JP2001082867A - Refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To greatly decrease operating force required for opening a door and prevent the temperature of a motor-operated door opening unit from rising to abnormal temperature by opening the door by the motor-operated door opening unit against the attracting force of a magnet gasket. SOLUTION: A refrigerator main body is provided with a motor-operated door opening unit having a solenoid as a driving source. The motor-operated door opening unit exerts opening force on a door to open the door when it is energized. When the door is continuously opened and closed (the motor- operated door opening unit is controlled to be energized), the temperature of the motor-operated door opening unit abruptly rises. When the temperature of the motor-operated door opening unit rises to a previously set temperature (100 deg.C), a control circuit inhibits the operation of the motor-operated door opening unit and controls the motor-operated door opening unit not to operate agasin until the temperature of the motor-operated door opening unit is lowered to a preset allowable temperature (90 deg.C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator having a door which is closed by a magnet gasket.

[0002]

In recent years, refrigerators have been remarkably increased in size, and accordingly, doors for opening and closing refrigerators and the like have also been increased in size. In such a refrigerator door, it is normal that the closed state is held by the attraction force of the magnet gasket. However, when the door is enlarged, the total extension of the magnet gasket becomes longer. As a result, the operating force required to open the door tends to increase. If the operating force required to open the refrigerator door becomes large in this way, it imposes a heavy burden on a weak person (woman, child or old man), so it is desirable to take some measures.

As one of such measures, there is an electric assist system in which a door opening device for opening a door using an actuator such as an electromagnetic solenoid is considered. However, in implementing such a door opening device, there are, for example, the following problems to be solved. That is, the frequency of opening and closing the refrigerator door is usually 40 to
About 50 times a day, and the opening and closing interval is relatively long,
In children's pranks, in-store exhibits, etc., the doors may be opened and closed intensively. In this case, the temperature rise due to one energization of the electromagnetic solenoid is slight, and there is no problem if there is a certain heat radiation period. If this occurs, a drastic temperature rise may be caused, and the temperature may rise to an abnormal temperature.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to enable an electric door opening unit to open a door against the attraction force of a magnet gasket. It is an object of the present invention to provide a refrigerator capable of greatly reducing an operation force required for opening and preventing a situation in which an electric door unit rises to an abnormal temperature.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is directed to a refrigerator having a door which is held closed by a magnet gasket. An electric door unit for opening the door against the attraction force of the magnet gasket by applying a force in the opening direction to the door, and control means for controlling the operation of the electric door unit; Is characterized in that when the temperature of the electric door opening unit rises to a preset value, control for restricting the operation of the electric door opening unit is performed.

According to this structure, when the control unit controls the power supply of the electric door unit, the electric door unit applies a force in the opening direction to the door held in the closed state by the magnet gasket. As a result, the door is opened against the attraction of the magnet gasket. In this case, when the opening and closing of the door (control of energization of the electric door opening unit) is performed continuously, the temperature of the electric door opening unit increases sharply, but the temperature of the electric door opening unit is reduced to a preset temperature. Ascending,
The control means limits the operation of the electric door opening unit. Therefore, it is possible to prevent the electric door unit from rising to an abnormal temperature.

In this case, as in the invention described in claim 2,
The control means inhibits the operation of the electric door unit when the temperature of the electric door unit rises to the set value, and controls the electric door unit until the temperature of the electric door unit falls to a preset permission temperature. Can be controlled so as not to operate again. According to this configuration, when the temperature of the electric door opening unit rises to the set value, the operation of the electric door opening unit is completely prohibited, so that the electric door opening unit rises to an abnormal temperature beforehand. Can be prevented.

According to a third aspect of the present invention, when the temperature of the electric door unit rises to a set value, the control means prohibits the operation of the electric door unit and the permission period. A configuration in which a permission / prohibition cycle that repeats a prohibition period may be performed may be adopted. For example, in the case of a store display, if the operation of the electric door opening unit is prohibited for a long time, it may be inconvenient. In this regard, according to the configuration described above, when the temperature of the electric door opening unit rises to the set value, the electric door opening unit cannot be operated during the prohibition period, but when the permission period comes, the electric door opening unit is not operated. Can work. Therefore, the electric door opening unit can be operated without waiting for a long time. In this case, the operable period of the electric door-opening unit is limited, so that the temperature rise of the electric door-opening unit can be suppressed as much as possible.

According to the present invention, the temperature of the electric door opening unit can be estimated and obtained by the control means on the basis of a preset degree of temperature rise and a degree of temperature decrease. In such a case, there is no need to provide a circuit for detecting the temperature of the electric door unit.

According to a fifth aspect of the present invention, the electric door unit includes an electromagnetic solenoid as a driving source, and the temperature of the electric door unit is determined by measuring a resistance value of a coil of the electromagnetic solenoid. Can be determined based on the In such a case, a temperature close to the actual temperature of the coil in the electromagnetic solenoid can be detected, and more accurate control can be performed.

According to a sixth aspect of the present invention, the control means has a storefront display mode. In the storefront display mode, a permission period for permitting the operation of the electric door opening unit and a permission period for prohibiting the operation are prohibited. / A prohibition cycle can be always executed. In this case, in the storefront display mode, the permission / prohibition cycle is executed irrespective of the temperature of the electric door opening unit, so that the control of the control means is simplified.

[0012]

1 to 9 show a first embodiment of the present invention.
An example is shown and will be described below. 3 and 4 show a front view of the refrigerator according to the present embodiment and a schematic perspective view with the refrigerator door open. 3 and 4, in a refrigerator body 1 configured as a heat insulating box having a well-known structure, a refrigerator compartment 2, a vegetable compartment 3, an ice making compartment 4, a switching compartment 5 capable of switching the internal temperature to a plurality of stages, The freezer compartment 6 is provided in order from the top (however,
The ice making room 4 and the switching room 5 are arranged side by side on the left and right). The switching chamber 5 has a well-known configuration in which the switching chamber 5 is used in various modes such as a freezing room, a chilled room, a refrigerator room, a vegetable room, and the like according to the switching of the internal temperature.

A hinge-opening door 2a is provided on the front surface of the refrigerator compartment 2, and a storage container (not shown) is provided on each front surface of the vegetable compartment 3, the ice making compartment 4, the switching compartment 5, and the freezing compartment 6. )
Drawer-type doors 3a, 4a, 5a and 6a are provided. A magnet gasket 2b is attached to a peripheral portion on the back side of the door 2a for the refrigerator compartment 2,
The door 2a is configured to be held closed by the magnet gasket 2b being attracted to the refrigerator body 1 side. Although not shown, other doors 3a, 4a,
Magnet gaskets are also attached to the peripheral edges on the back side of 5a and 6a.

An electric door unit 7 for applying a force in the opening direction to the door 2a for the refrigerator 2 is attached to the ceiling of the refrigerator body 1. As shown in FIG. 5, which shows a cross-sectional structure of the upper part of the refrigerator, the electric door unit 7 is installed in a semi-embedded state in a recess 1a formed in the ceiling of the refrigerator body 1, and is made of synthetic resin. An electromagnetic solenoid 9 which is DC-driven as a driving source is housed in a case 8 made of a metal. In this case, the case 8 is composed of a rectangular container-shaped base 8a fitted into the recess 1a and a cover 8b mounted on the base 8a so as to cover the base 8a from above.
b protrudes upward from the ceiling of the refrigerator body 1.
The base 8 a is fixed to the ceiling of the refrigerator body 1 by screws 10 at a plurality of locations.

As shown in FIG. 6, the electromagnetic solenoid 9 includes a coil unit 11 in which a coil 11a formed in a cylindrical shape is resin-molded, a yoke 12 provided in the coil unit 11, and a coil unit 11 inside the coil unit 11. The main components are a plunger 13 made of a magnetic material, which is provided so as to be able to move in the axial direction while penetrating the plunger, and a push rod 14 made of a nonmagnetic metal fixed coaxially to the plunger 13. The plunger 13 and the push rod 14 move in the direction of the door 2a in the energized state (state in which the coil 11a of the coil unit 11 is energized) (FIG.
And in the direction of arrow A in FIG. 6). In this case, a flange 13a made of, for example, a C-ring is provided at one end (an end in the direction opposite to the arrow A) of the plunger 13 to prevent the plunger 13 from coming off in the direction of the arrow A. A return spring 15 composed of a compression coil spring is provided around the periphery so as to apply an extension force between the flange 13a and the coil unit 11. The coil unit 11 is provided with a thermal fuse 16 for protection.

At the upper edge of the door 2a for the refrigerator compartment 2, there is integrally provided a receiving member 17 with which the tip of the push rod 14 abuts, and when the electromagnetic solenoid 9 is energized, the plunger 13 and When the push rod 14 is urged in the direction of arrow A, the receiving member 17 is pressed by the push rod 14, and the door 2a is opened in response to the force of the magnet gasket 2b. I have. In this case, a rubber cap 14a is attached to the tip of the push rod 14 as a cushioning member, and the receiving member 17 is also provided with a rubber cap as a cushioning member at the portion pressed by the tip of the push rod 14. Plate 17a is attached. Further, a flange 13 a of the plunger 13 is provided in the case 8 of the electric door unit 7.
An auxiliary spring 18 composed of a torsion coil spring is provided so as to urge the end surface on the side against the return spring 15 in the direction of arrow A, and in a steady state in which the door 2a is closed, The distal end of the rod 14 comes into contact with the receiving member 17 by the urging force of the auxiliary spring 18. The urging force of the auxiliary spring 18 is
As a matter of course, it is set to a level smaller than the attraction force of the magnet gasket 2b.

As shown in FIG. 3, a display panel 19 and a handle 20 are provided on the front surface of the door 2a for the refrigerator compartment 2 in a vertically arranged state. In this case, although not specifically shown, the display panel 19 includes the refrigerator compartment 2 and the freezer compartment 6.
A display for displaying the temperature in the chamber, the switching mode of the switching chamber 5, and the like;
An operation switch group for individually switching the set temperatures of the refrigerating compartment 2, the switching compartment 5, and the freezing compartment 6 is provided. In addition, the handle 20 is provided with a space on its back surface into which a user's finger enters, and is a normally-open type door opening switch that is turned on when the handle 20 is pulled and pressed. 7 (indicated by reference numeral 21 in FIG. 7). In addition, this opening switch 21
Can be constituted by a mechanical switch such as a microswitch, but can also be constituted by an optical switch or a magnetic switch using a photo interrupter.

On the other hand, FIG. 7 shows a circuit configuration related to the electric door unit 7 in the electric configuration of the refrigerator according to the present embodiment, which will be described below.
In FIG. 7, the electromagnetic solenoid 9 of the electric door unit 7 is configured to be DC-driven by the output of the DC power supply circuit 22 via the thermal fuse 16. In this case, the DC power supply circuit 22 is composed of a full-wave rectifier circuit 23 and a smoothing capacitor 24 receiving the rectified output thereof.
5 is connected. In the full-wave rectifier circuit 23, one AC input terminal is connected to the commercial AC power supply 2 via a protection resistor 26 for suppressing inrush current and a normally open relay switch 27.
8 and the other AC input terminal is connected via a current fuse 29 to the other terminal of the commercial AC power supply 28. The thermal fuse 16 is configured to be blown when the temperature of the electromagnetic solenoid 9 rises to, for example, 130 ° C.

The relay switch 27 is turned on for a predetermined period of time, for example, 0.5 seconds by a control circuit 30 constituting a control means via a timer circuit 31. An operation signal (ON signal) of the door opening switch 21 is input to the control circuit 30.
The control circuit 30 includes a microcomputer, and controls the relay switch 27 via a timer circuit 31 based on the input of the operation signal of the door opening switch 21, thereby controlling the electric door unit 8. The electromagnetic solenoid 9 is controlled.

Next, the operation of this embodiment will be described.

Now, when the door 2a of the refrigerator compartment 2 is closed, as shown in FIG. 5, the magnet gasket 2b is attracted to the front surface of the refrigerator body 1, so that the closed state is maintained. I have. In this closed state, the electromagnetic solenoid 9 of the electric opening / closing unit 7 is turned off, and the cap 14a at the tip of the push rod 14 is in contact with the backing plate 17a of the receiving member 17 on the door 2a side.

From the closed state of the door 2a, the door 2a
When the handle 20 is pulled or pressed to open the door and the door opening switch 21 is turned on, the control circuit 30 sends the relay switch 2 via the timer circuit 31.
7 is turned on for a predetermined time, in this case, about 0.5 second.
Thus, the electromagnetic solenoid 9 of the electric opening / closing unit 7 is energized and driven only for about 0.5 seconds. Then
The plunger 13 and the push rod 14 of the electromagnetic solenoid 9 are driven by an arrow A against the spring force of the return spring 15.
In this case, the receiving member 17 provided on the door 2a is pressed by the push rod 14 so that the magnet gasket 2b is peeled off from the refrigerator body 1, and the door 2a is opened accordingly. Become so.

When the door 2a is opened as described above,
The push rod 14 is largely projected forward, but when the electromagnetic solenoid 9 is subsequently turned off, the plunger 13 and the push rod 14 are instantaneously moved back to the original position by the spring force of the return spring 15. Will be returned. When closing the door 2a, the door 2a is turned in the closing direction as in the normal case. When the door 2a is in the closed state, the magnet gasket 2b is attracted to the front surface of the refrigerator body 1, and the receiving member 17 on the door 2a presses the distal end of the push rod 14, so that the push rod 14 and the plunger 13 Is returned to the original position.

Here, the electromagnetic solenoid 9 is DC-driven by the DC power supply circuit 22 as described above. When AC 100 V of the commercial AC power supply 28 is applied to the DC power supply circuit 22, DC 141 V is not applied to the electromagnetic solenoid 9 because there is a voltage drop in each part.
About 120 V will be applied. In this case, a current of about 2 A flows through the electromagnetic solenoid 9 and about 240
W will enter. One operation time of the electromagnetic solenoid 9 is about 0.5 seconds. Therefore, when the electromagnetic solenoid 9 is operated once, the temperature of the electromagnetic solenoid 9 rises by about 0.4 k (degree). In one operation, the temperature rise is small, but when operated continuously, the temperature rises considerably.

FIG. 8 shows that when the room temperature is 30 degrees,
It shows the degree of temperature rise when the electromagnetic solenoid is operated. FIG. 8 shows a case where the electromagnetic solenoid is continuously energized (power is kept energized) and a case where the door 2a is opened and closed in the shortest time. The energization is repeated, the energization of the electromagnetic solenoid is repeated once every 0.5 seconds (0.5 seconds), and the energization is repeated once every 10 seconds. The case where the energization of the electromagnetic solenoid is repeated twice (0.5 seconds) and the case where the energization of the electromagnetic solenoid is repeated once (0.5 seconds) every 20 seconds, which is twice as long, are shown. ing.

As can be seen from FIG. 8, when the electromagnetic solenoid is continuously energized, the temperature rises sharply and exceeds 100 ° C. in a short time. Also, 0.5
When the energization is repeated for 2.5 seconds / 2.5 seconds, the temperature rises to 100 ° C. in about 11 minutes. Then, as the energization ratio decreases, the degree of temperature rise decreases. Since the case 8 and the like of the electric door unit 7 provided with the electromagnetic solenoid 9 are made of synthetic resin, if the electromagnetic solenoid 9 exceeds 100 ° C., it may be thermally deformed.

FIG. 9 shows the degree of decrease in temperature when the electromagnetic solenoid is left in a state of being cut off (natural cooling). In the case of natural cooling, the descending speed changes exponentially according to the original temperature, but in order to simplify the data, it is divided into two stages of 80 ° C or higher and less than 80 ° C. It is assumed that the pressure decreases by 1 k (degree) in one minute (-1 k / min), and when the temperature is lower than 80 ° C., the pressure decreases by 0.3 k (degree) in one minute (-0.3 k / min).

FIG. 1 shows an example of a temperature change of the electromagnetic solenoid 9 when the door 2a is opened and closed, and FIG. 2 is a flowchart showing the control contents of the control circuit 30 at this time. The control circuit 30 converts the temperature data into a score (0.
1k is defined as one point), and the counter counts. First, the control circuit 30 reads data on the conditions of temperature rise and fall from a memory (not shown) (step S1). In this case, as the condition data, four points are added when the electromagnetic solenoid 9 is turned on once, and three points are subtracted when left below 80 ° C. for 1 minute, and 10 points when left above 80 ° C. for 1 minute. It is to subtract.

Next, an initial point is set (step S2). In this case, if the room temperature is 30 ° C., 30
X10 points are set to 300 points, and these 300 points are stored as initial points, and then a timer is set (step S3). Each time the user turns on the door opening switch 21 and the control circuit 30 turns on the electromagnetic solenoid 9, the four points are added and the subtraction is performed according to the time when the electromagnetic solenoid 9 is turned off (1). (If three minutes are left, three points are subtracted) (steps S4 to S11). Step S
At 10, the current point by the counter is compared with the current room temperature × 10. If the current point by the counter is equal to or larger than the current room temperature × 10, the process proceeds to step S5 according to “YES”. If the current point by the counter is smaller than the current room temperature × 10, the process proceeds to step S11 according to “NO”, where the current point is corrected to the current room temperature × 10,
Thereafter, the process proceeds to step S5.

Here, in children's pranks or in displays at stores, if the door 2a is frequently opened and closed and the electromagnetic solenoid 9 is frequently turned on, the temperature of the electromagnetic solenoid 9 gradually increases. Go (the current point by the counter increases). When the current point by the counter becomes 800 points or more (corresponding to 80 ° C. in temperature), in step S5, the process proceeds to step S12 in accordance with “YES”, and a subtraction point corresponding to the time when the electromagnetic solenoid 9 is turned off is set to three. Change from 10 points to 10 points. Even if the subtraction point is changed, if the current point by the counter increases and reaches 1000 points (corresponding to 100 ° C. in temperature, this 100 ° C. corresponds to the set value of the first and second aspects of the present invention). In step S4, "YE
The process moves to step S13 according to “S”.

When the current point of the counter reaches 1000 points, the operation of the electromagnetic solenoid 9 (electrically-operated door opening unit 7) is prohibited in step S15 through steps S13 and S14, and the display panel 19 is automatically operated. The display lamp of the door off is blinked to notify the user that the electric door unit 7 cannot be used. Thereafter, the process returns to step S13, and waits until the current point by the counter becomes less than 900 points. At this time, even if the user turns on the door opening switch 21, the control circuit 30 does not energize the electromagnetic solenoid 9, so that the temperature of the electromagnetic solenoid 9 gradually decreases and the current point by the counter gradually increases. Decreasing.

The current point by the counter is 9
If the score is less than 00, in step S13, "N
In accordance with "O", the process proceeds to step S16, the operation prohibition of the electromagnetic solenoid 9 is released, and the display lamp of the automatic door off on the display panel 19 is turned off, so that the electric door unit 7 can be used by the user. Notify that. Thereafter, the process proceeds to step S5. Then, when the electromagnetic solenoid 9 operates continuously again and the current point by the counter reaches 1000 points, the operation of the electromagnetic solenoid 9 is prohibited again in step S15, and the display lamp of the automatic door off on the display panel 19 blinks. Let it.

On the other hand, for example, the power-off time of the electromagnetic solenoid 9 becomes longer after the current point of the counter reaches 800 points, and when about three hours have passed since the electromagnetic solenoid 9 was last turned on, the electromagnetic solenoid 9 is turned off. Decreases until it is approximately equal to room temperature. Therefore, in step S9, it is determined whether three hours have elapsed since the electromagnetic solenoid 9 was last turned on, and if it is determined that three hours have elapsed, "YES" is determined in accordance with step S2.
Return to and set the initial point again. When the electric solenoid 9 is turned on again, the current point by the counter is adjusted again as described above.

According to the first embodiment, the following effects can be obtained. First, when the door opening switch 21 is operated, the electromagnetic solenoid 9 of the electric door unit 7 is energized and the electric door unit 7 is closed by the magnet gasket 2b.
, The door 2a can be opened against the attraction force of the magnet gasket 2b. As a result, the operating force required to open the door 2a can be greatly reduced, and even a weak person can use the door 2a.
a can be easily opened.

On the other hand, opening and closing of the door 2a (the electric door opening unit 7)
When the power supply to the electric door is continuously performed, the temperature of the electromagnetic solenoid 9 of the electric door unit 7 increases sharply. However, the temperature of the electric door unit 7 is set to a preset temperature (100 in this embodiment). ℃), the control circuit 3
0 temporarily inhibits the operation of the electric door opening unit 7, and until the temperature of the electric door opening unit 7 drops to a preset permission temperature (equivalent to 90 ° C. in this embodiment).
Is controlled not to operate again. For this reason, the electric door unit 9 can be prevented from rising to an abnormal temperature, and the case 8 made of synthetic resin of the electric door unit 9 can be prevented from being deformed by heat. become able to.

The electromagnetic solenoid 9 is provided with a protective temperature fuse 16 for melting at 130 ° C., which is used when the electromagnetic solenoid 9 cannot be controlled due to welding of the relay switch 27 or the like. The thermal fuse 16 must not be operated except in an emergency.

In the above-described embodiment, the temperature of the electric door opening unit 7 is estimated by converting a preset temperature rise degree and a temperature decrease degree into points and counting them by the counter of the control circuit 30. Since it is determined, there is no need to provide a circuit or the like for detecting the temperature of the electric door unit 7.

FIGS. 10 and 11 show a second embodiment of the present invention. The second embodiment differs from the first embodiment in the following points. That is, the control circuit 30
Indicates the temperature data as points (0.1k is one point)
The method of counting by the counter is the same as that of the first embodiment. However, when the current point by the counter reaches 1000 points, the operation of the electric door opening unit 7 is not completely prohibited, but the current point by the counter is When the score becomes 900 or more, the energization ratio is reduced by executing a permission / prohibition cycle in which the permission period for permitting the operation of the electric door unit 7 and the prohibition period for prohibiting the operation are repeated. Hereinafter, a specific description will be given.

The control circuit 30 first reads data on the conditions of temperature rise and fall from a memory (not shown) (step T1). In this case, as the condition data, if the temperature is lower than 90 ° C. (less than 900 points), the electromagnetic solenoid 9 is turned on once, 4 points are added, and if it is 90 ° C. or more (900 points or more), the electromagnetic solenoid is added. 9 turns on once, 2 points added, less than 80 ° C (800 points
If it is left for 1 minute (less than the point), 3 points are subtracted. If it is left for 1 minute at 80 ° C. or more (800 points or more), 10 points are subtracted.

Next, an initial point is set (step T2). Also in this case, assuming that the room temperature is 30 ° C., 3
A score of 0 × 10 points is set to 300 points, and these 300 points are stored as initial points, and then a timer is set (step T3). Each time the user turns on the door opening switch 21 and the control circuit 30 turns on the electromagnetic solenoid 9, the four points are added and the subtraction is performed according to the time when the electromagnetic solenoid 9 is turned off (1). 3 minutes if left
Point subtraction) (steps T4 to T9). Step T
At 8, the current point by the counter is compared with the current room temperature × 10, and the current point by the counter is
If it is equal to or greater than the current room temperature x 10,
The process proceeds to step T4 according to "YES", and if the current point by the counter is smaller than the current room temperature x 10, the process proceeds to step T9 according to "NO", and the current point is corrected to the current room temperature x 10 here. And after this,
Move to step T4.

When the door 2a is frequently opened and closed and the electromagnetic solenoid 9 is frequently turned on in children's mischief or at a store display, the temperature of the electromagnetic solenoid 9 gradually increases. Go (the current point by the counter increases). FIG. 10 shows lines when the electromagnetic solenoid 9 is turned on once every 3 seconds, when the electromagnetic solenoid 9 is turned on once every 10 seconds, and when the electromagnetic solenoid 9 is turned on once every 30 seconds. It is shown.

The current point by the counter is 8
When the temperature exceeds 00 points (corresponding to a temperature of 80 ° C.) or more, in step T4, the process proceeds to step T10 according to “YES”, and the subtraction point corresponding to the time during which the electromagnetic solenoid 9 is turned off is changed from 3 points to 10 points. . Even if the subtraction point is changed, the current point by the counter increases and 90
When the temperature reaches the zero point (corresponding to 90 ° C. in temperature, and this 90 ° C. corresponds to the set value of the first and third aspects of the present invention), in step T11, the process proceeds to step T12 according to “YES”. I do.

In step T12, the operation of the electric door unit 7 is restricted by limiting the period during which the ON operation of the door opening switch 21 is received. in this case,
The permission period for receiving the ON operation of the door opening switch 21 is 8 seconds, and the prohibition period is 25 seconds (permission / prohibition: 8 seconds / 25 seconds). When the ON operation of the door opening switch 21 is received during the permission period and the electromagnetic solenoid 9 is turned on, in step T13, the process proceeds to step T15 via step T14 according to "YES", adds two points, and returns to step T4. . Even if the period during which the ON operation of the door opening switch 21 is received is limited in this way, the current point by the counter increases and reaches 1000 points, and the process proceeds to step T16 according to "YES" in step T14. Here, the current point by the counter is 1
The process returns to step T4 while keeping the 000 points.

In this case, if the electromagnetic solenoid 9 is turned on three times during the permitted period of 8 seconds in a cycle of permission / prohibition: 8 seconds / 25 seconds, the ON time is 0.5
1.5 seconds per second / times × 3, OFF time is 25 seconds + 8 seconds−1.
5 seconds = 31.5 seconds, ON / OFF: 1.5 seconds / 3
1.5 seconds. This energization ratio is 0.5 in FIG.
Seconds / 10 seconds. In the case of an energization ratio of 0.5 seconds / 10 seconds, the temperature does not reach 100 ° C.
There is no safety problem even if the upper limit is set to 00 points.

By limiting the period during which the ON operation of the door opening switch 21 is accepted, a permission / prohibition cycle in which the permission period for permitting the operation of the electric door unit 7 and the prohibition period for prohibiting the operation are executed. And the energization ratio is reduced. When the current point by the counter decreases to less than 900 points, the restriction of step T12 is released.

In the second embodiment, the following effects can be obtained. That is, when the temperature of the electric door unit 7 rises to a preset set temperature (corresponding to 90 ° C. in this embodiment), an allowable period in which the operation of the electric door unit 7 is permitted and a prohibited period in which the operation is prohibited. By executing an allowance / prohibition cycle in which the above operation is repeated and restricting the operation of the electric door opening unit 7, it is possible to prevent the electric door unit 7 from rising to an abnormal temperature.

When the temperature of the electric door opening unit 7 rises to the set value, the electric door opening unit 7 cannot be operated during the prohibition period, but is operated when the permission period is reached. For example, in the case of storefront display, without waiting for a long time,
The electric door opening unit 7 can be operated, and the inconvenience of having to wait a long time can be solved.

The present invention is not limited to the above embodiments, but can be modified or expanded as follows. The temperature of the electric door unit 7 can also be obtained based on, for example, directly measuring the resistance value of the coil 11a of the electromagnetic solenoid 9, which is a driving source. Specifically, a constant low voltage (a level at which the electromagnetic solenoid 9 does not operate) is applied to the coil 11a, the current value is read, and the temperature of the electric door unit 7 is determined based on the current value. In such a case, the coil 1 in the electromagnetic solenoid 9 is
A temperature close to the actual temperature of 1a can be detected, and more accurate control can be performed.

The control circuit 30 is provided with an over-the-counter display mode.
The permission / prohibition cycle in which the permission period for permitting the operation and the prohibition period for prohibiting the operation are repeated may be always executed. In this case, in the storefront display mode, the permission / prohibition cycle is executed irrespective of the temperature of the electric door opening unit 7, so that the control of the control circuit 30 is simplified.

The drive source of the electric door unit 7 is not limited to the electromagnetic solenoid 9, but may be, for example, a linear motor type actuator or a motor combined with a speed reduction mechanism. The electric door opening unit 7
Instead of the refrigerator main body 1 side, it is also possible to provide it on the door 2a side.

[0051]

As is apparent from the above description, according to the present invention, the operation of opening the door against the attraction force of the magnet gasket can be performed by the electric door unit, and the door can be opened. In this case, it is possible to significantly reduce the operation force required for the operation, and to prevent the electric door unit from rising to an abnormal temperature beforehand.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of the present invention and shows an example of a temperature change (an example of a change in a point of a counter) of an electric door unit.

FIG. 2 is a flowchart showing control contents of a control circuit.

FIG. 3 is a front view of the refrigerator.

FIG. 4 is a perspective view of the refrigerator with a refrigerator compartment door opened.

FIG. 5 is a longitudinal sectional side view of a main part.

FIG. 6 is a plan view showing a part of the electric door opening unit in a cutaway manner.

FIG. 7 is an electrical configuration diagram of a main part.

FIG. 8 is a diagram showing a relationship between a power supply ratio of the electric door opening unit and a temperature change.

FIG. 9 is a diagram showing a temperature change when the electric door unit is left unattended.

FIG. 10 is a view corresponding to FIG. 1, showing a second embodiment of the present invention;

FIG. 11 is a diagram corresponding to FIG. 2;

[Description of References] 1 is a refrigerator main body, 2 is a refrigerator room, 2a is a door, 2b is a magnet gasket, 7 is an electric opening / closing unit, 9 is an electromagnetic solenoid, 11 is a coil unit, 11a is a coil, 13
Is a plunger, 14 is a push rod, 17 is a holder,
Reference numeral 20 denotes a handle, 21 denotes an opening switch, 22 denotes a DC power supply circuit, 27 denotes a relay switch, and 30 denotes a control circuit (control means).

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3L045 AA02 BA01 CA02 DA01 LA17 MA01 MA12 MA15 MA16 NA16 NA18 NA19 PA01 PA03 PA04 PA06 3L102 JA01 KA01 KB23

Claims (6)

[Claims] 1. A refrigerator provided with a door which is held closed by a magnet gasket, wherein the door exerts a force in an opening direction on the door upon being energized, thereby causing the door to exert an attractive force on the magnet gasket. An electric door unit for opening the electric door unit, and a control unit for controlling the operation of the electric door unit, wherein the control unit is configured to control when the temperature of the electric door unit rises to a preset value. A refrigerator for controlling the operation of the electric door unit. 2. The control means inhibits operation of the electric door unit when the temperature of the electric door unit rises to the set value, and lowers the temperature of the electric door unit to a preset permission temperature. The refrigerator according to claim 1, wherein the electric door unit is controlled so as not to be operated again. 3. A permission / prohibition cycle that repeats a permission period for permitting the operation of the electric door unit and a prohibition period for prohibiting the operation when the temperature of the electric door unit rises to the set value. 2. The refrigerator according to claim 1, wherein the operation is performed. 4. The refrigerator according to claim 1, wherein the temperature of the electric door unit is estimated and obtained by control means based on a preset degree of temperature rise and a degree of temperature decrease. 5. The electric door unit has an electromagnetic solenoid as a driving source, and the temperature of the electric door unit is obtained based on a measurement of a resistance value of a coil of the electromagnetic solenoid. The refrigerator according to claim 1. 6. The control means has a storefront display mode. In the storefront display mode, a permission / prohibition cycle in which a permission period for permitting the operation of the electric door opening unit and a prohibition period for prohibiting the operation are repeatedly executed. The refrigerator according to claim 1, wherein: