JP6285523B2 - Electric valve actuator, emergency shutoff valve / emergency release valve, and valve electric actuator abnormality diagnosis method - Google Patents

Description

The present invention relates to an electric valve actuator, an emergency shut-off valve / emergency open valve , and an abnormality diagnosis method for an electric valve actuator , and is particularly mounted on a rotary valve such as a ball valve or a butterfly valve. The present invention relates to an electric actuator for a valve that is fully opened.

  Conventionally, an electric valve is used in a piping system for flowing a fluid such as water or chemicals, and the flow of the fluid is controlled by opening and closing the valve by remote operation. In such a piping system, in the event of an emergency such as a power outage, an earthquake, or a fire, it is necessary to quickly bring the pipe line into a fully closed state or a fully open state.

  At present, mechanical spring types and secondary power supply drive types are known as types of emergency electric actuators used for valves for making a pipeline fully closed or fully open in an emergency.

  A mechanical spring type electric actuator is equipped with a spring on the drive shaft of the electric actuator, and when the valve body is rotated, the spring is wound up so as to store a restoring force that rotates the valve body in the opposite direction. When shut off, the drive shaft is rotated by the energy of the restoring force stored in the spring by winding up, so that the valve is fully closed or fully opened.

  The secondary power drive type electric actuator is equipped with a DC motor and a secondary power supply.When AC power is supplied, the AC power is converted to DC and the motor is driven to bring the valve body to a predetermined opening. When the AC power supply is interrupted by a power failure, the motor is driven by a secondary power supply that is a direct current, and the valve is fully closed or fully opened.

  Since the mechanical spring type electric actuator winds up the spring at the same time as rotating the valve body, a load for rotating the valve body and a load for winding the spring act simultaneously on the motor. For this reason, a large motor with a large torque is required, and there is a drawback in that the actuator is increased in size and weight.

  On the other hand, the secondary power source drive type electric actuator does not have the disadvantages of the mechanical spring type electric actuator, and in recent years, as a secondary power source, the electric double layer capacitor is less deteriorated and has a longer life than the conventional secondary battery. Has come to be used.

  When an emergency electric actuator is used with an emergency shut-off valve, the valve is always kept fully open or at an intermediate opening, and an external power source or secondary power supply is used in an emergency (when a power failure, earthquake, fire, etc. occurs) The direct current motor is driven by the battery, and the valve is forcibly fully closed. On the other hand, when used as an emergency release valve, the valve is always maintained in a fully closed state, and a valve that drives a DC motor by an external power source or a secondary battery is forcibly fully opened in an emergency. In this way, the emergency shut-off (open) valve is kept fully open or fully closed for a long period of time, and even if a periodic check of the valve is carried out, there is no opportunity to operate the valve only once a year. Is normal.

  Usually, when an electric double layer capacitor is used as a secondary power source for an emergency electric actuator, a DC brush motor is often used as a drive source for the electric actuator in terms of cost. When an electric actuator using a DC brush motor is stopped for a long time, the commutator of the rectifier (brush and commutator) part of the motor is made of copper-based metal. Oxidizes and increases the contact resistance with the brush, and a contact failure that prevents current from flowing through the armature (armature coil) of the motor may occur, resulting in inoperability during startup.

  Not only the rectifier part of the DC brush motor but also the limit switch that determines the open / close position of the electric actuator, if the actuator is stopped for a long time, the contact surface will oxidize and the contact resistance will increase. Operation may occur.

  In addition, the actuator may become inoperable due to the seizure or sticking of the shaft due to the outflow or depletion of lubricating oil from the actuator output shaft, gear bearing and DC motor bearing due to the actuator being stopped for a long time. There is also. Furthermore, a grease lubricating oil film may be cut off in the reduction gear portion of the actuator, deterioration due to moisture mixing, etc., and inoperability due to gear seizure may occur.

  If the valve is left fully open and fully closed for a long time, sludge and other deposits accumulate on the ball seats and discs, causing sticking to the valve part and sticking to the stem part. Inoperability may occur. This failure can occur not only in secondary power drive type electric actuators but also in mechanical spring type electric actuators that are considered to be highly reliable because the valve body can be rotated in an emergency with a simple mechanism The possibility of becoming inoperable in an emergency cannot be excluded.

  When an electric emergency actuator using an electric double layer capacitor as a secondary power source is in a stopped state for a long time, even if it is an electric double layer capacitor that is less deteriorated and has a longer life than a conventional storage battery, the capacity due to the deterioration The power supply necessary for operating the valve during an emergency operation cannot be supplied, and there is a possibility that the device may become inoperable.

