KR100342172B1 - Moving switch controll device using pulse generator of induction motor - Google Patents

Abstract

The present invention relates to a start switch control apparatus for an induction motor using a pulse generator,

In the conventional centrifugal force switch used as a starting switch, the tension of the spring frequently changes according to external temperature, humidity, and various conditions, so that the operation timing of the centrifugal force switch is variable, As the number of contacts increases, the contact is damaged, causing the motor winding and the starting winding of the motor to overheat, causing the motor to break.

Accordingly, the present invention for solving the above problems comprises a pulse generator for generating a pulse in proportion to the rotational speed of the rotating shaft, and a means for counting the pulse generated by the pulse generator to turn off the start switch when a predetermined value or more induction motor The drive characteristics of the induction motor are improved by electronically detecting the on-off switching control at the exact time by accurately detecting that the motor reaches the target speed at which the motor turns off the starting winding during the initial driving of the motor. Since the start switch unit is intermittent, arcing does not occur during the switching operation, and thus the life of the product is extended. Also, the control device of the present invention is embedded in a separate pad, and the rear part of the motor body is connected to one side of the pad. Close the cylindrical part to be in close contact with the pulse generator By providing one light emitting element and a light receiving element, it relates to a start switch control device which improves the pulse generation reliability of the pulse generator by preventing foreign substances from being caught in each element.

Description

Moving switch controll device using pulse generator of induction motor

The present invention relates to a control device for a start switch of an induction motor using a pulse generator. In particular, the driving characteristics of the induction motor are improved, and the start switch part is electronically interrupted so that arcing does not occur during the switching operation, thereby improving the life of the product. Extends, and the control device of the present invention is embedded in a separate pad, and a cylindrical seal portion which is in close contact with the rear portion of the motor body is formed on one side of the pad to form a light emitting element and a light receiving element for generating pulses in the seal portion. The present invention relates to a start switch control device which improves the pulse generation reliability of a pulse generator by preventing foreign substances from being caught in each element.

In general, the induction motor starts driving by the electromotive force generated by the starting winding and the driving winding during the initial driving, and when the motor reaches a speed corresponding to about 75% of the target speed, the starting winding is turned off and the driving winding starts from this time. It is intended to work only by

1 shows a prior art for the enforcement of a maneuver winding;

The starting winding L2 and the driving winding L1 are wound on the motor M, and the starting winding L2 is connected to a starting switch 2 for controlling the operation of the starting winding L2. A rectifier 1, a resistor R1, and a capacitor C1 are configured to rectify AC power and supply them to respective control stages of the motor.

When the motor M is initially operated, since the start switch 2 is in the on state, the commercial AC power is supplied to the driving winding L1 and the starting winding L2 at the same time so that both windings L1 and L2 The electric motor M rotates by the generated electromotive force.

After the motor (M) starts to rotate, when the rotational speed of the motor (M) reaches a speed corresponding to about 75% of the maximum speed, the start switch (2) is turned off. It is driven only by L1).

As described above, a centrifugal force switch composed of an electrical contact, a spring, and a rotational bundle is used as the starting switch 2 for controlling the starting winding L2.

In the centrifugal force switch, when the electric motor M rotates, the centrifugal force is generated while the rotary bundle rotates, and when the centrifugal force becomes larger than the elasticity of the spring, the electrical contact is shorted and the starting winding L2 is turned off.

However, such a mechanical centrifugal force switch has a tension change frequently according to external temperature, humidity, and various conditions, and thus the operation timing of the centrifugal force switch is variable, and the number of electrical contacts is connected as the centrifugal force switch is used for a long time. As the contact point is increased and the driving winding L1 and the starting winding L2 of the motor are overheated, a problem occurs in which the motor is damaged.

Accordingly, the present invention for solving the above problems comprises a pulse generator for generating a pulse in proportion to the rotational speed of the rotating shaft, and a means for counting the pulse generated by the pulse generator to turn off the start switch when a predetermined value or more induction motor The drive characteristics of the induction motor are improved by electronically detecting the on-off switching control at the exact time by accurately detecting that the motor reaches the target speed at which the motor turns off the starting winding during the initial driving of the motor. Since the start switch unit is intermittently controlled, the start switch control device is configured to extend the life of the product by avoiding arcing during the switching operation.

