A pressure relief water circulation system for a coffee maker

Abstract

The utility model discloses a kind of pressure relief water circulation systems of coffee machine, including water tank, water pump, heating pot, two-way temperature sensor, control loop, extraction head and pressure gauge. Water pump is connected with water tank, heating pot connects water pump export, two-way temperature sensor is located in heating pot water outlet. Control loop includes first, second, third three-way electromagnetic valve, forms closed loop connection, makes pressure relief water recycle through heating pot, reduces water consumption by more than 30%, and solves water pan maintenance and design contradiction. Pressure relief water is used as preheating water source, combined with the continuous heat preservation in heating pot, keep pipeline water temperature constant, avoid extraction water temperature fluctuation. Second three-way electromagnetic valve is connected with pressure gauge and extraction head in parallel, residual pressure in pressure gauge is released synchronously when pressure relief, realize that pressure gauge is automatically zeroed after pressure relief, provide intuitive safety state indication, eliminate the operation risk caused by user misjudgment pressure.

Description

Technical Field

[0001] This utility model relates to the technical field of coffee machines, and in particular to a pressure relief water circulation system for a coffee machine. Background Technology

[0002] After an espresso machine extracts coffee using a water pump, if the residual high pressure in the piping is not released in time, there is a safety hazard of burns from high-temperature, high-pressure steam when the user operates the extraction head. Current mainstream solutions employ automatic pressure relief mechanisms to drain the pressure-relieved water into an external drip tray. However, this technology has significant drawbacks:

[0003] 1. The pressure relief water is directly discharged into the water collection pan, causing it to fill up quickly. Users need to clean it frequently, which seriously affects the user experience, especially in high-frequency use scenarios.

[0004] 2. To accommodate the pressure relief water, the water collection tray needs to be designed with a large capacity, which not only occupies the space of the machine body and damages the overall appearance, but also increases the hard-to-clean areas.

[0005] 3. The release of pressure water causes additional water to be consumed for each extraction, requiring frequent refilling of the water tank, which is especially noticeable when making multiple cups of coffee in a row. Utility Model Content

[0006] To overcome at least one of the defects described in the prior art, this utility model provides a pressure relief water circulation system for a coffee machine. This solves the contradiction between user experience and mechanical design inherent in traditional coffee machine pressure relief technologies.

[0007] The technical solution adopted by this utility model to solve its problem is:

[0008] A pressure relief water circulation system for a coffee machine includes: a water tank; a water pump, the inlet of which is connected to the water tank; a heating pot, the inlet of which is connected to the outlet of the water pump; a two-way temperature sensor disposed at the outlet of the heating pot; a control circuit including a first three-way solenoid valve, a second three-way solenoid valve, and a third three-way solenoid valve, wherein the inlet of the first three-way solenoid valve is connected to the two-way temperature sensor, the top interface of the first three-way solenoid valve is connected to the inlet of the heating pot via the second three-way solenoid valve, the outlet of the first three-way solenoid valve is connected to the inlet of the third three-way solenoid valve, and a pressure relief circuit forming a closed loop is provided between the top interface of the third three-way solenoid valve and the inlet of the second three-way solenoid valve; an extraction head connected to the outlet of the third three-way solenoid valve; and a pressure gauge connected to the outlet of the third three-way solenoid valve, with the extraction head connected in parallel with the pressure gauge.

[0009] By adopting the above solution, and through a closed-loop connection between the control loop, the pressure relief loop, and the heating pot, the pressure relief water is recycled and reused in the heating pot, completely avoiding the need for pressure relief water to be discharged into the water collection pan, thus resolving the conflict between water collection pan maintenance and design. The pressure relief water serves as a preheated water source for the next extraction, reducing the net water consumption per extraction by more than 30% compared to traditional solutions, significantly reducing the frequency of water replenishment operations for users. Combined with the continuous heat preservation of the pressure relief water within the heating pot, the water temperature in the pipeline is ensured to remain constant within the set range, avoiding the temperature fluctuations in the extraction water caused by pipeline cooling after traditional pressure relief. A second three-way pipe connects the pressure gauge and the extraction head in parallel, simultaneously releasing the residual pressure in the pressure gauge during pressure relief mode, allowing the pressure gauge to automatically return to zero after pressure relief, providing an intuitive safety status indication and eliminating operational risks caused by user misjudgment of pressure.

