Method and system for making milk froth for a coffee machine

Abstract

This invention discloses a method and system for making milk foam in a coffee machine, belonging to the field of coffee machine technology. Existing coffee machines are prone to steam spraying and milk splashing during the initial stage of milk emulsification. This invention addresses this by first filling the milk delivery pipe between the milk tank and the milk frother with water or milk during the initial stage of milk emulsification to eliminate air in the pipe. Then, steam is delivered to the milk frother. Once the steam enters the milk frother, it encounters milk or water, not air, thus avoiding the generation of high steam pressure in the emulsification zone during the initial steam spraying stage. This shortens the duration of steam pressure, thereby preventing or reducing milk splashing. Subsequently, the milk frother draws milk from the milk tank through the delivery pipe and emulsifies the drawn milk into milk foam, improving the user experience, avoiding the risk of burns, and keeping the coffee machine's exterior clean.

Description

Technical Field

[0001] This invention pertains to coffee machine technology, specifically relating to a method and system for making milk foam for a coffee machine. Background Technology

[0002] To improve the flavor of coffee beverages, milk products such as milk foam (or simply milk foam) are often added when making coffee with a coffee machine. Milk foam is created using a milk frother. Specifically, steam is supplied to the milk frother, generating negative pressure that draws milk from the milk tank through a milk delivery tube. The milk is then emulsified into milk foam in the milk frother and output to be added to the coffee beverage, creating milk coffee (milk coffee).

[0003] However, a fatal problem exists in the current milk coffee making process: when the user presses the milk coffee function button, steam is input into the milk frother and ejected from it. Since the milk delivery tube connecting the milk frother and the milk tank is usually air, it takes time for milk to be drawn from the milk tank into the mixing zone of the milk frother. During this period, high-temperature steam is ejected separately from the milk frother, and it is easy to generate high steam pressure. After the milk is emulsified in the milk frother, it is prone to splashing. This phenomenon not only affects the user experience and poses a risk of scalding the user, but also significantly affects the cleanliness of the coffee machine's exterior. Summary of the Invention

[0004] The technical problem to be solved and the technical task proposed by the present invention is to overcome the defects of existing coffee machines in the initial stage of milk foaming and steam spraying and milk splashing, and to provide a method and system for making milk foam for coffee machines, so as to weaken or eliminate the phenomenon of steam spraying and milk splashing, improve the user experience, avoid the risk of burns, and keep the coffee machine shell clean.

[0005] To achieve the above objectives, the milk frothing method for the coffee machine of the present invention includes the following steps:

[0006] (1) Fill the milk delivery tube between the milk tank and the milk frother with water or milk;

[0007] (2) Steam is supplied to the milk frother, which draws milk from the milk tank through the milk delivery pipe and emulsifies the milk into milk foam.

[0008] This method involves first filling the milk delivery tube between the milk tank and the milk frother with water or milk at the initial stage of milk emulsification to eliminate air in the delivery tube. Then, steam is delivered to the milk frother. Once the steam enters the milk frother, it encounters milk or water instead of air, thus avoiding the generation of large steam pressure in the emulsification zone at the beginning of steam injection and shortening the existence time of steam pressure. This prevents or reduces the amount and intensity of milk splashing. Subsequently, the milk frother draws milk from the milk tank through the delivery tube and emulsifies the drawn milk into milk foam, improving the user experience, avoiding the risk of burns, and keeping the coffee machine's exterior clean.

[0009] To accurately fill the milk delivery tube with water or milk, and to avoid excessive delivery causing water or milk to overflow or insufficient delivery resulting in air remaining in the milk delivery tube, a first water pump supplies steam to the milk frother, while a second water pump fills the milk delivery tube with water or milk.

[0010] In one embodiment, a second water pump is connected to a water tank and a milk delivery pipe to fill the milk delivery pipe with water stored in the water tank. In this case, a one-way valve is provided at the connection between the milk delivery pipe and the milk tank. The one-way valve controls the milk in the milk tank to flow only from the milk tank to the milk delivery pipe. The outlet end of the second water pump is connected to the outlet end of the one-way valve to prevent the water delivered by the second water pump from flowing into the milk tank.

[0011] In another embodiment, a second water pump is connected to the milk tank and the milk delivery pipe to pump milk from the milk tank into the milk delivery pipe. In this case, a one-way valve is provided at the connection between the milk delivery pipe and the milk tank. The one-way valve controls the milk in the milk tank to flow only from the milk tank to the milk delivery pipe. The outlet end of the second water pump is connected to the outlet end of the one-way valve to prevent the milk pumped by the second water pump from flowing into the milk tank.

[0012] To simplify the structure and save on parts, the same water pump is used to fill the milk delivery pipe with water and deliver steam to the milk frother in stages. Specifically, the first water pump fills the milk delivery pipe with water first and then delivers steam to the milk frother.

[0013] In order to avoid milk residue buildup and hygiene problems in the milk delivery tube and milk foam generator after emulsification, the method includes the following steps: (3) automatically flushing the milk delivery tube and milk foam generator with water after emulsification.

[0014] To prevent the water or milk in the milk delivery tube from being lost, the milk delivery tube is stopped when it is filled with water or milk, and the start step (2) is initiated.

[0015] To achieve the above objectives, the system for realizing the milk foam making method of the present invention includes a water tank, a first water pump, a heater and a milk foam generator connected sequentially according to the direction of water flow. The milk foam generator is connected to a milk tank via a milk delivery pipe. The system is characterized in that the milk delivery pipe is connected to a filling pipe for filling the milk delivery pipe with water or milk before the milk foam generator draws milk from the milk tank via the milk delivery pipe.

[0016] In one embodiment of the present invention, the filling pipeline includes a switching valve, which includes a first inlet, a second inlet, and an outlet. The first inlet is used to input pressurized water, the second inlet is used to draw milk from the milk tank, and the outlet is connected to the milk delivery pipe. The switching valve is configured such that either the first inlet or the second inlet is connected to the outlet to allow pressurized water or milk to flow out from the outlet. The second inlet and the outlet are kept open to allow the milk frother to draw milk from the milk tank via the milk delivery pipe. When pressurized water is supplied to the first inlet, the valve switches to connect the first inlet and the outlet to fill the milk delivery pipe with water or to clean the milk delivery pipe and the milk frother.

[0017] The system uses a switching valve to keep the second inlet and outlet constantly open, allowing the milk frother to draw milk from the milk tank via the milk delivery tube. Before emulsification, pressurized water is supplied to the first inlet to connect the first inlet and outlet, thus filling the milk delivery tube with water. After emulsification, pressurized water can also be supplied to the first inlet to connect the first inlet and outlet, again for cleaning the milk delivery tube and the milk frother.

[0018] To simplify the structure and reduce the number of water pumps used for water delivery, the first inlet is connected to the outlet of the first water pump to deliver pressurized cold water from the first water pump to the first inlet, or the first inlet is connected to the outlet of the heater to deliver pressurized hot water from the first water pump to the first inlet. A control valve for opening and closing the inlet pipe is provided on the inlet pipe of the first inlet.

[0019] In order to accurately fill the milk delivery tube with water and meet the pressure water requirements during cleaning, such as the flow rate and velocity of the pressure water, a second water pump is connected between the water tank and the first inlet to deliver pressure water to the first inlet.

[0020] To allow switching back to milk suction mode after filling or cleaning the milk delivery tubes, a pressure relief valve is installed at the first inlet. After filling or cleaning the milk delivery tubes, the pressure is released through the pressure relief valve to the first inlet and its water supply line, causing the switching valve to reset and switch back to the normal state where the second inlet and outlet remain connected, allowing the milk froth generator to draw milk from the milk tank.

[0021] For flexible product configuration, the switching valve can be placed inside the milk tank. In this case, it is preferable that the second inlet is open at the bottom of the milk tank. Alternatively, the switching valve can be located outside the milk tank, with the second inlet connected to the bottom of the milk tank.

[0022] To facilitate connection and disconnection of the milk container from the coffee machine, the milk container is equipped with at least one of a first inlet, a second inlet, and an outlet. This connection allows for easy connection of the milk container to the coffee machine during beverage preparation, and easy removal and storage of the milk container after preparation. Residual milk can be stored in the refrigerator, and the milk container can be cleaned when empty.

[0023] To achieve switching control of milk and pressurized water using a switching valve, the switching valve includes a valve chamber, a first inlet, a second inlet, and an outlet. The valve chamber contains a valve core assembly that can move between a first position and a second position. The valve core assembly has a valve orifice, a valve plug, and a first spring. The spring force acts on the valve plug, causing it to seal the valve orifice. When the valve core assembly is in the first position due to the spring force of the second spring, it blocks the first inlet and outlet and connects the second inlet and outlet, allowing milk to flow from the second inlet. When pressurized water is introduced into the first inlet, the pressurized water overcomes the spring force of the second spring, causing the valve core assembly to move to the second position, sealing the second inlet. The pressurized water also overcomes the spring force of the first spring, pushing the valve plug open from the valve orifice, allowing the first inlet to connect to the outlet via the valve orifice, allowing pressurized water from the first inlet to flow.

[0024] Therefore, under normal conditions, since the valve core assembly is in the first position, it blocks the first inlet and outlet and connects the second inlet and outlet, allowing milk to flow from the second inlet to the outlet. When pressurized water needs to flow, pressurized water is simply supplied to the first inlet. Under the pressure of the pressurized water, the valve core assembly moves to the second position, blocking the second inlet. Furthermore, the pressurized water overcomes the spring force of the first spring, pushing the valve plug open from the valve hole, allowing the first inlet to connect to the outlet, thus enabling pressurized water to flow from the first inlet to the outlet.

[0025] To prevent milk from mixing with pressurized water, the valve core assembly is arranged in a piston shape within the valve chamber. The valve chamber is divided into a first chamber and a second chamber by the valve core assembly. The first inlet is connected to the first chamber, and when the valve core assembly is in the first position, the second inlet and outlet are connected to the second chamber. Accordingly, the valve plug assembly separates the milk from the pressurized water, allowing either the milk or the pressurized water to flow selectively to the outlet.

[0026] For ease of assembly, the valve cavity is formed by a tubular valve body and a first end cap and a second end cap that are separately connected to both ends of the tubular valve body. A sealing ring is provided between the valve core assembly and the inner wall of the tubular valve body to prevent liquid from flowing along the length of the tubular valve body at the sealing ring position. The first liquid inlet is located at the first end cap, the second liquid inlet is located at the second end cap, and the liquid outlet is located on the side wall of the tubular valve body.

[0027] In order to maintain the liquid from the first inlet at a suitable pressure, the valve core assembly includes a tubular piston seat and a support seat mounted on one end of the tubular piston seat. A second spring acts on the tubular piston seat to cause the valve core assembly to be in a first position. The valve orifice is located inside the tubular piston seat. The two ends of the first spring are supported on the valve plug and the support seat to apply a spring force to the valve plug towards the valve orifice, and the first spring maintains the liquid from the first inlet at a suitable pressure.

