Coffee machine powder pressing method

Abstract

The application discloses a coffee machine powder compacting method, and belongs to the coffee brewing technology. The existing coffee powder compacting technology has the problem that the compacting degree of coffee powder is difficult to control when the coffee powder capacity is different. The application sets the stroke of the coffee powder in the brewing cavity by moving the brewing plug from the initial position to the brewing cavity, so that the coffee powder with different capacities can be given different set strokes, and the coffee powder with each capacity can be compacted to a reasonable degree, and the porosity of the coffee powder is stable. After the coffee powder is compacted, the brewing plug is stopped, so that the compacted coffee powder in the brewing cavity is prevented from being continuously compacted in the process of being brewed and extracted by hot water, the flow rate of the hot water through the coffee powder is prevented from being reduced, the difference of the hot water pressure distribution is prevented from being increased, and the brewing efficiency and the coffee beverage quality are prevented from being reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coffee brewing, and particularly relates to a coffee machine powder pressing method. BACKGROUND

[0002] The existing coffee machine, through powder grinding, powder pressing and then using hot water with a certain pressure to brew and extract coffee powder into coffee beverage, wherein the powder pressing is one of the factors affecting the quality of coffee beverage. The coffee powder being pressed too dense or too loose is not conducive to the brewing and extraction of hot water on the coffee powder.

[0003] The utility model patent with the authorized announcement number CN211748887U discloses a coffee machine brewing mechanism, which comprises a brewing core assembly and a brewing head assembly. The brewing core assembly comprises a conversion connecting rod, an ejection connecting rod, a brewing cavity, a lower filter plate and an exhaust valve assembly formed by the brewing cavity and the lower filter plate. The brewing head assembly comprises a brewing head and a hydraulic device. The hydraulic device comprises a Y-shaped sealing ring, a piston cylinder cover, a hydraulic guide rod, a guide rod spring sleeved on the hydraulic guide rod, a cold water channel and a hot water channel. The cold water channel can drive the brewing head to compact coffee powder under the water pumping action of a water pump. The hot water channel can make hot water in a boiler flow through the brewing head to penetrate coffee powder for coffee extraction under the water pumping action of another water pump, so that coffee powder is pressed more thoroughly and coffee extraction is more sufficient.

[0004] The coffee machine brewing mechanism disclosed in the foregoing patent document has the following defects:

[0005] 1. When brewing large, medium or small cups of coffee beverage, the depth of coffee powder in the brewing cavity is different, and the degree of compaction of the coffee powder is difficult to control, and the void ratio of the coffee powder is unstable, especially when the capacity of the coffee powder is different. According to experience, no matter how much the capacity of the coffee powder in the brewing cavity is, the coffee powder should be compacted to a reasonable degree, but not too dense or too loose, which is a key factor for ensuring the quality of the final brewed and extracted coffee beverage in the powder pressing link.

[0006] 2. Due to the existence of water pump pressure, the compacted coffee powder in the brewing cavity will be further compacted during the process of being brewed and extracted by hot water. The coffee powder will be soaked in hot water and then compacted, which will greatly reduce the flow rate of hot water through the coffee powder, and the pressure distribution of hot water will also increase the difference, thus causing the reduction of brewing efficiency and the quality of coffee beverage. SUMMARY

[0007] The technical problem to be solved by the present application and the technical task proposed are to overcome the defect that the degree of compaction of coffee powder is difficult to control when the capacity of coffee powder is different in the existing coffee powder compaction technology, and to provide a coffee machine powder compaction method, so that coffee powder of different capacities can be compacted to a reasonable degree, and the quality of coffee beverage is not affected in the powder compaction link.

[0008] To achieve the purpose of the present application, the coffee machine powder compaction method of the present application is characterized in that: the capacity of coffee powder in the brewing chamber is set by the brewing plug moving from the initial position to the brewing chamber to set the stroke for compacting the coffee powder in the brewing chamber, and the brewing plug is reset to the initial position after brewing.

[0009] The method of the present application sets the stroke for compacting the coffee powder in the brewing chamber by the brewing plug moving from the initial position to the brewing chamber, so that different capacities of coffee powder can be given different set strokes, ensuring that coffee powder of each capacity can be compacted to a reasonable degree, and the void ratio of coffee powder is stable.

