Coffee machine milk path cleaning system, pressure release valve and coffee machine working method

Abstract

The invention discloses a coffee machine milk path cleaning system, a pressure release valve and a coffee machine working method, belongs to the coffee machine technology, and aims to solve the problems of high cost, large size and difficulty in layout of a milk path cleaning system of an existing coffee machine which adopts an electromagnetic valve to release pressure. The pressure relief valve is provided with a water passing channel, a pressure relief opening, an actuating opening and a valve element, the second water pump is used for conveying stored water in the water tank to the first liquid inlet of the switching valve through the water passing channel, and the valve element moves by means of the elastic force of the elastic element or the pressure of water from the actuating opening to switch the pressure relief opening and the water passing channel to be communicated or closed. The pressure relief valve is a mechanical valve, does not need electric control, is small in size and low in cost, can be matched with the elastic element to promote the valve element to move to switch the circulation and closing of the pressure relief opening and the water passing channel only by connecting the water pipe between the first water pump and the pressure relief valve, and is easy to deform and bend, easy to arrange in the coffee machine and small in occupied space.

Description

Technical Field

[0001] The invention belongs to the coffee machine technology, and in particular relates to a coffee machine milk circuit cleaning system, a pressure relief valve and a coffee machine working method. Background Art

[0002] The patent document with application publication number CN116649786A discloses a milk line cleaning system for a coffee machine. After flushing is completed, the pressure relief valve is opened to relieve the pressure of the pressurized water delivered to the first liquid inlet of the switching valve, so as to reset the switching valve and switch the working state. The pressure relief valve described in the patent document is a solenoid valve, which is large in size and high in cost, and is not easy to arrange in a coffee machine with a given shape. Moreover, the circuit control part needs to be configured to control the solenoid valve, which may cause the increase of the circuit board and the wiring burden of the power cord, and also make the internal structure difficult to arrange. Summary of the invention

[0003] The technical problem to be solved and the technical task proposed by the present invention are to overcome the defects of the existing coffee machine milk circuit cleaning system caused by the solenoid valve pressure relief, such as high cost, large size and difficulty in layout of the internal structure, and to provide a coffee machine milk circuit cleaning system, a pressure relief valve and a coffee machine working method.

[0004] To achieve the above-mentioned object, the coffee machine milk circuit cleaning system of the present invention comprises a water tank, a first water pump, a heater, an emulsifier, a milk tank and a switching valve;

[0005] The first water pump is used to transport the water stored in the water tank to the heater, the heater is used to vaporize the water into steam and transport the steam to the emulsifier, the milk tank is connected to the emulsifier so that the emulsifier draws milk from the milk tank and emulsifies the milk;

[0006] The switching valve comprises a first liquid inlet, a second liquid inlet and a liquid outlet, the first liquid inlet is used to input pressurized water, the second liquid inlet is used to suck milk from a milk tank, and the liquid outlet is connected to an emulsifier; the switching valve is configured so that the first liquid inlet and the second liquid inlet are selectively connected to the liquid outlet so that pressurized water or milk flows out of the liquid outlet; the second liquid inlet and the liquid outlet are kept in normal communication for the emulsifier to suck milk from the milk tank, and when pressurized water is delivered to the first liquid inlet of the switching valve, the first liquid inlet is switched to be connected to the liquid outlet so as to clean the liquid outlet and the pipeline and the emulsifier thereafter;

[0007] Its characteristics are: a cleaning pressure relief pipeline is configured, the cleaning pressure relief pipeline includes a second water pump and a pressure relief valve, the pressure relief valve includes a water passage, a pressure relief port, an actuating port and a valve core, the second water pump is used to transport the water stored in the water tank to the first liquid inlet of the switching valve through the water channel, the actuating port is connected to the first water pump, and the valve core switches the flow and closure of the pressure relief port and the water passage by the elastic force of the elastic element or the pressure of the water from the actuating port.

[0008] Accordingly, the cleaning and pressure relief pipeline is used to clean the milk circuit and relieve the pressure of the pressurized water. In addition, the valve core switches the flow and closure of the pressure relief port and the water passage by the elastic force of the elastic element or the pressure of the water from the actuating port. When the pressure relief port and the water passage are closed, they are used to clean the milk circuit, and when the pressure relief port and the water passage are in communication, they are used to relieve the pressure of the pressurized water.

[0009] The pressure relief valve is a mechanical valve, which does not require electrical control, is small in size and low in cost. Moreover, it is only necessary to connect a water pipe between the first water pump and the pressure relief valve to cooperate with the elastic element to cause the valve core to move to switch the flow and closure of the pressure relief port and the water passage. The water pipe is easy to deform and bend, and is easy to lay out inside the coffee machine, occupying a small space.

[0010] In one embodiment, the pressure relief valve is embodied as a structure in which the pressure relief port is normally closed, the valve core uses the elastic force of the elastic element to keep the pressure relief port and the water passage closed, and the valve core moves by the pressure of water from the actuating port to allow the pressure relief port and the water passage to flow. Specifically, the pressure relief valve includes a valve body, the water passage runs through the valve body, an inner cavity connected to the water passage is provided in the valve body, the pressure relief port is located on one side of the water passage and communicates with the inner cavity, the valve core is located in the inner cavity of the valve body, the valve core includes a first sealing ring, a second sealing ring is located in a connecting groove between the first sealing ring and the second sealing ring, the first sealing ring and the second sealing ring are separated on both sides of the pressure relief port to close the pressure relief port and the water passage, the first sealing ring or the second sealing ring is staggered from the pressure relief port and the pressure relief port is connected with the water passage by the connecting groove. In this way, the pressure relief valve is kept compact and small in size.

