JP3165741B2 - Control method of automatic water supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method of an automatic water supply apparatus having a flow detection unit for sending a stop signal in a region below a stop flow rate, and more particularly to an automatic water supply apparatus using a chattering pulse of the flow detection unit. Control method.

[0002]

2. Description of the Related Art In an ordinary automatic water supply device, an accumulator is provided to reduce the starting frequency of a pump, and the stop flow rate of a flow rate detection unit is reduced (for example, 10 l / min).
) It has been set. Therefore, when the amount of water supply is small (20 to 30 l / min) at night or the like, even if a plurality of pumps are provided, there are few opportunities for alternate operation, and the original function of improving the reliability by averaging the operation time. Is difficult to demonstrate. It is impractical to set a large stop flow rate (30 l / min) because the start frequency increases.

On the other hand, turbulence is likely to occur due to the high flow velocity in a region where the amount of supplied water is large, and there is a possibility that the output of the flow rate detection section which should be maintained in a stable state during operation is in a chattering state in which a pulse train is generated. As a result, there is a risk that the operation should be stopped in a high flow rate region that must be avoided. Further, when the flow rate detecting section is provided near a curved pipe section or the like (marked by X in FIG. 1), chattering may occur even in a small flow rate range.

[0004]

In order to avoid the influence of the chattering, the shape of the flow path and the mounting position of the flow detecting unit are appropriately changed, or a flow detecting unit having a detecting end which is unlikely to cause chattering is used. Although it is possible, there is no way to expect a sufficient effect for the required cost.

The present invention has been made based on the above circumstances, and focuses on the fact that the larger the flow rate, the narrower the pulse width of the chattering pulse of the flow rate detection unit becomes. It is an object of the present invention to provide a control method of an automatic water supply device that can improve reliability by averaging.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an automatic water supply device having a flow detecting unit for sending a stop signal in a region equal to or less than a stop flow, wherein a chattering pulse of the flow detecting unit in a region exceeding the stop flow is provided. It is a second stop signal selectively set in relation to the pulse width.

[0007]

In the above configuration, since the second stop signal is selectively set in relation to the chattering pulse width, the stop flow rate corresponding to the second stop signal is variably set in relation to the pump operation time. As a result, the longer the operation time, the larger the flow rate is stopped.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to an embodiment shown in FIGS. In FIG. 1, two sets of pumps 1 and 2 are provided with electric motors 3 and 4, and the suction side is guided to a water tank 5, and the discharge side is joined via flow rate detectors 6 and 7 and check valves 8 and 9. 10 are connected in parallel.
The merging pipe 10 is connected to a pressure detection unit 11 and a pressure accumulation tank 12. Input circuit 1 for motors 3 and 4
Current detectors 15 and 16 are provided in 3 and 14, respectively.

As shown in FIG. 2, each of the flow rate detectors 6 and 7 is configured to send a stop signal when the discharge flow rate Q decreases to a predetermined stop flow rate Q ₀ . The pressure detector 11 is configured to send a start signal when the water pressure H in the merge pipe 10 has decreased to a predetermined start pressure H ₀ . The current detectors 15 and 16 are configured to transmit current signals corresponding to the operating currents I of the electric motors 3 and 4, respectively. The stop signal, start signal, and current signal are each guided to the control unit 17.

The control unit 17 includes start / stop control means for alternately operating the pumps 1 and 2, detection means for the pump operation continuation time T, detection means for the stop current I _{0 at} the time of input of the stop signal, and a coefficient K (for the spiral pump). In that case, K> 1, for example, K =
1.2) setting means, K * I calculation means, chattering pulse width t detection means by the flow rate detecting units 6 and 7, setting means for a pulse width limit value t ₀ corresponding to the operation continuation time T,
A means for determining the chattering pulse as the second stop signal when t> t ₀ and a means for storing the detected and calculated data while appropriately updating the data are provided.

Next, the operation of the above embodiment will be described. Normally, for example, when the pump 1 is started first in response to a start signal,
After that, the pump 1 responds to the stop signal or the stop current I _0.
Is stopped, and when a start signal is input next time, the pump 2 is started to perform the alternate operation. Pumps 1, 2
Is detected and stored each time the operation is started.

Now, the relationship between the flow rate Q (l / min) and the chattering pulse width t (sec) is known or clarified by a test run or the like. For example, when Q = 10, t = 1.5 Q = 20, t = 0.8, and Q = 30, t = 0.4.

In such a case, if the pulse width limit value t ₀ is set to, for example, 1.0 sec, the pulse width becomes t> 1.
Since the chattering pulse of 0 is determined as the second stop signal, the pump is stopped. However, the chattering pulse of t ≦ 1.0 is not determined as the second stop signal, and the pump continues to operate.

Similarly, if the pulse width limit value t ₀ is set smaller (for example, 0.5 sec), the flow rate range in which the chattering pulse is determined to be the second stop signal is further increased. Therefore, the pulse width limit value t ₀ can be selectively set in relation to the operation continuation time T, and the longer the T, the higher the probability of stopping by increasing the second stop flow rate.

Further, the upper limit of the flow rate operation stop is permitted with the boundary flow Q _f, Q> Q in order to prevent shutdown in large flow rate region is of _f, a pulse width corresponding to Q _f t _f
May be set as the limit value. That is, t ≦ t
_{Since the} chattering pulse _f (for example, 0.4 sec) is not determined to be the second stop signal, Q ≧ Q _f (30 l / mi)
The pump is not stopped by the chattering pulse in the flow rate range of n).

[0016] Alternatively, the driving current I _f that corresponds to Q _f calculated from I _f = K * I _0, for example I <t ₀ = 1sec in the region of I _f, t ₀ = a time of 2 sec in the region of I ≧ I _f It may be set as follows. That is, in the region of I < _If , the chattering pulse of t> 1 sec is determined as the second stop signal, but in the region of I ≧ _If , 1 <t <2 sec.
Even if there is a chattering pulse like this, the pump will not be stopped.

The present invention is not limited to the above embodiment, but is applicable, for example, even when the number of pumps is three or more. Further, the operation method may be a combination of the alternate operation and the parallel operation. In addition, various changes and applications are possible within the scope of the gist of the present invention.

[0018]

As described above, according to the present invention, the control of the automatic water supply device which can improve the reliability by averaging the pump operation time by positively utilizing the chattering pulse by the flow rate detecting section. A method can be provided.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a flow rate (Q) -water pressure (H) characteristic and a flow rate (Q) -operating current (I) characteristic of the embodiment.

[Explanation of symbols]

6, 7: flow rate detecting section, 11: pressure detecting section, 15, 16, ...
Current detector, H ₀ ... starting pressure, I ₀ ... stop current, Q ₀ ...
Stop flow rate, Q _f ... Boundary flow rate.

Claims (2)

(57) [Claims] 1. An automatic water supply apparatus comprising a flow detector for sending a stop signal in a region equal to or less than a stop flow, wherein a chattering pulse of the flow detector in a region exceeding the stop flow is selectively selected in relation to a pulse width. The control method of the automatic water supply device, wherein the second stop signal is set to the second stop signal. 2. When the pump operating current rises to a value equal to or higher than a current value calculated in relation to the stop flow rate,
2. The control method for an automatic water supply device according to claim 1, wherein the stop signal is cut off.