JPH11141728A - Control device for drain plug provided with pressure switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent reverse flow of water from a feed pipe of each household to a drain pipe by arranging a pressure switch for outputting a polarity of direct current power supply to drive a drain plug in a closing direction, in the case where pressure in a piping is constant pressure or less, in a device for opening/closing the drain plug by driving a direct current motor. SOLUTION: When a plug opening switch OP is turned on by an user, a coil R of a latching relay is energized, a contact point is positioned on a position r, and a drain plug V is opened by a direct current motor M. When a plug closing switch CL is pushed in this condition, a coil S of a latching relay is energized, the contact point is changed over to a position s, and the direct current motor M is driven in a closing direction. In the opening condition, when water pressure is a constant value or less which is set in a pressure comparing section for the reason of suspension of water supply, an output of AND becomes signal 1 for a prescribed time, and thereby, the coil S of the latching relay is energized for a prescribed time through a transistor. As a result, the contact point is switched to the position s, and drain plug V is opened by the direct current motor M.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention has a pressure switch,
The present invention relates to a control device for a motor that drives a water tap used in a cold region to prevent freezing of a water pipe.

[0002]

2. Description of the Related Art In cold regions, a water tap for draining water from a water pipe has conventionally been used in order to prevent the water pipe from freezing during the winter season. A drain valve is a three-way valve that has an inlet, an outlet, and a drain port in a valve box installed in a place where it does not freeze.The valve element that moves in the valve box is connected to a spindle via a rod or directly to a spindle. Is operated by a handle or the like.In the open state, water flows from the inflow port to the outflow port, but does not flow to the drain port. Water is used by opening and closing the apparatus such as the above, and in the closed state, the water upstream of the drain port is stopped at the inflow port, and the water in the downstream pipe of the outflow port is discharged to the outside through the drain port to prevent freezing. In order to open and close the drain plug, a device that switches the polarity of a DC power supply via a latching relay and is driven by a motor is also employed. Latching relays have two coils. When one coil is energized for a certain period of time, the contacts are switched. When the current is lost, the switched state is maintained, and the contacts are restored by energizing the other coil. If the other coil is energized while the other coil is energized, or if the same coil is energized again after energizing one coil, the contact keeps its state switched to that side. By switching the polarity of the DC power supply by an external operation, the motor that was cut off is driven, decelerated through gears, converted into linear motion by the spindle, and the valve body in the valve box is driven. When a fixed amount is moved, the limit switch is switched to cut off the motor current.

Apart from freezing prevention, as a method of supplying water to high-rise houses, a method of once assembling water in an elevated water tank and then supplying water to each house has been adopted. Accordingly, for example, a backflow prevention valve for preventing the reverse flow of water from the water supply pipe of each house to the water distribution pipe when water is cut off or the like is employed. The check valve controls the passage according to the direction of water flow.
In the normal flow direction, the valve element in the valve box opens to secure a water passage, and for the reverse flow, the valve element closes to shut off the water path.

[0004]

As described above, prevention of freezing and prevention of backflow are different technologies. The present invention provides a water supply system for each house by closing the drain valve when water reverses from the water supply pipe of each house to the water distribution pipe due to, for example, water cutoff, and discharging the water in the downstream pipe of the water drain pipe from the drain port. The purpose is to prevent backflow of water from the pipe to the water pipe.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a water drain valve for opening and closing a water drain valve by driving a DC motor with a DC power source whose polarity is changed by turning on and returning one of two operation switches. In the drive device, by outputting a signal when the pressure in the pipe in which the water tap is installed becomes equal to or less than a certain pressure, the polarity of the DC power supply is output so as to drive the water tap in the closing direction. It has a pressure switch.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, when the water pressure drops from a normal value to a predetermined pressure or less due to, for example, water cutoff, the water drainage stopper is closed, and the low water pressure lamp is turned on to turn off the water. Although it is understood that there is, the lamp may be turned on when the water pressure is equal to or higher than a certain pressure, and water may not be used when the lamp is off. Further, when the water pressure falls below a certain pressure and the drain plug is closed, the drain plug may be kept closed until the water pressure recovers to a certain value or more.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, V is a drain plug having a valve (not shown) that linearly moves by reducing the rotation of a motor M via a gear (not shown). r and s are R and S
Are two sets of contacts of a latching relay having two coils, and a power supply relay for changing the polarity of the power supply. In the figure, the contact point is r and the open side, and conversely, the contact s is the closed side. When the user presses and turns on the opening switch OP, and the coil R of the latching relay is energized, the contact point becomes the position r in the figure,
When the user stops pressing, the plug opening switch OP returns, and the bias of the coil R is released, but the contact keeps the position of r in the figure. Further, when the user pushes the closing switch CL to turn it on and the coil S of the latching relay is energized, the contact switches from the position shown in the drawing to the other end s. The bias of S is released, but the contact keeps the position switched to s at the other end in the figure. P is a pressure sensor installed upstream of the drain plug V to detect the pressure in the pipe and change it into a voltage.
L1 and L2 are limit switches for detecting the state of the water tap V, both of which are on the side of the figure, and when the contact of the power supply relay is also on the side of r in the figure, the drive current does not flow through the DC motor M, The water tap V is in an open state.

When the closure switch CL is pressed in this state, the coil S of the latching relay is energized, the contact of the power supply relay is switched to s at the other end, and the DC motor M is driven from the drive power supply Vd through the diode D1 in the direction of the arrow. The drive current flows through. As a result, the valve body of the drain plug V starts to move in the closing direction, and first, the limit switch L2 is switched from the position shown in the drawing to the other end, but the DC motor M continues to be driven.
When the valve body of the drain valve V moves by a certain amount, the limit switch L
1 also switches from the position shown in the figure to the other end, the drive current of the DC motor M is cut off, and the water drainage plug V is closed and stopped. In this state, the water upstream of the water tap V is stopped at the inflow port, and the water in the downstream pipe from the outflow port is taken out of the drain port to prevent freezing.

As described above, when the water drainage plug V is in the closed state, the contacts of the power supply relay and the limit switches L1 and L2 are both switched from the position of FIG. 1 to the other end. To return to the open state. That is, the coil R of the latching relay is energized, and the contact point of the power supply relay returns to the position r in the drawing from the other end. Flows. As a result, the valve body of the drain plug V starts to move in the opening direction, and first, the limit switch L1 returns to the position shown in the figure from the other end of the figure, but the DC motor M continues to be driven. When the valve body of the drain plug V moves by a certain amount, the limit switch L2 returns to the position shown in the drawing from the other end of the drawing, the drive current of the DC motor M is cut off, and the drain plug V is opened and stopped. In this state, the inflow port and the outflow port of the drain plug are connected to each other to shut off the drain port.

Pc is a pressure comparator which sets one input to a pressure sensor P and sets the other input voltage to a constant value, and outputs 1 if one pressure sensor P is higher than that value and 0 if lower. Output. The output Pc of the comparator is inverted by an inverter to become Pc ', from which it becomes a low water pressure lamp Pl through a transistor, while it becomes Pct through a delay part of a resistor and a capacitor and an inverter, and becomes one input of AND. At the same time, Pc 'becomes the other input of AND, and the output of AND becomes the coil S of the latching relay via the switch of the transistor in parallel with the closing switch CL. Vc is a control power supply.

When the pressure is a normal value equal to or higher than the set value, the output Pc of the pressure comparator and its inverted output Pc 'are 1 and 0, respectively, and the low water pressure lamp Pl via the transistor is used.
Has disappeared, the output of AND is 0, and the transistor is shut off, so that the coil S of the latching relay is not energized. When the water drainage V is in the open state and the water pressure falls below a certain value set by the pressure comparison unit due to, for example, interruption of water supply, the water drainage V is closed as follows.