[0010] Furthermore, it also includes a first three-way pipe, the three ports of which are respectively connected to the outlet end of the water pump, the inlet end of the heating pot, and the outlet end of the second three-way solenoid valve.

[0011] By adopting the above solution, the first tee pipe, as a key component for water flow distribution, can efficiently guide the water output from the water pump to the heating element or the circulation loop. This design simplifies the water flow path, reduces piping complexity, and makes the water flow smoother.

[0012] Furthermore, it also includes a second three-way pipe, the three ports of which are respectively connected to the outlet end of the third three-way solenoid valve, the pressure gauge, and the extraction head.

[0013] By adopting the above scheme, the second three-way pipe is used as a connection node, enabling the system to simultaneously meet the needs of pressure gauge monitoring, extraction head water output, and pressure relief circuit.

[0014] Furthermore, it also includes a steam branch, which includes a steam pipe and a steam switch, and the steam branch is connected to the pipeline between the first three-way solenoid valve and the third three-way solenoid valve.

[0015] By adopting the above solution, not only is the pressure relief water circulation function achieved, but steam supply capability is also provided. Connecting the steam branch to the pipeline of the pressure relief water circulation system makes full use of existing space and avoids additional pipeline layout and space occupation.

[0016] Furthermore, it also includes a third three-way pipe, the three ports of which are respectively connected to the outlet end of the first three-way solenoid valve, the inlet end of the third three-way solenoid valve, and the steam branch.

[0017] By adopting the above scheme, water can flow directly from the outlet of the first three-way solenoid valve to the inlet of the third three-way solenoid valve, or flow through the steam branch to the component requiring steam. This design provides flexible water flow path selection, meeting the needs of the coffee machine in different operating modes.

[0018] Furthermore, a return valve is connected to the outlet end of the water pump, and a return pipe is provided between the return valve and the water tank.

[0019] By adopting the above solution, when the system does not require a large amount of water, the water flow can return to the water tank through the return pipe, maintaining the water flow balance in the system and improving the system's stability.

[0020] Furthermore, when the water pump starts working for the first time, the water flows from the water tank through the water pump, the heating element, the two-way temperature sensor, the first three-way solenoid valve, and the third three-way solenoid valve before reaching the extraction head.

[0021] By adopting the above solution, both the efficient operation of the coffee machine and the quality and taste of the coffee are guaranteed.

[0022] Furthermore, after extraction by the extraction head, the water in the extraction head and the water in the second outlet of the first three-way solenoid valve flow sequentially through the third three-way solenoid valve and the second three-way solenoid valve before entering the heating pot.

[0023] By adopting the above solution, automatic pressure relief can be achieved, allowing water to flow back to the heating pot for the next use. This helps optimize energy utilization and reduce energy waste.

[0024] Furthermore, when the water pump operates continuously and dispenses water, the water flows from the water tank through the water pump, the heating element, the two-way temperature sensor, the first three-way solenoid valve, and the third three-way solenoid valve in sequence before reaching the extraction head. At the same time, a circulating water path is formed between the heating pump, the two-way temperature sensor, the first three-way solenoid valve, and the second three-way solenoid valve.

[0025] By adopting the above method, the heating speed of the water can be increased by mixing the fresh water with the return water, which can maximize the temperature during coffee extraction and thus improve the extraction effect.

[0026] Furthermore, when milk frothing is needed, water flows from the water tank through the water pump into the heating pot, where the heating pot converts the water into steam, which then flows sequentially through the two-way temperature sensor, the first three-way solenoid valve, and the steam switch before entering the steam pipe.

[0027] By adopting the above solution, the coffee machine can quickly and accurately provide steam at the appropriate temperature when milk frothing is needed, thus meeting the diverse needs of users.

[0028] In summary, the pressure relief water circulation system for a coffee machine provided by this utility model has the following technical effects:

[0029] 1. By recycling the depressurized water back to the heating pot, the direct discharge of the depressurized water into the water collection pan is avoided, thereby reducing the hassle of users frequently cleaning the water collection pan. Especially in high-frequency use scenarios, this significantly improves the user experience, saves the amount of water used during extraction, reduces the need for users to frequently add water to the water tank, and further improves the convenience of use.

[0030] 2. The traditional large-capacity water tray design has been eliminated, which makes more reasonable use of the space in the coffee machine body, improves the overall appearance, reduces cleaning dead corners, and makes the coffee machine design more refined and reduces manufacturing costs.

[0031] 3. Depressurized water is used as a preheated water source for the next extraction, which reduces the net water consumption per extraction compared to the traditional method and significantly improves the efficiency of water resource utilization.

[0032] 4. The depressurized water is kept warm in the heating pot, ensuring that the water temperature in the pipeline remains constant within the set range. This avoids the problem of water temperature fluctuation caused by pipeline cooling after traditional depressurization, thereby improving the quality of extracted coffee.

[0033] 5. The pressure gauge and extraction head are connected in parallel via a second three-way pipe. In the pressure relief mode, the residual pressure in the pressure gauge is released simultaneously, and the pressure gauge automatically returns to zero after the pressure relief is completed. This provides an intuitive safety status indication and eliminates the operational risks caused by users misjudging the pressure. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the water channel routing structure during extraction according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic diagram of the water path structure during pressure relief according to an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of the water recirculation direction structure according to an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of the water channel structure for simultaneous extraction and reflux in an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the water path structure during the milk frothing function of this utility model embodiment.

[0039] The meanings of the reference numerals in the attached diagram are as follows: 1. Water tank; 2. Water pump; 3. Heating pot; 4. Two-way temperature sensor; 5. Control circuit; 51. First three-way solenoid valve; 52. Second three-way solenoid valve; 53. Third three-way solenoid valve; 6. Pressure relief circuit; 7. Extraction head; 8. Pressure gauge; 9. First three-way pipe; 10. Second three-way pipe; 11. Third three-way pipe; 12. Steam branch; 121. Steam pipe; 122. Steam switch; 13. Return pipe; 14. Return valve; 15. Circulating water circuit. Detailed Implementation

[0040] To better understand and implement this invention, the technical solutions in the embodiments of this invention will be clearly and completely described and discussed below with reference to the accompanying drawings. Obviously, what is described here is only a part of the examples of this invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the protection scope of this invention.

[0041] To facilitate understanding of the embodiments of this utility model, further explanations and descriptions will be provided below with reference to the accompanying drawings and specific embodiments. These embodiments do not constitute a limitation on the embodiments of this utility model.

