JPH0770B2 - Coffee extractor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a drip case in which coffee powder is stored by converting water supplied from a water storage tank into hot water in a heating pipe and pushing up the hot water by boiling pressure. The present invention relates to a coffee extractor adapted to extract a coffee liquid by dropping it inside.

[Technical Background of the Invention and Problems Thereof] In this type of coffee extractor, a heating pipe is provided, the base end side of which communicates with the bottom of the water storage tank and the tip end side of which is located above the drip case. It is general that a heater for heating water in the heating pipe is additionally provided at an intermediate portion of the heating pipe. When the coffee liquid is extracted by such a coffee extractor, the heater is energized while the coffee powder is stored in the drip case and the water is supplied to the water storage tank. When the heater is energized in this way, the water flowing from the water storage tank into the heating pipe is turned into hot water here,
The hot water is pushed up by the boiling pressure and dropped into the drip case from the tip side of the heating pipe, so that all the water in the water storage tank is finally dropped and supplied into the drip case. Is. The hot water thus supplied into the drip case is dropped and stored in the container below the drip case while extracting the coffee extract from the coffee powder while passing through the coffee grounds. Extraction of the liquid is performed.

By the way, in the coffee extractor having the above-mentioned structure, the water supplied from the water storage tank into the heating pipe is sequentially converted into hot water in the heating pipe, and the hot water thus generated is pushed up by the boiling pressure to drip case inside the drip case. Since it is configured to repeat the operation of dripping, the cycle of the repeated dripping operation of the hot water and the extraction time of the coffee liquid depending on the temperature of the water supplied from the water storage tank (to the drip case) Corresponding to the time required from the start of hot water supply to the stop of hot water supply). That is, when the temperature of the water in the water storage tank is high and when the temperature of the water in the water storage tank is low, the time required for the water to reach a boiling state is different. In the above, there occurs a phenomenon that the above-mentioned repeated dropping period of hot water is prolonged and the extraction time is extended.

On the other hand, in order to extract a delicious coffee liquid, it is desirable that the extraction time is always a substantially constant time. However, the conventional coffee extractor has a problem that the extraction time is changed each time the temperature of water supplied to the water storage tank is changed due to a difference in season and the like, and as a result, a delicious coffee is always produced. There was a situation in which the liquid could not be extracted and the taste of coffee was not constant due to the temperature of water.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object of the present invention is to supply a time required from the start of hot water supply to a drip case to the end of the hot water supply into a water storage tank. It is an object of the present invention to provide a coffee extractor which can be kept for a substantially constant time regardless of the temperature of water and can always obtain a delicious coffee liquid with a constant taste.

[Summary of the Invention] In order to achieve the above-mentioned object, the present invention is designed so that water supplied from a water storage tank is made into hot water in a heating pipe, and the hot water is pushed up by boiling pressure and dropped into a drip case. In the coffee extractor, a temperature detecting means for detecting the temperature of the heating pipe is provided, and a changing point detecting means for detecting a time point at which the rate of change of the detected temperature is slowed and outputting a rate of change slowing signal is provided. The output of the heater for producing hot water is controlled to increase as the temperature detected by the temperature detecting means becomes lower at the time when the rate blunting signal is output. The cycle in which the hot water is pushed up by the boiling pressure is made uniform regardless of the temperature of the water in the water storage tank.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows the overall structure of a coffee maker having a mill function and a drip function. In FIG. 2, reference numeral 1 is a mill mechanism in which a cutter 3 is provided in a drip case 2 which also serves as a mill case, and 4 is a motor for driving the mill mechanism 1, and the cutter 3 is energized when energized. It is rotated at high speed. Therefore, when the motor 4 is energized with the coffee beans stored in the drip case 2, the coffee beans are crushed by the cutter 3 to generate coffee powder, which performs a milling operation. A filter 5 is provided on the bottom of the drip case 2 to prevent coffee powder (and coffee beans) from falling. Further, a diffusing plate 6 having a large number of pouring holes 6a is detachably attached to the upper opening of the drip case 2, and a hot water supply port body 7 is horizontally rotated above the diffusing plate 6. It is movably installed.

Reference numeral 8 is a water storage tank to which water used for coffee extraction is supplied, and 9 is a heating plate on which a bottle 10 is placed.
A sheathed heater 11 and, for example, a metal heating pipe 12 are attached to the lower surface of the. In this case, as shown in FIG. 3, the sheathed heater 11 is formed in an arc shape so that the heating plate 9
Is located on the lower edge of the
Reference numeral 12 has an arcuate portion 13 arranged along the inner circumference of the sheath heater 11. The heating pipe 12 is connected at its bottom end to the inside of the water storage tank 8 through a check valve (not shown) at its bottom, and at the tip end thereof is connected to the hot water supply port body 7, and the sheath heater 11 is connected to the heating pipe 12. When energized to generate heat, the water flowing from the water storage tank 8 into the heating pipe 12 is heated in the heating pipe 12 (particularly in the arcuate portion 13) to generate hot water, and the hot water is heated by boiling pressure. Diffusion hole of diffusion plate 6 pushed from hot water supply port body 7
It is supplied dropwise into the drip case 2 via 6a. Then, the hot water thus supplied into the drip case 2 is dropped and stored in the bottle 10 through the filter 5 after extracting the coffee extract from the coffee powder in the process of passing through the coffee powder in the drip case 2. As a result, the coffee liquid is extracted.

By the way, the heating pipe 12 is additionally provided with a temperature sensor 14 as a temperature detecting means including a thermistor. In this case, the temperature sensor 14 is an arc-shaped portion of the heating pipe 12.
Since the temperature sensor 14 is provided at a position near the water storage tank 8 in 13, the temperature of the hot water producing portion of the heating pipe 12 can be detected. Reference numeral 15 denotes an operation panel, which includes a start switch 16, a stop switch 17, and selection switches 18 to 22 that are selectively turned on according to the amount of coffee liquid to be extracted (1 to 5 cups). It is provided.

FIG. 1 shows the configuration of a mill and drip control circuit provided in the coffee maker, which will be described below. However, it goes without saying that the functions of the respective blocks shown in the circuit configuration of FIG. 1 may be obtained by a program of a microcomputer as needed.

The motor 4 and the relay switch 24 are connected in series, and the sheath heater 11 and the triac 25 are connected in series to both ends of the commercial AC power supply 23. 26
Is a constant voltage power supply circuit that is supplied with power from a commercial AC power supply 23 via a step-down transformer 27, and power is supplied to each circuit section described below from its output lines La and Lb.

That is, 28 is a waveform shaping circuit, which shapes the secondary side output waveform of the step-down transformer 27 into a rectangular wave and outputs the synchronizing pulse Ps synchronized with the power supply frequency.
Is given to the pulse generation circuit 29. This pulse generator
The reference numeral 29 has three-phase output terminals φ ₁ , φ ₂ , and φ ₃ , and each output terminal φ ₁ , φ ₂ , and φ ₃ is based on the input synchronizing pulse Ps.
1Hz clock pulse whose phases differ from each other by 120 degrees
P _1, P _2, and outputs P ₃ (see FIG. 5). Reference numeral 30 is, for example, a decimal counter, which is provided so as to count the clock pulse P ₁ of ₁ Hz, and therefore the carry pulse P ₄ (see FIG. 5) is output from the counter 30 in a cycle of 10 seconds. It

Reference numeral 31 is an AD conversion circuit that converts the detection output of the temperature sensor 14 into a digital value, and outputs the conversion value as a temperature signal S ₁ . Reference numeral 32 is a motor drive circuit, which turns on the relay switch 24 to energize the motor 4 when a "1" signal is input, and turns off the relay switch 24 when a "0" signal is input. . Reference numeral 33 is a heater driving circuit, which operates when the "1" signal is input.
Is turned on to energize the sheath heater 11, and when the "0" signal is input, the triac 25 is turned off. 34
Is an output control circuit for adjusting the output of the sheathed heater 11 through the heater driving circuit 33. This is a cycle "1" according to the input heater output data signal (which will be described later). Signal to heater drive circuit 33
Is intermittently turned on to intermittently turn on the triac 25, so that the duty ratio is controlled so that the output of the sheath heater 11 corresponds to the heater output data signal.

35 to 37 are RS flip-flops, 38 is an OR circuit, 39 to 61 are A
ND circuits, 62 to 66 are inverters. 67 to 89 are transfer gates, which are conductive only when the gate terminal receives a "1" signal to allow the passage of signals.
Reference numerals 90 to 93 are trigger circuits, which respectively output a trigger pulse Pt when the input signal rises from "0" to "1".

94 is a counter for measuring time, which uses the clock pulse P ₁ given to the clock terminal CK as a timing element, outputs each count content as a numerical signal S ₂ , and when the input to the clear terminal CL rises. Is configured to initialize the count content. Reference numerals 95 to 99 denote storage circuits. Among them, the storage circuits 95 to 98 sequentially update and store the data whenever the corresponding transfer gates 67, 68, 69, 71 are turned on and new data is input. Is configured. Further, the storage circuit 99 initializes the stored contents when the input to the clear terminal CL rises and stores the input numerical value to the input terminal I at that time when the input to the preset terminal PR rises. And outputs the stored contents as a numerical signal S ₃ from the output terminal Q. 100 to 106 are comparison circuits,
These compare each input to input terminals A and B, and A> B
In the case of, the "1" signal is output, and in the case of A≤B, the "0" signal is output. 107 and 108 are subtraction circuits, which subtract the input numerical value for the input terminal D from the input numerical value for the input terminal C and output the subtraction results as numerical signals S ₄ and S ₅ , respectively. 109 is a constant multiplication circuit, which is the storage circuit 9
The numerical signal S ₃ from 9 is multiplied by a predetermined constant, for example, “0.5”, and the multiplication result is output as the numerical signal S ₇ .

Here, in each case where the start switch 16 and the stop switch 17 are turned on, the start pulse Pa and the stop pulse Pb composed of the "1" signal are output respectively, and the selection switches 18 to 22 are also provided. When is turned on, the selection pulse Pc that also consists of the "1" signal from each
Is output. Reference numeral 110 denotes an extraction amount setting circuit provided so that the input terminals I _{1 to} I ₅ receive the selection pulses Pc from the selection switches 18 to 22, and when the selection pulse Pc is input, the selection pulse Pc is input. It is configured to latch the state of outputs "1" signal from the output terminal Q ₁ to Q ₅ that corresponds to the input terminal I ₁ ~I ₅ which is given.