In addition, by embedding the control device of the present invention in a separate pad, by forming a cylindrical sealing portion in close contact with the rear portion of the motor body on one side of the pad to install a light emitting element and a light receiving element for generating a pulse in the sealing portion It is an object of the present invention to provide a start switch control device for improving the pulse generation reliability of a pulse generator by preventing foreign substances from being caught in each element.

Features of the present invention for achieving the above object,

In an induction motor having a winding maneuver and a driving winding, the rear end of the rotating shaft is formed to protrude a predetermined length toward the rear frame side away from the body,

A pulse generator for generating a pulse in proportion to the rotational speed of the induction motor rotating shaft;

A reset unit generating and outputting a reset signal at a predetermined predetermined period;

A counter that counts the pulses generated by the pulse generator and is reset by a reset signal input from a reset unit, and outputs a predetermined counting signal when the counting value reaches a target value due to an increase in the rotational speed of the rotating shaft;

Start-up switch that keeps on during initial start-up so that power is supplied to the starting winding, and then is turned off by the input signal when the rotational speed of the rotating shaft reaches a certain value less than the maximum speed, so that the motor rotates only with the driving winding. Wealth;

A driving unit for delaying a predetermined time when the counting signal is input from the counter and turning off the start switch unit; Characterized in that consisting of.

The pulse generator forms a through hole at the rear end of the rotating shaft, and installs a light emitting element and a light receiving element so as to face each other at a position opposite to the center of the through hole, so that the light emitting element, the through hole, and the light receiving element are all aligned in a straight line. It is characterized in that a pulse is generated from the light receiving element whenever it is located.

In addition, the components are disposed on a substrate of a predetermined size, the substrate is formed in a predetermined size and embedded in the pad coupled to the coupling jaw of the rear frame as a bolt, to form a cylindrical seal on one side of the pad The light emitting element and the light receiving element are disposed at positions facing each other so as to be in close contact with the support plate supporting the rotating shaft.

1 is a circuit diagram showing the prior art.

Figure 2 is a circuit diagram showing a start switch control device of the present invention.

Figure 3 is an exploded cross-sectional view showing an installation of the present invention.

Figure 4 is a sectional view showing a state in which the start switch control device of the present invention is installed.

Figure 5 is a rear plan view of the motor showing the present invention mounted on the motor.

Figure 6 is a graph showing the relationship between the reset period and the rotational speed of the rotary shaft of the reset unit applied to the present invention.

Explanation of symbols for main parts of the drawings

M: electric motor, L1: driving winding,

L2: starting winding, 10: pulse generator,

11: reset part, 12: counter,

13: starting switch part, 14: driving part,

20: body, 21: axis of rotation,

22: through hole, 23: rear frame,

24: coupling jaw, 28: substrate,

29: pad, 31: sealing part,

D1: light emitting element, D2: light receiving element,

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, FIGS. 2 to 6.

Figure 2 is a circuit diagram showing a start switch control device applied to the present invention,

The pulse generator 10, the reset part 11, the counter 12, the start switch part 13, and the drive part 14 are comprised.

The pulse generator 10 generates pulses in proportion to the rotational speed of the rotation shaft 21 when the rotation shaft 21 of the motor M rotates, and includes the light emitting device D1 and the light emitting device D1. A light receiving element D2 for generating a pulse when light generated from the light is input, and an amplifier 10a for amplifying and supplying a pulse output from the light receiving element D2 to the counter 12.

The light emitting device D1 and the light receiving device D2 are installed to face each other with respect to the rotation shaft 21, and the through hole 22 is formed on the rotating shaft 21 where the light emitting device D1 and the light receiving device D2 are installed. 3) two pulses are generated in the light receiving element D2 each time the rotating shaft 21 is rotated once.

The reset unit 11 generates a reset signal every predetermined period RS set by the time constants of the resistors R15 and R16 and the capacitors C11 and C12 and outputs the reset signal to the counter 12 so that the counter 12 is reset. It is to be possible.