[0042] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" 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 utility model 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 utility model.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0044] See Embodiment 1 of this utility model. Figures 1-5The diagram discloses a pressure relief water circulation system for a coffee machine, comprising a water tank 1, a water pump 2, a heating element 3, a two-way temperature sensor 4, a control circuit 5, an extraction head 7, and a pressure gauge 8. The inlet end of the water pump 2 is connected to the water tank 1, and the inlet end of the heating element 3 is connected to the outlet end of the water pump 2. The two-way temperature sensor 4 is located at the outlet of the heating element 3. The control circuit 5 includes a first three-way solenoid valve 51, a second three-way solenoid valve 52, and a third three-way solenoid valve 53. The inlet end of the first three-way solenoid valve 51 is connected to the two-way temperature sensor 4, and the top interface end of the first three-way solenoid valve 51 connects to the inlet end of the heating element 3 via the second three-way solenoid valve 52. The outlet end of the first three-way solenoid valve 51 is connected to the inlet end of the third three-way solenoid valve 53. A closed-loop pressure relief circuit 6 is provided between the top interface end of the third three-way solenoid valve 53 and the inlet end of the second three-way solenoid valve 52. The extraction head 7 is connected to the outlet end of the third three-way solenoid valve 53. The pressure gauge 8 is connected to the outlet end of the third three-way solenoid valve 53, and the extraction head 7 and the pressure gauge 8 are connected in parallel. Through the closed-loop connection of the control circuit 5, the pressure relief circuit 6 and the heating pot 3, the pressure relief water is recycled and reused through the heating pot 3, completely avoiding the need for pressure relief water to be discharged into the water collection pan, and solving the contradiction between water collection pan maintenance and design. The pressure relief water is used as a preheated water source for the next extraction, reducing the net water consumption of a single extraction by more than 30% compared with the traditional solution, and significantly reducing the frequency of water replenishment operations by users. By combining the continuous heat preservation of the depressurized water within the heating pot 3, the water temperature in the pipeline is ensured to remain constant within the set range, avoiding the temperature fluctuation problem of the extraction water caused by pipeline cooling after traditional depressurization. The pressure gauge 8 and extraction head 7 are connected in parallel via the second three-way pipe 10. During depressurization mode, the residual pressure in the pressure gauge 8 is released simultaneously, allowing the pressure gauge 8 to automatically return to zero after depressurization, providing an intuitive safety status indication and eliminating operational risks caused by user misjudgment of pressure.

[0045] In this embodiment 1, a first three-way pipe 9 and a second three-way pipe 10 are also included. The three ports of the first three-way pipe 9 are respectively connected to the outlet of the water pump 2, the inlet of the heating pot 3, and the outlet of the second three-way solenoid valve 52. The three ports of the second three-way pipe 10 are respectively connected to the outlet of the third three-way solenoid valve 53, the pressure gauge 8, and the extraction head 7. As key components for water flow distribution, the first three-way pipe 9 and the second three-way pipe 10 can efficiently guide the water output from the water pump 2 to the heating pot 3 or the circulation loop. This design simplifies the water flow path, reduces pipeline complexity, and makes the water flow smoother. The second three-way pipe 10, as a connection node, enables the system to simultaneously meet the needs of pressure gauge 8 monitoring, water output from the extraction head 7, and pressure relief loop 6.

[0046] In some embodiments, to enhance the milk frothing function of the coffee machine, a steam branch 12 and a third three-way pipe 11 are also included. The steam branch 12 includes a steam pipe 121 and a steam switch 122, and is connected to the pipeline between the first three-way solenoid valve 51 and the third three-way solenoid valve 53. The three ports of the third three-way pipe 11 are respectively connected to the outlet of the first three-way solenoid valve 51, the inlet of the third three-way solenoid valve 53, and the steam branch 12. The steam branch 12 not only has a pressure relief water circulation function but also a steam supply capability. Connecting the steam branch 12 to the pipeline of the pressure relief water circulation system makes full use of existing space and avoids additional pipeline layout and space occupation. The third three-way pipe 11 allows water to flow directly from the outlet of the first three-way solenoid valve 51 to the inlet of the third three-way solenoid valve 53, or through the steam branch 12 to components requiring steam. This design provides flexible water flow path selection, meeting the needs of the coffee machine in different operating modes.

[0047] Optionally, in some embodiments, to facilitate the regulation of water flow, a return valve 14 is connected to the outlet end of the water pump 2, and a return pipe is provided between the return valve 14 and the water tank 1. When the system does not require a large amount of water, the water flow can return to the water tank 1 through the return pipe, maintaining the water flow balance within the system and improving the system's stability.

[0048] The working principle and water flow path are as follows:

[0049] See Figure 1 As shown, when a consumer uses the coffee extraction machine for the first time, water pump 2 starts working and pumps water into water tank 1. At this time, the second three-way solenoid valve 52 is fully closed. Water flows from water tank 1 through water pump 2, heating element 3, two-way temperature sensor 4, first three-way solenoid valve 51, and third three-way solenoid valve 53 before reaching extraction head 7. At this time, the top interfaces of first three-way solenoid valve 51 and third three-way solenoid valve 53 are both closed, allowing water to enter third three-way pipe 11. Since steam switch 122 is closed, water passes through third three-way solenoid valve 53 into second three-way pipe 10, and then enters extraction head 7 to extract coffee. Pressure gauge 8 displays the extraction pressure. At this point, extraction is complete, ensuring both efficient operation of the coffee machine and the quality and taste of the coffee.