[0011] In another embodiment, the pressure relief valve is embodied as a structure in which the pressure relief port is normally open, the valve core uses the elastic force of the elastic element to keep the pressure relief port and the water passage flowing, and the valve core moves by the pressure of water from the actuating port to close the pressure relief port and the water passage. Specifically, the pressure relief valve includes a valve body, the water passage runs through the valve body, the valve body is provided with an inner cavity connected to the water passage and a valve port, the pressure relief port is located on one side of the water passage and connected to the inner cavity, the valve core is located in the inner cavity of the valve body, the valve core leaves the valve port to keep the pressure relief port and the water passage flowing, and the valve core blocks the valve port to close the pressure relief port and the water passage. In this way, the pressure relief valve is kept compact and small in size.

[0012] Preferably, the first water pump and the second water pump are plunger pumps for providing stable water pressure.

[0013] Preferably, the pressure of water delivered by the first water pump is greater than the pressure of water delivered by the second water pump. The water pump model is selected according to the needs to save manufacturing costs.

[0014] Preferably, the outlet end of the first water pump is connected to a safety valve to release pressure when the water delivery pressure of the first water pump is relatively high, so as to keep the pressure of the water delivered by the first water pump to the downstream stable.

[0015] Preferably, the heater is connected to the check valve and the coffee brewing assembly; the pipeline between the heater and the check valve is connected to the emulsifier via the steam pipeline, and the steam pipeline is provided with a first stop valve for controlling the circulation and closing of the steam pipeline; the pipeline between the heater and the check valve is also connected to the pipeline between the first water pump and the water tank via the return pipeline, and the return pipeline is provided with a second stop valve for controlling the circulation and closing of the return pipeline. Accordingly, the water flow can be circulated in the first water pump and the heater as needed during the startup or operation of the coffee machine. When the first water pump is started for the first time after startup, the cycle is started, and the pressure at the outlet end of the first water pump is small, which is conducive to the startup of the first water pump. During the operation, since the water temperature required for brewing coffee is lower than the temperature of the steam when emulsifying milk, when emulsifying milk first and then brewing coffee, the heater is easy to heat the delivered cold water to overheat due to maintaining a high temperature, which is not conducive to brewing coffee. After starting the cycle, the circulating water flow can cool the heater to ensure that the temperature of the hot water output by the heater is consistent when brewing coffee.

[0016] To achieve the above purpose, the pressure relief valve of the present invention includes a water passage, a pressure relief port, an actuating port and a valve core. The valve core moves by the elastic force of an elastic element or the pressure of water from the actuating port to switch the flow and closure of the pressure relief port and the water passage.

[0017] In one embodiment, the pressure relief valve is embodied as a structure in which the pressure relief port is normally closed, the valve core uses the elastic force of the elastic element to keep the pressure relief port and the water passage closed, and the valve core moves by the pressure of water from the actuating port to allow the pressure relief port and the water passage to flow. Specifically, the pressure relief valve includes a valve body, the water passage runs through the valve body, an inner cavity connected to the water passage is provided in the valve body, the pressure relief port is located on one side of the water passage and communicates with the inner cavity, the valve core is located in the inner cavity of the valve body, the valve core includes a first sealing ring, a second sealing ring is located in a connecting groove between the first sealing ring and the second sealing ring, the first sealing ring and the second sealing ring are separated on both sides of the pressure relief port to close the pressure relief port and the water passage, the first sealing ring or the second sealing ring is staggered from the pressure relief port and the pressure relief port is connected with the water passage by the connecting groove. In this way, the pressure relief valve is kept compact and small in size.

[0018] In one embodiment, the pressure relief valve is embodied as a structure in which the pressure relief port is normally open, the valve core uses the elastic force of the elastic element to keep the pressure relief port and the water passage flowing, and the valve core moves by the pressure of water from the actuating port to close the pressure relief port and the water passage. Specifically, the pressure relief valve includes a valve body, the water passage runs through the valve body, the valve body is provided with an inner cavity connected to the water passage and a valve port, the pressure relief port is located on one side of the water passage and connected to the inner cavity, the valve core is located in the inner cavity of the valve body, the valve core leaves the valve port to keep the pressure relief port and the water passage flowing, and the valve core blocks the valve port to close the pressure relief port and the water passage. In this way, the pressure relief valve is kept compact and small in size.

[0019] To achieve the above object, the coffee machine working method of the present invention comprises the following steps:

[0020] (1) Emulsifying milk: The first water pump transports the water in the water tank to the heater, and the heater vaporizes the water into steam and transports the steam to the emulsifier. The emulsifier draws milk from the milk tank through the second liquid inlet and liquid outlet of the switching valve by the flow of steam and emulsifies the milk.

[0021] (2) Cleaning the milk circuit: The second water pump delivers the water stored in the water tank to the first liquid inlet of the switching valve through the water passage of the pressure relief valve. The switching valve switches to connect the first liquid inlet with the liquid outlet to clean the liquid outlet and the subsequent pipelines and emulsifier.

[0022] (3) Pressure relief: The valve core of the pressure relief valve is moved to allow the pressure relief port of the pressure relief valve to flow with the water passage to relieve pressure.

[0023] The method controls the state of the pressure relief valve through the first water pump to relieve pressure as needed, so that the switching valve is reset and the working state is changed.

[0024] In one embodiment, when executing step (2), the first water pump stops working, and the valve core of the pressure relief valve keeps the pressure relief port and the water passage closed by the elastic force of the elastic element; when executing step (3), the first water pump is started to supply water to the actuating port of the pressure relief valve, and the valve core moves by the pressure of the water from the actuating port to cause the pressure relief port and the water passage to flow.

[0025] In another embodiment, when executing step (2), the first water pump is started to deliver water to the actuating port of the pressure relief valve, and the valve core keeps the pressure relief port and the water passage closed by the water pressure from the actuating port;

[0026] When executing step (3), the first water pump stops working, and the valve core of the pressure relief valve moves by the elastic force of the elastic element to promote the flow of the pressure relief port and the water passage.

[0027] Preferably, the coffee machine working method comprises the following steps:

[0028] (a) The first water pump delivers the stored water from the water tank to the heater and returns the water to the first water pump through the return pipe;

[0029] (b) Close the return water pipe;

[0030] (c) The first water pump delivers water to the heater, and the heater heats the water into hot water, and the hot water flows to the coffee brewing component for brewing coffee; or, the first water pump delivers water to the heater, and the heater heats the water into steam, and the steam flows to the emulsifier for the emulsifier to draw milk from the milk tank and emulsify the milk.

[0031] When the first water pump is started for the first time after startup, the cycle is started, and the pressure at the outlet of the first water pump is small, which is conducive to starting the first water pump.

[0032] Preferably, the coffee machine working method comprises the following steps:

[0033] (A) A first water pump delivers water to a heater, the heater heats the water into steam, and the steam flows to an emulsifier for the emulsifier to draw milk from a milk tank and emulsify the milk;

[0034] (B) the first water pump delivers the stored water from the water tank to the heater, and the water flows back to the first water pump through the return pipe;

[0035] (C) The water return line is closed, and the first water pump delivers water to the heater. The heater heats the water into hot water, and the hot water flows to the coffee brewing component for brewing coffee.

[0036] During operation, since the water temperature required for brewing coffee is lower than the temperature of the steam when emulsifying milk, when emulsifying milk first and then brewing coffee, the heater will easily overheat the delivered cold water due to its high temperature, which is not conducive to brewing coffee. After turning on this cycle, the circulating water flow can cool the heater to ensure that the hot water output by the heater is at a consistent temperature when brewing coffee.

[0037] The present invention is provided with a cleaning pressure relief pipeline including a second water pump and a pressure relief valve, and the pressure relief valve is provided with a water passage, a pressure relief port, an actuating port and a valve core, the second water pump is used to transport the water stored in the water tank to the first liquid inlet of the switching valve through the water passage, the actuating port is connected to the first water pump, and the valve core switches the circulation and closing of the pressure relief port and the water passage by the elastic force of the elastic element or the pressure of the water from the actuating port. The cleaning pressure relief pipeline is used to clean the milk circuit and relieve the pressure of the pressurized water.

[0038] The pressure relief valve is a mechanical valve, which does not require electrical control, is small in size and low in cost. Moreover, it is only necessary to connect a water pipe between the first water pump and the pressure relief valve to cooperate with the elastic element to cause the valve core to move to switch the flow and closure of the pressure relief port and the water passage. The water pipe is easy to deform and bend, and is easy to lay out inside the coffee machine, occupying a small space. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the circulating water flow of the first water pump of the coffee machine milk line cleaning system according to Embodiment 1 of the present invention;

[0040] Figure 2 This is a schematic diagram of brewing coffee with the milk path cleaning system of a coffee machine according to Embodiment 1 of the present invention;

[0041] Figure 3 This is a schematic diagram of emulsifying milk in the milk path cleaning system of a coffee machine according to Example 1 of the present invention;

[0042] Figure 4 Schematic diagram of a coffee machine milk circuit cleaning system for cleaning a milk circuit according to Embodiment 1 of the present invention;

[0043] Figure 5Schematic diagram of the coffee machine milk line cleaning system according to Embodiment 1 of the present invention releasing pressure through a pressure relief valve;

[0044] Figure 6 Schematic diagram of a coffee machine milk circuit cleaning system for cleaning a milk circuit according to Embodiment 2 of the present invention;

[0045] Figure 7 Schematic diagram of the coffee machine milk line cleaning system according to Embodiment 2 of the present invention releasing pressure through a pressure relief valve;

[0046] Figure 8 It is a schematic diagram of the pressure relief valve of Example 1 of the present invention closing the pressure relief port when it is in a normal state;

[0047] Fig. 9 It is a schematic diagram of the pressure relief valve of Example 1 of the present invention when the pressure relief port is opened to release pressure;

[0048] Fig.10 It is a schematic diagram of the pressure relief valve of Example 2 of the present invention when the pressure relief port is normally opened;

[0049] Fig.11 It is a schematic diagram of the pressure relief valve of Example 2 of the present invention when the pressure relief port is closed;

[0050] Fig.12 It is a schematic diagram showing that the second liquid inlet and the liquid outlet are connected when the switching valve of the present invention is in a normal state;

[0051] Fig.13 It is a schematic diagram of the switching valve of the present invention being in a state where the first liquid inlet and the liquid outlet are connected;

[0052] Description of the numbers in the figure:

[0053] 100 Switching Valve:

[0054] 110 valve cavity, 111 tubular valve body, 112 first end cover, 113 second end cover, 114 first liquid inlet, 115 second liquid inlet, 116 liquid outlet, 117 annular flange, 118 first cavity, 119 second cavity;

[0055] 120 valve core assembly: 121 tubular piston seat, 122 support seat, 123 valve hole, 124 first spring, 125 valve plug, 126 sealing block, 127 ring groove, 128 sealing ring, 129 radial hole;

[0056] 130 circulation gap;

[0057] 140 second spring;

[0058] 201 water tank, 202 first water pump, 203 heater, 204 coffee brewing component, 205 emulsifier, 206 milk tank, 207 second water pump, 208 second stop valve, 210 first stop valve, 211 water return box, 213 safety valve, 214 check valve, 215 coffee outlet, 216 flow meter;

[0059] 300 coffee cups;

[0060] 400 pressure relief valve, 410 valve body, 411 inner cavity, 412 water passage, 413 pressure relief port, 414 actuating port, 415 valve port, 420 valve core, 421 connecting groove, 430 elastic element, 440 first sealing ring, 450 second sealing ring. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention are intended to cover non-exclusive inclusions. For example, a method or product comprising a series of technical features is not necessarily limited to those technical features clearly listed, but may also include other technical features that are not clearly listed and can be included in the method or product.

[0063] In the description of the present invention, it is necessary to understand that the technical features defined by the terms "first", "second" and the like with sequential concepts are only for the purpose of clearly describing the defined technical features so that the defined technical features can be clearly distinguished from other technical features, but do not represent such naming in actual implementation, and therefore cannot be understood as a limitation of the present invention.

[0064] The present invention is described in detail below in conjunction with specific embodiments and accompanying drawings.

[0065] Various embodiments of the present invention relate to a switching valve 100. The switching valve 100 is as follows: Figure 12-13As shown, it includes a first liquid inlet 114, a second liquid inlet 115 and a liquid outlet 116. The first liquid inlet 114 is used to input pressure water, the second liquid inlet 115 is used to suck milk from a milk tank, and the liquid outlet 116 is used to connect an emulsifier. The switching valve 100 is configured so that the first liquid inlet 114 and the second liquid inlet 115 are selectively connected to the liquid outlet 116 to flow out pressure water or milk from the liquid outlet. The second liquid inlet 115 and the liquid outlet 116 are kept in normal communication for the emulsifier to suck milk from the milk tank. When pressure water is delivered to the first liquid inlet 114 of the switching valve, the first liquid inlet 114 is switched to be connected to the liquid outlet 116 to clean the liquid outlet and the subsequent pipelines and the emulsifier.

[0066] Specifically, the switching valve includes a valve cavity 110 and a valve core assembly 120 disposed in the valve cavity.

[0067] The valve chamber 110 is surrounded by a tubular valve body 111 and a first end cap 112 and a second end cap 113 which are separately connected to the two ends of the tubular valve body. The first end cap 112 and the second end cap 113 are preferably connected to the two ends of the tubular valve body by threads. The valve chamber 110 has a first liquid inlet 114, a second liquid inlet 115 and a liquid outlet 116. The first liquid inlet 114 is provided at the first end cap 112. The second liquid inlet 115 is provided at the second end cap 113. An annular flange 117 is provided at one end of the second liquid inlet 115 located in the valve chamber for sealing the second liquid inlet when the valve core assembly moves to the second position. The liquid outlet 116 is provided at the lower end of the side wall of the tubular valve body 111 near the second end cap.

[0068] The valve core assembly 120 is piston-shaped and arranged in the valve cavity 110 and can be moved between the first position and the 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 arranged at the center of the tubular piston seat 121 and is open to the first cavity 118. The support seat 122 is assembled at the lower end of the tubular piston seat 121 by threading. 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 to apply an elastic force to the valve plug toward the valve hole. When there is no pressure water at the first liquid inlet, the elastic force of the first spring 124 causes the valve plug 125 to block the valve hole 123. The sealing block 126 is embedded in the lower end of the support seat 122 and corresponds to the second liquid inlet 115, and is used 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 sleeved in the annular groove 127. The sealing ring 128 is squeezed between the inner wall of the tubular valve body 111 and the annular groove 127 to achieve sealing, preventing the liquid from flowing along the length direction of the tubular valve body at the sealing ring position. In addition, the valve core assembly 120 is located Fig.12In the first position shown, the valve cavity 110 is separated into a first cavity 118 and a second cavity 119 by the valve core assembly 120, and the first liquid inlet 114 is connected to the first cavity 118. When the valve core assembly 120 is in the second position, the second liquid inlet 115 and the liquid outlet 116 are connected to the second cavity 119. In addition, 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 the position where the valve core assembly 120 is moved. Fig.13 In the second position, the valve hole 123 is connected to the liquid outlet 116 through the radial hole 129 and the flow gap 130. In other embodiments, a flow gap is provided between the support seat 122 and the tubular piston seat 121, and the valve hole is connected to the liquid outlet through the flow gap when the valve core assembly moves to the second position.

[0069] The second spring 140 is sleeved outside the tubular piston seat 121 and its two ends are supported on the tubular piston seat 121 and the tubular valve body 111 respectively. The second spring 140 applies an upward elastic force to the tubular piston seat 121, which causes the valve core assembly 120 to be located in the first cavity when there is no pressure water. Fig.12 First position shown.

[0070] Therefore, under normal conditions, the valve core assembly 120 is Fig.12 As shown in the first position, the first liquid inlet 114 is blocked from the liquid outlet 116, and the second liquid inlet 115 is connected to the liquid outlet 116 to allow milk from the second liquid inlet to flow. Fig.12 When pressure water is input to the first liquid inlet 114 in the state shown, the pressure water overcomes the elastic force of the second spring 140 to move the valve core assembly 120 to the position Fig.13 In the second position shown, the second liquid inlet 115 is blocked, and the pressure water also overcomes the elastic force of the first spring 124 to push the valve plug 125 away from the valve hole 123, so that the first liquid inlet 114 is connected to the liquid outlet 116 through the valve hole 123, the radial hole 129 and the flow gap 130 for the pressure water from the first liquid inlet to flow. Fig.12 and Fig.13 The dashed line with an arrow in the figure indicates the flow direction of the liquid.

[0071] The switching valve, when applied to the milk circuit of a coffee machine, can switch the delivery of milk and pressurized water, so as to emulsify the milk or clean the milk circuit.