The output Pc of the pressure comparator and its inverted output P
c ′ outputs low voltage signals inverted to 0 and 1, respectively, and the input of AND is 1 from the direct input from Pc ′, and the input Pct via the delay unit and the inverter is charged by the capacitor and the output of the inverter becomes 0 It becomes 1 only until it becomes 0, and then becomes 0. That is, when the output of the AND becomes equal to or lower than the set normal value, the signal 1 is output for a predetermined time, and the coil S of the latching relay is energized through the transistor for a predetermined time. As a result, the contact of the power supply relay is switched to s at the other end in FIG.
, A drive current flows in the direction of the arrow via the diode D1 and the valve body of the water drainage V starts to move in the closing direction, the limit switch L2 switches from the position of FIG. 1 to the other end, and the limit switch L1 also moves The position is switched from the position to the other end, the drive current of the DC motor M is cut off, and the water tap V is closed and stopped. In this state, the inflow port and the outflow port of the water tap V are shut off, and the water in the downstream pipe is discharged from the drain port to the outside to prevent the water from flowing back into the water distribution pipe upstream of the water tap V. Thereafter, only the low water pressure lamp Pl is turned on and there is no change. When the water pressure is restored to the normal value after the interruption of the water supply, the output Pc of the pressure comparison unit and its inverted output Pc 'return to 1 and 0, respectively, and the low water pressure lamp Pl goes out. When the pressure becomes equal to or less than the normal value, the AND outputs the signal 1 for a predetermined time determined by the time constant of the delay unit, and energizes the coil S of the latching relay for a predetermined time via the transistor. The time is longer than the time required to switch the contact from r to s.

FIG. 2 shows another embodiment of the present invention.
T2 and T3 are inputs of the display unit corresponding to FIG. 1, and each resistance is made sufficiently larger than the resistance of the DC motor M. Drain stopper V
Is in the open state, and the contact of the latching relay is on the r side in FIG.
When the limit switches L1 and L2 are also on the side of FIG. 1, the inputs t1, t2, and t3 are 0, 0, and 1, respectively, the NOR output is 0, and the AND output OP1 is 1. From this state, when the contact of the latching relay is switched to the s side and the DC motor M is driven in the closing direction, the inputs t1, t
2 and t3 are 0, 1, and 0, respectively. This does not change even if the limit switch L2 is switched. When the DC motor M is driven in the closing direction and the water drainage valve V is in the closed state and the limit switch L1 is also switched, the inputs t1, t2, and t3 are 0, 0, respectively. , 0, the output is 1 for NOR, and O
P1 becomes 0. Conversely, in the case of driving in the opening direction, when the contact of the latching relay is restored and the DC motor M is driven, the respective inputs t1, t2, and t3 become 1, 0, 1 respectively, the output is NOR, and the output is OP1. Becomes 0. This does not change even when the limit switch L1 returns, and the DC motor M is driven in the opening direction. When the drain switch V is opened and the limit switch L2 is also returned, all the states return to the initial state of FIG. 1, and the inputs t1, t2, and t3 become 0, 0, 1 respectively, and the outputs are 0, NOR, and AND. OP
1 becomes 1. That is, the output of Noah becomes 1 only when the water drainage plug V is stopped in the closed state, and only at this time the closing indicator Cl via the transistor is turned on, and the AND output OP1 becomes 1. This occurs only when the water drainage plug V is stopped in the open state, and only at this time the open indicator lamp Op via the transistor is turned on.

Pc 'in FIG. 2 is an inverted output of the output Pc of the pressure comparison unit corresponding to FIG. 1, and the NAND with the AND output OP1 of the display unit is one input of two NAND flip-flops. , Pc ′ and Pct via the delay unit and the inverter therefrom are the other inputs of the flip-flop. The output Q of the flip-flop becomes Qt ′ via the delay unit and the inverter, and the AND of this and Q is connected to a transistor in parallel with the closing switch CL, and the NOR of Qt ′ and Q is in parallel with the opening switch OP. Connected to a transistor. Plq from the output Q of the flip-flop via the transistor is Pc ′ in FIG.
Is a low water pressure lamp which is different from the low water pressure lamp Pl which is turned on when Q is 1, and is turned on when Q is 1.

As described above, when the closing switch CL is pressed when the water drainage plug V is in the open state, the coil S of the latching relay is energized, the contact of the power supply relay is switched to the s side, and the motor M is driven. The valve body moves by a predetermined amount and the limit switch switches in the order of L2 and L1 to be in the closed state, the motor M stops, and conversely, the open switch OP
When the is pressed, the motor M is driven in that direction, the valve body moves by a predetermined amount, the limit switches L1 and L2 are switched, the motor M stops, and the water drainage plug V is opened. When the water output V is in the open state and the AND output OP1 of the display unit is 1, if the water pressure falls below a certain value set by the pressure comparison unit due to, for example, water cutoff, the output Pc of the pressure comparison unit and its inverted output P
c ′ outputs low voltage signals inverted to 0 and 1 respectively,
Since P1 is 1, the NAND which is one input of the flip-flop becomes 0, and the output Q of the flip-flop changes from 0 to 1
Flip to As a result, the low water pressure lamp Plq through the transistor is turned on, the AND of the capacitor of the delay unit is set to 1 for a predetermined time until the output Qt 'of the inverter becomes 0, and the latching relay of the latching relay is connected via the transistor. The coil S is energized for a predetermined time, the contact of the power supply relay is switched to the s side, and the DC motor M is driven.
The drain plug V is closed to prevent backflow from there to the upstream water pipe. When the contact point of the power supply relay is switched to the s side, OP1 becomes 0, one input of the flip-flop via the NAND returns to 1, and the output Q is inverted to 1 and held.

After the water cutoff is completed, the water pressure becomes equal to the pressure comparing portion Pc.
, The output Pc of the pressure comparator and its inverted output Pc ′ return to 1 and 0, respectively.
The capacitor of the delay section discharges and the output Pct of the inverter
During the predetermined time until the signal becomes 1, OR, which is the other input of the flip-flop, becomes 0, and the output Q of the flip-flop which has been inverted to 1 returns to 0. As a result, the low water pressure lamp Plq that has been turned on via the transistor is extinguished, and the NOR of the inverter becomes 1 for a predetermined time until the output of the inverter Qt ′ becomes 1 by discharging the capacitor of the delay section,
By energizing the coil R of the latching relay via the transistor for a predetermined time, the contact of the power relay is switched to the r side, the DC motor M is driven, and the water drainage plug V is opened. The delay from the inverted output Pc 'of the pressure comparator is long enough to restore the output Q of the flip-flop, and the delay from the output Q of the flip-flop is long enough to switch the contacts of the power supply relay. I do. One input of the flip-flop is an AND output OP1 of the display unit.
And Pc ', but not the OP1 but the inputs t3 and Pc'.

In the embodiment shown in FIG. 2, when the water pressure falls below a predetermined value when the water tap V is in the open state, the water tap V is closed, and the water in the pipe downstream from the water tap V is drained. Discharge from the mouth to prevent backflow to the drain pipe upstream of the drain plug V,
When the water pressure recovered to a predetermined value or more, the water drainage V returned to the open state, but FIG. 3 shows that the water pressure became lower than the set value and the water drainage V was closed when the water drainage V was in the open state. Drain stopper V
In another embodiment in which the is opened, the corresponding parts are given the same numbers. CT is the output Q of the flip-flop.
Counter with a reset terminal Re connected to
If e is 0, the output Qt does not count the oscillation of the Ck input and the output Qt is 0. If Re becomes 1, the oscillation of the Ck input is counted. Become.

When the water pressure becomes equal to or lower than the set value while the drain plug V is in the opened state, the following operation is performed. That is, the inverted output Pc 'of the pressure comparator becomes 1 and the output Q of the flip-flop is inverted, the contact of the power relay is switched to s to drive in the closing direction, the low water pressure lamp Plq is turned on, and the counter CT is turned on. Reset terminal Re becomes 1 and starts counting oscillation. When a certain time elapses and the count value reaches a certain value, the output Qt changes from 0 to 1. As a result, the output Qt
Until the capacitor of the delay unit is charged, the coil R of the latching relay is energized via the AND and the transistor, and the contact is switched to the r side to open the water drainage plug V. When the capacitor is charged and the output of the inverter becomes 0, the AND with the oscillating unit becomes 0, and the oscillation of the input Ck of the counter stops, but the output Qt remains 1.
When the water pressure recovers above the set value, the output Q of the flip-flop
Returns to 0, the reset terminal Re of the counter becomes 0
And the output Qt becomes 0 without counting the oscillation of the Ck input.
When the output of the inverter becomes 1 when the capacitor of the delay section is discharged and the output of the inverter becomes 1, the Ck input oscillates, but the oscillation is not counted because the reset terminal Re of the counter is 0. As described above, when the water pressure becomes equal to or less than the set value while the drain plug V is open, the drain plug V is driven to the closed state to prevent the backflow of water, and the drain plug V is opened after a certain time determined by the oscillation unit and the counter CT. It returns to the plug state, but this time is made sufficiently longer than the time for discharging the water in the pipe downstream from the water drainage plug V from the drain port.

The low water pressure lamp Plq is lit because the output Q of the flip-flop is inverted and lit when the water pressure falls below a set value while the water drainage plug V is open, so that the pressure sensor P is turned on. Even if it is installed on the downstream pipe instead of the upstream side of the drain plug V of FIG. 1, it does not light up at a low pressure after the water is drained by pushing the closing switch CL, and when the water pressure falls below the set value as shown in FIG. When the drain valve V is closed and returned to the open state after a certain period of time, the low water pressure lamp P
1q is turned on when the water pressure is equal to or lower than the set value when the water drainage plug V is in the open state, and is turned off after the water pressure recovers.

[0021]

As described above, when the water is normally warm, the open water tap is closed, and when there is a possibility that the water may freeze due to cold weather, the water tap is closed and the water in the downstream pipe is drained to freeze. When the water pressure drops from a normal value due to water cutoff or the like, the closed state is maintained and the water in the downstream pipe is drained to reliably prevent the backflow of water to the upstream.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

FIG. 2 is a circuit diagram showing another embodiment of the present invention.

FIG. 3 is a circuit diagram showing another embodiment of the present invention.

[Explanation of symbols]

 Vc Control power supply Vd Driving power supply M Motor V Water drainage P Pressure sensor Pc Pressure comparator Pc 'Pc inverted output Pct Pc's delayed inverted output OP Opening switch CL Closing switch Op Opening lamp Cl Closing lamp OP1 AND on display Output Q Flip-flop output CT counter Ck CT input Qt CT output Re CT reset terminal S, R Latching relay coil s, r Latching relay contact T1, T2, T3 Display input t1, t2, t3 Display Unit input Pl, Plq Low water pressure lamp D1, D2 Diode L1, L2 Limit switch

Claims (3)

[Claims] 1. A DC motor that opens and closes a water drain valve is driven from one side to the other by a DC power source whose polarity is changed by turning on / returning one of two operation switches. In the drive unit of the water tap that stops when it detects that it has become a state, by outputting a signal when the pressure falls below a certain level via a pressure sensor that converts a continuously changing pressure into an electric signal And a control device for the water tap having a pressure switch for outputting the polarity of the DC power supply so as to drive the water tap in the closing direction. 2. A switch for outputting a polarity of a DC power supply so as to output a signal for a predetermined time after a predetermined time has elapsed after the water drainage stopper has reached a predetermined pressure or less in an opened state and to drive the water drainage stopper in the opening direction. A control device for a water drainage plug having the pressure switch according to claim 1, comprising: 3. A water drainage plug having a pressure switch according to claim 1, further comprising a low water pressure lamp which conducts when the pressure of the water drainage stopper becomes lower than a predetermined pressure in an open state, and shuts off when the water recovery becomes higher than the predetermined pressure. Control device.