JPS63248997A - Automatic water supplying device and control thereof - Google Patents

Abstract

PURPOSE:To obtain the uniform operation time and the number of times of operation of a pump by controlling the parallel operation of the pump certainly with high precision in correspondence with the supplied water quantity by comparing the signal supplied from a motor detecting means with the parallel operation control value. CONSTITUTION:As for an automatic water feeding device, a pump 1 equipped with a motor 1a is connected in parallel, and a pressure tank 8 is connected to the discharge side of the pump 1, and a control part 9 controls the operation of the pump by the signal supplied from a pressure detecting means 7. The operation state of the motor 1a is detected by an electric power detecting part (motor detection means) 10, and a calculation part 11a calculates the parallel operation control valve by the signal supplied from the electric power detection part 10 immediately after the start of the single operation of the pump 1, and a comparison part 11b compares said control value with the electric power value detected by the detecting means 10, and the parallel operation of the pump 1 is controlled. Therefore, the start or stop of the parallel operation can be surely controlled with high precision in correspondence with the supplied water quantity, and the dimension of the pressure tank can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic water supply device and a control method thereof, and more particularly to an automatic water supply device in which pumps are connected in parallel and a control method thereof.

[Conventional technology]

In the conventional automatic water supply system of this kind, as shown in FIG. 11, pumps 1' having motors la' are connected in parallel, a pressure tank 8' is connected to the discharge side of the pumps 1', and the pumps 1'
A pressure switch 7' is provided on the discharge side of the pump 1', and a control section 9' is provided for controlling the start or stop of operation of the pump 1' in response to a signal from the pressure switch 7'.

The operation of this automatic water supply device will be explained with reference to FIG.

Figure 12 shows the pump characteristics diagram, with water supply ff1Q on the shaft,
The vertical axis shows pressure H. Hl represents the water supply amount-pressure curve when the pump 1' is operated independently. Hz' indicates the water supply amount-pressure curve of parallel operation of pump 1'. R1 and rl indicate the load curve of pump 1.

When both pumps 1' are stopped, water starts to be supplied from the faucet 6a', and the pressure in the pressure tank 8' decreases to the independent operation start pressure Pon (point a' of H1'), the pressure switch 7' is turned on. When closed, the No. 1 pump 1' operates independently. After operation, when the water supply amount decreases and the pressure H1 increases to reach the individual operation stop pressure Pozz (point b' in Hz), the No. 1 pump 1 stops.

After the above-mentioned operation of No. 1 pump 1, the water supply amount increases and the pressure H
1 and the motor 1a of the No. 1 pump 1 reaches the parallel operation starting pressure Pon' (point C' of Hl), the No. 2 pump 1
also follow and drive. Parallel operation of pump 1 is performed at the intersection d of its load curve R1' and water supply amount-pressure curve Ht'.
’ will be operated.

In this state, the water supply iQ from the faucet 6a' decreases and the parallel operation release pressure Pozz (point f' of I4t')
When this happens, one of the pumps 1 stops operating and becomes an independent operation. Incidentally, related devices of this type include, for example, Japanese Patent Publication No. 59-720.

[Problems to be Solved by the Invention] In such a conventional automatic water supply device, the pressure on the discharge side of the pump 1 is detected by the pressure switch 7', and parallel operation is controlled by this pressure switch 7'. It was not possible to control the amount accurately.

That is, the pressure on the discharge side of the pump 1' may not catch up with the actual amount of water supplied, such as immediately after the pump 1' starts operating, and may be accompanied by a temporary drop. In particular, the pressure tank 8'
When downsizing, such a temporary pressure drop is likely to occur. A temporary pressure drop occurs and the parallel operation start pressure p
When the pressure drops to 'on', pump 1 starts parallel operation, but since the water supply amount is not actually required to perform parallel operation, the parallel operation release pressure is immediately reached and pump 1 starts operating in parallel.
One of the two stops and becomes a standalone operation. If the amount of water supplied remains unchanged during this independent operation, the pressure will drop again and the follow-up pump 1' will be operated, causing a chattering phenomenon.

Further, in this automatic water supply device, no consideration was given to making the operating time of the pump 1 uniform when the pump 1 is repeatedly operated in parallel and independently.

Furthermore, such an automatic water supply device has a problem in that the rotation speed changes due to changes in the voltage applied to the pump 1, etc., and the amount of water supplied changes accordingly.

