JPS5933795B2 - 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]

2. Description of the Related Art Conventionally, there is a method known in Japanese Utility Model Publication No. 51-20510 as a method for opening/closing an electric valve or the like using a DC motor.

In the detailed explanation of the invention, it is stated that [the power supply input section of the DC motor is equipped with diodes with opposite directions, and a limit switch that opens and closes the opening and closing valve in two positions, By opening and closing these switches, supply and cut-off of the power supply current is controlled without performing the reverse current blocking action of the diode. A diode and an on-off valve are provided with a limit switch that opens at one position and closes at another position, and a limit switch that operates in the opposite direction.To summarize, the operation of these two limit switches is shown in Figure 1. It is as follows.

In other words, with the two limit switches used in the conventional example, one of the limit switches is always open while the on-off valve moves from one position to another, so the polarity of the voltage applied during operation cannot be changed. There was a problem in that it was not possible to reverse the direction of operation midway through the operation.

In other words, with this method, voltage is applied to change the opening/closing from one position to another, and if you notice an error in the operation during operation or want to return to the original position for some reason, the voltage is applied. Even if you apply it in the opposite direction, it will not energize and it is impossible to return it from the middle, so you must always move the valve to a different final position and operate the limit switch.

This is clear from Figure 1, and a valve that has begun to open has the major disadvantage of not being able to enter the closing operation unless it is fully opened. It was unsuitable for use in commercial or automatic control applications.

[Purpose of the invention]

The purpose of the present invention is to solve the drawback of the conventional DC drive method, that is, the direction of operation cannot be changed during opening or closing operation, and to provide a DC drive electric motor that can be used for normal remote control or automatic control. The purpose is to provide a method for opening and opening valves, etc.

[Structure of the invention]

As shown in FIG. 2, the present invention has a structure for achieving the object, which includes a DC motor 1 whose rotation direction is reversed by reversing the applied voltage, and a DC motor 1 which opens and closes valves etc. driven by the output of this motor. It consists of a device (hereinafter referred to as load) 2, a limit switch 3 for stopping the load in the fully open position, a limit switch 4 for stopping the load in the fully closed position, a diode 5 and terminals 7 and 8. , a circuit in which a limit switch 3 and a diode 5 are connected in series [hereinafter referred to as circuit S] and a circuit in which a limit switch 4 and a diode 6 are connected in series [hereinafter referred to as circuit] are connected in parallel. [Hereinafter, the circuit in which circuit a and circuit A are connected in parallel will be referred to as circuit C.] The circuit C and the DC motor 1 are connected in series between the terminals 7 and 8, and the diode 5 opens the load 2. The diode 6 is connected in a forward direction with respect to the direction of the current that moves the load 2 in the closing direction, and the diode 6 is connected in a forward direction with respect to the direction of the current that moves the load 2 in the closing direction, and the diode 6 is connected in a forward direction with respect to the direction of the current that moves the load 2 in the closing direction. By reversing the direction, the load driven by the DC motor is opened and closed,
At the start of the opening/closing operation, one of the limit switches mentioned above is on and the other limit switches are off, and in the middle of the opening/closing operation, both limit switches are on.
At the end of the opening/closing operation, one of the limit switches is turned off and the other limit switches are turned on.

[Explanation of Examples]

Hereinafter, the opening/closing method of the present invention will be explained with reference to the drawings.

FIG. 2 is a configuration diagram, where solid lines indicate electrical connections and chain lines indicate mechanical connections.

FIG. 3 shows the relationship between the open/closed state and the on/off state of the limit switch.

In FIG. 2, 1 is a DC motor connected to a load 2. In FIG.

The load 2 is equipped with a limit switch 3 for stopping the fully open position which is turned off when the load is fully open, and a limit switch 4 for stopping the fully closed position that is turned off when the load is fully closed.

Furthermore, these electrical connections are as shown in FIG. 2, which shows a state in which the load 2 has reached the fully closed position, the limit switch 3 is on, and the limit switch 4 is off.

In this state, if a positive voltage is applied to terminal 7 and a negative voltage is applied to terminal 8, current flows from terminal 7 → diode 5 → limit switch 3 → DC motor 1 → terminal 8, and the load 2
does not move in the open direction, the limit switch 4 turns on, continues to operate in the open direction, and when the fully open position is reached, the limit switch 3 turns off, the DC motor 1 stops, and the load 2 maintains the fully open position. do.

Also, when you want to close the load 2 after the above condition, if you apply a positive voltage to terminal 8 and a negative voltage to terminal 7, the current flows from terminal 8 → DC motor 1 → limit switch 4 → diode 6 → terminal 7, The load 2 starts to move in the closing direction, the limit switch 3 turns on, and continues to move in the closing direction, and when it reaches the fully closed position, the limit switch 4 turns off, the DC motor 1 stops, and the load 2 moves to the fully closed position. maintain.

Note that the above explanation describes the operation from fully closed to fully open, or from fully open to fully closed.
, 8, the load 2 can be operated in either the opening or closing direction as desired.
It is clearer than the diagram.

〔Effect of the invention〕

As described above, the opening/closing method of the present invention solves the disadvantage of the conventional method, which is that the direction of operation cannot be changed during the opening or closing operation, and the opening/closing method of the present invention can arbitrarily reverse the direction of operation. It is industrially useful because it can be used for automatic control.

[Brief explanation of drawings]

Fig. 1 is a diagram of a conventional example showing the on and off states of a limit switch of an on-off valve operating mechanism driven by a DC motor;
The figure is a block diagram of the opening/closing method of the present invention, with solid lines indicating electrical connections and broken lines indicating mechanical connections. FIG. 3 is a diagram showing the relationship between the opening/closing state and the on/off state of the limit switch in the opening/closing method of the present invention. 1: DC motor, 2: Load (opening/closing device such as solenoid valve), 3
: Limit switch for fully open position stop, 4: Limit switch for fully closed position stop, 5, 6: Diode, 1, 8: Terminal.

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 series are provided in parallel, 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 source to the DC motor, the DC motor can be rotated forward or backward, thereby causing the switchgear to rotate. 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.