[0010] The method of the present application also stops the brewing plug after compacting the coffee powder, avoiding the decrease of the flow rate of hot water through the coffee powder, the increase of the difference of hot water pressure distribution, and the final decrease of the brewing efficiency and the quality of coffee beverage caused by the continued compaction of the coffee powder in the brewing chamber during the process of being brewed and extracted by hot water.

[0011] In order to facilitate users to make coffee beverages of different capacities, the capacity of coffee powder in the brewing chamber is selected on the coffee machine.

[0012] In order to simplify the operation of the user, the set stroke is a constant for the selected capacity of coffee powder. That is, no matter which capacity of coffee beverage the user chooses to make, there is a corresponding set stroke, and the user does not need to perform targeted operation to determine the set stroke.

[0013] Since the coffee powder grinded by the coffee bean grinder has different thickness, and the compression ratio of the coffee powder is different when it is compacted, the setting stroke is related to the thickness of the coffee powder, and the setting stroke is smaller when the coffee powder is thicker, and the setting stroke is larger when the coffee powder is thinner. In the actual operation of the coffee machine, there may be errors no matter which capacity of coffee powder is selected. When the actual capacity of the coffee powder is different from the standard value of the selected capacity, the brewing plug moves the setting stroke, and it is difficult to compact the coffee powder to the appropriate density. For example, when the actual capacity of the coffee powder is less than the standard value of the selected capacity, the setting stroke of the brewing plug is greater than the actual powder compression stroke, and the coffee powder will be compacted to be loose. When the actual capacity of the coffee powder is greater than the standard value of the selected capacity, the setting stroke of the brewing plug is less than the actual powder compression stroke, and the coffee powder will be compacted to be dense. In order to adapt to the error of the capacity of the coffee powder, that is, when the capacity of the coffee powder has an error, the coffee powder can still be compacted to an appropriate degree. To this end, the setting stroke includes an idle stroke and a powder compression stroke, and the following steps are performed:

[0014] (1) Idle stroke: the brewing plug moves from the initial position to the brewing chamber until it contacts the coffee powder, and the distance of the idle stroke and the capacity of the coffee powder in the brewing chamber are determined;

[0015] (2) Powder compression stroke: the brewing plug continues to move the powder compression stroke after contacting the coffee powder to compact the coffee powder;

[0016] (3) Reset stroke: the brewing plug is reset to the initial position after brewing;

[0017] Wherein:

[0018] △L = (L-L0)*(1-k),

[0019] △L is the distance of the powder compression stroke,

[0020] L is the distance between the bottom surface of the brewing plug and the bottom surface of the brewing chamber when the brewing plug is in the initial position,

[0021] L0 is the distance of the idle stroke,

[0022] (L-L0) is the depth corresponding to the capacity of the coffee powder before being compacted,

[0023] k is the compression ratio, which is the ratio of the volume of the coffee powder after being compacted to the volume before being compacted, and is a constant.

[0024] Accordingly, no matter how much the capacity of the coffee powder is, the brewing plug calculates the powder compression stroke when it contacts the coffee powder and actually moves the powder compression stroke, avoiding powder compression errors.

[0025] In particular, k is 40%-70%.

[0026] Since the coffee powder ground by the coffee bean grinder has different fineness, and the compression ratio of the coffee powder is different when it is compacted, the k value is related to the fineness of the coffee powder, and the k value is larger when the coffee powder is coarser, and the k value is smaller when the coffee powder is finer.

[0027] Moreover, the fineness of the coffee powder is adjusted by the adjusting knob to determine the coffee bean grinder. That is, when the fineness of the coffee powder is adjusted by adjusting the coffee bean grinder through the adjusting knob, the k value should change with the fineness of the coffee powder to adapt to the fineness of the coffee powder.

[0028] Since the pressure of the powder pressing end surface of the brewing plug on the coffee powder is 0 when the brewing plug does not contact the compacted coffee powder, and the reaction force of the powder pressing end surface of the brewing plug on the coffee powder is also 0; when the brewing plug contacts and compacts the coffee powder, the pressure of the powder pressing end surface of the brewing plug on the coffee powder instantaneously increases, and the reaction force of the powder pressing end surface of the brewing plug on the coffee powder also instantaneously increases. Therefore, in an embodiment, the contact of the brewing plug with the coffee powder is sensed by the pressure sensor, and the pressure sensor can accurately sense the change in pressure to ensure that the actual powder pressing stroke of the brewing plug is consistent with the set stroke.

