JPH062107B2 - Coffee mill - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a mill mechanism driven by a motor, in particular, to crush coffee beans in a crushing case and sequentially store coffee powder generated by the crushing in a case. The present invention relates to a coffee mill including a mill mechanism adapted to be housed.

[Technical Background of the Invention and Problems Thereof] Conventionally, in this type of coffee mill, the energization time of the motor for driving the mill mechanism, that is, the mill time is controlled by a mechanical or electronic timer. It is configured.
With such a configuration, the time until all the coffee beans in the crushing case are crushed and the time until all the produced coffee grounds are stored in the storage case are the amount of coffee beans to be milled, It varies greatly depending on the type, freshness, roasting state, storage state, etc. Therefore, the user must consider the set time every time the mill time is set by the timer. However, it is actually extremely difficult to set the set time of the timer to the optimum, so that the operation time of the motor is insufficient and coffee beans or coffee grounds are left in the crushing case, and vice versa. There is a problem that the time becomes excessive and wasteful power is consumed.

[Object of the Invention] The present invention has been made in view of the above circumstances, and an object thereof is to reduce a mill time by a mill mechanism configured to sequentially store coffee powder generated in a crushing case in a storage case. The coffee beans or coffee powder can be automatically controlled in the crushing case so that the optimum time can be adjusted according to the amount, type, freshness, roasting state, storage state, etc. of the coffee beans stored in the crushing case. It is possible to eliminate the possibility that the motor is left unattended or the motor is energized for an excessive time to consume useless power, so that anyone can use it extremely easily and properly without requiring any skill. It is an object of the present invention to provide a coffee mill having an effect that automatic control of the mill time can always be performed accurately regardless of the characteristics of the motor.

[Summary of the Invention] In order to achieve the above-mentioned object, the present invention is provided with a mill mechanism that crushes coffee beans in a crushing case and sequentially stores coffee powder generated by the crushing in a storage case. In a coffee maker, a switch means for controlling the on / off of the motor for driving the mill mechanism, a current detector for detecting a load current of the motor, a synchronization means for generating a synchronization signal in response to power-on, and a synchronization signal for the synchronization signal. Initial drive means for driving the motor by turning on the switch means according to the output, storage means for storing the load current of the motor driven by the initial drive means based on the output of the current detector, and mill operation In response to the operation of the start switch, the switch means is turned on to start energizing the motor, and thereafter, the current is detected by the current detector. Based on the fact that the detected current value has a predetermined relationship with the stored current value of the storage means, the switch means is turned off to provide a control means for disconnecting the motor, whereby crushing is performed. When all the coffee beans stored in the case are ground and stored in the storage case, the power supply to the motor is automatically stopped.

[Examples of the Invention] Examples of applying the present invention to a coffee maker will be described below.

