JP6070595B2 - Electric valve drive - Google Patents

Description

  The present invention relates to a motor-driven valve driving device that drives various valves by a motor, and more particularly to a technique for facilitating measurement of insulation resistance of a motor winding during maintenance inspection.

  Many electric valve drive units are used in thermal power plants, etc., and these motorized valve drive units perform periodic inspections at predetermined intervals according to the importance of the valves to be driven, and reliability during plant operation We are trying to secure it. When inspecting these motor-driven valve drive devices, it is necessary to measure the insulation resistance of the motor winding in order to grasp and manage the reduction in insulation of the motor winding due to aging.

  In the conventional electric valve driving device, as schematically shown in FIG. 4, the power supply cable to the motor is connected to an external terminal block via an electromagnetic switch. In such an electric valve drive device, when measuring the motor winding resistance, either remove the motor winding terminal from the electromagnetic switch or open the electromagnetic switch to reduce the resistance between the motor winding terminal and the ground terminal. It is necessary to measure.

  However, the electromagnetic switch is not provided in the terminal block storage part that is easily accessible by the measurer, but is provided in the electrical / electronic component storage part having a sealed structure together with the control circuit board. Therefore, when measuring the insulation resistance of the motor winding, it is necessary to disassemble a part of the motor-operated valve driving device so that the measurer can access the electromagnetic switch.

  Such disassembly of the motor-driven valve drive device requires extra time for disassembly and reassembly, and has a problem in terms of inspection time and inspection cost. In addition, disassembling the motor-driven valve drive device, although partly, may cause fine dust or moisture to enter the interior of the electrical / electronic component storage unit where electrical / electronic components are stored in places where the installation environment is not good. It has also become a cause of impairing the operation reliability of the drive unit over a long period of time.

  Although not related to the motor-operated valve driving device, when measuring the ground insulation resistance of the motor winding, there is known a technique for automatically measuring the insulation resistance by connecting a measurement line to the motor connection side of the electromagnetic switch. (Patent Document 1). Further, an electromagnetic switch provided with a lead wire for measuring insulation resistance from the motor connection side of the electromagnetic switch is known (Patent Document 2).

JP-A-6-43195 JP 2010-160124 A

  There are many places where the motor-operated valve driving device is not necessarily in a good working environment, such as a high place, an underground space, or a narrow place where piping intersects in a complicated manner. Nevertheless, inspection work is required to be performed safely and reliably. Moreover, even if it is a motor-driven valve drive device installed in a place where the working environment is good, the number of motor-driven valve drive devices installed per plant is large, and it is required to perform inspection work in the shortest possible time.

  However, in the conventional electric valve driving device described above, the operator measured the insulation resistance of the motor winding after disassembling a part of the electric valve driving device so as to approach the electromagnetic switch. I was spending extra time. Furthermore, there is a risk that fine dust or moisture may enter the motor-driven valve driving device.

  Therefore, the present invention eliminates the work of disassembling a part of the motor-operated valve driving device in order to approach the electromagnetic switch in measuring the insulation resistance of the motor winding of the motor-operated valve driving device, and can be safely performed in a short time. It is another object of the present invention to provide a motor-driven valve driving device that can reliably measure insulation resistance.

The invention according to claim 1 is an electric valve driving device that drives a valve by a motor via a gear train, a mechanism component housing portion that houses the gear train and a sensor, and a control circuit board to which the sensor is connected. An apparatus main body having an electric / electronic component storage unit for storing the electric terminal and a terminal block storage unit for storing an external terminal block to which the electric / electronic component is connected, and controlling electric power to the motor in the electric / electronic component storage unit Provided with an electromagnetic switch, one end of the insulation resistance measurement wiring is connected to the motor connection side of the electromagnetic switch, and the other end of the insulation resistance measurement wiring is provided in the terminal block housing for dedicated insulation resistance measurement Connected to a terminal block, the insulation resistance measuring terminal block is formed by integrally molding a conductive metal fitting made of a conductive material on a terminal block plate made of an insulating material, and provided with a small diameter or large diameter step on the outer periphery of the conductive metal fitting, The guide Fitting a both ends screwing format, to project on both sides of the terminal block plate disposed, electrically operated valve, characterized in that the measurable insulation resistance of the motor from the terminal block housing unit side It is a drive device.

  According to a second aspect of the present invention, there is provided the electric valve driving device according to the first aspect of the present invention, wherein a sealing structure is provided between the mechanical component storage portion and the terminal block storage portion.

  According to the first aspect of the present invention, in the measurement of the insulation resistance of the motor winding of the electric valve driving device, it is not necessary to disassemble a part of the electric valve driving device in order for the measurer to approach the electromagnetic switch. Insulation resistance can be measured safely and reliably in a short time.

  According to the second aspect of the present invention, since the space between the mechanical component storage portion and the terminal block storage portion is a sealed structure, fine dust is contained inside the mechanical component storage portion in which the encoder and the thrust sensor are stored. There is no danger of moisture entering. Therefore, the operation reliability of the electric valve drive device can be ensured for a long period of time.

According to the present invention , since the insulation resistance measuring terminal block is formed by integrally molding the conductive metal fitting made of the conductive material on the terminal block board made of the insulating material, the terminal block plate and the conductive metal fitting can be brought into close contact with each other, A highly reliable explosion-proof structure can be realized.

According to the present invention , even when an external force is applied in the longitudinal direction of the conductive metal fitting, it is possible to prevent the conductive metal fitting from dropping from the terminal block plate.

According to the present invention , the conductive metal fittings are screwed at both ends, and are disposed so as to protrude on both the front and back sides of the terminal base plate, so that the space in the thickness direction around the terminal base plate can be reduced. As a result, the electric valve drive device can be collected in a compact outer dimension.

1 is a partial cross-sectional view showing a schematic configuration of an electric valve driving device according to the present invention. It is a terminal block wiring diagram for insulation resistance measurement of an electric valve driving device showing an embodiment of the present invention. It is sectional drawing of the terminal block board which shows the AA arrow in FIG. It is an external terminal block wiring diagram of the motor-driven valve drive device by a prior art example.

  An electric valve driving device 1 according to the present invention will be described with reference to the drawings. As shown in FIG. 1, the motor 2 is attached to the side surface of the apparatus main body 3 with the motor 2 in the attitude | position orthogonal to a valve stem (illustration omitted). In many cases, a three-phase induction motor having excellent reliability such as durability is used for the motor 2.

  The mechanical component storage section 4 of the apparatus main body 3 includes a worm shaft 5 connected to a motor shaft, a worm wheel 6 that meshes with the worm shaft 5, and a thrust unit that converts the rotation of the worm wheel 6 into a reciprocating operation of the valve stem. 7 is stored. Therefore, the valve stem can be reciprocated by the rotation of the motor shaft.

  The mechanical component storage 4 is provided with an encoder 8 for detecting the amount of movement of the valve stem from the amount of rotation of the worm wheel 6 and a thrust sensor 9 for detecting thrust acting on the worm shaft 5. The thrust sensor 9 directly detects thrust acting on the worm shaft 5, but the thrust of the worm shaft 5 corresponds to the rotational torque of the worm wheel 6 meshing with the worm shaft 5. It is used as load information that affects

  Further, the apparatus body 3 is provided with a manual handle 11 for manually operating the valve and a clutch mechanism 12 for switching from electric operation to manual operation.

  On the opposite side surface of the apparatus main body 3 to which the motor 2 is attached, an electrical / electronic component storage section 14 for storing the control circuit board 13 and the like is provided. In the embodiment shown in FIG. 1, the mechanical component storage unit 4 and the electrical / electronic component storage unit 14 are configured as one component, but they may be configured as separate components.

  In addition to the control circuit board 13 on which the CPU is mounted, the electrical / electronic component storage section 14 stores a DC power supply as a control power supply and an electromagnetic switch 15 for opening and closing the power supply to the motor 2. Depending on the specifications, an inverter device that variably controls the rotation speed of the motor 2 may be housed. The control circuit board 13 is connected to the encoder 8 and the thrust sensor 9 described above, and is input as position information of the valve stem and load information acting on the valve stem.

  An operation box 16 is attached to the opening of the electric / electronic component storage section 14, and a switch 17 for operating the motor-operated valve driving device 1 in the local mode is provided on the outer surface of the operation box 16. Further, an opening degree indicator 18 for displaying the opening degree of the valve or a lamp indicating the fully opened / closed state of the valve is provided. These switch 17, opening indicator 18, lamp and the like are connected to the control circuit board 13 and used as input / output signals.

  The operation box 16 is attached to the opening of the electrical / electronic component storage unit 14 in a sealed structure. Further, the operation box 16, the switch 17, and the opening indicator 18 are also attached in a sealed structure. For example, as the rotary switch, a sealing structure is realized by using a magnetic sensing type that does not require the switch shaft to penetrate the operation box 16.

  In addition to the aforementioned input / output signals, the control circuit board 13 can be connected to a remote input signal for operating the motor-operated valve driving device 1 in the remote mode. The control circuit board 13 on which the CPU is mounted generates a fully open or fully closed state as valve opening information as a relay output signal and can be transmitted to the outside such as a central control room. These remote input signals and relay output signals are connected to the outside from the control circuit board 13 via the external terminal block 21 provided in the terminal block storage section 19.

  The electromagnetic switch 15 is a general-purpose component for opening and closing the power supply to the motor 2, and controls the power supply to the motor 2 by a control signal from the control circuit board 13. The output side of the electromagnetic switch 15 is connected to the motor winding 22, and the input side is connected to the external terminal block 21. Such a configuration is the same as that of a conventional electric valve driving device. However, in the present invention, as shown in FIG. 2, in addition to the configuration of the prior art, one end 23a of the insulation resistance measurement wiring 23 is connected to the motor connection side of the electromagnetic switch 15, and the insulation resistance measurement wiring 23 The other end 23 b is connected to an insulation resistance measurement terminal block 24 provided in the terminal block storage section 19.

  The insulation resistance measurement terminal block 24 is a dedicated terminal block provided for measuring the ground insulation resistance of the motor winding 22. As shown in FIG. 3, the insulation resistance measuring terminal block 24 is formed integrally with the terminal block plate 25 in the same manner as the external terminal block 21. Specifically, conductive fittings 26, 27, and 28 made of a conductive material such as a copper alloy are integrally formed on a terminal base plate 25 made of an insulating material such as a synthetic resin.

  The terminal block plate 25 is attached to the back of the terminal block storage portion 19 forming a part of the apparatus body 3 using a sealing member such as an O-ring 29. The terminal block 25 has an airtight and liquid-tight structure with the conductive metal fittings 26 and 27 constituting the external terminal block 21 and the conductive metal fitting 28 constituting the insulation resistance measuring terminal block 24. Specifically, when the terminal board 25 is molded from a synthetic resin material, the above-described conductive fittings 26, 27, 28 are inserted and molded.

  Signal lines and power lines connected to the external terminal block 21 and the insulation resistance measuring terminal block 24 are connected to the outside via the conduit connection hole 31 provided in the lower part of the terminal block storage unit 19.

  The opening of the terminal block storage part 19 has an airtight and liquid-tight structure by a sealing member such as an O-ring 32 and a storage part lid 33, and the terminal block storage part 19 can also cope with an explosion-proof specification. Here, even if the storage cover 23 is removed from the opening of the terminal block storage part 19 and the terminal block storage part 19 is opened, the terminal block plate 25 is attached to the apparatus body 3 with a sealing structure. Therefore, it is possible to prevent fine dust and moisture from entering the mechanical component storage unit 4 and the electrical / electronic component storage unit 14.

  Steps 34 and 35 having a small diameter or a large diameter are provided on the outer periphery of the conductive metal fitting 28 constituting the terminal block 24 for measuring the insulation resistance. Specifically, a small-diameter step 34 is provided at both ends of the round shaft-shaped conductive fitting 28, and a plurality of small-diameter steps 35 are also provided at the middle portion of the round shaft. As a result, when the terminal base plate 25 is integrally molded with the synthetic resin material, the synthetic resin material also flows into the small-diameter portion of the conductive metal fitting 28, and the conductive metal fitting 28 firmly adheres to the terminal base plate 25 to ensure a reliable airtight liquid. A dense structure can be realized. In addition, by providing steps 34 and 35 having a small diameter or a large diameter on the outer periphery of the conductive metal fitting 28, it is possible to prevent the conductive metal fitting 28 from falling off the terminal base plate 25 even when an external force is applied to the conductive metal fitting 28 in the axial direction.

  The conductive metal fitting 28 constituting the insulation resistance measurement terminal block 24 is formed by screwing both ends of the round shaft on the front and back sides of the terminal block plate 25 by an equal amount. By arranging the conductive metal fittings 28 so as to project the same amount on both the front and back sides of the terminal block plate 25, the space in the thickness direction around the terminal block plate can be reduced. Even if the shaft diameter of the conductive metal fitting 28 is increased, the terminal metal plate 25 can be mounted by utilizing the space on the mechanical component storage section 4 side by projecting the conductive metal fitting 28 on both the front and back sides of the terminal base plate 25. It is possible to reduce the protruding amount of the conductive metal fitting 28 toward the terminal block housing part 19 side of the base plate 25. As a result, the electric valve drive device 1 can be summarized in a compact outer dimension.

  Next, a procedure for measuring the ground insulation resistance of the motor winding 22 in the electric valve driving device 1 according to the present invention will be described.

  First, it is confirmed in the central control room or the like that the power to the motor 2 that is the main power source is off, and the main power source is also confirmed in the field display or the like. Thereafter, the storage portion lid 33 is removed from the opening of the terminal block storage portion 19. The preparation is now complete, and you can move on to insulation resistance measurement.

  After confirming that the electromagnetic switch 15 is open in the external terminal block 21, place the insulation resistance measuring instrument probe between the ground terminal 36 of the external terminal block 21 and each terminal of the insulation resistance measuring terminal block 24. Touch the to read the resistance value. This work is sufficient and no other work is required. That is, in the work of measuring the insulation resistance of the motor winding 22, the mechanical component storage unit 4 and the electrical / electronic component storage unit 14 remain sealed, and there is no risk of fine dust or moisture entering the inside of the apparatus body 3. . Insulation resistance can be measured safely and in a short time. After completion of the measurement, the storage section lid 33 is attached to the opening of the terminal block storage section 19, and all operations are completed.

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the Example mentioned above, A various deformation | transformation implementation can be performed. For example, in the above-described embodiment, the insulation resistance measuring terminal block 24 and the external terminal block 21 are separately configured, but these terminal blocks may be integrally formed. In the embodiment, a three-phase induction motor is used. However, the drive motor is not limited to a three-phase induction motor, and can be applied to a single-phase motor or a DC motor. Furthermore, in the embodiment, the encoder 8 is used to detect the movement amount of the valve stem, but a mechanical limit switch or an electromagnetic detector may be used instead of the encoder. In the embodiment, the thrust sensor 9 is used to detect the thrust acting on the worm shaft 5, but a mechanical detector using a disc spring or the like may be used instead of the thrust sensor.

  The motor-operated valve driving apparatus according to the present invention can contribute to ensuring the operation reliability of the plant because the ground insulation resistance of the motor winding can be measured safely and in a short time.

DESCRIPTION OF SYMBOLS 1 Electric valve drive device 2 Motor 3 Device main body 4 Mechanical component storage part 9 Thrust sensor
13 Control circuit board
14 Electrical and electronic parts storage
15 Electromagnetic switch
19 Terminal block storage
21 External terminal block
23 Insulation resistance measurement wiring
24 Terminal block for measuring insulation resistance

Claims (2)

An electric valve driving device for driving a valve by a motor via a gear train, a mechanical component housing portion for housing the gear train and a sensor, and an electric / electronic component housing portion for housing a control circuit board to which the sensor is connected And an apparatus main body having an external terminal block to which an electric / electronic component is connected, and an electromagnetic switch for controlling electric power to the motor is provided in the electric / electronic component storage portion and the electromagnetic One end of the insulation resistance measurement wiring is connected to the motor connection side of the switch, and the other end of the insulation resistance measurement wiring is connected to a dedicated insulation resistance measurement terminal block provided in the terminal block housing portion, and the insulation The resistance measurement terminal block is formed by integrally molding a conductive metal fitting made of a conductive material on a terminal block board made of an insulating material, and a step having a small diameter or a large diameter is provided on the outer periphery of the conductive metal fitting. A formula, to project on both sides of the terminal block plate disposed electric valve driving apparatus is characterized in that the measurable insulation resistance of the motor from the terminal block housing unit side.   The motor-driven valve driving device according to claim 1, wherein a sealing structure is provided between the mechanical component storage portion and the terminal block storage portion.

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