A drainage pump semi-water semi-air detection device, drainage pump and household appliance

Abstract

The application is suitable for the technical field of household electrical appliances, and provides a drainage pump semi-water semi-air detection device, a drainage pump and a household electrical appliance.The device comprises a current detection module, a control module and a power module;the current detection module is connected in series with a load loop of a motor;the current detection module comprises a sampling resistor and an operational amplifier;two ends of the sampling resistor are connected with input ends of the operational amplifier;output ends of the operational amplifier are connected with the control module;the control module and the current detection module are electrically connected with the power module.The application detects the water level state of the drainage pump through the current detection module, so that the motor can detect the semi-water semi-air state of the drainage pump, and the water pump can be stopped in time to avoid the motor discharging air in the semi-water semi-air state and causing noise.

Description

Technical Field

[0001] This application belongs to the field of home appliance technology, specifically relating to a half-water, half-gas detection device for a drain pump, a drain pump, and home appliances. Background Technology

[0002] Existing AC single-phase drainage pumps often experience a "half-water, half-air" phenomenon at the end of the drainage process due to reduced liquid volume and the introduction of air. This not only leads to unstable motor load and decreased operating efficiency but also generates significant noise, impacting user experience and environmental tranquility. Current technologies for detecting this half-water, half-air state have the following shortcomings: First, traditional sensor technology struggles to accurately determine the specific liquid content within the pump, hindering timely adjustments to motor operation. Second, existing detection methods lack sufficient sensitivity and reliability when dealing with complex water flow conditions, making them prone to misjudgments. Utility Model Content

[0003] This application provides a drainage pump half-water half-gas detection device, a drainage pump, and a household appliance. The detection device adopts a modular hardware structure design, which can achieve accurate detection of the drainage pump status without relying on complex algorithms.

[0004] To achieve the above objectives, this application provides a half-water, half-gas detection device for a drainage pump, which is connected to the motor driving the drainage pump. The device includes a current detection module, a control module, and a power supply module. The current detection module includes a sampling resistor and an operational amplifier. The sampling resistor is connected in series with the load circuit of the motor, and the two ends of the sampling resistor are connected to the input terminal of the operational amplifier. The output terminal of the operational amplifier is connected to the control module.

[0005] The control module and the current detection module are electrically connected to the power supply module, respectively.

[0006] This application uses a current detection module to monitor changes in the motor load current in real time. A sampling resistor converts the current signal into a voltage signal, which is then amplified by an operational amplifier and transmitted to the control module. This allows for accurate identification of current fluctuations in the drainage pump under semi-water, semi-gas conditions, providing data support for fault diagnosis. A power supply module provides a stable power supply to the system, ensuring reliable detection.

[0007] In one possible embodiment, the control module includes a microcontroller unit and a time-delay restart circuit. After receiving a stop command, the time-delay restart circuit starts a preset delay and sends a restart signal to the motor after the delay ends.

[0008] Specifically, the delayed restart circuit avoids damage caused by frequent motor starts and stops, automatically restarting after the preset delay, thus protecting the motor and improving the system's fault tolerance. The microcontroller unit enables intelligent control and optimizes the drainage pump's operating strategy.

[0009] In one possible embodiment, the current detection module further includes a filter circuit connected to both the sampling resistor and the input of the operational amplifier.

[0010] Based on the above embodiments, the filtering circuit can eliminate high-frequency noise in the current signal and improve sampling accuracy. This design is particularly suitable for industrial environments with electromagnetic interference, ensuring the accuracy of the detection data.

[0011] In one possible embodiment of the first aspect, a Hall sensor is further included. The Hall sensor is electrically connected to the control module and is fixedly installed outside the motor housing with its sensing end facing the motor rotor for real-time monitoring of the rotor speed signal.

[0012] Specifically, the Hall sensor monitors the rotor speed non-contactly, and combined with current data, it can provide a more comprehensive assessment of the pump's operating status. This application significantly reduces the false alarm rate through a dual-signal detection mechanism, making it suitable for more complex operating conditions.

[0013] Furthermore, it also includes a signal processing module electrically connected to the control module, comprising a comparator and a Schmitt trigger electrically connected in sequence, wherein the input of the comparator is connected to the output of the Hall sensor, and the output of the Schmitt trigger is electrically connected to the control module.

[0014] Furthermore, the Hall sensor can be a linear Hall sensor or a switch-type Hall sensor.