The fourth showing the overall structure of the coffee maker and the structure of the main parts
In FIG. 5 and FIG. 5, 1 is a coffee maker body,
A cartridge-type water storage tank 2 is provided on the left side of the drawing, and a heating table 3 is provided on the lower right side. A heater (indicated by reference numeral 27 in FIG. 1) is provided in the heating table 3.
A well-known hot water generating mechanism including a heating pipe (not shown) is provided, and the water in the water storage tank 2 is supplied into the heating pipe to be turned into hot water. Reference numeral 4 denotes a bottle placed on the heating table 3, and 5 denotes a cup-shaped extractor which is a storage case disposed above the bottle 4, and which has a hooking hole portion 6 (see FIG. 5) formed on the outer periphery of the upper end thereof. (See FIG. 5) is inserted into a projecting piece 7 (see FIG. 5) formed in a rising shape on the coffee maker main body 1 so as to be detachably attached thereto. Such an extractor 5
An extraction port 8 is formed at the bottom of the valve, and a valve device 9 for opening and closing the extraction port 8 is provided. When the extractor 5 is attached to the coffee maker main body 1, the valve device 9 comes into contact with the bottle lid 4 a that covers the bottle 4 and is in an open state. Reference numeral 10 denotes a vertical axis type motor arranged in the coffee maker body 1 at the left side of the extractor 5 in the drawing, and a case mounting portion 11 is formed above the motor 10. Reference numeral 12 is a crushing case detachably attached to the case attaching portion 11. The crushing body 13 rotatably driven by the motor 10 is provided on the inner bottom portion of the crushing case 12, and thus the milling mechanism 14 is constituted by these. A powder filter portion 12a (see FIG. 5) is provided by forming a large number of fine holes on the right side of the crushing case 12,
The powder filter portion 12a faces the upper opening of the extractor 5. Reference numeral 15 is a hood portion for guiding the coffee powder from the powder filter portion 12a into the extractor 5, one end of which surrounds the upper portion and both side portions of the powder filter portion 12a, and the other end portion of which is the upper surface of the extraction portion 5. It extends near the center of the opening. The hood portion 15 is formed in a substantially arcuate shape which is separated from the crushing case 12 toward the lower side, and the tubular hot water receiving portion 1 is provided on the upper surface portion.
6 are integrally formed, and a plurality of pouring holes 17 are formed in the inner area of the hot water receiving portion 16. Reference numeral 18 denotes a lid portion that covers the outer side portion of the hood portion 15 in the upper surface opening portion of the extractor 5, and a cylindrical portion 19 that is inserted into the inner peripheral portion of the upper end of the extractor 5 is integrally formed on the lower surface thereof. There is. Then, the upper end portion of the paper filter 20 housed in the extractor 5 has the extractor 5 and the tubular portion 19
It is sandwiched between and held. The hood portion 15 and the lid portion 18 configured as described above are integrally provided on the crushing case 12. In addition, 21 is the hot water receiving part 1
6 is rotatably provided above 6, and hot water generated by the heating pipe of the hot water generating mechanism is discharged from the hot water supply port body 21 into the hot water receiving portion 16. Reference numeral 22 is a cap detachably attached to the upper surface of the crushing case.

In order to extract the coffee liquid by the coffee maker having such a configuration, first, the coffee beans for the number of people are stored in the crushing case 12, and a predetermined amount of water is stored in the water storage tank 2, and then, as shown in FIG. Set to the state shown. Then, when the motor 10 is energized, the mill mechanism 14 is driven and the crushing of the coffee beans by the crushing body 13, that is, the milling operation is started. As a result, the coffee powder thus generated jumps out of the powder filter portion 12a by centrifugal force when the particle size becomes equal to or smaller than the fine pores of the powder filter portion 12a. The coffee powder that has jumped out is guided by the arc-shaped hood portion 15 while being extracted.
It falls on the paper filter 20 inside. In this case, the hood portion 15 having the function of introducing the coffee powder generated in the crushing case 12 into the extractor 5 has an extremely simple structure and connects the crushing case 12 and the extractor 5 at a substantially shortest distance. Therefore, the amount of coffee powder that adheres to the hood portion 15 and is not recovered in the extractor 5 is small, and the coffee powder recovery rate is high. Further, since the outer portion of the hood portion 15 of the upper surface opening portion of the extractor 5 is covered with the lid portion 18,
Even if the wind generated in the crushing case 12 by the rotation of the crushing body 13 blows into the extractor 5, the wind causes the extractor 5 to move.
The lid 18 prevents the coffee powder inside from being blown out of the extractor 5. After crushing all the coffee beans in this way and then energizing the heater 27 (see FIG. 3) of the hot water generating mechanism, the water in the water storage tank 2 is sequentially turned into hot water, and the hot water supply port body 21 to the hot water receiver 16 It is discharged into the inside of the hood portion 15 from the pouring hole 17 and dropped onto the coffee powder on the paper filter 20. The dropped hot water permeates the coffee powder to extract the coffee extract from the coffee powder, is filtered by the paper filter 20 and is dripped and stored in the bottle 4 from the extraction port 8 as described above. Then, the drip operation is performed.

FIG. 1 shows a circuit configuration of a control device 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. Now, the motor 10 is connected to both ends of the commercial AC power supply 23.
A motor drive switch 24, which is a switch means, is connected in series, and a current transformer 25, which is a current detector for detecting the load current of the motor 10, is interposed in the energizing path of the motor 10. Further, a thermostat 26 for detecting the temperature of the heating table 3, the heater 27, and
A series circuit of a temperature fuse 28 and a heater drive switch 29 is connected. A DC power supply circuit 30 is supplied with power from the power supply 23 through the step-down transformer 31, and power is supplied to each circuit section described below from its output lines La and Lb.

