JPH0422235Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to an operation control device for a water circulation type ice maker, and in particular, the present invention relates to an operation control device for a water circulation type ice maker, and is particularly concerned with the problem caused by muddy or floc-like incomplete ice (hereinafter referred to as fluff ice) that is unique to water circulation type ice makers and occurs in the ice making water circulation path. This invention relates to an operation control device for a water circulation type ice maker to eliminate problems.

[Conventional technology]

A water circulation type ice maker is a ice making machine that supplies ice making water in an ice making water tank to the ice making section using a circulation pump, receives the ice making water flowing down from the ice making section into the ice making water tank, and circulates and supplies it to the ice making section again. This is an ice maker that produces ice that does not substantially contain impurities, and depending on the structure of the ice making section, there are vertical plate type, vertical tube type, sloped top flow type, and slope bottom flow type. There are some commonly known names such as , concave flow type, and fountain type. All of these ice makers have in common that in order to freeze the flowing ice making water, the ice making water temporarily goes through a supercooling state below the freezing point, and then freezes. What they have in common is that cotton ice often forms under these conditions. Regarding the phenomenon of the occurrence of cotton ice,
As detailed in No. 15706, cotton ice is produced by supercooled, energetically unstable ice-making water that is affected by external factors (such as vibration, the presence of crystal nuclei such as dust, or temperature distribution, etc.). ), it is thought that this occurs because the ice instantly absorbs the amount of heat equivalent to the latent heat of freezing of the ice, thereby transitioning to a more stable state of cotton ice. Now, as a means for completing the ice-making operation in the water circulation type ice-making machine, a temperature detection means such as a thermostat or a thermistor is provided in the ice-making section to detect the temperature of the ice-making section which decreases as the ice grows. A temperature sensing type is generally used, which completes ice-making operation and shifts to de-icing operation when the temperature drops to . On the other hand, this temperature detection type has its advantages and disadvantages, so for example, as disclosed in Japanese Utility Model Application Publication No. 59-9271, in order to compensate for the disadvantages of temperature detection means, one temperature detection means and one temperature detection means are used. An operation control device has been proposed that can detect ice making and deicing without adjustment throughout the year by using a timer. However, in such an ice maker with only a temperature detection type, and also in an ice maker with both a temperature detection type and a timer type, when cotton ice is generated, the generated cotton ice is everywhere in the ice making water circulation path. Water circulation channels may be blocked. When the ice-making water circulation path is blocked, the ice-making water flowing to the ice-making section stops or becomes extremely low, resulting in no load or extremely light load on the ice-making section, and the temperature of the ice-making section drops rapidly. This decrease in temperature progresses extremely rapidly, and the ice-making completion temperature is reached almost within one minute after the formation of fluff ice.
In other words, the ice-making unit reaches the ice-making completion temperature just before normal ice grows in the ice-making unit, so the temperature detection means described above is activated and the ice-making unit reaches the ice-making completion temperature, even though normal ice has not grown at all. Despite this, the ice making operation ends and the deicing operation begins, resulting in a serious defect. This defective phenomenon will be explained in detail with reference to FIGS. 1 to 6 regarding the conventional ice maker using both a temperature detection type and a timer type described in the above-mentioned Japanese Utility Model Publication No. 59-9271. 1 and 2 show the overall structure of the ice-making machine, and in the figures, an ice-making section 1 is mainly composed of an ice-making chamber 2, a sprinkler 3, and an evaporator 4. Circulation pump installed in ice making water tank 5
The ice-making water supplied from the PM is sprayed into the ice-making compartment 2 via the sprinkler 3, and the ice-making water that has fallen from the ice-making compartment 2 is returned to the ice-making water tank 5 via the gutter 6. During deicing, deicing water is supplied to the ice making tray 9 from a water valve WV connected to an external water supply via a water supply hose 7 and a water supply pipe 8, as shown in FIG. A discharge pipe 10 of the compressor CM is connected to the evaporator 4 via a condenser and a capillary as is well known, and the outlet side of the evaporator 4 is connected to a return pipe 13.
The condenser is connected to the compressor CM via a cooling fan FM, and the condenser is cooled by a cooling fan FM. Furthermore, a solenoid valve HV is provided between one end of the discharge pipe 10 and the evaporator 4.
(See FIG. 3) is provided in a well-known manner, and the ice-making compartment 2 is equipped with a temperature-sensing element Th for detecting the temperature of the ice-making compartment. FIG. 3 shows a control circuit of the operation control device of the ice maker shown in FIGS. 1 and 2, in which a thermal timer TM is connected in series with a thermostat as a temperature sensing element Th. A circulation pump is connected in series to the normally closed contacts A-B of this thermal timerTM.
PM and cooling fan FM are connected, and a solenoid valve HV and water valve WV are connected in series to normally open contacts CD of the thermal timer TM. Both the normally closed contacts A-B and the normally open contacts C-D are configured to turn on after a predetermined delay time (for example, about 180 seconds), and the thermal timer TM starts operating and starts. It is configured so that it does not turn on until about 180 seconds have elapsed even after it enters the state, and it does not turn off until about 180 seconds have passed even after the thermal timer TM stops operating and enters the end state. Next, the operation of the ice maker operation control device shown in FIG. 3 will be described. First, power switch SW
When turned on, compressor CM, circulation pump PM,
The cooling fan FM is activated, the ice making water sent to the ice making compartment 2 is cooled, and ice grows, so that the temperature of the ice making compartment 2 decreases. When the temperature has dropped to the first predetermined temperature (ice making completion temperature), the temperature sensing element Th is activated and the thermal timer TM is turned on (activated) for a predetermined delay time (for example, approximately 180 seconds).
Normally closed contact A of the thermal timer TM
-B is turned off and circulation pump PM and cooling fan
When FM is turned off, normally open contact C-D is turned on, solenoid valve HV and water valve WV are opened, hot gas and deicing water are supplied to ice making section 1, and deicing operation begins. After starting the deicing operation as described above, when the deicing progresses and the ice leaves the ice making compartment 2, the ice making compartment 2
When the temperature rises to the second predetermined temperature (deicing completion temperature), the temperature sensing element Th operates, the thermal timer TM turns off (ends), and a predetermined delay time (approximately 180 seconds) has elapsed. At that point, the normally closed contacts A-B of the thermal timer TM are turned on, the circulation pump PM and the cooling fan FM are turned on, and the normally open contacts C-D are turned off, so that the solenoid valve
The HV and water valve WV are closed, the supply of hot gas and deicing water to the ice making chamber 2 is stopped, and ice making operation resumes. In the control circuit diagram of the operation control device shown in Fig. 3, a thermal timer is used as the timer TM, but this may be a motor timer or an electronic timer, and as described later, when ice fluff occurs, the thermal timer is used. Problems can occur with both motor timers and electronic timers. Figure 4 shows an example of a control circuit using a motor timer. When the thermostat Th reaches a predetermined temperature, contacts 1-3 are turned on and the timer motor TM is rotated by the terminal 3-2 of the timer contact _S1 . , after a predetermined time, a cam plate (not shown) switches contact S ₁ to 2-
1 turns on and the timer motor TM stops. The timer contact _S2 linked to this also turns off at 6-5, stopping the circulation pump PM and cooling fan FM, and at the same time, the contact 6-4 turns on, turning on the solenoid valve HV and water valve WV. thermostat
When it is detected that Th has risen to a predetermined temperature, contacts 1 and 2 are turned on, the timer motor TM is turned on, and after a predetermined time, timer contacts S ₁ and S ₂ are switched. Other operations are the same as for the thermal timer. FIG. 5 shows an example of a control circuit using an electronic timer. The terminals of the electronic timer TM are connected to a power supply line, and the terminals of the timer TM are connected to a thermostat Th. Thermostat Th
When turned on, the timer TM starts operating, and after a predetermined period of time, the relay X built into the timer is operated and the contacts of the relay are switched. Further, after the thermostat Th is turned off, the relay X is turned off after a predetermined period of time has elapsed. Other operations are the same as for the thermal timer. Figure 6 shows how the temperature near the sensor part of the temperature sensing element Th changes over time. In normal ice making operation, the supplied ice making water gradually cools down from point A. It continues to be reduced to about 0
When the temperature drops below ℃, it gradually grows as ice in the ice making compartment 2. When the temperature sensing element Th reaches the first predetermined temperature _T1 (point B), the timer TM operates as described above, and ice making is completed after a predetermined delay time, that is, the ON delay time of the timer TM (point C). ). When deicing starts, the temperature near the temperature sensing element Th rises, and the temperature near the second temperature sensing element Th increases.
When the predetermined temperature T ₂ of
_A1 ). However, if cotton ice is generated during this ice-making operation, as described above, the cotton ice will block the ice-making water circulation path, so the ice-making water may not be supplied to the ice-making chamber 2, or even if it is supplied, it will be extremely slow. As a result, the ice making section is placed under a significantly light load, causing its temperature to drop rapidly. Therefore, it takes only a few minutes to reach the first predetermined temperature T ₁ at point B ₁ from approximately 0° C., and the timer TM is operated without almost normal ice growth. timer
The TM operates in exactly the same way as described above, and reaches the ice-making completion state (point E) after a certain delay time, so the ice-making operation ends with almost no ice growth. Here, regarding the cotton ice, the above-mentioned Special Publication No.
As detailed in the above publication, it is known that the structure is extremely fragile and that it melts in a few minutes and returns to the original ice-making water. Therefore, the supply of ice-making water to the ice-making compartment 2 is stopped or decreased for a few minutes from the generation of cotton ice until it disappears by melting, after which the ice-making water is circulated normally again.
The temperature near the thermosensor Th also decreases to C ₁ as the watering recovers.
The temperature rises from point D to point _D1 , and normal ice-making operation starts again, but since the temperature sensing element Th has already reached the first predetermined temperature _T1 , (Point E), the temperature sensing element Th becomes conductive and stops the ice making operation. Thereafter, the temperature rises to the second predetermined temperature _T2 , the temperature sensing element becomes non-conductive, and the next ice-making operation begins.In this way, the next ice-making operation starts before the previous ice-making operation ends. A serious defect occurs that causes the ice-making operation to start. The above-mentioned methods for eliminating cotton ice include: 1) JP-A-Sho
As described in Publication No. 55-53668, a part of the circulation path is improved to melt cotton ice generated by relatively high temperature ice making water before passing through the ice making section, 2) As described in Japanese Patent Publication No. 58-15706, when a thermostat is used to detect a temperature on the verge of forming cotton ice, a timer is used to temporarily stop the circulation pump motor for a predetermined period of time. 3) Japanese Patent Publication No. 57-142467
Publication No. 58-2574, Utility Model Application No. 58-2575
As described in the above publication, there is a system in which a water retention section is provided in a part of the ice making section, and preliminary ice that becomes ice crystal nuclei is partially grown in this section.

[Problem that the invention attempts to solve]

As mentioned above, in a water circulation ice maker that includes at least a temperature sensing type ice making completion detection means,
When ice fluff occurs, the ice-making completion detection means sometimes malfunctions and shifts from ice-making operation to de-icing operation even though normal ice has not grown, making it difficult to maintain stable ice-making operation. This was not done, and improvements were also requested in terms of ice-making efficiency. In addition, among the above-mentioned methods for eliminating cotton ice, method 1) supplies extra heat to the cotton ice, reducing ice-making efficiency, and requires an extra water circulation circuit, which is extremely dangerous. There was a problem with the product being expensive. Method 2) requires a dedicated thermostat, which is not only expensive but also
Since the motor of the circulation pump must be temporarily stopped during each ice-making cycle, the ice becomes slightly cloudy or has unpleasant unevenness, and furthermore, it is very disadvantageous in terms of ice-making efficiency. This is because the circulation pump motor is always stopped for several minutes during each ice-making operation even if no ice fluff is generated. Furthermore, the method 3) has a problem in that the effect of preventing the formation of cotton ice is not stable, that is, the effect varies depending on the conditions of the ice making water such as water quality, flow rate, water temperature, etc. Furthermore, since the ice-making water is retained in the water retention portion, extra convex portions are formed on the ice, reducing the commercial value of the ice. Therefore, the purpose of the present invention is to solve the above-mentioned methods 1) to 1).
It is an object of the present invention to provide an operation control device for a water circulation type ice making machine that can prevent the malfunction of ice making completion detection and perform stable ice making operation without causing the drawbacks mentioned in (3) above.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention includes an ice-making completion detection means that detects the completion of the ice-making operation and outputs a de-icing operation command signal for causing the ice-making machine to perform the de-icing operation; In the operation control device for a water circulation type ice making machine, the operation control device includes a deicing completion detection means for detecting ice making operation and outputting an ice making operation command signal for causing the ice making machine to perform ice making operation. A predetermined temperature of the ice making section is detected during the ice making operation, which is higher than the completion temperature of the ice making, but lower than 0° C. before the generation of cotton ice, and after a predetermined delay time is detected after the predetermined temperature is detected during the ice making operation. The present invention is characterized by comprising a protection means for outputting a deicing operation command invalidation signal for invalidating the deicing operation command signal outputted by the ice making completion detection means.

[Effect]

The ice-making completion detection means detects the completion of the ice-making operation and outputs a de-icing operation command signal to cause the ice-making machine to perform the de-icing operation, and the ice-making machine is switched from the ice-making operation to the de-icing operation. The deicing completion detection means detects the completion of the deicing operation and outputs an ice making operation command signal to cause the ice maker to perform the ice making operation. In this way, the ice making operation and the ice removal operation are repeatedly performed. During the ice-making operation, the ice-making completion detection means detects the temperature of the ice-making section or the flow rate of ice-making water circulating through the ice-making section. When ice making is completed, the temperature of the ice making section reaches the ice making completion temperature where the ice making operation in the ice making section is substantially completed, and if the flow rate of circulating ice making water is detected, the flow rate almost disappears. . On the other hand, if cotton ice is generated during ice-making operation, the cotton ice blocks the ice-making water circulation path, resulting in almost the same situation as when ice-making is completed. Therefore, without the protective means of the present invention, the ice-making completion detection means would malfunction when cotton ice is generated, causing the ice-making machine to switch from ice-making operation to de-icing operation even though normal ice-making is not being performed. Put it away. However, in the present invention, the protection means is set at the ice-making completion temperature (T ₁ ) at which the ice-making operation is substantially completed in the ice-making section.
Detects a predetermined temperature (T ₃ ) of the ice-making section during ice-making operation, which is higher than 0℃ but lower than 0℃ before cotton ice generation occurs, and after detecting the predetermined temperature (T ₃ ) during ice-making operation. During the predetermined delay time (TD ₃ ), a deicing operation command invalidation signal is output to invalidate the deicing operation command signal outputted by the ice making completion detection means. Even if the ice making operation is performed and cotton ice is generated, the ice maker continues the ice making operation state, and the cotton ice melts and disappears during the delay time (TD ₃ ).

【Example】

Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in which the same reference numerals indicate the same or corresponding parts. First, FIG. 7 shows a control circuit diagram of an operation control device according to an embodiment of the present invention, FIG. 8 is a flowchart for explaining the operation of FIG. 7, and FIG.
This figure is a graph similar to that of FIG. 6, illustrating how the temperature near the sensor portion of the temperature sensing element Th changes over time. Note that the water circulation ice maker in which the operation control device of the present invention is implemented may be the one shown in FIGS. 1 and 2, and in the following description,
Regarding the components of the ice maker itself, the symbols used in connection with FIGS. 1 and 2 are given, but since the symbols are not used in FIGS. Please refer to the figures and FIG. In the embodiment of the present invention, as shown in FIG. 9, the first predetermined temperature T ₁ , that is, the ice-making completion temperature is detected and the timer operation is performed, and the second predetermined temperature T ₂ ,
That is, in addition to detecting the deicing completion temperature and operating the timer, a third temperature is set near the temperature at which fluff ice is generated between the first predetermined temperature _T1 and a temperature below 0°C. The predetermined temperature _T3 is detected during ice making operation and a timer operation is performed. This third
The timer operation upon detecting the predetermined temperature _T3 of
Even if the first predetermined temperature T ₁ is detected after the first predetermined temperature T ₃ is detected during ice-making operation, there is a predetermined delay time.
This is to prevent deicing operation from occurring during TD ₃ . The electronic controller PCB in Figure 7 includes:
As shown in the figure, in response to the temperature signal from the temperature sensing element Th, the above-mentioned first, second and third predetermined temperatures T ₁ ,
a judgment circuit JC that outputs signals representing T ₂ and T ₃ ;
A timer section TM consisting of an ice-making timer TM ₁ , a de-icing timer TM ₂ and a protection timer TM ₃ each operated by output signals representing the first, second and third predetermined temperatures from the judgment circuit JC; Department
A logic circuit section LC connected to the output side of the TM and a relay X operated by the logic output of this logic circuit section LC are built-in. It should be noted that the connection relationship of each component in FIG. 7 is merely an example, and those skilled in the art will be able to use various other circuits or microcomputers to achieve the effects shown in the flowchart of FIG. etc. can be easily thought of. For example, the judgment circuit JC itself may be rendered inoperable for a predetermined delay time using the output of the protection timer _TM3 . In FIGS. 7 and 8, when the power supply or switch SW is turned on (step 101), the deicing operation is started (step 102). That is, the water valve WV and the hot gas valve HV are supplied with power through the normally closed contact C-D of the relay X, and are opened to supply water, and at the same time, send high-temperature, high-pressure gas from the compressor CM to the evaporator 4. The temperature sensing element Th installed in the ice making compartment 2 detects the temperature, and the electronic controller
A judgment circuit JC built into the PCB (Fig. 7) judges whether the temperature is equal to or higher than a second predetermined temperature (deicing completion temperature) _T2 (step 103), and If the temperature is equal to or higher than _T2 , a signal representing the deicing completion temperature is output to the deicing timer _TM2 of the timer section TM (step 104). The de-icing timer TM ₂ operates upon receiving this signal, and when the predetermined delay time TD ₂ set in the timer TM ₂ has elapsed, the de-icing timer TM ₂ activates the relay X built in the electronic controller PCB. An energizing signal (ice making operation command signal) is output, and the contact of relay X is switched to normally open contact A.
-B becomes conductive. As a result, the circulation pump motor PM and fan motor FM are operated to start ice-making operation (step 105), and at the same time, the normally closed contacts C-D become disconnected, so the water valve
Close WV and hot gas valve HV. When the ice-making operation is started, the ice-making chamber 2 is cooled by the cooling device including the compressor CM described above. Cooling progresses during the ice-making operation, and the temperature of the ice-making chamber 2 or the temperature near the temperature sensing element Th reaches the third predetermined temperature.
When T ₃ is reached, the judgment circuit JC built into the electronic controller PCB judges whether or not the temperature is below the third predetermined temperature T ₃ (step 106), and if it is below the third predetermined temperature T ₃ , protection is applied. A signal is issued to energize timer _TM3 (step 107). This protection timer
After TM ₃ is energized, this timer TM ₃ outputs a de-icing operation command invalid signal for a predetermined delay time TD ₃ , so as described above, after that, ice is generated and the temperature sensing element is Even if Th detects a temperature equal to or lower than the first predetermined temperature _T1 , the deicing operation is not started. That is, when cotton ice is generated, the ice making water is not circulated as described above, and the temperature in the ice making chamber 2 rapidly drops from approximately 0°C (point B ₃ in Figure 9), and the temperature reaches the third predetermined temperature. The protection timer TM ₃ starts operating at the temperature T ₃ (point B ₂ in FIG. 9), and the third delay time of the protection timer TM ₃ starts.
The first predetermined temperature T ₁ is reached during TD ₃ (point B ₁ in FIG. 9). Even if the first predetermined temperature T ₁ is reached during this third delay time TD ₃ , ice making is not completed, so the ice making operation continues, and when the cotton ice melts naturally after a short period of time, The ice-making water is again circulated, the temperature of the ice-making chamber 2 rises, and normal ice-making operation resumes from the point _D1 shown in FIG. After the protection timer TM ₃ times up, the judgment circuit JC built into the electronic controller PCB will
It is determined whether the temperature of the temperature sensing element Th has decreased to the first predetermined temperature, that is, the ice-making completion temperature _T1 (step 108), and when it is determined that the temperature has decreased to the first predetermined temperature _T1 , the ice-making timer _TM1 is activated. A signal indicating the ice making completion temperature is output (step 109). The ice making timer operates upon receiving this signal, and when the first delay time TD ₁ elapses and the ice making timer TM ₁ times out,
Outputs a signal (de-icing operation command signal) to de-energize relay X built into the electronic controller PCB. When relay X is deenergized, normally open contacts A-B are open,
Normally closed contacts C-D are closed, and the pump motor
Stop the operation of PM and fan motor FM, open hot gas valve HV and water valve WV, and start deicing operation. Here, to give an overview of the various temperature and time setting values, the first predetermined temperature _T1 detects the temperature that triggers the ice-making completion state, so it is usually set at -10℃ to -15℃, and the ice-making timer The first delay time TD ₁ to which TM ₁ is set is approximately 3 to 10 minutes. First predetermined temperature T ₁ and ice making timer TM ₁
There is a close relationship with , and the appropriate value is taken depending on the characteristics of each machine. The second predetermined temperature _T2 is a temperature that triggers the completion of deicing, and is usually set at about 5°C to 10°C,
Also, it is appropriate for the de-icing timer TM ₂ to be around 1 minute. The third predetermined temperature T ₃ is set to a temperature between the first predetermined temperature T ₁ and approximately 0° C. before the formation of cotton ice, and is usually suitably about -5° C. to 10° C. Third delay time set by protection timer TM ₃
TD ₃ must cover sufficient time from the generation of cotton ice until it melts, and at the time the temperature in the ice making chamber 2 reaches the first predetermined temperature _T1 , that is, the ice making completion temperature. It should not be so long that it ends up being: Considering that such cotton ice usually goes from generation to melting in about 3 minutes, about 5 to 10 minutes is appropriate. However, the values shown above are merely examples, and various values should be selected depending on the characteristics of the machine used. 10, 10A, 11, and 12 show an embodiment in which the present invention is applied to an ice maker having another ice making completion means, and FIG. 10 shows the entire ice maker. 10A is a structural diagram shown in FIG.
1 is a control circuit diagram of the operation control device for the ice maker shown in FIG. 10, and FIG. 12 is a flowchart for explaining the operation of the control circuit shown in FIG. 11. In this embodiment, as a means for detecting the completion of ice making, the ice making water circulation path is
A flow sensor FS shown in diagram 0A is installed. As the ice-making water in the ice-making water tank 5 grows as ice in the ice-making compartment 2 as ice-making progresses, the water level in the ice-making water tank 5 gradually decreases from B to A, and the time point when the water level reaches A. Now, the circulation pump motor
The water level at the PM suction port becomes below PM1, and the motor
PM can no longer absorb water.
The flow rate sensor FS installed in the ice making water circulation path is
It detects that the circulating flow has run out and turns off, completing ice making. The ice making completion detection means, that is, the flow rate sensor FS is the reed switch 16.
It consists of a magnet 17, a valve body 18 that carries the magnet 17 and swings in the ice-making water circulation path, and a support shaft 19 of the valve body 18, and water circulates in the ice-making water circulation path. At times, the valve body 18 is pushed up by the water pressure, and the magnet 17 approaches the reed switch 16, closing the electric circuit. On the other hand, when water is not circulating, the valve body 18 swings downward due to the weight of the valve body 18 and the magnet 17, thereby opening the electric circuit (ice making completed state). Even in an ice maker with such a configuration, if cotton ice is generated, the ice making water circulation path is similarly blocked, so there is no circulating flow, and the flow rate sensor FS outputs a signal indicating that ice making has been completed. However, if the protection timer TM ₃ in the present invention is provided as in the previous embodiment (FIG. 11), during the third delay time TD ₃ ,
Disable the signal from flow sensor FS and
If the delay time TD ₃ of the protection timer TM 3 is selected so that when the protection timer TM ₃ times up in step ₂₀₇ of FIG. Completely preventable. Although the present invention has been described above with reference to two embodiments thereof, the present invention is not limited to the type of ice making machine shown in the embodiments, and generally the ice making operation is completed when fluff ice is generated. The present invention can be applied to ice makers that are stored away.

[Effect of the idea]

According to the present invention, a predetermined temperature of the ice making section is detected during the ice making operation, which is higher than the ice making completion temperature at which the ice making operation is substantially completed in the ice making section, but lower than 0° C. before the generation of fluff ice. During the predetermined delay time after detecting during ice-making operation, the ice-making completion detection means outputs a de-icing operation command invalidation signal to invalidate the de-icing operation command signal outputted, so that the ice-making water reaches 0°C. Even if fluff ice is cooled below the ice-making temperature and exhibits the same situation as ice-making completion, the ice-making completion detection means will not malfunction and switch to de-icing operation, making it possible to perform stable ice-making operation. This will improve ice making efficiency. Moreover, in this invention, even if cotton ice is generated during ice-making operation, the ice-making operation is continued and waits for the cotton ice to naturally melt during a predetermined delay time, which is different from conventional technology. Method 1)
As in method 2, the ice making water is supplied to the cotton ice before it passes through the ice making section to reduce ice making efficiency, or as in method 2), the circulation pump motor is temporarily stopped during each ice making operation to reduce the ice making efficiency. As with method 3, the results may be affected by the conditions of the ice making water such as water quality, flow rate, water temperature, etc., and the ice may have convexities. It is possible to produce smooth, transparent, and high-quality ice without any ice floes being produced, and there is no loss of ice-making capacity since normal ice-making operation is only performed when no ice fluff is generated. Furthermore, according to the embodiment of the present invention, when applying the embodiment to an ice maker already in use, what is added to the conventional electronic controller is a third predetermined temperature control.
Judgment circuit JC and protection timer to judge T ₃
TM ₃ , it is a very inexpensive upgrade to a conventional ice maker.

[Brief explanation of drawings]

Figures 1 to 6 explain a conventional ice maker. Figure 1 is a sectional view showing the overall structure of the ice maker, and Figure 2 is an enlarged view of the main parts of the ice maker shown in Figure 1. , Fig. 3, Fig. 4, and Fig. 5 are control circuit diagrams showing various operation control devices of conventional ice making machines. Fig. 6 is a waveform diagram for explaining the drawbacks of the conventional ice making machine. The relationship between the temperature of the ice making room and time at the time of occurrence is shown. 7 to 9 illustrate an embodiment of the present invention,
FIG. 7 is a control circuit diagram showing the operation control device of the ice maker, FIG. 8 is a flowchart for explaining the operation of the control circuit in FIG. 7, and FIG. To explain the operation of the embodiment shown in
Waveform diagrams similar to FIG. 6 and FIGS. 10 to 12 are as follows:
10 is a cross-sectional view showing the overall structure of the ice making machine, and FIG. 10A is an enlarged view of the area indicated by the reference numeral 10A in FIG. 10. , FIG. 11 is a control circuit diagram showing an operation control device for an ice making machine, and FIG. 12 is a flowchart for explaining the operation of the control circuit shown in FIG. 1... Ice making unit, Th... Temperature sensing element, JC... Judgment circuit, TM ₁ ... Ice making completion detection means (ice making timer), TM ₂ ... Deicing completion detection means (deicing timer),
TM ₃ ...Protective means (protection timer), FS...Ice making completion detection means (flow rate sensor), _T1 ...First predetermined temperature (ice making completion temperature), _T2 ...Second predetermined temperature (deicing temperature) completion temperature), T ₃ ... third predetermined temperature lower than 0° C., TD ₃ ... predetermined delay time.

Claims (1)

[Scope of claim for utility model registration] Ice-making completion detection means (Th, JC, TM ₁ , FS) that detects the completion of ice-making operation and outputs a de-icing operation command signal to cause the ice-making machine to perform de-icing operation. , a water circulation type ice maker comprising a deicing completion detection means (Th, JC, TM ₂ ) that detects the completion of the deicing operation and outputs an ice making operation command signal for causing the ice maker to perform the ice making operation. In the operation control device, the predetermined temperature (T ₃ ) of the ice making unit 1 is higher than the ice making completion temperature (T ₁ ) at which the ice making operation in the ice making unit 1 is substantially completed, but lower than 0° C. before the generation of cotton ice.
is detected during the ice-making operation, and the ice-making completion detection means outputs the de-icing operation command signal for a predetermined delay time (TD ₃ ) after the predetermined temperature (T ₃ ) is detected during the ice-making operation. Protective means (Th, JC,
TM ₃ ) An operation control device for a water circulation ice maker, characterized by: