JPH11173291A - Automatic water supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the suspension of water supply even in the malfunction of electronic components such as an inverter or the like under a condition that the pressure and the capacity of a pump is less than the predetermined values and the frequency is less than the maximum frequency by instantaneously stopping an electric motor when the abnormality is judged and then operating the electric motor again. SOLUTION: A control part 16 comprises an output frequency detecting part 16c for detecting the operation frequency of motor 15 m, an operation current detecting part 16d for detecting the operation current of the motor 15 m, and a timer 16e for counting the time of the malfunction of an inverter 16b. The malfunction of the inverter 16b is judged in a case when the time under the conditions that discharge pressure of a pump 15 < predetermined pressure, capacity < predetermined capacity, operation frequency < maximum operation frequency and operation current < predetermined current, is above the predetermined time when the pump is automatically operated under the target pressure and the constant control. On this occasion, the pump 15 is forcibly stopped, and then the pump 15 is restarted after a specific time. Whereby the suspension of water supply can be prevented even in the malfunction of the inverter 16b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic water supply apparatus for automatically operating a pump using an inverter, the automatic water supply having a protection function for preventing the pump from malfunctioning due to noise from a power supply or air. Related to the device.

[0002]

2. Description of the Related Art Conventionally, a pump used in an automatic water supply device has been operated at a commercial frequency. However, in recent years, a pump used in an automatic water supply device is controlled by an inverter, and the rotation speed of the pump is controlled to keep the discharge pressure of the pump constant. in this way,
By controlling a pump used in the automatic water supply device by an inverter, the automatic water supply device is operated with energy saving.

[0003]

As described above, in order to control the pump used in the automatic water supply device by the inverter,
The automatic water supply device is equipped with various electronic components and a microcomputer. In the case where the microcomputer is mounted as described above, removing external noise becomes a problem. Therefore, a device for removing external noise has been devised.

[0004] However, if noise enters for some reason, the inverter may malfunction. In this way, even if the inverter malfunctions, it is necessary to prevent water interruption as much as possible.

The present invention has been made in view of the above points, and has as its object to provide an automatic water supply apparatus capable of preventing water cutoff even when an electronic component such as an inverter mounted on the apparatus malfunctions. Is to provide.

[0006]

An automatic water supply apparatus according to claim 1 includes a variable speed operation means for operating a motor for driving a pump at a variable speed, a pressure detection means for detecting a discharge pressure of the pump, and the pump. In the automatic water supply device comprising a flow rate detecting means for detecting a flow rate discharged from the air supply means and an output frequency detecting means for detecting an output frequency of the variable speed operating means, the variable speed operating means causes the motor to operate at a variable speed. A constant target pressure control means for controlling the discharge pressure of the pump to be a constant target pressure, and when the constant target pressure control is performed by the constant target pressure control means, a pressure equal to or less than a set pressure by the pressure detection means. Is detected, and the flow rate below the set flow rate is detected by the flow rate detection means, and the frequency is less than the maximum frequency by the output frequency detection means Abnormality detection means for determining that an abnormality has occurred when a frequency is detected; and retry operation means for immediately stopping and restarting the motor when the abnormality detection means determines that an abnormality has occurred. Features.

In the automatic water supply apparatus according to a second aspect, the abnormality detecting means according to the first aspect is configured such that when the target pressure constant control is performed by the target pressure constant control means, the pressure detecting means detects a pressure lower than a set pressure. The detected flow rate is detected by the flow rate detection means to be equal to or less than a set flow rate, the output frequency detection means is to detect a frequency of less than the maximum frequency, and the operation current of the variable speed operation means is detected to be smaller than the set current. Is determined to be abnormal when the error occurs.

According to a third aspect of the present invention, there is provided an automatic water supply apparatus, wherein the retry operation means is driven after a set time has elapsed after an abnormality is detected by the abnormality detection means according to any one of the first and second aspects. Features.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of the automatic water supply device. In FIG. 1, reference numeral 11 denotes a well. Water 12 is stored in the well 11.

One end of a water supply pipe 13 is provided so as to be immersed in the water 12 of the well 11. The other end of the water supply pipe 13 is connected to a suction port of a pump 15 via a check valve 14.

The rotation of the pump 15 is controlled by a motor 15m. The operating frequency of the motor 15m is controlled by an inverter (variable speed operating means) 16b in the control unit 16.

A water supply pipe 18 provided with a flow rate sensor (FS) 17 is connected to a discharge port of the pump 15. The flow rate sensor 17 detects the flow rate I discharged from the discharge port of the pump 15.

A pressure tank 19 is connected to the water supply pipe 18 at a position downstream of the flow sensor 17. Further, a pressure sensor (PS) 20 is further connected to a position where the pressure tank 19 is connected to the water supply pipe 18. The pressure sensor 20 detects the discharge pressure P of the pump 15.

The control section 16 is mainly composed of a CPU 16a and an inverter 16b. Further, the control unit 16 determines an output frequency detecting unit 16c for detecting the operating frequency of the motor 15m, an operating current detecting unit 16d for detecting the operating current of the motor 15m, and a time during which the inverter 16b is malfunctioning. A timer 16 for counting is provided.

The CPU 16a performs the processing shown in the flowchart of FIG. Next, the operation of the embodiment of the present invention configured as described above will be described with reference to the flowchart of FIG.

First, automatic operation is performed under the target pressure constant control (step S1). That is, when the discharge pressure P of the pump 15 detected by the pressure sensor 20 becomes equal to or lower than the starting pressure Ps, the operation of the pump 15 is started. The operating frequency of the pump 15 is determined by the inverter 16a so that the discharge pressure P of the pump 15 becomes the target pressure Pt.

The flow rate I detected by the flow rate sensor 17 is
Is smaller than the stop flow rate Io, a process of stopping the pump 15 is performed. In this way, automatic operation control is performed so that the discharge pressure P of the pump 15 becomes the target pressure Pt.

By the way, during the automatic operation control, the control after step S2 is performed. First, the discharge pressure P of the pump 15 detected by the pressure sensor 20 is detected (Step S2).

Then, the discharge pressure P of the pump 15 detected by the pressure sensor 20 is compared with a set pressure Ppre (<Pt) (step S3). Next, the flow rate I is detected by the flow rate sensor 17 (step S4).

The flow rate I and the set flow rate Ipre (>)
Io), that is, it is determined whether or not "I <Ipre" (step S5). If “YES” is determined in the determination in step S5, the output frequency detecting unit 1
6c, the operation frequency f is detected (step S
6).

The operating frequency f is the set frequency,
That is, the maximum operating frequency fmax is compared, that is, it is determined whether or not "f <fmax" (step S7).
If the determination in step S7 is "YES", the operation current detector 16d outputs the motor 15
An operating current i of m is detected (step S8).

The operation current i is compared with the set current ipre, that is, it is determined whether "i <ipre" (step S9). If "YES" is determined in the determination in step S9, the time T during which the timer 16e malfunctions is counted (step S10).

Then, the malfunctioning time T is compared with the set time Tpre, that is, it is determined whether "T <Tpre" (step S11). If it is determined as “YES” in the determination in step S11, the process returns to step S2 described above.

On the other hand, if the determination in step S11 is "NO", the pump 15 is forcibly stopped (step S12). Then, after the pump 15 is forcibly stopped, a process of restarting the pump 15 is performed after a certain period of time (step S13). Hereinafter, the processing after step S1 is started.

As described above, when the automatic operation is performed under the constant target pressure control, the operation is performed at the discharge frequency P <the set pressure Ppre, the flow rate I <the set flow rate Ipre, the operation frequency f <fmax, and the discharge pressure P of the pump 15. If the current i <imax, it is determined that the inverter 16b is malfunctioning, and the pump 15
, The pump 15 is restarted after a certain period of time, so that even if the inverter 16b malfunctions, water interruption can be avoided. When it is determined “NO” in steps S3, S5, S7, and S9, the process returns to step S2.

[0026]

According to the first and second aspects of the present invention, when a malfunction occurs, the retry operation is performed, so that the occurrence of water cutoff can be reliably prevented. According to the third aspect of the invention, when the malfunctioning time continues for the set time, the retry operation is performed, so that the occurrence of water cutoff can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an automatic water supply device according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of one embodiment of the present invention.
Chart.

[Explanation of symbols]

 Reference numeral 15: pump, 15m: motor, 16: control unit, 16a: CPU, 16b: inverter, 17: flow sensor, 18: water supply pipe, 19: pressure tank, 20: pressure sensor.

Claims (3)

[Claims] A variable speed operating means for operating a motor for driving the pump at a variable speed; a pressure detecting means for detecting a discharge pressure of the pump; a flow detecting means for detecting a flow rate discharged from the pump; An automatic water supply device comprising output frequency detection means for detecting the output frequency of the variable speed operation means, wherein the variable speed operation means causes the motor to operate at a variable speed so that the discharge pressure of the pump becomes a constant target pressure. When the target pressure constant control is being performed by the target pressure constant control means, a pressure equal to or less than a set pressure is detected by the pressure detecting means, and a flow rate equal to or less than the set flow rate is detected by the flow rate detecting means. When the output frequency is detected and a frequency lower than the maximum frequency is detected by the output frequency detecting means, the abnormality is determined to be abnormal. And detecting means, the abnormality when an abnormality is judged by the detecting means, an automatic water supply device being characterized in that includes a retry operation means for operating again instantly stops the motor. 2. The pressure detecting device according to claim 2, wherein when the target pressure constant control unit performs the target pressure constant control, the abnormality detecting unit detects a pressure equal to or less than a set pressure,
And the set flow rate or less is detected by the flow rate detection means,
When the output frequency detecting means detects a frequency whose frequency is lower than the maximum frequency and detects that the operating current of the variable speed operating means is smaller than a set current, it is determined that the output is abnormal. Item 6. The automatic water supply device according to Item 1. 3. The automatic water supply device according to claim 1, wherein the retry operation unit is driven after a set time from the detection of the abnormality by the abnormality detection unit.