JPH0322601Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field This invention relates to an electric valve drive device configured using an electromagnetic contactor.

(b) Prior art When an electromagnetic contactor is incorporated into an electric valve drive device to turn on and off the AC power supply, vibrations such as water hammer and cavitation generated in the piping in which the electric valve is installed can cause electromagnetic A situation has arisen in which the contactor of the contactor swings, the operating or stationary contact opens or closes, and the self-holding circuit is activated, causing the electric valve to operate to the fully open or fully closed position.

For example, in the circuit configuration diagram of an electric valve drive device incorporating a conventional electromagnetic contactor shown in Fig. 2, when fully opening the electric valve 1, the opening push button switch is
When OS is pressed, coil VO is excited and contacts OC1~
As OC3 closes, normally closed contact OC4 opens,
The motor 2 rotates in the opening direction. At this time, the contact
Even if OC5 is closed and the contact of the opening pushbutton switch OS is opened, electricity still flows through the contact OC5 to the coil VO.
continues to be excited and enters a self-holding state. When electric valve 1 reaches full open, the contact of full open limit switch OLS is opened, coil VO is demagnetized and contact OC is opened.
1 to OC3, OC5 are opened and contact OC
4 is closed and motor 2 is stopped. To fully close electric valve 1, press the closing pushbutton switch CS to energize the coil VC and close the contacts CC1 to CC3, CC.
5 closes, the normally closed contact CC4 opens, and in the self-holding state, the motor 2 rotates in the closing direction until the contact of the fully closed limit switch CLS is opened and the coil VC is demagnetized. If the motor stops mid-rotation, press the stop pushbutton switch SS to release the self-hold. In a configuration that allows the valve to be opened and closed in this way, if the valve contacts OC1 to OC5 are damaged due to an impact while the valve is stopped at the fully closed position.
bounces, and temporarily contacts OC1 to OC3,
When OC5 is closed and contact OC4 is opened, the power to the operation circuit is turned off to the stop pushbutton switch.
Energize the coil VC through SS, contact OC5, fully open limit switch OLS, and contact CC4. Even after the shock is released, the self-holding state is maintained, so the valve operates to the fully open position. Even when it is in the fully open position, a similar impact will cause it to operate to the fully closed position.

Therefore, in order to prevent such malfunctions, it is possible to make the magnetic contactor solid-state, but since it requires turning the motor's large current on and off, it is not an appropriate measure in terms of size and price. I can't say that.

(C) Purpose This invention aims to solve the problem that when an electromagnetic contactor is incorporated to turn ON and OFF the forward and reverse rotation of the drive motor in an electric valve drive device, the self-holding circuit of the electric valve drive device prevents the device from receiving excessive shock. Therefore, this invention has been made to prevent the electric valve from malfunctioning unnecessarily, and it is an object of the present invention to provide an electric valve driving device that does not operate the self-holding circuit while receiving an impact.

(D) Configuration The electric valve drive device according to this invention operates in an electric valve opening operation of an electromagnetic contactor in which an electric valve opening electromagnetic coil equipped with a self-holding circuit is energized by the closing operation of an electric valve opening switch. A three-phase alternating current On the line connecting the power supply and the terminal of the motor for driving the electric valve,
An electric valve drive motor is interposed so that it can freely rotate in forward and reverse directions, and a full-open limit switch is connected in series with the self-holding circuit to release the self-holding circuit of the electric valve opening electromagnetic coil from the power supply when the electric valve is in the fully open position. At the same time, in the electric valve driving device, a fully closed limit switch is connected in series with the self-holding circuit for releasing the self-holding circuit of the electric valve closing electromagnetic coil from the power supply when the electric valve is in the fully closed position. In parallel with the self-holding circuit of the opening electromagnetic coil and the self-holding circuit of the electric valve closing electromagnetic coil, respectively, the electric valve opening switch and the electric valve are connected in parallel with each other, and the electric valve opening switch and the electric valve A timer with a non-contact output having a set time shorter than the closing operation time of the closing switch is connected, and electrical elements that become conductive when the set time of the timer elapses are connected in series with each of the self-holding circuits, and the electric The electric valve opening contact, which is closed by the excitation of the valve opening electromagnetic coil, and the electric valve closing contact, which is closed by the excitation of the electric valve closing electromagnetic coil, are connected in parallel to each other, and the timer The present invention is characterized in that an interlock mechanism is provided in each of the lines connecting the electric valve opening electromagnetic coil and the electric valve closing electromagnetic coil.

Therefore, even if an impact vibrates the contactor of the electromagnetic contactor, causing the self-holding contact to swing and close the open contact, the self-holding circuit will not operate until the non-contact output of the timer circuit becomes conductive. This means that the electric valve will not malfunction due to an impact within the time set by the timer.