  The emergency shut-off (opening) valve is required to operate reliably in the event of an emergency that cannot be predicted in advance and suddenly occurs. Therefore, the valve function including the emergency electric actuator is always maintained normally. It is necessary to maintain the power supply capability of the electric double layer capacitor, which is a secondary power source that supplies power to the motor, and to prevent inoperability during an emergency operation.

  Patent document 1 is proposed as an example of this prevention measure. In Patent Document 1, when the valve is not used for a long period of time, the packing at the water stop portion of the flow control valve is fastened to the valve shaft, or the flow adjustment valve and the main body are entangled with each other due to water pressure. In order to prevent this, the timer means for outputting a signal every time a fixed time elapses after the flow regulating valve is closed, the first closing position detecting means and the second closing position detecting means for the flow regulating valve based on the signal from the timer means. The flow rate control apparatus provided with the control means which drives between is described.

  Further, in Patent Document 2, a discharge resistor is connected to a fully charged electric double layer capacitor, the terminal resistance of the electric double layer capacitor is measured after connecting the discharge resistor for a predetermined time, and the measured terminal voltage and Diagnostic method of electric double layer capacitor for determining life by comparing with remaining voltage after elapse of predetermined time in discharge characteristics as reference for life judgment of discharge resistance of fully charged electric double layer capacitor An emergency shut-off valve equipped with a deterioration detection device using the above is described.

Japanese Patent Laid-Open No. 8-100844 JP 2006-173385 A

  However, the flow control device described in Patent Document 1 does not operate for a long period of time, so that the seal of the water stop portion of the flow control valve is fastened to the valve shaft of the flow control valve, or the flow control valve and the main body by water pressure. Can prevent the flow control valve from becoming entangled, but the flow control device becomes inoperable by knowing in advance the water deterioration part of the flow control valve and the internal state of the flow control valve drive means By taking measures according to the deterioration situation before, it is impossible to avoid a situation in which the device becomes inoperable.

  In the emergency shut-off valve equipped with the diagnostic method of the electric double layer capacitor and the deterioration detecting device using the method described in Patent Document 2, for example, the diagnostic switch is operated at the time of periodic inspection to check the deterioration state of the electric double layer capacitor. Diagnosis can be made, but the deterioration status of the electric double layer capacitor cannot be grasped unless it is inspected and inspected, so if the deterioration of the electric double layer capacitor progresses between inspections and inspections, the electric double layer capacitor There is a possibility that the valve cannot be exchanged with a non-defective product by grasping the decrease in the power supply capability of the capacitor, and the valve cannot be urgently shut off (opened) in an emergency.

The present invention has been developed in order to solve the above-described problems. The object of the present invention is to periodically and automatically restore the reliability of the electric actuator and the valve on which the actuator is mounted, and the actuator. If a failure occurs in the built-in secondary battery and the mounted valve, maintenance can be performed to eliminate the failure, so that the valve can be fully closed or fully opened in an emergency. An object of the present invention is to provide an electric valve actuator, an emergency shut-off valve / emergency release valve , and an abnormality diagnosis method for the valve electric actuator .

In order to achieve the above object, an invention according to claim 1 is an electric actuator for opening and closing a valve with a DC motor, wherein a power supply unit and a secondary power supply unit are connected to the DC motor via the control unit, and the control unit Is the power charged in the secondary power supply unit at an angle within a range where no valve passage leakage occurs or a flow rate is satisfied when it is determined that the valve has not been opened or closed within a certain period of time. For a valve having a self-idling function for finely operating a DC motor using a motor and having a self-diagnosis function for diagnosing at least a commutator contact failure in the DC motor when no current is flowing in the DC motor during the fine-motion operation It is an electric actuator.

  According to a second aspect of the present invention, the valve is a butterfly valve or a ball valve, and the fine movement operation in the case of the butterfly valve is performed within an opening degree of 0 to 8% or an opening degree of 90 to 100%. This is an electric actuator for valves.

  The invention according to claim 3 is an emergency shutoff valve / emergency release valve equipped with an electric actuator for a valve.

  The invention according to claim 4 is an emergency shut-off valve / emergency release valve connected to the seismoscope.

The invention according to claim 5 is an electric actuator for opening and closing a valve with a DC motor, wherein the power supply unit and the secondary power supply unit are connected to the DC motor via the control unit, and the control unit is configured to operate the valve within a certain period. When it is determined that the opening / closing operation is not performed, the DC motor is finely moved using the power charged in the secondary power supply unit at an angle within a range where the valve passage leakage does not occur or within a range satisfying the flow rate. It has a self-idling function to be operated, and when a current does not flow through the DC motor at the time of fine movement operation, it is an abnormality diagnosis method for an electric actuator for a valve having a self-diagnosis function that diagnoses at least a commutator contact failure in the DC motor is there.

According to a sixth aspect of the present invention, the valve is a butterfly valve or a ball valve, and the fine movement operation in the case of the butterfly valve is performed within an opening degree of 0 to 8% or 90 to 100%. This is a method for diagnosing abnormalities in electric actuators for automobiles.

According to the first or fifth aspect of the present invention, when the current value flowing through the armature of the DC motor is an abnormal value when the actuator is finely operated, the DC motor bearing, the gear bearing, etc. are fixed, the gear grease is cutting, sticking of the valve stem, ball valve, it determined that sticking of disuccinimidyl, abnormality in the valve fitted with a mechanism portion or actuator of the electric actuator valve comprising a DC motor as biting or the like has occurred. As a result, if necessary maintenance or replacement of parts is performed , the malfunction of the actuator can be eliminated and the function of the actuator can be restored to a normal state. Reliability as a shutoff valve or emergency release valve can be restored and maintained. In addition, the self-idling function for determining the opening / closing operation of the valve within a certain period is exhibited, and this self-idling function can reliably operate as an emergency shut-off valve or an emergency release valve in an emergency. In addition, since it is possible to determine the presence or absence of a malfunction from the current value flowing through the armature of the DC motor and the measurement result of the charging status of the electric double layer capacitor, a necessary warning can be issued when a malfunction occurs, and an emergency shutdown is ensured in an emergency. It can be operated as a valve or an emergency release valve.

  According to the invention of claim 2, by setting the swing range of the disk-shaped disc of the butterfly valve within the range of the fine movement operation, the electric actuator for a valve with improved reliability is obtained in the same manner as the ball valve. be able to.

  According to the third aspect of the invention, it is possible to provide a highly accurate emergency shutoff valve / emergency release valve equipped with an electric actuator.

  According to the invention which concerns on Claim 4, the electric actuator for valves can be reliably operated as an emergency electric actuator by the forced input from the outside at the time of the occurrence of an earthquake.

According to the sixth aspect of the present invention, by setting the swing range of the disk-like disc of the butterfly valve within the range of the fine movement operation, the abnormality diagnosis can be performed while improving the reliability as with the ball valve.

It is a block diagram explaining the structure of the electric actuator for valves which concerns on this invention. It is a schematic diagram explaining the rocking | fluctuation condition of the ball valve body of a fully closed state. It is a schematic diagram explaining the rocking | fluctuation condition of the ball valve body of a full open state. It is a fragmentary sectional view showing the state where the electric actuator for valves concerning the present invention was mounted in the ball valve. (A) It is a schematic diagram which shows the condition in which the oxide film was formed on the surface of the commutator of DC motor. (B) It is a schematic diagram which shows the condition where the oxide film formed in the surface of the commutator of DC motor was removed by the friction with the brush by rocking | fluctuation rotation. It is a flowchart explaining operation | movement of a self-idling function and a self-diagnosis function. It is a figure which shows the charging / discharging characteristic of an electric double layer capacitor.

  Embodiments of an electric actuator for a valve according to the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a block diagram showing the configuration of an electric actuator for a valve according to the present invention. In the figure, 1 is an electric actuator for a valve, and 2 is a valve controlled by the electric actuator for valve.

  In FIG. 1, a valve electric actuator 1 includes an operation unit 3, a power supply unit 4, a secondary power supply unit 5, a control unit 6, a motor drive circuit 7, a DC motor (DC motor) 8, and a gear. A row 9, an output shaft 10, a position detector 11, and an alarm unit 12 are provided.

  The operation unit 3 is used to operate the electric actuator 1 for valves from the outside, and can appropriately select and operate the operation mode switching operation function, the forced operation input function, and the reset function depending on the operation purpose. it can.

  The operation unit 3 can select whether the valve 2 equipped with the valve actuator 1 is used as an emergency shut-off valve or an emergency release valve by the operation mode switching function. With this function, the valve 2 equipped with the electric actuator 1 for the valve can be easily used as an emergency shut-off valve or an emergency release valve according to the use location.

  The operation unit 3 can operate the electric actuator 1 for the valve by overriding the control of the control unit 6 by manual operation or by inputting a signal or the like from the seismoscope by a forced operation input function. With this function, the electric valve actuator 1 can be operated as an emergency electric actuator by forced input from the outside in an emergency other than the occurrence of a power failure, for example, in the event of an earthquake or a pipe damage accident.

  In addition, the operation unit 3 performs an operation mode switching operation on the operating state of the valve-operated electric actuator 1 that has been operated urgently after the valve 2 equipped with the valve-use electric actuator 1 has been operated as an emergency shut-off valve or an emergency release valve. It is possible to return to the normal operating state set by the function. With this function, the emergency operated valve 2 can be automatically returned to a normal operating state without troublesome manual operation.