The counter 12 counts pulses output from the pulse generator 10, and is reset by a reset signal input from the reset unit 11, and the rotation speed of the rotation shaft 21 is increased so that the counting value is a target value. When reaches to generate a predetermined counting signal and outputs to the drive unit (14).

That is, the reset signal generation period RS of the reset unit 11 is a pulse counted by the counter 12 when the rotation speed of the rotation shaft 21 is a speed V1 corresponding to about 75% of the maximum rotation speed. Reset is outputted from the reset unit 11 before the counting value of the counter 12 reaches the target value before the rotation speed of the rotary shaft 21 reaches the target speed V1 by setting the number to reach the target value. When the rotational speed of the rotary shaft 21 reaches the target speed V1, a large number of pulses are generated in the pulse generator 10, so that the counting value in the counter 12 is reset. The target value is reached before, so that the counting signal can be supplied to the driver 14.

For example, if the target counting value of the counter 12 is set to '8', the counter 12 is not until the rotational speed of the rotary shaft 21 reaches the target speed V1, that is, the counting value is '7'. When it is below, it is reset by the reset signal so that the counting signal cannot be output. When the rotational speed of the rotary shaft 21 exceeds the target speed V1, the number of pulses generated per unit time in the pulse generator 10 increases. Therefore, the counter 12 may count up to '8' before the reset signal is input, thereby outputting a counting signal to the driver 14.

When the counting signal is input from the counter 12, the driving unit 14 turns off the start switch unit 13 by a delay for a predetermined time. The transistor Q1 and the transistor Q1 are turned on by the counting signal. Resistor R17 and capacitor C13 for on-charging and discharging the voltage supplied during the on-operation of the transistor and turning on the transistor Q2 after a predetermined time delay, and the transistor Q2 for on-operation by the discharge voltage of the capacitor C13. And a transistor Q4 that turns off when the transistor Q2 is turned on and cuts off the power supply so that the start switch section 13 is turned off.

The reason why the resistor R17 and the capacitor C13 are provided in the drive unit 14 to delay the start switch unit 13 by turning off the start switch unit 13 for a predetermined time from the time when the counter signal is generated in the counter 12 is the start switch unit 13. Is turned off and the motor M rotates only by the driving winding L1, but even if the rotation speed of the rotating shaft 21 is slightly lower than the target value due to the load, the starting winding L2 does not operate immediately and is delayed for a predetermined time so that the rotating shaft 21 When the rotational speed of) decreases to about 60% of the maximum speed, the start switch unit 13 is turned on and the start winding L2 is operated again.

As described above, the start switch unit 13 interrupts the start winding L2 by the on / off switching operation under the control of the drive unit 14, and is applied to the voltage supplied from the transistor Q4 of the drive unit 14. An optical coupler (13a) comprising a light emitting diode (D3) which is turned on and emits light by light, and a triac (TA1) which outputs a predetermined control signal when light generated from the light emitting diode (D3) is inputted, and the optical coupler It consists of a triac TA2 which is operated on when the control signal output from 13a is input so that power is supplied to the starting winding L2.

That is, the optocoupler 13a and the triac TA2 of the start switch section 13 are turned on by the voltage supplied from the transistor Q4 before the rotation shaft 21 reaches the target speed, and thus the start winding L2. This operation is performed so that the rotational shaft 21 reaches the target speed and is turned off when the transistor Q4 is turned off and the voltage is not supplied so that the starting winding L2 does not operate.

Unexplained reference numerals R11 to R25 are resistors, C11 to C14 are capacitors, Q3 are transistors, and the same components are denoted by the same reference numerals.

On the other hand, Figure 3 and Figure 4 shows a state in which the start switch control device of the present invention is installed, a hemispherical rear frame 23 is formed at the rear end of the motor body 20, the rotating shaft 21 is a body ( 20, a predetermined length protrudes toward the rear frame 23 side.

A support plate 27 for supporting the rotating shaft 21 is formed at the boundary between the body 20 and the rear frame 23, a bearing 26 is formed between the supporting plate 27 and the rotating shaft 21, The support plate 27 is formed with a suction hole 25 to allow external air to be supplied to the inside of the body 20 and to be cooled when the electric motor M is driven.

In addition, a through hole 22 for generating pulses of the light emitting element D1 and the light receiving element D2 is formed at the rear end of the rotation shaft 21.

Reference numeral 29 denotes a pad 29 incorporating the substrate 28 on which the start switch control device of the present invention is disposed, and the pad 29 is preferably completely sealed to prevent foreign substances from being supplied to the substrate 28. .

On one side of the pad 29, a cylindrical sealing part 31 made of a rubber material is formed to protrude, and the light emitting device D1 and the light receiving device D2 are disposed at positions facing each other inside the sealing part 31. Install.

Therefore, when the pad 29 is coupled to the engaging jaw 24 of the rear frame 23 as the bolt 30, the bottom surface of the sealing part 31 is in close contact with the support plate 27, and the inside of the sealing part 31 is external. Since the electric motor (M) is completely blocked and the external air is supplied into the body 20 through the suction hole 25, foreign matter does not penetrate into the sealed part 31 at all, so that the light emitting device D1 ) And the light receiving element D2 can function properly, so that the light emitting element D1, the through hole 22, and the light receiving element D2 are present at the same height or higher.

5 is a view showing a state in which the pad 29 is coupled to the engaging jaw 24 of the rear frame 23, the pad 29 is engaged by the bolt 30 while being inscribed in the rear frame 23, It can be seen that the rear end of the rotating shaft 21 is accommodated in the seal 31.

6 shows the relationship between the reset period RS of the reset signal output from the reset unit 11 applied to the present invention and the rotational speed of the rotary shaft 21. The reset period RS is a target of the rotary shaft 21. As shown in FIG. It can be seen that it is set to correspond to the speed V1 (speed at which the rotation speed of the rotating shaft reaches about 75% of the maximum speed).

Accordingly, the counter 12 is not reset by the reset signal until the rotating shaft 21 exceeds the target speed V1, thereby preventing the counting signal from being output to the driving unit 14, and the rotating shaft 21 has the target speed V1. When the counter 12 is exceeded, the counter 12 counts up to a target value before the reset signal is input, and outputs a predetermined counting signal to the driving unit 14 so that the start switch unit 13 is turned off so that the start winding L2 does not operate. It will not be.

Referring to the operation of the present invention configured as described above is as follows.

In the initial state, the start switch section 13 is turned on by the power supplied from the transistors Q3 and Q4 of the drive section 14 in the on state so that power is supplied to the start winding L2.

Therefore, at the time of initial driving, power is supplied to both the starting winding L2 and the driving winding L1 so that the electric motor M is driven by the electromotive force generated in the starting winding L2 and the driving winding L1.

When the motor M is driven, the rotating shaft 21 starts to rotate, and at the same time as the rotating shaft 21 rotates, the pulse generator 10 generates a pulse proportional to the rotating speed of the rotating shaft 21.

The pulse generated by the pulse generator 10 is generated whenever the light emitting element D1, the through hole 22, and the light receiving element D2 all match, and this pulse is generated by two pulses each time the rotating shaft 21 rotates once. Occurs.

The pulse generated by the pulse generator 10 is counted by the counter 12. At this time, the counter 12 is reset by a reset signal supplied at a predetermined period and prevents counting the pulse to a target value.

Subsequently, when the rotational speed of the rotation shaft 21 gradually increases and exceeds the target speed V1 corresponding to about 75% of the maximum speed, the number of pulses generated by the pulse generator 10 increases by the counter 12. Before the reset signal is input, the target value is counted, and the target value is counted and a predetermined counting signal is output to the driver 14.

The driving unit 14 receiving the counting signal delays the predetermined time by the time constant set by the resistor R17 and the condenser C13, and then turns off the transistor Q4. 13a), no more voltage is supplied, so that the triac TA2, which is a contactless switch, is turned off, and thus the power supplied to the starting winding L2 is cut off.

At this time, the electric motor M is operated only by the driving winding L1.