That is, 32 is a differentiating circuit which is a synchronizing means composed of a capacitor 33 and a resistor 34 and which outputs an initialization pulse P ₀ which is a synchronizing means every time the power is turned on. Reference numeral 35 denotes a waveform shaping circuit that shapes the secondary side output waveform of the transformer 31 into a rectangular wave and outputs a synchronization pulse P ₁ synchronized with the power supply frequency. Reference numeral 36 divides the output of the waveform shaping circuit 35 to divide it by 1 Hz, for example. It is a frequency dividing circuit for generating a clock pulse P ₂ . The current transformer 2
The secondary side output of 5 is a diode 37, a capacitor 38,
It is supplied to a current detection circuit 41 including a sampling resistor 39 and an A / D converter 40, and the current detection circuit 41 outputs a digital value detection signal Sa indicating the load current of the motor 10. . A motor drive circuit 42 turns on the motor drive switch 24 when a "1" signal is input, and turns off the motor drive switch 24 when a "0" signal is input.
43 is a heater drive circuit, which turns on the heater drive switch 29 when a "1" signal is input,
When the "0" signal is input, the heater drive switch 29 is turned off. Reference numerals 44 and 45 respectively denote a start switch and a stop switch, which are switches for starting a mill operation provided in the coffee maker main body 1, and when these are turned on, a start pulse P _{3 is} supplied from each.
And the stop pulse P ₄ is output. 46 and 47 are RS flip-flops, 48 to 53 are OR circuits, 54
56 are AND circuits, and 57 are inverters. 58 ~
Reference numeral 60 denotes a transfer gate, which is rendered conductive only when the gate terminal receives the "1" signal, and blocks the passage of the signal when the gate terminal receives the "0" signal. Reference numerals 61 to 63 denote trigger circuits, which respectively output a trigger pulse P ₅ when the input signal rises from “0” to “1”. Reference numeral 64 denotes a delay circuit, which delays the input signal by a slight time (for example, about 0.1 second) and outputs the delayed signal. Reference numerals 65, 66 and 67 are counters, which are transfer gates 58 corresponding to the respective clock terminals CK,
The clock pulse P ₂ input via 59 and 60
And the count value is reset to zero when the input to the reset terminal R rises, and the numerical signals Sm, Sn, So indicating the contents of each count are output from the output terminal Q, respectively. To do. 68-7
Reference numeral 2 is a comparison circuit, which compares the input value to the input terminal A with the input value to the input terminal B, and outputs "1" when A ≧ B.
A signal is output, and a "0" signal is output when A <B. A storage circuit 73 is a storage means that stores the input digital value (the detection signal Sa from the current detection circuit 41 in this case) to the input terminal M only when the trigger pulse P ₅ is applied to the trigger terminal T, and the storage thereof. The numerical signal Sx corresponding to the contents is output from the output terminal Q,
The stored contents are held until the next trigger pulse P ₅ is given. An adder circuit 74 adds the input values to the input terminals X and Y, and outputs the addition result from the output terminal Z as a numerical signal Sz.

Reference numerals 75 to 79 denote constant storage units, in which the constants described below are stored. That is, as in the present embodiment, when the above-described milling operation is performed by the milling mechanism 14 configured such that the coffee beans in the crushing case 12 are sequentially stored in the extractor 5, the load flowing to the motor 10 is reduced. As shown in FIG. 2, the current once exhibits a maximum value in 0.1 to 0.2 seconds after the start of energization and stabilizes in a steady state after 1 to 2 seconds, and after that, the crushing case 12 is
In the state in which the coffee beans are crushed inside, the coffee beans are gradually reduced as the crushing progresses and the generated coffee beans are sequentially transferred to the extractor 5 (“I” in FIG. 2). (The period indicated by "."), And thereafter, the coffee beans in the crushing case 12 are relatively sharply decreased after they are all crushed (the period indicated by "II" in FIG. 2), and all of the produced coffee grounds are crushed in the crushing case. When it is blown away from the motor 12, in other words, when the motor 10 is in an unloaded state (the unloaded state here refers to an empty state of the crushing case 12), the electric current becomes stable at a constant current value. Of these phenomena, the phenomenon in which the load current once rises to the maximum value after the start of energization of the motor 10 is a phenomenon that occurs even in a general coffee mill because it is due to an inrush current. The phenomenon that the current gradually drops and the phenomenon that it stabilizes to a constant value after it falls relatively sharply thereafter is as follows.
This is a phenomenon characteristically occurring in the mill mechanism 14 according to the present embodiment. The time when the load current of the motor 10 decreases and stabilizes at a constant value (mill operation end time) is the crushing case 1
The amount of coffee beans stored in the container 2 largely changes, and the larger the amount of coffee beans is, the later the load current stabilizes at a constant value. Of course, such a motor 10
The change characteristics of the load current depend on the type of coffee beans, the freshness, the roasted state, and the stored state, not limited to the amount of coffee beans, but in any case, the load current eventually drops to a constant current value. It is something to arrive. Then, the constant storage units 75, 7
In 6 is stored a constant corresponding to, for example, 2 (seconds), which is equal to or longer than the time until the load current of the motor 10 stabilizes in a steady state after the start of energization. Further, the constant storage unit 77 stores a constant corresponding to, for example, 20 (seconds), the constant storage unit 78 stores a constant corresponding to, for example, 2 (seconds), which is a compensation value, and the constant storage unit 79 corrects. A constant corresponding to a current value, for example, 0.1 (ampere) is stored.

