Device and method for preventing empty pumping

Abstract

The invention discloses an empty pumping prevention device which comprises a water tank, a water pump, a heater, a temperature sensor and a controller. A water outlet is formed in the bottom of the water tank; the temperature sensor is close to the water outlet; the controller is connected with the temperature sensor, the water pump and the heater and used for controlling the heater to heat; after the heater stops heating, the water pump is controlled to work, and water pumping action is executed; when the water pump works, the temperature data collected by the temperature sensor are continuously read, and the current temperature drop slope is calculated; then performing water-free judgment according to the numerical value of the current temperature drop slope; and when no water exists in the water tank, the water pump stops working. According to the empty pumping prevention device, no-water judgment can be achieved under the conditions that the product structure is not changed and sensors such as a flowmeter and a Hall sensor are not added, so that the water pump is controlled to stop working in time, and the problem that the user experience is poor due to empty pumping noise is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid heating, and in particular to an anti-air pumping device and method. Background Art

[0002] The bottom of the coffee machine water tank is equipped with a heating plate, an NTC temperature sensor and a water outlet. When the coffee machine is working, it stops heating the water after heating it to the preset temperature and starts pumping water to extract coffee. When the water tank is heated to the preset temperature, the amount of water in the water tank is calculated, and the pumping time of the water pump is set according to the calculated amount of water. Due to the influence of the ambient temperature and the difference in the heating plate, the water amount is not accurately judged, so the water in the water tank has been pumped out, and the water pump is still working, which will generate noise and cause a poor user experience.

[0003] The coffee machine can also use flow meters, Hall sensors, etc. to detect the absence of water, but the use of these sensors will greatly increase the complexity and cost of the equipment. Summary of the invention

[0004] In view of the above-mentioned defects of the prior art, the object of the present invention is to provide an anti-dry pumping device, which can make a water absence judgment without changing the structure or adding sensors such as flow meters and Hall sensors, thereby controlling the water pump to stop working in time.

[0005] To achieve the above object, the present invention provides an anti-air pumping device, comprising a water tank, a water pump, a heater, a temperature sensor and a controller;

[0006] A water outlet is provided at the bottom of the water tank, and the temperature sensor is provided at the bottom of the water tank, adjacent to the water outlet;

[0007] The controller is connected with the temperature sensor, the water pump and the heater, and is used for:

[0008] Controlling the heater to heat;

[0009] After the heater stops heating, the water pump is controlled to work and perform a water pumping action;

[0010] When the water pump is working, the temperature data collected by the temperature sensor is continuously read to calculate the temperature drop slope at the current water outlet; then, a water shortage judgment is made based on the value of the temperature drop slope at the current water outlet; and when it is determined that there is no water in the water tank, the water pump is stopped.

[0011] Furthermore, the heater is a heating plate or a heating tube, which is arranged close to the outer side of the bottom of the water tank.

[0012] Furthermore, the heater is a heating plate, constituting a part of the bottom of the water tank.

[0013] Furthermore, the temperature sensor is an NTC temperature sensor.

[0014] Furthermore, the distance between the temperature sensor and the water outlet is no more than 30 mm.

[0015] Furthermore, the water outlet is provided with a drainage device, and the temperature sensor is arranged adjacent to the drainage outlet of the drainage device.

[0016] Furthermore, the distance between the temperature sensor and the water outlet is no more than 50 mm.

[0017] Furthermore, equipment using the anti-empty pumping device includes a coffee machine and a water dispenser.

[0018] The present invention also provides an anti-empty pumping method, which is applied to an anti-empty pumping device, the anti-empty pumping device comprising a water tank, a water pump, a heater, a temperature sensor and a controller; a water outlet is arranged at the bottom of the water tank, and the temperature sensor is arranged at the bottom of the water tank, adjacent to the water outlet;

[0019] The controller is connected to the temperature sensor, the water pump and the heater, and is used to perform:

[0020] Before the water pump works, the water in the water tank is heated to a predetermined temperature;

[0021] When the water pump is working, the temperature data collected by the temperature sensor is continuously read, and the temperature drop slope at the current water outlet is calculated;

[0022] The absence of water is determined based on the value of the temperature drop slope at the current water outlet, and the water pump is stopped when it is determined that there is no water in the water tank.

[0023] The present invention achieves the following technical effects:

[0024] The anti-empty pumping device of the present invention detects the temperature at the water outlet through a temperature sensor, and can make a water absence judgment without changing the structure or adding sensors such as a flow meter and a Hall sensor, thereby quickly stopping the water pump and avoiding the problem of poor user experience due to long empty pumping time and noisy noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a system diagram of the anti-air extraction control system of the coffee machine;

[0026] Figure 2 This is a schematic diagram of the installation position of the heating plate and NTC in one embodiment;

[0027] Figure 3 It is a schematic elevation diagram of a coffee machine water tank, a heating plate and an NTC installation in one embodiment;

[0028] Figure 4 is a schematic elevation diagram of a coffee machine water tank, a heating plate and an NTC installation according to another embodiment;

[0029] Figure 5 It is the temperature-time curve of natural cooling of NTC when NTC is not installed close to the water outlet;

[0030] Figure 6 It is the temperature-time curve of the NTC being rapidly cooled by the exhaust air flow when the NTC is set close to the water outlet;

[0031] Figure 7 It is a schematic diagram of the position of the drainage device of an embodiment. DETAILED DESCRIPTION

[0032] To further illustrate various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, ordinary technicians in this field should be able to understand other possible implementations and advantages of the present invention.

[0033] The present invention will now be further described with reference to the accompanying drawings and specific implementation methods.

[0034] Example 1

[0035] This embodiment provides an anti-empty suction device, specifically an electric coffee machine.

[0036] like Figures 1 to 4 As shown, this embodiment provides an example of an anti-vacuum system of a coffee machine. In this embodiment, a water outlet 3 is provided at the bottom of the water tank 1 of the coffee machine, and components such as a heater 2 and an NTC temperature sensor 4 are installed. The water outlet 3 is connected to a water pump 6 through a plastic pipe or a metal pipe, and the heater 2, the NTC temperature sensor 4, the water pump and the controller 5 (control panel) of the coffee machine are connected. The controller 5 monitors the temperature of the water in the water tank through the NTC temperature sensor 4, controls the heater 2 to heat, and controls the water pump to pump water after the heater 2 stops heating.

[0037] In a specific implementation, the heater 2 is a heating plate or a heating tube, which can be arranged close to the bottom outer side of the water tank 1 (such as Figure 4 As shown) or directly constitutes a part of the bottom of the water tank 1 (as shown Figure 3 shown).

[0038] In this embodiment, the installation position of the NTC temperature sensor 4 is restricted: Figure 3 and Figure 4As shown, the NTC temperature sensor 4 is installed at the bottom of the water tank 1 and is arranged close to the side of the water outlet 3 of the water tank 1. When the coffee machine is in use, it includes the steps of heating water and pumping water to extract coffee after stopping heating. When the step of pumping water to extract coffee is completed, the coffee machine will evacuate the water in the water tank. At this time, after the water pump evacuates the water, it will drive the flow of air around the NTC temperature sensor 4, and the airflow will accelerate the change of the air temperature around the NTC temperature sensor 4. Therefore, the water outlet airflow near the NTC temperature sensor 4 can be used to accelerate the change of the sensed temperature of the NTC temperature sensor 4, so as to accurately determine whether the water in the water tank has been pumped out.

[0039] Figure 5 It is the temperature-time curve of natural cooling of NTC when NTC is not installed close to the water outlet.

[0040] Among them, T1 is the highest temperature after the water heating stops; T2 is the temperature when the NTC starts to be exposed to the air after the water is pumped out; 0 to t1 is the time period when the NTC is in the water when the water in the water tank is not completely pumped out; t1 is the time when the NTC starts to be exposed to the air; t2 is the time when the NTC drops to T3 temperature (natural cooling).

[0041] Figure 6 This is a temperature-time curve of the NTC being rapidly cooled by the air flow when the NTC is set close to the water outlet. 0 to t1 is the time period when the NTC is in the water when the water in the water tank 1 is not completely pumped out, t1 is the time when the NTC begins to be exposed to the air; t3 is the time when the NTC drops to T3 temperature (the water pump pumps out the air at the water outlet of the water tank, driving the air flow around the NTC temperature sensor 4 to cool).

[0042] Depend on Figure 5 It can be seen that when the NTC is exposed to air and cooled naturally, the temperature drop rate detected will be faster than in water; Figure 6 It can be seen that the cooling rate of the NTC when it is exposed to the air and a water pump is used to pump away the air around the NTC will be faster than the cooling rate when it is normally exposed to natural cooling.

[0043] It can be seen from this that when the water tank 1 has water and then becomes empty, no matter where the NTC temperature sensor 4 is set at the bottom of the water tank 1, the value change of the temperature in the water tank 1 falling over time can be detected. However, if the NTC temperature sensor 4 is set far away from the water outlet 3, the NTC begins to be exposed to the air and is not affected by the airflow of the water outlet 3 and cools naturally. However, due to the high chamber temperature, the temperature around the NTC cools down too slowly, and the temperature change cannot be detected in a short time. On the contrary, when the temperature sensor 4 is set near the water outlet, the temperature-time curve at the water outlet will have a very obvious slope value change (the temperature drops faster when there is no water, and the slope value is larger). By recording and monitoring the temperature-time curve at the water outlet when the water pump is pumping water, by calculating the slope value of the temperature-time curve, it can be determined in a shorter time whether the water in the water tank has been pumped out according to the interval where the slope value is located.

[0044] When it is determined that the water in the water tank has been pumped out (i.e., the water pump is in an empty state), the water pump is stopped.