[0050] See Figure 2As shown, when extraction is complete, the channels of the third three-way solenoid valve 53 are fully open, and the first three-way solenoid valve 51 is fully closed. Water from the outlet of the first three-way solenoid valve 51 and pressurized water remaining in the extraction coffee tubing flow to the second outlet of the third three-way solenoid valve 53, thus completing automatic pressure relief. Pressure gauge 8 returns to zero, and pressure relief in the extraction head 7 ensures safety. At this point, the second outlet of the second three-way solenoid valve 52 closes, and the depressurized water flows through the first three-way pipe 9 back into the heating pot 3 for reheating, ready for the next use. This ensures that the water in the extraction head 7 and the water in the outlet channel of the first three-way solenoid valve 51 flow sequentially through the third three-way solenoid valve 53 and the second three-way solenoid valve 52 before entering the heating pot 3, achieving automatic pressure relief and returning the water to the heating pot 3 for the next use. This helps optimize energy utilization and reduce energy waste.

[0051] After extraction, there are two scenarios. The first is that after a consumer finishes extracting one cup, they will take a short break and will not immediately proceed to extracting the next cup or frothing the milk. (See [link / reference]). Figure 3 As shown, when the returning water enters the heating chamber, it is reheated and flows out through the two-way temperature sensor 4 for temperature sensing. Then, when it passes through the first three-way solenoid valve 51, the top interface end and the inlet end of the first three-way solenoid valve 51 are open, and the outlet end is closed. When the water passes through the second three-way solenoid valve 52, the top interface end and the outlet end of the second three-way solenoid valve 52 are open. The water then flows back to the heating chamber through the first three-way pipe 9. This ensures that the depressurized water remains in a circulating state, ready for the next use. The extraction effect will not be affected by the low-temperature water entering the extraction pipeline. In this way, even if the power is turned off after the consumer has finished extracting coffee, the extraction pipeline will be in a waterless state, and the extraction effect will not be affected during the next extraction.

[0052] The second scenario is when a consumer needs to immediately brew another cup of coffee after finishing the first, such as... Figure 5As shown, water pump 2 starts working, drawing water into water tank 1, which, along with the return water, enters the heating pot 3 for heating. When the heated water enters the two-way temperature sensor 4, if the mixed water is not heated to the extraction temperature, the first three-way solenoid valve 51 is completely closed. This ensures that the water in the heating pot 3 is heated to the extraction temperature before the inlet and outlet channels of the first three-way solenoid valve 51 open, while the top interface closes. At this time, the water flows from water tank 1 through water pump 2, heating pot 3, two-way temperature sensor 4, first three-way solenoid valve 51, and third three-way solenoid valve 53 before reaching the extraction head 7. When the water enters the second three-way pipe 10, due to the steam switch 122 being closed, the water flows to the third three-way solenoid valve 53. At this time, the top interface of the third three-way solenoid valve 53 is closed, while the left and right inlet and outlet channels are open, allowing the water to enter the third three-way pipe 11. Then, the water enters the extraction head 7 to extract coffee, and the pressure gauge 8 displays the extraction pressure. This ensures the maximum temperature during coffee extraction, thereby improving the extraction effect. Simultaneously, the returned water from the previous run will flow back into the heating pot 3, enabling the heating pump to form a circulating water path 15 between the two-way temperature sensor 4, the first three-way solenoid valve 51, and the second three-way solenoid valve 52. The mixing and heating of fresh water and returned water can increase the heating speed, thus maximizing the temperature during coffee extraction and improving the extraction effect.

