JPS6014198B2 - automatic pump - Google Patents

Description

[Detailed Description of the Invention] In order to prevent the pressure switch that controls the operation of the pump from repeatedly turning ON and OFF in an automatic pump,
Effective amount of water in the pressure tank (pressure switch ON/OFF)
It is necessary to ensure a large amount of water (based on the difference between the water levels h, , and h2), which poses a problem in that the pressure tank becomes large.

The present invention provides an improved automatic pump capable of reducing the size of the pressure tank and preventing chattering of the pressure switch.

An embodiment of the present invention will be described below with reference to FIG. 1. Reference numeral 1 denotes an electric pump, which is equipped with a suction pipe 3 having a check valve 2 and a discharge pipe 5 leading to a faucet 4. Reference numeral 6 denotes a pressure tank having a pressure switch 7, inside which a piston 9 sealed with a ring 8 is slidably installed. It is connected to pipe 5.

Reference numerals 12 and 12' refer to a return passage in which the discharge side of the pump extends to the suction side; 13 indicates a leaf valve interposed in this return passage; a bellows 14 is always pressed against its valve seat by a spring 15; , 12' are closed.

Reference numeral 16 and 16' denote an inflow passage that connects the discharge pipe 5 to the pressure tank 6; 17 denotes a differential pressure valve interposed in this inflow passage; The stone chamber is connected to the inflow channel 16.
The diaphragm 18 is pressed against the valve seat by a spring 20 in the left chamber and closes the inflow passages 16, 16' leading to the pressure tank 6.

Next, to explain the operation of the automatic pump of the present invention, when the water faucet 4 is used with a relatively high pressure, the pressure in the discharge pipe 5 is lower than the set pressure of the relief valve 13. is not opened and the reflux paths 12, 12' are blocked.

Therefore, the pressure P2 in the discharge side recirculation path 12 is the same as the pressure P in the discharge pipe 5 (P, = P2), and the diaphragm 18 of the differential pressure valve 17 is pressed against the valve seat by the spring 20, and the pressure tank 6 Since the inlet channels 16, 16' are blocked, the pump is in continuous operation. When the faucet 4 is further tightened from this state, the discharge pressure increases, so the bellows 14 of the relief valve 13 rises against the spring 15, and a gap is created between the valve seat and the valve seat, so that some of the discharged water is circulated back to the suction side through the open reflux channels 12, 12'.

The pressure P2 in the discharge side recirculation passage 12 decreases based on the resistance caused by this circulating flow, but when the pressure difference between P and P2 is less than the set pressure of the differential pressure valve 17, the inflow passages 16 and 16' remain closed. However, the pump 1 continues to operate in the same manner as above.
When the faucet 4 is completely closed, the opening degree of the IJ leaf valve 13 further increases, and the amount of water in the return channels 12, 12' further increases, and due to the increase in channel resistance, a pressure difference of P, - F2 is generated in the differential pressure valve 17.
The pressure becomes lower than the set pressure, and the pressure P of the discharge pipe forces the diaphragm 18 to the left against the spring 20.
The lid pressure valve 17 opens.

The pump discharge water is thus sent to the pressure tank 6 through the inflow passages 16, 16', pushes up the piston 9 to compress the air, and stops the operation of the pump at the OFF setting pressure of the pressure switch 7. Also, when the faucet 4 is opened, the discharge pipe 5 and the pressure tank 6 are
The check valve 10 suddenly opens due to the pressure difference, and the pressure switch 7 is turned on due to the decrease in the internal pressure of the pressure tank 6, and the pump starts operating again.

Generally, in an automatic pump, when the water faucet is used at a pressure higher than the OFF setting pressure of the pressure switch, the pressure switch repeatedly turns ON and OFF as shown in FIG. 3, causing the pump to operate intermittently.

This adversely affects the life of the pressure switch and motor, and the amount of water discharged fluctuates, causing the water temperature in showers, water heaters, etc. to change. On the other hand, even when the automatic pump of the present invention is used with the faucet turned off, it can be operated continuously as shown in Figure 2 by the action of the return valve and the differential pressure valve in the inflow path as described above. This improves the reliability of the motor pressure switch, eliminates pulsation in the amount of water, and makes it possible to downsize the pressure tank.

In particular, in the present invention, the reed pressure valve that intervenes in the flow of water into the pressure tank is structured so that when the relief valve opens and the amount of returned water exceeds a predetermined value, the pressure drop due to the water flow resistance is detected and the valve is opened. , its sensitivity is extremely good,
Moreover, it has great practical value as an automatic pump equipped with a small pressure tank, as there is no need to use any resistance valve in the discharge pipe, and losses can be reduced accordingly.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an automatic pump device according to the present invention.
3 and 3 are characteristic diagrams showing the operating conditions of the pump of the present invention and the conventional automatic pump, respectively. 4... Water faucet, 5... Pump discharge pipe, 6
......Pressure tank, 7...Pressure switch, 10...Check valve, 11...0 outflow pipe,
12, 12'...reflux path, 13...relief valve! 6, 16'... Inflow path, 17...
...Differential pressure valve. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 A pressure tank connected to the pump discharge pipe leading to the faucet via an outflow pipe with a check valve, and a reflux path that communicates the discharge side of the pump with the suction side, and is opened at a discharge pressure of a predetermined value or higher. An automatic pump comprising a relief valve and a differential pressure valve that is interposed in an inflow path that communicates the discharge pipe with a pressure tank and opens when the flow rate in the recirculation path exceeds a predetermined value.