[Means for solving problems]

A first means of the present invention is to connect pumps each having a motor in parallel, connect a pressure tank to the discharge side of the pump, provide pressure detection means on the discharge side of the pump, and receive a signal from the pressure detection means. The automatic water supply device includes a control unit that controls the operation of the pump in response to a signal, and further includes a motor detection means for detecting the operating state of the motor, and a signal from the motor detection means immediately after the pump starts operating independently. The control unit includes a calculation unit that calculates a parallel operation control value, and a comparison unit that compares (i) from the motor detection means with the parallel operation control value to control parallel operation of the pump. This automatic water supply device is characterized by:

A second means of the present invention includes a pump having a motor connected in parallel, a pressure tank connected to the discharge side of the pump, a pressure detection means provided on the discharge side of the pump, and a pressure tank connected to the discharge side of the pump, a motor detection means for detecting the operating state;
a control unit that controls the operation of the pump in response to a signal from the pressure detection means, and detects the motor immediately after starting independent operation of the pump in response to the signal from the pressure detection means; A parallel operation control value is calculated based on the signal from the motor detection means, and then the signal from the motor detection means is constantly compared with the parallel operation control value, and when a predetermined signal is reached, the pump is started to operate in parallel. This is a characteristic feature of a control method for an automatic water supply device.

A third means of the present invention includes a pump having a motor connected in parallel, a pressure tank connected to the discharge side of the pump, a pressure detection means provided on the discharge side of the pump, and a pressure detection means provided on the discharge side of the pump. An automatic water supply device comprising: a control unit that controls operation of the pump in response to a signal from the means;
A motor detection means for detecting the operating state of the motor is provided, a calculation section for calculating a parallel operation control value based on a signal from the motor detection means immediately after the start of independent operation of the pump, and a calculation section for generating a parallel operation control value; a comparison unit that controls the parallel operation of the pumps by comparing a signal with the parallel operation control value; and a position that controls the pumps in the individual operation alternately when the individual operation and the parallel operation of the pumps are repeated. The automatic water supply device is characterized in that the control section is equipped with an attached section.

A fourth means of the present invention includes a pump having a motor connected in parallel, a pressure tank connected to a discharge side of the pump, a pressure detection means provided on the discharge side of the pump, and a pressure detection means provided on the discharge side of the pump. An automatic water supply device comprising: a control unit that controls operation of the pump in response to a signal from the means;
a calculation unit that provides a motor detection means for detecting the operating state of the motor, and calculates a parallel operation control value with a constant water supply amount by calculating based on a signal from the motor detection means immediately after the start of independent operation of the pump; The automatic water supply device is characterized in that the control section includes a comparison section that controls parallel operation of the pumps by comparing a signal from the detection means with the parallel operation control value.

[Effect]

According to this automatic water supply device, the signal (WS
) to calculate the parallel operation control value (won), (W
att) and a motor detection means (1).
a comparison unit (10b) that controls the parallel operation of the pump 1 by comparing the signal (WS) from 0) with this parallel operation control value;
Since the control unit (9) is equipped with the signal (WS) from the motor detection means (10), which corresponds more accurately to the water supply amount (Q) than the pressure, the signal (WS) from the motor detection means (10) becomes the reference signal.
The parallel operation control value calculated from WS) is not directly related to the pressure on the discharge side of the pump (1) and can be set in accordance with the water supply amount (Q). As a result, parallel operation can be accurately and reliably controlled in accordance with the water supply amount (Q). Even if the pressure tank (8) is downsized and a pressure drop that does not correspond to the amount of water supplied temporarily occurs, the pump (1)
) parallel operation never starts.

Moreover, according to this automatic water supply device, when the pumps (1) are repeatedly operated in parallel and individually, the pumps (1) in each individual operation are operated alternately, so that the operating time of each pump (1) is reduced. And the number of operations can be equalized.

Furthermore, according to this automatic water supply device, even if the voltage applied to the motor (1a) of the pump (1) fluctuates and the rotation speed etc. changes, the amount of water supplied by the pump (1) can be kept the same. Therefore, a stable amount of water can be obtained.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 to 10. In FIG. 1, a pump 1 is configured such that an impeller (not shown) of a pump portion 1b is directly connected to a rotating shaft of a motor 1a. A suction pipe 4 is connected to the suction side of the pump 1. The lower end of this suction pipe 4 reaches into the tank water 3. Tank water 3 is separated from the water supply and stored in a tank. A discharge pipe 5 is connected to the discharge side of the pump 1 . The discharge pipe 5 is provided with a valve 5a.

The discharge pipe 5 is connected to a common pipe 6. A large number of branched faucets 6a are provided at the end of the common pipe 6 (only two are shown in FIG. 1). Two pumps 1 are connected in parallel between a tank water 3 and a common pipe 6 via a suction pipe 4 and a discharge pipe 5.

The pump 1 is operated independently or in parallel depending on the amount of water supplied. The discharge pipe 5 of one pump 1 is provided with a pressure switch 7 and a pressure tank 8, which constitute pressure detection means. Note that the pressure detection means may be a pressure sensor instead of the pressure switch 7. When water starts to be supplied from the faucet 6a and the water in the pressure tank 8 is supplied, the pressure in the pressure tank 8 decreases and the pressure switch 7 is closed. The signal from the pressure switch 7 is input to the instruction control section 11 of the control section 9 . The control section 9 has a power detection section 10 that constitutes a motor detection means for detecting the operating state of the motor 1a. This power detection section 10 detects the electric power of each motor 1a, and the detection signal is outputted to an instruction control section 11. The instruction control unit 11 includes a calculation unit 11a that calculates a parallel operation control value by calculating based on the signal from the power detection unit 10 immediately after the pump 1 starts to operate independently;
a comparison unit 10b that compares the signal from the power detection unit 10 with the parallel operation control value to control the parallel operation of the pumps 1; and a pump 1 that operates independently when the individual operation and parallel operation of the pump 1 are repeated. A positioning section 11c is provided for controlling the positions alternately. Signals from the instruction control unit 11 are output to the motors 1a, respectively. Note that the motor detecting means may be a current detecting section or a rotation speed detecting section instead of the power detecting section 10.

In FIG. 2, each motor 1a is connected to one power source 12 in parallel. This power supply circuit has an electromagnetic contactor 1
3 and 14 are connected respectively.

Power supply detection units 10 are connected to the power supply circuits on the side of the power supply 12 from the electromagnetic contactors 13 and 14, respectively. The power detection unit 10 is composed of a coil 15 connected in series to a power supply circuit, a Hall element 16 connected in parallel, and a rectification/smoothing circuit 17 connected to its output side. As a relationship corresponding to the electric power, the electric power and sound power are detected based on the DC voltage value. The output side of the rectifier/smoothing circuit 17 is shown in Figure 2 by ■ and ■.
indicates that the process reaches ■ and ■ in FIG. A phase advance capacitor 18 is connected to the motor 1a. Note that the power detection section 10 may be a current detection section.

In FIG. 3, the instruction control unit 11 is mainly configured with an instruction control element 19 such as a microcomputer. From the power supply 12 to the power transformer 20 - II current/smoothing circuit 21
and v of the instruction control element 19 through the constant pressure circuit 22.
Connected to the DD-vss port. Instruction control element 1
A clock circuit 23 that creates a reference timer of 9 is connected.

Coils 24 and 25 for opening and closing the aforementioned electromagnetic contactors 13 and 14 (FIG. 2) are connected to power source 12 via one circuit three-contact switch 26 and one pole 7a of pressure switch 7.

Inputs to the instruction control element 19 are PIO1 to PIO.

It is performed from P2O and P41. The circuit of the other pole 7b of the pressure switch 7 is connected to Baud 1 to P10.

The boats P40 and P41 have a power detection unit 1 for the motor 1.
The output sides (■ and ■) of 0 are connected via comparators 27 and 28. The D/A converter 29 is connected to the boat P30°P31. P32. The digital value of P33 is converted into an analog value, and a voltage corresponding to the power value to be determined is generated and input to the comparators 27 and 28. Comparators 27 and 28 compare whether the output of the power detection unit 10 of the motor 1a has reached a predetermined value and send the result to the boat P4.
Enter 0.

One side of the zero-cross timing input circuit 30 is connected to the secondary side of the power transformer 2o, and the other side is connected to the boat INT of the instruction control element 19.

A signal is outputted from the ports P20-P21 of the instruction control element 19 at zero-cross timing, and is connected to drive triacs 33 and 34 of switching elements via phototriacs 31 and 32. The triacs 33 and 34 are connected in parallel with the poles to which the coils 24 and 25 of the one-circuit three-contact switch 26 are connected. By switching the 1 circuit 3 contact switch 26,
Regardless of the instruction control signal from instruction control element 19.

Alternatively, even if there is no instruction control signal due to a malfunction, the coils 24 and 2 can be turned on or off by opening and closing one pole 7a of the pressure switch 7.
5 is energized/stopped, and the pump 1 is thereby started/stopped.