[0053] See Figure 4 As shown, when the coffee machine finishes extraction and steam is needed for milk frothing, water pump 2 starts working, drawing water from water tank 1 and the return water into the heating chamber for heating. Once the heating chamber heats the water into steam, it enters the two-way temperature sensor 4. At this point, the first three-way solenoid valve 51 opens the left and right inlet and outlet channels; otherwise, heating would continue. Meanwhile, the third three-way solenoid valve 53 is fully closed, and the steam switch 122 is open. Steam then flows from the pipe into the steam pipe 121 for milk frothing. Water flows from water tank 1 through water pump 2 into the heating chamber 3. The heating chamber 3 converts the water into steam, which then flows sequentially through the two-way temperature sensor 4, the first three-way solenoid valve 51, and the steam switch 122 before entering the steam pipe 121. This allows the coffee machine to quickly and accurately provide steam at the appropriate temperature when milk frothing is needed, meeting diverse user needs. This process also activates the circulating water circuit 15.

[0054] This utility model also relates to a method for controlling the pressure relief water circulation of a coffee machine, which employs the pressure relief water circulation system of the coffee machine and includes the following five control methods and steps:

[0055] First extraction mode control:

[0056] S101: Start water pump 2, close the top interface of the second three-way solenoid valve 52, that is, block the flow to the pressure relief circuit 6, open the inlet and outlet channels of the first three-way solenoid valve 51, that is, the water flows from the two-way temperature sensor 4 to the third three-way solenoid valve 53, and at the same time open the inlet and outlet channels of the third three-way solenoid valve 53, that is, the water flows to the extraction head 7.

[0057] S102: The water flow path is as follows: water tank 1, water pump 2, heating pot 3, two-way temperature sensor 4, first three-way solenoid valve 51, third three-way solenoid valve 53, second three-way pipe 10, extraction head 7 and pressure gauge 8. Among them, the heating pot 3 heats the water flow, the two-way temperature sensor 4 detects the water temperature, the extraction head 7 extracts coffee, and the pressure gauge 8 displays the real-time pressure. In some embodiments, optionally, the two-way temperature sensor 4 and the pressure gauge 8 are linked. When an abnormal water temperature or pressure is detected, an alarm device can be added to automatically trigger the pressure relief mode and alarm.

[0058] S103: When the two-way temperature sensor 4 detects that the water temperature has reached the set threshold, it maintains heating and completes the extraction. Specifically, the two-way temperature sensor 4 monitors the water temperature in real time. If it is lower than the set threshold, such as 92°C, it triggers the heating pot 3 to continue heating. When the water temperature reaches the threshold, it maintains the heating power and completes the coffee extraction.

[0059] Pressure relief mode control:

[0060] S201: After extraction, close the outlet end of the first three-way solenoid valve 51 to block the flow to the extraction head 7, open its top interface end to connect the pressure relief circuit 6; at the same time, open the inlet and outlet channels of the second three-way solenoid valve 52 to allow the pressure relief water to flow back to the heating pot 3, and open the top interface and outlet channels of the third three-way solenoid valve 53 to connect the pressure relief circuit 6.

[0061] S202: The pressure relief water flow path is as follows: extraction head 7 and residual high pressure water in the pipeline, third three-way solenoid valve 53, pressure relief circuit 6, second three-way solenoid valve 52, first three-way pipe 9, heating pot 3.

[0062] S203: Synchronously releases residual pressure in pressure gauge 8 until the pointer of pressure gauge 8 returns to zero, providing a safety status indication; during pressure relief, it synchronously controls the outlet end of the second three-way solenoid valve 52 to close, so as to control the pressure relief water to flow back to the heating pot 3 in one direction through the pressure relief circuit 6, which can realize automatic pressure relief and return the water to the heating pot 3 for the next use. This helps to optimize energy utilization and reduce energy waste.

[0063] Circulating heat preservation mode control:

[0064] S301: In the non-extraction state, open the top interface and inlet channel of the first three-way solenoid valve 51, that is, the water flows from the two-way temperature sensor 4 to the pressure relief circuit 6, and at the same time open the inlet and outlet channels of the second three-way solenoid valve 52 to allow the water to return to the heating pot 3.

