figure 1, the utility model has a slip controller with an overspeed protection function, wherein the speed feedback unit compared with the overspeed given unit 9 can adopt two forms, one is a speed feedback unit 13 composed of a tachogenerator 3 The other is composed of a variable resistor increased in the interior, and the other is composed of a speed measuring device 2 directly installed on the slip clutch 4 output shaft. When in use, it is selected through the jumper switch S2. Similarly, the overspeed given unit 9 can also adopt two forms, one is made up of a variable resistor added in the speed given unit 6, and the other is made up of a DC power supply and a variable resistor. When in use, it is selected through the jumper switch S1.

As shown in Figure 1, the utility model has a slip controller with an overspeed protection function, its overspeed detection unit 11 is composed of a comparison link, a detection and judgment link, a signal amplification and an output link, and the protection action unit 12 is composed of a signal receiving link , SCR control output links.

As shown in Figure 2, the overspeed detection unit is an operational amplifier type. When the overspeed detection unit and the protection action unit are switched on (K1 is closed), the set speed limit value is compared with the speed feedback value. When the speed deviates from the limit of the normal working range (Vnf>Vsd), the operational amplifier F1 outputs a negative saturation signal. Transistor T1 is turned off, and capacitor C is charged by R5 and R6. When the capacitor voltage reaches the peak voltage of unijunction transistor T2, unijunction transistor T2 is turned on, and a sharp pulse is formed at R9 to turn on the thyristor SCR, and the ZJ relay operates. Its ZJ passive contact is used to stop the prime mover or issue an alarm. When the speed is within the normal operating range (Vnf<Vsd), the operational amplifier F1 outputs a positive saturation signal, the transistor T1 is turned on, the capacitor C is discharged through the transistor T1, the unijunction transistor T2 is turned off, the thyristor SCR is turned off, and the control micro-relay coil cannot Electricity, so that the prime mover works normally or does not send out an alarm signal.

As shown in Figure 3, the overspeed detection unit is a crystal transistor type. When the overspeed detection unit and the protection action unit are switched on (K1 is closed), the set speed limit value is compared with the speed feedback value. When the speed deviates from the limit of the normal working range (Vnf>Vsd), the transistor T1 is turned on, and the transistor T2 is turned off. , the transistor T3 is cut off, and the capacitor C is charged by R9 and R10. When the capacitor voltage reaches the peak voltage of the unijunction transistor T4, the unijunction transistor T4 is turned on, and a sharp pulse is formed in R13 to turn on the thyristor SCR, and the ZJ relay operates , Its ZJ passive contact is used to stop the prime mover or issue an alarm. When the speed is in the normal working range (Vnf<Vsd), the transistor T1 is cut off, the transistor T2 is turned on, the transistor T3 is turned on, the capacitor C is discharged through the transistor T3, the unijunction transistor T4 is cut off, and the thyristor SCR is cut off to control the micro relay coil No electricity, so that the prime mover works normally or does not send out an alarm signal.

Claims (7)

1. A slip controller with an overspeed protection function, comprising a speed setting unit (6), a speed feedback unit (13), a comparison, amplification, phase shift trigger unit (7) and a slip current unit (8), The given signal of the speed given unit (6) is compared with the feedback signal of the speed feedback unit (13) through the comparison unit, and the difference after comparison is amplified and phase-shifted to trigger control of the controllable slip current unit (8). Silicon performs half-wave rectification to adjust the magnitude of the excitation current of the slip clutch (4), and is characterized in that it is also provided with an overspeed given unit (9), an overspeed comparison unit (10), an overspeed detection unit (11) and a protection action unit (12 ), the feedback signal of the speed feedback unit (13) is compared with the given signal of the overspeed given unit (9) through the overspeed comparison unit (10), and after comparison, the overspeed detection unit (11) performs detection, and the detection result is sent to The protective action unit (12) controls the prime mover (5) through the output signal of the protective action unit (12). 2. The slip controller with overspeed protection function according to claim 1, characterized in that the speed feedback unit compared with the overspeed given unit (9) is a tachogenerator (3) speed feedback unit (13) Composed of variable resistors added inside. 3. The slip controller with overspeed protection function according to claim 1, characterized in that the speed feedback unit compared with the overspeed given unit (9) is directly installed on the output shaft of the slip clutch (4) The speed measuring device (2) is formed. 4. The slip controller with overspeed protection function according to claim 1, characterized in that the overspeed setting unit (9) is composed of a variable resistor added in the speed setting unit (6). 5. The slip controller with overspeed protection function according to claim 1, characterized in that the overspeed given unit (9) is composed of a DC power supply and a variable resistor. 6. The slip controller with overspeed protection function according to claim 1, characterized in that the overspeed detection unit (11) is composed of a comparison link, a detection and judgment link, a signal amplification and an output link. 7. The slip controller with overspeed protection function according to claim 1, characterized in that the protection action unit (12) is composed of a signal receiving link and a thyristor control output link.

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