Further, in the present embodiment, the frequency dividing circuit 36, the motor drive circuit 42, the RS flip-flop 46, the OR circuits 48, 5
The 3 transfer gate 58, the trigger circuits 61 and 62, the delay circuit 64, the counter 65, the comparison circuit 68, and the constant storage unit 75 constitute the initial drive means 80, and the frequency division circuit 3
6, motor drive circuit 42, RS flip-flop 4
7, OR circuits 49 to 53, AND circuits 54 and 55, inverter 57, transfer gates 59 and 60, trigger circuit 63, counters 66 and 67, comparison circuits 69 to 72, addition circuit 74, and constant storage units 76 to 79. Means 81
Is configured.

Next, the operation of the electrical configuration of FIG. 1 will be described with reference to the timing chart of FIG. It should be noted that FIG. 3 shows the output waveform of each part in FIG. 1. The voltage Va across the resistor 39 (indicating the load current of the motor 10), the differentiation circuit 32, the RS flip-flop 46,
Start switch 44, RS flip-flop 47,
Stop switch 45, comparison circuits 69, 72, 71, O
Each output of the R circuit 53, the AND circuit 56, and the heater 2
The energization periods of 7 are shown in correspondence with the respective reference numerals.
When extracting the coffee liquid, first, the power is turned on before the coffee beans are stored in the crushing case 12. Then, at this power-on time t ₁ , the differentiation circuit 3
2, the initialization pulse P ₀ is output, the initialization pulse P ₀ sets the RS flip-flop 46 and the RS flip-flop 47, and the count contents of the counters 66 and 67 are It is initialized. As a result, the motor drive circuit 42 which has received the “1” signal from the set output terminal Q of the RS flip-flop 46 via the OR circuit 56 is driven by the motor drive switch 24.
In order to turn on the motor, the motor 10 is energized and driven, and accordingly, the mill mechanism 14 is started to be driven in an unloaded state. Further, at this time t ₁ , the trigger circuit 61 receiving the “1” signal from the output terminal Q of the RS flip-flop 46 outputs the trigger pulse P ₅ , so the counter 65 is initialized at the same time. The transfer gate 58, which has received the "1" signal at its gate terminal, is rendered conductive, and the counter 65 starts counting the clock pulse P ₂ from the frequency dividing circuit 36 every _second from the initial state. Therefore, the numerical signal Sm output by the counter 65 corresponds to the elapsed time from the time t ₁ . In this way, at the time t ₂ when 2 seconds have passed after the time t ₁ when the counting operation of the counter 65 was started, in the comparison circuit 68, each input of the input terminals A and B is A = B. (A = 2
(Corresponding to the numerical signal Sm from the counter 65), B = 2
(Constant stored in the constant storage unit 75) becomes "1"
It will output a signal. Then, the "1" signal trigger circuit 62 which receives the now outputs a trigger pulse P _5, the detection signal Sa (motor storage circuit 73 which has received the trigger pulse P ₅ to the trigger terminal T is at time t ₂ (Corresponding to the load current value in the steady state at the time of no load driving of 10) is stored. Thus, the trigger pulse P
₅ is output, the counter 65 which receives the trigger pulse P ₅ at the reset terminal R is initialized, and RS which receives the trigger pulse P ₅ through the delay circuit 64.
It will be reset flip-flop 46 at time t _'2. Therefore, this RS flip-flop 46
"1" to the motor drive circuit 42 according to the reset of the
Since the signal supply is stopped, the motor drive switch 24
Is turned off, and the drive of the motor 10 is stopped. In short, the memory circuit 73 stores the current transformer 25 when the motor 10 is driven in a no-load state and stabilizes in a steady state.
The initial drive means 80 drives the motor 10 when the power is turned on, and the load current in the no-load drive state of the motor 10 is stored in the storage circuit as described above. Motor 1 when stored in 73
0 is automatically stopped by disconnection.

After the driving of the motor 10 is stopped in response to the turning on of the power, the coffee beans are stored in the crushing case 12 and the water is supplied to the water storage tank 2 as described above. Set as shown. Then, after that, when the start switch 44 is turned on at time t 3 in FIG. ₃ , the start pulse P ₃ is output, so that the RS flip-flop 47 is set and “1” is output from the output terminal Q. The signal is output. Therefore, the transfer gate 59 becomes conductive, and the counter 66 causes the frequency dividing circuit 3 to operate.
The clock pulse P ₂ from 6 every 1 _second is counted, and therefore the numerical signal Sn output from the counter 66 corresponds to the elapsed time from the time t ₃ .
The counters 66 and 67 are initialized when the power is turned on as described above.
Even when the "1" signal is output from the S flip-flop 47, it is initialized by receiving the trigger pulse P ₅ from the trigger circuit 63, and in the case of continuously executing the coffee brewing operation, We do not have to turn the power on again each time. In the state where the counter 67 is reset, its output, that is, the numerical signal So is zero. Therefore, in the comparison circuit 71, each input of its input terminals A and B is A <B (A = 0 (counter 6
7 (corresponding to the numerical signal So from 7), B = 2 (constant storage unit 7
8), and the "0" signal is output. At this time, similarly, the output of the counter 66 in the reset state, that is, the numerical value signal Sn is also zero, so that also in the comparison circuit 70, the respective inputs of its input terminals A and B are A <B (A = 0 (numerical value signal). Equivalent to Sn), B = 2
It becomes 0 (a constant stored in the constant storage unit 77) and outputs a "0" signal. Therefore, the OR circuit 5
The "0" signal is output from 2 and the inverter 57 is "1".
The AND circuit 55 outputs the signal and receives the "1" signal and the "1" signal from the RS flip-flop 47 to give the "1" signal to the motor drive circuit 42. Therefore, the motor drive circuit 42 turns on the motor drive switch 24, and accordingly, the motor 10 is energized to start driving the mill mechanism 14.
When the count value of the counter 66 reaches the value corresponding to 2 seconds at time t ₄ when 2 seconds have passed after the start of the milling operation, each input value of the comparison circuit 69 becomes A ≧ B and is “1” from now on.
Since a signal is output, AND that receives this "1" signal
Circuit 54 now allows the signal from comparator circuit 72 to pass. That is, the AND circuit 54 allows the signal from the comparison circuit 72 to pass only when the load current of the motor 10 becomes stable in a steady state after the start of the milling operation according to the driving of the motor 10.

When the milling operation is performed in this manner, the load current of the motor 10 and thus the digital-valued detection signal Sa corresponding to the load current gradually decrease in accordance with the progress of the milling operation. At this time, in the adding circuit 74, the constant storage unit 7 stores the numerical signal Sx (corresponding to the load current value of the motor 10 in the no-load drive state) from the storage circuit 73.
The constant (corresponding to 0.1 ampere) stored in 9 is added, and the addition result is output as a numerical signal Sz. Therefore, when the load current value of the motor 10 decreases as described above, and thus decreases until the detection signal Sa becomes equal to the numerical value signal Sz (time t ₅ ), the respective inputs of the input terminals A and B of the comparison circuit 72 change. Since A ≧ B, the comparison circuit 72 outputs the “1” signal. Then, the "1" signal is the AND circuit 5
4 and is given to the gate terminal of the transfer gate 60, the counter 67 starts counting the clock pulse P ₂ . Such counter 67
When time t ₆ when the count value of reaches the value equivalent to 2 seconds,
The input value of the comparison circuit 71 has a relationship of A ≧ B, and the comparison circuit 71 outputs the “1” signal. Then, the OR circuit 52 outputs a "1" signal and the output of the inverter 57 is inverted to a "0" signal, whereby the AND circuit 55 outputs "0".
Since the signal is output, the motor drive circuit 42 receiving the "0" signal turns off the motor drive switch 24, whereby the motor 10 is cut off and the mill operation is automatically terminated. And at the same time, AND circuit 5
R-S flip-flop 47 and OR to both input terminals of 6
Since each "1" signal from the circuit 52 is given, its A
The heater drive circuit 43 receiving the "1" signal from the ND circuit 56 turns on the heater drive switch 29, and accordingly, the heater 27 is energized to start the drip operation.
After the drip operation is completed, the temperature of the heating table 3 rises and the thermostat 26 is turned off (time t ₇ ),
After that, the heat retaining operation is performed in which the heater 27 is controlled by the thermostat 26.

Incidentally, when the stop switch 45 is turned on at time t ₈ Thereafter, it is output stop pulse P ₄ from now, because the counter 66 and 67 is initialized with R-S flip-flop 47 is reset , Especially R-S
In response to the reset of the flip-flop 47, the AND circuit 5
The output of 6 is inverted to a "0" signal and the heater drive circuit 43 turns off the heater drive switch 29, whereby the heat retention operation is stopped.

If the control means 81 does not operate normally due to noise due to the load current of the motor 10 or the like, it starts from the count operation start time t ₃ of the counter 66 for 20 seconds (with the constant stored in the constant storage unit 77). (Equivalent), each input value of the comparison circuit 70 has a relation of A ≧ B, and a “1” signal is output from the comparison circuit 70.
The signal causes the output of the inverter 57 to be inverted to a "0" signal, whereby the mill operation is automatically terminated and the drip operation is started. Therefore, in this case, the constant storage unit 77 stores a value that is equal to or longer than the time required to crush all the coffee beans corresponding to the maximum mill capacity and store them in the extractor 5 during the mill operation of the mill mechanism 14. It is something that is remembered.

According to the present embodiment described above, when the milling operation is performed by the milling mechanism 14, the motor 10 is driven in the no-load state when the power is turned on before the coffee beans are stored in the crushing case 12. At the same time, the load current value of the motor 10 at this time is stored in the storage circuit 73, and the load current value of the motor 10 during the mill operation has a predetermined relationship with the above-mentioned stored current value (actually, the corrected current value is changed to the stored current value). (When it becomes equal to the value obtained by adding (0.1 ampere)), in other words, when all the coffee beans in the crushing case 12 are crushed and blown off, and the crushing case 12 becomes empty, the mill is automatically milled. Since the operation is terminated, the milling time can be always set to the optimum time regardless of the amount, type, freshness, roasting state, storage state, etc. of coffee beans. Within Or like a conventional coffee beans or ground coffee is left behind, in which risk is eliminated that unnecessary power consumption is mill operation time excessive. Moreover,
In this case, when the load current value of the motor 10 during the milling operation has a predetermined relationship with the stored current value of the storage circuit 73, the milling operation is not immediately terminated but 2 seconds after the above relationship is established. Since the configuration is such that the milling operation is terminated only after the time elapses, the coffee powder generated in the crushing case 12 can be surely blown off to the extractor 5. Of course, since the milling operation is automatically performed only by operating the start switch 44, even a person who is a completely new user can use it very easily without any skill. Further, as described above, when the configuration is such that the mill operation can be ended when the load current value of the motor 10 during the mill operation has a predetermined relationship with the load current value during the no-load drive state stored in advance. The milling operation can be accurately terminated when the crushing case 12 is always emptied regardless of variations in the characteristics of the motor 10.

In the above embodiment, the adder circuit 74 and the constant storage unit 79 are provided as a measure when the load current value of the motor 10 during the mill operation does not drop to the storage current value of the storage circuit 73 due to the fluctuation of the power supply voltage. This is provided to stabilize the operation, but it may be provided as necessary, or a multiplication for multiplying the storage current value of the storage circuit 73 by a predetermined coefficient in place of the adding circuit 74. A circuit may be provided. Further, as described above, the OR gates 51, 52 and the transfer gate 6 provided to surely blow the coffee powder generated in the crushing case 12 to the extractor 5.
0, the counter 67, the comparison circuit 71, and the constant storage unit 78 may be provided as necessary. Further, in this embodiment, in order to suppress the influence of the inrush current when the motor 10 is powered on, the transfer gates 58 and 59, the comparison circuit 68,
69, the constant storage units 75 and 76 are provided,
These need not be provided in particular. In addition, in the above-described embodiment, the storage content of the storage circuit 73 is held until the power is turned on next time, so that when the power is once turned on and the milling operation is repeatedly performed, the accurate milling operation is performed any number of times. However, the storage circuit 73 does not need to hold the stored contents as described above,
Further, in the initial drive means 80, the memory circuit 73 is used for the motor 10
Although the motor 10 is automatically turned off and stopped when the load value is stored, such a function may be provided if necessary. Further, in the above embodiment, the cycle of the clock pulse P ₂ may be advanced in order to perform finer control, or each constant storage unit 75.
It goes without saying that the constants stored in 79 to 79 may be changed appropriately.

In addition, the present invention is not limited to the embodiments described above and shown in the drawings, and may be implemented in various modifications without departing from the scope of the invention, such as being applicable to a coffee mill alone. It is a thing.

[Effects of the Invention] According to the present invention, as is clear from the above description, in a coffee mill having a mill mechanism in which the coffee powder generated in the crushing case is sequentially stored in the storage case, the mill using the mill mechanism is used. The time can be automatically controlled to be the optimum time according to the amount, type, freshness, roasting state, storage state, etc. of the coffee beans stored in the crushing case. There is no risk that coffee beans or coffee grounds will be left behind and that the motor energization time will be too long, resulting in wasted power consumption, so anyone can use it extremely easily and properly without the need for skill. In addition, it has an excellent effect that such automatic control of the mill time can always be performed accurately regardless of the characteristics of the motor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention. FIG. 1 is a block diagram of an electrical configuration, FIG. 2 is a load current change characteristic diagram of a motor, and FIG. Chart for coffee, Fig. 4 is a side view showing the entire coffee maker with a part broken away, Fig. 5
The figure is an exploded perspective view of a main part of the coffee maker. In the figure, 1 is a coffee maker main body, 5 is an extractor (housing case), 10 is a motor, 12 is a crushing case, 14 is a mill mechanism, 24 is a motor drive switch (switch means),
25 is a current transformer (current detector), 27 is a heater, 29 is a heater driving switch, 32 is a differentiating circuit (synchronizing means), 41
Is a current detection circuit, 42 is a motor drive circuit, 43 is a heater drive circuit, 44 is a start switch (mill operation start switch), 45 is a stop switch, and 65, 66, 67.
Is a counter, 73 is a storage circuit (storage means), 80 is an initial drive means, and 81 is a control means.

Claims (5)

[Claims] 1. A mill mechanism for crushing coffee beans in a crushing case and sequentially storing coffee powder generated by the crushing in a storing case, a motor for driving the mill mechanism, and a motor for driving the motor. Switch means for disconnection control, a current detector for detecting a load current of the motor, a synchronization means for generating a synchronization signal in response to power-on, and a switching means when the synchronization signal is output. Initial drive means for turning on the motor to drive the motor, storage means for storing the detected current value of the current detector when the motor is driven by the initial drive means, and operation of a mill operation start switch The switch means is turned on to start energizing the motor, and thereafter the detected current value by the current detector is compared with the stored current value of the storage means. Coffee mill, characterized in that the switch means turns off based on became constant relation and a control means for-energized the motor. 2. The control means is configured to turn off the switch means when the current value detected by the current detector becomes larger than the stored current value of the storage means by a predetermined correction current value. A coffee mill as claimed in claim 1. 3. The control means has a counter for starting the counting operation when the current value detected by the current detector has a predetermined relationship with the stored current value of the storage means, and the count value of this counter is preset. Coffee mill according to claim 1, characterized in that it is arranged to turn off the switch means when the defined compensation value is reached. 4. The storage means is configured such that, once the detected current value is stored, the stored content is held until the next synchronization signal is output. A coffee mill according to item. 5. The initial drive means is configured to stop the electric power cutoff of the motor when the storage means stores the detected current value of the current detector after the motor is driven. The coffee mill according to item 1 above.