[0072] Example 1

[0073] Figure 1-5The structure of the coffee machine milk circuit cleaning system and its different working states are shown. The coffee machine milk circuit cleaning system includes a water tank 201, a first water pump 202, a heater 203, an emulsifier 205, a milk tank 206 and a switching valve 100. The first water pump 202 is used to transport the water stored in the water tank 201 to the heater 203, the heater 203 is used to vaporize the water into steam and transport the steam to the emulsifier 205, and the emulsifier 205 draws milk from the milk tank through the liquid outlet 116 and the second liquid inlet 115 of the switching valve 100 and emulsifies the milk.

[0074] The coffee machine milk circuit cleaning system is also equipped with a cleaning pressure relief pipeline, which includes a second water pump 207 and a pressure relief valve 400. The pressure relief valve 400 includes a water passage 412, a pressure relief port 413, an actuation port 414 and a valve core 420. The second water pump 207 is used to transport the water stored in the water tank 201 to the first liquid inlet 114 of the switching valve 100 through the water passage 412. The actuation port 414 is connected to the first water pump 202. The valve core 420 switches the flow and closing of the pressure relief port 413 and the water passage 412 by the elastic force of the elastic element 430 or the pressure of the water from the actuation port 414.

[0075] like Figure 8-9 As shown in FIG. 1 , the pressure relief valve 400 is embodied as a structure in which the pressure relief port 413 is normally closed. Figure 8 As shown in FIG. 1 , the pressure relief port 413 and the water passage 412 are kept closed by the upward elastic force of the elastic element 430. Fig. 9 As shown, the pressure of water from the actuation port 414 overcomes the elastic force of the elastic element 430 and moves downward to allow the pressure relief port 413 to communicate with the water passage 412. The pressure relief valve 400 includes a valve body 410, the water passage 412 runs through the valve body 410, an inner cavity 411 connected to the water passage 412 is provided in the valve body 410, the pressure relief port 413 is located at one side of the water passage 412 and communicates with the inner cavity 411, the valve core 420 is located in the inner cavity 411 of the valve body, the valve core 420 includes a first sealing ring 440, a second sealing ring 450, and a communicating groove 421 located between the first sealing ring and the second sealing ring. The first sealing ring and the second sealing ring are as shown in FIG. Figure 8 As shown, the valve core is located on both sides of the pressure relief port to separate the pressure relief port 413 from the water passage 412 to close the connection between them. Fig. 9 After moving downward, the second sealing ring 450 is staggered away from the pressure relief port 413 and connects the pressure relief port with the water passage through the connecting groove 421. Thus, the pressure relief valve is kept compact in structure and small in size.

[0076] In addition, the first water pump 202 and the second water pump 207 are both plunger pumps for providing stable water pressure. The pressure of water delivered by the first water pump is greater than the pressure of water delivered by the second water pump. The water pump model is selected according to the needs to save manufacturing costs. The outlet end of the first water pump is connected to a safety valve. It is used to release pressure when the water delivery pressure of the first water pump is relatively high, so as to keep the pressure of water delivered by the first water pump to the downstream stable.

[0077] Further, according to the flow direction of water, the downstream of the heater 203 is connected to the check valve 214 and the coffee brewing component 205; the pipeline between the heater 203 and the check valve 214 is connected to the emulsifier 205 via the steam pipeline, and the first stop valve 210 for controlling the flow and closing of the steam pipeline is arranged in the steam pipeline; the pipeline between the heater 203 and the check valve 214 is also connected to the pipeline between the first water pump 202 and the water tank 201 via the return pipeline, and the second stop valve 208 for controlling the flow and closing of the return pipeline is arranged in the return pipeline. Accordingly, the water flow can be made to circulate in the first water pump and the heater as needed during the startup or operation of the coffee machine. When the first water pump is started for the first time after the machine is turned on, the circulation is started, and the pressure at the outlet end of the first water pump is small, which is conducive to the startup of the first water pump. In the working process, since the water temperature required for brewing coffee is lower than the temperature of the steam when emulsifying milk, when emulsifying milk first and then brewing coffee, the heater is easy to heat the delivered cold water to overheat due to the high temperature, which is not conducive to brewing coffee. After turning on the cycle, the circulating water flow can cool the heater, ensuring that the hot water temperature output by the heater is consistent when brewing coffee.

[0078] As mentioned above, when the first water pump is started for the first time after the machine is turned on, the coffee machine works according to the following steps:

[0079] (a) If Figure 1 As shown, the first water pump 202 transports the stored water from the water tank 201 to the heater 203 and returns the water to the first water pump 202 through the return water pipeline; during this period, the first stop valve 210 in the steam pipeline is closed, and the second stop valve 208 in the return water pipeline is turned on.

[0080] (b) Close the second stop valve 208 in the return water pipeline to close the return water pipeline.

[0081] (c) If Figure 2 As shown, the first water pump 202 delivers water to the heater 203, and the heater 203 heats the water into hot water, and the hot water flows to the coffee brewing component 204 through the check valve 214 for brewing coffee, and the coffee beverage flows into the coffee cup 300 through the coffee outlet 215. Meanwhile, the first stop valve 210 in the steam pipeline is closed, and the second stop valve 208 in the return water pipeline is closed.

[0082] Or, if Figure 3As shown, the first water pump 202 delivers water to the heater 203, and the heater 203 heats the water into steam. The steam flows to the emulsifier 205 through the first stop valve 210, and the emulsifier draws milk from the milk tank 206 through the liquid outlet 116 and the second liquid inlet 115 of the switching valve and emulsifies the milk. During this period, the first stop valve 210 in the steam pipeline is turned on, and the second stop valve 208 in the return water pipeline is closed.

