JPH0478907B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a refrigerator equipped with a damper opening/closing device that uses electrical input to adjust the amount of cold air into a refrigerator compartment.

Conventional technology A conventional example will be explained with reference to FIGS. 3 to 5.

Reference numeral 1 denotes a refrigerator body, which is divided by a partition wall 2 into a freezing compartment 3 at the top and a refrigerating compartment 4 at the bottom. Reference numeral 5 indicates a cooler for the refrigeration cycle, and reference numeral 6 indicates a blower for forced ventilation, which are respectively disposed within the partition wall 2. Reference numeral 7 denotes a temperature detector for the freezer compartment, such as a thermistor, which detects the temperature of the freezer compartment 3.

Reference numeral 8 denotes a damper opening/closing device (hereinafter referred to as an electric damper) installed at the entrance of the refrigerator compartment to adjust the amount of cold air flowing in according to electrical input, and is composed of a solenoid 9 and a damper flap that opens and closes the cold air passage operated by the solenoid. . 11 is the damper case,
An air passage section 11a is formed in the upper part, and a mechanical part 11b is formed in the lower part. 12 is a rod that pushes up the damper flap 10 in the opening direction;
1 through a part of the air passage section 11a and the mechanical section 11b.
The damper flap 10 communicates with the damper flap 10, and its tip abuts a part of the lower surface of the damper flap 10 whose upper end is pivotally supported by the air passage section 11a. Reference numeral 13 denotes a plunger connected to the rod 12, which is inserted into the inner core of the solenoid 9 housed in the mechanical part 11b and is movable up and down. A spring 14 normally biases the plunger 13 downward. Also 15
is a spring that biases the damper flap 10 in the closing direction. Reference numeral 16 denotes a temperature sensor for the refrigerator compartment, such as a thermistor, which detects the temperature of the refrigerator compartment 4.

With this configuration, the cold air cooled by the cooler 5 is forced into the freezer compartment 3 by the blower 6. Furthermore, cold air is introduced into the refrigerator compartment 4 via an electric damper 8.

Next, the electric circuit will be explained.

A refrigeration cycle compressor 17 is connected in parallel with the blower 6 and connected to a power source via a relay contact 18. The solenoid 9 of the electric damper 8 is connected in series with a relay contact 19 and connected to both ends of a power source. 20 is a freezing room temperature control device, which includes a temperature detector 7 such as a thermistor, resistors R ₁ , R ₂ ,
R ₃ , a comparison circuit including a comparator 21, a transistor 22, and a relay coil 18'.
The output of the comparator 21 is connected to the transistor 22
connected to the base of. Also, transistor 22
A suction relay coil 18' for opening and closing the relay contact 18 is connected to the collector. 2
Reference numeral 3 denotes a damper opening/closing control device, which includes a temperature detector 16 such as a thermistor for a refrigerator, resistors R ₄ , R ₅ , R ₆ , a comparator 24, a transistor 25, and a relay coil 19'.
The output of 4 is connected to the base of a transistor 25, and the collector of the transistor 25 is connected to a suction relay coil 19' that opens and closes the relay contact 19.
is connected.

In such a configuration, if the temperature of the freezing compartment 3 is higher than a predetermined value during normal operation, the temperature sensor 7 of the freezing compartment
The resistance value R _TH is decreasing, and this resistance value
The potential at point A determined by R _TH and resistance R ₁ is
Since the potential at point B becomes higher than the potential determined by R ₂ and R ₃ and the output of the comparator 21 becomes "H", the transistor 22 turns on and the relay coil 18' becomes conductive. Then, the relay contact 18 is closed and the compressor 17 and the blower 6 are operated to cool the freezer compartment 3 and the refrigerator compartment 4. Thereafter, when the freezer compartment 3 is cooled to a certain temperature, the resistance value R _TH of the temperature sensor 7 of the freezer compartment increases, and the A potential becomes smaller than the B potential, so the comparator 21 sends a low signal (hereinafter simply " (referred to as "L"). Therefore, the transistor 22 is turned OFF and conduction to the relay coil 18' is cut off, the relay contact 18 is opened, and the compressor 17 and the blower 6 are stopped. Also during this time, refrigerator room 4
Regarding temperature control, when the temperature of the refrigerator compartment 4 is higher than a predetermined value, the resistance value R _TH ′ of the temperature sensor 16 of the refrigerator compartment becomes small, and the resistance value C determined by R _TH ′ and the resistance R ₄ becomes smaller. The potential at the point becomes higher than the potential at point D determined by the resistors R ₅ and R ₆ , and the output of the comparator 24 becomes "H", so the transistor 25 turns on.
do. Then, the relay coil 19' becomes conductive, closing the relay contact 19, and the solenoid 9 of the electric damper 8 becomes conductive, so that the damper flap 10 is opened and cold air flows into the refrigerator compartment 4 to cool it. After that, when the temperature of the refrigerator compartment 4 is cooled to a constant temperature, the resistance R _TH ' of the temperature sensor 16 of the refrigerator compartment becomes large, and the C potential becomes smaller than the D potential, so the output of the comparator 24 becomes "L". Therefore, the transistor 25 is turned off. Then, conduction to the relay coil 19' is cut off and the relay contact 19 is opened.
The conduction to the solenoid 9 is also cut off, and the damper flap 10 is closed to prevent cold air from flowing into the refrigerator compartment 4. In this way, the temperature control of the refrigerator compartment 4 is not influenced by the temperature control action of the freezing compartment 3 and is independently controlled. Thereafter, this action is repeated to perform the normal cooling action.

Problems to be Solved by the Invention However, during the cooling operation of the refrigerator compartment 4, when the compressor 17 and the blower 6 are stopped, the air containing humidity at a positive temperature in the refrigerator compartment 4 is moved by natural convection to the electric damper. Cold air may flow back into the cold air passage section 11a of 8, especially when a considerable amount of moisture-rich food is stored in the refrigerator compartment 4, or when the door is opened and closed frequently, resulting in a large amount of outside air flowing in. The moisture level in the backflow air is extremely high, and the damper case 11 when the damper flap 10 is closed.
If dew condensation occurs on the contact surface with the damper case 11 and the gap between the damper case 11 and the top surface when the damper flap 10 is opened, and the condensed water freezes while the damper flap 10 is closed, the damper flap 1
Since the solenoid 0 remains in contact with the damper case 11 and fixed, the solenoid 9 becomes normal and the rod 12
Even if the user attempts to push up the damper flap 10, the damper flap 10 will not open, and the desired cold air will not be supplied to the refrigerator compartment 4, causing the temperature to rise and the cooling function of the refrigerator compartment 4 to be lost. Something happened. On the other hand, if the condensed moisture freezes while the damper flap 10 is being opened, the damper flap 10 will become stuck to the top surface of the damper case 11, the solenoid 9 will be de-energized, and the rod 12 will be pushed down. However, the damper flap 10 remains open and is not closed, and the function to adjust the amount of cold air to the refrigerator compartment 4 is lost, causing the refrigerator compartment 4 to become overcooled and the stored food to be frozen. It was hot too.

In view of the above-mentioned points, the present invention aims to prevent the damper flap of the damper opening/closing device from freezing and sticking to the damper case and losing its temperature regulating function.

Means for Solving the Problems In order to achieve this object, the present invention provides a damper flap of a damper opening/closing device which, in addition to the normal opening/closing operation, can be electrically controlled to perform extremely short opening/closing operations at predetermined intervals. A damper opening/closing device is installed to repeat this process.

Therefore, the present invention prevents the moisture adhering to the damper flap from continuously freezing and solidifying on the damper case, and eliminates most of the adhering moisture from repeated mechanical opening and closing operations of the damper flap. This prevents the damper flap from freezing and sticking by shaking it off.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Incidentally, the same components as those in the prior art are given the same reference numerals, and detailed explanation thereof will be omitted.

23' is a damper opening/closing control device, which includes a temperature detector 16 for the refrigerator compartment, resistors R ₄ , R ₅ , R ₆ , a comparator circuit including a comparator 24, and a transistor 25;
Relay coil 19', timer device 26, pulse generator 27, inverter 28, AND circuit 2
9 and 30, the comparator 24
The output of is connected to one input of the AND circuit 29. Further, the output of the timer device 26 is branched, and one side is connected to the AND through an inverter 28.
connected to the other input of the circuit, the other is AND
It is connected to one input of the circuit 30. The output of the pulse generator 27 is connected to the input of the other input of the AND circuit 30, and the output of the pulse generator 27 is connected to the other input of the AND circuit 30.
The outputs of the circuit 29 and the AND circuit 30 are both connected to the base of the transistor 25. Further, an attraction coil 19' for opening and closing the relay contact 19 is connected to the collector of the transistor 25.

Here, the output of the timer device 26 is predetermined as shown in FIG. The output of the pulse generator 27 is configured to constantly repeat "H" and "L" at very short intervals (for example, 1 second) at a constant period, as shown by ◯ in FIG.

Next, the operational status of this configuration will be explained.

Note that the freezing compartment and cooling operation are the same as in the prior art, and therefore their explanation will be omitted, and the operation of the refrigerator compartment will be described. The normal cooling operation of the refrigerator compartment 4 is the same as the conventional one, and the output of the comparator 24 (○B in Figure 2) is determined according to the temperature characteristics of the temperature detector 16 in the refrigerator compartment (○B in Figure 2), and the electric damper 8 damper flaps 10 perform normal cooling action by opening and closing operations.

On the other hand, at this time, the output of the timer device 26 is transmitted to the inverter 28 connected to it in order to emit an "H" signal for a predetermined short time (for example, 10 seconds) every predetermined period, as shown in ○C in FIG. The output of is inverted as shown in ○D in FIG. 2 and input to one side of the AND circuit 29. Therefore, the output of the AND circuit 29 becomes the AND of ○B and ○D in FIG. 2, and becomes the output of ○H in FIG. On the other hand, the pulse generator 27 constantly repeats "H" and "L" output every very short time (for example, 1 second) as shown in ○ in FIG. 2, and outputs the output to one side of the AND circuit 30. On the other hand, the second output of the timer device 26
Since ○C in Figure 2 is also input at the same time, the output of the AND circuit 30 is ANDed between the two, and the output is outputted every predetermined period for a very short time (for example, 1 second) as shown in Figure 2○G.
“H” and “L” will be repeated.

Therefore, as shown in Figure 2, the input signal actually input to the base of the transistor 25 is transmitted for a very short period of time (for example, 1 second) when it reaches a predetermined period, regardless of the state of the output ○ and b of the comparator 24. ) “H”,
A repeating signal of the "L" signal will interrupt.
Therefore, if the comparator 24 is outputting an "H" signal when a predetermined cycle is reached, first, for example, an "L" signal is output for one second to turn off the transistor 25. Therefore, the relay coil 19' is cut off from conduction, the relay contact 19 is opened, and the energization to the solenoid 9 of the electric damper 8 is also stopped. When the energization to the solenoid 9 is stopped, the force pushing the plunger 13 upward is eliminated, and the plunger 13 falls downward together with the restoring action of the spring 14, and is also pulled down by the rod. When the rod 12 is no longer pushed up, the damper flap 10 is mechanically pulled down together with the tensile action of the spring 15. In the next second, an "H" signal is generated and the transistor 25 is activated.
Turn it on. Therefore, the relay coil 19' is made conductive, the relay contact 19 is closed, and the solenoid 9 of the electric damper 8 is energized. When the solenoid 9 is energized, the plunger 13 is inserted into the inner core.
is pushed upward by electromagnetic action, and the spring 14
is compressed to push up the rod 12 and mechanically open the damper flap 10 in contact with it. Thereafter, for example, this opening/closing operation every second is repeated a predetermined number of times.

On the other hand, if the comparator 24 is outputting an "L" signal when the predetermined cycle is reached, first, for example, a "H" signal is output for one second to turn on the transistor 25, and then for the next one second, the comparator 24 outputs an "L" signal. The "L" signal is generated to turn off the transistor 25, which is then repeated several times, and as described above, the opening/closing operation of the damper flap 10 is repeated a predetermined number of times every second.

In this way, the output of the comparator 24 at that time, that is, the damper flap 10 of the electric damper 8
Regardless of whether the compressor 17 is closed or open, the damper flap is repeated a predetermined number of times at very short intervals at predetermined intervals, and the refrigerating compartment is closed while the compressor 17 is stopped. Even if the humid air inside the electric damper 8 flows back into the cold air passage section 11a of the electric damper 8 and condenses on the damper flap 10 or the damper case 11 that is close to or in contact with it, this can occur in the extremely short period described above. Since the damper flap 10 is forcibly opened and closed at time intervals, there is no resting time for the attached moisture to freeze, and the lower part of the moisture is forced to open and close the damper flap 10.
This prevents the damper flap 10 from being shaken off by the mechanical opening/closing operation of 0, and the damper flap 10 becoming stuck to the damper case 11 due to the freezing of water, causing malfunction of the refrigerator compartment 4 due to no cooling or freezing. can be prevented. Note that this opening/closing operation is an extremely short-time operation and does not affect the normal temperature control operation at all.

Effects of the Invention As is clear from the above description, the present invention provides a damper opening/closing device that adjusts the amount of cold air flowing into the refrigerating compartment entrance of a forced draft refrigerator by electrical input, and a damper flap of the damper opening/closing device. A damper opening/closing control device which controls opening/closing according to the temperature of the refrigerator compartment and repeats a short opening/closing operation of the damper flap at least once or more every predetermined cycle irrespective of the opening/closing control according to the temperature of the refrigerator compartment. Therefore, even if the humid air in the refrigerator compartment flows back and condenses around the damper flap while the compressor is stopped, the moisture can be removed by repeatedly controlling the damper flap to open and close. Since the damper flaps are not given enough time to stand still before freezing, and the adhering moisture is mechanically shaken off, the damper flaps may freeze and stick, causing the refrigerator compartment to lose its cooling function while remaining closed, or to open. It can prevent food in the refrigerator from freezing if left unattended.
The effectiveness of its implementation is extremely high.

[Brief explanation of the drawing]

Fig. 1 is a control circuit diagram of a refrigerator showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation of the control circuit of Fig.
FIG. 5 is an enlarged sectional view of a damper opening/closing device provided in the refrigerator shown in the figure, and FIG. 5 is a control circuit diagram of a conventional refrigerator. 5...Cooler, 6...Blower, 8...Damper opening/closing device, 10...Damper flap, 23'...
...Damper opening/closing control device.

Claims (1)

[Claims] 1. A blower that circulates the air cooled by the cooler of the refrigeration cycle to the freezer compartment and the refrigerator compartment, a damper opening/closing device that adjusts the amount of cold air to the refrigerator compartment by electrical input, and a damper flap of the damper opening/closing device that A damper opening/closing control device that controls opening/closing according to the room temperature and repeats a short opening/closing operation of the damper flap at least once every predetermined period, regardless of the opening/closing control according to the temperature of the refrigerator compartment. A refrigerator consisting of a