JPS5933794B2 - How to open and close electric valves, etc. - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for opening and closing an electric valve, etc.

[Prior art]

Conventionally, the method for opening and closing switching devices such as electric valves is to rotate an AC motor in the forward or reverse direction, thereby opening and closing the switching device, and when it is fully open or fully closed, operate a limit switch to stop the power supply to the motor. method is used.

However, since this method uses an AC motor as the drive source, three electric wires are required to rotate forward and reverse.
When used for field irrigation, the distance from the power source to the electric motor is long, which is uneconomical, and in the event of a power outage, it is necessary to prepare an emergency AC power source, which can be costly.

In addition, a method using a DC motor as one drive source and two electric wires for power supply is known in Japanese Utility Model Publication No. 51-20510, but as clearly stated in the registered claims, Since the on-off valve is equipped with a reverse diode and a limit switch that opens at one position and closes at another position, the power supply current is always supplied to the motor through the diode, which consumes a lot of power. , the diode may be damaged if it is struck by lightning during operation, and it is impossible to switch to reverse operation in the middle of opening or closing operation. It has the disadvantage that it cannot be reversed unless it is fully closed, making it unsuitable for use as an automatic regulating valve.

[Purpose of the invention]

The present invention solves the disadvantages of the above-mentioned conventional methods, such as the need for three electric wires, which is uneconomical, the high equipment cost for an emergency power source, and the fact that when using a DC motor, a diode is always used. This was done with the aim of solving the problems of high power consumption due to the intervening operation, the diode being easily damaged by lightning strikes, and the fact that the direction of operation cannot be reversed during opening or closing operations, making it unsuitable for automatic adjustment. It is.

[Structure of the invention]

In order to achieve the above-mentioned object, the present invention, as shown in FIG. 1 and FIG. By providing two circuits, connecting these diodes in opposite directions to the current flow direction in the wiring, and switching the direction of the current from the DC power source to the DC motor, The DC motor is rotated in forward and reverse directions, thereby opening and closing the above-mentioned switchgear. When the above-mentioned opening/closing operation starts, one of the limit switches is on and the other limit switches are off, and the above-mentioned opening/closing operation starts. In the middle, all the limit switches are on, and at the end of the opening/closing operation, one of the limit switches is off and the other limit switches are on.

[Explanation of Examples]

Hereinafter, the operation of the method for opening and closing an electric valve, etc. of the present invention will be explained with reference to the drawings.

1 and 2 show an embodiment of the opening/closing method of the present invention. In FIG. 1, 1 is a DC motor with a permanent magnet field connected to an opening/closing device 2 such as an electric valve; During the wiring of this DC motor, two circuits 7 and 8 in which diodes 3 and 4 and limit switches 5 and 6 are connected in parallel are constructed so that the directions of diodes 3 and 4 are opposite to each other with respect to the current flow direction. It is inserted so that

When a DC power supply (not shown) applies a positive voltage to terminal 9 and a negative voltage to terminal 10, current flows from terminal 9 to circuit 7, passes through limit switch 5, which is closed, and
It flows through the DC motor 1 and the diode 4 of the circuit 8 (the limit switch 6 of the circuit 8 is turned off) to the terminal 10.

Assuming that the switchgear 2 is fully open before the start of energization,
As the DC motor 1 rotates forward, the switchgear 2 begins to open.
At the same time, the limit switch 6, which is interlocked with the opening/closing device 2 by a suitable method such as a cam mechanism, is closed, and the circuit 8 is short-circuited.

After a further period of time, when the switchgear 2 becomes fully open, the limit switch 5, which is interlocked with the switchgear 2 by an appropriate method such as a cam, is turned off, and the current from the DC power source is cut off in the circuit 7, causing the DC motor to 1 stops, and the switchgear 2 maintains the fully open position.

Next, when closing the switchgear 2 from the fully open state, switch the direction of the current from the DC power supply and connect the terminal 10 with a positive
When a negative DC voltage is applied to terminal 9, the current flows through circuit 8.
The current flows through the closed limit switch 6, the DC motor 1, and the diode 3 of the circuit 7 to the terminal 9.

At this time, since the DC motor 1 rotates in the reverse direction, the switching device 2 connected thereto begins to close, and at the same time, the limit switch 5, which has cut off the circuit 7, is closed, and the circuit I is short-circuited.

After a further period of time, when the switchgear 2 becomes fully open, the closed limit switch 6 is turned off, the current is cut off in the circuit 8, the DC motor 1 is stopped, and the system returns to its initial state.

Further, FIG. 2 shows a case where two circuits 11 and 12 are arranged in series on one line of the wiring of the DC motor 13. In FIG.

In this case, when a positive DC voltage is applied to the terminal 14 and a negative DC voltage is applied to the terminal 18, the current flows through the limit switch 15 of the circuit 11 and the diode 16 of the circuit 12 [limit switch 1
7 is disconnected] and flows through the electric motor 13 to the terminal 18.

As the DC motor 13 rotates forward, the switching device 19 starts to open from the closed state, and at the same time, the limit switch 17 closes and the circuit 12 is short-circuited.

After a period of time, when the switchgear 19 is fully opened, the limit switch 15 is turned off and the current is cut off in the circuit 11, and the DC motor 1
3 stops.

To close the switchgear 19 from this state, switch the direction of the current from the DC power supply and apply a positive voltage to the terminal 18 and a negative voltage to the terminal 14.
, circuit 12 closed limit switch 17, circuit 1
The current flows through the first diode 20 to the terminal 14.

At this time, the DC motor 13 rotates in the reverse direction, and as the switchgear 19 is closed, the limit switch 15 is closed, and the circuit 1
1 is short-circuited, and when the switchgear 19 is fully closed, the limit switch 17 is turned off and the current is cut off, and the DC motor 1
3 stops and the system returns to its initial state.

The above explanation has been about the operation from fully closed to fully open, or from fully open to fully closed. However, by reversing the polarity of the applied voltage during opening and closing, it is possible to arbitrarily rotate the DC motor in the normal direction. Of course, the switch can be reversed to operate the opening/closing device in either the opening or closing direction.

〔Effect of the invention〕

The opening/closing method of the present invention saves the number of wires compared to using an AC motor, consumes less power than the conventional method using a DC motor, and prevents diodes from being damaged by lightning strikes. However, since the operating direction can be reversed during opening/closing operation, it has the advantage of being usable for automatic control valves, etc., so it is applicable not only to electric valves used for field irrigation, but also to various other opening/closing devices. It is industrially advantageous.

[Brief explanation of the drawing]

1 and 2 show two embodiments of the method according to the invention. 1.13: DC motor, 2.19: Opening/closing device such as electric valve, 3, 4.16, 20: Diode, 5゜6.15, 1
7: Limit switch, 7, 8, 11° 12: Circuit.

Claims (1)

[Claims] 1 In the wiring of a DC motor connected to a switching device such as an electric valve, two circuits in which a diode and a limit switch are connected in parallel are installed in series, and the orientation of these diodes is determined according to the current flow in the wiring. By connecting the DC motors in opposite directions, and switching the direction of the current from the DC power supply to the DC motor, the DC motor can be rotated in the forward direction or in the reverse circuit, thereby rotating the switchgear. This is a method of opening and closing, and at the start of the opening and closing operation, one of the limit switches is on and the other limit switches are off, and in the middle of the opening and closing operation, both limit switches are on.
A method for opening and closing an electric valve, etc., characterized in that when the opening and closing operation is completed, one of the limit switches is turned off and the other limit switch is turned on.