JPH08107826A - Coffee boiler - Google Patents

Abstract

PURPOSE: To detect the completion of grinding of coffee beans with a simple constitution and high accuracy, stop quickly the running of a motor and start the extraction of coffee. CONSTITUTION: The vibrational signals of a grinding chamber 2 and motor 4 are measured by a vibration detecting element 13a and a vibrational wave form processing element 14. If the current value of the motor 4 detected by a current detecting means 15 is at most a predetermined value at the time when a difference between the maximum value and the minimum value per predetermined time is below a predetermined value for a predetermined time, a grinding completion detecting means 16 judges the completion of the grinding to stop the motor 4 and start the extraction of coffee.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coffee brewer equipped with a coffee bean crushing device.

[0002]

2. Description of the Related Art Conventionally, this type of coffee brewer is shown in FIG.
The structure shown in FIG. The configuration will be described below with reference to FIG.

In the drawing, 1 is a commercial AC power source, 2 is a coffee crushing chamber, and 3 is a crushing chamber for crushing coffee beans, the bottom of which is provided with a hole through which crushed coffee grounds pass. The cutter is rotatably provided in the crushing chamber 2. 4 is a motor for rotating the cutter 3. Reference numeral 5 denotes a filtration chamber which is provided below the crushing chamber 2 and in which a paper filter is set and crushed coffee powder is stored. Reference numeral 6 is a water container for containing water for extracting the coffee liquid. A heater 7 heats the water in the water pipe 7a whose one end is connected to the bottom of the water container 6. Reference numeral 8 denotes a coffee container, which stores coffee liquid dropped from the filtration chamber 5. Reference numeral 9 is a switching means for switching the energization of the motor 4 and the heater 7, and the timing of the switching operation is set by the timer 10.

The operation of the above configuration will be described. An appropriate amount of coffee beans is put in the crushing chamber 2, and the time of the timer 10 is set according to the scale of the standard time preset according to the amount of coffee beans. When the timer 10 starts operating, the switching means 9 is switched to the motor 4 side, the motor 4 is operated, the cutter 3 is rotated, and the coffee beans housed in the grinding chamber 2 are ground. The ground coffee powder passes through a hole provided at the bottom of the grinding chamber 2 and is stored in the paper filter of the filtration chamber 5 provided below the grinding chamber 2. When the time set by the timer 10 has elapsed, the switching means 9 switches to the heater 7 side,
The heater 7 is energized to heat the water in the water pipe 7a.
A check valve 7b is provided at the connecting portion between the water pipe 7a and the water container 6, and the hot water heated in the water pipe 7a does not flow back into the water container 6 due to the pressure of the partially evaporated water vapor. 2 from the other end of the water pipe 7a opening to the upper part of the crushing chamber 2
Drop on. The hot water flows into the filtration chamber 5 through a hole provided at the bottom of the crushing chamber 2 while washing away the coffee powder remaining in the crushing chamber 2. After dropping for a predetermined time, the switching means 9 once switches to the OFF side and steams the coffee powder for a predetermined time. After that, the switching means 9 is switched to the heater 7 side, all the water in the water container 6 is poured into the coffee powder in the filtration chamber 5, and the coffee liquid is dripped from the opening provided at the bottom of the filtration chamber 5 to make the coffee container. Store in 8.

[0005]

In such a conventional coffee brewing machine, when the timer time is set according to the amount of beans, the time is set according to a scale provided in advance, so that it is difficult to crush. In the case of lightly roasted beans, the timer time ends during the crushing of beans, and conversely, in the case of deeply roasted beans that are easy to crush, the motor continues to operate even if all the beans are crushed, There is a problem in that wasteful electric power is consumed and the motor sound that idles is uncomfortable.

In order to solve such a problem, there is known a structure in which the motor current which changes at the end of crushing coffee beans is detected, and the crushing end is detected and the motor is stopped based on the current change rate and the set current value. Was there.

However, with such a structure, the end of crushing cannot be detected with high accuracy unless the accuracy of the detection circuit is increased in consideration of variations in motor output, motor power supply voltage, and load state. There was a problem.

The present invention solves the above problems by reliably rotating the motor until the entire amount of coffee beans is ground,
A first object of the present invention is to provide a coffee brewing machine that immediately stops the rotation of the motor and starts the extraction of coffee when the whole amount is crushed.

Next, in the conventional coffee brewing machine, the motor rotates for the time set by the timer even when the timer is started in the state where the coffee beans are not contained in the crushing chamber, and when the motor is stopped, the coffee powder is stored in the filtering chamber. There was a problem that the hot water was supplied even though it was not present, and as a result, only hot water was accumulated in the coffee container.

The present invention solves the above-mentioned problems, and it is a second object of the present invention to provide a coffee brewing machine which can quickly stop the operation of the motor when the motor is rotated without the coffee beans in the crushing chamber. Has an aim.

A third object of the present invention is to notify the user that he / she has forgotten to put beans by an alarm sound, avoid the alarm sound from being erased by the noise of the motor, and more surely notify the user of the abnormality.

Next, when beans are inserted into the crushing chamber too much and the beans are rotated simultaneously with the cutter while being sandwiched between the cutter and the crushing chamber inner wall, and abnormal vibration occurs, erroneous determination of the crushing completion detecting means is performed. The fourth purpose is to avoid it.

Next, in the state where the beans are temporarily clogged repeatedly, or when the crushing which obviously exceeds the rated maximum amount is continued, the power supply to the motor is stopped and the motor is operated for a long time. A fifth purpose is to prevent the life from being shortened due to operation.

Next, in the conventional coffee brewing machine, the hot water necessary for steaming is discharged by the switching means. However, since the heater energization time is constant, the quantity of hot water discharged is always constant and one cup of Although it is a proper amount for steaming coffee grounds, hot water cannot be soaked in the case of 5 cups. On the other hand, there is a problem that the extraction is suddenly started because the amount of hot water is too large in the case of 1 cup, which is an appropriate amount for steaming 5 cups of coffee powder.

A sixth object of the present invention is to solve the above problems and to provide a coffee brewer capable of brewing with an appropriate amount of hot water corresponding to the amount of coffee powder.

A seventh object is to reduce the cost by using the piezoelectric element not only as a vibration detecting element but also as a notification element.

[0017]

[Means for Solving the Problems] A first means for solving the above-mentioned first object is a cutter for grinding coffee beans, a grinding chamber in which the cutter is installed, and a motor for driving the cutter. A motor control means for operating and stopping the motor, a heating control means for discharging hot water to the coffee powder ground and stored in the filtration chamber to extract the coffee liquid, and the motor current for a first predetermined time. A current detecting means for measuring each, a crushing chamber when crushing coffee beans, and a vibration detecting element for converting vibration during rotation of the motor into an electric signal, and an amplification and waveform of an output signal of the vibration detecting element The vibration waveform processing means to be processed and the signal of the vibration waveform processing means are measured every second predetermined time, and the difference between the maximum value and the minimum value of the measured values is calculated every third predetermined time, and the difference is calculated. Is the first When the current value measured by the current detection means is within a predetermined range at a time when the state of being equal to or less than a constant value continues for a predetermined number of times, the motor control means stops energization of the motor and operates the heating control means. The crushing completion detecting means is provided.

A second means for solving the second object is to measure the signal of the vibration waveform processing means in addition to the first means immediately before the start of the motor operation and at every fourth predetermined time from the start of the motor operation. However, when the difference from the previous measured value is equal to or larger than the second predetermined value, the crushing completion detecting means is operated, and the state in which the difference from the previous measured value is less than the second predetermined value is the fifth state. When the current value measured by the current detecting means is equal to or larger than the third predetermined value at the time point when the current continues for a predetermined time, the motor controlling means stops the motor and the load detecting means is provided.

The third means for solving the third object is, in addition to the first means, a preset motor self-confidence after the motor control means stops the energization of the motor according to an instruction from the load detection means. Is configured to include a no-load notification unit that waits for a time for idling to continue due to the inertial force and notifies when the noise of the motor becomes small.

A fourth means for solving the fourth object is, in addition to the first means, that the crushing completion detecting means has a difference between the maximum value and the minimum value for a third predetermined time period as a first predetermined value. When it is determined that the state of being equal to or less than the value has continued for a predetermined number of times and the minimum value in the meantime is not less than the fourth predetermined value, the determination of the crushing completion detecting means is invalidated and an instruction is given to perform the determination again The configuration is provided with vibration detection means.

A fifth means for solving the fifth object is, in addition to the first means, a maximum value and a minimum value obtained by the crushing completion detecting means at the time when a sixth predetermined time has elapsed from the start of motor operation. If the difference between the values is equal to or larger than the first predetermined value, the motor control means is provided with abnormal crushing detection means for stopping the motor.

In addition to the first means, a sixth means for solving the sixth object measures the time from the start of the motor operation until the motor control means stops the energization of the motor by the grinding end detection means. However, by operating the time heating control means according to the time, the steaming control means for increasing or decreasing the amount of hot water for steaming the coffee grounds stored in the filtration chamber is provided.

A seventh means for solving the seventh object is a constitution provided with an informing control means for applying a rectangular voltage waveform to the vibration detecting element to emit an informing sound.

[0024]

In the above structure, according to the first means, the crushing completion detecting means measures the signal of the vibration waveform processing means and calculates the difference between the maximum value and the minimum value for the third predetermined time. If the current value measured by the current detecting means is within the predetermined range when the difference is equal to or smaller than the first predetermined value for a predetermined number of times, the motor is idling and is idling. After the determination, the motor control means stops the energization of the motor, and the heating control means starts the energization of the heater. As a result, the end of crushing coffee beans is detected, the operation of the motor is stopped, and coffee extraction is started.

According to the second means, the load detecting means measures the signal of the vibration waveform processing means immediately before the start of the motor operation and at every fourth predetermined time from the start of the motor operation, and a difference between the measured value and the previous value is obtained. When the value is equal to or more than the second predetermined value, the crushing completion detecting unit is instructed to start the measurement, and the state of being less than the second predetermined value is the fifth.
If the current value measured by the current detecting means is equal to or higher than the third predetermined value at the time point when the motor is started, it is determined that no beans have been crushed, and the motor control means Stop energizing. This allows
When coffee beans are put in, crushing is continued, and when coffee beans are not put in, no load is detected and the operation of the motor is stopped.

According to the third means, when no instruction is given from the load detection means, the no-load notification means gives notification when a preset time has elapsed. As a result, the user is more surely notified of the abnormality when the noise of the motor is reduced.

According to the fourth means, the crushing completion detecting means measures the vibration waveform of the vibration waveform processing means, and the difference between the maximum value and the minimum value per the third predetermined time is less than or equal to the first predetermined value. When it is determined that the state has continued for the predetermined number of times, the abnormal vibration detection means determines that the minimum value in the meantime is not less than the fourth predetermined value,
The judgment of the crushing completion detecting means is invalidated, and an instruction is given to make the judgment again. Thereby, the abnormal vibration when the beans are not normally crushed is detected, and the misjudgment of the crushing completion detecting means can be avoided.

According to the fifth means, the abnormal crushing detecting means determines that the difference between the maximum value and the minimum value by the crushing ending detecting means is the first when the sixth predetermined time has elapsed from the start of the motor operation.
If the value is equal to or more than the predetermined value, the motor control means stops the energization of the motor. This avoids a state in which the beans are repeatedly clogged temporarily and a long-time operation of the motor due to crushing that exceeds the maximum rated value.

According to the sixth means, the steaming control means measures the crushing time of the coffee beans by the crushing completion detecting means from the start of the motor operation, and operates the heating control means in accordance with this time. As a result, the heater is energized for a time determined according to the measured time, and steaming is performed with the amount of hot water according to the amount of coffee grounds.

According to the seventh means, the notification control means applies the rectangular voltage waveform to the vibration detecting element to make the notification sound. With this, the vibration can be detected by one vibration detecting element and the notification can be performed.

[0031]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to FIGS.

The same parts as those shown in the conventional example are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 1, reference numeral 11 is a heating control means for controlling ON / OFF of energization of the heater 7.
Reference numeral 12 is a motor control means for turning on / off the power supply to the motor 4.
FF control is performed. A vibration detecting element 13a receives the vibration of the crushing chamber 2 and the motor 4 and outputs a voltage corresponding to the magnitude of the vibration. Reference numeral 14 is a vibration waveform processing means for amplifying the output signal waveform of the vibration detecting element 13a by half wave and smoothing it with a time constant of about 9.4 s. Reference numeral 15 is a current detection means, which amplifies the current waveform of the motor 4 by a half wave and
The peak value is held for each s. Reference numeral 16 is a crushing completion detecting means, the operation of which will be described with reference to FIGS.

FIG. 2 shows the vibration signal waveform by the vibration waveform processing means 14, and FIG. 3 shows the value by the crushing completion detecting means 16 which measures the signal every 10 ms and calculates the difference between the maximum value and the minimum value every 1 s. Is the transition. First, at time t0 in FIG. 2, when the motor control means energizes the motor to start crushing, the waveform suddenly rises due to vibration of the motor 4 and the crushing chamber 2. After that, the waveform changes constantly. Time t
At the time point of 1, the maximum value between t0 and t1 and the difference between the maximum values are obtained. At time t2, the difference between the maximum value and the minimum value between t1 and t2 is obtained, and the same thing is repeated thereafter. Time t5
When all the beans are crushed at the point of time, only stable vibration due to the idling of the motor thereafter, the waveform becomes close to 0, and the difference after time t6 in FIG. 3 also approaches 0. FIG. 4 shows the current detection means 15
Is a current value resulting from a sudden rise at time t0 and then becomes a load current during idling at time t5.

The first means is to measure the current value of FIG. 4 from t6 when the difference between the maximum value and the minimum value becomes less than or equal to the threshold value 1 in FIG. 3 to t10 when the state continues for 4 seconds. Is within the range between threshold 2 and threshold 3, the end of crushing is detected. The threshold value 1 can be easily set because the vibration difference between crushing and idling is large, and the threshold values 2 and 3 can be easily set because the motor is locked and disconnected. It can be easily set without considering. In this embodiment, the threshold value 1 is 0.5 V, the threshold value 2 is 1.7 V, and the threshold value 3 is 0.1 V with respect to the maximum measurable value of 5 V. When it is detected that the coffee beans have been crushed, the motor control means 12 stops energizing the motor 4 and the heating control means 11 starts energizing the heater 7. The hot water heated by the heater 7 is discharged into the crushing chamber 2 in the same manner as in the conventional example, poured into the coffee powder in the filtration chamber 5 and becomes coffee liquid, which is stored in the coffee container 8.

As described above, according to the present embodiment, the crushing completion detecting means 16 detects the difference between the vibrations at the time of crushing and at the end of crushing, and detects the current of the locked or broken state of the motor which cannot be judged only by the vibration. By detecting by means 15, the respective configurations and settings can be simplified, and the end of crushing can be detected with high accuracy.

(Embodiment 2) Next, the second means will be described with reference to FIG.
This will be described with reference to FIG. In FIG. 5, 17 is a load detecting means, and FIG. 6 shows the vibration signal waveform of the vibration waveform processing means 14 measured by the load detecting means 17. First, at the time t00 immediately before the start of motor operation, the first measurement is performed to obtain initial data, and the motor control means starts energizing the motor. Time t 80 ms after t00
At the point of 01, the second measurement is performed and the difference from the initial data is obtained. If the difference is equal to or more than a predetermined value, it is determined that the beans are crushed, the subsequent measurement is stopped, and the crushing completion detecting means 16 is instructed to start the measurement. If the difference is less than or equal to a predetermined value, the third measurement is performed at time t02, which is 80 ms after t01, and the difference from the data at time t01 is obtained. After that, if the difference is less than or equal to a predetermined value, the same thing is repeated, and at the time when the maximum time tmax is reached from time t00, if the current measurement value by the current detecting means 15 is the threshold value 3 or more, the beans are put in. It is determined that there is no motor control means
The power supply to the motor 4 is stopped by 2 and the subsequent extraction operation is stopped. In this embodiment, the predetermined value is ± 0.8 V, tma
x can be variably set to 0.3 s to 4 s, and the difference without beans is usually ± 0.1 V or less.

As described above, according to the present embodiment, by detecting the rising of the vibration signal at the time of crushing by the load detecting means 17, it is possible to instantly and accurately detect the presence or absence of beans.

(Embodiment 3) Next, the third means will be described with reference to FIG.
Will be described with reference to. In FIG. 7, reference numeral 18 denotes a no-load notification means, and the load detection means 17 determines that there is no beans, and after the motor control means 12 stops energizing the motor 4, the no-load notification means 18 waits for a predetermined time and there is no beans. Make a notification to inform that. According to this embodiment, the motor is almost not rotated after waiting for 2 seconds, and the notification is given in a state where the noise is small.

As described above, according to the present embodiment, by controlling the timing of the notification by the no-load notification means 18, the user can be more surely notified of the forgetting to put the beans.

(Fourth Embodiment) Next, the fourth means will be described with reference to FIG.
Will be described with reference to. When there is a signal from the crushing completion detecting means 16 that the crushing of beans has been detected, abnormal vibration detecting means 19 is provided for checking the crushed state and determining whether the signal is valid or invalid. The operation will be described with reference to FIG.

FIG. 9 shows a vibration generated by the vibration waveform processing means 14 when the beans are sandwiched between the cutter 3 and the inner wall of the crushing chamber 2 due to the excessive amount of beans that have entered the crushing chamber 2 during the crushing process and the cutter 3 simultaneously rotates. This is a signal waveform, and FIG. 10 is a measurement value by the crushing completion detecting means 16. In this example, since the beans start to rotate at the same time as the cutter 3 at the time t4 and the crushing is not normally performed, the difference between the maximum value and the minimum value is equal to or less than the threshold value 1. 16 detects the end at time t9. This is because the vibration during abnormal crushing was much larger than usual, so the maximum measurable value was shaken off, and the difference between the maximum and minimum values was compressed. In order to detect this abnormal crushing, the abnormal vibration detecting means 19 compares the measured minimum value from the time t5 to t9 when the crushing end detecting means 16 detects the end with the threshold value 4, and if it is the threshold value 4 or more. It is determined that the crushing is abnormal, and the crushing end detecting means 16 is instructed to perform the end detection again.

As described above, according to this embodiment, the abnormal vibration detecting means 19 detects the vibration at the time of abnormal crushing, so that the crushing completion detecting means 16 can be prevented from making an erroneous determination.

(Embodiment 5) Next, referring to FIG.
1 will be described. In FIG. 11, reference numeral 20 is an abnormal crushing detection means, and when the motor control means 12 starts energizing the motor, the abnormal crushing detection means 20 starts time measurement, and when a predetermined time elapses, the crushing end detection means 1
The latest data of the difference between the maximum value and the minimum value according to 6 is read.
If the latest data is equal to or smaller than the threshold value 1, the difference data is continuously read until the difference data becomes equal to or larger than the threshold value 1. If the difference data is the threshold value 1 or more, the motor control means 1
The power supply to the motor is stopped by 2 and the user is informed by an alarm sound that the crushing time is abnormal. Usually, the maximum time required for crushing 5 cups of beans is about 40 seconds, and the time is set to 1 minute in this embodiment.

As described above, according to this embodiment, the abnormal crushing detecting means 20 prevents the motor from operating for a long time, so that the life of the motor can be extended.

(Embodiment 6) Next, the sixth means will be described with reference to FIG.
This will be described with reference to 2. In FIG. 12, 21 is a steaming control means, which measures the time from the start of energization of the motor 4 by the motor control means 12 to the judgment of the end of grinding by the grinding end detection means 16, and the heating control means 11 determines the time required for this grinding. The heater 7 is energized for a predetermined time to discharge the amount of hot water required for steaming. In the present embodiment, the steaming control means 21 sets 1 when the measured crushing time is less than 17 seconds.
When the time is 8 s or more and less than 27 s, and when it is 27 s or more, the energizing time of the heater 7 is 7.2 s, 12 s, and 21 s, respectively.
Have controlled as. As a result, 1 to 2 coffee grounds
The amount of hot water discharged in the cup is about 20 cc to 30 cc, about 55 cc to 60 cc in the case of 3 cups, and about 95 to 110 cc in the case of 4 to 5 cups, which is an appropriate amount required for steaming.

As described above, according to the present embodiment, the amount of coffee powder can be grasped by detecting the crushing time of beans by the steaming control means 21, and steaming is performed with the amount of hot water corresponding to the amount, so that it is more delicious. Coffee can be extracted.

(Embodiment 7) Next, the seventh means will be described with reference to FIG.
This will be described with reference to FIG. In FIG. 13, a piezoelectric buzzer is used for the vibration detecting element 13b, and a printed board having its terminal portion soldered is attached to the support plate of the motor 4 in order to prevent the sound pressure from being lowered. In this configuration, the notification control unit 22 prohibits the notification when the motor 4 is energized by the motor control unit,
When the motor 4 is not energized, a rectangular voltage waveform of 4 kHz is applied to the vibration detecting element 13b as necessary to generate an alarm sound.

As described above, according to the present embodiment, one piezoelectric element can be used for both vibration detection and notification by the notification control means 22, and the cost can be reduced.

[0050]

As is apparent from the above embodiments, according to the first means, by providing the crushing completion detecting means,
It is possible to detect the end of coffee bean crushing with high accuracy with a simple configuration, and to quickly stop the operation of the motor and start the extraction of coffee.

In the second means, by providing the load detecting means, the presence or absence of beans can be instantly detected at the time of starting the motor,
When the absence of beans is detected, the operation of the motor is promptly stopped and the coffee extraction operation is stopped, so that coffee can be extracted without failure.

In the third means, by providing the no-load notification means, it is possible to more surely notify the user that the beans have been forgotten.

In the fourth means, since the abnormal vibration detecting means is provided, it is possible to detect the abnormal vibration due to too much beans entering the crushing chamber, so that the erroneous determination of the crushing completion detecting means can be avoided. .

In the fifth means, since the abnormal crushing detecting means is provided, it is possible to avoid the long-time operation of the motor due to the abnormal crushing state, so that the life of the motor can be extended.

In the sixth means, since the brewing control means is provided, brewing can be performed with an appropriate amount of hot water corresponding to the amount of coffee powder, so that more delicious coffee can be extracted.

In the seventh means, since the piezoelectric element can be used for both vibration detection and notification by providing the notification control means, the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a coffee brewer according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a vibration signal waveform by a vibration waveform processing means.

FIG. 3 is a diagram showing an example of measured values by a crushing completion detecting means.

FIG. 4 is a diagram showing an example of a current measurement value by a current detection means.

FIG. 5 is a configuration diagram showing a coffee brewer according to a second embodiment of the present invention.

FIG. 6 is a diagram showing an example of measured values by a load detection means.

FIG. 7 is a block diagram showing a coffee brewer according to a third embodiment of the present invention.

FIG. 8 is a configuration diagram showing a coffee brewer according to a fourth embodiment of the present invention.

FIG. 9 is a diagram showing an example of a vibration signal waveform by a vibration waveform processing means during abnormal crushing.

FIG. 10 is a diagram showing an example of measured values by a crushing completion detecting means at abnormal crushing.

FIG. 11 is a configuration diagram showing a coffee brewer according to a fifth embodiment of the present invention.

FIG. 12 is a configuration diagram showing a coffee brewer according to a sixth embodiment of the present invention.

FIG. 13 is a configuration diagram showing a coffee brewer according to a seventh embodiment of the present invention.

FIG. 14 is a configuration diagram showing a conventional coffee brewer.

[Explanation of symbols]

 2 crushing chamber 4 motor 5 filtration chamber 11 heating control means 12 motor control means 13a, 13b vibration detection element 14 vibration waveform processing means 15 current detection means 16 crushing end detection means 17 load detection means 18 no-load notification means 19 abnormal vibration detection means 20 Abnormal Grinding Detection Means 21 Steaming Control Means 22 Notification Control Means

Claims (7)

[Claims] 1. A cutter for crushing coffee beans, a crushing chamber in which the cutter is installed, a motor for driving the cutter, a motor control unit for operating and stopping the motor, and a crushed filter chamber. Heating control means for discharging hot water to the stored coffee powder to extract coffee liquid,
A current detecting means for measuring the motor current at every first predetermined time, the crushing chamber for crushing coffee beans, and a vibration detecting element for converting vibration during rotation of the motor into an electric signal, and the vibration. A vibration waveform processing unit that amplifies and waveform-processes the output signal of the detection element, and a signal of the vibration waveform processing unit is measured every second predetermined time, and the difference between the maximum value and the minimum value of the measured values is determined by the third value. If the current value measured by the current detection means is within a predetermined range when the difference is less than or equal to the first predetermined value for a predetermined number of times, the current value is calculated by the motor control means. A coffee brewing machine, comprising: a crushing completion detecting means for stopping energization of a motor to operate the heating control means. 2. The signal of the vibration waveform processing means is measured immediately before the motor starts and at every fourth predetermined time from the start of motor operation, and when the difference from the previous measured value is equal to or larger than the second predetermined value. When the crushing completion detecting means is operated and the state where the difference from the previous measured value is less than the second predetermined value continues for the fifth predetermined time, the current value measured by the current detecting means is 3. The coffee brewing machine according to claim 1, further comprising load detecting means for stopping the motor by the motor control means if the value is equal to or larger than the predetermined value of 3. 3. The motor control means stops the energization of the motor according to an instruction of the load detection means, and then waits for a preset idle time by the inertial force of the motor itself to notify when the noise of the motor becomes small. The coffee brewing machine according to claim 1, further comprising a no-load notification means for performing the above. 4. When the crushing completion detecting means determines that the state where the difference between the maximum value and the minimum value per third predetermined time is less than or equal to the first predetermined value continues for a predetermined number of times, the minimum value therebetween is A coffee brewing machine comprising abnormal vibration detecting means for invalidating the judgment of the crushing completion detecting means and for instructing to make another judgment if the value is not less than the fourth predetermined value. 5. The motor control means stops the motor if the difference between the maximum value and the minimum value by the crushing completion detecting means is equal to or more than the first predetermined value when the sixth predetermined time has elapsed from the start of the motor operation. The coffee brewing machine according to claim 1, further comprising abnormal crushing detecting means for causing the abnormal crushing. 6. The filtration chamber is accommodated by measuring the time from the start of the motor operation until the motor control means stops the energization of the motor by the grinding end detection means, and operating the time heating control means according to the time. The coffee brewing machine according to claim 1, further comprising steaming control means for increasing or decreasing the amount of hot water for steaming the ground coffee powder. 7. The coffee brewing machine according to claim 1, further comprising notification control means for applying a rectangular voltage waveform to the vibration detecting element to generate a notification sound.