JPH048320Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an automatic water supply device, and more particularly to an automatic water supply device that variably controls the number of operating pump units connected in parallel.

[Technical background of the invention and its problems]

In conventional automatic water supply systems that variably control the number of operating pump units in response to increases and decreases in the amount of water demanded, it is necessary to provide the same number of pressure switches as pump units and to set their operating points to be different from each other. As a result, the number of pressure switches and their attached parts increases, which not only requires more effort to equip, but also requires more effort and skill to adjust each pressure switch.

In order to solve these problems, a pump has been proposed that is equipped with a lower limit pressure contact, an upper limit pressure contact, and a timer circuit that works with these two contacts to start and stop the pump section in sequence. (Japanese Patent Publication No. 51-21201). In this device, as mentioned above, in order to stop the pump section, an upper limit pressure contact is provided that operates at the stop pressure _point. ) must be set significantly lower than the pump cut-off pressure _H3 . As a result, as can be seen from Figure 1, independent operation (N = 1)
The switching operation range (O to Q ₁ ) at the time becomes wider,
Since the switching range (Q ₂ to _{Q 3} ) between individual operation and parallel operation (N = 2) becomes narrower, the frequency of intermittent and switching increases, and the accompanying pressure fluctuations also increase. There is a problem. The pump startup control described in the above publication is as follows:
When the starting pressure switch is turned on, only the first pump is started, and at the same time a timer is activated to prevent the later pumps from starting and keep them on standby. However, once the starting pressure switch is turned on, the starting pressure switch is turned off. When the starting pressure switch is turned on again, the timer is turned off, that is, the timer is reset, and when the starting pressure switch is turned on again, the timer is activated to wait several seconds for starting the subsequent pump. In other words,
At the start of parallel operation, the subsequent pump does not start instantaneously, but starts after a predetermined time set by a timer. For this reason, for example, when the pressure in the merging pipe decreases due to an increase in the amount of water demand, and when it is desired to start the succeeding pump and switch to parallel operation, there is a problem that the starting of the succeeding pump is delayed and the pressure decreases. However, due to the delay in starting up the later pumps, there is a concern that, for example, when supplying water to a building, water may be cut off on the top floor.
In addition, in automatic water supply equipment, it is desirable that pressure fluctuations at the terminal end be small, and for this purpose, a constant pressure valve, drive control means for the pump section, etc. may be provided, or a pump with constant pressure characteristics may be used. In such cases, or during parallel operation where pressure fluctuations due to flow rate fluctuations are relatively small,
It is difficult to reliably stop the pump section at the above upper limit pressure.

[Purpose of invention]

The present invention was made to solve the above-mentioned problems, and its purpose is to make equipment and adjustment simple and easy, and to reduce the accuracy of intermittent and switching operations, etc. Another object of the present invention is to provide an automatic water supply device that can perform reliable automatic operation even when pressure fluctuations due to flow rate fluctuations are small.

[Summary of the idea]

The present invention includes a pressure detection section that sends out a starting signal to start the pump sections each time the internal pressure of a confluence pipe in which a plurality of pump sections are connected in parallel drops to a certain lower limit value; a delay means that blocks the later start signal until a predetermined time period has elapsed after the input of the sent earlier start signal, and instantaneously starts the later pump section with the next start signal after the predetermined time period has elapsed; The present invention is characterized by comprising a flow rate detection unit that sends out a stop signal for sequentially stopping the pump unit each time the flow rate in the confluence pipe decreases to a plurality of different predetermined lower limit values.

[Effect of idea]

As described above, the present invention includes a pressure detection section that sends out a starting signal every time the pressure in the confluence pipe drops to a certain lower limit value, and a predetermined period of time after the advance starting signal sent from this pressure detection section is input. Since the pump is equipped with a delay means that shuts off the later start signal until the time period has elapsed, multiple pump sections can be started in sequence using a single pressure detection section, and the frequency of interruptions and switching of operations can be reduced. can.

Moreover, this delay means is designed to instantaneously start the later pump unit when the next start signal is issued after a predetermined time has elapsed since the earlier start signal was input. is activated quickly, and a drop in pressure within the confluence pipe can be prevented.

In addition, it is equipped with a flow rate detection unit that sends out a stop signal to stop each of the pump units each time the flow rate in the confluence pipe drops below a plurality of different predetermined lower limit values, so pressure fluctuations due to flow rate fluctuations are small. It is possible to reliably stop the vehicle even in the event of an emergency, and highly accurate automatic operation can be performed.

