JPS62288385A - Electric pump - Google Patents

Abstract

PURPOSE:To prevent a water hammer by connecting a pressure switch, a flow rate switch, and a timer which is turned off when a defined period time passed after said flow rate switch is turned off in parallel and connecting them to a motor in series. CONSTITUTION:A pressure switch device 5, the switch 9a of a flow rate switch device 9, and the switch 10a of a timer 10 are connected in parallel, while being connected in series to a part in between the motor of a pump 3 and a power source. Thereby, the operation of the pump 3 is continued even after the contact 9a of the flow rate switch 9 is turned off due to the timer 10, and a stored pressure is not transmitted to a check valve 2 without causing a water hammer when the pump is stopped.

Description

[Detailed description of the invention] 3. Detailed description of the invention Industrial applications TECHNICAL FIELD The present invention relates to a self-operating pump.

BACKGROUND OF THE INVENTION A conventional electric pump will be explained below based on FIG. 4. In general, automatic pumps, as shown in FIG. Water is sucked in through the check valve 2 and sent to the discharge pipe 7.In order to automatically operate the pump in the pipeline on the discharge side from the impeller 3, it is turned on when the pressure in the pipeline decreases. A pressure switch 5 that starts the motor, a flow rate switch 4 that turns on when the flow rate in the pipeline exceeds a certain value, and turns off and stops the motor when the flow rate falls below a certain value, and a pressure that accumulates the pressure in the pipeline. It has a tank 6. When a user opens and closes a faucet 8, the pump is automatically turned on and off due to changes in the pressure in the pipe on the discharge side of the pump and increases and decreases in flow rate.

Conventionally, in this type of pump, the flow rate switch is designed to turn off when the flow rate falls below 1 to 3 e/min.

Problems to be Solved by the Invention The check valve 2 is provided to prevent water in the pump from flowing back toward the suction pipe 1 when the pump is stopped.

When the check valve 2 closes, the high pressure inside the pressure tank 6 is applied to the check valve 2 because the pump 3 is stopped, and the check valve 2 closes.
closes vigorously.

At that time, a water hammer phenomenon occurred, causing impact noise and vibrations in the piping, causing problems.

Means for Solving the Problems In order to solve the above problems, the present invention starts the motor when either the pressure switch or the flow rate switch is turned on, and starts the motor for a certain period of time after the flow rate switch is turned off. If you later turn it off, the timer will stop when it turns off.

Function: With the above configuration, even if the flow of water in the pipe line decreases, the motor continues to operate for a certain period of time, so the pressure inside the pump does not drop suddenly and the check valve does not close suddenly.

Embodiments Below, embodiments of the electric pump of the present invention are shown in FIGS. 1 to 4.
A detailed explanation will be given along the diagrams.

3 to 3 and 5 to 8 are the same as those of the conventional electric pump shown in FIG. 5, so a detailed explanation will be omitted.

Reference numeral 9 denotes a flow rate switch device, which has a switch 9a that is turned on when the amount of water passing through is above a certain amount and turned off when it is below a certain amount, and a switch 9b that operates in the opposite manner.

10 is a timer connected to the switch 9b, and when the switch 9b is turned on, the timer is set for a certain period of time, for example, from 1 to 10.
A switch 10a is provided which is kept on for a second.

The pressure switch device 5, the switch 9a of the flow rate switch device 9, and the switch 10a of the timer 10 are connected in parallel, and are connected in series between the motor of the pump 3 and the power source.

A time chart of the operation of the electric pump of the present invention is shown in FIG. As shown in FIG. 3, when the faucet 8 is opened, the pressure inside the pressure tank 6 and the pipe 7 decreases, and the pressure switch 5 is turned on, at the same time the motor of the pump 3 is activated. As a result, water begins to flow through the pump 3 and the contact 9a of the flow rate switch device 9 is turned on. When the pressure inside the pump 3 increases due to activation of the motor, and the pressure rises above the operating setting pressure of the pressure switch 5, the pressure switch 5 is turned off. However, since the contact 9a of the flow rate switch device 9 remains on, the motor M continues to operate. When the flow rate falls below a certain value by closing the faucet 8, the contact 9a of the flow rate switch 9 is turned off and the contact 9b is turned on. Then, the timer 10 is activated, the timer switch 10a is turned on for 1 to 10 seconds, and the motor continues to operate, and then the timer switch 10a is turned off and the motor is stopped. Generally, during pump operation, the check valve 2 opens as shown in Figure 4 (with an opening degree that corresponds to the flow rate. The larger the flow rate, the larger the opening degree becomes.The faucet 8 is fully opened and the pump is operated at a large flow rate. If the faucet is suddenly closed while the faucet is running, the pump 3 will stop as described above.Faucet 8
When the check valve 2 is fully open, the opening degree is large, but in the electric pump of the present invention, even after the contact 9a of the flow rate switch 9 is turned off, the pump continues to operate by the timer 10 for 1 to 10 seconds. I am made to do so. At this time, the pressure stored in the pressure tank 6 is not transmitted to the check valve 2 because the pump 3 is operating. Moreover, since there is no water flow passing through the pump 3 at this time, the check valve 2 quietly closes from the state shown in FIG. 4C to the state shown in FIG. 4A.

After the pump 3 stops operating, the pressure in the pressure tank 6 is transmitted to the check valve 2, but the check valve 2 is already closed, so
Water hammer does not occur. Since the check valve 2 can be sufficiently closed within 1 to 10 seconds after the flow rate switch 4 is turned off, the setting time of the timer 10 may be 1 to 10 seconds.

Effects of the Invention As described above, the present invention has a pressure switch, a flow rate switch, and a timer that turns off after a predetermined time after the flow rate switch is turned off, which are connected in parallel and connected in series with the motor. The pressure on the discharge side of the pump does not return to the check valve immediately after the faucet is closed, and even though the check valve is closed, the pressure on the discharge side is applied to the check valve, causing a water hammer phenomenon. A large impact does not produce any sound.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a stop valve of an embodiment of the electric pump of the present invention, and FIG. 5 is a block diagram of a conventional example. 1... Suction port 2... Check valve 3...
・Pump 5...Pressure switch 6...
Pressure tank 7...Discharge pipe 8...Faucet
9...Flow rate switch device 10...Timer Name of agent Patent attorney Toshio Nakao and 1 other person 1-11 Sales 524. Blind? ---Daughter f child total--rlo, Fu.

Claims (1)

[Claims] A pressure switch provided on the discharge side of the pump and turned off when the pressure on the discharge side of the pump exceeds a predetermined value; and a pressure switch provided on the discharge side of the pump that turns off when the pressure on the discharge side of the pump becomes less than a predetermined value. A flow rate switch that turns off at a certain time and a timer that keeps it on for a predetermined period of time after the flow rate switch is turned off are connected in parallel, and this parallel connection body is inserted between the motor of the pump and the power source. electric pump.