[0028] To simplify the flow path between the first inlet and outlet, one flow method is as follows: the tubular piston seat has a radial hole, and the outer side of the tubular piston seat has a flow gap. When the valve core assembly moves to the second position, the valve orifice communicates with the outlet through the radial hole and the flow gap. Another flow method is as follows: a flow gap is provided between the support seat and the tubular piston seat. When the valve core assembly moves to the second position, the valve orifice communicates with the outlet through the flow gap.

[0029] To reliably seal the second inlet when the valve core assembly moves to the second position, the valve plug assembly is provided with a sealing block for sealing the second inlet. In particular, an annular flange is provided at the end of the second inlet located inside the valve cavity to allow the valve core assembly to move to the second position and seal the second inlet.

[0030] In another embodiment of the invention, the filling pipeline includes a second water pump connected to a water tank and a milk delivery pipe for filling the milk delivery pipe with water stored in the water tank. In this case, a one-way valve is provided at the connection between the milk delivery pipe and the milk tank. The one-way valve controls the milk in the milk tank to flow only from the milk tank to the milk delivery pipe. The outlet end of the second water pump is connected to the outlet end of the one-way valve to prevent water delivered by the second water pump from flowing into the milk tank.

[0031] In a third embodiment of the invention, the filling pipeline includes a second water pump connected to a milk tank and a milk delivery pipe for filling the milk from the milk tank into the milk delivery pipe. In this case, a one-way valve is provided at the connection between the milk delivery pipe and the milk tank. The one-way valve controls the milk in the milk tank to flow only from the milk tank to the milk delivery pipe. The outlet end of the second water pump is connected to the outlet end of the one-way valve to prevent the milk delivered by the second water pump from flowing into the milk tank.

[0032] In order to accurately fill the milk delivery tube with water or milk, and to avoid over-delivery causing water or milk to flow out or under-delivery leaving air in the milk delivery tube, a flow meter is installed in the filling line to measure the volume of water or milk being filled into the milk delivery tube.

[0033] This invention uses a milk delivery tube connected to a filling tube to fill the milk delivery tube with water or milk before the milk frother draws milk from the milk tank.

[0034] The method of this invention involves first filling the milk delivery pipe between the milk tank and the milk frother with water or milk in the initial stage of milk emulsification to eliminate air in the delivery pipe, and then supplying steam to the milk frother. Once the steam enters the milk frother, it encounters milk or water instead of air, thereby avoiding the generation of large steam pressure in the emulsification zone at the initial stage of steam injection and shortening the existence time of steam pressure, thus avoiding or reducing the amount and intensity of milk splashing. Subsequently, the milk frother draws milk from the milk tank through the delivery pipe and emulsifies the drawn milk into milk foam, improving the user experience, avoiding the risk of burns, and keeping the coffee machine's exterior clean.

[0035] This invention uses a switching valve to control the switching between milk and pressurized water, and can also rinse the milk delivery tubes and milk frothing generator after emulsification. Furthermore, cleaning does not require disassembling the milk delivery tubes and milk frothing generator. Moreover, because the pressurized water used for cleaning is pressurized and flows entirely through the milk frothing generator and its pipelines, it can thoroughly clean the milk delivery tubes and milk frothing generator. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of the coffee machine involved in this invention;

[0037] Figure 2 This is a schematic diagram showing the flow of water during the initial emulsification stage of the system in Embodiment 1 of the present invention, when water is added to the milk delivery tube, and during the cleaning of the milk delivery tube and milk foam generator after emulsification.

[0038] Figure 3 A schematic diagram showing the flow of milk during milk foam making using the system of Embodiment 1 of the present invention;

[0039] Figure 4 This is a schematic diagram of the water flow direction during the initial filling of the milk delivery tube with water in the system of Embodiment 2 of the present invention and during the cleaning of the milk delivery tube and milk foam generator after emulsification.

[0040] Figure 5 A schematic diagram showing the flow of milk during milk foam making in the system of Embodiment 2 of the present invention;

[0041] Figure 6 This is a schematic diagram of the water flow direction during the initial emulsification of the milk delivery tube and the cleaning of the milk delivery tube and milk foam generator in the system of Embodiment 3 of the present invention.

[0042] Figure 7 A schematic diagram showing the flow direction of milk during milk foam making in the system of Embodiment 3 of the present invention;

[0043] Figure 8 This is a schematic diagram of the water flow direction during the initial emulsification of the milk delivery tube and the cleaning of the milk delivery tube and milk foam generator in the system of Embodiment 4 of the present invention.

[0044] Figure 9 A schematic diagram showing the flow of milk during milk foaming in the system of Embodiment 4 of the present invention;

[0045] Figure 10 This is a schematic diagram of the water flow direction during the initial filling of the milk delivery tube with water in the system of Embodiment 5 of the present invention and during the cleaning of the milk delivery tube and milk foam generator after emulsification.

[0046] Figure 11 A schematic diagram showing the flow of milk during milk foaming in the system of Embodiment 5 of the present invention;

[0047] Figure 12This is a cross-sectional structural diagram of the switching valve of the present invention when the second inlet and outlet are connected.

[0048] Figure 13 for Figure 12 The diagram shows an exploded view of the switching valve.

[0049] Figure 14 for Figure 12 The diagram shows a cross-sectional view of the switching valve when the first inlet and outlet are connected.

[0050] Explanation of the labels in the diagram:

[0051] 100 switching valve:

[0052] 110 Valve cavity, 111 Tubular valve body, 112 First end cap, 113 Second end cap, 114 First liquid inlet, 115 Second liquid inlet, 116 Liquid outlet, 117 Annular flange, 118 First cavity, 119 Second cavity;

[0053] 120 Valve core assembly: 121 Tubular piston seat, 122 Support seat, 123 Valve bore, 124 First spring, 125 Valve plug, 126 Sealing block, 127 Annular groove, 128 Sealing ring, 129 Radial bore;

[0054] 130mm flow gap;

[0055] 140 Second Spring;

[0056] 200 Coffee machine, 201 Water tank, 202 First water pump, 203 Heater, 204 Coffee brewing assembly, 205 Milk frother, 206 Milk container, 207 Second water pump, 208 Control valve, 209 Pressure relief valve, 210 Shut-off valve, 211 Return water box, 212 Pipe interface, 213 Safety valve, 214 Check valve, 215 Coffee outlet, 216 Flow meter, 217 Milk delivery pipe, 218 One-way valve;

[0057] 300 coffee cups. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0059] The terms “comprising” and “having”, and any variations thereof, used in the specification and claims of this invention are intended to cover a non-exclusive inclusion, such as a method or product that includes a series of technical features, not necessarily limited to those technical features explicitly listed, but may also include other technical features that may be included in the method or product but not explicitly listed.

[0060] In the description of this invention, it should be understood that the technical features defined by terms such as "first" and "second" which have a sequential concept are only used to clearly describe the defined technical features and to clearly distinguish the defined technical features from other technical features, and do not represent that they are named in this way in actual implementation. Therefore, they should not be construed as limitations on this invention.

[0061] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0062] like Figure 12-14 The diagram shows a switching valve for a milk frothing system. The switching valve includes a valve chamber 110 and a valve core assembly 120 disposed within the valve chamber.

[0063] The valve cavity 110 is formed by a tubular valve body 111 and a first end cap 112 and a second end cap 113 separately connected to both ends of the tubular valve body. The first end cap 112 and the second end cap 113 are preferably connected to both ends of the tubular valve body by threads. The valve cavity 110 has a first inlet 114, a second inlet 115, and an outlet 116. The first inlet 114 is located on the first end cap 112. The second inlet 115 is located on the second end cap 113. An annular flange 117 is provided at one end of the second inlet 115 within the valve cavity to seal the second inlet when the valve core assembly moves to the second position. The outlet 116 is located at the lower end of the side wall of the tubular valve body 111, near the second end cap.

[0064] The valve core assembly 120 is arranged in a piston shape within the valve chamber 110 and can move between a first position and a second position. The valve core assembly 120 includes a tubular piston seat 121, a support seat 122, a valve hole 123, a first spring 124, a valve plug 125, and a sealing block 126. The valve hole 123 is located at the center of the tubular piston seat 121 and opens into the first chamber 118. The support seat 122 is threaded onto the lower end of the tubular piston seat 121. The first spring 124 and the valve plug 125 are located between the lower side of the valve hole 123 and the support seat 122, and the two ends of the first spring 124 are supported on the valve plug 125 and the support seat 122, applying a spring force towards the valve hole to the valve plug. When there is no pressurized water at the first inlet, the spring force of the first spring 124 causes the valve plug 125 to seal the valve hole 123. A sealing block 126 is embedded in the lower end of the support base 122 and corresponds to the second liquid inlet 115 to block the second liquid inlet when the valve core assembly is in the second position. The outer wall of the tubular piston seat 121 is provided with an annular groove 127, and a sealing ring 128 is fitted inside the annular groove 127. The sealing ring 128 is squeezed against the inner wall of the tubular valve body 111 and within the annular groove 127 to achieve a seal, preventing liquid from flowing along the length of the tubular valve body at the sealing ring position. Furthermore, the valve core assembly 120 is located... Figure 12 In the first position shown, valve chamber 110 is isolated into a first chamber 118 and a second chamber 119 by valve core assembly 120. The first inlet 114 connects to the first chamber 118. When valve core assembly 120 is in the second position, the second inlet 115 and outlet 116 connect to the second chamber 119. Furthermore, the outer diameter of the tubular piston seat 121 is smaller than the inner diameter of the tubular valve body 111, and a flow gap 130 is maintained between the tubular piston seat 121 and the inner wall of the tubular valve body 111. The tubular piston seat 121 is provided with a radial hole 129. The valve core assembly 120 moves to... Figure 14 In the second position shown, the valve orifice 123 communicates with the outlet 116 via the radial hole 129 and the flow gap 130. In other embodiments, a flow gap is provided between the support base 122 and the tubular piston seat 121, and when the valve core assembly moves to the second position, the valve orifice communicates with the outlet via the flow gap.

[0065] The second spring 140 is sleeved on the outside of the tubular piston seat 121, and its two ends are respectively supported on the tubular piston seat 121 and the tubular valve body 111. The second spring 140 applies an upward elastic force to the tubular piston seat 121, causing the valve core assembly 120 to be positioned when there is no pressurized water in the first cavity. Figure 12 The first position is shown.

[0066] Therefore, under normal conditions, valve core assembly 120, as Figure 12 As shown in the first position, the first inlet 114 and outlet 116 are blocked, while the second inlet 115 and outlet 116 are connected to allow milk to flow from the second inlet. Figure 12When pressurized water is input into the first inlet 114 as shown, the pressurized water overcomes the elastic force of the second spring 140, causing the valve core assembly 120 to move and change position. Figure 14 The second position shown blocks the second inlet 115, and the pressurized water also overcomes the elastic force of the first spring 124 to push the valve plug 125 open from the valve hole 123, allowing the first inlet 114 to connect to the outlet 116 through the valve hole 123, the radial hole 129, and the flow gap 130, so that pressurized water from the first inlet can flow. Figure 12 and Figure 14 The direction of liquid flow is indicated by a dashed line with an arrow.

[0067] The aforementioned switching valve is used in the milk frothing method and system of a coffee machine, and can switch the delivery of milk and pressurized water.

[0068] like Figure 1 The coffee machine shown typically places the milk pitcher in a location that allows for easy connection and disconnection from the coffee machine.

[0069] Example 1

[0070] like Figure 2-3 The diagram shows the water and milk circuit configuration of the coffee machine in this embodiment, including a milk frothing system. The milk frothing system includes a water tank 201, a first water pump 202, a second water pump 207, a heater 203, a milk frother 205, a milk delivery pipe 217, a milk container 206, and a switching valve 100. Water in the water tank 201 is pumped by the first water pump 202 to the heater 203, where it is vaporized and then supplied to the milk frother 205. The milk container 206 is connected to the milk frother 205 via the milk delivery pipe 217, allowing the milk frother to draw milk from the container and emulsify it. The second water pump 207 connects the water tank 201 to the first liquid inlet 114, supplying pressurized water to the first liquid inlet 114; that is, the water in the tank is pressurized by the pump to a higher pressure. A pressure relief valve 209 is provided for the first liquid inlet 114. This pressure relief valve 209 is a two-position two-way solenoid valve, with one position closed and the other position open. A switching valve 100 is located inside the milk tank 206, and the second liquid inlet 114 is open at the bottom of the milk tank 206. The milk tank 206 is provided with pipe interfaces 212 for the first liquid inlet and outlet. The second water pump 207, the switching valve 100, and their associated pipes constitute the filling pipeline.

[0071] exist Figure 2-3In this system, a safety valve 213 is connected to the outlet pipe of the first water pump 202. The outlet of the heater 203 is connected to the coffee brewing assembly 204 via a pipe, and a check valve 214 is installed in this pipe. A shut-off valve 210 is installed on the pipe between the outlet of the heater 203 and the milk frother 205. This shut-off valve 210 is a two-position two-way solenoid valve, with one position of the two-position two-way solenoid valve in the closed state and the other position in the open state.

[0072] According to the above Figure 2-3 As shown in the structure, the first inlet 114 of the switching valve 100 is used to input pressurized water, the second inlet 115 of the switching valve is used to draw milk from the milk tank, and the outlet 116 is connected to the milk frother. Furthermore, the first inlet 114 and the second inlet 115 of the switching valve 100 are selectively connected to the outlet 116 to allow pressurized water or milk to flow out from the outlet. The second inlet 114 and the outlet 116 are normally open to allow the milk frother to draw milk from the milk tank. When pressurized water is supplied to the first inlet 114, the valve switches to connect the first inlet 114 to the outlet 116 to clean the outlet 116, the subsequent piping, and the milk frother.

[0073] According to the above Figure 2-3 As shown in the diagram, when making coffee, the shut-off valve 210 is closed, and water in the water tank 201 is pumped by the first water pump 202 to the coffee brewing assembly 204. The water is heated by the heater 203 to become hot water. The hot water flows through the coffee brewing assembly at a certain temperature and pressure, extracting the coffee powder into a coffee beverage. The coffee beverage flows out of the coffee brewing assembly and into the coffee cup 300 from the coffee outlet 215. The first water pump 202 stops operating when the water delivery reaches the set value, as measured by the flow meter 216.

[0074] When adding milk foam to a coffee beverage, first... Figure 2 As shown, the first water pump is stopped, and the second water pump 207 is started to fill the milk delivery pipe 217 with water. The water flow rate is measured by the flow meter 216. The milk delivery pipe 217 is filled with water, and the switching valve 100 is in the position during this process. Figure 14 The first liquid inlet 114 is connected to the liquid outlet 116 as shown. Figure 2 The direction of water flow is indicated by a dotted line marked with an arrow. After water is added to the milk delivery tube 217, the second water pump 207 is immediately stopped, the pressure relief valve 209 is opened, and the water stored in the first chamber 118 is discharged to the return water box 211 through the pressure relief valve 209 under the action of the second spring 140. The switching valve 100 is then reset to its original position. Figure 12 The state shown. Then as... Figure 3As shown, when the shut-off valve 210 is opened, the first water pump 202 and the heater 203 are started. Water is vaporized by the heater and flows through the shut-off valve 210 to the milk frother 205. The high-speed flow of steam in the milk frother creates negative pressure, which is then released through the milk delivery pipe 217 and... Figure 12 The second inlet 115 and outlet 116, as shown, draw milk from the milk tank 206 into the milk frother 205. The milk is emulsified into milk foam in the milk frother and then flows out to be added to the coffee beverage. The milk foam flowing from the milk frother can be poured directly into the coffee cup or added to the coffee cup using a tool. Figure 3 The direction of milk flow is indicated by dashed lines marked with arrows.

[0075] After the milk foam is prepared, clean the milk ducts: such as Figure 2 As shown, the first water pump 202 and heater 203 stop working, the shut-off valve 210 is closed, the pressure relief valve 209 is closed, the second water pump 207 is started, and the switching valve 100 is in the [position missing]. Figure 14 As shown, with the first inlet 114 and outlet 116 connected, water in the water tank 201 is pumped by the second pump 207 to the first inlet 114, then flows through the switching valve 100, the milk delivery pipe 217, and the milk frother 205, finally exiting from the milk frother, thus rinsing the milk frother and milk path. The rinsing process can be controlled by setting a time or flow rate; rinsing stops after the rinsing time or flow rate is reached. Figure 2 The direction of pressurized water flow is indicated by a dashed line marked with an arrow.

[0076] After rinsing is completed, the second water pump 207 is stopped, the pressure relief valve 209 is opened, and the water stored in the first chamber 118 is discharged to the return water box 211 through the pressure relief valve 209 under the action of the second spring 140. The switching valve 100 is then reset to its original position. Figure 12 The state shown.

[0077] Example 2

[0078] like Figure 4-5As shown, the difference between this embodiment and Embodiment 1 is that only a first water pump 202 is provided, and the second water pump is omitted. In this embodiment, the first inlet 114 is connected to the outlet of the heater 203 to supply pressurized hot water from the first water pump to the first inlet 114. A control valve 208 for opening and closing the inlet pipe of the first inlet 114 is provided. The control valve is a two-position three-way solenoid valve, which also functions as a pressure relief valve. One position of the two-position three-way solenoid valve is used for pressure relief, that is, connecting the first cavity and the return water box, at which time the pipe between the first inlet 114 and the heater 203 is closed. The other position of the two-position three-way solenoid valve is used to connect the first cavity and the outlet of the heater 203, at which time the pressure relief function is closed. The rest of the structure is the same as in Embodiment 1, and the same parts will not be described again. Among them, the first water pump 206, the control valve 208, the switching valve 100 and the pipes they are connected to constitute the filling pipeline.

[0079] According to the above Figure 4-5 As shown in the diagram, when making coffee, the shut-off valve 210 is closed, and the control valve 208 is closed (pressure relief function is activated). Water in the water tank 201 is pumped by the first water pump 202 to the coffee brewing assembly 204. The water is heated by the heater 203 to become hot water. The hot water flows through the coffee brewing assembly 204 at a certain temperature and pressure, extracting the coffee powder into a coffee beverage. The coffee beverage flows out of the coffee brewing assembly and into the coffee cup 300 from the coffee outlet 215. The first water pump and heater stop operating when the water delivery volume reaches the set value, as measured by the flow meter 216.

[0080] When adding milk foam to a coffee beverage, first... Figure 4 As shown, when control valve 208 is opened, the first water pump 202 is started to supply water to the first inlet 114, and the switching valve is switched to... Figure 14 As shown, the first inlet 114 is connected to the outlet 116. The milk delivery tube 217 is filled with water, and the water flow is measured by the flow meter 216 until the milk delivery tube 217 is filled with water. Figure 4 The direction of water flow is indicated by a dashed line marked with an arrow. After water is added to the milk delivery tube 217, the first water pump 202 is stopped, the control valve 208 is closed (the pressure relief function is activated), and the water stored in the first chamber 118 is discharged to the return water box 211 through the control valve 208 under the action of the second spring 140. The switching valve 100 is then reset to its original position. Figure 12 The second inlet 115 is shown connected to the outlet 116. For example... Figure 5As shown, opening the shut-off valve 210 starts the first water pump 202 and the heater 203. Water is vaporized by the heater and flows through the shut-off valve 210 to the milk frother 205. The high-speed flow of steam in the milk frother creates negative pressure, drawing milk from the milk tank into the milk frother 205 through the milk delivery pipe 217 and the connected first inlet 114 and outlet 116. The milk is emulsified into milk foam in the milk frother and then flows out of the milk frother for addition to coffee beverages. The milk foam flowing out of the milk frother can flow directly into the coffee cup or be added to the coffee cup with the help of a tool. Figure 5 The direction of milk flow is indicated by dashed lines marked with arrows.

[0081] After the milk foam is prepared, clean the milk ducts: such as Figure 4 As shown, when the shut-off valve 210 is closed and the control valve 208 is opened (de-pressurization function is off), the first water pump 202 and heater 203 operate. Water in the water tank 201 is pumped by the first water pump 202 to the first inlet 114 via the control valve 208. The switching valve 100 is in the [position missing]. Figure 14 As shown, water is heated by heater 203, then flows through switching valve 100, milk delivery pipe 217, and milk froth generator 205, finally exiting from the milk froth generator to flush the milk froth generator and milk path. The flushing process can be controlled by setting a time or flow rate, and flushing stops after the flushing time or flow rate is reached. Figure 4 The direction of pressurized water flow is indicated by a dashed line marked with an arrow.

[0082] After rinsing, the pressure relief function of control valve 208 is activated. Water stored in the first chamber 118 is released through control valve 208 to the return water box 211 under the action of the second spring 140. Switching valve 100 then resets to its original position. Figure 12 The state shown.

[0083] In this embodiment, a better cleaning effect can be achieved by rinsing with hot water.

[0084] Based on this embodiment, the first inlet 114 can also be connected to the outlet of the first water pump before the heater, so that the first water pump can deliver pressurized cold water to the first inlet 114.

[0085] Example 3

[0086] like Figure 6-7 As shown, the difference between this embodiment and Embodiment 2 is that the switching valve 100 is located outside the milk tank 206, and the second inlet 114 is connected to the bottom of the milk tank 206 for drawing milk from the milk frother 205. The remaining structure is the same as in Embodiment 1, and the identical parts will not be described again. The processes for making coffee, making milk froth, and cleaning are all the same as in Embodiment 2. Figure 6The dashed lines marked with arrows indicate the direction of water flow when filling the milk delivery tubes and cleaning the milk delivery tubes and milk frothing generator. Figure 7 The direction of milk flow is indicated by dashed lines marked with arrows.

[0087] Example 4

[0088] like Figure 8-9 As shown, the difference between this embodiment and Embodiment 1 is that the switching valve 100 and the pressure relief valve 209 are omitted. The second water pump 207 is connected to the water tank and the milk delivery pipe to fill the milk delivery pipe with water stored in the water tank. A one-way valve 218 is provided at the connection between the milk delivery pipe and the milk tank. The one-way valve 218 controls the milk in the milk tank to flow only from the milk tank to the milk delivery pipe. The outlet end of the second water pump is connected to the outlet end of the one-way valve to prevent the water delivered by the second water pump from flowing into the milk tank. The rest of the structure is the same as in Embodiment 1 and will not be described in detail. The pipeline where the second water pump 207 is located constitutes the filling pipeline.

[0089] According to the above Figure 8-9 As shown in the diagram, when making coffee, the shut-off valve 210 is closed, and water in the water tank 201 is pumped by the first water pump 202 to the coffee brewing assembly 204. The water is heated by the heater 203 to become hot water. The hot water flows through the coffee brewing assembly at a certain temperature and pressure, extracting the coffee powder into a coffee beverage. The coffee beverage flows out of the coffee brewing assembly and into the coffee cup 300 from the coffee outlet 215. The first water pump 202 stops operating when the water delivery reaches the set value, as measured by the flow meter 216.

[0090] When adding milk foam to a coffee beverage, first... Figure 8 As shown, the first water pump is stopped, and the second water pump 207 is started to fill the milk delivery pipe 217 with water. The water volume is measured by the flow meter 216, and the milk delivery pipe 217 is filled with water. Figure 8 The direction of water flow is indicated by a dashed line marked with an arrow. After water is added to milk inlet tube 217, the flow continues as follows... Figure 9 As shown, the second water pump 207 is stopped, the shut-off valve 210 is opened, and the first water pump 202 and heater 203 are started. Water is vaporized by the heater and flows through the shut-off valve 210 to the milk frother 205. The high-speed flow of steam in the milk frother creates negative pressure, drawing milk from the milk tank 206 into the milk frother 205 through the milk delivery pipe 217. The milk is emulsified into milk foam in the milk frother and then flows out of the milk frother for addition to coffee beverages. The milk foam flowing out of the milk frother can flow directly into the coffee cup or be added to the coffee cup with the help of a tool. Figure 9 The direction of milk flow is indicated by dashed lines marked with arrows.

[0091] After the milk foam is prepared, clean the milk ducts: such as Figure 8As shown, the first water pump 202 and heater 203 stop working, the shut-off valve 210 is closed, and the second water pump 207 is started. The water in the water tank 201 is transported by the second water pump 207 to the milk delivery pipe 217 and the milk frothing generator 205, and finally discharged from the milk frothing generator, thus rinsing the milk frothing generator and the milk passage. The rinsing process can be controlled by setting a time or flow rate, and rinsing stops after the rinsing time or flow rate is reached. Figure 8 The direction of pressurized water flow is indicated by a dashed line marked with an arrow.

[0092] Example 5

[0093] like Figure 10-11 As shown, the difference between this embodiment and embodiment 4 is that the second water pump 207 is connected to the milk tank 206 and the milk delivery pipe 217 to fill the milk from the milk tank into the milk delivery pipe. To accurately measure the milk delivery volume of the second water pump, a flow meter is installed in the pipeline where the second water pump is located. A one-way valve 218 is installed at the connection between the milk delivery pipe 217 and the milk tank 206. The one-way valve 218 controls the milk in the milk tank to flow only from the milk tank to the milk delivery pipe. The outlet end of the second water pump is connected to the outlet end of the one-way valve to prevent the milk delivered by the second water pump from flowing into the milk tank. The remaining structure is the same as in embodiment 4 and will not be described in detail. The pipeline containing the second water pump 207 and the flow meter in that pipeline constitute the filling pipeline.

[0094] The coffee-making and milk-foaming processes in this embodiment are the same as in Embodiment 4. However, milk, not water, is used to fill the milk delivery tube during the initial emulsification stage. Figure 10 The dashed line marked with an arrow indicates the direction of milk flow when filling the milk tube. Figure 11 The dashed line with arrows indicates the direction of milk flow when making milk foam.

[0095] In this embodiment, when cleaning the milk delivery tube and milk frothing generator 205, clean water is added to the milk tank, and the second water pump is started to deliver the water in the milk tank to the milk delivery tube and milk frothing generator, just like filling the milk delivery tube with water, and the water flows out from the milk frothing generator to achieve cleaning.

[0096] In the aforementioned embodiments, the milk container is provided with at least one of the following pipe interfaces: a first liquid inlet 114, a second liquid inlet 115, and a liquid outlet 116, for connecting or separating the milk container from the coffee machine.

[0097] Among them, the first and second water pumps are preferably plunger pumps. When the plunger pump is working, it transports liquid. When the plunger pump stops working, it can block the pipeline where it is located and prevent the liquid from flowing in the pipeline where the plunger pump is located.

Claims

1. The method of making milk froth in a coffee machine, implemented through a milk frothing system, is characterized by: The milk foam making system includes a milk foam generator (205), which is connected to a milk tank (206) via a milk delivery pipe. The milk delivery pipe is connected to a filling pipe for filling the milk delivery pipe with water or milk before the milk foam generator (205) draws milk from the milk tank. The method includes the following steps: (1) At the beginning stage of emulsifying milk, water or milk is first added to the milk delivery tube between the milk tank and the milk foam generator to eliminate the air in the milk delivery tube; (2) Steam is then supplied to the milk frother. The steam enters the milk frother and encounters milk or water instead of air, thus avoiding the generation of large steam pressure in the emulsification zone at the beginning of steam injection, shortening the existence time of steam pressure, avoiding splashing milk or reducing the amount and intensity of splashing milk. Subsequently, the high-speed flow of steam in the milk frother forms negative pressure, and the milk frother draws milk from the milk tank through the milk delivery tube and emulsifies the milk into milk foam, thus avoiding the risk of scalding.

2. The method for making milk foam in a coffee machine according to claim 1, characterized in that: Steam is pumped to the milk frother by the first water pump, and water or milk is pumped into the milk delivery tube by the second water pump.

3. The method for making milk foam in a coffee machine according to claim 2, characterized in that: The second water pump connects the water tank and the milk delivery pipe to pump water from the water tank into the milk delivery pipe.

4. The method for making milk foam in a coffee machine according to claim 3, characterized in that: A one-way valve is installed at the connection between the milk delivery pipe and the milk tank. The one-way valve controls the milk in the milk tank to flow only from the milk tank to the milk delivery pipe. The outlet end of the second water pump is connected to the outlet end of the one-way valve to prevent the water delivered by the second water pump from flowing into the milk tank.

5. The method for making milk foam in a coffee machine according to claim 2, characterized in that: The second pump connects the milk tank and the milk delivery pipe to pump milk from the milk tank into the milk delivery pipe.

6. The method for making milk foam in a coffee machine according to claim 5, characterized in that: A one-way valve is installed at the connection between the milk delivery tube and the milk tank. The one-way valve controls the milk in the milk tank to flow only from the milk tank to the milk delivery tube. The outlet end of the second water pump is connected to the outlet end of the one-way valve to prevent the milk delivered by the second water pump from flowing into the milk tank.

7. The method for making milk foam in a coffee machine according to claim 1, characterized in that: The first water pump first fills the milk delivery pipe with water and then delivers steam to the milk frothing generator.

8. The method for making milk foam in a coffee machine according to claim 1, characterized in that: The method includes the following steps: (3) After emulsification, water is automatically supplied to rinse the milk delivery tube and milk foam generator.

9. The method for making milk foam in a coffee machine according to any one of claims 1-8, characterized in that: Stop step (1) when the milk infusion tube is filled with water or milk, and start step (2).

10. A system for implementing the milk foam making method according to any one of claims 1-9, characterized in that: It includes a water tank (201), a first water pump (202), a heater (203), and a milk frother (205) connected sequentially according to the direction of water flow.

11. The system according to claim 10, characterized in that: The filling pipeline includes a switching valve (100), which includes a first inlet (114), a second inlet (115), and an outlet (116). The first inlet (114) is used to input pressurized water, the second inlet (115) is used to draw milk from the milk tank, and the outlet (116) is connected to the milk delivery pipe. The switching valve is configured such that the first inlet (114) and the second inlet (115) are selectively connected to the outlet (116) to allow pressurized water or milk to flow out from the outlet. The second inlet (115) and the outlet (116) are kept open to allow the milk frother to draw milk from the milk tank through the milk delivery pipe. When pressurized water is supplied to the first inlet (114), the valve switches to connect the first inlet (114) and the outlet (116) to fill the milk delivery pipe with water or to clean the milk delivery pipe and the milk frother.

12. The system according to claim 11, characterized in that: The first inlet (114) is connected to the outlet of the first water pump (202) for supplying pressurized cold water to the first inlet (114) by the first water pump, or the first inlet (114) is connected to the outlet of the heater (203) for supplying pressurized hot water to the first inlet (114) by the first water pump. The inlet pipe of the first inlet (114) is provided with a control valve (208) for opening and closing the inlet pipe.

13. The system according to claim 11, characterized in that: A second water pump (207) is connected between the water tank (201) and the first liquid inlet (114) to deliver pressurized water to the first liquid inlet (114).

14. The system of claim 10, characterized in that: The filling pipeline includes a second water pump, which connects the water tank and the milk delivery pipe to fill the milk delivery pipe with water stored in the water tank.

15. The system according to claim 14, characterized in that: A one-way valve is installed at the connection between the milk delivery pipe and the milk tank. The one-way valve controls the milk in the milk tank to flow only from the milk tank to the milk delivery pipe. The outlet end of the second water pump is connected to the outlet end of the one-way valve to prevent the water delivered by the second water pump from flowing into the milk tank.

16. The system of claim 10, characterized in that: The filling pipeline includes a second water pump, which connects the milk tank and the milk delivery pipe to fill the milk tank into the milk delivery pipe.

17. The system according to claim 16, characterized in that: A one-way valve is installed at the connection between the milk delivery tube and the milk tank. The one-way valve controls the milk in the milk tank to flow only from the milk tank to the milk delivery tube. The outlet end of the second water pump is connected to the outlet end of the one-way valve to prevent the milk delivered by the second water pump from flowing into the milk tank.

18. The system according to any one of claims 10 and 14-17, characterized in that: A flow meter is installed in the filling pipeline to measure the volume of water or milk being filled into the milk delivery pipe.

Images