[Example of idea]

In FIG. 2, the two pump parts 1 and 2 are
Each suction side is led to a water tank 4 via a foot valve 3, and the discharge side is connected in parallel to a confluence pipe 7 via a check valve 5 and a gate valve 6. The confluence pipe 7 is provided with a flow rate detection section 8 and a pressure detection section 9, and a pressure tank 10 and a water supply pipe 11 are connected to its downstream end. A water faucet 12 and other desired equipment (not shown) are connected to the water supply pipe 11 . The flow rate detection unit 8 detects the flow rate Q in the confluence pipe 7 (see Fig. 4).
A first switching element 8a (see Fig. 3) sends out a stop signal to stop the independent operation of one pump section each time Q1 decreases to the first lower limit value _Q1 , and a first switching element 8a (see Fig. 3)
and a second opening/closing element 8b that sends out a stop signal to stop the other pump section for canceling the parallel operation each time Q2 decreases to the second lower limit value _Q2 .
The pressure detection unit 9 detects the pressure H (fourth
The pump includes an opening/closing element 9a that sends out a starting signal to start the pump section every time the voltage (see figure) falls to a certain lower limit value _H1 . Further, each output signal of the flow rate detection section 8 and the pressure detection section 9 is led to a control section 13, and the drive motors _M1 and _M2 of the pump sections 1 and 2 are controlled to start and stop.

FIG. 3 shows an example of a control circuit that includes the switching elements 8a, 8b, 9a, the control section 13, etc., and controls the starting and stopping of the electric motors _M1 and _M2 . In the same figure, electromagnetic switches MC ₁ and MC ₂ are connected to the respective first
By opening and closing switching elements MC _1a and MC _2a , motors M ₁ and M ₂ are controlled to start and stop, and
The first relay X ₁ is energized by closing at least one of the second switching elements MC _1b and MC _2b . Alternating relay MR is
When the first relay _X1 is in a de-energized state, its first switching element _X1a is closed to be energized, thereby switching the changeover switch MRa. Therefore, electric motors M ₁ and M ₂
are alternately enabled to start each time both inputs are cut off. Also, the _second relay of the first relay
The switching element X _1b is closed each time one of the electric motors M ₁ and M ₂ is started, and starts the timer TR. The timer TR has a first switching element TRa that is closed until a first predetermined time period has elapsed after being activated, and a second switching element TRa that is closed when a second predetermined time period has elapsed after being activated.
It is equipped with a switching element TRb. Then, while TRa is closed, the switching element X _3a of the third relay X ₃
is kept closed.

The switching element 9a of the pressure detection section ₉ is connected in parallel with the switching element It remains closed. Therefore, after startup, H≧H ₂ and 9a is opened, but in the case of Q≦Q ₁ , even if 8a is not closed and remains open, MC ₁ (or MC ₂ ) remains in the excited state. is maintained so that frequent starting and stopping of electric motor M ₁ (or M ₂ ) does not occur. Furthermore, the switching element 9a is connected in series with the second switching element TRb of the timer TR and the fourth relay _X4 , so that while TRb is open, the _fourth relay Since X _4a is not closed during that time, the parallel operation command signal for motors M ₁ and M ₂ is not transmitted until the second predetermined time elapses, that is, the stopped motor The starting signal for is cut off.

The first switching element 8a of the flow rate detection section 8 is connected in series with the second relay _X2 , so that when 8a is opened (that is, when Q≦Q ₁ ), _the switching _element It's getting old. X _2a is connected in parallel with the above TR _a , and if they are both opened, since 9a is already open after startup, MC _1a (or MC _2a ) is opened, and motor M ₁ (or M ₂ ) is now being stopped. Also,
The second switching element 8b is connected in series with the second switching element X _4b of the fourth relay X ₄ and in parallel with 9a, and when 8b is opened (that is, when Q≦Q ₂ )
Since 9a is open after the parallel transition, when X _4a is opened, motor M ₂ (or M ₁ ) is stopped and shifted to independent operation, and X _4b is also opened, so Q≧Q ₂ again and 8b Even if 9a is closed, H≦H ₁ and X ₄ will not be in an excited state unless 9a is closed, so the problem of chattering will not occur.

Now, the pressure tank 10 has accumulated enough pressure and H=
If the faucet 12 is opened when the water tap 12 is stopped in the state of H ₃ (see FIG. 4), the water in the pressure tank 10 flows out and the pressure in the confluence pipe 7 decreases. Then, when the pressure decreases to the constant lower limit value _H1 , the opening/closing element 9a of the pressure detecting section 9 is closed and a starting signal is sent, so that either one of the electric motors selected by the alternating relay MR, For example, M ₁ is activated. At the same time, the _first relay
X _3a is closed until a predetermined period of time elapses. Therefore, after startup, H≧H ₂ and 9a
However, if Q≦Q ₁ , even if 8a is not closed and X _2a remains open, the motor M ₁ will not be stopped. Also, if Q>Q ₁ , 8a
Even if TRa is opened after the first predetermined time has elapsed due to X _2a being closed and X 2a being closed, operation continues in the same manner as described above. On the other hand, since TRb remains open until the second predetermined time period elapses after 9a is closed, the starting signal is cut off.
When 9a is closed again after the second predetermined time has elapsed, _{the fourth} relay motor _M2 is started and enters parallel operation. In this state, since Q≧Q ₂ , 8b is already closed, so even if H>H ₂ and 9a is opened, the parallel operation state is maintained.

