JP2003199501A - Method for controlling hardness of frozen dessert material, introduced in apparatus for making frozen dessert - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling hardness of frozen dessert material, introduced in an apparatus for making frozen dessert, exactly detecting a fatigue condition or a softened state each caused on frozen dessert (raw material for frozen dessert) caused by deficiency in chilling. <P>SOLUTION: The method for controlling hardness of frozen dessert material comprises a raw material tank 8 storing frozen dessert material 24, a freezer body 1 which communicates with the raw material tank 8 and in which the frozen dessert material 24 is chilled with a refrigerant to be formed into a frozen dessert 25, a mixer 2 which stirs the frozen dessert material 24 in the freezer body 1 via an electric motor 7 as a driving force, and a refrigeration cycle for supplying the refrigerant to the freezer body 1. This apparatus detects the number of frozen dessert taking-out times per the predetermined period of time to make a judgement that the frozen dessert 25 is in a softened state caused by deficiency in chilling, and displays the softened state on a fatigue- condition displaying part 53 and the softening-state displaying part 54 to stop taking out the dessert from the freezer. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the hardness of a frozen dessert producing apparatus for producing frozen desserts such as soft ice cream and shakes. 2. Description of the Related Art FIG. 3 shows an example of a conventional frozen dessert production apparatus. FIG. 3 is a diagram showing a raw material tank / freezer cylinder and a refrigerant piping system (refrigeration cycle) of the frozen dessert production apparatus. In the figure, reference numeral 1 denotes a freezer body that cools the frozen dessert material 24 into a frozen dessert 25, and 8 denotes a raw material tank that stores the frozen dessert material 24 and supplies the frozen dessert material 1 to the freezer body 1. The raw material tank 8 is provided above the freezer body 1 so that the frozen dessert raw material communicates via a carburetor tube 9. A heat transfer tube 21 is wound around the raw material tank 8, and a jacket 3 is provided around the freezer body 1. A stirrer 2 is disposed inside the freezer cylinder 1, and the driving force of the stirrer 2 is transmitted from a motor 7 installed outside the freezer cylinder 1 via the rotating shaft 4. . The freezer body 1 is provided with a freezer lid 23 for closing one end opening, and the freezer lid 23 is provided with the lever 11. A through hole 31 is provided in the freezer lid 23, and is closed and opened by the plunger 14 that is interlocked with the lever 11. The heat transfer tube 21 and the jacket 3 have a compressor 1
The refrigerant sent by 5 flows, thereby cooling the frozen dessert raw material 24 and the frozen dessert 25,
The refrigerant flow path includes a four-way valve 16, a condenser 17, an expansion valve 2,
0, an expansion valve 22 is provided. By connecting these four-way valve 16, the condenser 17, the expansion valves 20, 22, the heat transfer tube 21, and the jacket 3 by piping that serves as a refrigerant flow path, a refrigeration cycle in which the refrigerant circulates while repeating a state change is configured. ing. Also, the whole frozen dessert production equipment
It is controlled by a control device (not shown). [0005] This frozen dessert production apparatus is used as follows. First, the raw material tank 8 is filled with the frozen dessert raw material 24 prior to the cooling operation. The frozen dessert raw material 24 includes the hole 10 provided in the carburetor tube 9 and the carburetor tube 9.
It is also filled into the freezer cylinder 1 through the inside. If it takes time to fill the freezer cylinder 1 through the carburetor tube hole 10 and the carburetor tube 9, before inserting the carburetor tube 9, a predetermined amount of the frozen dessert material 24 May be put in. Next, a cooling operation is performed. When the electric motor 7 and the compressor 15 are operated by the control device, the refrigerant gas is discharged from the compressor 15 to the discharge pipe 41. The refrigerant gas flows through the discharge pipe 41 through the condenser 1 as indicated by the solid arrow in the figure.
7 and is condensed and liquefied by radiating heat to cooling water flowing through the heat transfer tube 18 inside the condenser 17. This liquid refrigerant then branches into two, one of which is adiabatically expanded by being throttled by an expansion valve 20, and then evaporates and evaporates in the course of flowing through the heat transfer tube 21, and the latent heat of evaporation causes the liquid refrigerant to flow into the raw material tank 8. Is cooled. The other liquid refrigerant is adiabatically expanded by being throttled by the expansion valve 22, and then evaporated and vaporized in the jacket 3 to cool the frozen dessert raw material 24 in the freezer body 1 by its latent heat of evaporation. The refrigerant gas evaporated in the heat transfer tube 21 and the refrigerant gas evaporated in the jacket 3 join to form a suction pipe 40.