[0029] In order to control the accurate movement of the brewing plug, the brewing plug is configured to move and reset from the initial position to the brewing chamber by a threaded transmission mechanism, and the threaded transmission mechanism is driven by a motor through a speed change mechanism, and the powder pressing stroke is determined by the number of revolutions of the rotating shaft of the motor or the speed change mechanism.

[0030] In order to accurately position the brewing plug at the initial position, the initial position is determined by a position switch.

[0031] In order to achieve the purpose of the present application, the brewing unit of the present application comprises a brewer and a brewing plug assembly, the brewer has a brewing chamber, the brewing chamber is configured to perform a displacement action between a powder receiving position and a powder pressing and brewing position, and the brewing plug assembly has a brewing plug for pressing powder, characterized in that: the brewing plug is configured to move and reset from the initial position to the brewing chamber by a threaded transmission mechanism, and the threaded transmission mechanism is driven by a motor through a speed change mechanism, and a number of revolutions measuring device is configured for the rotating shaft of the motor or the speed change mechanism to determine the movement distance of the brewing plug.

[0032] The number of revolutions measuring device is configured to send the measured number of revolutions to a controller, and the controller is configured to determine (calculate or store) a preset value and instruct the motor to stop when the measured number of revolutions from the number of revolutions measuring device reaches the preset value, and to reverse drive the brewing plug to reset after brewing.

[0033] The brewing unit provides structural support for compacting the coffee powder to a suitable compacting degree.

[0034] In order to accurately control the moving stroke of the brewing plug, the screw transmission mechanism comprises a screw rod, a screw nut and an axial guide structure, the screw rod is arranged on the brewing plug, the screw nut is in transmission cooperation with the variable speed mechanism, and the brewing plug moves axially through the axial guide structure when the screw nut rotates relative to the screw rod through the threaded cooperation. Therefore, the moving distance in the powder pressing action of the brewing plug is determined by controlling the number of rotations of the screw rod.

[0035] In order to constrain the movement of the brewing plug and avoid the rotation of the brewing plug, the brewing plug assembly comprises a support for assembling the brewing plug, the axial guide structure comprises a guide block arranged on the support and a guide groove arranged on the brewing plug, and the guide block is located in the guide groove to guide the axial movement of the screw rod when the screw nut rotates relative to the screw rod through the threaded cooperation.

[0036] In order to calculate the moving stroke of the brewing plug, the number of rotations measuring device comprises a magnetic ring and a magnetic sensitive sensor, the magnetic ring is configured to rotate with the rotating shaft of the motor or the variable speed mechanism, and the magnetic sensitive sensor is adjacent to the magnetic ring for sensing the change of the magnetic field of the magnetic ring.

[0037] In order to position the brewing plug at the initial position, a position switch is arranged on the brewing plug to stop the brewing plug at the initial position when reset.

[0038] The present application aims at the capacity of coffee powder in the brewing chamber, which is set by the moving stroke of the brewing plug from the initial position to the brewing chamber for compacting the coffee powder in the brewing chamber. Therefore, different capacities of coffee powder can be given different set strokes, ensuring that coffee powder of each capacity can be compacted to a reasonable degree, and ensuring the stability of the void ratio of coffee powder.

[0039] The present application also stops the brewing plug after compacting the coffee powder, avoiding the decrease of the flow rate of hot water through the coffee powder, the increase of the difference of hot water pressure distribution and the final decrease of the brewing efficiency and the quality of coffee beverage caused by the continuous compaction of the compacted coffee powder in the brewing chamber during the process of being brewed and extracted by hot water.

