CN103089660A - Water pump with water shortage protection device - Google Patents

Abstract

The invention relates to a water pump with a water shortage protection device, which comprises a motor, a pump body and the water shortage protection device, wherein the motor adopts a direct current brushless motor, the direct current brushless motor comprises a stator component, a permanent magnet rotor component and a controller, the controller comprises a direct current power supply, an inverter unit, a microprocessor, a pulse width modulation driving circuit and a rotor position detection unit, the water shortage protection device comprises a rotor position detection unit, a microprocessor and an execution module arranged in the microprocessor, the rotor position detection unit picks up the actual rotating speed (V1) of the rotor component and transmits the actual rotating speed to the microprocessor, the execution module in the microprocessor judges whether the actual rotating speed (V1) is greater than a set rotating speed Value (VB), if the actual rotating speed (V1) is greater than the set rotating speed Value (VB), the execution module in the microprocessor outputs a signal to control the inverter unit to cut off, the water pump is stopped. The device is simple and easy to install, small in size, relatively power-saving and cost-saving.

Description

A water pump with a water shortage protection device

technical field

The invention relates to a water pump with a water shortage protection device.

Background technique

At present, the aquarium water pumps on the market have a lot of wear and tear on the pump body when they are idling away from the water. In view of this situation, the traditional water pumps use no-load protection devices. Some of the no-load protection devices use float switches. The up and down of the floating ball drives the up and down of the float to make the switch on and off. This structure is relatively complicated and bulky, and it is usually used in water pumps driven by AC motors; some no-load protection devices use electronic switches to generate water level signals through water level sensors. The signal is sent to the controller, and the controller then controls the relay to disconnect the power supply. Most aquarium water pumps are driven by AC motors, and the no-load protection device is separated from the AC motor independently. Therefore, installation is troublesome, the structure is complicated, and it consumes more power. High cost of use.

Contents of the invention

The invention provides a water pump with a water shortage protection device, which uses a DC brushless motor as a power source, uses the original hardware in the motor controller to match and form a built-in water shortage protection device, and does not need an independent external water shortage protection device device, easy to install, small in size, more energy-saving and cost-saving.

Technical scheme of the present invention is realized like this:

A water pump with a water shortage protection device, including a motor, a pump body and a water shortage protection device. The cavity inside the pump body is equipped with an impeller, the pump body is provided with a water inlet and a water outlet, and the rotating shaft on the motor extends into the cavity. The inside is connected with the impeller, and the motor adopts a DC brushless motor. The DC brushless motor includes a stator assembly, a permanent magnet rotor assembly and a controller. The controller includes a DC power supply, an inverter unit, a microprocessor, and a pulse width modulation drive. Circuit and rotor position detection unit, the water shortage protection device includes a rotor position detection unit, a microprocessor and an execution module installed in the microprocessor, the rotor position detection unit picks up the actual speed V1 of the rotor assembly and sends it to the microprocessor The execution module in the microprocessor judges whether the actual speed V1 is greater than the set speed value VB. If the actual speed V1 is greater than the set speed value VB, it indicates that the water pump is in a state of water shortage. The execution module in the microprocessor outputs a signal to control the inverter. The variable unit cuts off the power supply of the winding on the stator assembly, so that the water pump stops running.

The executive module in the above-mentioned microprocessor compares the actual speed V1 with the set speed value VB at intervals of a time period T. If the actual speed V1 is greater than the set speed value VB for several times, the water pump will stop running. The time period T is not more than 1 hour.

The above-mentioned microprocessor is a single-chip microcomputer or a digital signal processor, and the rotor position detection unit includes a Hall element Hall and A/D conversion.

Compared with the prior art, the technical solution of the present invention has the following advantages: a DC brushless motor is used as a power source, and the original hardware in the motor controller is used for matching to form a built-in water shortage protection device. The water shortage protection device includes the position of the rotor The detection unit, the microprocessor and the execution module installed in the microprocessor. The rotor position detection unit picks up the actual speed V1 of the rotor assembly and sends it to the microprocessor. The execution module in the microprocessor judges whether the actual speed V1 is greater than the set value. The speed value VB, if the actual speed V1 is greater than the set speed value VB, it indicates that the water pump is in a state of water shortage, and the output signal of the execution module in the microprocessor controls the inverter unit to cut off the power supply of the winding on the stator assembly, so that the water pump stops running. It does not need an independent external water shortage protection device, easy to install, small in size, relatively power-saving, and cost-saving; the execution module in the microprocessor performs a comparison between the actual speed V1 and the set speed value VB at intervals T , if the actual rotational speed V1 is greater than the set rotational speed value VB for several times, the water pump is stopped to stop the water pump, so that the detection of the water pump operation is more accurate.