(E) Embodiment FIG. 1 is a circuit diagram showing the configuration of an electric valve drive device which is an embodiment of this invention. Similar to the conventional device shown in Fig. 2, when the electric valve 1 is fully opened, the opening pushbutton switch OS is pressed to energize the coil VO, which closes the contacts OC1 to OC3 and closes the normally closed contact.
OC4 opens and motor 2 rotates in the opening direction of electric valve 1, but at the same time, newly provided contact OC6 closes and timer 3 interposed between the excitation coil and the power source operates. After the timer 3 is activated, it operates so that its purely electrical element becomes conductive after a set time has elapsed; A set time is set that is longer than the instantaneous time that the switch touches and shorter than the switch-on time. Therefore, while the opening pushbutton switch OS is being turned on, the set time of the timer 3 elapses, and the electrical element becomes conductive and the excitation coil VO is self-maintained through the contact OC5. When the electric valve 1 reaches full open, the contact of the full open limit switch OLS is opened, the coil VO is demagnetized, and the contacts OC1 to OC3,
OC5 and OC6 are opened, contact OC4 is closed, and motor 2 is stopped.

If the motor 2 stops mid-rotation, press the stop pushbutton switch SS to release the self-holding.
When fully closing the electric valve 1, the closing pushbutton switch CS, coil VC, contacts CC1 to CC5, timer 3 for the newly installed contact CC6, and fully closing limit switch CLS operate in the same manner as above, and the motor 2
rotates in the valve closing direction.

In this way, a self-holding circuit is constructed by interposing the non-contact output timer 3, and its operation setting time is set to be longer than the time for the contacts to close due to the anticipated impact of a water hammer, etc.
Depending on the impact, contact OC5, OC6 or CC5,
Even if the CC 6 is closed, the purely electrical elements of the non-contact output timer 3 do not conduct, power is supplied to the self-holding circuit, the coil is energized, and the motor 2 does not rotate.

(F) Effect The electric valve drive device according to this invention is configured and operates as described above, so even if the contact of the electromagnetic contactor swings due to the impact applied to the electric valve and the self-holding contact closes, The excitation coil is prevented from being electrically connected to the power source by the timer circuit, thereby preventing the motor-operated valve from malfunctioning. Furthermore, compared to the case where the electromagnetic contactor is made into a solid state, it can be manufactured at a lower cost as a measure to prevent malfunction.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of an electric valve drive device according to an embodiment of this invention, and FIG. 2 is a circuit diagram showing the configuration of a conventional device. 1...Electric valve, 2...Electric valve drive motor, 3...Timer, OS...Push button switch for electric valve opening, CS
...Push button switch for electric valve closing, VO...Excitation coil for electric valve opening, VC...Excitation coil for electric valve closing, OC
1 to OC6...Electric valve opening contact, CC1 to CC6...Electric valve closing contact, OLS...Full open limit switch,
CLS...Fully closed limit switch.

Claims (1)

[Scope of utility model registration request] When the electric valve opening switch is turned on, the electric valve opening electromagnetic coil equipped with a self-holding circuit is energized. A line that connects the electric valve closing operation contact of the electromagnetic contactor, in which the electric valve closing electromagnetic coil equipped with a self-holding circuit is excited, to the three-phase AC power supply and the terminal of the electric valve drive motor in parallel with each other. An electric valve driving motor is interposed so as to be able to freely rotate in forward and reverse directions, and a full-open limit switch is connected in series with the self-holding circuit to release the self-holding circuit of the electric valve opening electromagnetic coil from the power supply when the electric valve is in the fully open position. In the electric valve driving device, a fully closed limit switch is connected in series to the self-holding circuit, and the self-holding circuit of the electric valve closing electromagnetic coil is disconnected from the power supply when the electric valve is in the fully closed position. In parallel with the self-holding circuit of the electromagnetic coil for opening the electric valve and the self-holding circuit of the electromagnetic coil for closing the electric valve, the electric valve opening switch and Connecting a timer with a non-contact output having a set time shorter than the closing operation time of the electric valve closing switch, and connecting in series with each of the self-holding circuits an electric element that becomes conductive when the set time of the timer elapses; An electric valve opening contact that is closed by the excitation of the electric valve opening electromagnetic coil and an electric valve closing contact that is closed by the excitation of the electric valve closing electromagnetic coil are arranged in parallel with each other, An electric valve driving device characterized in that an interlock mechanism is provided in each of the lines connecting the timer and the electric valve opening electromagnetic coil and the electric valve closing electromagnetic coil.