The general operation of such an automatic water supply device will be explained with reference to FIG. FIG. 4 shows a pump characteristic diagram, in which the horizontal axis shows the water supply amount Q, and the vertical axis shows the pressure H and the electric power W. Hl indicates a water supply amount-pressure curve when pump 1 is operated independently.

H1' indicates a water supply amount-pressure curve when pump 1 is operated in parallel. Wl indicates the water supply amount-power curve of pump 1. R and rl indicate the load curve of pump 1.

When both pumps 1 are stopped, water starts to be supplied from the faucet 6a, and the pressure in the pressure tank 8 decreases to the independent operation start pressure Pon (point a of Hl), the pressure switch 7 closes and the No. 1 pump 1 drives alone.

After operation, when the water supply amount decreases and the pressure H1 rises to the individual operation stop pressure Pozz (point b of Ht), the No. 1 pump 1 stops. After the above-mentioned operation of the No. 1 pump 1, the water supply amount increases, the pressure H1 decreases, and the motor 1a of the No. 1 pump 1 reaches the parallel operation start power Won (point C of Hl), and the No. 2 pump 1 also follows. drive. Parallel operation of pump 1 is based on its load curve R1 and water supply amount-pressure curve H1'
The vehicle will be operated at the intersection d. In this state, the amount of water supplied from the faucet 6a decreases, causing the motor 1a of the pump 1 to
When the parallel operation cancellation power Wotz (point f of Hl) is reached, the preceding No. 1 pump 1 stops operating, and the following No. 2 pump stops operating.
No. 1 pump will operate independently.

Next, a method of controlling such an automatic water supply device will be explained with reference to FIGS. 5 to 7. FIG. 5 shows the main routine. Den'g12
The process starts by closing the , and initial settings are first performed (500). This initial setting secures parameter areas for F, S, and J in the random access memory on the instruction control element 19, and sets F=O, S=O, and J=O to 'F'.
Determine J. F is a parameter for controlling the No. 1 pump, S is a parameter for controlling the No. 2 pump, and J is a parameter for determining parallel operation. Then,
Waits for the pressure Pon of the pressure switch 7, and when the pressure reaches POn, a subroutine is reached in which the pump 1 is operated (510).
.

FIG. 6 shows the operating subroutine. In the operation subroutine, first determine whether the F parameter is 1 (600).
, in the case of F=1, No. 1 pump 1 is operated in advance (61
0), if F≠1, No. 2 pump 1 is operated in advance (
620), the motor 1a of the pump 1 operated immediately after that
630), this detected power Ws
The parallel operation starting power W o n and the parallel operation canceling power W o t i are calculated and determined based on the
), return to the main routine. After returning to the main routine, the program jumps to the parallel control subroutine (530).

FIG. 7 shows the parallel control subroutine. In the parallel control subroutine, the electric power Ws of the motor 1a of the pump 1 in operation is
is detected (710), this electric power Ws is compared with the parallel operation starting electric power Won (720), and if Ws≧W o n, the pump 1 that is operating independently is determined using the F parameter (730). If the F parameter is F=1, it will follow the No. 2 pump 1 that is not in operation and start operating 74
0), if F≠1, the pump No. 1 that is not in operation will follow and operate (750), and after obtaining L, set the J parameter to "1" to indicate that parallel operation is in progress. 760), returning to the main routine. The aforementioned motor 1a
The detected power W5 and the set power Won are compared (720
), if Ws < Won, compare whether the F parameter is J=1 (770), if J≠1 (during independent operation), return to the main routine, and if J=1 (during parallel operation), check the detected power Ws and the parallel operation cancellation power W o t (771). If Ws>W o z x, the process returns to the main routine, and if Ws≦W o t n, the F parameter is determined (772).

If the F parameter is F=1, the No. 1 pump 1 which is being operated in advance is stopped (773), and if F≠1, the No. 2 pump 1 which is being operated in advance is stopped (774). Then F
Swap the state of the parameter and the state of the S parameter ("
1'' and reverse rOJ), and change the leading and trailing positions (775).

Thereafter, the J parameter is set to rOJ to indicate cancellation of the parallel operation (776), and the process returns to the main routine.

After this, in the main routine, the pressure P of the pressure switch 7 is
It waits for oti (540) and cycles through the parallel control subroutine until the pressure reaches PO11. Pressure P. □.

If so, the pump 1 in operation is stopped (550).

Next, after changing the state of the F parameter and the state of the S parameter (inverting "1" and "0") and changing the leading and following positions (560), the pressure Po of the pressure switch 7o is changed.
Wait for n (510).