Reference numeral 111 denotes a constant storage unit that stores constants for determining the mill operation time by the mill mechanism 1. In this case, the above constants are actually selected according to the amount of coffee beans to be supplied to the mill. Although it is possible to appropriately change and set it by an external operation means (not shown), it is assumed that a constant of, for example, 12 (seconds) is stored in this embodiment for convenience of explanation. Reference numeral 112 denotes a constant storage unit that stores constants necessary for ending the drying operation in the heating pipe 12 (which will be described later).
A constant of, for example, 150 (° C.) corresponding to the temperature detected by the temperature sensor 14 when the water inside 12 which is in an uncooked state is completely evaporated is stored. 113,114,115
Is a constant storage unit that stores constants corresponding to predetermined temperature values for arithmetic processing, and these are, for example, 5 (° C.) and 60, respectively.
Constants corresponding to (℃) and 65 (℃) are stored. 116
Numerals 132 to 132 are constant storage sections for storing predetermined constants given to the output control circuit 34 as heater output data signals. These constant storage sections are, for example, as shown in FIG.
Each constant within the range of 100 (W) to 1000 (W) is stored.

The AND circuit 46, the inverters 65 and 66, the comparison circuit 105,
The detection temperature rank dividing circuit 133 is configured by the 106 and the constant storage units 114 and 115, and is provided with _three output lines L ₁ , L ₂ and L ₃ . Also, AND circuit 4
4, the output holding circuit 134 is configured by the transfer gate 88 and the constant storage unit 132, and the transfer gates 67, 68, 7
0, the trigger circuit 92, the storage circuits 95, 96, 99, the comparison circuits 103, 104 and the constant multiplication circuit 109 constitute the change point detection means 135 in the present invention, and the RS flip-flop 36, the transfer gate 71, the trigger circuit 93 and the storage. The circuit 98 constitutes the temperature measuring circuit 136. Further, 137 is a control means in the present invention, and this control means 137 includes the detection temperature rank dividing circuit 133, the output control circuit 34, and an AND circuit.
43, 45, 47 to 61, transfer gates 72 to 87, 89, and constant storage units 116 to 131.

Next, the operation of the above configuration will be described with reference to FIGS. 4 to 6. In the timing chart of FIG. 4, the temperature TX detected by the temperature sensor 14 (corresponding to the temperature of the hot water producing portion of the heating pipe 12), the output from the set output terminal Q of the RS flip-flop 35, the output of the comparison circuit 101. , AND circuits 40, 41 outputs, storage circuit 99 output terminals Q outputs, RS flip-flops 36, 37 set output terminals Q outputs, AND circuits 44, 45, 43 outputs, sheathed heater 1
Each change state of the output of 1 is shown corresponding to each sign. Further, the timing chart of FIG. 5 shows the respective output timings of the clock pulses P ₁ , P ₂ , P ₃ from the pulse generating circuit 29 and the carry pulse P ₄ from the counter 30, and the temperature characteristics of FIG. In the curve diagram, three types of changing states of the temperature TX detected by the temperature sensor 14 shown in FIG. 4 are shown with the temperature TC of the water in the water storage tank 8 as a parameter.

When extracting the coffee liquid, first, the coffee beans for the number of cups (the number of people) corresponding to the amount of the coffee liquid to be extracted are stored in the drip case 2, and the required amount of water is stored in the water storage tank 8. To supply. At this time, one of the selection switches 18 to 22 corresponding to the number of extraction cups is turned on, and when the selection switch 18 corresponding to "1 cup" is turned on, the extraction amount setting circuit Since the “1” signal is output from the output terminal Q _{1 of the} 110, the AND circuits 47 to 49 receiving this “1” signal in one input terminal are input signals to the other input terminal (line
L ₁ , L ₂ , L ₃ output) is allowed to pass. Also,
When the selection switches 19 to 22 respectively corresponding to "2 cups" to "5 cups" are turned on, the extraction amount setting circuit
Since “1” signals are output from the output terminals Q _{2 to} Q _{5 of the} 110, each group of AND circuits 50 to 52, 53 to 55, 56 to 58, 59 to 61 outputs an input signal to the other input terminal ( Line L ₁ , L ₂ ,
L ₃ output) will be selectively allowed.

Then, when the start switch 16 is turned on at time t ₁ in FIG. 4 thereafter, the RS flip-flop 35 is set by the start pulse Pa output in response thereto, and the RS flip-flops 36, 37 are turned on. The memory contents of the memory circuit 99 are reset and initialized. When the RS flip-flop 35 is set and the "1" signal is output from the set output terminal Q thereof as described above, the trigger circuit 90 receiving the "1" signal outputs the trigger pulse Pt, and the trigger pulse Pt is output. The count content of the counter 94 is initialized by Pt. When the counter 94 is initialized in this way, its output, that is, the numerical signal S ₂ is zero. Therefore, in the comparison circuit 101, the inputs of the input terminals A and B are A <B (A = 0, B = 12 (constant stored in the constant storage unit 111) and the “0” signal is output. As a result, the inverter 62 is connected to one input terminal of the AND circuit 40.
Provides an inverted "1" signal. The other input terminal of the AND circuit 40 is connected to the RS flip-flop 3
Since the "1" signal is supplied from the set output terminal Q of 5, the AND circuit 40 outputs the "1" signal, and the "1" signal is supplied to the motor drive circuit 32. Then, the motor drive circuit 32 causes the relay switch 24
Is turned on, the motor 4 is energized in response to this, and the mill mechanism 1 is driven, whereby the grinding of the coffee beans stored in the drip case 2 is started. Further, when the start switch 16 is turned on, the AND circuit 39 which receives the "1" signal from the RS flip-flop 35 at one input terminal receives the input signal (that is, 1 Hz clock pulse P ₁ ) to the other input terminal. Counter will be allowed to pass
The counter 94 counts up from the initialized state every 1 second, so the count content of the counter 94 (numerical signal S ₂ )
Is the time elapsed since the start switch 16 was turned on,
That is, it indicates the duration of the mill operation. Then, from time t ₁ when the start switch 16 is turned on to time t ₂ when 13 seconds have elapsed, each input to the input terminals A and B of the comparison circuit 101 becomes A> B. 1 "
The signal is output. Then, the output of the AND circuit 40 is "0".
Since the signal is inverted, the relay switch 24 is turned off by the motor drive circuit 32, whereby the motor 4 is cut off and the mill operation is terminated. Also, at this time, for both input terminals of the AND circuit 41, the “1” signal from the RS flip-flop 35 and the “1” signal from the comparison circuit 101 are input.
Since the signal is given, the AND circuit 41 comes to output the "1" signal.

In short, when the start switch 16 is turned on,
Time corresponding to a constant stored in the constant storage unit 111 (this constant can be actually changed by an external operating means as described above) (actually, it is longer than the above storage constant by 1 second) The mill operation of the
The “1” signal output from the AND circuit 41 at t ₂ corresponds to the signal indicating that the mill operation has ended.

When the stop switch 17 is turned on during the mill operation, the stop pulse output by turning it on
Since the RS flip-flop 35 is reset by Pb, the output of the AND circuit 40 is inverted to the “0” signal in response to this, and the motor drive circuit 32 turns off the relay switch 24, resulting in the mill operation. Is stopped on the way.

Thus, the time t ₂ after those drip operation is performed. That is, when "1" signal is output at time t ₂ from the AND circuit 41, the "1" signal is applied to input terminals of the AND circuits 43, 44 and 45. At this time, a 3-input AND circuit 4
In the case of 4, the "0" signals from the set output terminals Q of the RS flip-flops 36 and 37 reset when the start switch 16 is turned on are supplied to the remaining input terminals by the inverters 64 and 63, respectively. Since it is inverted and given to the "1" signal, the "1" signal is outputted and given to the gate terminal of the transfer gate 88. As a result, the transfer gate 88 becomes conductive, so that the constant storage unit
The constant "500 (W)" stored in 132 is given to the output control circuit 34 as a heater output data signal. Then, in the output control circuit 34, the "1" signal is intermittently output at a cycle corresponding to the input constant "500 (W)" to intermittently output the triac 25 via the heater drive circuit 33. Then, the sheath heater 11 is energized while controlling the duty ratio so that its output corresponds to the constant "500 (W)". In this way, the output holding circuit 134 holds the output of the sheathed heater 11 at a constant value (500 W) preset in the constant storage unit 132 at the beginning of energization of the sheathed heater 11. When the sheath heater 11 is energized and heated, the water flowing from the water storage tank 8 into the heating pipe 12 is heated by the arcuate portion 13 to be turned into hot water, and the hot water is pushed up by the boiling pressure to supply hot water. Mouth 7
Will be supplied from the drip case 2
Thus, the drip operation is performed.

By the way, in the coffee maker adopting the hot water supply structure as in the present embodiment, the water from the water storage tank 8 is sequentially turned into hot water in the heating pipe 12, and therefore, depending on whether the temperature of the water in the water storage tank 8 is high or low. The time until the water is turned into hot water will change greatly. That is, in FIG. 6, the time change state of the temperature of the hot water producing portion of the heating pipe 12 (the temperature TX detected by the temperature sensor 14) in the state where the sheathed heater 11 continuously generates heat with a constant output is shown in the water tank 8. The water temperature TC is shown as a parameter (35 ℃, 20 ℃, 5 ℃). In FIG. 6, a ₁ point on the time axis,
b ₁ point, the _point c corresponds to the time the pushes due to the boiling pressure of the generated hot water began (when the hot water supply is started), the detected temperature TX is relatively rapidly increased until the hot water supply start time At the same time, after this, it will drop slightly and settle to a fixed value. Further, in FIG. 6, a ₂ point, b ₂ point, and
Point c ₂ corresponds to the time when the water in the water storage tank 8 is almost turned into hot water and the temperature inside the heating pipe 12 starts to rise sharply (the time when the hot water supply is almost finished), and points A, B, and C on the temperature axis. Point is a ₁ above
It shows the detected temperature TX corresponding to points b ₁ , b ₁ and c ₁ .

As is clear from FIG. 6, the detected temperature TX at the time when hot water supply is started according to the energization of the sheath heater 11 and the time ΔF from the start of hot water supply until the end of hot water supply (corresponding to the required time for hot water supply and thus the extraction time) ) Changes according to the temperature TC of the water in the water storage tank 8. In this case, there is a certain correlation between the detected temperature TX at the start of hot water supply and the temperature TC of the water in the water storage tank 8 that the detected temperature TX becomes lower as the water temperature TC becomes lower. Therefore, the water temperature TC can be indirectly detected based on the detected temperature TX at the start of hot water supply. Since the hot water supply required time ΔF changes depending on the level of the water temperature TC as described above, if the drip operation is executed with the output of the sheathed heater 11 kept constant, the water supplied to the water storage tank 8 may be reduced. Because the extraction time of coffee liquid will change due to the difference in the temperature of
This causes a problem that it is impossible to extract a coffee liquid having a delicious and constant taste. Further, it is desirable that the extraction time does not change much regardless of the extraction amount of the coffee liquid even when the extraction amount of the coffee liquid is different, but in such a case, the water storage tank 8 is naturally used.
Since the amount of water supplied to the inside will be different in magnitude, if the sheath heater 11 is configured to generate heat with a constant output, the hot water supply required time and thus the extraction time will be different, causing the same problems as described above. It will be. Note that in FIG. 6, the detected temperature TX during (each period of _{a 1 ~a 2, b 1 ~b} 2, c 1 ~c 2) hot-water supply period is different depending on the water temperature TC, the temperature sensor 14 Is provided at a position close to the water storage tank 8 in the arcuate portion 13 of the heating pipe 12, and is easily affected by the water temperature TC in the water storage tank 8.

Now, in the present embodiment, the above-mentioned problems are solved as described below.

That is, the transfer gate 67 receives the clock pulse P ₂ output from the pulse generating circuit 29 at a cycle of 1 _second at its gate terminal. Therefore, the transfer gate 67 becomes conductive every 1 second and is output from the AD conversion circuit 31. The temperature signal S ₁ (corresponding to the temperature TX detected by the temperature sensor 14) is passed. Therefore, the memory circuit 95 stores a new detected temperature TX every 1 second.
Are sequentially updated and stored. In addition, the transfer gate 68
The gate terminal receives a clock pulse P ₁ having a cycle of 1 second, which is output from the pulse generation circuit 29 after the clock pulse P ₂ by a time τ (see FIG. 5). The detected temperature TX stored in the storage circuit 95 is passed through while being brought into conduction. Therefore, the detected temperature TX is sequentially updated and stored in the memory circuit 96 of the next stage with a delay of time τ from the memory circuit 95. As a result, in the period corresponding to the delay time τ between the clock pulses P ₂ and P ₁ , the sampling time of each detected temperature TX stored in the storage circuits 95 and 96 has a time difference of 1 second. Then, in the subtraction circuit 108, the input to the input terminal D (the detected temperature TX from the storage circuit 96) is subtracted from the input to the input terminal C (the detected temperature TX from the storage circuit 95), and the subtraction result is the numerical signal S. Output as ₅ . Therefore, the numerical signal S ₅ output during the period corresponding to the delay time τ between the clock pulses P ₂ and P ₁ corresponds to the increase value of the detected temperature TX in 1 second, and this numerical signal S ₅ Are applied to the input terminal A of the comparison circuit 103, the input terminal B of the comparison circuit 104, and the input terminal I of the storage circuit 99.

Since the memory circuit 99 is initialized at the time t ₁ , it initially stores a value of zero, and the numerical signal S ₃ corresponding to the stored value is output from the output terminal Q to the comparator circuit.
It is given to the input terminal B of 103. At this time, the detected temperature TX rises after the time t ₂ when the energization of the sheath heater 11 is started, so that the respective inputs to the input terminals A and B of the comparison circuit 103 are always in the relation of A> B. Comparison circuit
The “1” signal is output from 103. Then, "1" above
The trigger circuit 92 that receives the signal outputs the trigger pulse Pt and applies it to the preset terminal PR of the memory circuit 99, so that the memory circuit 99 newly stores the numerical signal S ₅ at that time. . Then, even after that, during the period when the detected temperature TX is rising, the trigger circuit
The trigger pulse Pt is output from 92, and the storage operation of the new numerical signal S ₅ is repeated in the storage circuit 99. That is, the memory circuit 99 newly stores the numerical value signal S ₅ only when the numerical value signal S ₅ larger than the currently stored value is input, and as a result, the numerical value output from the memory circuit 99. The signal S ₃ comes to correspond to the maximum rise value of the detected temperature TX for one second until the output time point.

The numerical signal S ₅ from the storage circuit 99 is supplied to the constant multiplication circuit 10
It is multiplied by "0.5" by 9 and converted into a numerical signal S ₆ ,
This numerical signal S ₆ is applied to the input terminal A of the comparison circuit 104. The output of the comparison circuit 104 is the transfer gate 7
Although it passes 0, the gate terminal of the transfer gate 70 is output from the pulse generating circuit 29 at a period of 1 second in a period corresponding to the delay time τ between the clock pulses P ₂ and P _1. Clock pulse P ₃ (see FIG. 5) is applied. Therefore, the comparison operation of the comparison circuit 104 is performed during the period in which the transfer gate 70 is in the conductive state by the clock pulse P ₃ , that is, the subtraction circuit.
Only when the numerical signal S ₅ output from 108 corresponds to the increase value of the detected temperature TX in one second, the signal is validated. Then, when the numerical signals S ₅ and S ₆ have a relationship of S ₆ > S _{5 in} the period in which the comparison operation of the comparison circuit 104 is enabled in this way, in other words, at time t in FIG. _{In 3} , heating water is started to be pushed up by the boiling pressure in the heating pipe 12 (hot water supply), and the rate of change of the detected temperature TX (gradient of temperature increase) is slowed down. 1 of the detected temperature TX whose rise value is stored in the memory circuit 99
When it becomes 1/2 or less of the maximum rise value in a second,
The comparison circuit 104 has a rate-of-change slowing signal S composed of a "1" signal.
_It outputs ₀ . In this way, the changing point detecting means 135 detects a time point at which the rate of change of the temperature TX detected by the temperature sensor 14 becomes slow (time at which hot water supply is started), and outputs the rate of change slowing signal S _0. . At this time, since the transfer gate 70 is in the conductive state as described above, the rate-of-change blunting signal S ₀ passes through the transfer gate 70 and is given to the set input terminal S of the RS flip-flop 36. Sets the RS flip-flop 36. In FIG. 4, the rate of change of the detected temperature TX is negative at time t _3, but this is related to the mounting position of the temperature sensor 14, and the temperature sensor 14 is attached to the heating pipe 12. When it is located near the center of the arcuate portion 13, the influence of the temperature TC of the water in the water storage tank 8 decreases and the degree of blunting of the rate of change of the detected temperature TX at time t ₃ decreases. The constant in the constant multiplication circuit 109 is set.