, And is sucked into the compressor 15 to repeat the above process. During this time, the stirrer 2 is driven by the electric motor 7 via the rotating shaft 4 to stir the frozen dessert raw material 24 in the freezer cylinder 1. If the cooling operation is continued for a while, the frozen dessert raw material 24 in the freezer body 1
Is frozen to form frozen dessert 25. Thereafter, the cooling dessert 25 is controlled to maintain a predetermined hardness by repeating the cooling operation and the stop and start of the stirrer 2. A specific conventional hardness control is to calculate a torque from the electric current of the electric motor 7 and, when the torque rises to a set value, in other words, to increase the hardness of the frozen dessert 25 to increase the hardness of the agitator 2. This is performed by a torque control method in which the cooling operation is stopped when the load rises to a predetermined value, and the cooling operation is restarted after the cooling operation is stopped for a predetermined time. To take out the frozen dessert 25, the lever 11 is pulled downward. Plunger 14 that operates in conjunction with lever 11
Moves upward, the takeout switch 13 is closed, and the through hole 31 is opened. Then, the frozen dessert 25 in the freezer body 1 is taken out from the outlet 33 through the through hole 31. Compressor 1 while take-out switch 13 is closed
5 and the electric motor 7 continue to run, and then stop. After the store is closed every day, a heat sterilization operation for heating and sterilizing the frozen dessert material 24 in the raw material tank 8 and the frozen dessert material 24 and the frozen dessert 25 in the freezer body 1 is performed. During the heat sterilization operation, the high-temperature and high-pressure refrigerant gas discharged from the compressor 15 is branched into two after passing through a four-way valve 16 as shown by a broken line arrow in the drawing, and one flows through the heat transfer tube 21. In the process, the frozen dessert raw material 24 in the raw material tank 8 is heated and condensed and liquefied, and then is adiabatically expanded by being throttled by the expansion valve 20. The other enters the jacket 3, where the frozen dessert raw material 24 and the frozen dessert 25 in the freezer body 1 are sterilized by heating, condensed and liquefied, and then adiabatically expanded by being squeezed by the expansion valve 22. The refrigerant flowing through the expansion valve 20 and the expansion valve 22 merges and enters the condenser 17, where the refrigerant absorbs heat from the cooling water flowing through the heat transfer pipe 18, evaporates, and then passes through the four-way valve 16. It is sucked into the compressor 15. In the above-mentioned conventional frozen dessert production apparatus, the control of the hardness of the frozen dessert 25 in the freezer body 1 is important for obtaining a good texture, and the conventional dessert has a higher torque. A control method is adopted. This torque control method focuses on the fact that a change in hardness results in a load change, and calculates the torque from a current value flowing through the electric motor 7 of the stirrer 2 to determine the hardness. However, in this method, FIG.
As shown in (1), since the characteristics of the current value and the torque (load) change with the voltage fluctuation of the power supply, it is difficult to accurately determine the hardness. That is, when the current value is i, the load is k2 if the rated voltage v is indicated by a solid line.
However, as shown by the broken line, when the voltage fluctuates to the plus side or the minus side, the load also changes to k1 or k3, so that it was not possible to determine the exact hardness only from the current value.
It should be noted that although voltage fluctuations can be corrected, it is not possible to correct the three-phase correlation voltage balance. Further, even when the frozen dessert 25 is not taken out, the cooling operation and the stirrer 2 are performed to maintain the predetermined hardness.
Start / stop is repeated. If this is continued for a long time, the air content of the frozen dessert 25 changes and becomes soft even at the same temperature, so that a so-called "set" is obtained, and the texture and shape retention are reduced. Conventionally, such determination of the set state (set detection) is performed by counting the amount of the frozen dessert 25 taken out within a predetermined time and determining that the set amount does not reach the predetermined number. There was a problem. If the frozen dessert 25 is continuously taken out, the cooling capacity of the freezer cylinder 1 cannot keep up, and the replenished frozen dessert raw material 24 is not sufficiently cooled, so that it may be taken out while being soft. However, the conventional means for detecting such a softened state of insufficient cooling is inaccurate because it is a torque control method for judging from the current value of the electric motor 7 driving the stirrer 2 as in the above-described hardness control. There was a problem. In view of the above circumstances, an object of the present invention is to provide a frozen dessert manufacturing apparatus capable of accurately determining the softened state of the frozen dessert (the frozen dessert raw material) due to insufficient cooling, and a method for controlling the hardness of the dessert. In order to solve the above-mentioned problems, the present invention employs the following means. The method for controlling the hardness of a frozen dessert manufacturing apparatus according to claim 1, wherein the frozen dessert raw material is accommodated in a raw material tank; And a refrigeration cycle for supplying a refrigerant to the freezer body with a stirring means for agitating the frozen confectionery material in the freezer body using the drive source as a drive source. Detecting the number of times, when the number of times of taking out the frozen dessert is equal to or more than a predetermined number of times, determining that the frozen dessert is in a softened state of insufficient cooling, and displaying it on the display means to stop taking out the dessert. . According to such a method for controlling the hardness of a frozen dessert production apparatus, the number of the desserts which can be continuously taken out can be known in advance from the cooling capacity of the apparatus. The removal can be stopped by accurately determining the softened state of insufficient cooling. Next, an embodiment according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a frozen dessert production apparatus according to the present embodiment, and FIG. 2 is a diagram showing a correlation between an output signal and a motor output torque value of a motor that has been subjected to inverter control. In FIG. 1, reference numeral 1 denotes a frozen dessert material 2
It is a freezer body that cools 4 to make frozen dessert 25,
Numeral 8 is for storing frozen dessert raw material 24 and for freezer cylinder 1
Is a raw material tank for supplying the frozen dessert raw material 24 to the raw material. The raw material tank 8 is provided above the freezer body 1 so that the frozen dessert raw material 24 is communicated through the carburetor tube 9. A heat transfer tube 21 is wound around the raw material tank 8, and a jacket 3 is provided around the freezer body 1. A stirrer 2 is arranged inside the freezer cylinder 1, and the stirrer 2 is configured such that a driving force is transmitted via a rotating shaft 4 from an electric motor 7 installed outside the freezer cylinder 1. I have. The electric motor 7 is connected to an inverter control unit 7A.
And the inverter control unit 7A
The motor output torque value 51 detected by the
Is input to The hardness controller 50 determines the load of the stirrer 2, that is, the hardness of the frozen dessert 25 (the frozen dessert raw material 24) from the motor output torque value 51, and outputs a control signal 52 for controlling the hardness. In addition, the code | symbol 53 in a figure is frozen dessert 2.
5 is a set display unit for displaying when the set state is detected, and 54 is a softening display unit for displaying when a softened state due to insufficient cooling is detected, and both are display means such as a lamp display. Further, the freezer body 1 is provided with a freezer lid 23 for closing one end opening thereof, and the freezer lid 23 is provided with the lever 11. Freezer lid 23
Is provided with a through hole 31, which is closed and opened by a plunger 14 interlocked with the lever 11. Reference numeral 13 in the drawing is a takeout switch that detects the open / closed state of the plunger 14 in conjunction with the operation of the lever 11. The refrigerant is flowed into the heat transfer tube 21 and the jacket 3 by the compressor 15 which compresses and sends out the gas refrigerant, thereby cooling the frozen dessert raw material 24 or the frozen dessert 25. The refrigerant flow path constitutes a refrigeration cycle similar to that of the related art, and a refrigerant pipe 34 that returns the refrigerant from the heat transfer tube 21 and the jacket 3 to the compressor 15 and a refrigerant that sends the refrigerant from the compressor 15 to the heat transfer tube 21 and the jacket 3 And a tube 35. The refrigerant pipe 34 and the refrigerant pipe 35 are connected to the compressor 15 via the four-way valve 16.
The four-way valve 16 and the compressor 15 are connected by a suction pipe 40 and a discharge pipe 41. A condenser 17 for cooling the high-temperature and high-pressure gas refrigerant sent from the compressor 15 is interposed in the refrigerant pipe 35. Further, the refrigerant pipes 35 on the downstream side are the refrigerant pipes 35 on the heat transfer tube 21 side and the jacket 3 side.
a and 35b, and expansion valves (expansion means) 20 and 22 for decompressing and expanding the high-temperature and high-pressure liquid refrigerant discharged from the condenser 17 are interposed. The detection signal of the take-out switch 13 and the control signal 52 output from the hardness control unit 50 are input to a control device (not shown) and used for operation control of the entire device. Here, the motor output torque value directly detected by the inverter control section 7A will be described with reference to FIG. This motor output torque value is proportional to an output signal (DC voltage value) output from the inverter control unit 7A of the motor 7. For example, the power supply is 60Hz
Is 100%, the output signal is output as a DC voltage of α (V). When the load decreases and the torque value decreases to 50%, an output signal of 0.5α (V) is output. Signal. Thus, if the load (motor output torque value) of the stirrer 2 that fluctuates due to the hardness of the frozen dessert 25 is detected in the form of an output signal, the hardness can be accurately determined without being affected by the voltage. . When the motor output torque value 51 detected by the DC voltage value becomes higher than a predetermined value, the frozen dessert 25
Outputs a control signal to the control unit (not shown) that determines that further cooling is not required, so that the supply of the cooling refrigerant from the refrigeration cycle to the freezer cylinder 1, specifically, to the jacket 3 is stopped. And adjust the hardness. In this way, the load of the electric motor 7 is directly detected from the electric motor output torque value 51 to determine the hardness of the frozen dessert 25, and a control signal 52 based on this determination is output to perform the hardness control. In the method, since the voltage of the power supply is not involved in the calculation and detection process, the hardness of the frozen dessert 25 can be accurately determined without being affected by the voltage fluctuation. Then, during the operation for maintaining the hardness of the frozen dessert 25 which has once become the predetermined hardness, when the above-mentioned electric motor output torque value 51 does not rise to the predetermined value, that is, the cooling operation and the stirring are performed beyond the predetermined time. If the frozen dessert 25 does not reach the predetermined hardness even after continuing, it can be determined that the frozen dessert 25 is set. Also in this case, it is detected that the load on the stirrer 2 does not increase because the frozen dessert 25 is soft, and the occurrence of set can be accurately determined. In this manner, when it is determined that the frozen dessert 25 is in the set state, the set display 53
And a control signal 52 is output to perform a thawing regeneration operation for thawing the frozen dessert 25 and then cooling it again. Note that the set display unit 53 can also use a sound such as a buzzer in addition to a visual display for lighting a lamp or the like. Further, when the frozen dessert 25 is continuously taken out, the frozen dessert material 24 is replenished to the freezer cylinder 1 by the number of times of taking out from the raw material tank 8, so that the cooling capacity cannot keep up and the desired hardness cannot be maintained. There is. Also in such a case, since the motor output torque value 51 does not increase to the predetermined value, if the condition of the continuous take-out state which is detected from the detection signal of the take-out switch 13 is satisfied, it may be determined that the frozen dessert 25 is in a softened state due to insufficient cooling. it can. Also in this case, frozen dessert 2
By detecting that the load of the stirrer 2 does not rise because of the softness of 5, the softened state due to insufficient cooling can be accurately determined. In this way, when it is determined that the frozen dessert 25 is in a softened state with insufficient cooling, it is displayed on the softened display unit 54 and outputs a control signal 52 to stop taking out the frozen dessert 25 and perform cooling and stirring. Note that the softening display unit 54 can also use a sound such as a buzzer or the like in addition to the visual display for turning on a lamp or the like, similarly to the set display unit 53 described above. The frozen dessert manufacturing apparatus having the above-described configuration is used as follows. First, before the cooling operation, the raw material tank 8
The inside is filled with frozen dessert material 24. The frozen dessert material 24 is also filled into the freezer cylinder 1 through the carburetor tube 9. At the same time, the carburetor tube 9 whose upper end is opened at a position higher than the highest liquid level of the frozen dessert raw material 24.
, Air at atmospheric pressure is introduced into the freezer body 1. Note that the filling of the frozen dessert material 24 and the introduction of air are completed when the lower end opening of the carburetor tube 9 is closed by the liquid level. If it takes a long time to fill the freezer cylinder 1 through the carburetor tube 9, before inserting the carburetor tube 9, a predetermined amount of the frozen dessert raw material 24 is put in the freezer cylinder 1 in advance. No problem. Next, a cooling operation is performed. When the electric motor 7 and the compressor 15 are operated by the control device, the refrigerant gas is discharged from the compressor 15 to the discharge pipe 41. Fig. 1
As shown by the solid line arrow in FIG.
6, the refrigerant enters the condenser 17 through the refrigerant pipe 35, and the condenser 17
By radiating the heat to the cooling water flowing through the internal heat transfer tube 18, the temperature further decreases. This liquid refrigerant branches into two refrigerant pipes 35 a and 35 b, one of which is adiabatically expanded by being throttled by the expansion valve 20, and then evaporates and evaporates in the course of flowing through the heat transfer pipe 21, thereby causing the latent heat of vaporization thereof. Thus, the frozen dessert raw material 24 in the cooling tank 8 is kept cool. The other liquid refrigerant is adiabatically expanded by being throttled by the expansion valve 22, and then evaporated and vaporized in the jacket 3 to cool the frozen dessert material 24 or the frozen dessert 25 in the freezer body 1 by the latent heat of evaporation. At this time, the electric motor 7 is started and the stirrer 2 is started.
Is driven to stir the frozen dessert 25, but the electric motor output torque value 51 is directly input from the inverter control unit 7A to the hardness control unit 50, and the hardness of the frozen dessert 25 is determined. The refrigerant gas evaporated in the heat transfer pipe 21 and in the jacket 3 joins in the refrigerant pipe 34 and enters the suction pipe 40.
, And is sucked into the compressor 15 to repeat the above process. During this time, the stirrer 2 is driven by the electric motor 7 via the rotating shaft 4 to stir the frozen dessert raw material 24 in the freezer body 1. If the cooling operation is continued for a while, the frozen dessert material 2 in the freezer body 1
4 freezes to become frozen dessert 25. In this process, when the frozen dessert 25 has a predetermined hardness, the load of the stirrer 2 increases and the electric motor 7
Increases to a predetermined value. In such a state, the hardness control unit 50
In the above, it is determined from the motor output torque value 51 that the frozen dessert 25 has a predetermined hardness, and the cooling operation for supplying the cooling refrigerant to the jacket 3 is stopped. Then, the cooling operation is started again, for example, after a lapse of a predetermined time from the stop of the cooling operation, or when a detection value of a temperature detecting means (not shown) provided in an appropriate place rises to a predetermined value. Thereafter, by repeatedly stopping and starting the cooling operation, the frozen dessert 25 is controlled so as to maintain a predetermined hardness. When it is determined that such a hardness maintaining operation has continued for a long time and a set has occurred, the set is displayed on the set display 53, and the control signal 52 is output to automatically defrost. The regeneration operation is started. When the thawing / regenerating operation is performed by a manual switch (not shown), the set display 53
It is also possible to show only the display. The appropriate hardness of the frozen dessert 25 and the hardness of the frozen dessert 25 for judging occurrence of sagging are completely different between the case where the frozen dessert 25 is a soft cream and the case where the frozen dessert 25 is a shake, for example. It is preferable to be able to switch by providing a selection switch. The cooling control of the raw material tank 8 is separated from the cooling operation control of the freezer body 1 described above.
Is maintained at 10 ° C. or less. To take out the frozen dessert 25, the lever 11 is pulled downward. Plunger 14 that operates in conjunction with lever 11
Moves upward, the takeout switch 13 is closed, and the through hole 31 is opened. Then, the frozen dessert 25 in the freezer body 1 is taken out from the outlet 33 through the through hole 31. Compressor 1 while take-out switch 13 is closed
5 and the electric motor 7 continue to run, and then stop.
When the frozen dessert 25 is thus taken out, the frozen dessert raw material 24 and the air are supplied to the stirrer 2 side, and the liquid level is reduced accordingly. Therefore, the frozen dessert raw material 24 and air are supplied into the freezer body 1 from the raw material tank 8 and the atmosphere via the carburetor tube 9. In this case, if the extraction of the frozen dessert continues more than the cooling capacity, the electric motor output torque value 51 decreases, so the hardness control unit 50 determines that the softened state is due to insufficient cooling. When this determination is made, it is displayed on the softening display unit 54, and the removal of the frozen dessert 25 is stopped until the softening display is canceled, that is, until the hardness becomes a predetermined hardness. After the store is closed every day, a heat sterilization operation for heating and sterilizing the frozen dessert material 24 in the raw material tank 8 and the frozen dessert material 24 and the frozen dessert 25 in the freezer body 1 is performed. During the heat sterilization operation, the high-temperature and high-pressure refrigerant gas discharged from the compressor 15 is introduced into the refrigerant pipe 34 from the four-way valve 16 as shown by a dashed arrow in FIG. After that, it branches into two, and one of the two is in the course of flowing through the heat transfer tube 21 and the frozen dessert raw material 2 in the raw material tank 8.
4 is heated and condensed and liquefied.
The adiabatic expansion is performed by being throttled by the expansion valve 20 interposed in a. The other enters the jacket 3, where the frozen dessert raw material 24 and the frozen dessert 25 in the freezer body 1 are heat-sterilized and condensed and liquefied, and then squeezed by the expansion valve 22 interposed in the refrigerant pipe 35 b to be insulated. Swell.
The refrigerant flowing through the expansion valve 20 and the expansion valve 22 merges and enters the condenser 17, where the refrigerant absorbs heat from the cooling water flowing through the heat transfer pipe 18, evaporates, and then passes through the four-way valve 16. It is sucked into the compressor 15. Next, another embodiment for judging the softened state of insufficient cooling will be described. In this embodiment, the number of times of taking out the frozen dessert within a predetermined time is detected by the extraction switch 13, and when the number of times of taking out the frozen dessert becomes equal to or more than the predetermined number, it is determined that the frozen dessert is in a softened state of insufficient cooling. That is, the number of frozen desserts 25 exceeding the preset number within a preset short time period
Is taken out, the frozen dessert raw material 24 having a cooling capacity or more is replenished.
Is not able to catch up and is not sufficiently cooled, resulting in a soft frozen dessert 25. Therefore, even when the softened state of insufficient cooling is detected in this way, the display is displayed on the softened display unit 54 and the removal is stopped in the same manner as in the case where it is determined from the motor output torque value 51 described above. Since the cooling capacity of the frozen dessert manufacturing apparatus can be known in advance as the performance of the apparatus itself, it is easy to know in advance by calculation or an experiment the number of the frozen desserts that can be continuously taken out. As described above, in the frozen dessert manufacturing apparatus and the hardness control method of the present invention, the hardness is determined using the motor output torque value 52 directly detected from the inverter control unit 7A of the motor 7. Therefore, it is possible to accurately determine the hardness without being affected by the voltage fluctuation of the power supply that changes in the surroundings, and to maintain the frozen dessert 25 in a stable hardness. In addition, it is possible to accurately determine the set state of the frozen dessert 25 and the softened state due to insufficient cooling, similarly to the determination of the hardness. The configuration of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the scope of the present invention. As described above, according to the method for controlling the hardness of a frozen dessert manufacturing apparatus according to the present invention, the number of times of taking out the dessert within a predetermined time is detected, and the number of times of taking out the dessert is equal to or more than the predetermined number of times. When it is determined that the frozen dessert is in a softened state with insufficient cooling, and the display is displayed on the display means to stop the extraction, the number of continuous extractions within a predetermined time is detected for the softened state with insufficient cooling, and a predetermined number is determined. When the number of times is equal to or more than the number of times, the softened state is determined, so that a more accurate determination can be made than the conventional method in which the current value of the electric motor driving the stirrer is used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view and a diagram showing a piping system of a frozen dessert manufacturing apparatus shown as one embodiment of the present invention. FIG. 2 is a diagram illustrating a relationship between an output signal of a motor and an output signal detected by an inverter control unit used in the frozen dessert manufacturing apparatus of FIG. 1; FIG. 3 is a cross-sectional view and a diagram showing a piping system of a conventional frozen dessert manufacturing apparatus. FIG. 4 Load (hardness) of a motor in a conventional stirrer
FIG. 4 is a diagram showing a relationship between the current and the current value. [Description of Signs] 1 Freezer cylinder 2 Stirrer (stirring means) 7 Electric motor 7A Inverter control unit 8 Raw material tank 15 Compressor 16 Four-way valve 24 Cold dessert raw material 25 Cold dessert 50 Hardness control unit 51 Electric motor output torque value 52 Control signal 53 Rake display section (display means) 54 Softening display section (display means)

Claims (1)

Claims: 1. A raw material tank containing a frozen dessert material, a freezer body communicating with the raw material tank and cooling the frozen dessert material by a refrigerant to form a frozen dessert, and an electric motor as a drive source. In a method for controlling the hardness of a frozen dessert manufacturing apparatus comprising a stirring means for stirring the frozen dessert material in the freezer body and a refrigeration cycle for supplying a refrigerant to the freezer body, detecting the number of times of taking out the frozen dessert within a predetermined time, Determining the frozen dessert in a softened state with insufficient cooling when the number of times of taking out the frozen dessert is equal to or greater than a predetermined number, and displaying the display on the display means to stop taking out the frozen dessert; .