JP3496275B2 - coffee maker - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coffee maker for controlling a heating means by judging an amount of water. 2. Description of the Related Art A conventional coffee maker performs a uniform extraction regardless of the amount of water, or a user inputs the number of cups. [0003] However, in the conventional method, there is a problem that the optimum extraction cannot be performed or the user has to input the number of cups, which is inconvenient. . The present invention is intended to solve such a conventional problem, and determines a water amount without being influenced by a power supply voltage or a heater variation from a temperature gradient of a water tank temperature and a gradient of a pipe temperature. It is an object of the present invention to provide a coffee maker having a function of judging the condition. [0005] Means [SUMMARY OF] The present invention for achieving the above object includes a water tank, a pump, a pipe through which water, a switching valve for controlling the water, such as a heater Heating means, time measuring means for measuring time, water tank temperature measuring means for measuring the temperature of the water tank, first temperature gradient measuring means for measuring the temperature gradient of the water tank temperature at the beginning of heating, and the temperature of the pipe Pipe temperature measuring means for measuring the temperature gradient of the pipe temperature, third temperature gradient measuring means for measuring the temperature gradient of the pipe temperature, the second to determine the amount of water from the output of the first temperature gradient measuring means and the third temperature gradient measuring means And a heating control means for controlling the heating means. The means of the present invention has a function of determining the amount of water without being affected by the power supply voltage or the variation in the heater by determining the amount of water from the temperature gradient of the water tank temperature and the gradient of the pipe temperature. It acts as a coffee maker. An embodiment of the present invention will be described with reference to FIGS. First a description will be given of the overall configuration of this reference example with reference to FIG. Figure 1 is a schematic cross-sectional view of the present embodiment. 1 is a bean container for holding coffee beans, 2 is a motor, and a cutter 3
To grind the beans. 4 is a motor control means for controlling the motor. 5 is a mesh filter, 6 is a paper holder, 7 is a water tank, 8 is a thermistor, tank temperature measuring means for measuring the temperature of the water tank 7, 9 is a pump, 10 is a pipe through which water passes, and 11 is water. , A receiving container, 14 a heater, 13 a heater control means for controlling the heater, 15 a time measuring means for measuring time, 20 a first temperature for measuring a temperature gradient of a water tank temperature at the beginning of heating. Temperature gradient measuring means, 21 is a second temperature gradient measuring means for measuring the temperature gradient of the water tank temperature in the middle stage of heating, and 16 is the output of the first temperature gradient measuring means 20 and the second temperature gradient measuring means 21. water is the first water determining means for determining. In this embodiment, the motor control means 4, the heater control means 13, the time keeping means 15, the first temperature slope measurement means 20, the second temperature slope measurement means 21, and the first water amount determination means 16 are constituted by microcomputers. I have. [0008] In the following, for the entire coffee maker of the present embodiment the operation thereof will be described. The user puts a desired amount of beans in the bean container 1 and a desired amount of water in the water tank 7, and turns on a switch (not shown). The coffee beans put into the bean container 1 are ground by a cutter 3 rotated by a motor 2. The motor 2 is controlled by the control means 4. When the particle size of the ground coffee beans becomes large enough to pass through the mesh filter 5, the coffee beans are accumulated in the paper holder 6. Control means 4 and the grinding is completed to stop the motor 2. On the other hand, the water in the water tank 7 is circulated in the pipe 10 by the pump 9. At this time, the circulating water is heated by energization of the heater 14 controlled by the heater control means 13. The temperature of the circulating water has been detected in tank temperature measuring means 8. After the start of heating, first, the first temperature gradient measuring means 20 measures the temperature change of the water tank at the beginning of heating, and then the second temperature gradient measuring means 21 measures the temperature change of the water tank at the middle stage of heating. Is measured. The first water amount determining means 16 determines the amount of water from the outputs of the first temperature gradient measuring means 20 and the second temperature gradient measuring means 21. The temperature of the water rises,
When the output of the tank temperature measuring means 8 reaches a predetermined temperature, the switching valve 11 is operated. That is, the direction of flowing water is switched and water is poured into the bean container 1. At this time, the heater control means 13 controls the energization of the heater 14 in accordance with the amount of water by the first water amount determination means 16. That is, the coffee extraction pattern is performed according to the amount of water. The injected water passes through the paper holder 6 to extract coffee, and then accumulates in the receiving container 12. [0012] Next, a first temperature gradient measuring means 20 of the present reference example, the second temperature gradient measurement unit 21 will be described with reference to FIG. 2 with the operation of the first water determination means 16. FIG. 2 is a schematic diagram showing a time change of the output of the tank temperature measuring means 8 during the mill operation. The solid line in FIG. 2 when water is medium quantity,
The dotted line indicates a small amount, and the dashed line indicates the temperature increase when the amount is large.
