Coffee maker

Abstract

To provide a coffee maker capable of raising a temperature of coffee powder before coffee extraction.SOLUTION: A coffee maker includes: a first tank for storing water; a second tank for storing water supplied from the first tank; a water sending part for sending water from the first tank to the second tank; a heater attached to the second tank; a dripper for extracting coffee; a steam path for sending steam from the second tank to the dripper; a start determination part for determining whether or not coffee extraction is to be started; a first water sending execution part for executing water sending to the second tank from the first tank, when determined that coffee extraction is to be started by the start determination part; and a first heating execution part for executing heating by the heater until at least a temperature of water stored in the second tank agrees with a boiling point or higher, when executing water sending of a first water quantity to the second tank by the first water sending execution part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This technology relates to a coffee maker that extracts coffee by pouring hot water into a dripper.

Background Art

[0002] A coffee maker that extracts coffee by pouring hot water into a dripper has been proposed. The coffee maker heats the water in the tank until just before boiling to make hot water, pours the first amount of hot water into the dripper, and steams the coffee powder in the dripper. Then, the second amount of hot water is poured into the dripper to extract coffee. By ensuring sufficient steaming time, the taste of the coffee is improved.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Steaming the coffee powder is preferably performed with hot water at a temperature close to 90°C in order to increase the concentration of the extracted coffee. For example, a coffee maker installed in the kitchen cools down in the morning. Also, water may remain in the path through which the hot water flows. Therefore, when the user first activates the coffee maker in the morning, there is a possibility that cold hot water is first supplied to the coffee powder during the steaming operation.

[0005] This disclosure has been made in view of such circumstances, and an object thereof is to provide a coffee maker capable of raising the temperature of the coffee powder before coffee extraction.

Means for Solving the Problems

[0006] A coffee maker according to one embodiment of the present disclosure includes a first tank for storing water, a second tank for storing water supplied from the first tank, a water supply unit for supplying water from the first tank to the second tank, a heater attached to the second tank, a dripper for extracting coffee, a steam passage for supplying steam from the second tank to the dripper, a start determination unit for determining whether or not to start coffee extraction, a first water supply execution unit for supplying water from the first tank to the second tank if the start determination unit determines to start coffee extraction, and a first heating execution unit for heating the water stored in the second tank with the heater until the temperature of the water is at least above the boiling point if the first water supply execution unit has supplied a first amount of water to the second tank.

[0007] In the coffee maker according to this disclosure, before coffee extraction, the second tank is heated to above its boiling point, and steam is sent from the second tank to the dripper via a steam passage. The temperature of the coffee grounds in the dripper rises.

[0008] A coffee maker according to one embodiment of the present disclosure includes a first water supply execution unit that supplies a first amount of water from the first tank to the second tank, a hot water supply passage that supplies hot water from the second tank to the dripper, an on-off valve interposed in the hot water supply passage, and a first on-off execution unit that opens the on-off valve when the heating of the heater is completed by the first heating execution unit, and closes it after a predetermined time has elapsed.

[0009] In the coffee maker described herein, water heated to its boiling point is supplied to the dripper. The coffee grounds in the dripper, warmed by steam, are steeped in water at nearly 90°C, making it easier to extract a highly concentrated coffee.

[0010] A coffee maker according to one embodiment of the present disclosure includes: a second water supply execution unit which, when the first on / off execution unit opens or closes the on / off valve, supplies a second amount of water from the first tank to the second tank that is different from the first amount of water; a second heating execution unit which, when the first on / off execution unit opens or closes the on / off valve, supplies the water stored in the second tank to the heater until the temperature of the water reaches an extraction temperature that is lower than the boiling point; and a second on / off execution unit which, when the heating of the heater is finished by the second heating execution unit, opens the on / off valve and closes it after a predetermined time has elapsed.

[0011] In the coffee maker according to this disclosure, after the opening and closing of the on / off valve is performed, that is, after the start of the coffee grounds blooming, a second volume of water is sent from the first tank to the second tank, the second tank is heated to at least the extraction temperature, and the hot water is supplied to the dripper. The blooming time of the coffee grounds, the time of sending the second volume of water, and the heating time are overlapped to shorten the time it takes to make coffee. Furthermore, by using water at an extraction temperature lower than the boiling point, it is possible to extract coffee with less bitterness.