[0065] S302: The circulating water circuit 15 includes a heating pot 3, a two-way temperature sensor 4, a first three-way solenoid valve 51, a second three-way solenoid valve 52, and the heating pot 3 connected in sequence to maintain a constant water temperature;

[0066] Step S303: The two-way temperature sensor 4 monitors the water temperature in real time. If it is lower than the set threshold, it triggers the heating pot 3 to heat the water and drives the water pump 2 to work intermittently, maintaining the continuous flow of the circulating water circuit 15 and ensuring a constant water temperature in the pipes. The mixing and heating of fresh water and return water can increase the heating speed, thus maximizing the temperature during coffee extraction and improving the extraction effect.

[0067] Continuous extraction mode control:

[0068] S401: Start water pump 2 to inject new water, which mixes with the return water in the circulating water circuit 15 and heats it in the heating pot 3;

[0069] S402: The two-way temperature sensor 4 detects the mixed water temperature. If it does not reach the set threshold, the circulating water path 15 is kept running until the water temperature reaches the standard. When the water temperature reaches the standard, the water flow path S102 is switched to the first extraction mode for continuous extraction. The new water and the return water are mixed and heated to shorten the heating time and avoid water temperature fluctuations caused by the cooling of the pipeline after traditional depressurization, thus improving the quality of continuous extraction.

[0070] Steam mode control:

[0071] S501: Close all channels of the third three-way solenoid valve 53 to isolate the extraction pipeline and turn on the steam switch 122;

[0072] S502: The water flow path is as follows: water tank 1, water pump 2, heating pot 3, two-way temperature sensor 4, first three-way solenoid valve 51, steam branch 12, steam pipe 121, where steam pipe 121 outputs steam for milk frothing.

[0073] Step S503: Steam is continuously generated and output through heating pot 3. During steam generation, the inlet and outlet channels of the first three-way solenoid valve 51 remain open, while the third three-way solenoid valve 53 is completely closed to isolate the extraction pipeline, thereby improving control over the extraction pipeline. The steam output pressure and flow rate are controlled by adjusting the heating power of heating pot 3 and the opening degree of steam switch 122. The extraction pipeline is completely isolated during steam generation to prevent steam from interfering with the extraction system, achieving multi-functional integrated control.

[0074] In summary, the pressure relief water circulation system for a coffee machine provided by this utility model has the following technical effects:

[0075] 1. By recycling the depressurized water to the heating pot 3, the direct discharge of the depressurized water into the water collection pan is avoided, thereby reducing the trouble of users frequently cleaning the water collection pan. Especially in high-frequency use scenarios, it significantly improves the user experience, saves the amount of water used during extraction, reduces the need for users to frequently add water to the water tank 1, and further improves the convenience of use.

[0076] 2. The traditional large-capacity water tray design has been eliminated, which makes more reasonable use of the space in the coffee machine body, improves the overall appearance, reduces cleaning dead corners, and the reduced water tray capacity makes the coffee machine design more refined and reduces manufacturing costs.

[0077] 3. Depressurized water is used as a preheated water source for the next extraction, which reduces the net water consumption per extraction compared to traditional methods and significantly improves the efficiency of water resource utilization.

[0078] 4. The depressurized water is kept warm in the heating pot 3, ensuring that the water temperature in the pipeline remains constant within the set range. This avoids the problem of temperature fluctuations in the extraction water caused by the cooling of the pipeline after depressurization, thereby improving the quality of the extracted coffee.

[0079] 5. The pressure gauge 8 and the extraction head 7 are connected in parallel through the second three-way pipe 10. In the pressure relief mode, the residual pressure in the pressure gauge 8 is released simultaneously, so that the pressure gauge 8 automatically returns to zero after the pressure relief is completed. This provides an intuitive safety status indication and eliminates the operational risks caused by users misjudging the pressure.