Description of drawings

Fig. 1 is the structural representation of water pump of the present invention;

Fig. 2 is the schematic diagram of the principle of the three-phase motor controller of the water pump of the present invention;

Fig. 3 is the schematic diagram of the principle of the one-phase motor controller of the water pump of the present invention;

Fig. 4 is a schematic diagram of the speed change of the water pump motor of the present invention after leaving the water;

Fig. 5 is a flow chart of water pump control in the present invention;

FIG. 6 is a flow chart of the improved water pump control of FIG. 5 .

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing.

As shown in Figure 1, Figure 2 and Figure 3, the water pump of the present invention includes a motor 2, a pump body 1 and a water shortage protection device. The water inlet 11 and the water outlet 12, the rotating shaft on the motor 2 extends into the cavity and connects with the impeller, the motor 2 adopts a DC brushless motor, and the DC brushless motor includes a stator assembly, a permanent magnet rotor assembly and a controller 21. The controller 21 includes a DC power supply, an inverter unit, a microprocessor, a pulse width modulation drive circuit, and a rotor position detection unit. The rotor position detection unit includes Hall elements and A/D conversion. The microprocessor is a single-chip microcomputer or A digital signal processor, a current detection unit detects the current of the winding, which includes a resistor R connected in series with the winding and A/D conversion.

As shown in Figure 4, when the water pump is out of water, the speed of its rotor assembly increases, and the actual speed of the rotor assembly increases to a constant value. The water shortage protection device includes a rotor position detection unit, a microprocessor and a The execution module in the microprocessor, the rotor position detection unit picks up the actual speed V1 of the rotor assembly and sends it to the microprocessor, the execution module in the microprocessor judges whether the actual speed V1 is greater than the set speed value VB, if the actual speed V1 is greater than The set speed value VB indicates that the water pump is in a state of water shortage. The output signal of the execution module in the microprocessor controls the inverter unit to cut off the power supply of the winding on the stator assembly, so that the water pump stops running. When the water pump leaves the water, the actual speed of the motor V1 starts to rise until it reaches a certain value, so the speed value VB can be set. When the actual speed V1 is greater than the set speed value VB, it is considered that the water pump is out of water, and the output signal of the execution module in the microprocessor controls the inverter unit to cut off The supply of power to the windings on the stator assembly stops the pump.

As shown in Figure 5, the operation process of the water pump is as follows: power-on reset, the brushless DC motor controller initializes the system, can initialize the set detection times N=0, and drive the water pump to run, when the rotor position detection unit picks up the actual speed of the rotor assembly V1 is sent to the microprocessor. The execution module in the microprocessor judges whether the actual speed V1 is greater than the set speed value VB. If the actual speed V1 is greater than the set speed value VB, the execution module in the microprocessor outputs a signal to control the inverter. The unit cuts power to the windings on the stator assembly, stopping the pump.

As shown in Figure 6, when the water pump is running, the execution module in the microprocessor compares the actual speed V1 with the set speed value VB every other time period T. The number of times is recorded in N, and the value of N Add 1, if the actual speed V1 is greater than the set speed value VB for several times, the water pump will stop running. For example, the number of times N0 can be set to 5 times, and the time for judging is equivalent to 5T. Within the time period of 5T, several The second actual speed V1 is compared with the set speed value VB, which will make the judgment more accurate. Said time period T is not more than 1 hour.

Claims (4)

1. A water pump with a water shortage protection device, including a motor, a pump body and a water shortage protection device. The cavity inside the pump body is equipped with an impeller, and the pump body is provided with a water inlet and a water outlet. The rotating shaft on the motor extends into the The inside of the cavity is connected with the impeller, and the motor adopts a DC brushless motor. The DC brushless motor includes a stator assembly, a permanent magnet rotor assembly and a controller. The controller includes a DC power supply, an inverter unit, a microprocessor, a pulse width The modulation drive circuit and the rotor position detection unit are characterized in that: the water shortage protection device includes a rotor position detection unit, a microprocessor and an execution module installed in the microprocessor, and the rotor position detection unit picks up the actual rotational speed of the rotor assembly (V1) and sent to the microprocessor, the execution module inside the microprocessor judges whether the actual speed (V1) is greater than the set speed value (VB), if the actual speed (V1) is greater than the set speed value (VB), it indicates that the water pump In the state of water shortage, the output signal of the execution module in the microprocessor controls the inverter unit to cut off the power supply of the winding on the stator assembly, so that the water pump stops running. 2. A water pump with a water shortage protection device according to claim 1, characterized in that: the execution module in the microprocessor carries out the actual rotational speed (V1) and the set setting at intervals of a time period (T). Comparing the fixed speed value (VB), if the actual speed (V1) is greater than the set speed value (VB) for several times, the water pump will stop running. 3. A water pump with a water shortage protection device according to claim 2, characterized in that: a time period (T) does not exceed 1 hour. 4. A water pump with a water shortage protection device according to claim 2 or 3, characterized in that: the microprocessor is a single-chip microcomputer or a digital signal processor, and the rotor position detection unit includes a Hall element (Hall) and a A/D conversion.

Images