JP3614630B2 - Automatic water supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic water supply apparatus that automatically operates a pump using an inverter and has a protective function for preventing the pump from malfunctioning due to noise from a power source or air.
[0002]
[Prior art]
Conventionally, pumps used in automatic water supply devices have been operated at commercial frequencies. However, in recent years, a pump used in an automatic water supply apparatus is controlled by an inverter to control the rotational speed of the pump so as to keep the discharge pressure of the pump constant. In this way, the automatic water supply apparatus is operated with energy saving by controlling the pump used in the automatic water supply apparatus with an inverter.
[0003]
[Problems to be solved by the invention]
Thus, in order to perform inverter control of the pump used in the automatic water supply apparatus, the electronic water supply apparatus is equipped with various electronic components and a microcomputer.
Thus microcomputer - in case of mounting the motor is because removing the external noise that Do question, devised to eliminate external noises have been made.
[0004]
However, when noise enters for some reason, it is assumed that the inverter malfunctions.
In this way, even if the inverter malfunctions, it is necessary to prevent water cut off as much as possible.
[0005]
The present invention has been made in view of the above points, and an object of the present invention is to provide an automatic water supply apparatus that can prevent water shutoff even when an electronic component such as an inverter mounted on the apparatus malfunctions. There is.
[0006]
[Means for Solving the Problems]
An automatic water supply apparatus according to claim 1 includes: variable speed operation means for variable speed operation of an electric motor that drives a pump; pressure detection means for detecting a discharge pressure of the pump; and a flow rate for detecting a flow rate discharged from the pump. In an automatic water supply apparatus comprising a detection means and an output frequency detection means for detecting an output frequency of the variable speed operation means, the discharge pressure of the pump is targeted by causing the variable speed operation means to operate the electric motor at a variable speed. A target pressure constant control means for controlling the pressure to be constant and stopping the electric motor when the flow rate detected by the flow rate detection means is smaller than the stop flow rate;
When the target pressure constant control is performed by the target pressure constant control means, the pressure detection means detects a set pressure lower than the target pressure, and the flow rate detection means detects a set flow rate lower than the stop flow rate. An abnormality detecting means for detecting an abnormality when a frequency lower than the maximum frequency is detected by the output frequency detecting means, and when the abnormality detecting means determines that an abnormality has occurred, the motor is instantaneously And retry operation means for stopping and restarting operation.
[0007]
According to a second aspect of the present invention, there is provided the automatic water supply apparatus according to the first aspect, wherein the abnormality detecting means has a set pressure smaller than the target pressure by the pressure detecting means when the target pressure constant control is performed by the target pressure constant control means. The following is detected, and the flow rate detection means detects a flow rate less than the set flow rate greater than the stop flow rate , the output frequency detection means detects a frequency less than the maximum frequency, and the operating current of the variable speed operation means is set. When it is detected that the current is smaller than the current, it is determined that the current is abnormal.
[0008]
An automatic water supply apparatus according to a third aspect is characterized in that the retry operation means is driven after a set time after an abnormality is detected by the abnormality detection means according to any one of the first or second aspects. .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an overall configuration diagram of an automatic water supply apparatus. In FIG. 1, 11 is a well. Water 12 is stored in the well 11.
[0010]
One end of a water supply pipe 13 is installed 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 the pump 15 via a check valve 14.
[0011]
The rotation of the pump 15 is controlled by a motor 15m.
The operation frequency of the motor 15m is controlled by an inverter (variable speed operation means) 16b in the controller 16.
[0012]
Further, a water supply pipe 18 in which a flow sensor (FS) 17 is interposed is connected to the 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.
[0013]
In the water supply pipe 18, a pressure tank 19 is connected to a downstream position of the flow sensor 17.
Furthermore, 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.
[0014]
By the way, the control part 16 is comprised centering on CPU16a and the inverter 16b. Further, the control unit 16 determines the time during which the output frequency detecting unit 16c for detecting the operating frequency of the motor 15m, the operating current detecting unit 16d for detecting the operating current of the motor 15m, and the inverter 16b are malfunctioning. A timer 16 for counting is provided.
[0015]
The CPU 16a performs 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.
[0016]
First, automatic operation is performed with constant target pressure 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 operation 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.
[0017]
Further, when the flow rate I detected by the flow rate sensor 17 becomes smaller than the stop flow rate Io, processing for 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.
[0018]
By the way, during the automatic operation control as described above, 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).
[0019]
Then, the discharge pressure P of the pump 15 detected by the pressure sensor 20 is compared with the set pressure Ppre (<Pt) (step S3).
Next, the flow rate sensor 17 detects the flow rate I (step S4).
[0020]
Then, the flow rate I is compared with the set flow rate Ipre (> Io), that is, it is determined whether “I <Ipre” is satisfied (step S5).
When it is determined as “YES” in the determination in step S5, the operation frequency f is detected in the output frequency detection unit 16c (step S6).
[0021]
Then, it is determined whether this operating frequency f is compared with the set frequency, that is, the maximum operating frequency fmax, that is, “f <fmax” (step S7).
If it is determined as “YES” in step S7, the operating current i of the motor 15m is detected by the operating current detector 16d (step S8).
[0022]
The operating current i and the set current ipre are compared, 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 is malfunctioning is counted (step S10).
[0023]
Then, the malfunctioning time T is compared with the set time Tpre, that is, it is determined whether or not “T <Tpre” (step S11).
If it is determined as “YES” in the determination in step S11, the process returns to the process in step S2.
[0024]
On the other hand, when it is determined as “NO” in the determination in step S11, a process for forcibly stopping the pump 15 is performed (step S12).
Then, after the pump 15 is forcibly stopped, a process for restarting the pump 15 is performed after a predetermined time (step S13). Thereafter, the processing after step S1 is started.
[0025]
As described above, when automatic operation is performed with the target pressure constant control, the discharge pressure P of the pump 15 <the set pressure Ppre, the flow rate I <the set flow rate Ipre, the operation frequency f <fmax, and the operation current i < If imax, it is determined that the inverter 16b is malfunctioning, and the pump 15 is forcibly stopped, and then the pump 15 is restarted after a certain period of time. Even when it operates, it is possible to avoid water outage.
If “NO” is determined in steps S3, S5, S7, and S9, the process returns to step S2.
[0026]
【The invention's effect】
According to the first and second aspects of the present invention, when a malfunction occurs, the retry operation is performed, so that it is possible to reliably prevent the occurrence of water outage.
According to the third aspect of the present invention, when the malfunctioning time continues for the set time, the retry operation is performed, so that it is possible to reliably prevent the occurrence of water breakage.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an automatic watering apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart for explaining the operation of the embodiment of the present invention.
[Explanation of symbols]
15 ... pump,
15m ... motor,
16 ... control part,
16a ... CPU,
16b: Inverter,
17 ... Flow sensor,
18 ... water supply piping,
19 ... pressure tank,
20: Pressure sensor.

Claims (3)

A variable speed operation means for variable speed operation of an electric motor for driving the pump, a pressure detection means for detecting a discharge pressure of the pump, a flow rate detection means for detecting a flow rate discharged from the pump, and a variable speed operation means. In an automatic water supply apparatus comprising an output frequency detection means for detecting an output frequency,
The variable speed operation means controls the electric motor to operate at a variable speed so that the pump discharge pressure is controlled to be a constant target pressure, and the electric motor is stopped when the flow rate detected by the flow rate detection means becomes smaller than the stop flow rate. A target pressure constant control means,
When the target pressure constant control is performed by the target pressure constant control means, the pressure detection means detects a set pressure lower than the target pressure, and the flow rate detection means detects a set flow rate lower than the stop flow rate. An abnormality detecting means for detecting an abnormality when a frequency less than the maximum frequency is detected by the output frequency detecting means;
An automatic water supply apparatus comprising: a retry operation means for stopping the electric motor instantaneously and operating again when it is determined that the abnormality is detected by the abnormality detection means. The abnormality detection means detects a set pressure lower than the target pressure by the pressure detection means when the target pressure constant control is performed by the target pressure constant control means, and the flow rate detection means detects the stop flow rate. Abnormal when a larger set flow rate or less is detected, the output frequency detecting means detects a frequency that is less than the maximum frequency, and the operating current of the variable speed operating means is smaller than the set current. The automatic water supply apparatus according to claim 1, wherein the automatic water supply apparatus is determined. 3. The automatic water supply apparatus according to claim 1, wherein the retry operation unit is driven after a set time after an abnormality is detected by the abnormality detection unit.

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