When the flow rate decreases to the second lower limit value _Q2 ,
By opening 8b, X _4a is opened, the parallel operation is canceled, and only one electric motor M ₁ is operated independently. In this state, X _4b is also open, so even if Q≧Q ₂ again and 8b is closed, H≦H ₁ and unless 9a is closed, parallel operation will occur. There is no problem such as chattering. and,
By closing the faucet 12, the flow rate Q in the confluence pipe 7 decreases to the first lower limit value _Q1 , and when 8a is opened, X _2a is opened (TRa was opened before that), so that X _3a Since 9a is already opened, the pressure of H ₃ is accumulated in the pressure tank 10 and the electric motor M ₁ is stopped. At this time, by closing X _1a , MRa is switched to the MC ₂ side,
During the next operation, the other electric motor _M2 will be started first.

According to the above configuration, the pressure detecting section 9 sends out a starting signal every time the pressure H in the merging pipe 7 decreases to a certain lower limit value _H1 , and the advance starting signal from this pressure detecting section 9 is inputted. a timer that can cut off the late start signal until the second predetermined time has elapsed;
Since the delay means including the TR is provided, the plurality of pump sections 1 and 2 can be sequentially started using the single pressure detection section 9. Therefore, the installation and adjustment of the pressure detection section 9 are simple and easy. Moreover, the delay means including the timer is configured to instantaneously start the rear pump 2 when the next start signal is issued after a predetermined time has elapsed since the first start signal was input. The subsequent pump 2 can be started quickly, and a drop in pressure within the confluence pipe can be prevented. Therefore, when the water demand increases and the discharge amount of the first pump 1 cannot cover it and shifts to parallel operation, the pressure detection unit 9
When the pump issues a start signal, the subsequent pump 2 starts instantly, which eliminates the pressure drop and prevents a drop in water pressure when transitioning to parallel operation.When supplying water to a building, etc., the water supply can be cut off on the top floor. It is possible to solve problems such as In addition, the confluence pipe 7
Equipped with a flow rate detection section 8 that sends a stop signal every time the flow rate within the flow rate drops to different predetermined lower limit values _Q1 to _Q2 , reliable automatic operation is possible even when pressure fluctuations due to flow rate fluctuations are small. In addition, the intermittent operation range Q to Q ₁ during individual operation can be made sufficiently narrow, and the switching range Q ₂ to _{Q 3} between individual operation and parallel operation can be made wide, so that the operation can be It is possible to sufficiently reduce the frequency of occurrence of interruptions, switching, etc.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can also be applied, for example, to a case where the number of pump parts is three or more. In addition, various modifications or wide applications are possible within the scope of the gist of the present invention.

[Brief explanation of drawings]

Fig. 1 is a diagram for explaining the operating characteristics of the conventional example, Fig. 2 is a system diagram showing an embodiment of the present invention, Fig. 3 is an electric circuit diagram of the same example, and Fig. 4 is a diagram of the same example. FIG. 3 is a diagram for explaining operating characteristics. DESCRIPTION OF SYMBOLS 1, 2... Pump part, 7... Merging pipe, 8... Flow rate detection part, 8a, 8b, 9a... Switching element, 9...
...Pressure detection section, 13...Control section, MC ₁ , MC ₂ ...
...Electromagnetic switch, TR...Timer, X ₁ , X ₂ , X ₃ ,
X ₄ ...Relay.

Claims (1)

[Claim for Utility Model Registration] In an automatic water supply device having a plurality of pump sections whose discharge side is connected in parallel to a merging pipe, the pump section is started each time the pressure in the merging pipe drops to a certain lower limit value. a pressure detection part that sends out a starting signal to start the engine; a pressure detection part that cuts off the later starting signal until a predetermined period of time has elapsed after the first starting signal sent from the pressure detection part is input; a delay means for instantaneously starting the subsequent pump section in response to the next start signal; and a stop signal for stopping each of the pump sections each time the flow rate in the merging pipe drops below a plurality of different predetermined lower limit values. An automatic water supply device characterized by comprising a flow rate detection section.