[0015] Based on the above embodiments, the comparator converts the Hall signal into a square wave, and the Schmitt trigger eliminates signal jitter through its hysteresis characteristic, generating a stable speed pulse. This effectively resists magnetic field interference, improves the reliability of speed detection, and thus can adapt to application scenarios with different accuracy requirements.

[0016] A second aspect of this application provides a drainage pump, including the detection device described in the first aspect, and further including an alarm module, which is electrically connected to a control module.

[0017] A third aspect of this application provides a household appliance that includes the drain pump described in the second aspect above.

[0018] The beneficial effects of this application are that, through the current detection module, the drainage pump can be identified in a timely manner when it is in a semi-water, semi-gas state; and through dual parameter monitoring of current and motor rotor speed, misjudgments caused by environmental interference (such as voltage fluctuations or short-term load changes) of a single parameter can be effectively eliminated. According to the state of the drainage pump, the motor operating state can be adjusted (such as stopping or reducing speed), thereby reducing vibration and noise caused by gas-liquid mixing and improving the user experience. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the circuit structure of a drainage pump half-water and half-gas detection device provided in an embodiment of this application;

[0021] Figure 2 This is a schematic diagram of a drainage pump half-water, half-gas detection device with a Hall switch provided in an embodiment of this application. Detailed Implementation

[0022] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0023] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0024] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0025] The following is combined Figure 1 and Figure 2 This application describes a drainage pump half-water, half-gas detection device provided in an embodiment.

[0026] like Figure 1 As shown, this embodiment provides a half-water, half-gas detection device for a drainage pump, including a current detection module, a control module, and a power supply module; wherein, the current detection module is connected in series with the load circuit of the motor, the current detection module includes a sampling resistor and an operational amplifier, the two ends of the sampling resistor are respectively connected to the input terminal of the operational amplifier, the output terminal of the operational amplifier is connected to the control module, and the control module and the current detection module are respectively electrically connected to the power supply module.

[0027] The current detection module is connected in series in the motor power supply circuit to monitor the motor operating current in real time. When the pump body is half water and half air, the motor load current will drop significantly (usually less than half of the current when the pump is full of water). The current detection module converts the current signal into a voltage signal, which is then amplified and transmitted to the control module.

[0028] Specifically, the current detection module is connected in series with a high-precision sampling resistor in the motor power supply circuit. When the motor is running, current flows through the sampling resistor, generating a voltage drop. This weak voltage drop signal is amplified by an operational amplifier to a voltage range that the control module can recognize. This design must consider the power tolerance of the resistor to avoid component damage caused by the large current at the moment of motor startup. In addition, the use of a differential amplifier circuit can effectively suppress common-mode interference and improve detection accuracy.

[0029] The current detection module also includes a filter circuit, which is connected in series at the input of the operational amplifier. It uses a combination of RC low-pass filtering (cutoff frequency 100Hz) and digital filtering (moving average algorithm) to effectively filter out high-frequency electromagnetic interference and signal glitches.

[0030] The control module is used to process information such as current and data in real time. It integrates a threshold comparator to determine whether the current meets preset conditions in real time.

[0031] The delay timer is used to control the motor restart delay time;

[0032] Output drive circuit: The motor start / stop and speed control commands are realized through optocoupler isolation control relays or MOSFETs.

[0033] The power supply module is used to supply power to the current detection module and the control module.

[0034] Further, see Figure 2 This device also includes a Hall sensor, which is installed near the motor shaft and measures the rotational speed by detecting the pulse signal generated by the rotating magnet. In a semi-water, semi-gas state, the motor speed fluctuates significantly due to the mixing of gas and liquid. After the Hall sensor detects the abnormal fluctuations, it generates a stable signal through a signal processing module (such as a comparator + Schmitt trigger) to assist the control module in making decisions.

[0035] The Hall sensor is either a linear Hall sensor or a switching Hall sensor, outputting a square wave signal whose frequency is proportional to the rotational speed. This signal is shaped by a Schmitt trigger before being input to the control module. During installation, ensure the distance between the sensor and the magnet is appropriate (typically 1-3mm) to avoid signal loss due to mechanical vibration. Adjustable mounting brackets can be designed for different types of motors (such as single-phase / three-phase asynchronous motors), using a snap-fit ​​structure to accommodate different shaft diameters and improve versatility.

[0036] The Hall sensor is electrically connected to the signal processing module, which in turn is electrically connected to the control module. The signal processing module includes a comparator and a Schmitt trigger, which are connected in sequence. The input of the comparator is connected to the output of the Hall sensor, and the output of the Schmitt trigger is electrically connected to the control module.

[0037] Specifically, after adding a Hall sensor, this device can avoid misjudgment based on the combined analysis of current and speed.

[0038] Set the current threshold based on the motor's rated current, and calculate the speed fluctuation frequency through spectrum analysis (such as FFT algorithm) to set the speed threshold.

[0039] When both the current fluctuation and the speed fluctuation frequency are greater than the speed threshold, the system is judged to be in a "half-water, half-gas" state, triggering the shutdown protection.

[0040] If only the current exceeds the limit, it may be caused by overload or short circuit, which will directly trigger an emergency shutdown.

[0041] If only the rotational speed is abnormal, it may be caused by mechanical jamming or sensor failure. The system will issue a warning and log the information.

[0042] Upon detecting a semi-water, semi-air state, the motor immediately stops and a countdown begins via a potentiometer-adjustable delay circuit. During the delay, the system continuously monitors the inlet water level (detected by a pressure sensor or float switch). If the water level rises to a safe level (e.g., exceeding the pump inlet by 50cm), the motor automatically restarts to avoid unnecessary shutdown. If the water level does not recover by the end of the delay, it is considered a "dry running risk," and a fault alarm signal is output.

[0043] Take the scenario of washing machine drainage as an example:

[0044] In the initial stage of drainage, the pump body is filled with water, the motor current is stable, and the Hall sensor detects a steady speed.

[0045] During the later stages of drainage, the water level drops, air enters the pump body, the current decreases significantly, and the speed fluctuation increases.

[0046] The current detection module detected that the current was below the threshold, and at the same time the Hall sensor signal showed that the speed fluctuation frequency was abnormal. The control module determined that the motor was in a half-water, half-air state and immediately stopped the motor.

[0047] The delayed restart circuit starts (e.g., 30 seconds). If the water level rises during this period, drainage will automatically restart. If the water level does not recover by the end of the delay, a fault alarm will be output to prevent abnormal noises caused by dry running or air venting.

[0048] A second aspect of this application provides a drainage pump, including the detection device described in the first aspect, and further including an alarm module, which is electrically connected to a control module.

[0049] A third aspect of this application provides a household appliance that includes the drain pump described in the second aspect above.

[0050] In the above embodiments, the drainage pump half-water and half-gas detection device, drainage pump and household appliance provided in this application, the detection device realizes accurate identification and intelligent control of the half-water and half-gas state of the drainage pump through modular hardware design and dual-parameter monitoring mechanism, solves the detection problem in the prior art, has both reliability and economy, is applicable to a wide range of household appliance scenarios, and has significant practical value.

[0051] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A device for detecting half-water and half-air in a drainage pump, connected to a motor driving the drainage pump, characterized in that, It includes a current detection module, a control module, and a power supply module; wherein, the current detection module includes a sampling resistor and an operational amplifier, the sampling resistor is connected in series with the load circuit of the motor, and the two ends of the sampling resistor are connected to the input terminal of the operational amplifier, and the output terminal of the operational amplifier is connected to the control module; The control module and the current detection module are respectively electrically connected to the power supply module.

2. The apparatus as claimed in claim 1, characterized in that, The control module includes a microcontroller unit and a time-delay restart circuit. After receiving a stop command, the time-delay restart circuit starts a preset delay and sends a restart signal to the motor after the delay ends.

3. The apparatus as described in claim 2, characterized in that, The current detection module also includes a filtering circuit, which is connected to the sampling resistor and the input terminal of the operational amplifier, respectively.

4. The apparatus according to any one of claims 1-3, characterized in that, It also includes a Hall sensor, which is electrically connected to the control module. The Hall sensor is fixedly installed outside the motor housing, with its sensing end facing the motor rotor, for real-time monitoring of the rotor speed signal.

5. The apparatus as described in claim 4, characterized in that, It also includes a signal processing module electrically connected to the control module. The signal processing module includes a comparator and a Schmitt trigger electrically connected in sequence. The input terminal of the comparator is connected to the output terminal of the Hall sensor, and the output terminal of the Schmitt trigger is electrically connected to the control module.

6. The apparatus as claimed in claim 5, characterized in that, The Hall sensor is either a linear Hall sensor or a switch-type Hall sensor.

7. A drainage pump, characterized in that, The detection device as described in any one of claims 1 to 6 further includes an alarm module, the alarm module being electrically connected to the control module.

8. A household appliance, characterized in that, Includes the drainage pump as described in claim 7.

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