[0040] The brewing plug is configured to move from the initial position to the brewing chamber and reset by the screw transmission mechanism, the screw transmission mechanism is driven by the motor through the variable speed mechanism, the rotating shaft of the motor or the variable speed mechanism is configured with a number of rotations measuring device for determining the moving distance of the brewing plug, and structural support is provided for compacting coffee powder to a suitable compaction degree. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The assembly position of the brewing device of the present application and the coffee machine shell is shown in the figure;

[0042] Figure 2 The schematic diagram of the brewing chamber of the brewing unit of the present application in the powder pressing and brewing position is shown in the figure;

[0043] Figure 3A cross-sectional view of the brewing chamber of the brewing unit of the present application in the powder receiving position;

[0044] Figure 4 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position;

[0045] Figure 5 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position; Figure 4 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position;

[0046] Figures 6-12 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position;

[0047] Figure 6 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position,

[0048] Figure 7 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position,

[0049] Figure 8 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position,

[0050] Figure 9 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position,

[0051] Figure 10 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position,

[0052] Figure 11 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position,

[0053] Figure 12 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position,

[0054] Figure 13 A view of the brewing chamber of the brewing unit of the present application in the powder receiving position,

[0055] Legend of the figures:

[0056] 100 brewing device, 101 brewing chamber, 102 ejector rod, 103 housing, 104 brewing chamber drive mechanism, 105 support plate;

[0057] 200 brewing plug assembly, 201 brewing plug, 202 motor, 203 gear mechanism, 204 screw rod, 205 bracket, 206 guide slot, 207 magnetic ring, 208 magnetic sensor, 209 nut, 210 pressure sensor;

[0058] 300 coffee maker, 301 machine housing, 302 water pump, 303 detector, 304 controller;

[0059] 401 coffee powder, 402 pressed coffee powder;

[0060] 500 boiler. Detailed Implementation

[0061] 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.

[0062] 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.

[0063] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings.

[0064] like Figures 2-3 The brewing unit shown includes a brewer 100 and a brewing plug assembly 200. This brewing unit provides structural support for tamping coffee grounds to the appropriate degree of compaction.

[0065] The brewing stopper assembly 200 is fixedly assembled in Figure 1 The coffee machine 300 shown is housed within a casing 301. The brewing stopper assembly 200 has a brewing stopper 201 for tamping coffee grounds. (As shown...) Figures 2-13 As shown, the brewing stopper 201 is configured to move and reset from its initial position into the brewing chamber via a threaded drive mechanism. This threaded drive mechanism is driven by a motor 202 via a speed-changing mechanism 203. A rotation metering device is configured on the shaft of the motor or speed-changing mechanism to determine the rotation distance of the brewing stopper. The rotation metering device is configured to send the measured rotation count to the controller. The controller is configured to determine (calculate or store) a preset value and, when the measured rotation count sent by the rotation metering device reaches that preset value, instruct the motor to stop. After brewing, the controller instructs the motor to reverse and drive the brewing stopper to reset.

[0066] In order to accurately control the movement of the brewing plug, the threaded transmission mechanism includes a screw 204, a nut 209 and an axial guide structure. The screw 204 is located on the brewing plug 201. The outer periphery of the nut 209 is made into a gear and is driven and engaged with the gear set as a speed change mechanism. When the nut 209 rotates relative to the screw 204 through the threaded engagement, the brewing plug 201 moves axially by means of the axial guide structure.

[0067] In order to restrict the movement of the brewing plug and avoid the rotation of the brewing plug, the brewing plug assembly 200 comprises a bracket 205 for assembling the brewing plug 201, an axial guiding structure comprising a guiding block provided on the bracket and a guiding groove 206 provided on the brewing plug, and when the nut rotates relative to the screw rod through the threaded cooperation, the guiding block is located in the guiding groove to guide the axial movement of the screw rod.

[0068] Therefore, the rotation of the motor can be converted into the axial movement of the brewing plug through the guiding of the speed change mechanism, the threaded transmission mechanism and the axial guiding structure, and the movement distance in the powder pressing action of the brewing plug can be determined by controlling the number of rotations of the screw rod.

[0069] As shown in Figure 2 , Figure 13 In order to calculate the movement stroke of the brewing plug, the number of rotations measuring device comprises a magnetic ring 207 and a magnetic sensitive sensor 208, the magnetic ring is configured to rotate with the rotating shaft of the motor, and the magnetic sensitive sensor is adjacent to the magnetic ring for sensing the change of the magnetic field of the magnetic ring. In other embodiments, the magnetic ring can also be configured to rotate with the rotating shaft of the speed change mechanism. Moreover, in other embodiments, the magnetic ring and the magnetic sensitive sensor can be replaced by photoelectric sensors and the like.