[0083] The working method of the coffee machine of this embodiment for emulsifying milk, cleaning the milk path and relieving pressure comprises the following steps:

[0084] (1) Emulsified milk: Figure 3 As shown, the first water pump 202 transports the water stored in the water tank 201 to the heater 203, the heater 203 vaporizes the water into steam and transports the steam to the emulsifier 205, and the emulsifier 205 draws milk from the milk tank 206 through the second liquid inlet 115 and the liquid outlet 116 of the switching valve 100 by the flow of steam and emulsifies the milk; during this period, the first stop valve 210 in the steam pipeline is turned on, and the second stop valve 208 in the return water pipeline is closed.

[0085] (2) Cleaning the milk line: Figure 4 As shown, the second water pump 207 delivers the water in the water tank 201 to the first liquid inlet 114 of the switching valve 100 through the water passage 412 of the pressure relief valve 400, and the switching valve 100 switches to connect the first liquid inlet 114 with the liquid outlet 116 to clean the liquid outlet 116 and the subsequent pipelines and emulsifier. During this time, the first stop valve 210 in the steam pipeline is closed; the second stop valve 208 in the return pipeline is closed; the first water pump 202 stops working, and the valve core 420 of the pressure relief valve 400 is closed. Figure 8 As shown, the pressure relief port 413 and the water passage 412 are kept closed by the elastic force of the elastic element 430 .

[0086] (3) Pressure relief: Figure 5 As shown, the first water pump 202 is started to deliver water to the actuation port 414 of the pressure relief valve 400, and the valve core 420 overcomes the elastic force of the elastic element 430 by the water pressure from the actuation port 414 and moves downward to make the pressure relief port 413 of the pressure relief valve and the water passage 412 maintain flow to relieve pressure, and the switching valve can be switched from Fig.13 The status shown is reset to Fig.12 The initial state shown. During this period, the second water pump 207 is stopped.

[0087] During the working process, since the water temperature required for brewing coffee is lower than the temperature of the steam when emulsifying milk, when emulsifying milk first and then brewing coffee, the heater will easily overheat the delivered cold water due to the high temperature, which is not conducive to brewing coffee. At this time, work according to the following steps:

[0088] (A) Figure 3As shown, the first water pump 202 delivers water to the heater 203, the heater heats the water into steam, and the steam flows to the emulsifier 205 for the emulsifier to draw milk from the milk tank 206 through the second liquid inlet 115 and the liquid outlet 116 of the switching valve 100 and emulsify the milk. During this period, the first stop valve 210 in the steam pipeline is turned on, and the second stop valve 208 in the return water pipeline is closed.

[0089] (B) Figure 1 As shown, the first water pump 202 delivers the stored water from the water tank to the heater 203, and the water flows back to the first water pump through the second stop valve 208 of the return water pipeline. During this time, the first stop valve 210 in the steam pipeline is closed, and the second stop valve 208 in the return water pipeline is open. The circulating water flow can cool the heater to ensure that the temperature of the hot water output by the heater is consistent when brewing coffee.

[0090] (C) Figure 2 As shown, the return water pipeline is closed, and the first water pump 202 delivers water to the heater 203, and the heater heats the water into hot water, and the hot water flows to the coffee brewing component 204 for brewing coffee. Meanwhile, the first stop valve 210 in the steam pipeline is closed, and the second stop valve 208 in the return water pipeline is closed.

[0091] As described above, the coffee machine of this embodiment uses the cleaning pressure relief pipeline to clean the milk circuit and relieve the pressure of the pressurized water. In addition, the valve core switches the flow and closure of the pressure relief port and the water passage by the elastic force of the elastic element or the pressure of the water from the actuating port. When the pressure relief port and the water passage are closed, they are used to clean the milk circuit, and when the pressure relief port and the water passage are in communication, they are used to relieve the pressure of the pressurized water.

[0092] The pressure relief valve is a mechanical valve, which does not require electrical control, is small in size and low in cost. Moreover, it is only necessary to connect a water pipe between the first water pump and the pressure relief valve to cooperate with the elastic element to cause the valve core to move to switch the flow and closure of the pressure relief port and the water passage. The water pipe is easy to deform and bend, and is easy to lay out inside the coffee machine, occupying a small space.

[0093] Example 2

[0094] Compared with the first embodiment, the difference of this embodiment is only that the structure of the pressure relief valve 400 is different. In this embodiment, the pressure relief valve 400 is embodied as a structure in which the pressure relief port 413 is normally open. The valve core 420 allows the pressure relief port 413 to maintain flow with the water passage 412. The valve core 420 closes the pressure relief port 413 and the water passage 412. Specifically, as Figure 10-11 As shown, the pressure relief valve 400 includes a valve body 410, a water passage 412 passes through the valve body 410, an inner cavity 411 connected to the water passage and a valve port 415 are provided in the valve body 410, a pressure relief port 413 is located at one side of the water passage 412 and connected to the inner cavity 411, and a valve core 420 is located in the inner cavity 411 of the valve body. Fig.10 As shown, the valve core 420 moves upward by the elastic force of the elastic element 430 and leaves the valve port 415, so that the pressure relief port 413 and the water passage 412 remain in communication. Fig.11 As shown, the water pressure from the actuation port 414 overcomes the elastic force of the elastic element 430 and moves downward to block the valve port 415, thereby closing and blocking the pressure relief port 413 and the water passage 412. Thus, the pressure relief valve is kept compact and small in size.

[0095] Based on the structure of the pressure relief valve, such as Figure 6 When cleaning the pipeline, corresponding to step (2) of embodiment 1, the first water pump 202 is started to deliver water to the actuating port 414 of the pressure relief valve 400, and the valve core 420 is as shown in FIG. Fig.11 As shown, the pressure of the water from the actuation port 414 is used to close the pressure relief port and the water passage, so that the water from the second water pump flows to the switching valve and the emulsifier for cleaning. Figure 7 As shown in FIG. 1 , when the pressure is released, corresponding to step (3) of Example 1, the first water pump 202 stops working, and the valve core 420 of the pressure relief valve 400 is as shown in FIG. Fig.10 As shown in the figure, the elastic element 430 moves downward to promote the flow of the pressure relief port and the water passage, and the pressure water of the first liquid inlet of the switching valve 100 is released, and the switching valve is switched from Fig.13 The status shown is reset to Fig.12 Status shown.

[0096] The pressure relief valve in the above embodiment can be used as a reference. Figure 12-13 The switching valve shown is sealed at an appropriate location and assembled using a split structure.

[0097] In the above embodiment, the water flowing out of the water tank can be measured by a flow meter, and the end timing of the corresponding working mode can be controlled based on the flow rate.

[0098] The switching valve may be disposed inside the milk tank 206 or outside the milk tank 206 as required.

[0099] exist Figure 1-7 In each working mode, the flow of the fluid is indicated by arrows, and the direction of the arrows indicates the flow direction of the fluid. The position without an arrow in the pipeline indicates that there is no fluid flow.

[0100] exist Fig. 9 , Fig.10 In the figure, the pressure relief path is indicated by a dotted line marked with an arrow.

Claims

1. A coffee machine milk line cleaning system, comprising a water tank (201), a first water pump (202), a heater (203), an emulsifier (205), a milk tank (206) and a switching valve (100); The first water pump is used to transport the water stored in the water tank to the heater, the heater is used to vaporize the water into steam and transport the steam to the emulsifier, the milk tank is connected to the emulsifier so that the emulsifier draws milk from the milk tank and emulsifies the milk; The switching valve (100) comprises a first liquid inlet (114), a second liquid inlet (115) and a liquid outlet (116); the first liquid inlet (114) is used to input pressurized water, the second liquid inlet (115) is used to suck milk from a milk tank, and the liquid outlet (116) is connected to an emulsifier; the switching valve is configured so that the first liquid inlet (114) and the second liquid inlet (115) are selectively connected to the liquid outlet (116) so that pressurized water or milk flows out from the liquid outlet; the second liquid inlet and the liquid outlet are kept in normal communication so that the emulsifier can suck milk from the milk tank, and when pressurized water is delivered to the first liquid inlet of the switching valve, the first liquid inlet is switched to be connected to the liquid outlet so as to clean the liquid outlet and the pipeline and the emulsifier thereafter; Its characteristics are: A cleaning pressure relief pipeline is provided, the cleaning pressure relief pipeline comprising a second water pump (207) and a pressure relief valve (400), the pressure relief valve (400) comprising a water passage (412), a pressure relief port (413), an actuating port (414) and a valve core (420), the second water pump (207) being used to deliver the stored water in the water tank to the first liquid inlet (114) of the switching valve (100) through the water passage (412), the actuating port (414) being connected to the first water pump (202), and the valve core (420) switching the flow and closing of the pressure relief port (413) and the water passage (412) by means of the elastic force of the elastic element (430) or the pressure of the water from the actuating port (414).

2. The coffee machine milk path cleaning system according to claim 1, characterized in that: The valve core (420) keeps the pressure relief port (413) and the water passage (412) closed by the elastic force of the elastic element (430), and the valve core (420) moves by the pressure of water from the actuating port (414) to allow the pressure relief port and the water passage to flow.

3. The coffee machine milk path cleaning system according to claim 2, characterized in that: The pressure relief valve (400) comprises a valve body (410), a water passage (412) passing through the valve body, an inner cavity (411) connected to the water passage is provided in the valve body, a pressure relief port (413) is located at one side of the water passage (412) and connected to the inner cavity (411), a valve core (420) is located in the inner cavity (411) of the valve body, the valve core (420) comprises a first sealing ring (440), a second sealing ring (450) and a connecting groove (421) between the first sealing ring and the second sealing ring, the first sealing ring and the second sealing ring are located at two sides of the pressure relief port (413) to close the pressure relief port and the water passage, the first sealing ring or the second sealing ring is staggered with the pressure relief port and the pressure relief port is connected to the water passage via the connecting groove (421).

4. The coffee machine milk path cleaning system according to claim 1, characterized in that: The valve core (420) uses the elastic force of the elastic element (430) to keep the pressure relief port and the water passage flowing. The valve core (420) moves by the pressure of water from the actuating port (414) to close the pressure relief port and the water passage.

5. The coffee machine milk path cleaning system according to claim 4, characterized in that: The pressure relief valve (420) comprises a valve body (410), a water passage (412) passing through the valve body (410), an inner cavity (411) connected to the water passage and a valve port (415) are provided in the valve body (410), a pressure relief port (413) is located at one side of the water passage (412) and communicates with the inner cavity (411), a valve core (420) is located in the inner cavity (411) of the valve body, the valve core (420) leaves the valve port (415) to allow the pressure relief port and the water passage to maintain flow, and the valve core (420) blocks the valve port (415) to close the pressure relief port and the water passage.

6. The coffee machine milk path cleaning system according to any one of claims 1 to 5, characterized in that: The first water pump and the second water pump are both plunger pumps.

7. The coffee machine milk path cleaning system according to any one of claims 1 to 5, characterized in that: The pressure of water delivered by the first water pump is greater than the pressure of water delivered by the second water pump.

8. The coffee machine milk path cleaning system according to any one of claims 1 to 5, characterized in that: The outlet end of the first water pump is connected to a safety valve (213).

9. The coffee machine milk path cleaning system according to any one of claims 1 to 5, characterized in that: The heater (203) is connected to the check valve (214) and the coffee brewing assembly (204); The pipeline between the heater (203) and the check valve (214) is connected to the emulsifier (205) via a steam pipeline, and a first stop valve (210) for controlling the flow and closing of the steam pipeline is arranged in the steam pipeline; The pipeline between the heater (203) and the check valve (214) is also connected to the pipeline between the first water pump (202) and the water tank (201) via a return pipeline, and a second stop valve (208) is arranged in the return pipeline to control the flow and closing of the return pipeline.

10. Pressure relief valve, characterized by: The invention comprises a water passage (412), a pressure relief port (413), an actuating port (414) and a valve core (420). The valve core (420) switches the flow and closing of the pressure relief port (413) and the water passage (412) by means of the elastic force of an elastic element (430) or the pressure movement of water from the actuating port (414).

11. The pressure relief valve according to claim 10, characterized in that: The valve core (420) keeps the pressure relief port and the water passage closed by the elastic force of the elastic element (430), and the valve core (420) moves by the pressure of water from the actuating port (414) to allow the pressure relief port and the water passage to flow.

12. The pressure relief valve according to claim 10 or 11, characterized in that: The pressure relief valve comprises a valve body (410), a water passage (412) passes through the valve body (410), an inner cavity (411) connected to the water passage is provided in the valve body, a pressure relief port (413) is located at one side of the water passage (412) and communicates with the inner cavity (411), a valve core (420) is located in the inner cavity (411) of the valve body, the valve core (420) comprises a first sealing ring (440), a second sealing ring (450) and a connecting groove (421) between the first sealing ring and the second sealing ring, the first sealing ring and the second sealing ring are located at two sides of the pressure relief port (413) to close the pressure relief port and the water passage, the first sealing ring or the second sealing ring is staggered with the pressure relief port and the pressure relief port is connected with the water passage through the connecting groove (421).

13. The pressure relief valve according to claim 10, characterized in that: The valve core (420) uses the elastic force of the elastic element (430) to keep the pressure relief port and the water passage flowing, and the valve core moves by the pressure of water from the actuating port (414) to close the pressure relief port and the water passage.

14. The pressure relief valve according to claim 10 or 13, characterized in that: The pressure relief valve (400) comprises a valve body (410), a water passage (412) passing through the valve body, an inner cavity (411) connected to the water passage and a valve port (415) being provided in the valve body, a pressure relief port (413) being located at one side of the water passage (412) and communicating with the inner cavity, a valve core (420) being located in the inner cavity (411) of the valve body, the valve core (420) leaving the valve port (415) allowing the pressure relief port and the water passage to maintain flow, and the valve core (420) blocking the valve port (415) closing the pressure relief port and the water passage.

15. A coffee machine operating method, characterized in that The following steps are involved: (1) Emulsifying milk: the first water pump (202) transports the water stored in the water tank (201) to the heater (203), the heater (203) vaporizes the water into steam and transports the steam to the emulsifier (205), and the emulsifier (205) draws milk from the milk tank (206) through the second liquid inlet (115) and the liquid outlet (116) of the switching valve (100) by the flow of steam and emulsifies the milk; (2) Cleaning the milk circuit: the second water pump (207) transports the stored water in the water tank (201) to the first liquid inlet (114) of the switching valve (100) through the water passage (212) of the pressure relief valve (400), and the switching valve (100) switches so that the first liquid inlet (114) is connected to the liquid outlet (116) to clean the liquid outlet and the subsequent pipelines and the emulsifier; (3) Pressure relief: The valve core (420) of the pressure relief valve (400) is moved to allow the pressure relief port (413) of the pressure relief valve to flow with the water passage (412) to relieve pressure.

16. The coffee machine operating method according to claim 15, characterized in that: When executing step (2), the first water pump (202) stops working, and the valve core (420) of the pressure relief valve keeps the pressure relief port and the water passage closed by the elastic force of the elastic element (430); When executing step (3), the first water pump (202) is started to deliver water to the actuating port (414) of the pressure relief valve, and the valve core (420) moves by the pressure of the water from the actuating port (414) to cause the pressure relief port and the water passage to flow.

17. The coffee machine operating method according to claim 15, characterized in that: When executing step (2), the first water pump (202) is started to deliver water to the actuating port (414) of the pressure relief valve, and the valve core (420) uses the water pressure from the actuating port (414) to keep the pressure relief port and the water passage closed; When executing step (3), the first water pump (202) stops working, and the valve core (420) of the pressure relief valve moves by the elastic force of the elastic element (430) to promote the flow of the pressure relief port and the water passage.

18. The coffee machine operating method according to any one of claims 15 to 17, characterized in that The following steps are involved: (a) the first water pump (202) transports the stored water from the water tank to the heater (203) and returns the water to the first water pump through the return water pipeline; (b) Close the return water pipe; (c) The first water pump (202) supplies water to the heater (203), and the heater (203) heats the water into hot water, which flows to the coffee brewing component (204) for brewing coffee; or, the first water pump (202) supplies water to the heater (203), and the heater (203) heats the water into steam, which flows to the emulsifier (205) for the emulsifier to absorb milk from the milk tank and emulsify the milk.

19. The coffee machine operating method according to any one of claims 15 to 17, characterized in that The following steps are involved: (A) The first water pump (202) delivers water to the heater (203), the heater heats the water into steam, and the steam flows to the emulsifier (205) for the emulsifier to draw milk from the milk tank and emulsify the milk; (B) the first water pump (202) delivers the stored water from the water tank to the heater (203), and the water flows back to the first water pump through the return pipe; (C) The water return pipeline is closed, and the first water pump (202) delivers water to the heater (203). The heater heats the water into hot water, and the hot water flows to the coffee brewing component for brewing coffee.

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