JPS5934942B2 - Fully automatic ice making control device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fully automatic ice-making control device for an ice-making machine, and in particular, a temperature-sensing element for detecting the temperature of a cooler and a temperature-sensing element for correcting outside temperature are connected to a control circuit. , Under the action of these temperature sensing elements, ice making and ice removal operations are achieved that are completely unaffected by changes in outside temperature throughout the year, and the control circuit can easily and easily implement all the functions required by the ice maker. This invention relates to a fully automatic ice-making control device that achieves complete automation by providing it in an inexpensive manner.

In recent years, various types of automatic ice making have been introduced, whether for consumer or commercial use, to produce large amounts of ice exclusively for consumption, to add to food and drink, or to use for medical aid purposes. Although automatic ice making machines have come to be widely used, a detailed study of the mechanisms that make up this automatic ice making machine reveals that there are still many problems that remain unimproved.

For example, timers and gas-filled thermostats are widely used to control the completion of ice making, which detects when a certain amount of ice has been produced and stops the operation of the ice making mechanism, but none of these devices can be used outside of the four seasons. Since the refrigeration capacity changes with changes in air and water temperature, the user must adjust these settings according to changes in the outside temperature, while if the settings are not adjusted, the ice formation will be different. Not only does ice growth become incomplete, which causes problems when using ice, but in the worst case scenario, the ice grows too much and the so-called water tray and ice-making compartment become jammed, causing damage to mechanical parts. There is a risk of damage.

In addition, when the water tray is tilted away from the ice maker to collect ice from the ice maker and then returned to its original position, the ice that is stuck to the water tray causes ice to get stuck. Therefore, it is necessary to sprinkle ice-melting water into the water tray to ensure that the frozen ice melts, but in order to do so, it is necessary to reduce the amount of ice-melting water sprinkled due to the unstable operation of the ice-making completion control due to the outside temperature mentioned above. It is necessary to set up a large number of outlets, which poses a problem from the standpoint of water conservation.

In order to solve this problem of ice-making completion control, there has recently been a method of storing various conditions of the ice-making machine in a microcomputer and automatically operating the ice-making machine according to these conditions. This method is based on experimental data, and since the ice-making machine itself has large deviations and various corrections are required for each individual ice-making machine, it is not desirable from an economic standpoint or for mass production.

In addition, gas-filled thermostats are often used for ice removal completion control, which detects the completion of ice removal and moves on to the next ice-making operation, but it is affected by the outside temperature, or ambient temperature, and does not operate particularly well in winter. If you neglect to readjust the settings, in the worst case, the de-icing completion will not be detected and a large amount of the ice-melting water mentioned above will flow, causing problems in conserving water resources. Not only is this a problem, but it also causes problems such as not being able to make ice because the next ice making operation does not start.

In addition, it is necessary to select a mounting location where the temperature of the tongue body and the capillary is higher than the set temperature of the gas-filled thermostat for detecting the completion of ice removal, which is a major design limitation.

Recently, a cord heater has been attached to the tongue body or the capillary, and a bimetal thermostat has been attached in series with it, so that when the temperature gets low, the heater is also energized to avoid the above-mentioned problem, but the number of attached parts has increased. This is not desirable for mass production because it is expensive and the number of assembly points increases.

Furthermore, when the gas-filled thermostat is used for so-called water storage completion control, which stops the operation of the ice maker when the ice in the water storage is full, it is affected by the ambient temperature as described above, especially at low temperatures. If the temperature drops below 5°C, the ice maker will not work even after resetting the settings. It had to be started and stopped manually.

Recently, a cord heater and a bimetallic thermostat have been used to compensate for low temperatures.
As in the case of the above-mentioned ice-off completion control, the number of attached parts and assembly increases, which is unfavorable in terms of cost and mass production.

Furthermore, there is a system that uses a mechanical switch to control the completion of water storage, and although this solves the above-mentioned problems, there is also a problem with the water storage completion control itself, when the switch closes during ice making operation and the water storage is completed. In case of control,
Residual water in the water system, including the ice-making water tank, may freeze, causing damage to mechanical parts, and when ice-making operation is resumed, ice-making will begin with water that has been left in the ice-making water tank for a long time. Particularly in the summer, it is unsanitary, and there are problems in that the water system is prone to stains such as water scale.

The problem that occurs during power outages is that when the power is restored, the ice maker performs double ice making operation, and the extremely grown ice can cause destruction or damage to parts around the mechanism. There are ice-making operations using a timer, but the mechanism is complicated, expensive, and has a high failure rate.

Also, if there is a somewhat prolonged power outage, a frame may form during the first ice-making cycle.

A problem with ice makers that use water-cooled condensers is that during the winter in cold regions, when the ice maker is stopped, residual water freezes inside the condenser, causing it to burst and become irreparable. For this reason, commercially available heaters and the like are generally installed, but there are various problems with their effective use from the standpoint of safety and power consumption.

In addition, in order to start the ice maker at the time of installation, or to resume operation after storing the water tray in the raised position for a long period of time, a manual reset switch is generally provided, and the water tray can be reset by pressing the switch. The ice making water is forcibly lowered to supply ice making water, but this requires manual operation.
It would be preferable if automation could be realized in this regard as well.

Furthermore, if the ice maker is operated at extremely high temperatures or the condenser becomes extremely dirty, the pressure in the refrigeration circuit may rise abnormally and the refrigeration capacity may drop significantly, resulting in longer ice-making operation times. Furthermore, in extreme cases, problems such as ice-making operation continuing without stopping may result in damage to the ice-making machine. The reality is that little consideration has been given to this.

In addition, in the case of water-cooled condensers, it is common to use an automatic water supply valve that operates based on condensation pressure to control the water flowing into the condenser. ,
Due to turbulent corrosion, the valve may operate in an open state, consuming a large amount of wasted water, a problem that users often only notice when collecting their water bill, and no measures have been taken to address this issue. is the current situation.

The individual current problems have been explained in detail above, but an ice-making control device that solves all of these problems can be created at low cost without using expensive microcontrollers, etc., and can be easily integrated into a single control circuit. It would be very desirable if it could be configured for mass production.

The present invention has been made in view of the above points, and includes an ice making mechanism including a refrigeration circuit, a water storage, and an ice making mechanism drive circuit that energizes the refrigeration circuit. In the ice maker, the ice-making operation and the ice-removing operation of the refrigeration circuit are controlled by a control circuit, and the control circuit detects the temperature of a portion where changes in refrigeration capacity due to outside temperature can be detected and determines the ice-making completion temperature. The ice-making completion control signal is output by inputting both signals from the first temperature detector which outputs a reference signal representing the temperature of the cooler and the second temperature detector which detects the temperature of the cooler and comparing these two signals. a first operational amplifier; a second operational amplifier that inputs a signal from the second temperature detector and a reference signal representing the ice melting water sprinkling start temperature and outputs an ice melting water sprinkling start control signal; a third operational amplifier which receives a signal from the temperature detector and a reference signal representing the ice-off completion temperature and outputs an ice-off completion control signal; Under the action of a switching device energized by a control signal, when the temperature of the cooler reaches the ice-making completion temperature, the ice-making operation is terminated and the ice-removing operation is started;
When the cooler temperature reaches the ice-melting water sprinkling start temperature, the sprinkling of ice-melting water is started, and when the cooler temperature reaches the ice-removing completion temperature, the ice-removing operation is ended and the next ice-making operation is started. It is an object of the present invention to provide a fully automatic ice-making control device that controls the ice-making mechanism drive circuit so that the ice-making mechanism is turned on.

Other objects and advantages of the invention will become more apparent from the detailed description below.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an example of the refrigeration circuit of an ice maker to which the present invention is applied. At the top of a water storage 1, an ice making water tank 3 is installed which is rotatable together with a water tray 2. The ice-making water tank 3 is in the raised position shown in the diagram during ice-making operation, and is in the lowered position during ice-removal operation with a water tray,
It is driven by a drive motor AM.

A changeover switch is mounted in conjunction with the motor AM to detect the position of the tank 3.

The cooler 5 is disposed above the water tray 2 and has a large number of small chambers 5a having open ends at the bottom and an evaporator 5b.

The open end of the small chamber 5a is closed by the water tray 2 which is in the raised position during ice-making operation, and the circulation pump 6 pumps the ice-making water in the ice-making water tank 3 to the water tray 2, and further transfers the ice-making water to the water tray. The water is circulated and supplied to each small chamber 5a through a small hole provided in 2 in the form of a fountain.

A cooler temperature detector 5c is installed in the cooler 5 to detect the temperature of the cooler in order to control the ice making and ice removal operations of the ice maker.

During the ice-making operation, the high-temperature, high-pressure refrigerant gas compressed by the compressor CM passes through the refrigerant passage 7 shown by the thick solid line in the direction of the arrow, passes through the refrigerant pipe 8b of the condenser 8, which exchanges heat with the cooling water pipe 8a, It is cooled and liquefied in the condenser 8, and then sent to the evaporator 5b through an expansion means 9.

The liquefied refrigerant gas evaporates while passing through the evaporator 5b.
After removing heat corresponding to the heat of evaporation from the refrigerant, the refrigerant returns to the compressor CM through the refrigerant passage 7'.

A condenser temperature detector 10 is provided at the outlet of the condenser 8 to set the ice-making completion temperature.

When the ice-making operation continues and ice grows sufficiently in the small chamber 5a, the cooler temperature detector 5c detects the ice-making completion temperature set by the condenser temperature detector 10, and the ice-removing operation begins.

That is, the water tray drive motor AM is driven to lower the water tray 2 and the ice-making water tank 3, and at the lowered position, the water tray drive motor A is driven.
When M kicks the changeover switch and stops, the bypass passage γ
The hot gas valve HGV provided therein is opened, and the high-temperature, high-pressure refrigerant gas from the compressor CM is directly sent to the evaporator 5b via the bypass passage 7 to heat the cooler 5.

When the temperature of the cooler 5 rises and the ice cubes in the small chamber 5a break off and fall into the ice storage 1, the temperature of the cooler 5 rapidly rises and reaches the ice-melting water sprinkling start temperature.

When the cooler temperature detector 5c detects the ice melting water sprinkling start temperature, the electromagnetic water supply valve Wv provided in the supply pipe 8c branching from the cooling water pipe 8a connected to the water supply port 11 opens, and the water tray 2 Ice-melting water is introduced to melt the burred ice, and this ice-melting water is further stored in the ice-making water tank 3 as ice-making water for the next ice-making operation.

At the time when the melting of the frozen ice is completed, the temperature of the cooler 5 has further increased to reach the ice removal completion temperature, and the cooler temperature detector 5c detects this and starts the next ice making operation.

Note that the cooling water pipe 8a is provided with an automatic water supply valve 12 at a position downstream of the condenser 8, and controls the flow rate of cooling water, that is, condensed water, passing through the pipe 8a in response to the condensing pressure or the condensing temperature.

A condensed water outlet temperature detector 13 is further installed downstream of the cooling water pipe 8a to detect the condensed water outlet temperature, and to prevent the condensed water from freezing in the condenser 8. An antifreeze heater H is provided in the condenser 8 for this purpose.

Further, a mechanical water storage switch 14 for stopping the ice making operation when a predetermined amount of ice is stored in the water storage 1 is installed in the water storage 1.
is placed at a predetermined position.

FIG. 2 shows an ice-making mechanism drive circuit for operating the ice-making machine shown in FIG. A control circuit 20 that performs the following is shown in block form.

The ice making mechanism drive circuit connects a power supply introduced at a commercial frequency via a power switch SW to a compressor CM, a circulation pump motor PM that drives the circulation pump 6 (Fig. 1), a water tray drive motor AM, and an electromagnetic water supply. Valve Wv, hot gas valve HGV and antifreeze heater H are connected in parallel,
These are each connected in series with the contacts of a relay controlled by a control circuit 20.

Further, the electromagnetic water supply valve W■, the hot gas valve HGV, and the circulation pump morph PM are configured to be selectively energized by the first switch part 4a of the changeover switch 4 that rotates the water dish drive motor AM in forward and reverse directions. ing.

The details of the control circuit 20 that controls the ice-making mechanism drive circuit shown in FIG. 2 are shown within the dotted line box in FIG. A second switch of the changeover switch interlocks with the condensed water outlet temperature detector 13, the condenser temperature detector 10, the cooler temperature detector 5c, and the first switch part 4a so as to input various signals in connection with the 4b and the water storage switch 14 are connected, and on the right side there are an abnormality alarm buzzer 21, an abnormal condensed water indicator light 22, a refrigeration circuit abnormality indicator light 23, and a time display part to display various operating states of the ice maker. 24, an ice making indicator light 25, an ice removal indicator light 26, and an ice storage indicator light 27 are connected as appropriate.

A condenser temperature detector 10 that outputs a reference voltage Vs representing the ice-making completion temperature is connected to one input terminal of a first operational amplifier 31 that detects the ice-making completion temperature and outputs a °1'' signal. A cooler temperature detector 5c outputting a voltage .times.5 (FIG. 1) representing a temperature of 5 (FIG. 1) is connected to the other input terminal of the first operational amplifier 31.

The output of the cooler temperature detector 5c is also connected to a second operational amplifier 32 which detects the ice-making water sprinkling start temperature and outputs a "1'" signal.
The other input terminal of the amplifier 32 is connected to the variable resistor R2.

This variable resistor (R2) is used to set a reference voltage r2 representing the ice melting water sprinkling start temperature for each ice maker during mass production.

The output of the cooler temperature detector 5c is further connected to one input terminal of a third operational amplifier 33 that detects the ice removal completion temperature and outputs a "0" signal, and the other input terminal of the amplifier 33 is connected to a variable resistor. ■ Connected to R3.

The role of this variable resistor ■R3 is the same as that of resistor ■R2.
The objective is to set a reference voltage r3 representing the ice removal completion temperature for each ice maker during mass production.

The mechanical water storage switch 14 is connected to one input terminal of a NOR circuit 36 via a delay circuit 34 and an inversion circuit 35.
The other input terminal of the NOR circuit 36 is connected to a contact U of the second switch section 4b, which is closed when the water tray is in the raised position.

The output of the NOR circuit 36 is also connected to the first relay, that is, the ice storage detection relay X1, which is energized when water storage is completed, the ice storage indicator light 27, and the NOR circuits 37 and 38.

The input terminal of the counter 39 for setting the specified maximum time of the ice-making operation is connected to an oscillator 40 that oscillates clock pulses in order to measure the elapsed time of the ice-making operation, and the terminal T that outputs pulses is used to display the elapsed time. time display section 24
Terminal R is connected to the terminal R and is used to reset the time measurement of the counter 39 upon receiving the "1" signal during ice removal operation.
Second switch part 4b that closes when the water tray is in the lowered position
The output terminal P is connected to the contact d of the OR circuit 41.
It is connected to an abnormality alarm buzzer 21 via the refrigeration circuit abnormality indicator light 23.

The input of the OR circuit 42 is connected to the first operational amplifier 31, the counter 39, the automatic reset circuit 43, and the output of the NOR circuit 36, and the output of the OR circuit 42 is connected to the first flip-flops F, F, and the 27th flip-flop. Flop F
, F2 are connected to the respective terminals.

The Q terminals and the circuit terminals of the first flip-flops F, F1 are connected to the inputs of NOR circuits 38 and 37, respectively;
The output of the Noah circuit 37 is connected to the ice-making indicator light 25, and the output of the Noah circuit 38 is connected to a second relay, that is, a driving command relay X2, which is energized during ice-off operation, and an ice-off indicator light 26.

The contact d of the second switch section 4b is connected to the J terminal of the second flip-flop F, F2, and the sub-terminal is connected to the NOR circuit 4.
The other input of the NOR circuit 44 is connected to the output of the third operational amplifier 33.

The output of the NOR circuit 44 is the 17th lip-flop F,
Connected to the J terminal of Fl.

Note that the OR circuit 42, the flip-flops F-F1 and F-F2, and the NOR circuit 44 constitute a holding circuit for holding the signals from the first and third operational amplifiers.

The output of the second operational amplifier 32 is connected to a third relay, ie, a water supply valve relay X3, for energizing the electromagnetic water supply valve W⊙ when the cooler 5 reaches the ice melting water sprinkling start temperature.

The output of the condensed water outlet temperature detector 13 is connected to one input of the fourth operational amplifier 50 which detects the abnormal temperature of the condensed water and outputs the "1" signal, and the other input of the amplifier 50 is connected to the It is connected to a variable resistor R4 for setting a reference voltage r4 representing abnormal temperature.

The output of the amplifier 50 is sent to an abnormality alarm buzzer via an OR circuit 41.
21 and is also connected to an abnormal condensed water indicator light 22.

The output of the detector 13 is further connected to one input of a fifth operational amplifier 51 which detects the freezing temperature of the condensed water and outputs a signal '1'. It is connected to a variable resistor VR5 for setting a reference voltage r, which represents the temperature.

The output of the amplifier 51 is the fourth one that enables the heater H to be energized.
It is connected to a relay, that is, a heater relay X4.

The operation of the fully automatic ice making control device according to the present invention configured as described above will be explained in detail below.

When the power switch SW is closed or the power outage is restored, ice removal operation is immediately started.

That is, when power is supplied to the ice making mechanism drive circuit including the compressor CM and the control circuit 20, the automatic reset circuit 43 in the control circuit 20 resets the ``1'' to start the ice removal operation.
A signal is output for a certain period of time, and the signal is applied to the terminals of the first and second flip-flops F, Fl and F, F2 through an OR circuit 42, respectively.

Thereby the first and second flip-flops F,
Since Fl, F, and F2 are maintained in the illustrated state,
The NOR circuit 38 inputs the "0" signal (first holding signal) from the Q terminals of the first flip-flops F and Fl, outputs the "1" signal, turns on the deicing indicator 26, and switches on the second relay X2. to support.

When the second relay X2 is energized, its normally closed contact
2b and X2b' are opened, and normally open contact X2a is closed (FIG. 2).

When the water tray 2 (Fig. 1) is in the raised position as in the case of power outage recovery, the water tray drive motor AM is energized via the contact U of the first switch section 4a, and the water tray 2 is placed in the lowered position. At this point, the switch section 4a is switched to the contact point d and the operation is stopped.

As a result, the hot gas valve HGV is energized and opened to start heating the cooler 5, and at the same time, the counter 39 time measurement is reset.

The signal from the contact d of the switch section 4b is also applied to the J terminals of the second flip-flops F and F2, and is applied to the 27th flip-flop.
Invert flops F and F2.

When the temperature of the cooler 5 rises and the output voltage vT from the cooler temperature detector 5c reaches the voltage indicating that the ice has taken off from the water, that is, the reference voltage r2 representing the ice melting water sprinkling start temperature,
The second operational amplifier 32 outputs a "1" signal to energize the third relay X3.

When the third relay X3 is energized, its normally open contact X3a closes, and when the electromagnetic water supply valve W is energized, it opens.
Melted ice water is sprinkled into the water tray 2.

The temperature of the cooler 5 further increases and the cooler temperature detector 5c
When the output voltage vT from the third operational amplifier 33 reaches the reference voltage r3 representing the ice removal completion temperature, the third operational amplifier 33 outputs a "0" signal to the NOR circuit 44.

The NOR circuit 44 inputs the 0'' signal from the third operational amplifier 33 as well as the 0'' signal from the circuit terminal of the second flip-flop, and outputs a +11 I+ signal to the J terminal of the 17th flip-flop F and Fl. , thereby inverting the first flip-flops F and Fl.

(At this stage, the first and second flip-flops F,
F, and F, F2 are both held in the opposite state as shown.

) The NOR circuit 37 includes the first flip-flops F and Fl.
By inputting the ``0'' signal from the terminal circuit and outputting the ``1'' signal, the ice-making indicator light is turned on.

Further, the NOR circuit 38 includes the 17th lip-flop F, F.

By inputting the "1" signal (second hold signal) from the terminal Q of the controller and outputting the "0" signal, the ice-off indicator light 26 is turned off and the second relay X2 is de-energized. End ice operation.

When the second relay X2 is deenergized, its normally open contact X2a is opened, and its normally closed contacts X2b and X2b are also closed, so the water tray drive motor AM is driven and the water tray 2 is raised.

When the water tray drive motor AM turns on the changeover switch 4 when the water tray 2 is in the raised position, the switch parts 4a and 4b fall toward the contact point U, and the motor AM stops.

Thereby the hot gas valve HGV and the electromagnetic water valve W■
At the same time, the circulation pump motor PM is energized, thereby starting the ice-making operation.

At the same time, the reset signal to the terminal R of the counter 39 is canceled because the 1p signal from the contact d of the second switch section 4b disappears, and the measurement of the elapsed time of the ice-making operation is started, and the time display section 24 The elapsed time is displayed.

When the ice-making operation continues and ice grows sufficiently in the small chamber 5a of the cooler 5, and the temperature of the cooler 5 reaches the ice-making completion temperature, the output voltage vT from the cooler temperature detector 5c changes to the condenser temperature detector. When the reference voltage s representing the ice-making completion temperature from 10 is reached, the first operational amplifier 31 outputs a signal ``1'', which passes through the OR circuit 42 to the first and second flip-flops F, Fl and F, F2. Invert each to the state shown.

As a result, the ice-making indicator light 25 goes out, the ice-removing indicator light 26 lights up, and the second relay is energized, returning to the initial ice-removing operation for removing ice from the ice cubes in the small chamber 5a.

Refrigeration capacity can be significantly reduced if the ice maker is operated at extremely high temperatures, if liquid backs up, gas leaks, or if the condenser becomes extremely dirty and the pressure in the refrigeration circuit increases abnormally.

When such an abnormality occurs in the refrigeration circuit, it takes a long time for the temperature of the cooler 5 to reach the ice-making completion temperature, or it becomes impossible to reach the temperature.

The counter 39 outputs a "1" signal from the terminal P to the OR circuit 42 if ice making is not completed by the preset maximum time, that is, if a reset signal is not input to the terminal R by that time. When the ice making operation is completed, the abnormality alarm buzzer 21 sounds and the refrigeration circuit abnormality indicator light 23 is activated.
lights up.

Such an abnormality display/alarm informs the user of the abnormality, so that the user can take precautions before it develops into a major problem such as an unrepairable problem.

When the ice-making operation is repeated and a predetermined amount of ice is stored in the water storage 1, the mechanical water storage switch 14 closes, and the delay circuit 3 closes.
4 and the signal inversion circuit 35 to the NOR circuit 36.
give a signal.

The mechanical water storage switch 14 is, for example, disclosed in Japanese Patent Application Laid-Open No. 51-126.
It is equivalent to the one shown in Publication No. 553, and is good because it does not operate unstable like when a gas-filled thermostat is used as this type of switch, but it is only mechanical. When taking off and falling, the switch may be momentarily closed due to contact with ice.

The delay circuit 34 is provided to avoid this problem, and provides a "0" signal to the NOR circuit 36 only when the switch 14 is continuously closed for a predetermined period of time.

During ice removal operation, when the water tray is in the lowered position, press switch 1.
4 is closed for a predetermined period of time, the NOR circuit 36 also receives the "0" signal from the contact U of the switch section 4b, so the I
+111 signal is output.

This "1" signal is given to the OR circuit 42 and also to the NOR circuits 37 and 38 to inhibit each circuit, and further energizes the first relay X and also energizes the water storage indicator light 2.
Turn on 7.

When the first relay X1 is energized, its normally open contact X1a is closed, and its normally closed contact X1b is opened to cut off the power to the ice making mechanism drive circuit including the compressor CM.

The water storage operation described above is not performed when the water tray is in the raised position during the ice-making operation because the NOR circuit 36 receives the "'1" signal from the contact U of the second switch portion 4b.

When the ice in the water storage tank 1 is used up and decreases below a predetermined amount, the water storage switch 14 opens to release the inhibition of each circuit, and the second
Relay X2 is energized and the ice-off indicator light is turned on, and since the changeover switches 4a and 4b are tilted toward contact point d, the hot gas valve HGV is energized and ice-off operation is started.

The automatic water supply valve 12 (Fig. 1), which controls the flow rate of condensed water in a water-cooled condenser, may operate in an open state due to debris clogging or turbulent corrosion, allowing a large amount of condensed water to flow. If such a failure occurs in the automatic water supply valve 12, the temperature of the condenser will drop considerably compared to normal conditions.

The condensed water outlet temperature detector 13 detects the temperature at the condenser outlet and outputs a detection voltage corresponding to the temperature, and the fourth operational amplifier 50 compares the detected voltage with a reference voltage r4 representing the abnormal temperature of the condensed water. do.

Then, the automatic water supply valve becomes defective and the detected voltage is reduced to the reference voltage r.
When the temperature drops below 4, the fourth operational amplifier 50 outputs a signal "1", which causes the abnormality alarm buzzer 21 to sound and the abnormal condensed water indicator lamp 22 to light up.

In addition, during the winter, when the ice maker is stopped due to the completion of water storage,
The condensed water may freeze, but in order to prevent this, the fifth operational amplifier 51 converts the detected voltage from the condensed water outlet temperature detector 13 into a reference voltage r5 representing the freezing temperature of the condensed water.
When the detection voltage drops below the reference voltage r5,
1'' signal is output to energize the fourth relay X4.

When the fourth relay X4 is energized, its normally open contact X4a is closed, but if the normally open contact X1a of the first relay X1, which closes when water storage is completed, is closed, the antifreeze heater H is energized. to prevent condensate from freezing.

Next, the ice-making operation completion control applied to the present invention will be explained.

In FIG. 3, the circuit unit that performs ice-making completion control is a condenser temperature detector 10 that provides an input signal to the first operational amplifier 31.
Although the circuit is simply shown with the cooler temperature detector 5c blank, there is one shown in FIG. 4 as an example of a specific circuit.

In Fig. 4, the condenser temperature is detected by connecting a correction resistor Rc in parallel to the negative thermistor TH4 associated with the temperature sensing element installed in the condenser 8, and connecting a variable resistor VR in series with both. A container 10 is configured.

A contact of the variable resistor VR1 is connected to one input of the first operational amplifier 31, and the upper part of the variable resistor with respect to the contact is defined as a resistor R1, and the lower part thereof as a resistor R2.

The other end of resistor R1 is connected to power supply B+.

Note that the variable resistor VR0 is used to set the reference voltage Vs for each ice maker during mass production.

Further, a cooler temperature detector 5c is configured by connecting a resistor R3 in series to a negative thermistor TH2 associated with a temperature sensing element installed in the cooler 5.

The connection point between thermistor TH2 and resistor R3 is connected to the other input of amplifier 31, and the other end of resistor R3 is connected to power supply B+.
connected to.

With the above configuration, the reference voltage Vs and the cooling temperature detection voltage vT are given by the following equations.

R2+Ry THL-Re■s=□
However, RV-□ R1+R2+RV TH1+R.

H2 vT-□ R3+TH2 Therefore, the first operational amplifier 31 sends an ice-making completion signal to the Schmitt circuit 42 when the detection voltage ■T becomes larger than the reference voltage ■s.

If the reference voltage (8) representing the ice-making completion temperature is set to a constant value, ice-making will be completed at a certain temperature of the cooler 5, which will be affected by the outside temperature, and when the outside temperature is low, it will take one ice-making operation. As the time becomes shorter, problems arise such as insufficient ice growth.

The condenser temperature detector 13 for setting the reference voltage (8) is provided to overcome the above-mentioned problem and is set to produce constant ice throughout the four seasons.

In other words, the temperature sensing element related to the negative thermistor TH1,
In this embodiment, it is provided at the outlet of the condenser to detect the temperature of a portion where changes in refrigerating capacity due to the outside temperature can be detected, and the reference voltage v3 is corrected with respect to the outside temperature so that a constant amount of ice is produced using the detected temperature.

FIG. 5 is a graph for explaining the correction characteristics of the reference voltage Vs by the thermistor TH1, in which the horizontal axis represents the temperature T of the condenser detected by the thermistor TH, and the vertical axis represents the impedance Z. It represents.

When the impedance between the contact and ground in the condenser temperature detector varies with temperature T as shown by line e in Figure 5, the detector produces constant ice regardless of the outside temperature. It is assumed that a reference voltage Vs of .

The characteristics of line e are determined through experiments for each type of ice maker, and once line e is determined, the circuit configuration of the condenser temperature detector shown in Figure 4 can be designed as appropriate. be.

That is, in FIG. 4, the impedance between the contact and the ground is reduced by connecting the correction resistor R6 shown by line Rc' (see FIG. 5) in parallel to the thermistor TH1 shown by line T H1' in FIG. By approximating the line e, it is possible to produce a constant amount of ice throughout the seasons, regardless of the outside temperature, that is, the condenser temperature T.

In the description of the circuit configuration in FIG. 4, the reference voltage ■s is corrected, but it is also possible to correct the detected voltage ■7 in accordance with the outside temperature.

By using the method shown in Figures 4 and 5 to complete the ice-making operation, it is possible to operate the ice-making machine stably with respect to the outside temperature, but what is more noteworthy is that This type of ice-making completion control makes it possible to save water from melting ice.

In other words, in the past, the operation of ice-making completion control was unstable, and when ice grew excessively, it was necessary to flow extra ice-melting water to melt several ice cubes. In ice-making control devices, the amount of ice-melting water sprinkled had to be set in consideration of the worst-case conditions, but with this invention, it is possible to fully automate the process of always making the appropriate amount of ice, thus eliminating the need for excessive In order to avoid the worry of water leakage, it is possible to configure the second operational amplifier 32 shown in FIG. It was made.

The operation of one embodiment of the fully automatic ice-making control device according to the present invention has been described above for a fountain-type ice maker equipped with a water-cooled condenser, but it can also be applied to an ice maker equipped with an air-cooled type.
It is also applicable to various types of ice makers other than the fountain type.

In the case of an air-cooled type, first, the condensed water outlet temperature detector 13,
The related fourth operational amplifier 50, abnormal condensed water indicator 22, fifth operational amplifier 51, fourth relay X4, etc. are no longer necessary, and the circulating pump shown in FIG. The temperature sensing element (thermistor TH1) in the condenser temperature detector 10 may be connected in parallel with the motor PM and further installed to measure the air cooling temperature.

As described above, according to the present invention, a cooler temperature detector including a single temperature sensing element such as a thermistor is used to detect the temperature of the cooler, and on the other hand, the temperature of the portion where the refrigerating capacity can be detected based on the outside temperature is detected. A thermistor for correcting the outside temperature is attached to the structure so that ice making completion control and ice removal completion control can be performed all at once from these two temperature detection signals, making it possible to obtain homogeneous ice cubes with a constant volume and reducing manufacturing costs. It is also possible to reduce the

In addition, when controlling the completion of ice removal, since the detection element is composed of a thermistor as described above, it is particularly difficult to
It is possible to prevent unstable detection operation or failure to detect at temperatures (°C).

Furthermore, by stably operating the ice-making completion control to obtain a homogeneous and constant volume of ice blocks, the amount of ice-melting water sprinkled to melt several ice cubes can be kept to the minimum necessary, and the temperature of the cooler can be detected. Since the ice melting water sprinkling start control can be carried out based on the detection signal after the container has taken off and fallen from the water, a good water saving effect is achieved, and this is remarkable when combined with the stable operation of the ice removal completion control.

Additionally, since a thermistor is used as the cooler temperature detector instead of a gas-filled thermostat, it has the advantage of being unaffected by outside temperature and free from restrictions on installation location.

In addition, by installing a counter to measure the elapsed time of ice-making operation, it is possible to prevent the refrigeration capacity from decreasing due to an abnormality in the refrigeration circuit, and it may take a long time to reach the ice-making completion temperature, or it may become impossible to reach it, and the specified maximum time may be exceeded. If it exceeds the limit, the ice-making operation is forcibly terminated and an abnormality display is displayed to notify the user, thereby making it possible to prevent damage to the ice-making machine.

In addition, while a mechanically configured water storage switch is built into the interior of the water storage, this water storage switch cuts off power to the ice-making mechanism drive circuit only during ice-removal operation. There is no risk of ice making surplus residual water remaining and causing unexpected situations such as freezing and bursting, further improving safety, and in summer, ice making operation can be started using the residual water that has been left for a long time after water storage is finished. However, it is unsanitary and there is no fear that the water system will be contaminated with water stains and the like.

In addition, an automatic reset circuit has been added to output a signal for a certain period of time to force ice removal operation when the power is turned on, which not only eliminates the need for manual operations during installation, but also Even if a power outage occurs during ice-making operation, or if the power is turned off and then on again due to the user's convenience, there is a risk of destruction or damage to parts around the mechanism caused by extreme overgrowth of ice due to continued ice-making operation. There is no such thing as breaking the ice.

In addition, we installed a condensed water temperature detector in the water-cooled condenser, and when a defect in the automatic water supply valve is detected, an abnormality display alarm is issued to notify the user, so it can be detected immediately and waste is eliminated. It doesn't consume a lot of water either.

In addition, since the freezing temperature of condensed water during winter storage is detected by the signal from the condensed water temperature detector and the freezing temperature of the condensed water is energized to the antifreeze heater, there is no risk of the water-cooled condenser freezing and bursting, making it impossible to repair. lost.

The ice-making control device according to the present invention overcomes all of the above-mentioned drawbacks of this type of ice-making machine, and also enables automatic ice-making control, which was previously possible for the first time by using a microcomputer or the like. Complete automation has been achieved by configuring all the necessary functions for the system in a simple and inexpensive manner and integrating them into one control circuit.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a refrigeration circuit of an ice maker to which the present invention is applied, FIG. 2 is a diagram showing an ice making mechanism drive circuit for energizing the refrigeration circuit shown in FIG. 1, and FIG. FIGS. 4 and 5 are a circuit diagram and a graph diagram, respectively, for explaining the ice-making completion control according to the present invention. In the figure, 1 is an ice storage box, 2 is a water tray, 3 is an ice-making water tank, 4 is a selector switch, 5 is a cooler, 5c is a cooler temperature detector, 6 is a circulation pump, 8 is a condenser, and 10 is a condenser 12 is an automatic water supply valve, 13 is a condensed water outlet temperature detector, 14 is a mechanical water storage switch, AM is a water pan drive motor, PM is a circulation pump motor, CM is a compressor, H is an antifreeze heater , W■ is an electromagnetic water supply valve, HGV is a hot gas valve,
20 is a control circuit, 31 is a first operational amplifier, and 32 is a second operational amplifier.
, 33 is a third operational amplifier, 34 is a delay circuit, 39 is a counter, 43 is an automatic reset circuit, 42 is an OR circuit, 44 is a NOR circuit, FF1 and FF2 are flip-flops, (42, 44, FF1 and FF2 constitute a holding circuit. ), 50 is a fourth operational amplifier, 51 is a fifth operational amplifier, Xl is a first relay (water storage detection relay -), and X2 is a second operational amplifier.
Relay (relay for operation command), X3 is the third relay (relay for water supply valve), X4 is the fourth relay (relay for heater),
THl and TH2 are thermistors, and RO is a correction resistor.

Claims (1)

[Scope of Claims] 1. A refrigeration circuit including a water tray, a condenser, and a cooler, a water storage provided below the cooler for storing ice generated by the cooler, and the refrigeration circuit. an ice-making mechanism drive circuit including a compressor, a circulation pump motor, a water tray drive motor, a water supply valve, and a hot gas valve to energize the ice-making mechanism drive circuit; In an ice maker configured to control ice making operation and ice removing operation of a refrigeration circuit, the control circuit detects the temperature of a portion where a change in refrigeration capacity due to outside temperature can be detected and outputs a reference signal representing a temperature at which ice making is completed. a first operational amplifier that inputs both signals from a first temperature detector and a second temperature detector that detects the temperature of the cooler and outputs an ice making completion control signal by comparing these two signals; ,
a second operational amplifier that inputs a signal from the second temperature detector and a reference signal representing an ice melting water sprinkling start temperature and outputs an ice melting water sprinkling start control signal; and a signal from the second temperature detector. and a third operational amplifier that inputs a reference signal representing an ice-off completion temperature and outputs an ice-off completion control signal, and a holding circuit connected to the outputs of the first and third operational amplifiers. , outputs a first holding signal when the ice making completion control signal from the first operational amplifier is input;
When the ice removal completion control signal from the third operational amplifier is input, canceling the output of the first holding signal,
Next, until the ice making completion control signal is input, a second holding signal is output, and the holding circuit is connected to the output of the holding circuit, and the ice removing operation is performed while the first holding signal is inputted. an operation command relay that provides a contact signal to the ice-making mechanism 1 drive circuit, and a contact signal to the ice-making mechanism 1 drive circuit to perform the ice-making operation while the second holding signal is being input;
and a water supply valve relay that is connected to the output of the operational amplifier and outputs a contact signal for opening the water supply valve when the ice melting water sprinkling start control signal from the second operational amplifier is input. A fully automatic ice-making control device featuring: 2 A mechanical water storage switch that detects a predetermined amount of water stored in the water storage and outputs a water storage completion signal and a changeover switch that detects the raised and lowered positions of the water tray are connected to the control circuit, and the mechanical A contact signal that cuts off the power to the ice making mechanism drive circuit when the signal from the water storage switch through the delay circuit indicates a predetermined water storage amount and the signal from the changeover switch indicates the lowered position of the water tray. A completely automatic ice-making control device according to claim 1, which is provided with a water accumulation detection relay that outputs an output. 3. The control circuit includes an automatic reset circuit that outputs a reset signal for a certain period of time when the power is turned on, and the reset signal is applied to the holding circuit as the ice-making completion control signal, or The fully automatic ice-making control device according to item 2. 4. The control circuit includes an oscillator for time measurement and a counter that counts clock pulses from the oscillator, and when the water tray is in the lowered position, the counter performs its counting operation in response to a signal from the changeover switch. and when the water tray is in the raised position, the ice making operation time of the ice maker is measured, and when the ice making operation time exceeds a specified maximum time, the holding circuit is configured to give the ice making completion control signal. A completely automatic ice-making control device according to any one of claims 1 to 3. 5 In the case where the ice maker has an air-cooled condenser, the first temperature detector is a combination of a thermistor and a correction resistor that detects the condenser outlet temperature as the temperature of a portion where changes in refrigerating capacity due to outside temperature can be detected. The fully automatic ice making control according to any one of claims 1 to 4, wherein the second temperature detector is a combination of a thermistor and a correction resistor for detecting the temperature of the cooler. Device. 6 When the ice maker has a water-cooled condenser, the control circuit inputs a signal from a condensed water temperature detector that detects the temperature of the condensed water outlet and a reference signal representing an abnormal temperature of the condensed water. claim 1, further comprising a fourth operational amplifier for comparing these two signals, the fourth operational amplifier outputting a signal for displaying an alarm when abnormal temperature of the condensed water is detected. 4. The fully automatic ice-making control device according to any one of items 4 to 4. 7. The control circuit includes a fifth operational amplifier that inputs a signal from the condensed water temperature detector and a reference signal representing the freezing temperature of the condensed water and compares these two signals; When the freezing temperature of the water is detected, this fifth
Claim 6: A heater relay energized by an output from an operational amplifier, which outputs a contact signal for energizing a heater to prevent condensed water from freezing. Fully automatic ice-making control device as described in section.