[0070] In order to position the brewing plug 201 at the initial position, a position switch is configured for the brewing plug, and when the brewing plug is reset, it touches the position switch to stop at the initial position, so as to determine the starting point of the movement stroke of the brewing plug in the powder pressing.

[0071] The brewing device 100 has a brewing chamber 101, the bottom of the brewing chamber 101 has a top rod 102, and the top of the top rod 102 is a supporting plate 105. When the top rod 102 is lowered, the supporting plate 105 is located at the bottom of the brewing chamber 101, and the brewing chamber 101 has a large enough capacity to receive coffee powder. When the top rod 102 is raised, the supporting plate 105 is located at the top of the brewing chamber 101 to lift the brewed powder cake 402 out of the brewing chamber. The brewing device 100 is detachably assembled in the machine shell 301, and after the brewing device 100 is assembled into the machine shell, it is clamped together with the brewing plug assembly 200. Moreover, the brewing chamber 101 is configured to perform a switching action between the powder receiving position shown in Figures 4-7 and Figure 12 and the powder pressing and brewing position shown in Figures 8-9 The brewing device 100 comprises a brewing chamber driving mechanism 104 for providing driving force for the switching of the brewing chamber and the lifting of the top rod.

[0072] In the coffee machine, the grinding device is usually adjusted by an adjusting knob to adjust the grinding gap for adjusting the fineness of the coffee powder. Therefore, in particular, this adjustment is set according to gears, such as gears 1, 2, 3, 4 and 5, which respectively represent the fineness of the coffee powder from fine to coarse, and a detector 303 is configured for the adjusting knob to transmit the gear information to the controller 304 of the coffee machine. Based on the foregoing structure of the brewing unit, the powder pressing can be performed in the manner of the following embodiments.

[0073] Example 1

[0074] The powdering step of this example is as follows:

[0075] 1.1 The user selects the capacity of coffee powder in the brewing chamber on the coffee machine 300, which is generally achieved by operating the corresponding button on the coffee machine, such as selecting a large cup, a medium cup or a small cup, and the capacity of coffee powder and the capacity of water used to brew the coffee powder are determined, and the setting stroke of the powdering of the brewing plug is also determined. For the selected capacity of coffee powder, the setting stroke is constant. After selecting the capacity of coffee powder, the coffee machine is started.

[0076] 1.2 The coffee bean grinding device of the coffee machine grinds the coffee beans into powder and falls into the brewing chamber 101 from the state shown in FIG. 1A until the grinding of powder is completed as shown in FIG. 1B. Figure 6 Figure 7 1.3 The brewing chamber 101 is indexed to the powdering and brewing position as shown in FIG. 1C under the driving of the brewing chamber driving mechanism 104 to prepare for powdering.

[0077] 1.4 The brewing plug 201 moves from the starting position to the brewing chamber 101 by a setting stroke to compact the coffee powder. Then the water pump 302 works to supply water, and the water heated by the boiler 500 flows into the brewing chamber 101 at a certain pressure to brew and extract the coffee powder. After the flow of hot water reaches a set value, the water pump stops supplying water. Figure 8

[0078] 1.5 As shown in FIG. 1D, the brewing plug 201 is reset to the initial position, and the top rod 102 is raised, and the powder cake 402 is lifted and ejected out of the brewing chamber.

[0079] 1.6 As shown in FIG. 1E, the brewing chamber 101 is indexed from the powdering and brewing position to the powder receiving position, and in the indexing process, the powder cake 402 is blocked by the shell 103 and falls; the powder cake is the accumulated cake-shaped form of the compacted coffee powder after brewing and extraction. Figure 10

[0080] 1.7 Finally, the brewing chamber 101 is reset to the powder receiving position, and the top rod 102 is lowered to the lowest position of the brewing chamber, and the next powder receiving, powdering and brewing can be performed. Figure 11

[0081]

[0082] ​​​​​In this embodiment, because the coffee grinder produces coffee powder of varying coarseness, and the compression ratio varies depending on the coarseness of the coffee powder, the set stroke is related to the coarseness of the coffee powder. A smaller set stroke is used when the coffee powder is coarser, and a larger set stroke is used when the coffee powder is finer. This is determined by the controller 304 based on the gear signal transmitted from the detector 303, thus linking the set stroke to the coarseness of the coffee powder; a smaller set stroke is used when the coffee powder is coarser, and a larger set stroke is used when the coffee powder is finer.

[0083] Example 2

[0084] In actual operation of a coffee machine, errors may occur regardless of the selected coffee powder capacity. Therefore, in this embodiment, the travel is defined as including an idle travel and a tamping travel. The idle travel is the distance the brewing stopper travels from its initial position to the position where it contacts the coffee powder, and the tamping travel is the distance the brewing stopper actually travels to tamp the coffee powder. This embodiment performs the following steps:

[0085] 2.1 The user selects the volume of coffee powder in the brewing chamber on the coffee machine 300, such as selecting a large, medium, or small cup. Since the volume of coffee powder obtained from grinding may have errors, in this embodiment, the selected volume of coffee powder is used to determine the volume of water for brewing the coffee powder, and the set stroke is not determined; then the coffee machine is started.

[0086] 2.2 The coffee machine's grinding unit grinds coffee beans into powder and then... Figure 6 The mixture falls into the brewing chamber 101 in the state shown, until... Figure 7 The grinding process is complete as shown.

[0087] 2.3 The brewing chamber 101 is repositioned under the drive of the brewing chamber drive mechanism 104. Figure 8 The powder pressing and brewing position is shown in the diagram; prepare to press the powder.

[0088] 2.4 Execution of idle stroke: The brewing stopper 201 moves from its initial position into the brewing chamber until it contacts the coffee grounds 401. Whether it contacts the coffee grounds is determined by the pressure sensor 210 disposed on the bottom surface of the brewing stopper (see...). Figure 13 The distance the machine moves during this process is called the idle stroke. Based on this, we can determine the distance of the idle stroke and the capacity of coffee powder in the brewing chamber. The distance of the idle stroke can be determined by calculating the number of screw revolutions, which can be obtained by calculating the number of motor revolutions and the transmission ratio.

[0089] 2.5 Perform the tamping stroke: From the moment the brewing plug 201 contacts the coffee powder 401, the brewing plug continues to move to tamp the coffee powder. The tamping stroke is also determined by the number of revolutions of the motor or speed-changing mechanism shaft.

[0090] In steps 2.4 and 2.5, the idle stroke and the powder compacting stroke are calculated by the controller of the coffee machine through the formula △L = (L-L0)*(1-k), wherein:

[0091] △L is the distance of the powder compacting stroke,

[0092] L is the distance between the bottom surface of the brewing plug and the bottom surface of the brewing chamber when the brewing plug is in the initial position,

[0093] L0 is the distance of the idle stroke,

[0094] (L-L0) is the depth corresponding to the volume of the coffee powder before being compacted,

[0095] k is the compression ratio, which is the ratio of the volume of the coffee powder after being compacted to the volume before being compacted, and is 40%-70%.

[0096] Accordingly, regardless of the actual volume of the coffee powder, the brewing plug calculates the powder compacting stroke when it contacts the coffee powder and actually moves the powder compacting stroke to compact the coffee powder, thereby avoiding powder compacting errors. Then, the water pump 302 works to supply water, and after the water is heated, it flows into the brewing chamber at a certain pressure to brew and extract the coffee powder. When the flow rate of the hot water reaches the set value, the water pump stops supplying water.

[0097] 2.6 As shown in FIG. 2.6, the brewing plug 201 is reset to the initial position, which is determined by a position switch or by allowing the motor to drive the screw rod to rotate in the reverse direction for the total number of turns corresponding to the idle stroke and the powder compacting stroke. The top rod 102 is raised, and the powder cake 402 is lifted and ejected from the brewing chamber. Figure 10

[0098] 2.7 As shown in FIG. 2.7, the brewing chamber 101 is shifted from the powder compacting and brewing position to the powder receiving position. During the shifting process, the powder cake 402 is blocked by the shell 103 and falls. Figure 11

[0099] 2.8 Finally, the brewing chamber 101 is reset to the powder receiving position, and the top rod 102 is lowered to the lowest position of the brewing chamber, so that the next powder receiving, powder compacting, and brewing can be performed.

[0100] ​​In this embodiment, since the coffee beans are ground into coffee powder of different fineness by the coffee bean grinder, and the coffee powder of different fineness has different compression ratio after being compacted, the k value is associated with the fineness of the coffee powder, the k value is larger when the coffee powder is coarser, and the k value is smaller when the coffee powder is finer. Moreover, the fineness of the coffee powder is determined by the adjustment knob adjusting the coffee bean grinder, that is, when the fineness of the coffee powder is adjusted by the adjustment knob adjusting the coffee bean grinder, the k value should change with the fineness of the coffee powder to adapt to the fineness of the coffee powder, and different k values are given for each gear. Therefore, in step 2.5, the k value corresponding to the gear is determined by the controller 304 according to the gear signal transmitted by the detector 303, and a more accurate powder compression stroke is finally determined.

[0101] In Embodiment 1 and Embodiment 2, as shown in Figures 7-8 The top of the coffee powder may present an uneven state with a raised central part, so that when the brewing plug initially contacts the coffee powder, the raised part of the coffee powder will be flattened, and the travel of the brewing plug to flatten the raised part of the coffee powder is not the actual powder compression stroke. In order to accurately determine the powder compression stroke, the process can be corrected. Since the diameter of the brewing chamber is determined, the shape and capacity of the raised part can also be determined, that is, the flattening stroke of the brewing plug to flatten the raised part can be determined. Therefore, as for Embodiment 1, the correction method is to subtract the flattening stroke from the set stroke of Embodiment 1. In Embodiment 2, the powder compression stroke is subtracted from the flattening stroke, that is, ΔL-L1, L1 is the distance of the flattening stroke.

Claims

1. A coffee machine tamping method, characterized by: The capacity of coffee powder (401) in the brewing chamber (101) is determined by the movement of the brewing plug (201) from its initial position to the brewing chamber (101) by a set stroke to compact the coffee powder in the brewing chamber. After brewing, the brewing plug (201) returns to its initial position. The set travel includes an idle travel and a tamping travel, and the following steps are performed: (1) Empty stroke: The brewing plug (201) moves from its initial position toward the brewing chamber (101) until it contacts the coffee powder (401), and the distance of the empty stroke and the volume of coffee powder in the brewing chamber are determined. (2) Tamp stroke: The tamp stroke begins when the brewing stopper (201) contacts the coffee grounds. The brewing stopper (201) continues to move to compact the coffee grounds. (3) Reset stroke: After brewing, the brewing plug (201) is reset to the initial position; in: △L=(L-L0)*(1-k), △L is the distance of the powder pressing stroke. L is the distance between the bottom surface of the brewing stopper and the bottom surface of the brewing chamber when the brewing stopper is in its initial position. L0 is the distance of the empty trip. (L-L0) represents the depth corresponding to the volume of coffee grounds before compaction. k is the compression ratio, which is the ratio of the volume of coffee powder after compaction to the volume before compaction, and is a constant.

2. The coffee machine tamping method according to claim 1, characterized in that: The amount of coffee powder in the brewing chamber (101) is selected on the coffee machine (300).

3. The coffee machine tamping method according to claim 2, characterized in that: For the selected coffee powder volume, the set stroke is a constant.

4. The coffee tamping method according to claim 3, characterized in that: The set travel distance is related to the coarseness of the coffee powder; the set travel distance is smaller when the coffee powder is coarser and larger when the coffee powder is finer.

5. The coffee tamping method according to claim 1, characterized in that: The value of k is 40%-70%.

6. The coffee tamping method according to claim 5, characterized in that: The k value is related to the coarseness of the coffee powder; the k value is larger when the coffee powder is coarser and smaller when the coffee powder is finer.

7. The coffee tamping method according to claim 4 or 6, characterized in that: The coarseness of the coffee grounds is determined by adjusting the grinding mechanism using a knob.

8. The coffee tamping method according to claim 1, characterized in that: The pressure sensor (210) senses the contact between the brewing plug (201) and the coffee powder.

9. The coffee tamping method according to claim 1, characterized in that: brewing... The plug (201) is configured to move from its initial position to the brewing chamber and reset via a threaded drive mechanism driven by a motor (202) via a speed change mechanism (203). The powder pressing stroke is determined by the number of revolutions of the shaft of the motor or the speed change mechanism.

10. The coffee tamping method according to claim 1, characterized in that: The initial position is determined by a position switch.

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