  The power supply unit 4 includes an AC / DC conversion circuit for supplying operating electric power to the valve electric actuator 1, converts the external AC power source 13 into a direct current, and converts the secondary power source unit 5 and the control unit 6. To supply.

  The secondary power supply unit 5 is an electric double layer in which a secondary battery charging circuit and a plurality are connected in series in order to supply power to the control unit 6 at the time of a power failure of the external AC power supply 13 or a self-idling function described later A capacitor 14 is provided. The secondary battery charging circuit supplies the DC power supplied from the power supply unit 4 to the electric double layer capacitor 14 with a constant voltage and a constant current for charging.

  As shown in FIG. 4, since the electric double layer capacitor 14 is formed by connecting a plurality of electric double layer capacitors 14a in series, the output voltage can be increased. For this reason, since it can be connected to the DC motor 8 and driven without going through the booster circuit, the structure of the secondary power supply unit 5 can be simplified, and the manufacturing cost can be reduced.

  The control unit 6 is a part that controls the operation of the electric actuator 1 for the valve based on the operation in the operation unit 3. The power supply unit output monitoring function, power switching function, valve opening / closing control function, 2 It has a secondary charge control function, a self-idling function, and a self-diagnosis function.

  The control unit 6 constantly monitors the output voltage of the power supply unit 4 by the power supply unit monitoring function, and determines that a power failure has occurred in the external AC power source 13 when the output voltage decreases, and also provides a power switching function. By switching the power supply source for the control unit 6 from the power supply unit 4 to the secondary power source unit 5, the valve electric actuator 1 is operated according to the operation mode preset in the operation unit 3 by the valve opening / closing control function, and the valve 2 is fully opened. Set to the fully closed state. With these functions, the control and operation of the valve actuator 1 can be reliably continued even in an emergency where the supply of the external AC power supply 13 is stopped, and the valve 2 can be reliably closed or fully opened. Can be in a state.

  In addition, the control unit 6 charges the electric double layer capacitor 14 by supplying power from the power supply unit 4 after the DC motor 8 is operated and monitors the charging state by the secondary charge control function. Until the charging voltage of 14 reaches a predetermined voltage, selection of the operation mode input by the operation unit 3 or acceptance of the forced operation input is prohibited. With this function, the charging time of the electric double layer capacitor 14 can be accurately measured without being affected by the outside, and the deterioration state of the electric double layer capacitor 14 can be correctly grasped.

  Furthermore, the control unit 6 uses the self-idling function to periodically and automatically swing and rotate the DC motor 8 regardless of the occurrence of an emergency, so that the valve 2 does not leak and the maximum flow rate is not exceeded. The valve body of the valve 2 is swung within an angle range satisfying the above. With this function, the internal mechanism of the valve electric actuator 1 including the DC motor 8 is operated, so that it is possible to prevent the electrical contacts from being oxidized and to prevent the gear train 9 from running out of oil. The sticking of the valve body and the stem can be prevented, and the function as an emergency shutoff valve or an emergency release valve can be maintained. This self-idling function can be realized not only by the swing operation of the DC motor 8 by a secondary battery described later, but also by the swing operation of the DC motor 8 by a commercial power source supplied from the power supply unit 4.

  In addition to the above functions, the control unit 6 measures the current flowing through the DC motor 8 at the time of self-idling of the valve electric actuator 1 that is periodically performed by the self-diagnosis function, and when the current is not measured or an abnormal current value Is measured, it is diagnosed that an abnormality has occurred in the mechanical part of the valve electric actuator 1 including the DC motor 8 or the valve 2 to which the actuator is attached, and an abnormality occurrence signal is transmitted to the alarm part 12. . With this function, it is possible to quickly grasp a problem that has occurred in the valve electric actuator 1 and the valve 2 on which the actuator is mounted, and to perform necessary maintenance or replacement of a failed part.

  The motor drive circuit 7 receives an operation command of the DC motor 8 from the valve opening / closing control function of the control unit 6, and the power supply unit 4 or 2 so that the DC motor 8 rotates according to the operation mode preset by the operation unit 3. DC power supplied from the next power supply unit 5 is supplied to the DC motor 8.

  The DC motor 8 is driven by receiving DC power from the motor drive circuit 7 and transmits power to a gear train 9 directly connected to the rotating shaft of the motor.

  The gear train 9 transmits the power transmitted from the DC motor 8 to the output shaft 10 attached to the final stage gear while reducing the rotational speed and amplifying the torque. A stem 15 of the valve 2 is connected to the output shaft 10, and a valve body (not shown) is rotated to open and close the valve 2.

  The position detector 11 has a function of detecting the rotation angle of the output shaft 10 and controlling the opening degree of the valve 2, and is composed of an auxiliary limit switch (not shown) as well as a main limit switch (not shown). The main limit switch is a switch for stopping the valve body of the valve 2 in the fully open and fully closed position, and the auxiliary limit switch is a valve in a range where the passage leakage of the valve 2 does not occur or in a range satisfying the maximum flow rate. This is a switch for restricting the swing angle of the valve body within an angle at which no passage leakage occurs or an angle satisfying the maximum flow rate when the second valve body is swung. Note that other sensors may be used in place of the auxiliary limit switch, or the swing angle may be input to the control unit 6 in advance, and swing may be performed by this input angle.

  The main limit switch and the auxiliary limit switch are placed on the open side and the close side, respectively, and are turned on and off by four open / close cams 16 fixed to the output shaft 10. The main limit switch is wired in series with a circuit for supplying DC power to the DC motor 8, and is adjusted and mounted so that it operates in the fully open and fully closed positions of the valve 2 respectively, and the power to the DC motor 8 is directly supplied. By cutting, the rotation of the output shaft 10 of the valve actuator 1 is stopped at the fully open and fully closed positions of the valve body. When the auxiliary limit switch is used as an emergency open valve that is normally closed, the valve body swing angle α (valve flow path) is such that the valve 2 does not leak through on the fully closed side. If the valve is used as an emergency shut-off valve that is normally fully open, the maximum flow rate of the valve is satisfied on the fully open side. The valve body is mounted by adjusting the swing angle of the valve body (an angle range of 84 to 87 degrees starting from the center line of the valve flow path). The above swing angle is merely an example, and the swing angle of the valve body needs to be set according to the structure and nominal diameter of the valve. For example, in a floating ball valve having a nominal diameter of 3 / 8B to 10B, the angle is set in an angle range of 6 degrees to 15 degrees corresponding to the nominal diameter.

  FIG. 2 shows a schematic diagram when an auxiliary limit switch is mounted on the fully closed side in order to use the valve as an emergency release valve. The swing angle 18 of the ball valve body 17 viewed from the stem side is within a range in which the outer peripheral surface 20 of the ball valve body 17 and the entire circumference of the contact surface 22 of the ball seat 21 are in close contact with each other with the center line 19 of the valve channel interposed therebetween. Therefore, the flow path 24 of the ball valve body 17 is not opened, and fluid does not leak through the valve. In addition, the arrow in a figure shows the flow path direction of a valve | bulb.

  In the drawing, the valve body indicated by a solid line indicates the fully closed ball valve body 17 in which the flow path 24 of the ball valve body 17 is at a position orthogonal to the center line 19 of the valve flow path, and is indicated by a one-dot chain line. The valve body is a ball valve body 17 in a fully closed state in which the ball valve body 17 is swung clockwise to a swing angle + α (for example, +3 degrees) in the drawing, and the valve body indicated by a two-dot chain line is the ball valve body 17. The ball valve body 17 in a fully closed state that is swung counterclockwise in the drawing to a swing angle −α (for example, −3 degrees) is shown. In either case indicated by the solid line, indicated by the alternate long and short dash line, or indicated by the alternate long and two short dashes line, the swing angle of the ball valve element 17 is at least the outer peripheral surface 20 of the ball valve element 17 and the ball seat 21. In the present embodiment, the contact surface 22 may be limited to a range in close contact with each other. In the present embodiment, the solid line, the one-dot chain line, or the two-dot chain line represents either case. Even so, the outer peripheral surface 20 of the ball valve body 17 and the contact surface 22 of the ball seat 21 are in contact with each other over the entire width x of the contact surface 22. If the valve is in a fully closed state and does not cause passage leakage, the ball valve body 17 is in contact until the contact between the outer peripheral surface 20 of the ball valve body 17 and the contact surface 22 of the ball seat 21 is less than the width x. The swing angle may be increased.

  FIG. 3 shows a schematic diagram when an auxiliary limit switch is attached to the fully open side in order to use the valve as an emergency shutoff valve. The swing angle 25 of the ball valve body 17 viewed from the stem side coincides with a base line 26 (normally, the center line of the flow path 24 of the ball valve body 17 when the valve is closed). ), The outer peripheral surface 20 of the ball valve body 17 and the entire circumference of the contact surface 22 of the ball seat 21 are limited to a close range, and the area of the flow path 24 of the ball valve body 17 is not reduced. The maximum flow rate of the valve is maintained. In addition, the arrow in a figure shows the flow path direction of a valve | bulb.

  In the drawing, the valve body indicated by a solid line indicates the ball valve body 17 in a fully opened state where the flow path 24 of the ball valve body 17 is parallel to the center line 19 of the valve flow path, and is indicated by a dashed line. The valve body is a ball valve body 17 in a fully opened state in which the ball valve body 17 is swung clockwise to a swing angle + α (for example, +3 degrees) in the drawing, and the valve body indicated by a two-dot chain line is a ball valve body. The ball valve body 17 is shown in a fully opened state in which 17 is swung counterclockwise to a swing angle −α (for example, −3 degrees). When indicated by a solid line, when indicated by an alternate long and short dash line, or when indicated by an alternate long and two short dashes line, the swing angle of the ball valve element 17 is at least between the outer peripheral surface 20 of the ball valve element 17 and the ball seat 21. In the present embodiment, the contact surface 22 may be limited to the entire circumference of the contact surface 22. In the present embodiment, the solid line, the alternate long and short dashed line, and the alternate long and two short dashed line indicate any case. The outer peripheral surface 20 of the ball valve body 17 and the contact surface 22 of the ball seat 21 are in contact with each other over the entire width x of the contact surface 22. If the fully opened state of the valve is maintained and within the range satisfying the maximum flow rate of the valve, the ball valve body is maintained until the contact between the outer peripheral surface 20 of the ball valve body 17 and the contact surface 22 of the ball seat 21 falls below the width x. The swing angle of 17 may be increased.

  The alarm unit 12 displays the content of the failure when the occurrence of the failure is diagnosed by the self-diagnosis function of the control unit 6 and an abnormality occurs and a signal is transmitted. The alarm unit 12 is not necessarily provided as an independent function in the electric actuator 1 for valves. For example, a control signal is output from an interface circuit provided in the control unit 6 to separately display an alarm on an external device. It can also be done. When the valves of the piping are remotely operated all at once, it is more efficient to output the control signal from the interface circuit and display the contents of the trouble on the control room equipment.

  FIG. 4 is a partial cross-sectional view showing a state in which the valve electric actuator 1 according to the present invention is mounted on the ball valve 26. In this figure, the operation unit 3, the power supply unit 4, the secondary power supply unit 5, the control unit 6, and the like are housed in a housing 28 separate from the housing 27 housing the DC motor 8, the gear train 9, and the like. Although attached to the side surface of the casing 27, the embodiment of the electric actuator for valves according to the present invention is not limited to such a form, and the operation unit 3, the power supply unit 4, and the secondary power supply unit 5. Of course, there is no problem even if the control unit 6 and the like are housed in the same casing together with the DC motor 8 and the gear train 9 and the like.

  Next, the case where the valve electric actuator 1 according to the present invention is mounted on a ball valve and operated as an emergency shutoff valve or an emergency release valve will be described. After the external AC power supply 13 is connected to the electric conduit 29 of the valve electric actuator 1, the operation mode switching function of the operation unit 3 is used to change the operation mode of the valve electric actuator 1 to an emergency shut-off valve or emergency open. Select whether to use a valve.

  When the external AC power supply 13 is supplied, the secondary power supply unit 5 supplies the secondary DC power of the AC / DC conversion circuit of the power supply unit to the electric double layer capacitor at a constant voltage and constant current in the secondary battery charging circuit. 14 is charged. The control unit 6 monitors the charging voltage of the electric double layer capacitor 14 and selects or enforces the operation mode input by the operation unit 3 until the charging voltage of the electric double layer capacitor 14 reaches a predetermined voltage. The acceptance of the operation input is prohibited, and the stop state of the valve electric actuator 1 is maintained. In addition, the control unit 6 measures the charging voltage and charging time of the electric double layer capacitor 14 by the self-diagnosis function, and when charging to the predetermined charging voltage is not completed within the predetermined time, the control unit 6 Judges a problem and issues an alarm signal.

  When the charging of the electric double layer capacitor 14 is completed, the control unit 6 reads and determines the operation mode signal set by the operation unit 3 and gives an operation command for the DC motor 8 to the motor drive circuit 7. As a result, the DC motor 8 is supplied with the motor drive circuit 7 from the direct-current power rotating in the direction according to the operation mode, and stops when the valve body of the valve 2 is fully opened or fully closed. Maintain this state as.

  When a power failure occurs while being used as an emergency shut-off valve or an emergency release valve, control is performed in the following order within the control unit 6. The power supply unit output monitoring function that constantly monitors the output voltage of the power supply unit 4 determines that a power failure has occurred in the external AC power supply 13 at the same time that the output voltage decreases. The power supply switching function that receives a power failure occurrence signal from the power supply unit output monitoring function switches the power supply that supplies power to the control unit 6 from the power supply unit 4 to the secondary power supply unit 5. Next, the valve opening / closing function instructs the motor drive circuit 7 to supply the DC motor 8 with DC power that rotates in a direction for opening / closing the valve 2 in accordance with the operation mode preset by the operation unit 3. According to the set operation mode, the valve body rotates to a position that functions as an emergency shut-off valve or an emergency release valve and stops.

  In addition, the same control as described above can be performed when a signal input from an external seismic device due to the occurrence of an earthquake or a forced input of an operator due to piping breakage is input by a forced operation input function of the operation unit 3. This is performed by the control unit 6, and the valve body of the valve 2 rotates and stops at a position that functions as an emergency shut-off valve or an emergency release valve according to the set operation mode.

  When the power failure of the external AC power supply 13 is restored, the electric double layer capacitor 14 of the secondary power supply unit 5 is automatically charged, so that the operation unit 3 resets after the electric double layer capacitor 14 is fully charged. The normal operation mode can be restored by inputting a signal.

  The emergency shut-off valve and the emergency release valve are actuated in an emergency, and do not operate in normal conditions. Even if the operation is checked during regular inspection of the valve, it operates once a year. The degree is at best. If the emergency shut-off valve and the emergency release valve are not operated for a long period of time, as shown in FIG. 5A, contact failure due to the formation of an oxide film 32 on the surface 31 of the commutator 30 of the DC motor 8 on the actuator side, Occurrence of running out of oil in the motor bearing and gear train may cause phenomena such as sticking of the stem of the valve on the valve side and increase in stem torque due to sludge accumulation between the ball in contact with the ball and the ball seat. Can be considered. For this reason, there is a possibility that it cannot be fully opened or fully closed due to malfunction in an emergency, but an emergency shutoff valve or emergency release valve must operate reliably in an emergency for its intended purpose and does not operate In some cases, the surrounding area may be damaged greatly.

  In the electric actuator for valves according to the present invention, the controller 6 is provided with a self-idling function and a self-diagnosis function in order to reliably operate as an emergency shut-off valve or an emergency open valve in an emergency, and is reliable as an emergency shut-off valve or an emergency open valve. Maintaining and recovering sex. When the control unit 6 determines that the valve has not been opened / closed within a certain period of time (for example, within the past month) by the built-in stop count timer by the self-idling function, the passage leak of the valve is detected. The valve body is swung at an angle within a range where no generation occurs or within a range where the maximum flow rate is satisfied. In addition, the control unit 6 measures the current value flowing through the armature of the DC motor and the charging state of the electric double layer capacitor during self-idling by the self-diagnosis function, and determines the presence or absence of a defect based on the measurement result, If a defect is found, a necessary warning is issued.

  The operation of the self-idling function and the self-diagnosis function of the valve electric actuator 1 will be described below with reference to FIG. First, the stop count timer of the control unit 6 is reset when the operator inputs from the operation unit 3 using the operation mode switching operation function or the reset function (step S01).

  After the stop count timer is reset, the use time is measured by the stop count timer (step S02). When it is determined that the stop count timer is stopped for a certain period, for example, one month (step S03), the power supply of the control unit 6 is turned on. The power supply source to the control unit 6 is switched from the power supply unit 4 to the secondary power source unit 5 by the switching function, and the electric double layer capacitor 14 is connected to the DC motor 8 (step S04). Is swung (step S05).

  Although the angle at which the valve body swings in the swing operation of the DC motor 8 is slight, the reduction ratio of the gear train 9 is large, so the DC motor 8 rotates sufficiently. In the valve electric actuator 1 of the present embodiment, the reduction ratio of the gear train 9 is 1348: 1, and the number of rotations of the DC motor 8 required to rotate the output shaft 10 by 3 degrees is 11.2. For this reason, even if the DC motor 8 is swung and rotated by the amount by which the output shaft 10 is finely moved about 3 degrees, the brush 33 of the DC motor 8 and the surface 31 of the commutator 30 are sufficiently rubbed, and the commutator is caused by the friction at that time. Since the surface 31 of the 30 is cleaned, the oxide film is removed as shown in FIG. 5B, and the electrical contact between the brush 33 and the commutator 30 can be kept good. At the same time, the lubricating oil is sufficiently supplied to the entire bearing portion of the DC motor 8 by this swinging rotation.

  At the same time, since the ball valve body 34 also swings by the same angle as the output shaft 10 of the valve electric actuator 1, the swing can avoid sticking of the stem, and sludge accumulated between the ball valve body 35 and the disc seat can be removed. It can be removed, and sticking can be prevented from occurring on the valve side.

  In this self-idling, the gear train 9 of the other valve electric actuator 1 also swings and rotates, and the main / sub limit switch also operates. This has the effect of improving the situation and preventing malfunction of the electric actuator 1 for valves.

  Further, when the swinging operation of the DC motor 8 is performed, the control unit 6 measures the current flowing through the armature of the DC motor 8 with a current detector (step S06), and when the current is not flowing, the DC motor 8 is judged to be a contact failure due to the formation of the oxide film 32 on the surface 31 of the commutator 30, and the motor drive circuit 7 stops the supply of power to the DC motor 8 and issues a motor contact failure alarm (step S07). .

  If an abnormal current value is measured (step S08), the bearing of the DC motor 8, the bearing of the gear train 9, the gear grease breakage, the valve stem sticking, the ball sticking, the biting, etc. Is predicted, a mechanism unit abnormality warning is issued (step S09).

  During the swing operation of the DC motor 8, the control unit 6 reads the swing operation voltage change ΔV1s of the electric double layer capacitor 14 before and after the swing operation of the DC motor 8 shown in FIG. 7, and ΔV1s is a preset voltage change width. Is exceeded, it is determined that the electric double layer capacitor 14 is deteriorated (step S10), and an electric double layer capacitor life warning is issued (step S11).

  After the oscillating operation of the DC motor 8, the control unit 6 controls the electric double layer capacitor 14 with a constant current from the power supply unit 4 through the secondary power supply charging circuit in a state where energization to the DC motor 8 is prohibited. DC power is supplied to charge the electric double layer capacitor 14 (step S12). The control unit 6 measures the received voltage width ΔVc (charging completion voltage−charging start voltage) and the charging time tc required for the charging shown in FIG. 7, and the inclination “ΔVc / tc” is preset. If the value deviates, it is determined that the electric double layer capacitor 14 has deteriorated (step S13), and a life warning of the electric double layer capacitor 14 is issued (step S14).

  As described above, when a valve equipped with the electric actuator for a valve according to the present invention is used as an emergency shut-off valve or an emergency release valve, the DC motor is swung by a self-idling function periodically and automatically. Cleans the DC motor commutator surface and limit switch contacts, prevents oil out of actuator gear trains and operating mechanisms such as bearings, avoids sticking of the stem, and removes sludge accumulated between the valve disc and disc. At the same time, the self-diagnosis function at the same time as the swing operation diagnoses the failure occurrence status of the DC motor, gear train, limit switch, etc. in the valve actuator and the electric double layer capacitor, and alerts if a failure has occurred. Emergency shutdown by promptly repairing, repairing, or replacing defective parts. Or it is possible to enhance the maintenance of the reliability of the emergency release valve, its utility value is very large.

  The present invention can be applied to a butterfly valve as well as a ball valve. In the flow characteristic graph (not shown) showing the relationship between the valve opening and the flow path, the butterfly valve has a flow rate of 0% within a range of 0 to 8% and a range of 90 to 100%. In the valve, the flow rate is saturated at about 100%. Accordingly, by setting the swing range of the disk-shaped disc of the butterfly valve within the above-mentioned range, the emergency shutoff valve or emergency release valve of the valve equipped with the valve electric actuator according to the present invention is installed, as with the ball valve. As the reliability can be increased.

DESCRIPTION OF SYMBOLS 1 Electric actuator for valves 2 Valve 3 Operation part 4 Power supply part 5 Secondary power supply part 6 Control part 7 Motor drive circuit 8 DC motor 11 Position detector 14 Electric double layer capacitor 30 Commutator 32 Oxide film

Claims (6)

An electric actuator for opening and closing a valve with a DC motor, wherein a power supply unit and a secondary power source unit are connected to the DC motor via a control unit, and the control unit performs an opening and closing operation of the valve within a certain period. A self-idling function that finely operates the DC motor using the power charged in the secondary power supply unit at an angle within a range where the valve does not pass through or within a range where the flow rate is satisfied. And a self-diagnosis function for diagnosing at least a commutator contact failure in the DC motor when no current is flowing in the DC motor during the fine movement operation .   The valve according to claim 1, wherein the valve is a butterfly valve or a ball valve, and the fine movement operation in the case of the butterfly valve is performed within a range of opening degree 0 to 8%, or opening degree 90 to 100%. Electric actuator for valves.   An emergency shut-off valve / emergency release valve equipped with the electric actuator for valves according to claim 1.   The emergency shut-off valve / emergency release valve according to claim 3 connected to a seismic sensor. An electric actuator for opening and closing a valve with a DC motor, wherein a power supply unit and a secondary power source unit are connected to the DC motor via a control unit, and the control unit performs an opening and closing operation of the valve within a certain period. A self-idling function that finely operates the DC motor using the power charged in the secondary power supply unit at an angle within a range where the valve does not pass through or within a range where the flow rate is satisfied. And a self-diagnosis function for diagnosing at least a commutator contact failure in the DC motor when a current does not flow through the DC motor during the fine movement operation . Said valve is a butterfly valve or ball valve, said fine operation when the butterfly valve is a valve according to claim 5 in which to perform within the range of 0-8% opening, or 90% to 100% An abnormality diagnosis method for an electric actuator.

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