[0080] The technical means disclosed in this utility model are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

Claims

1. A pressure relief water circulation system for a coffee machine, characterized in that, include: Water tank (1); A water pump (2), the inlet end of which is connected to the water tank (1); A heating pot (3), the inlet end of which is connected to the outlet end of the water pump (2); Two-way temperature sensor (4), the two-way temperature sensor (4) is set at the water outlet of the heating pot (3); The control circuit (5) includes a first three-way solenoid valve (51), a second three-way solenoid valve (52), and a third three-way solenoid valve (53). The inlet end of the first three-way solenoid valve (51) is connected to the two-way temperature sensor (4). The top interface end of the first three-way solenoid valve (51) is connected to the inlet end of the heating pot (3) after passing through the second three-way solenoid valve (52). The outlet end of the first three-way solenoid valve (51) is connected to the inlet end of the third three-way solenoid valve (53). A pressure relief circuit (6) forming a closed loop is provided between the top interface end of the third three-way solenoid valve (53) and the inlet end of the second three-way solenoid valve (52). Extraction head (7), which is connected to the outlet end of the third three-way solenoid valve (53); Pressure gauge (8) is connected to the outlet end of the third three-way solenoid valve (53), and the extraction head (7) is connected in parallel with the pressure gauge (8).

2. The pressure relief water circulation system for a coffee machine according to claim 1, characterized in that, It also includes a first three-way pipe (9), the three ports of which are respectively connected to the outlet end of the water pump (2), the inlet end of the heating pot (3), and the outlet end of the second three-way solenoid valve (52).

3. The pressure relief water circulation system for a coffee machine according to claim 1, characterized in that, It also includes a second three-way pipe (10), the three ports of which are respectively connected to the outlet end of the third three-way solenoid valve (53), the pressure gauge (8) and the extraction head (7).

4. The pressure relief water circulation system of a coffee machine according to claim 1, characterized in that, It also includes a steam branch (12), which includes a steam pipe (121) and a steam switch (122). The steam branch (12) is connected to the pipeline between the first three-way solenoid valve (51) and the third three-way solenoid valve (53).

5. The pressure relief water circulation system of a coffee machine according to claim 4, characterized in that, It also includes a third three-way pipe (11), the three ports of which are respectively connected to the outlet end of the first three-way solenoid valve (51), the inlet end of the third three-way solenoid valve (53), and the steam branch (12).

6. The pressure relief water circulation system of a coffee machine according to claim 1, characterized in that, The outlet end of the water pump (2) is connected to a return valve (14), and a return pipe is provided between the return valve (14) and the water tank (1).

7. The pressure relief water circulation system of a coffee machine according to claim 1, characterized in that, When the water pump (2) starts working for the first time, the water flows from the water tank (1) through the water pump (2), the heating pot (3), the two-way temperature sensor (4), the first three-way solenoid valve (51), and the third three-way solenoid valve (53) before reaching the extraction head (7).

8. The pressure relief water circulation system of a coffee machine according to claim 7, characterized in that, After extraction by the extraction head (7), the water in the extraction head (7) and the water in the second outlet of the first three-way solenoid valve (51) flow sequentially through the third three-way solenoid valve (53) and the second three-way solenoid valve (52) before entering the heating pot (3).

9. The pressure relief water circulation system of a coffee machine according to claim 7, characterized in that, When the water pump (2) works continuously to produce water, the water flows from the water tank (1) through the water pump (2), the heating pot (3), the two-way temperature sensor (4), the first three-way solenoid valve (51), and the third three-way solenoid valve (53) in sequence to the extraction head (7). At the same time, the heating pump forms a circulating water path (15) with the two-way temperature sensor (4), the first three-way solenoid valve (51), and the second three-way solenoid valve (52).

10. The pressure relief water circulation system of a coffee machine according to claim 4, characterized in that, When milk needs to be frothed, water flows from the water tank (1) through the water pump (2) into the heating pot (3). The heating pot (3) converts the water into steam, which then flows through the two-way temperature sensor (4), the first three-way solenoid valve (51), and the steam switch (122) before entering the steam pipe (121).

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