[0045] In addition to coffee machines, the anti-empty pumping device of this embodiment can also be applied to liquid heating equipment such as water dispensers. It can judge that there is no water without changing the structure of the equipment and adding sensors such as flow meters and Hall sensors. When the water pump is empty, the water pump can be stopped quickly. This avoids the problem of poor user experience due to long empty pumping time and noisy sound.

[0046] In this embodiment, in order to ensure that the water pump can effectively affect the temperature change around the NTC temperature sensor 4 when evacuating, the NTC temperature sensor 4 needs to be arranged near the water outlet 3 of the water tank 1. The distance between the NTC temperature sensor 4 and the water outlet can be set as needed. Preferably, the distance between the NTC temperature sensor 4 and the water outlet is not greater than 30 mm.

[0047] In this embodiment, the water outlet is a 360° omnidirectional water outlet, and the NTC temperature sensor is arranged on any side of the water outlet and can be affected by the liquid flow or air flow at the water outlet.

[0048] Example 2

[0049] like Figure 7 As shown, in a specific application, a drainage device 7 (drainage trough, drainage cover, etc.) can be set at the water outlet for drainage, and the NTC temperature sensor 4 is set near the drainage outlet of the drainage device 7. The water flow will pass through the NTC temperature sensor 4, and in the process from water to waterless in the water tank 1, the airflow passing through the NTC will be more concentrated, and the NTC temperature will drop faster when the water pump is empty. . In this way, the distance limit between the NTC temperature sensor 4 and the water outlet 3 can be relaxed. Preferably, the distance between the NTC temperature sensor 4 and the water outlet is not more than 50mm.

[0050] In the above embodiment, the temperature sensor adopts a temperature sensor such as an NTC temperature sensor that can measure the temperature quickly and in real time. The resistance value of the NTC temperature sensor decreases rapidly as the temperature rises, and the temperature can be collected quickly to reflect the temperature change in real time. This ensures that the controller stops the water pump in time when it detects that there is no water in the water tank.

[0051] The present invention also provides a method for preventing empty pumping, comprising:

[0052] Install the temperature sensor near the water tank outlet;

[0053] Before the water pump works, the water in the water tank is heated to a predetermined temperature;

[0054] When the water pump is working, the temperature data of the water tank outlet collected by the temperature sensor is continuously read, and the current temperature drop slope is calculated;

[0055] The absence of water is judged according to the value of the temperature drop slope, and when it is judged that there is no water in the water tank, the water pump is stopped.

[0056] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. An anti-empty pumping device, characterized in that: Includes water tank, water pump, heater, temperature sensor and controller; A water outlet is provided at the bottom of the water tank, and the temperature sensor is provided at the bottom of the water tank, adjacent to the water outlet; The controller is connected with the temperature sensor, the water pump and the heater, and is used for: Controlling the heater to heat; After the heater stops heating, the water pump is controlled to work and perform a water pumping action; When the water pump is working, the temperature data collected by the temperature sensor is continuously read to calculate the temperature drop slope at the current water outlet; then, the water-free state is judged according to the value of the temperature drop slope at the current water outlet; And when it is determined that there is no water in the water tank, the water pump is stopped.

2. The anti-empty device according to claim 1, characterized in that: The heater is a heating tube or a heating plate, and is arranged close to the outer side of the bottom of the water tank.

3. The anti-empty device according to claim 1, characterized in that: The heater is a heating plate, which constitutes a part of the bottom of the water tank.

4. The anti-empty device according to claim 1, characterized in that: The temperature sensor is an NTC temperature sensor.

5. The anti-air pumping device according to claim 1, characterized in that: The distance between the temperature sensor and the water outlet is no more than 30 mm.

6. The anti-air pumping device according to claim 1, characterized in that: The water outlet is provided with a drainage device, and the temperature sensor is arranged adjacent to the drainage outlet of the drainage device.

7. The anti-empty device according to claim 6, characterized in that: The distance between the temperature sensor and the water outlet is no more than 50 mm.

8. The anti-empty device according to any one of claims 1 to 7, characterized in that: Equipment using the anti-empty pumping device includes a coffee machine and a water dispenser.

9. A method for preventing empty pumping, characterized in that: Applied to an anti-air pumping device, the anti-air pumping device comprises a water tank, a water pump, a heater, a temperature sensor and a controller; a water outlet is arranged at the bottom of the water tank, and the temperature sensor is arranged at the bottom of the water tank, adjacent to the water outlet; The controller is connected to the temperature sensor, the water pump and the heater, and is used to perform: Before the water pump works, the water in the water tank is heated to a predetermined temperature; When the water pump is working, the temperature data collected by the temperature sensor is continuously read, and the temperature drop slope at the current water outlet is calculated; The absence of water is determined based on the value of the temperature drop slope at the current water outlet, and the water pump is stopped when it is determined that there is no water in the water tank.

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