In the present invention, since the light emitting element D1 and the light receiving element D2, which are the main parts of the pulse generator 10, are provided in the sealing portion 31 of the pad 29, the electric motor M as described above. Even when the) is operated, foreign matters such as dust or leaves do not penetrate into the sealing part 31, so that the light emitting device D1 and the light receiving device D2 may be semi-permanently operated.

As described above, the present invention comprises a pulse generator for generating a pulse in proportion to the rotational speed of the rotating shaft, and a means for counting the pulse generated by the pulse generator to turn off the start switch when a predetermined value is exceeded. The driving characteristics of the induction motor can be improved by electronically detecting the on-off switching control at the exact time by accurately detecting the target speed at which the motor starts to turn off the start winding. Since the interruption prevents the arc from occurring during the switching operation, the life of the product is extended, and the control device of the present invention is embedded in a separate pad, and the cylindrical surface which is in close contact with the rear part of the motor body to one side of the pad. Light emitting element for generating pulse in the sealed part by forming the sealed part of Hameuroseo so as to install the light-receiving element, not caught foreign matter in each element is a start switch by the controller to improve the reliability of the pulse generator a pulse generator.

Claims (4)

In the induction motor having a starting winding (L2) and the driving winding (L1), the rear end of the rotating shaft 21 is formed to protrude a predetermined length toward the rear frame 23, away from the body 20, A pulse generator 10 generating pulses in proportion to the rotational speed of the induction motor M; A reset unit 11 for generating and outputting a reset signal at predetermined predetermined periods; The pulse generated by the pulse generator 10 is counted, and is reset by a reset signal input from the reset unit 11. When the counting value reaches a target value due to an increase in the rotational speed of the rotating shaft 21, a predetermined counting is performed. A counter 12 for outputting a signal; On initial start-up, the state is maintained so that power is supplied to the starting winding. Then, when the rotational speed of the rotating shaft 21 reaches a predetermined value smaller than the maximum speed, the motor M turns off by the input signal. A starting switch section 13 for rotating only by L1; A driving unit 14 which delays a predetermined time when the counting signal is input from the counter 12 and then turns off the start switch unit 13; Characterized in that consisting of. In addition, the pulse generator 10 forms a through hole 22 at the rear end of the rotating shaft 21, and faces the light emitting device D1 and the light receiving device D2 so as to face each other at a position opposite to the center of the through hole 22. When the rotating shaft 21 is rotated so that the light emitting element (D1), the through hole 22, the light receiving element (D2) are all located in a straight line, the pulse is generated from the light receiving element (D2) Start switch control device of induction motor using pulse generator. The light emitting device (D1) and the light receiving device according to claim 1, wherein the pulse generator (10) forms a through hole (22) at a rear end of the rotating shaft (21), and faces each other at a position opposite to the center of the through hole (22). (D2) is provided so that a pulse is generated from the light receiving element D2 whenever the light emitting element D1, the through hole 22, and the light receiving element D1 are all located in a straight line when the rotating shaft 21 rotates. Start switch control device for induction motor using a pulse generator, characterized in that. The method of claim 1, The components are disposed on a substrate 28 having a predetermined size, and the substrate 28 is formed with a predetermined size and is coupled to the coupling jaw 24 of the rear frame 23 as a bolt 30. It is embedded inside, but one side of the pad 29 to form a cylindrical sealing portion 31 so as to be in close contact with the support plate 27 supporting the rotating shaft 21, the light emission inside the sealing portion (3) A start switch control device for an induction motor using a pulse generator, characterized in that the element (D1) and the light receiving element (D2) are provided at positions facing each other. The light emitting diode (D3) of claim 1, wherein the start switch unit (13) emits light by turning on / off by a signal output from the driving unit (14), and the light generated by the light emitting diode (D3) An optical coupler 13a composed of a triac TA1 which outputs a predetermined control signal when inputted thereto; A triac (TA2) for selectively supplying power to the starting winding (L2) by turning on / off depending on whether the control signal output from the optical coupler (13a) is input; Start switch control device of the induction motor using a pulse generator, characterized in that consisting of.