At time t ₃ , when the rate-of-change blunting signal S ₀ is output and the RS flip-flop 36 is set as described above, the trigger circuit which receives the “1” signal from the set output terminal Q thereof
Since the trigger pulse Pt is output from 93, the transfer gate 71 is rendered conductive by the trigger pulse Pt. Then, the detected temperature TX stored in the storage circuit 95 passes through the transfer gate 71 and is stored in the storage circuit 98. In this way, the temperature measuring circuit 136 measures the detected temperature TX at the time when the rate-of-change blunting signal S ₀ is output (at the time when hot water supply is started) and stores the measurement result in the memory circuit 98. is there. In this case, as described above, there is a certain correlation between the detected temperature TX at the time when hot water supply is started and the temperature TC of the water in the water storage tank 8 that the detected temperature TX becomes lower as the water temperature TC becomes lower. Therefore, the detected temperature TX stored in the storage circuit 98 corresponds to the water temperature TC,
As a result, the temperature measuring circuit 136 indirectly detects the water temperature TC in the water storage tank 8.

Further, at the time t ₃ , when the “1” signal is output from the RS flip-flop 36, the “1” signal is inverted to the “0” signal by the inverter 64 and the AND circuit 44.
Therefore, the output of the AND circuit 44 is inverted to the "0" signal, and the transfer gate 88 which has been in the conductive state until then is switched to the cutoff state. At the same time, the "1" signal from the AND circuit 41, the "1" signal from the inverter 63, and the "1" signal from the RS flip-flop 36 are supplied to the respective input terminals of the 3-input AND circuit 45. Since it is supplied, its output is inverted into a "1" signal, and the transfer gate 89 receiving the "1" signal at its gate terminal is rendered conductive. As a result, the constants stored in the constant storage units 116 to 130 can be selectively input to the output control circuit 34 as heater output data signals.

On the other hand, as described above, when any one of the selection switches 18 to 22 corresponding to the number of extraction cups is turned on, the AND circuits 47 to 49, 50 to 52, 53 to 55, 56 to 58 corresponding to each ON state. , 59 ~ 6
Any one of the groups ₁ is in a state in which the output of the lines L ₁ , L ₂ , and L ₃ (output from the detected temperature rank dividing circuit 133) is allowed to pass. Therefore, when extracting one cup of coffee liquid, the constant storage unit 11 is used as the heater output data signal.
Any one of the constants stored in the groups of 6 to 118 will be selectively used, and similarly, in each case of extracting 2 to 5 cups of coffee liquid, the heater output is used. As the data signal, the constant storage units 119 to 121, 122 to 124,
Any one of the constants stored in the groups 125 to 127 and 128 to 130 will be selectively used. Then, the selection of a constant from each group of the constant storage units 116 to 130 is performed based on the output of the detected temperature rank dividing circuit 133 which receives the output from the temperature measuring circuit 136, as described below.

That is, the detected temperature TX stored in the storage circuit 98 at the time t ₃ has the property of becoming longer as the temperature TC of the water in the water storage tank 8 becomes lower. It is given to each input terminal A as a comparison input. In this case, when the detected temperature TX stored in the storage circuit 98 is 60 ° C. or less (that is, the water temperature TC is relatively low), the inputs of the input terminals A and B in the comparison circuit 105 are A ≦ B (B Is the constant “60” stored in the constant storage unit 114.
Is given) and a "0" signal is output, and in the comparison circuit 106, each input of the input terminals A and B is A.
<B (the constant “65” stored in the constant storage unit 115 is given to B) and the “0” signal is output, and accordingly, the lines L ₁ , L ₂ , and L ₃ Of these, the “1” signal is output only to the line L ₁ . In addition, in the state where the detected temperature TX exceeds 60 ° C and is 65 ° C or less (the state where the water temperature TC is medium),
Since the comparison circuit 105 outputs the “1” signal and the comparison circuit 106 outputs the “0” signal, the “1” signal is output only to the line L ₂ . Furthermore, the detected temperature TX exceeds 65 ° C (water temperature TC is relatively high)
In order to "1" signal is output from both the comparator circuits 105 and 106, "1" signal is to be outputted only to the line L _3.

Therefore, when the detected temperature TX at the time of starting hot water supply has a relationship of TX ≦ 60 ° C., the AND circuits 47, 50, 53, 56, 59 from the line L ₁
Since the "1" signal is given to the transfer amount setting circuit 110, the "1" signal is output from any one of the AND circuits 47, 50, 53, 56, 59 according to the output state from the extraction amount setting circuit 110, and the transfer One of the gates 72, 75, 78, 81, 84 corresponding to the AND circuit is in a conductive state. When the relation of 60 ° C. <TX ≦ 65 ° C., the “1” signal is given from the line L ₂ to the AND circuits 48, 51, 54, 57, 60, so that the output state from the extraction amount setting circuit 110 is changed. Accordingly, one of the AND circuits 48, 51, 54, 57, 60 outputs a "1" signal, and one of the transfer gates 73, 76, 79, 82, 85 corresponding to the AND circuit is Shows continuity. Further, when the relationship of 65 ° C. <TX is satisfied, the “1” signal is given from the line L ₃ to the AND circuits 49, 52, 55, 58, 61, so that the above-mentioned condition is output depending on the output state from the extraction amount setting circuit 110 A "1" signal is output from any one of the AND circuits 49, 52, 55, 58, 61 to transfer gates 74, 77,
One of the 80, 83, and 86 corresponding to the AND circuit is in the conductive state.

As described above, depending on the number of extraction cups selected by the extraction amount setting circuit 110 and the level of the detected temperature TX at the start of hot water supply (and thus the level of the temperature TC of the water in the water storage tank 8), the transfer gates 72 to One of the 86 is in a conductive state, which allows the constant storage units 116-130.
The constant stored in any of the above is given as a heater output data signal to the output control circuit 34 via the transfer gate 89 which is in the conductive state at the time t ₃ as described above. Then, in the output control circuit 34, the duty ratio is controlled so that the output of the sheathed heater 11 becomes a value according to the constant input as described above, whereby the output of the sheathed heater 11 is stored in the water storage tank 8. It changes according to the temperature TC of the water and the amount of coffee extracted. In this case, the storage constants of the constant storage units 116 to 130 are output according to the storage constants and the sheath heater is used.
A value is stored in advance so that the hot water supply time required when 11 is heated becomes substantially constant regardless of the temperature TC of the water in the water storage tank 8 and the amount of extracted coffee liquid. That is, as the above memory constants, the higher the temperature measured by the temperature measuring circuit 136, in other words, the lower the temperature TC of the water in the water storage tank 8 indicated by the detected temperature TX at the start of hot water supply, the seeds. A value is stored such that the output of the sheathed heater 11 is increased as the output of the heater 11 is increased and the amount of discharged coffee liquid is increased, whereby the time t _{3 to} t ₄ is stored.
The required time for hot water supply, and thus the extraction time, is made constant regardless of the temperature TC of the water in the water storage tank 8 and the amount of extracted coffee liquid.

In this way, the output of the sheath heater 11 is controlled by the control means 137.
The drip operation is performed in a state adjusted by, and when the water in the water storage tank 8 is consumed in accordance with the progress of such drip operation and there is almost no water flowing into the heating pipe 12, The temperature TX detected by the sensor 14 suddenly rises. In this case, the transfer gate 69 receives the carry pulse P ₄ output from the counter 30 in a cycle of 10 seconds at its gate terminal and passes the detected temperature TX from the memory circuit 95 every 10 seconds. TX is sequentially updated and stored in the memory circuit 97. Therefore, the subtraction circuit
In the case of 107, the input to the input terminal C (memory circuit 95
From the current detected temperature TX) to the input to the input terminal D (detected temperature TX from the memory circuit 97 at a time point 10 seconds before), and the subtraction result is output as a numerical signal S ₄ . Therefore, this numerical signal S ₄ corresponds to the rise value of the detected temperature TX in 10 seconds, and this numerical signal S ₄ is compared with the storage constant (5 ° C.) of the constant storage unit 113 in the comparison circuit 102. It Then, as described above, since the water in the heating pipe 12 almost disappears, the drip operation is ended and the detected temperature TX rapidly rises, so that at time t ₄ , the temperature rise value per 10 seconds is 5 ° C.
When it exceeds, the comparison circuit 102 outputs a "1" signal to the AND circuit 42. The "1" signal is applied to the other input terminal of the AND circuit 42 from the set output terminal Q of the RS flip-flop 36, and therefore the time t ₄
Then, the trigger pulse Pt is output from the trigger circuit 91 which receives the "1" signal from the AND circuit 42, and the trigger pulse Pt is output.
RS flip-flop 37 is set by Pt. Then, the output of the AND circuit 45, which has been outputting the "1" signal until then, is inverted to the "0" signal, the transfer gate 89 is cut off, and the output of the AND circuit 43 is inverted to the "1" signal. Then, the transfer gate 87 becomes conductive. Therefore, after the time t ₄ when the drip operation is finished, the constant (100 (w)) stored in the constant storage unit 131 is supplied to the output control circuit 34, and the sheath heater 11 is set to 100 W. Drying operation that heat is generated at the output is performed, so that the water remaining in the heating pipe 12 is gently evaporated, and the generation of unpleasant odor and rust due to the remaining water is prevented in advance. . Further, during the drying operation after the end of the drip operation, the sheath heater 11 generates heat due to a relatively low output of 100 W, and as a result, a small amount of water remaining in the heating pipe 12 evaporates rapidly, and A large amount of high-heat steam is not jetted from 7, and the risk of burns or the like due to the jetted steam is prevented in advance.

Then, at time t ₅ thereafter, when the detected temperature TX indicated by the temperature signal S ₁ exceeds the temperature 150 ° C. for finishing the drying operation stored in the constant storage unit 112, the comparison circuit 1
The respective inputs to the input terminals A and B of 00 have a relation of A> B, and the "1" signal is output from now on. Then, the RS flip-flop 35 is reset and the output of the AND circuit 41 is inverted to the "0" signal, and in response to this, the output of the AND circuit 43 which has been outputting the "1" signal until then is also the "0" signal. Therefore, the transfer gate 87 is switched to the cutoff state, and in response thereto, the input of the heater output data signal to the output control circuit 34 is stopped, whereby the sheath heater 11 is cut off and the drying operation is ended. It

Further, during the drip operation and the drying operation, when the stop switch 17 is turned on, the RS flip-flop 35 is reset by the stop pulse Pb output in response to the turning on, and the AND circuit 41 is also responded thereto.
The output of is inverted to the "0" signal and the AND circuits 43,44,45 block the passage of the signal.
87, 88, 89 are held in the cut-off state, the sheath heater 11 is cut off, and the drip operation and the drying operation are stopped halfway.

According to the present embodiment described above, the time required for hot water supply, that is, the extraction time of the coffee liquid becomes a preset substantially constant time regardless of the water temperature TC in the water storage tank 8, so that it is delicious and always has a constant taste. Can extract coffee liquor.
Further, in the above embodiment, the detected temperature at the time when hot water supply is started
Since the hot water supply required time is determined based on TX, there is an advantage that the hot water supply required time is constant even if the rating of the sheathed heater 11 varies or the power supply voltage changes. Further, according to the present embodiment, the heating pipe 12 is provided so as to detect the temperature of the hot water producing portion.
Since the temperature TC of the water in the water storage tank 8 is also indirectly detected by utilizing the individual temperature sensors 14, the entire structure can be simplified.

In the above embodiment, the temperature measured by the temperature measuring circuit 136 is divided into three ranks by the detected temperature rank dividing circuit 133. However, the temperature may be divided into multiple ranks, and the extraction amount setting circuit 110 also has five ranks. It is not limited to the stage setting. Further, in the above embodiment, the temperature sensor 14 is provided at a position near the water storage tank 8 in the arcuate portion 13 of the heating pipe 12, but it is not always necessary to provide it at such a position. However, when the above configuration is adopted, the temperature TC detected by the temperature sensor 14 is likely to be affected by the water temperature TC in the water storage tank 8. Therefore, at time t ₃ (change rate slowing signal S _{0 in} FIG. 4). Is output and the RS flip-flop 36 is set), the degree of change in the detected temperature TX becomes large, and as a result, the output timing of the rate-of-change blunting signal S ₀ becomes accurate and control of the extraction time is ensured. Has the advantage that Further, it goes without saying that the storage constants of the constant storage units 111 to 132 are not limited to the above-mentioned embodiments. Further, in each of the above embodiments, the sheath heater 11
Although the output of is controlled by duty ratio control, other means such as phase control means may be used.

Besides, the present invention is not limited to the embodiments described above and shown in the drawings. For example, other means may be adopted as the change point detecting means, and various modifications may be made without departing from the scope of the invention. It can be implemented.

EFFECTS OF THE INVENTION According to the present invention, as is clear from the above description, the water supplied from the water storage tank is turned into hot water in the heating pipe, and the hot water is pushed up by the boiling pressure to store the coffee powder. In a coffee extractor configured to extract coffee liquid by dripping in a drip case, the time required from the start of hot water supply to the drip case until the end of the hot water supply is supplied to the water storage tank. It is possible to obtain a coffee liquid that is delicious and always has a constant taste regardless of the temperature of the water being used, variations in the rating of the heater for generating hot water, fluctuations in the power supply voltage, etc. Is something that can be done.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a block diagram of an electrical configuration, FIG. 2 is a side view showing a coffee extractor partially broken, and FIG. 3 is a coffee extractor. Bottom views, FIGS. 4 and 5 are timing charts for explaining the action, and FIG. 6 is a temperature change characteristic diagram for explaining the action. In the figure, 1 is a mill mechanism, 2 is a drip case, 7 is a hot water supply port, 8 is a water storage tank, 11 is a sheath heater, 12 is a heating pipe, 14 is a temperature sensor (temperature detecting means), 16 is a start switch, 17 Is a stop switch, 18 to 22 are selection switches, 34 is an output control circuit, 110 is an extraction amount setting circuit, 133 is a detection temperature rank dividing circuit, 134 is an output holding circuit, 135 is a change point detecting means, and 136 is a temperature measuring circuit. , 137 are control means.

Claims (3)

[Claims] 1. A heating pipe into which water from a water storage tank flows, and a heater for turning the water in the heating pipe into boiling water to push the boiling water up by boiling pressure and supply the drip case into which coffee powder is stored. A temperature detecting means provided to detect the temperature of the heating pipe, and a change point detecting means for detecting a time point at which the rate of change of the temperature detected by the temperature detecting means becomes slow and outputting a rate of change slowing signal. Control means for controlling the output of the heater to increase as the temperature detected by the temperature detecting means decreases at the time when the rate-of-change blunting signal is output. And a coffee extractor. 2. The coffee extractor according to claim 1, wherein the control means is configured to control so that the output of the heater increases as the amount of coffee liquid extracted increases. . 3. The coffee extractor according to claim 1, wherein the temperature detecting means is configured to detect a temperature of a position of the heating pipe near the water storage tank.