JPH0698099B2 - Electric coffee kettle - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an electric coffee brewer used for general household or business use.

2. Description of the Related Art A conventional drip type electric coffee brewer has a structure as shown in FIG. That is, in FIG. 6, 1 is a heating device having a heater 2 and a heating pipe 3 formed of a stainless pipe or the like built therein, and 4 is a water tank having an outlet 5 at the bottom. 6 is the heating pipe 3
Is a connection tube that connects the outflow port 5 and the outflow port 5, and the outflow port 5 is provided with a convex portion 7 inside thereof, and a check valve 8
It is held with a margin of vertical movement of mm. When the check valve 8 moves upward, the flat surface portion 9 presses the convex portion 7 to keep the watertightness. Conversely, when the check valve 8 moves downward, a gap is generated between the convex portion 7 and the flat surface portion 9 to release the water tightness. Reference numeral 10 denotes an inverted conical basket which is engaged with and held by the main body 11 and which is open at the upper side, and a drip hole 12 is provided at the bottom of the basket 10. Reference numeral 13 denotes a glass container that is placed on the heating device 1 and that is located below the basket 10 to store the extracted coffee. The glass container 13 has a glass container lid 14 having a through hole 15 at substantially the center thereof.
Is placed. Reference numeral 16 is a discharge port having one end opened above the basket 10 and the other end communicating with the heating pipe 3 via a water rising pipe 17.

Reference numeral 18 is a anti-bottling valve that has a valve 19 at one end, a projecting portion 20 projecting downward at the other end, extends, and is supported by the center to rotate. Reference numeral 21 is a pressing spring, and the pressing spring 21 is configured to urge the anti-bottomole valve 18 counterclockwise so that the valve 19 always closes the drip hole 12. Then, when the glass container 13 is set, the projection 20 is pushed by the glass container lid 14, and the anti-bottling valve 18 is rotated clockwise to open the drip hole 12. 22 is an automatic temperature controller that controls the temperature of the heating device 1, 23 is a paper filter housed in the basket 10, and 24 is coffee grounds.

In such a configuration, when water is put in the water tank 4 and the heater 2 of the heating device 1 is energized, the heating pipe 3 is heated to boil the water inside, thereby generating steam, and The expanding force pushes the hot water. Here, the check valve 8 maintains its watertightness because the flat surface portion 9 thereof is pressed against the convex portion 7 side by the force that the hot water due to the expansion force of the steam tries to flow back to the water tank 4. Therefore, due to the expansive force of the steam, the hot water in the heating pipe 3 will be on the side of the rising pipe 17, that is, the discharge port 16.
It will be pushed to the side and will be released above the basket 10. Then, when the hot water in the heating pipe 3 is pushed out from the discharge port 16 by the vapor pressure, the inside of the heating pipe 3 returns to the same pressure as the atmospheric pressure. At this time, the check valve 8 moves downward due to the water pressure of the water tank 4, the plane portion 9 of the check valve 8 separates from the convex portion 7 to release the watertightness, and the check valve 8 flows from the water tank 4 to the heating pipe 3 via the outlet 5. Water flows in. Then, the water flowing into the heating pipe 3 is heated by the heater 2 and boils, and steam is generated, and the expansion force and the function of the check valve 8 cause the hot water to be diffused above the basket 10 from the discharge port 16. In this case, the above operation is repeated until the water in the water tank 4 is exhausted.

The hot water discharged to the basket 10 passes through the coffee grounds 24 to extract the coffee liquid, and the drip hole 12 is used to prevent the leak prevention valve 18
It passes through the through hole 15 of the glass container lid 14 via the and is housed in the glass container 13. When the water in the water tank 4 is exhausted, the heating device 1 is temperature-controlled by the automatic temperature controller 22 and kept at a constant temperature, and the glass container 13 is heated from the bottom to keep the coffee warm.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the conventional electric coffee brewer described above, as shown in FIG. 4, the hot water is diffused to the coffee powder 24 at intervals of several seconds like a geyser (in the figure, Arrow A), and even though the amount of hot water diffused into the basket 10 is almost constant, the water level in the basket 10 is constant because the water permeation rate varies depending on the particle size and amount of the coffee powder 24. No (B and B'in FIG. 4).

Generally, a good extraction method of coffee is shown in FIG. 5 when it is expressed by the pouring amount and the water level in the basket. That is, set the paper filter in the basket, store the coffee grounds, pour dozens of cc of hot water into it by hand (C in the figure), and after about 30 seconds, pour it all at once near the top of the paper filter (D in the figure). Then, when the water level further drops by several cm (E in the figure), the operation of pouring hot water to return to the previous water level (F in the figure) is repeated to pour the predetermined amount.

As described above, the conventional electric coffee kettle is remarkably different from the delicious coffee extraction method, and it has been generally said that coffee brewed with the electric coffee kettle is not delicious.

In view of the above-mentioned conventional problems, the present invention eliminates intermittent injection of hot water, and the water level in the basket at the time of extraction is different depending on the particle size and amount of coffee powder, which results in different hot water permeation rates and extraction components. It is possible to always obtain delicious coffee with constant quality by eliminating the problem that variations occur in the coffee, pouring hot water into the basket at a stretch, and keeping the water level in the basket constant during coffee extraction to eliminate variations in the extracted components. The purpose is to provide an electric coffee brewer capable of.

Means for Solving the Problems To solve the above problems, the present invention provides a hot water storage device, a basket, a hot water supply device that communicates with the hot water storage device to supply hot water into the basket, and measures the weight of the basket. And a control unit that controls the hot water supply device based on information from the weight detection unit.

Operation According to the above configuration, the amount of coffee powder set in the basket is detected by the weight detection unit to determine the hot water supply amount, the amount of hot water in the basket is also detected by the weight detection unit, and based on that information. Since the hot water supply device is controlled by the control unit, it is possible to perform a drip equivalent to a person making coffee by hand, which makes it possible to obtain delicious coffee.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. In the figure, 31 is a base made of phenolic resin or the like. Reference numeral 32 denotes a heating device which contains a heater 33 and a heating pipe 34 and is made of an aluminum alloy. The heating device 32 is held inside the right side of the base 31. Reference numeral 35 denotes a tank which is formed of a heat-resistant synthetic resin and constitutes a hot water storage device. The tank 35 has an opening at the top and an outlet 36 provided at the bottom, and is erected on the upper left side of the base 31. ing. Reference numeral 37 denotes an inverted L-shaped body made of synthetic resin or the like, which is erected on the upper right portion of the base 31. 38
Is an electric pump that constitutes the hot water supply system.
Has a water supply capacity of about 50 cc per second, and has one end communicated with the outflow port 36 of the tank 35 and the other end communicated with a discharge port 40 through a water rising pipe 39. The pumping direction of the pump 38 is from the outlet 36 side to the outlet 40 side. Reference numeral 41 denotes a weight detecting portion, which is formed of a piezoelectric element or a strain gauge, is attached to the locking portion 42, and is fixed to the upper portion of the main body 37. Reference numeral 43 denotes a basket formed of synthetic resin in an inverted conical shape and opening upward.
43 has a mounting portion 44 extending from one of the upper ends thereof, and a hooking portion 45 and a handle 46 extending from the other. Reference numeral 47 is a protrusion extending from the main body 37, and the protrusion 47 is engaged with the hooking portion 45 of the basket 43 and is placed thereon.

Reference numeral 48 is a circulation outlet provided at the bottom of the tank 35, and 49 is a circulation inlet also provided at the bottom of the tank 35. The circulation outlet 48 is provided with a convex portion 50, and the check valve 51 is held on the convex portion 50 with a margin of vertical movement of several mm. When the check valve 51 moves upward, its flat surface
52 presses the convex portion 50 to maintain the watertightness, and conversely, when the check valve 51 moves downward, a gap is generated between the convex portion 50 and the flat portion 52 to release the watertightness. The circulation outlet 48 is an L-shaped tube
It communicates with one end of the heating pipe 34 via 53, and the circulation inlet 49 communicates with the other end of the heating pipe 34.
Reference numeral 54 denotes a temperature detecting portion which is heat-sensitively mounted in the heating device 32 near the heating pipe 34 near the circulation outlet 48 of the tank 35, and is formed of a thermistor or the like.

FIG. 3 shows a block diagram of an electric circuit. The signal of the temperature detection unit 54 is A / D converted by the first A / D conversion circuit 55 and is a control unit composed of a microcomputer or the like. Enter the control circuit 56. The signal of the weight detection unit 41 is the second A /
A / D conversion is performed by the D conversion circuit 57 and the control circuit 56 is entered. Inside the control circuit 56, these temperature and weight data are calculated, and a signal is sent to the heater drive circuit 58 to drive the heater circuit 59, and a signal is also sent to the pump drive circuit 60 to send the pump circuit 61. To drive.

Reference numeral 62 is a spillage prevention valve, 63 is a heat insulating plate that contacts the upper part of the heating device 32, and the heat insulating plate 63 is formed of an aluminum plate. Reference numeral 64 denotes a glass container placed on the heat insulating plate 63 and positioned below the basket 43. The glass container 64 has a through hole 65 in the center and is made of synthetic resin or the like. Is placed. 67 is a paper filter housed inside the basket 43, and 68 is coffee grounds.

In the electric coffee brewer configured as described above,
Next, the operation will be described. Set the paper filter 67 in the basket 43, put a desired amount of coffee powder 68, hold the handle 46, and place the placing portion 44 through the weight detecting portion 41 and the engaging portion 42.
The basket 43 is placed on top, and then the hooking portion 45 is placed on the protrusion 47 to complete the setting of the basket 43.

Next, the tank 35 is filled with water and the heater 33 is energized. The heating device 32 heats the water in the heating pipe 34 to generate steam. At this time, the check valve 51 is pressed by the expansion force of the steam, and the flat portion 52 thereof comes into contact with the convex portion 50 in a watertight manner. Therefore, the hot water in the heating pipe 34 is jetted into the tank 35 from the circulation inlet 49 by the expansion force of the steam. Next, when the expansion force of the steam disappears, the check valve 51 is pushed down by the water pressure in the tank 35, and the watertightness of the flat portion 52 and the convex portion 50 is released. As a result, the water in the tank 35 flows from the circulation outlet 48 to L
It flows into the heating pipe 34 through the shaped tube 53. Then, the water in the heating pipe 34 is heated again by the heating device 32 to generate steam, and the expansion force circulates the water from the circulation inlet 49 into the tank 35. By repeating this, the water temperature in the tank 35 rises and becomes hot water. At this time, the temperature in the vicinity of the heating pipe 34 close to the circulation outlet 48 of the heating device 32 follows the temperature of the inflowing water, so that the temperature of the water is indirectly detected by the temperature detection unit 54 that is mounted thermally. Can be detected.

Then, the signal of the temperature detection unit 54 enters the control circuit 56 via the first A / D conversion circuit 55. On the other hand, as mentioned above, the basket
Since 43 is locked by the protrusion 47 and the hook 45, the weight detector 41 attached to the hook 45 generates a signal proportional to the weight of the entire basket 43. This signal is the second A /
It enters the control circuit 56 via the D conversion circuit 57. And control circuit 5
Within 6, the operation of the pump 38 is determined by the signal from the temperature detection unit 54. That is, when the temperature of the hot water in the tank 35 reaches about 95 ° C., the hot water supply operation is started. First, several tens of cc of hot water is poured by the drive of the pump 38 and stopped for about 30 seconds. On the other hand, the coffee powder in the basket 43 is sent by the signal from the weight detection unit 41.
The weight of 68 is calculated by the following formula.

W = V-B-P-K W: Weight of coffee grounds V: Weight detected weight B: Weight of basket P: Weight of paper filter (about 1g) K: Push-up force by anti-bottomole valve Calculated from the above formula Pump 38 by weight of coffee grounds 68
Calculate the drive time of. Since the driving time of the pump 38 is considered to be proportional to the water supply amount, hot water proportional to the weight of the coffee powder 68 is poured into the coffee powder 68 in the basket 43. In addition, the weight detection unit 41 continuously detects the weight of the basket 43 during the driving of the pump 38, and the basket 43
When the hot water is supplied to a certain level inside, the control circuit 56 judges the signal of the weight detection unit 41 to stop the driving of the pump 38, and when the amount of hot water in the basket 43 decreases to a certain amount, the signal of the weight detection unit 41 is controlled. The circuit 56 judges and the hot water is supplied to the original water level by the pump 38. With this hot water supply, the basket 43
When the hot water is supplied to a certain water level of, the drive of the pump 38 is stopped, and the water level of the basket 43 is lowered by several cm, that is, when the weight of the basket 43 reaches a certain weight, the weight detection unit 41 detects this weight, The pump 38 is driven again to supply hot water to a certain water level. By repeating this, the amount of water initially calculated is supplied and the operation is stopped. This operation is illustrated in Fig. 5, which is the very hand of freshly brewed coffee that is said to be delicious.

Although the piezoelectric element or the strain gauge is used for the weight detection unit 41 in the above-described embodiment, a mechanism in which the capacitance changes depending on the weight may be used for the weight detection unit 41, and a difference occurs in the action and effect. Absent. Further, a mechanism may be used for the weight detection unit 41, in which the basket 43 is hung on a spring and its displacement is detected by a light source and a light receiving unit such as a phototransistor.

Further, in the above embodiment, the heating device 32 and the check valve 51 are provided.
Although the means for obtaining hot water by forming the circulation outlet 48, the circulation inlet 49, and the like has been described, a hot water storage tank may be provided and the hot water in this tank may be supplied by the pump 38. It is a thing.

EFFECTS OF THE INVENTION As is clear from the description of the above embodiments, the electric coffee brewer of the present invention includes a hot water storage device, a basket, a hot water supply device that communicates with the hot water storage device to supply hot water into the basket, and the basket. Since it is composed of a weight detection unit that measures the weight of the coffee and a control unit that controls the hot water supply device based on the information of the weight detection unit, people who are generally said to make delicious coffee can use it. Hot water can be supplied in the same manner as pouring hot water and drip it, which makes it possible to obtain delicious coffee.

[Brief description of drawings]

1 and 2 are sectional views of an electric coffee brewer showing an embodiment of the present invention, and FIG. 3 is a block diagram showing a signal flow in an electric circuit of the electric coffee brewer, and FIG. Is a diagram showing the water level and pouring amount in the basket of the conventional electric coffee brewer, and FIG. 5 is the water level and pouring amount in the basket when a person drips by hand, and when drip in one embodiment of the present invention. FIG. 6 is a sectional view of a conventional electric coffee brewer showing the amount of hot water. 35 …… tank (hot water storage device), 38 …… pump (hot water supply device), 41 …… weight detection unit, 43 …… basket, 56 …… control circuit (control unit).

Claims (1)

[Claims] 1. A hot water storage device, a basket, a hot water supply device which communicates with the hot water storage device to supply hot water into the basket, a weight detection unit for measuring the weight of the basket, and information based on the weight detection unit. An electric coffee brewer constituted by a control unit for controlling the hot water supply device.