FIG. 8 shows a time chart showing an example of the operating state of such an automatic water supply device. As is clear from this figure, it can be seen that the operating times of the No. 1 pump and the No. 2 pump are average.

In this control method, the point that control is possible even when the rotational speed of the motor 1a of the pump 1 changes will be explained with reference to FIGS. 9 and 10. FIG. 9 shows a pump characteristic diagram when the rotational speed of the motor 1a of the pump 1 changes, with the horizontal axis showing the water supply amount Q, and the vertical axis showing the pressure H and the electric power W. H
1 to H3 are water supply amount-pressure characteristic curves for independent operation of pump 1, where the rotation speed change ratio is rlJ, ro, 95'', ro, 9
” is shown below. H engineering r~Ha' is the water supply amount-pressure characteristic curve of parallel operation of pump 1, and the change ratio of rotation speed is rlJ
, ro, 95J and ro, 9J are shown.

W□ to W3 are water supply amount-power characteristic curves of pump 1.

The change ratio of rotation speed is rlJ, ro, 95J, ro, 9J
The case is shown below. R1-R3 is a load curve, showing cases where the rotational speed change ratio is rlJ, ro, 95J, ro, 9J. rl indicates a load curve. The pressure decreases to the independent operation start pressure Pon, the pressure switch 7 closes, and the pump 1
The electric power of the motor 1a of the pump 1 immediately after being operated independently is W.
s 1 and is determined based on this detected power Ws. Wont is the power to start parallel operation, and W is power to cancel parallel operation. Let it be ttl. The amount of water supplied at each of these points is Q s 1
* Let Q o n and Q o z t be.

W2 + Wa at parallel operation start water supply amount Q o n
Let the parallel operation start power of WonzHWona be WonzHWona, and let the parallel operation release power of W2 and Wa at the parallel operation release water supply amount Qo□ be Woix2. Wants and H
The power to start independent operation of pump 1 at 2°H3 is WS2
゜Wsa.

Therefore, the detected electric power Wsll WS2 of the motor 1a of the pump 1 immediately after the independent operation is determined. Wsa and parallel operation start power W
The relationship with Only WOnZ + Wona or the parallel operation cancellation power Woazt, Wo,, z, Wonts is linear as shown in FIG. 8, and is expressed by the following equation.

Won=KtWs+2-(1)Wa
it = KsWs + K4 −
(2) (K 1 to 4 are constants) Therefore, the parallel operation start power W is determined by the detected power Ws. n
and the parallel operation cancellation power W ox i can be easily calculated.

According to this automatic water supply device, the parallel operation start electric power W is calculated based on the signal Ws from the electric power detection unit 10 immediately after the pump 1 starts its individual operation. n or parallel operation cancellation power wait
The signal W from the arithmetic unit 11a and the power detection unit 10 that generates
Since the instruction control unit 11 is equipped with a comparison unit 10b that controls the start or stop of the parallel operation of the pump 1 by comparing the parallel operation start power W o n or the parallel operation cancellation power W o t t , the pressure The detected power Ws that corresponds to the water supply amount Q with high precision compared to the reference signal is the reference signal, and the parallel operation starting power W o calculated from this detected power Ws
n or parallel operation cancellation power W o x t is pump 1
It is not directly related to the discharge side pressure, and can be set in accordance with the water supply amount Q. As a result, the water supply f
It is possible to accurately and reliably control the start or stop of parallel operation in accordance with Q. Even if the pressure tank 8 is downsized and a pressure drop that does not correspond to the amount of water supply occurs temporarily, the pumps 1 will not start running in parallel.

Further, according to this automatic water supply device, when the parallel operation and individual operation of the pumps 1 are repeated, the pumps 1 in each individual operation are operated alternately, so that the operation time and number of operations of each pump 1 are equalized. can do.

Furthermore, according to such an automatic water supply device, even if the voltage applied to the motor 1a of the pump 1 fluctuates and the rotation speed etc. changes,
Since the water supply amount of the pump 1 can be made the same, a stable water supply amount can be obtained.