[0012] A coffee maker according to one embodiment of the present disclosure includes a progress determination unit that determines whether or not a brewing time has elapsed since the opening and closing of the opening and closing valve was performed by the first opening and closing execution unit, and the second opening and closing execution unit performs the opening and closing of the opening and closing valve when the heating of the heater has been completed by the second heating execution unit and the progress determination unit has determined that the brewing time has elapsed.

[0013] In the coffee maker described herein, after steeping the coffee grounds, coffee is extracted using hot water at the extraction temperature, making it possible to extract coffee with high concentration and less bitterness.

[0014] A coffee maker according to one embodiment of the present disclosure includes a receiving section positioned above the dripper to receive hot water supplied from the second tank, the receiving section having a first hot water passage that penetrates vertically and a second hot water passage that penetrates vertically and is positioned higher than the first hot water passage.

[0015] In the coffee maker according to this disclosure, when the amount or flow rate of hot water supplied from the on-off valve to the receiving section is reduced, hot water is poured into the dripper from the first hot water hole, and when the amount or flow rate of hot water supplied from the on-off valve to the receiving section is increased, hot water is poured into the dripper from both the first and second hot water holes. In other words, the use or non-use of the second hot water hole can be selected.

[0016] In one embodiment of the present disclosure, the coffee maker is mounted on the outside of the second tank.

[0017] In the coffee maker relating to this disclosure, the heater is mounted on the outside of the second tank, which makes it more hygienic than when the heater is mounted on the inside of the second tank. [Effects of the Invention]

[0018] In a coffee maker according to one embodiment of the present disclosure, before coffee extraction, the second tank is heated to a boiling point or higher, and steam is sent from the second tank to the dripper via a steam passage. Therefore, the temperature of the coffee grounds in the dripper can be raised before coffee extraction. [Brief explanation of the drawing]

[0019] [Figure 1] This is a schematic right side view of a coffee maker according to Embodiment 1. [Figure 2] This is a schematic front view showing the second tank, the first solenoid valve, the second solenoid valve, and the dripper, etc. [Figure 3] This is a simplified perspective view of the receiving part. [Figure 4] This is a schematic plan view of the receiving section. [Figure 5] Figure 4 is a schematic cross-sectional view with the VV line as the cutting line. [Figure 6] This is a block diagram of the control unit, control device, heater, etc. [Figure 7] This is a flowchart illustrating the drive process of a coffee maker controlled by a control device. [Figure 8] It is a plan view schematically showing the positional relationship among a dripper, coffee powder, and a central region. [Figure 9] It is a flowchart for explaining drive processing of a coffee maker by a control device according to Embodiment 2.

Embodiments for Carrying Out the Invention

[0020] (Embodiment 1) Hereinafter, the present invention will be described based on the drawings showing a coffee maker according to Embodiment 1. In the following description, the up-down, front-back, left-right shown in the drawings are used. "Coffee" indicates extracted liquid coffee, and "coffee powder" indicates powder obtained by grinding coffee beans. FIG. 1 is a schematic right side view of the coffee maker, and FIG. 2 is a schematic front view showing a second tank 2, a first electromagnetic valve 11, a second electromagnetic valve 16, a dripper 7, etc. The coffee maker includes a first tank 1 for storing water and a second tank 2 for storing water supplied from the first tank 1. The second tank 2 has smaller vertical dimensions and a smaller capacity than the first tank 1. The second tank 2 is arranged on the front side above the first tank 1. The first tank 1 is made of a synthetic resin member. The first tank 1 has a main body 1a having an opening formed on the upper side and an upper lid 1b capable of opening and closing the opening. A user can open the upper lid 1b and put water into the first tank 1.

[0021] The second tank 2 is made of, for example, a metal member. The second tank 2 has a main body 2a having an opening formed on the upper side and an upper lid 2b. The upper lid 2b is screwed to the main body 2a of the second tank 2 to close the opening. The first tank 1 and the second tank 2 are connected by a water supply pipe 18. One end of the water supply pipe 18 is connected to the bottom surface of the first tank 1, and the other end of the water supply pipe 18 is connected to the upper lid 2b of the second tank 2. An electric pump 3 is provided in the middle of the water supply pipe 18. Water is supplied from the first tank 1 to the second tank 2 by the electric pump 3. The electric pump 3 constitutes a water supply unit. A check valve 19 for preventing backflow from the second tank 2 to the first tank 1 is provided in the water supply pipe 18.

[0022] Alternatively, the first tank 1 may be positioned above the second tank 2, and a solenoid valve may be installed in the water supply pipe 18 instead of the electric pump 3. By opening the solenoid valve, water is supplied from the first tank 1 to the second tank 2. In this case, the solenoid valve constitutes the water supply unit.

[0023] A heater 5 is attached to the outer bottom surface of the second tank 2. A temperature sensor 4 is attached to the second tank 2. The temperature sensor 4 penetrates the top lid 2b of the second tank 2 and extends toward the bottom surface of the second tank 2. A gap is provided between the lower end of the temperature sensor 4 and the bottom surface. The heater 5 may also be attached to the outer surface of the second tank 2.

[0024] A dripper 7 is detachably mounted on the lower side of the second tank 2. The second tank 2 and the dripper 7 are separated by a predetermined distance in the vertical direction. The dripper 7 is made of, for example, a metal or resin material. A receiving section 8 is positioned above the dripper 7 to receive the hot water supplied from the second tank 2. The receiving section 8 is a flat, bottomed cylindrical or dish-shaped structure with an open top. A lid 9 is provided above the receiving section 8. The lid 9 closes the opening of the receiving section 8. Details of the configuration of the receiving section 8 will be described later.

[0025] A first hot water supply passage 10 is provided between the receiving section 8 and the second tank 2 in the vertical direction. One end of the first hot water supply passage 10 is connected to the bottom surface of the second tank 2, and the other end is connected to the lid 9 of the receiving section 8. The first hot water supply passage 10 is designed so that hot water flows from top to bottom, i.e., from the second tank 2 to the receiving section 8, due to the action of gravity. A first solenoid valve 11 is interposed in the middle of the first hot water supply passage 10. By opening the first solenoid valve 11, hot water is supplied from the second tank 2 to the receiving section 8. The first solenoid valve 11 is an on / off valve that can be fully open or fully closed. The first solenoid valve 11 constitutes an on / off valve.

[0026] A steam passage 6 is provided between the upper lid 2b of the second tank 2 and the lid 9 of the receiving section 8. Steam generated in the second tank 2 moves to the receiving section 8 through the steam passage 6. A shut-off valve may be provided in the steam passage 6.

[0027] A tray 12 is provided below the dripper 7. In the vertical direction, the dripper 7 and the tray 12 are separated by a predetermined distance. A mesh cover 13 is provided above the tray 12. A container for storing coffee, such as a cup, can be placed on the cover 13. That is, the user can place a cup between the dripper 7 and the cover 13 in the vertical direction and collect the coffee extracted from the dripper 7 in the cup.

[0028] A second hot water supply passage 15 is provided between the cover 13 and the second tank 2 in the vertical direction. One end of the second hot water supply passage 15 is connected to the bottom surface of the second tank 2, and the other end is positioned at a predetermined distance above the cover 13. The other end of the second hot water supply passage 15 constitutes a spout. The spout is positioned opposite the rear side of the dripper 7 and above the lower end of the dripper 7. In the vertical direction, the spout is positioned between the rear side of the dripper 7 and the cover 13. The second hot water supply passage 15 is designed so that hot water flows from top to bottom due to gravity. A second solenoid valve 16 is interposed in the middle of the second hot water supply passage 15. When a cup is placed on the cover 13, opening the second solenoid valve 16 allows hot water to be supplied directly from the second tank 2 to the cup. That is, the second hot water supply passage 15 does not supply hot water to the dripper 7. The second solenoid valve 16 is an on / off valve that can be fully open or fully closed.

[0029] Figure 3 is a schematic perspective view of the receiving portion 8, Figure 4 is a schematic plan view of the receiving portion 8, and Figure 5 is a schematic cross-sectional view with the VV line shown in Figure 4 as the cutting line. As described above, the receiving portion 8 is a flat, bottomed cylindrical or dish-shaped structure with an open top. The receiving portion 8 has a circular bottom portion 8a and a peripheral wall 8b that is substantially perpendicular to the bottom portion 8a. The peripheral wall 8b is annular in shape and is formed along the entire periphery of the bottom portion 8a. The peripheral wall 8b protrudes in the axial direction. The direction of protrusion of the peripheral wall 8b is upward. Two finger grips 8d are formed on the peripheral wall 8b. The finger grips 8d protrude radially outward from the peripheral wall 8b. Two locking portions 8c that lock onto the lid 9 are formed on the upper edge of the peripheral wall 8b.

[0030] The lid 9 of the receiving part 8 is fixed to the housing (not shown). The user engages the receiving part 8 with the lid 9 by bringing the locking part 8c close to the lid 9 from below, placing their finger on the finger hook 8d, and rotating the receiving part 8 in the forward direction. The receiving part 8 can be removed from the lid 9 by placing a finger on the finger hook 8d and rotating the receiving part 8 in the reverse direction. The user can remove the receiving part 8 from the lid 9, clean it, and reattach it to the lid 9.

[0031] As shown in Figure 4, six mortar-shaped first recesses 81a are formed in the bottom surface 8a. A first through-hole 81 is formed in the center of each first recess 81a, penetrating the bottom surface 8a vertically. The six first through-holes 81 are formed inside the central region 85 of the bottom surface 8a. The central region 85 is, for example, rectangular in plan view, and the four first through-holes 81 are positioned slightly inward from each vertex of the rectangle. Two first through-holes 81 are aligned along the longitudinal direction of the rectangle in the center of the central region 85.

[0032] Outside the central region 85, four frustoconical, upwardly raised protrusions 82a are formed. Each of the four protrusions 82a faces the center of each of the four sides of the central region 85. A mortar-shaped second recess 82b is formed at the upper end of each protrusion 82a. A second through hole 82 is formed at the center of each second recess, penetrating vertically through the bottom surface 8a. As shown in Figure 5, the upper end of the second recess 82b is Δh higher than the upper end of the first recess 81a. In other words, the second through hole 82 is positioned higher than the first through hole 81.

[0033] When the first solenoid valve 11 is open, hot water is supplied from the second tank 2 to the receiving section 8. The flow rate (amount flowing per unit time) through the first solenoid valve 11 exceeds the sum of the flow rates from all the first hot water holes 81 and all the second hot water holes 82. If the opening time of the first solenoid valve 11 is short, that is, if the first solenoid valve 11 is open for the first hour as described later, the highest position of the liquid level of the hot water supplied to the receiving section 8 will be above the upper end of the first recess 81a and below the upper end of the second recess 82b, and the hot water will flow only through the first hot water hole 81. If the opening time of the first solenoid valve 11 is long, that is, if the first solenoid valve 11 is open for the second hour as described later, the highest position of the liquid level of the hot water supplied to the receiving section 8 will be above the upper end of the second recess 82b and below the upper end of the peripheral wall 8b, and the hot water will flow through both the first hot water hole 81 and the second hot water hole 82.

[0034] Figure 6 is a block diagram of the operation unit 21, control device 20, and heater 5, etc. The coffee maker includes the control device 20 and the operation unit 21. The control device 20 includes a control unit 20a, RAM 20b, and storage unit 20c. The control unit 20a includes, for example, a processor such as a CPU, MPU, GPU, or ASIC, or a logic circuit (for example, FPGA). The control unit 20a also includes a timer. RAM 20b temporarily stores information. The storage unit 20c includes a rewritable memory such as an EEPROM, EPROM, or flash memory, or a hard disk. The storage unit 20c pre-stores a control program that controls the operation of the coffee maker, as well as the boiling point, steam supply time, temperature T, extraction temperature T1, and brewing time, which will be described later.

[0035] Furthermore, the memory unit 20c pre-stores the following as the opening time for the first solenoid valve 11: a first time when the highest position of the liquid level of the hot water supplied to the receiving section 8 is above the upper end of the first recess 81a and below the upper end of the second recess 82b when the first solenoid valve 11 is opened; and a second time when the highest position of the liquid level of the hot water supplied to the receiving section 8 is above the upper end of the second recess 82b and below the upper end of the peripheral wall 8b when the first solenoid valve 11 is opened. The second time is longer than the first time. The control unit 20a loads the control program into the RAM 20b and controls the operation of the coffee maker.

[0036] The operation unit 21 includes, for example, switches, buttons, keys, or a touch panel, and accepts user input and outputs the input information to the control device 20. The switches include a start switch. The temperature sensor 4 outputs the temperature of the hot water in the second tank 2 to the control device 20. The control device 20 outputs on / off signals to the heater 5 and the electric pump 3. The control device 20 also outputs open / close signals to the first solenoid valve 11 and the second solenoid valve 16.

[0037] Figure 7 is a flowchart illustrating the drive process of the coffee maker by the control device 20. In the initial state, the heater 5 and electric pump 3 are off, and the first solenoid valve 11 and the second solenoid valve 16 are closed. The dripper 7 is pre-filled with a filter and coffee grounds. The control unit 20a receives a signal from the operation unit 21 and determines whether the start switch has been turned on (S1). The on signal from the start switch includes information about the amount of coffee (water volume) to be produced, for example, information indicating the amount of water for a regular cup or a mug. The amount of water for a mug is greater than the amount of water for a regular cup.

[0038] If the start switch is not turned on (S1: NO), the control unit 20a returns to step S1. If the start switch is turned on (S1: YES), the control unit 20a drives the electric pump 3 for a predetermined time to deliver a first volume of water from the first tank 1 to the second tank 2 (S2). After driving for the predetermined time, the electric pump 3 stops. The first volume of water is approximately the same as the amount of hot water used to steep the coffee grounds. The control unit 20a turns on the heater 5 (S3). The timing of turning on the heater 5 may be immediately after starting the water delivery in step S2, or after the delivery of the first volume of water is completed. If an on-off valve is provided in the steam passage 6, the on-off valve is opened at the same time as the heater 5 is turned on.

[0039] The control unit 20a receives the value detected by the temperature sensor 4, i.e., the temperature T of the hot water in the second tank 2, and determines whether the temperature T is above the boiling point (S4). If the temperature T is not above the boiling point (S4: NO), the control unit 20a returns to step S4. If the temperature T is above the boiling point (S4: YES), the control unit 20a determines whether the steam supply time has elapsed since it was determined that the temperature T is above the boiling point (S5). The steam supply time is the time required to supply the steam generated in the second tank 2 to the dripper 7 and the coffee grounds in the dripper 7 via the steam passage 6. The dripper 7 and the coffee grounds are heated by the steam.

[0040] If the steam supply time has not elapsed (S5: NO), the control unit 20a returns to step S5. If the steam supply time has elapsed (S5: YES), the control unit 20a turns off the heater 5 (S6), opens the first solenoid valve 11 for two hours, and then closes it (S7). The second hour in step S7 may differ depending on whether information indicating the amount of hot water for a regular cup has been acquired or whether information indicating the amount of hot water for a mug has been acquired. In either case, the second hour is the time during which the highest position of the liquid level of the hot water supplied to the receiving section 8 is above the upper end of the second recess 82b and below the upper end of the peripheral wall 8b.

[0041] Figure 8 is a plan view illustrating the relative positions of the dripper 7, coffee grounds 70, and central region 85. The hatched areas indicate the area of ​​coffee grounds 70, and the dashed line indicates the central region 85. The upper part of Figure 8 shows the dripper 7 with coffee grounds 70 corresponding to a regular cup size, and the lower part of Figure 8 shows the dripper 7 with coffee grounds 70 corresponding to a mug size. The amount of coffee grounds 70 corresponding to a regular cup size is less than the amount of coffee grounds 70 corresponding to a mug size. The area of ​​the coffee grounds 70 corresponding to a regular cup size is smaller than the area of ​​the coffee grounds 70 corresponding to a mug size.

[0042] As shown in the upper part of Figure 8, the central region 85 overlaps with approximately 80% of the planar area of ​​the coffee grounds 70. As shown in the lower part of Figure 8, the central region 85 overlaps with approximately 50% of the planar area of ​​the coffee grounds 70. In step S7, hot water is supplied from the second tank 2 to the receiving section 8, and the highest position of the liquid level of the hot water supplied to the receiving section 8 is above the upper end of the second recess 82b and below the upper end of the peripheral wall 8b. That is, the hot water flows not only through the first water passage hole 81 located in the central region 85 of the receiving section 8, but also through the second water passage hole 82 located outside the central region 85. Therefore, in both the case of regular cup size and mug size, hot water is supplied to almost the entire planar area of ​​the coffee grounds 70 in the dripper 7, and the entire coffee grounds 70 can be steeped. Regardless of whether the information indicating the amount of hot water included in the ON signal from the start switch in step S1 is for a regular cup or a mug, in step S7, the first solenoid valve 11 is open for two hours, so that the entire amount of coffee grounds 70 can always be steeped.

[0043] The control unit 20a starts timing after the completion of the process in step S7 (S8). The start time of timing is a predetermined time after the completion of the process in step S7. The process in step S8 is for measuring the time it takes to steep the coffee grounds 70, i.e., the steeping time. The control unit 20a drives the electric pump 3 for a predetermined time to deliver a second amount of water from the first tank 1 to the second tank 2 (S9). The second amount of water may be different from or the same as the first amount of water. The second amount of water is approximately the same as the amount of hot water used to extract the coffee. The control unit 20a turns on the heater 5 (S10) and determines whether the temperature T of the water or hot water in the second tank 2 is equal to or greater than the extraction temperature T1 (S11). If the temperature T is not equal to or greater than the extraction temperature T1 (S11: NO), the control unit 20a returns to the process in step S11. The extraction temperature T1 is a temperature lower than the boiling point and is a suitable temperature for extracting coffee with less bitterness. For example, a temperature between 80°C and 90°C.

[0044] If the temperature T is equal to or greater than the extraction temperature T1 (S11: YES), the control unit 20a turns off the heater 5 (S12). After the processing in step S7 is completed, the control unit 20a determines whether the steeping time has elapsed (S13). If the steeping time has not elapsed (S13: NO), the control unit 20a returns to step S13. If the steeping time has elapsed (S13: YES), the control unit 20a ends the timing (S14). The steeping time is longer than the heating time. For example, the steeping time is 60 seconds and the heating time is 20-30 seconds. The steeping time may also be shorter than the heating time.

[0045] The control unit 20a opens the first solenoid valve 11 for one or two hours and then closes it (S15). If information indicating a regular cup size amount of hot water is received, the control unit 20a opens the first solenoid valve 11 for one hour and then closes it. Hot water flows down from the first hot water passage hole 81 to the dripper 7 and is supplied to the central area 85. As shown in the upper diagram of Figure 8, hot water is supplied to the coffee grounds 70 evenly. If information indicating a mug size amount of hot water is received, the control unit 20a opens the first solenoid valve 11 for two hours and then closes it. Note that if information indicating a mug size amount of hot water is received, the second hour in step S15 may be longer or shorter than the second hour in step S7. The second hour in step S15 is the same as the second hour in step S7, which is the time when the highest position of the liquid level of the hot water supplied to the receiving section 8 is above the upper end of the second recess 82b and below the upper end of the peripheral wall 8b. Hot water flows down into the dripper 7 from the first water passage hole 81 and the second water passage hole 82, supplying hot water to the central region 85 and the region outside the central region 85. As shown in the lower diagram of Figure 8, hot water is supplied to the coffee grounds 70 evenly.

[0046] In step S15, if the amount of coffee in the cup does not reach the target amount after one opening and closing operation of the first solenoid valve 11, the opening and closing operation of the first solenoid valve 11 is repeated intermittently multiple times with a predetermined waiting time in between until the target amount is reached. The waiting time is, for example, the time required for almost all of the hot water supplied to the receiving section 8 to be discharged from the receiving section 8. The target amount is about 30-70% of the standard amount for one cup of coffee (for example, 120 ml for a regular-sized cup, or 250 ml for a mug-sized cup). In other words, relatively strong coffee will accumulate in the coffee cup 14.

[0047] The control unit 20a opens the second solenoid valve 16 for a predetermined time, then closes it (S16), supplies hot water to the coffee cup 14, and ends the operation of the coffee maker. In step S16, the predetermined time for opening the second solenoid valve 16 is, for example, the time required to bring the amount of coffee in the coffee cup 14 to a standard amount. For example, it is the time required to supply an amount of hot water that is about 70-30% of the standard amount.

[0048] In the coffee maker according to Embodiment 1, before coffee extraction, the second tank 2 is heated to above its boiling point, and steam is sent from the second tank 2 to the dripper 7 via the steam passage 6. Therefore, the temperature of the coffee grounds 70 in the dripper 7 can be raised before coffee extraction.

[0049] If heating of the second tank 2 is stopped before it boils, convection within the second tank 2 will be insufficient, causing the low-temperature water to accumulate at the bottom of the second tank 2, and making it easier for the low-temperature water to be supplied first from the bottom of the second tank 2. In this embodiment, the second tank 2 is heated to above its boiling point, so sufficient convection occurs within the second tank 2, allowing the high-temperature water to reach the bottom of the second tank 2, and making it easier for the high-temperature water to be supplied from the bottom of the second tank 2 from the beginning.

[0050] Furthermore, since water heated to its boiling point is supplied to the dripper 7, and the coffee grounds 70 inside the dripper 7 are steeped in water at around 100°C or 90°C, it is easier to extract a highly concentrated coffee.

[0051] Furthermore, after the opening and closing of the first solenoid valve 11 (S7), that is, after the start of the blooming of the coffee grounds 70, a second volume of water is sent from the first tank 1 to the second tank 2 (S9), the second tank 2 is heated to the extraction temperature T1, and the hot water is supplied to the dripper 7. By overlapping the blooming time of the coffee grounds 70 with the time for sending the second volume of water and the heating time, the time required to make coffee can be shortened. In addition, by using hot water at an extraction temperature T1 that is lower than the boiling point, it is possible to extract coffee with less bitterness.

[0052] Furthermore, since the coffee grounds (70g) are steeped before brewing with water at extraction temperature T1, it is possible to extract a highly concentrated coffee with minimal bitterness.

[0053] Furthermore, if the opening time of the first solenoid valve 11 is shortened, that is, if the amount of hot water supplied from the first solenoid valve 11 to the receiving section 8 is reduced, hot water is poured into the dripper 7 from the first hot water passage hole 81. If the opening time of the first solenoid valve 11 is lengthened, that is, if the amount of hot water supplied from the first solenoid valve 11 to the receiving section 8 is increased, hot water is poured into the dripper 7 from both the first hot water passage hole 81 and the second hot water passage hole 82. In other words, it is possible to select whether or not to use the second hot water passage hole 82.

[0054] Furthermore, since the heater 5 is installed on the outside of the second tank 2, it is more hygienic than if the heater 5 were installed on the inside of the second tank 2.

[0055] The raised portion 82a and the second water passage hole 82 may be omitted, and the first water passage hole 81 may be formed in the position of the second water passage hole 82. In this case, whether the coffee grounds 70 are being steeped or the coffee is being extracted, hot water is poured onto the coffee grounds 70 from the central region 85 and each of the first water passage holes 81 located outside the central region 85. In steps S7 and S15, the first solenoid valve 11 is opened and closed for a third time when the highest position of the liquid level of the hot water supplied to the receiving portion 8 is above the upper end of the first recess 81a and below the upper end of the peripheral wall 8b.

[0056] (Embodiment 2) The present invention will be described below with reference to drawings showing a coffee maker according to Embodiment 2. In Embodiment 2, components similar to those in Embodiment 1 are denoted by the same reference numerals, and their detailed descriptions are omitted. In Embodiment 1, an on / off valve was used for the first solenoid valve 11, but in Embodiment 2, a flow control valve is used for the first solenoid valve 11 instead of the on / off valve. The opening degree of the first solenoid valve 11 can be changed to alter the flow rate (the amount flowing per unit time).

[0057] The memory unit 20c pre-stores the following opening degrees for the first solenoid valve 11: a first opening degree, where when the first solenoid valve 11 is opened, the highest position of the liquid level of the hot water supplied to the receiving section 8 is above the upper end of the first recess 81a and below the upper end of the second recess 82b; and a second opening degree, where when the first solenoid valve 11 is opened, the highest position of the liquid level of the hot water supplied to the receiving section 8 is above the upper end of the second recess 82b and below the upper end of the peripheral wall 8b. The first opening degree is set so that when a substantially constant flow rate of water flows through the first solenoid valve 11, the flow rate through the first solenoid valve 11 is less than or equal to the sum of the flow rates from all the first hot water holes 81. The second opening is set such that, when a nearly constant flow rate of water flows through the first solenoid valve 11, the flow rate through the first solenoid valve 11 exceeds the sum of the flow rates from all first hot water holes 81, and is less than or equal to the sum of the flow rates from all first hot water holes 81 and all second hot water holes 82.

[0058] When the first solenoid valve 11 is open, hot water is supplied from the second tank 2 to the receiving section 8. When the opening of the first solenoid valve 11 is at the first opening, the highest position of the liquid level of the hot water supplied to the receiving section 8 is above the upper end of the first recess 81a and below the upper end of the second recess 82b, and the hot water flows only through the first hot water passage hole 81. In other words, hot water flows down from the first hot water passage hole 81 to the dripper 7 and is supplied to the central region 85.

[0059] When the first solenoid valve 11 is open to the second degree, the highest position of the water level supplied to the receiving section 8 is above the upper end of the second recess 82b and below the upper end of the peripheral wall 8b, and the water flows through the first water passage hole 81 and the second water passage hole 82. In other words, water flows down from the first water passage hole 81 and the second water passage hole 82 to the dripper 7, and water is supplied to the central region 85 and the region outside the central region 85.

[0060] Figure 9 is a flowchart illustrating the drive process of the coffee maker by the control device 20. Of the processes shown in Figure 9, steps S21-S26, S28-S34, and S36 are the same as steps S1-S6, S8-S14, and S16 shown in Figure 7, so a detailed explanation is omitted.

[0061] After turning off the heater 5 in step S26, the control unit 20a opens the first solenoid valve 11 at a second opening degree for a first predetermined time, and then closes it (S27). The first predetermined time is the time required to supply the amount of hot water necessary for the blooming of the coffee grounds 70.

[0062] After the timing is completed in step S34, the control unit 20a opens the first solenoid valve 11 at a first or second opening degree for a second predetermined time, and then closes it (S35). The second predetermined time is the time required for the amount of coffee in the cup to reach the target amount.

[0063] The embodiments disclosed herein should be considered illustrative and not restrictive in all respects. The scope of the present invention is intended to include all modifications within the claims and equivalents thereof. The matters described in each embodiment can be combined with one another. Furthermore, the independent and dependent claims described in the claims can be combined with one another in any combination, regardless of the form of reference. In addition, the claims use a multi-claim format in which claims refer to two or more other claims (multi-claim format), but are not limited thereto. They may also be described using a multi-claim format in which at least one multi-claim refers to another multi-claim (multi-multi-claim format). [Explanation of symbols]

[0064] 1. Tank No. 1 2. Second Tank 3. Electric pump (water supply unit) 4. Temperature Sensor 5 Heater 6 Steam channel 7. Dripper 8 Receiving part 81 1st hot water hole 82 2nd hot water hole 10. First hot water supply line (hot water supply line) 11. First solenoid valve (on / off valve) 15. Second hot water supply channel 16. Second solenoid valve 20 Control device 20a Control Unit

Claims

1. The first tank for storing water, A second tank for storing water supplied from the first tank, A water supply unit that supplies water from the first tank to the second tank, A heater attached to the second tank, A coffee dripper, A steam passage that sends steam from the second tank to the dripper, A start determination unit that determines whether or not to start coffee extraction, If the start determination unit determines that coffee extraction should be started, the first water supply execution unit executes the water supply from the first tank to the second tank, When the first water supply unit supplies a first amount of water to the second tank, the system includes a first heating unit that heats the water stored in the second tank with the heater until the temperature of the water reaches or exceeds the boiling point. The first water supply execution unit performs the supply of a first amount of water from the first tank to the second tank. Hot water is supplied from the second tank to the dripper, and a hot water supply path different from the steam path is used. A shut-off valve interposed in the aforementioned hot water supply line and When the heating of the heater is completed in the first heating unit, the first on / off unit opens the on / off valve and closes it after a predetermined time has elapsed. A coffee maker equipped with [features / features].

2. The steam passage is connected to the top of the second tank, The hot water supply channel is connected to the bottom of the second tank. The coffee maker according to claim 1.

3. When the opening / closing valve is opened or closed by the first opening / closing execution unit, the second water supply execution unit delivers a second amount of water from the first tank to the second tank that is different from the first amount of water, When the opening / closing valve is opened or closed by the first opening / closing execution unit, the second heating execution unit heats the water stored in the second tank with the heater until the temperature of the water reaches an extraction temperature that is lower than the boiling point, When the heating of the heater is completed in the second heating unit, the second on / off unit opens the on / off valve and closes it after a predetermined time has elapsed. A coffee maker according to claim 1 or 2, comprising:

4. The first opening / closing execution unit includes a progress determination unit that determines whether or not a steaming time has elapsed since the opening / closing of the opening / closing valve was performed, The second opening / closing execution unit opens or closes the opening / closing valve when the heating of the heater has finished in the second heating execution unit and the progress determination unit has determined that the steaming time has elapsed. The coffee maker according to claim 3.

5. It is positioned above the dripper and includes a receiving section for receiving hot water supplied from the second tank, A first through-hole, which penetrates vertically, and a second through-hole, which penetrates vertically and is positioned higher than the first through-hole, are formed on the bottom surface of the receiving portion. A coffee maker according to claim 1 or 2.

6. The heater is attached to the outside of the second tank. A coffee maker according to claim 1 or 2.

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