As shown in FIG. 2, it takes time for the water tank temperature to start rising from the heater ON. This is because only the water on the heater 14 of the pipe 10 is heated by the heater 14, and the water temperature of the water tank 7 rises after the heated water circulates through the switching valve 11. [0013] The first of the temperature gradient measurement means 20 heater ON
At this time, the output T0 of the tank temperature measuring means 8 is read, and the time dt1 until the output of the tank temperature measuring means 8 becomes T0 + dT is measured using the time measuring means 15. The second temperature gradient measuring means 21 measures the time dt2 required for the water tank temperature to change from T1 to T2 using the time measuring means 15. First water quantity determination means 16 this dt1 and dt
2 is used as an input to determine the amount of water. As can be seen from the figure, dt1 is short when the amount of water is small, and is long when the amount is large. However, since the influence of the power supply voltage and the variation in the performance of the heater is strongly affected, if the water amount is specified only from dt1, the determination accuracy is deteriorated. dt2 is less susceptible to variations in power supply voltage and heater performance than dt1. However, dt2 basically becomes shorter when the amount of water is small, but also becomes shorter when the amount of water is very large. This is because when the water heated by the heater 14 circulates through the switching valve 11, there is a large amount of water in the water tank 7, so that only the upper part is heated without mixing with the lower layer, and the lower remaining water is finally discharged. This is because it is heated at once. Due to such characteristics, the amount of water cannot be determined only from dt2. However, by inputting both dt1 and dt2, the amount of water can be determined. [0015] In this reference example is the first water determination unit 16 d
It is configured by fuzzy inference that takes t1 and dt2 as inputs and outputs the amount of water. The rules of fuzzy inference are: "If dt1 is small and dt2 is small, the amount of water is small.""If dt1 is small and dt2 is large, the amount of water is medium."
1 is large, the smaller the amount of water dt2 is a large amount. "
It consists of four rules: "If dt1 is large and dt2 is large, the amount of water is slightly large". A qualitative concept such as dt1 being “small” or a large amount of water is quantitatively expressed by the membership function shown in FIG. [0016] Thus, according to the present embodiment, it is possible to provide a coffee maker having a function of determining the amount of water from the temperature gradient of the water tank temperature of the heating initial heating medium term water tank temperature. Although an example in which fuzzy inference is used as the first water amount determination means 16 has been described, a method using a neural network or a function may be used. Further, although the triangular type is used as the membership function of the fuzzy inference, a bell type or a real type may be used. An embodiment of the present invention will be described with reference to FIGS. First will be described the overall configuration of the present embodiment with reference to FIG. 17 is configured by a thermistor, the pipe 1
A pipe temperature measuring means for measuring a temperature of 0; a third temperature gradient measuring means for measuring a temperature change of the pipe temperature;
Reference numeral 8 denotes a second water amount determining unit that determines the amount of water from the outputs of the first temperature gradient measuring unit 20 and the third temperature gradient measuring unit 23. In the present embodiment, the third temperature gradient measuring means 23 and the second water amount determining means 18 are constituted by microcomputers. Other configurations are common to the first embodiment of the present invention, and are represented by common numbers in FIG. With the above configuration, the operation is the same as that of the above-mentioned reference example of the present invention. At this time, in this embodiment, the pipe temperature measuring means 17 measures the temperature of the water flowing in the pipe, and the third temperature gradient measuring means is the pipe temperature measuring means 17.
And measuring the temperature change of the water in the pipe from the timer 15. The second water amount determining means 18 determines the amount of water from the outputs of the first temperature gradient measuring means 20 and the third temperature gradient measuring means 23. Next, the operation of the third temperature gradient measuring means 23 and the second water amount determining means 18 of this embodiment will be described with reference to FIG. FIG. 5 shows a pipe temperature measuring means 1 during heating.
7 is a schematic diagram showing the time variation of the output of. The solid line in FIG. 5 shows the change when the wattage of the heater is low, and the dotted line shows the change when the wattage is high. The water in the pipe is heated by the heater 14 and rises in temperature. When the water boils, it is pushed out by the vapor pressure and returns to the water tank 7 through the switching valve 11. Since the pump 9 newly sends the water in the water tank 7 to the pipe 10, the water temperature in the pipe decreases and the water is heated again. By this repetition, the temperature of the water in the water tank 7 gradually rises. Therefore, the pipe temperature repeatedly rises and falls as shown in FIG. 5, and the minimum temperature rises. Here, when the wattage of the heater is different due to the variation of the power supply voltage or the capability of the heater, the cycle of the temperature rise and fall is different as shown by the difference between the solid line and the dotted line in FIG. This cycle is hardly affected by the amount of water stored in the water tank 7. Because the heater 14 heats only the water on the heater 14 in the pipe 10, the water tank 7
This is because a fixed amount of water is heated without being affected by the amount of water in the inside. Therefore, the watt of the heater can be determined from the rate of change of the output of the pipe temperature measuring means 17. In this embodiment, the third temperature gradient measuring means 2
3 measures the temperature rising / falling cycle t using the time counting means 15. The cycle t is obtained, for example, by taking the point at which the temperature changes from rising to falling as a change point and measuring the time between the two change points. The second water amount determining means 18 determines the water amount by using the t and the output dt1 of the first temperature gradient measuring means 20 as inputs. In this embodiment, the second water amount determining means 18 is t
And dt1 as input and output the amount of water by fuzzy inference. Fuzzy inference of the rule has a small "dt1,
If t is small, the amount of water is medium. "" dt1 is small,
If t is large, the amount of water is small. "" dt1 is large,
If t is small, the amount of water is large. "" dt1 is large,
If t is large, the amount of water is medium. " A qualitative concept such as dt1 being “small” or a large amount of water is quantitatively expressed by the membership function shown in FIG. As described above, according to the present embodiment, it is possible to provide a coffee maker having a function of determining a water amount without being affected by a power supply voltage or a heater variation from the temperature gradient of the water tank temperature and the gradient of the pipe temperature. it can. Although an example in which fuzzy inference is used as the second water amount judging means 18 has been described, a method using a neural network or a function may be used. Further, although the triangular type is used as the membership function of the fuzzy inference, a bell type or a real type may be used. As described above, the means of the present invention comprises a water tank, a pump, a pipe through which water passes, a switching valve for controlling water, a heating means such as a heater, and a time measuring device. Timer means for measuring the temperature of the water tank, first temperature gradient measuring means for measuring the temperature gradient of the water tank temperature at the beginning of heating, and pipe temperature measuring means for measuring the temperature of the pipe. A third temperature gradient measuring means for measuring the temperature gradient of the pipe temperature, a second water amount determining means for determining a water amount from the output of the first temperature gradient measuring means and the output of the third temperature gradient measuring means, heating As a coffee maker equipped with a heating control means for controlling the means, a function to determine the water amount without being affected by the power supply voltage or the heater variation from the temperature gradient of the water tank temperature and the gradient of the pipe temperature. Provided device can be realized.

Schematic diagram [shows the chronological variation of the measured values of tank temperature measuring means Reference Example Reference Example of a schematic cross-sectional view of the coffee maker invention; FIG BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1] The present invention (A) dt1 of fuzzy inference of the reference example of the present invention
(B) A diagram showing a membership function of dt2 of the fuzzy inference (c) A diagram showing a membership function of water amount of the fuzzy inference [FIG. 4] A coffee maker according to an embodiment of the present invention. the fuzzy inference embodiment of schematic cross-sectional view Figure 5 is a schematic diagram showing a time variation of the measured value of pipe temperature measurement means embodiment of the present invention [FIG. 6] (a) the present invention dt1
(B) Diagram showing the membership function of t in the fuzzy inference (c) Diagram showing the membership function of the amount of water in the fuzzy inference [Description of Signs] 7 Water tank 8 Tank temperature measuring means 9 Pump 10 Pipe 11 Switching valve 13 Heater control means 14 Heater 15 Clocking means 16 First water amount determination means 17 Pipe temperature measurement means 18 Second water amount determination means 20 First temperature gradient measurement means 21 Second temperature gradient measurement Means 22 First microcomputer 23 Third temperature gradient measuring means 24 Second microcomputer

Continuing on the front page (72) Inventor Kenji Noda 1006 Kadoma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. 72) Inventor Hironobu Tanaka 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-5-137654 (JP, A) JP-A-63-147421 (JP, A) JP-A-63-230122 (JP, A) JP-A-63-102722 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A47J 31/057

Claims (1)

(57) [Claims 1] A water tank, a pump, a pipe through which water passes, a switching valve for controlling water, a heating means such as a heater, a time measuring means for measuring time, Water tank temperature measuring means for measuring the temperature of the water tank, first temperature gradient measuring means for measuring the temperature gradient of the water tank temperature at the beginning of heating, pipe temperature measuring means for measuring the temperature of the pipe, Third temperature gradient measuring means for measuring a temperature gradient, second water amount determining means for determining a water amount from outputs of the first temperature gradient measuring means and the third temperature gradient measuring means, and heating for controlling the heating means A coffee maker comprising control means.