〔Effect of the invention〕

According to the present invention, firstly, it is possible to provide an automatic water supply device and a control method thereof that can accurately and reliably control parallel operation in accordance with the amount of water supply. Second, it is possible to provide an automatic water supply device that can further equalize the operating time and number of pump operations. Third
It is possible to provide an automatic water supply device that can obtain a stable amount of water supply.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the automatic water supply device of the present invention, FIG. 2 is an electric circuit diagram showing the motor detection means of the automatic water supply device, FIG. 3 is an electric circuit diagram showing instruction control of the automatic water supply device, and FIG. Figure 4 is a pump characteristic diagram of the automatic water supply system, and Figure 5 is a flowchart 1 showing the main routine of the control method of the automatic water supply system.
- Figure 6 is a flowchart showing the operating subroutine in the main routine, Figure 7 is a flowchart 1 to 1 to Figure 7 showing the parallel control subroutine in the main routine, and Figure 8 is a flowchart showing the operation subroutine in the main routine. Fig. 9 is a pump characteristic diagram explaining changes in the pump rotation speed of the automatic water supply device, Fig. 1o is a characteristic diagram of parallel operation control power of the same pump characteristics, and Fig. 11 is a conventional A configuration diagram of the automatic water supply device, and FIG. 12 is a pump characteristic diagram of the automatic water supply device. 1... Pump, 1a... Motor, 6a... Faucet,
7... Pressure switch (pressure detection means), 8... Pressure tank, 9... Control section, 10... Power detection section (motor detection means), 11... Instruction control section, lla...・Arithmetic part, llbF$, + mouth 3rd mouth 26-cums, itte 31.32 Futotora 4 finished paddy rice b no meg prisoner Zchi small ° nf 0
---one σ
FF No. 10 (0 Ward No. [(Leap 1″ 1 procedural amendment (voluntary)

Claims (1)

[Claims] 1. Pumps having motors are connected in parallel, a pressure tank is connected to the discharge side of the pump, a pressure detection means is provided on the discharge side of the pump, and a signal from the pressure detection means is In the automatic water supply device, the automatic water supply device is equipped with a control unit that controls the operation of the pump based on the operation of the pump. and a comparison unit that compares the signal from the motor detection means with the parallel operation control value to control parallel operation of the pumps. Automatic water supply device. 2. The automatic water supply device according to claim 1, in which the pressure detection means is a pressure switch. 3. The automatic water supply device according to claim 1, wherein the motor detection means is a power detection section that detects the power of the motor. 4. The automatic water supply device according to claim 1, which serves as a control unit including a microcomputer. 5. The automatic water supply device according to claim 1, in which the parallel operation control value is used as the parallel operation start value. 6. The automatic water supply device according to claim 1, wherein the parallel operation control value is a parallel operation start value and a parallel operation release value. 7. The automatic water supply device according to claim 5 or 6, wherein the parallel operation start value is a value corresponding to a larger water supply amount than when the individual pump starts operating. 8. A pump having a motor connected in parallel, a pressure tank connected to the discharge side of the pump, a pressure detection means provided on the discharge side of the pump, and a motor detection device for detecting the operating state of the motor. and a control section for controlling the operation of the pump in response to a signal from the pressure detection means, and immediately after starting the independent operation of the pump in response to the signal from the pressure detection means. A parallel operation control value is calculated based on the signal from the motor detection means, and then the signal from the motor detection means is constantly compared with the parallel operation control value, and when the signal reaches a predetermined value, the parallel operation of the pump is started. A method for controlling an automatic water supply device, characterized in that: 9. A pump having a motor connected in parallel, a pressure tank connected to the discharge side of the pump, a pressure detection means provided on the discharge side of the pump, and a signal received from the pressure detection means; In an automatic water supply device comprising a control unit for controlling operation of the pump, a motor detection means for detecting the operating state of the motor is provided, and the automatic water supply device is configured to perform calculation based on a signal from the motor detection means immediately after the start of independent operation of the pump. a computation unit that generates a parallel operation control value based on the motor detection means; a comparison unit that compares the signal from the motor detection means with the parallel operation control value to control parallel operation of the pump; and a comparison unit that controls the parallel operation of the pump. An automatic water supply device characterized in that the control section includes a positioning section that alternately controls a pump in single operation during repetition. 10. A pump having a motor connected in parallel, a pressure tank connected to the discharge side of the pump, a pressure detection means provided on the discharge side of the pump, and receiving a signal from the pressure detection means In an automatic water supply device comprising a control unit for controlling operation of the pump, a motor detection means for detecting the operating state of the motor is provided, and the automatic water supply device is configured to perform calculation based on a signal from the motor detection means immediately after the start of independent operation of the pump. The control unit includes a calculation unit that generates a parallel operation control value with a constant water supply amount, and a comparison unit that compares a signal from the motor detection means with the parallel operation control value to control parallel operation of the pumps. An automatic water supply device characterized by: