KR100879535B1 - Electric motor actuator - Google Patents

Abstract

The present invention relates to an electric actuator that opens and closes a valve by a power supply. More specifically, an IGBT is used as a power device for controlling a speed or power supply of a motor, and a short circuit current is generated in the IGBT due to a burnout of the motor or a user error. However, if excessive current flows, the IGBT is immediately cut off (turned off) to prevent damage to the IGBT. By employing a single transistor (switching element) as a single part, the propagation delay is minimized. Is not broken,

Zener diode or shunt regulation IC is used to regulate the magnitude of the driving signal input to the gate stage of the IGBT uniformly, and the linear regulation IC and its peripheral circuit components such as 7815 to stabilize the driving voltage as a whole are simplified. The present invention relates to a motor speed control type electric actuator using IGBT, which has reduced cost.

Motor speed control type electric actuator using IGBT of the present invention

An electric actuator comprising a motor as a driving source, an output member connected to the valve to open and close the valve, a power transmission member to transmit the power of the motor to the output member, and a motor control circuit to control the operation of the motor. To

The motor control circuit includes a microcomputer for outputting a control signal; An IGBT for regulating the operation speed and power supply of the motor; And an IGBT driving circuit unit receiving the PWM signal from the microcomputer and driving the IGBT according to the received PWM signal.

The IGBT driving circuit unit is connected to a receiving unit receiving a PWM signal from the microcomputer, and a first switching device connected to the gate terminal of the IGBT, respectively, and turned on / off by opposite output signals of the receiving unit to drive the IGBT. And a driving unit including a second switching element, and a base end connected to the collector end of the IGBT, and a collector end connected to the base end of the first switching element, and when a current larger than a reference value flows through the IGBT, the turn-on is turned on. And a protection part including a third switching device which maintains a turn-off state of the first switching device to prevent breakage of the IGBT.

Electric Actuator, IGBT, Propagation Delay, Zero Adjustment Means

Description

Motor Speed Control Electric Actuator Using ITV [ELECTRIC MOTOR ACTUATOR}

1 is a schematic circuit diagram of a motor control circuit according to the present invention;

2 is a schematic internal parts perspective view of the actuator according to the present invention;

Figure 3 is an exploded perspective view of the main portion of the driven gear and the elastic member of the slip type zero adjustment means according to the present invention,

4 is a cross-sectional view and a bottom view of a main portion for explaining the state of the holding state of the input shaft by the elastic member in the slip type zero point adjustment means according to the present invention.

<Description of the symbols for the main parts of the drawings>

1: power transmission means 2: output member

11: Relay shaft 13: Relay gear

20: potentiometer (measuring device) 21: input shaft

21a: tool coupling groove 30: driven gear

31: shaft 33: receiving portion

40: elastic member 41: elastic reinforcement bending portion

43: end 51: IGBT

52: microcomputer 60: IGBT driving circuit

61: receiver 62: driver

63: protection

The present invention relates to an electric actuator that opens and closes a valve by a power supply. More specifically, an IGBT is used as a power device for controlling a speed and a power supply of a motor, and a short circuit current is generated in the IGBT due to a burnout of the motor or a user mistake. However, if excessive current flows, the IGBT is cut off (turned off) immediately to prevent damage to the IGBT, and a single component transistor (one switching element) is adopted to minimize propagation delays before operating the protection part. IGBT is not broken,

A motor speed control type electric actuator using an IGBT that uses a Zener diode or a shunt regulation IC to regulate the magnitude of the driving signal input to the gate end of the IGBT constantly and reduces the cost by simplifying the circuit components as a whole. will be.

The present invention also relates to a motor speed control type electric actuator using an IGBT, which further includes a zero point adjusting device for convenient zero point checking and zero point adjustment of a potentiometer for measuring the opening and closing state of a valve. will be.

In general, actuators are used to open and close valves such as ball valves and rotary machines such as dampers.

As a driving source for opening and closing the valve, the actuator is provided with a motor, and the operation of the motor is controlled by the motor control circuit.

Recently, a power device (eg, IGBT, MOSFET, FET, SCR) is mainly used to control the driving speed of the motor, and the power device controls the driving speed of the motor by a pulse width modulation (PWM) method.

In the field requiring precise control of motor operation and high power, IGBT (Insulated Gate Bipolar Transistor) is mainly used as a power device with high breakdown voltage, suitable for high voltage and high current, and low noise.

IGBT is an expensive product, which accounts for a large part of the cost of the motor control circuit.

Therefore, it is common to provide a protection unit in the driving circuit unit for driving the IGBT to prevent the IGBT from being damaged due to short circuit current or excessive current flowing through the IGBT due to a burnout of the motor or a user mistake.

The protection unit senses a current flowing in the IGBT, and prevents damage to the IGBT by blocking a driving signal input to the IGBT when the sensed current exceeds a reference value.

The energy I ^ T * T breaking the IGBT is proportional to the square of the current I flowing through the IGBT and the time T. Therefore, in order to prevent damage to the IGBT, the operation of the protection unit should be started quickly, and the IGBT should be shut off (turned off) quickly.

However, the conventional actuator uses an IC chip as a protection part of the motor control circuit, and the IC chip is a chip in which various electronic components are integrated, and the propagation delay is long, so that the IGBT may not be sufficiently prevented from being damaged. In addition, since the IC chip is expensive, the cost of the motor control circuit is increased.

In addition, the conventional actuator is used with a linear regulation IC together with a DC-DC converter or a switching regulator to stabilize the driving voltage of the IGBT. These actuators are made of various electronic components such as an electrolytic capacitor to precisely regulate the driving voltage. As a result, the cost of the motor control circuit is increased.

In addition, in the conventional actuator, in addition to the instrument panel provided in the actuator to check the open and close state and the opening degree of the valve, it is possible to check the operating state of the actuator in the central control panel for remote control. The potentiometer is adopted.

The potentiometer is usually connected to a relay shaft which is interlocked with the output member of the actuator connected to the valve by a gear.

In the case of the initial assembly and installation of each part and the disassembly and joining of the maintenance, etc., it is necessary to readjust the set zero point corresponding to the reference position (open or closed position) of the gate.

Conventionally, the potentiometer of the actuator adopts a model in which the input shaft pivoted by the relay shaft is endless type. (This means that even when the valve opening and closing position is outside the limit position of the potentiometer, the power of the motor As it is transmitted continuously, endless type is adopted to prevent damage of the potentiometer.)

In the case of zero adjustment, it was cumbersome and inconvenient because the adjustment work must be performed using a separate measuring device.

The present invention has been made to solve the above-mentioned conventional problems,

It detects the current flowing through the IGBT of the motor control circuit and cuts off the IGBT when the current exceeds the reference value, and protects the IGBT by adopting a single component transistor to minimize propagation delay to prevent damage to the IGBT and to reduce cost. Is to provide an improved electric actuator,

It is an object of the present invention to provide an electric actuator having a zero adjustment means in which zero adjustment of a potentiometer is easily performed.

Motor speed control type electric actuator using the IGBT of the present invention for achieving the above object is

An electric actuator comprising a motor as a driving source, an output member connected to the valve to open and close the valve, a power transmission member to transmit the power of the motor to the output member, and a motor control circuit to control the operation of the motor. To

The motor control circuit includes a microcomputer for outputting a control signal;

An IGBT for controlling a power supply to a load or a load of the motor;

And an IGBT driving circuit unit receiving the PWM signal from the microcomputer and driving the IGBT according to the received PWM signal.

The IGBT driving circuit unit receives a PWM signal from the microcomputer and a receiving unit;

A driving unit connected to the gate terminal of the IGBT, each of which includes a first switching element and a second switching element which are turned on / off in opposition to each other by an output signal of the receiver to drive the IGBT;

When the base end is connected to the collector end of the IGBT, and the collector end is connected to the base end of the first switching device so that a current larger than a reference value flows through the IGBT, the base is turned on to maintain the turn-off state of the first switching device. And a protection part including a third switching device to prevent breakage of the IGBT.

A relay shaft connected to the output member and having a relay gear;

An input shaft connected to the potentiometer;

A driven gear having a shaft hole having a cross-sectional area larger than that of the input shaft, and a receiving portion formed around the shaft hole, the driven gear meshing with the relay gear of the relay shaft; And

And a slip type zero point adjusting means, comprising: an elastic member arranged at a receiving portion of the driven gear to press the input shaft so that the rotational motion of the relay shaft is transmitted to the input shaft.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 shows a motor control circuit according to the present invention, and is shown mainly in the IGBT driving circuit unit.

Figure 2 is a perspective view of the internal parts of the actuator related to the potentiometer for indicating the opening and closing state of the slip-type zero point adjustment means according to the present invention, the gate ( The output member 2 to be finally delivered toward (not shown), and the components for transmitting the rotational movement from the output member to the potentiometer 20 again.

3 is an exploded perspective view of main parts of the driven gear and the elastic member of the slip type zero point adjusting means according to the present invention, in particular, [A], [B], and [C] in three circles, respectively. A plan view, a side view, and a side cross-sectional view (incision along the AA line in [B]) are shown.

[A] and [B] of Fig. 4 are combined cross-sectional views and bottom views of the main parts for explaining the state of the input shaft squeezed by the elastic member in the slip type zero point adjusting device according to the present invention, and in particular, [B] In order to help understand the coupling relationship according to the relative cross-sectional area of, the input shaft 21 of the potentiometer is shown.

First, the motor control circuit will be described with reference to FIG.

The motor control circuit is electrically connected to the motor, there is an IGBT 52 for adjusting the operating speed of the motor by the frequency change by the turn-on (conduction) turn-off (blocking),

There is a microcomputer 51 that outputs a control signal in accordance with the user's operation signal and the rotational speed of the feedback motor,

An IGBT driving circuit unit 60 receives the PWM signal processed by the control signal from the microcomputer 51 and outputs a driving signal to the gate terminal of the IGBT according to the received PWM signal to drive the IGBT.

Although not shown in the drawing, when the actuator uses a commercial AC power supply, a power conversion unit for converting the commercial AC power to DC power is connected to the power input terminal VCC.

The IGBT driving circuit unit 60 includes a receiver 61, a driver 62 and a protection unit 63,

The receiver 61 is a photocoupler including a photodiode D1 receiving a PWM signal from the microcomputer 51 and a phototransistor Q1 turned on / off by the photodiode D1.

The use of the photocoupler as the receiver 61 is to electrically insulate the microcomputer 51 and the IGBT driving circuit unit 60 from each other. In particular, actuators using a high voltage of 110V or higher need to use a photocoupler or a pulse trans to satisfy the circuit operation stability and the global standard.

The driver 62 has an emitter terminal and a collector terminal respectively connected to the gate terminal G of the IGBT 52, and are turned on / off in opposition to each other by an output signal of the receiver 61 to drive the IGBT. And a first switching element Q6 and a second switching element Q7. For reference, the transistor Q5 forms a dialing pair together with the first switching element Q6. Since this is a known technology, description thereof will be omitted.

When the phototransistor Q1 of the receiver 61 is turned on, the relay transistor Q4 is turned off, and when the relay transistor Q4 is turned off, the first switching device Q6 is turned on to turn on the IGBT 51. ,

When the phototransistor Q1 of the receiver 61 is turned off, the relay transistor Q4 is turned on, and when the relay transistor Q4 is turned on, the second switching element Q7 is turned on to turn off the IGBT 52. do.

A zener diode D5 for regulating the magnitude of the driving signal input to the gate terminal G of the IGBT 51 is connected to the base terminal of the first switching element Q6 in parallel. The zener diode D5 cuts a voltage exceeding a predetermined size, thereby driving voltage (that is, a driving signal) input to the gate terminal G of the IGBT 51 through the first switching device Q6. ) Will not exceed a certain size. This is also achieved using the 431 Shunt Regulation IC.

The protection unit 63 detects a current flowing in the IGBT 51, removes the gate driving energy of the IGBT when the detected current exceeds a predetermined amount, and turns off the first switching element Q6 to turn off the IGBT ( 51) so that the driving voltage is no longer input to the gate end G of 51),

The IGBT 51 is cut off (turned off) to prevent current from flowing through the IGBT 51, thereby preventing the IGBT 51 from being damaged.

The protective part 63 has a base end connected to the collector end C of the IGBT 51, and a collector end connected to the base end of the first switching element Q6, so that the IGBT 51 has a reference value. A third switching element Q2 which is turned on when a large current flows to maintain the turn-off state of the first switching element Q6 to prevent breakage of the IGBT 51;

A base end is connected to the receiver 61, and a collector end is connected to the base end of the third switching element Q2, and is turned on when the third switching element is turned on to malfunction of the third switching element Q2. It comprises a fourth switching element (Q3) to prevent the.

The third switching element Q2 is normally turned off,

When a current equal to or greater than the reference value flows through the IGBT 51 and the base end of the third switching element Q2 becomes equal to or greater than a predetermined voltage, the IGBT 51 is turned on to turn off the first switching element. The turn-on state is maintained until the base terminal of the third switching element Q2 falls below a predetermined voltage.

In addition, by adjusting the size of the resistor R4 connected to the base end of the third switching element Q2, a reference value of the current magnitude flowing through the IGBT 51 in which the third switching element Q2 is operated may be set.

The fourth switching device Q3 is normally turned off, but when the third switching device Q2 is turned on and the IGBT 52 is turned off, the fourth switching device Q3 is turned on to malfunction of the third switching device Q2. prevent.

In the capacitor C4 connected between the third switching element Q2 and the IGBT 51, the short switching current or overcurrent flows more quickly than the reference value to the IGBT 51 by the discharge of the charged voltage. To sense,

The capacitor C3 connected between the receiver 61 and the driver 62 is also used so that the output signal of the transistor Q1 of the receiver 61 is transmitted to the relay transistor Q4 more quickly. That is, to reduce the delay time of the signal.

The capacitors C1 and C2 are charged and discharged by the input power of the input terminal to supply power for the IGBT driving circuit unit.

Hereinafter, with reference to Figures 2 to 4 will be described a zero point adjustment means that can be another feature of the present invention.

In describing the zero point adjusting means according to the present invention, the direction reference is specified with reference to FIGS. 2 and 4.

The tool engagement groove 21a of the input shaft 21 in the coupling relationship between the potentiometer 20 and the driven gear 30 in which the elastic member 40 having a substantial zero adjustment function is incorporated (the shape shown is a straight line) The upper side for the driver should be on the top and the other side on the bottom.

First, Figure 2 shows a part of the internal parts of the actuator according to an embodiment of the present invention,

The power transmission means (1) consisting of an output member (2) connected to the valve and a reduction gear group for transmitting the power of the motor to the output member (2) does not differ from the conventional actuators, so a detailed description thereof will be omitted.

Zero adjustment means according to the invention

An output member 2 which receives the rotational force of the motor (not shown) in a decelerated form and turns the valve (not shown);

In order to transmit the opening or closing of the valve to the central control panel in the remote position, the power transmission member, in particular the potentiometer, arranged between the potentiometer 20 pivoted in accordance with the turning of the output member (2) The core components are arranged in the driven gear 30 provided in the input shaft 21 of 20).

Each component of the zero point adjustment means according to the invention are arranged in a plurality of mounting plates 15 are arranged in a layered structure connected to each other by a support column (15a),

The rotational motion of the output member 2 finally delivered to the potentiometer 20 passes through the power transmission means 1 composed of a series of reduction gear groups, and the two interlocking gears 10b engaged thereon. Delivered to the relay shaft 11 by 10c,

The input shaft 21 of the potentiometer 20 is pivoted through the driven gear 30 meshing with the relay gear 13 arranged on the relay shaft 11,

The forward / reverse turning degree of the input shaft 21 is soon converted into a resistance value (for example, 100 kΩ closed and 900 kΩ fully open), and eventually the valve opening is transmitted to the instrument panel (not shown) so that the field can be confirmed. do or,

The cable 23 is transmitted to an indicator (not shown) of the central control panel to allow remote confirmation.

Next, looking at the driven gear 30 and the elastic member 40 forming the core of the zero point adjusting means according to the present invention,

As shown in Figures 2, 3 and 4,

The elastic member 40 is arranged in the receiving portion 33 of the driven gear 30 to press the input shaft 21 of the potentiometer so that the rotational movement of the relay shaft 11 to the input shaft 21. To be delivered.

To this end, the cross-sectional area of the input shaft 21 is smaller than the end area of the shaft hole 31 of the driven gear 30,

The elastic member 40 may have a variety of types and sizes but in the present invention is bent to form a triangular leaf spring,

In particular, the outside of each vertex of the leaf spring 40 forming an equilateral triangle is in contact with the inner surface of the receiving portion 33 of the driven gear 30, the inside of the central portion of each side of the leaf spring 40 is the outer peripheral surface of the input shaft 21 It is made to be able to press the paper in contact with.

Since the leaf spring 40 is formed by bending a plate, both ends 43 are in contact with each other.

Particularly, a pair of elastic reinforcing bent portions 41 are formed on the upper and lower portions corresponding to each side of the triangle so as to be bent outwards, and thus the relay may be repeated even for a long time by the elasticity of the spring 40 without using a special material. It is possible to ensure that the reference zero position of the driven gear 30 and the potentiometer 20 engaged with the gear 13 does not change.

In addition, the elastic reinforcing bent portion 41 is when the [driven gear 30-elastic member 40-washer 45 assembly] to the input shaft 21 of the potentiometer 20

The imaginary circle passing through each bent portion located at three sides of the triangular leaf spring is larger than the outer diameter of the input shaft and serves as a shaft diameter guide for the input shaft, thereby ensuring easier mutual coupling.

Furthermore, since the elastic member 40 is built in the driven gear 30 receiving portion 33, the outer area is pushed out by the coupling with the input shaft 21 of the potentiometer, compared to the state where no external force is applied. This becomes larger (it is possible to expand the size more smoothly, especially since the leaf springs are not completely interconnected to form a closed circuit but have separate ends 43), so that the elastic member 40 and the driven gear 30 Will also be strong.

The departure prevention of the elastic member 40 located in the driven gear 30 receiving portion 33 can be made by various methods, but to improve productivity

A washer 45 mounting groove 35 is formed outside the receiving portion 33 of the driven gear 30,

Separation prevention of the washer 45 arranged in the mounting groove 35 is made by a cocked (cocking) processing portion (35a) (eight in Fig. 3 [B]).

The zero adjustment means of the present invention as described above is necessary when adjusting the zero point during assembly or after repair

[Endless type (rotational gear 30-elastic member 40-washer 45 assembly) in the state coupled to the input shaft 21 of the potentiometer (20) without any specific direction If it is rotated by a certain angle, it is no longer possible to rotate, and on the contrary, it adopts a stopper type potentiometer that needs to rotate the input shaft 21.

The valve is placed in the open or closed position and the driven gear 30 engaged with the relay gear 13 provided on the relay shaft 11 connected to the output member 2 is fixed.

Insert a flat head screwdriver into the tool coupling groove 21a of the input shaft 21 of the potentiometer 20 and turn the input shaft into a slip type.

The initial assembly and zero adjustment can be easily, conveniently and quickly made by arranging at the maximum rotation point of the potentiometer, that is, zero point.

In addition, even when the opening and closing positions of the valves outside the limit position of the potentiometer in the conventional actuator operation, the power of the motor continues to be transmitted. Therefore, the endless type was adopted to prevent the potentiometer from being damaged.

In the present invention, even if the stopper type potentiometer is adopted for convenience of zero adjustment, when the power of the motor is continuously transmitted beyond the limit position of the potentiometer, the input shaft of the elastic member 40 and the potentiometer ( Since the slippage occurs due to the slippage of the coupling force between the 21), the potentiometer breakage prevention function is achieved.

Therefore, the concept of 'slip' in the present invention can be referred to as a reference to the zero control and damage prevention method.

As described above, the present invention uses the transistor (that is, the third switching element) as a single electronic component to protect the propagation delay (i.e., the time when the short circuit current or overcurrent flows to the power device IGBT to start the protection operation). Minimized the risk of breakage of IGBTs,

In a three-phase motor, at least six IGBTs and six IGBT drive circuits for each IGBT are required. In the present invention, a single component transistor is used as a protection part, and a zener diode, which is a single component, is used to stabilize the driving voltage input to the IGBT. The overall circuit configuration has been simplified, such as the use of the motor, which greatly reduces the cost of the motor control circuit.

In addition, the slip type zero point adjusting means of the present invention is an elastic member capable of pressing the input shaft on the driven gear provided on the input shaft of the potentiometer (particularly, stopper type) connected to the relay shaft connected to the power transmission means. In particular, the elastic member is composed of a triangular leaf spring, implements a structure for preventing elastic reinforcement and detachment, and by forming a tool coupling groove at the input shaft end of the potentiometer Convenience can be improved.

In the above description of the present invention, a motor speed control type electric actuator using an IGBT having a specific shape and structure has been described with reference to the accompanying drawings. However, the present invention may be variously modified and changed by those skilled in the art. Should be construed as falling within the protection scope of the present invention.

Claims (7)

delete delete delete delete delete An electric actuator comprising a motor as a driving source, an output member connected to the valve to open and close the valve, a power transmission member to transmit the power of the motor to the output member, and a motor control circuit to control the operation of the motor. To The motor control circuit includes a microcomputer for outputting a control signal; An IGBT for adjusting a driving speed of the motor; Receiving an PWM signal from the microcomputer and driving the IGBT according to the received PWM signal; The IGBT driving circuit unit receives a PWM signal from the microcomputer and a receiving unit; A driving unit connected to the gate terminal of the IGBT, each of which includes a first switching element and a second switching element which are turned on / off in opposition to each other by an output signal of the receiver to drive the IGBT; When the base end is connected to the collector end of the IGBT, and the collector end is connected to the base end of the first switching device so that a current larger than a reference value flows through the IGBT, the base is turned on to maintain the turn-off state of the first switching device. A third switching device for preventing damage to the IGBT, a base end is connected to the receiving unit, and a collector end is connected to a base end of the third switching device, and is turned on when the third switching device is turned on; It comprises a protection unit including a fourth switching element for preventing the malfunction of the switching element, A zener diode for constantly regulating the magnitude of the driving signal input to the gate end of the IGBT is connected to the base end of the first switching element in parallel. The receiver is a photocoupler comprising a photodiode receiving a PWM signal from the microcomputer and a phototransistor turned on / off by the photodiode, A capacitor is connected between the receiver and the driver to reduce a delay time at which the output signal of the receiver is transmitted to the driver. A relay shaft connected to the output member and having a relay gear; An input shaft connected to the potentiometer; A driven gear having a shaft hole having a cross-sectional area larger than that of the input shaft, and a receiving portion formed around the shaft hole, the driven gear meshing with the relay gear of the relay shaft; And And an elastic member arranged at a receiving portion of the driven gear to press the input shaft so that the rotational movement of the relay shaft is transmitted to the input shaft. The elastic member is a triangular leaf spring having an elastic reinforcement bent portion, A tool coupling groove is formed at the end of the input shaft, The potentiometer is a motor speed control type electric actuator using an IGBT, characterized in that the stopper type (stopper type). The method of claim 6, The driven gear receiving portion is provided with a mounting groove for mounting a washer to prevent separation of the elastic member, A motor speed control type electric actuator using an IGBT, wherein the mounting groove is formed with a caulking part to prevent the washer from being separated.

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