JPH06257914A - Water supply abnormality detection circuit of automatic ice machine - Google Patents

Abstract

(57) [Summary] [Purpose] Not only when the ice tray is not supplied with water at all, or when the ice tray is supplied with almost no water, the amount of water that is to be supplied to the ice tray is lower than the appropriate value. By making it possible to detect abnormalities when the number is small or excessive, the reliability of the automatic ice making machine is further improved. [Structure] The automatic ice machine water supply abnormality detection circuit
A temperature sensor 9 for detecting the temperature inside, and a first for outputting an "H" signal when the temperature inside the ice tray 2 is -10 ° C or lower.
Voltage comparator circuit 13 and a second voltage comparator circuit 14 which outputs an "H" signal when the temperature is -1 ° C or lower,
A third voltage comparison circuit 15 which outputs an “H” signal when the temperature is + 1 ° C. or lower;
And a logic circuit 16 which outputs an "H" signal when the temperature is in ° C.

Description

Detailed Description of the Invention

[0001]

The present invention relates to continuous water supply, ice making,
The present invention relates to an automatic ice maker that repeats ice removal, and particularly to a water supply abnormality detection circuit for an automatic ice maker that detects an abnormality in the amount of water supplied to an ice tray.

[0002]

2. Description of the Related Art An automatic ice maker that automatically repeats water supply, ice making, and ice removal continuously is used in commercial refrigerators, household refrigerators, and the like.
An automatic ice making machine described in Japanese Patent No. 61 can be mentioned.

In the automatic ice making machine according to the above-mentioned known example, a water supply controller for supplying water into a horizontally supported ice making tray and a temperature sensor such as a thermistor or a thermal reed switch are integrally provided in the ice making tray. A freezing detection unit that detects freezing of water supplied to the ice tray, a motor drive unit that rotationally drives the ice tray to discharge ice pieces in the ice tray, and a predetermined time after operating the water supply control unit. A water supply detection unit that outputs a water supply abnormality signal when the temperature detected by the temperature sensor is lower than a predetermined temperature even after a lapse of time is provided.

Therefore, the above-mentioned known automatic ice making machine is
For example, when the water tank that stores the water to be supplied to the ice tray becomes dry, or when water supply to the ice tray is no longer possible due to a malfunction of the water supply system, the water supply detection unit should detect it. Since it is possible to prevent insufficient ice making, the reliability of the ice making machine can be improved in this respect.

[0005]

However, the water supply detector having the above structure can detect an abnormality in the water supply when no water is supplied to the ice tray or when almost no water is supplied to the ice tray. However, if the amount of water to be supplied to the ice tray is less than the appropriate value or is excessive, it is difficult to say that it cannot detect abnormalities and still has sufficient reliability for practical use. .

The present invention has been made in order to solve the deficiency of the above-mentioned prior art, and not only when the ice tray is not supplied with water at all, or when the ice tray is hardly supplied with water, the ice tray is not An object of the present invention is to provide a more reliable automatic ice maker by making it possible to detect a water supply abnormality even when the amount of water to be supplied is less than an appropriate value or is excessive.

[0007]

In order to achieve the above-mentioned object, the present invention provides a water supply control unit for supplying water to an horizontally-supported ice making tray, and a temperature in the ice making tray. A temperature sensor for detecting the temperature, a melting point detector for detecting that the temperature detected by the temperature sensor is near the melting point of water, and a temperature detected by the temperature sensor being lower than a predetermined temperature lower than the melting point of water A freezing detection unit, and a motor drive unit that rotates the ice tray in reverse to discharge the ice pieces inside, and after this discharge, rotates the ice tray in the opposite direction to restore the horizontal state.
After the water supply controller is operated to supply a predetermined amount of water into the ice tray, it is detected that the states of the melting point detector and the freezing detector continue to be constant, and the state is continued. A water supply abnormality detection circuit provided with a water supply detection unit that detects the amount of water contained in the ice tray according to time and outputs a water supply abnormality signal when the amount of water is abnormal.

[0008]

As described above, when the ice maker has an abnormal water supply, when the ice tray is not supplied with water at all or when the ice tray is hardly supplied with water, the amount of water to be supplied to the ice tray is an appropriate value. If it is less than the above, the amount of water to be supplied to the ice tray may be excessive than the appropriate value. In the above case, the freezing detection unit continues to detect that the temperature of the ice tray is lower than the melting point of water, so that the water supply detection unit can detect an abnormality. Further, in the above case, the melting point detecting unit detects that the state of the temperature of the ice tray near the melting point of water is shorter than the standard state, so the water supply detecting unit can detect an abnormality. In the above case, the melting point detection unit detects that the temperature of the ice tray near the melting point of water has been longer than the standard state, so the water supply detection unit can also detect an abnormality.

As described above, according to the above-mentioned means, it is possible to detect an abnormality in all kinds of water supply abnormality, so that the reliability of the automatic ice making machine can be further improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the automatic ice making machine according to this embodiment includes a microprocessor 1 as a control unit, an ice tray 2 for making ice, and a water supply pump 3 for supplying water to the ice tray 2.
And a water supply tank 4 for storing water to be supplied by the water supply pump 3.
A first motor 5 for driving the water supply pump 3; a first motor driver 6 for supplying electric power to the first motor 5;
A second motor 7 for rotating the ice tray to discharge ice pieces in the ice tray 2, and a second motor 7 for supplying electric power to the second motor 7.
Motor driver 8, a temperature sensor 9 for detecting the temperature in the ice tray 2, a first reference voltage generating circuit 10 for generating an output voltage of the temperature sensor 9 corresponding to -10 ° C, and -1 ° C.
Second reference voltage generating circuit 11 for generating the output voltage of the temperature sensor 9 corresponding to the temperature sensor 9 and the temperature sensor 9 corresponding to + 1 ° C.
A third reference voltage generating circuit 12 for generating the output voltage of
The voltage output from each of these three reference voltage generation circuits 10, 11 and 12 is compared with the output voltage of the temperature sensor 9, and when the voltage output from the temperature sensor 9 is lower, the voltage is higher. First, second, and third voltage comparison circuits 13, 14, 15 that output a level signal "H"
And a logic circuit 16 which inverts the output of the second voltage comparison circuit 14 and obtains a logical product of the output value and the output value of the third voltage comparison circuit 15.

In FIG. 2, the vertical axis represents the temperature of the ice tray 2 and the horizontal axis represents the freezing time from the start of water supply, and the temperature of the water supply from the water supply pump 3 is constant and the water supply volume of the ice tray 2 changes. It shows a temperature change state. As is clear from FIG.
When the water supply temperature from the water supply pump 3 is constant and the water supply amount is large, as shown in the curve 17, the maximum reached temperature T1 is the maximum reached temperature T when the water supply amount indicated by the curve 18 is standard.
The time AA, which is higher than 2 and the ice tray temperature remains 0 ° C., is longer than the 0 ° C. maintenance time BB when the amount of water supply indicated by the curve 18 is standard. On the other hand, when the water supply temperature from the water supply pump 3 is constant and the water supply amount is small, the maximum attainable temperature T3 is the maximum attainable temperature when the water supply amount displayed by the curve 18 is standard, as shown in the curve 19. T
The time CC that is lower than 2 and the temperature of the ice tray remains 0 ° C. is shorter than the 0 ° C. maintenance time BB in the case where the water supply amount indicated by the curve 18 is standard.

In FIG. 3, the vertical axis represents the temperature of the ice tray 2 and the horizontal axis represents the freezing time from the start of water supply. The water supply pump 3 supplies a constant amount of water and the water supply temperature of the ice tray 2 changes. It shows a temperature change state. As is clear from FIG.
When the amount of water supplied from the water supply pump 3 is constant and the water supply temperature is high, as shown in the curve 20, the maximum reached temperature T4 is the maximum reached temperature T when the water supply temperature displayed by the curve 21 is standard.
Although it is higher than 5, the time DD during which the temperature of the ice tray remains 0 ° C. is almost the same as the 0 ° C. maintenance time EE when the feed water temperature shown in the curve 21 is standard. On the contrary, when the amount of water supplied from the water supply pump 3 is constant and the water supply temperature is low,
As shown in the curve 22, the highest temperature T6 is
Although the feed water temperature indicated by is lower than the maximum reached temperature T5 in the standard case, the time FF in which the temperature of the ice tray remains 0 ° C. is 0 when the feed water temperature displayed in the curve 21 is standard.
It becomes almost the same as the temperature maintenance time EE.

It can be seen from FIGS. 2 and 3 that even if the temperature of the water supply from the water supply pump 3 changes, the amount of water supply can be detected by detecting the time during which the temperature of the ice tray remains 0 ° C. Further, when the ice tray 2 is in a drought state, the temperature of the ice tray 2 becomes constant at T7.

FIG. 4 shows an example of a control flow of the ice making operation by the microprocessor 1 provided in the above-mentioned automatic ice making machine.

The microprocessor 1 drives the water supply motor 5 via the motor driver 6 to supply the water in the water storage tank 4 to the ice tray 2 by the water supply pump 3 (S-
1). Next, the first provided in the microprocessor 1
The counting timer (not shown) of (1) is cleared to zero to start counting (S-2), and the time when the freezing output which is the comparison output of the voltage comparison circuit 13 is "H" is measured (S-3).

When the icing output is "H" continuously for 1 minute or more (S-4), it is determined that the inside of the ice tray is in a drought state, and the drought error is dealt with, for example, the warning light is turned on. Etc. are performed (S-5). If the icing output reverses to "L" before 1 minute has elapsed, it indicates that the temperature of the ice tray 2 is in the range of -1 ° C to + 1 ° C. In this case, it waits until the melting point output which is the output signal of the logic circuit 16 becomes "H" (S-6), and when the melting point output is inverted to "H", the second signal provided in the microprocessor 1 is provided. The counting timer (not shown) of is cleared to zero and counting is started (S-
7) The time until the melting point output becomes "L" is measured (S-8). If the water temperature and amount of water supplied to the ice tray 2 are standard, it is assumed that it takes 50 to 70 minutes for the melting point output to reverse to "L".
When it is determined in step S-9 that the time is 50 minutes or less, it is determined in step S-10 whether the freezing output is "H", and the freezing output is "H". If it is, an error of insufficient water supply is processed (S-11). When it is determined in step S-10 that the freezing output is "L", the melting point output is "H" in step S-12.
If the melting point output is "H", the process returns to step S-10. When it is determined in step S-12 that the melting point output is "H", the process returns to step S-7 and the subsequent operations are repeated. As can be seen from FIGS. 2 and 3, depending on the amount of water or the water temperature of the water supplied into the ice tray 2, the melting point may be the passage point and the temperature of the ice tray 2 may or may not increase thereafter. S-10 to S-
If you do 12 actions, you can accurately understand each water supply condition,
It is possible to reliably determine an underwater supply error. If it is determined in step S-9 that the melting point output has inverted to "L" for 50 minutes or more, step S-
At 13, it is determined whether the time is 70 minutes or less. If it is determined that the time taken for the melting point output to reverse to "L" is 70 minutes or more, step S
At -14, the error of excess water supply is processed. If it is determined in step S-13 that the time until the melting point output is inverted to "L" is 70 minutes or less, it is determined that the ice making is completed in a normal state, and therefore the microprocessor 1 Drives the ice tray rotation motor 7 via the motor driver 8 to rotate the ice tray 2 so that the ice tray 2
Remove and release the ice pieces inside.

[0017]

As described above, according to the present invention,
Abnormalities not only when the ice tray is not supplied with water at all or when the ice tray is supplied with almost no water, but also when water is supplied but the amount of water to be supplied to the ice tray is less than the appropriate value or excessive. Since it is possible to detect even, the reliability of the automatic ice maker can be further improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an automatic ice making machine according to an embodiment.

FIG. 2 is a graph showing a temperature change of an ice tray when water having a constant water supply temperature and different water supply amounts is supplied.

FIG. 3 is a graph showing a temperature change of an ice tray when water having a constant water supply amount and different water supply temperatures is supplied.

FIG. 4 is a control flow of the microprocessor during the ice making operation.
It is a figure.

[Explanation of symbols]

 1 Microprocessor 2 Ice tray 3 Water supply pump 4 Water storage tank 9 Temperature sensor 10, 11, 12 Reference voltage generation circuit 13, 14, 15 Voltage comparison circuit, 16 Logic circuit, 17 Temperature change of ice tray when the amount of water supply is large 18 Temperature change of ice tray when water supply is standard 19 Temperature change of ice tray when water supply is low 20 Temperature change of ice tray when water supply temperature is high 21 Temperature change of ice tray when water supply temperature is standard 22 Temperature change of ice tray when the water supply temperature is low

Claims (1)

[Claims] 1. A water supply control unit for supplying water into a horizontally supported ice tray, a temperature sensor for detecting a temperature in the ice tray, and a temperature detected by the temperature sensor is near a melting point of water. Melting point detection section, an ice detection section that detects that the temperature detected by the temperature sensor is lower than a predetermined temperature lower than the melting point of water, and the ice tray is rotated in reverse to discharge internal ice pieces. Then, after this discharging, the ice tray is rotated in the opposite direction to return to a horizontal state, and the water supply controller is operated to supply a predetermined amount of water into the ice tray, and then the melting point. Detects that the conditions of the detection unit and the ice detection unit continue to be in a constant state, and detects the amount of water contained in the ice tray based on the duration of the state, and supplies water if the amount of water is abnormal. And a water supply detector that outputs an abnormal signal. A water supply abnormality detection circuit for an automatic ice machine.