JPH048710B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a refrigerating room temperature control device for a refrigerator-freezer, which is equipped with a damper opening/closing control device that uses electrical input to adjust the amount of cold air into the refrigerating room.

Conventional configuration and its problems A conventional example will be explained with reference to FIGS. 1 to 3.

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.

8 is a damper opening/closing device (hereinafter referred to as an electromagnetic damper) installed at the entrance of the refrigerator compartment to adjust the amount of cold air flowing in according to electrical input, and a solenoid (driving means) 9
and a damper flap 10 which opens and closes the cold air passage operated by the solenoid 9. 11
1 is a damper case, which has an air passage section 11a in the upper part and a mechanical part 11b in the lower part. 12 is a rod that pushes up the damper flap 10 in the opening direction;
It penetrates a part of the damper case 11 and communicates with the air passage part 11a and the mechanical part 11b, and its tip touches a part of the lower surface of the damper flap 10 whose upper end is pivotally supported by the air passage part 11a. are in contact with each other. 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. 14 is a spring,
Normally, the plunger 13 is biased downward. A spring 15 biases the damper flap 10 in the closing direction. Reference numeral 16 denotes a temperature sensor (first 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 the electromagnetic damper 8.

Next, the electric circuit will be explained.

Reference numeral 17 denotes a compressor of the refrigeration cycle, which is connected in parallel with the blower 6 and then connected to a power source via a relay contact 18. The solenoid 9 of the electromagnetic damper 8 is a relay contact (damper drive contact) 19.
and then connected in series with both ends of the power supply. Reference numeral 20 denotes a cooling room temperature control device, which includes a temperature detector 7 such as a thermistor, resistors R ₁ , R ₂ , R ₃ , a comparator circuit including a comparator 21, a transistor 22, and a relay coil 18'. The output of 21 is connected to the base of transistor 22. Further, an attraction relay coil 18' for opening and closing the relay contact 18 is connected to the collector of the transistor 22. 23 is 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,
The output of the comparator 24 is connected to the base of the transistor 25, and the collector of the transistor 25 is connected to the suction relay coil 19' for opening and closing the relay contact 19. ing.

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 is turned on.
do. Then, the relay coil 19' becomes conductive, closing the relay contacts, and the solenoid 9 of the electromagnetic 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 down to a constant temperature, the resistance R _TH ' of the temperature sensor 16 of the refrigerator compartment increases, and C
Since the potential becomes smaller than the D potential, the output of the comparator 24 becomes "L", and the transistor 25 becomes
Turn off. Then, since the 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, causing the damper flap 1 to open.
0 closes 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.

However, in this way, the refrigerator temperature sensor 16
When controlling the opening/closing amount of the damper flap 10 of the electromagnetic damper 8 based on the temperature signal detected by the
Since the damper flap 10 is opened and closed within a certain set temperature range regardless of changes in outside temperature conditions, the amount of heat absorption load entering the refrigerator body 1 decreases as the outside temperature decreases relatively. As a result, the balance between the required amount of cooling and the amount of heat absorption load is disrupted, resulting in a supercooled state, and even if there is no cold air supplied to the refrigerator compartment 4, as in the case where the outside air temperature is approximately 0 to 5 degrees Celsius, the refrigerator compartment 4 may not operate as it should. Even if the function described above can be achieved, there is a disadvantage that the indoor temperature of the refrigerator compartment 4 becomes negative temperature due to the supply of cold air into the refrigerator compartment 4, and the food in the room freezes.

Purpose of the Invention In view of the above points, an object of the present invention is to prevent freezing inside a refrigerator compartment under low outside temperatures.

Structure of the Invention In order to achieve this object, the present invention prevents unnecessary overcooling of the inside of the refrigerator compartment by forcibly closing a damper for regulating the amount of cold air inflow under low outside temperatures. It is intended to prevent

DESCRIPTION OF EMBODIMENTS FIGS. 4 to 6 show an embodiment of the present invention.
This will be explained according to the diagram. 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 sensor 16 for the refrigerator compartment, resistors R ₄ , R ₅ , R ₆ , and a comparator 24 . The output terminal of the comparator 24 is connected to an AND circuit (damper drive determination means) 26 is connected to one input terminal of the AND circuit 2
The output terminal of the transistor 25 is connected to the base terminal of the transistor 25, and a reel coil 19' is inserted between the collector terminal of the transistor 25 and the power supply. Reference numeral 27 denotes an outside air temperature detection device, which includes a temperature detector (second temperature detector) 28, resistors R ₇ , R ₈ , R ₉ , and a comparator 29, and the output of the comparator 29 is the other input of the AND circuit 26. It is connected to the. Further, the output of the AND circuit 26 is connected to the base of the transistor 25, and the output of the AND circuit 26 is connected to the base of the transistor 25.
A suction relay coil 19' for opening and closing the relay contact 19 is connected to the collector 5.

Note that the resistances R ₇ , R ₈ ,
The resistance value of _R9 is determined so that the output of the comparator 29 is inverted from H to L when the outside temperature is approximately 5° C. or lower.

Next, the operational status of this configuration will be explained.
Note that the cooling operation of the freezer compartment during normal operation is the same as the conventional one, and the explanation thereof will be omitted, and the cooling operation of the refrigerator compartment will be explained. Refrigerator compartment 4 when the outside temperature is approximately 5℃ or higher
If the temperature of
R _TH ′ is becoming smaller, and the potential at point C′ determined by R _TH ′ and R ₄ becomes higher than the potential at point D determined by resistors R ₅ and R ₆ , and the output of comparator 24 becomes “H”. ”, so one input of the AND circuit 26 becomes “H”. In addition, since the outside air temperature is approximately 5°C or higher, the resistance value R _TH ″ of the temperature sensor 28 of the outside air temperature detection device 27 is small, and the potential at point E determined by R _TH ″ and R ₇ is F determined by R ₈ and R ₉
Since the potential of the point is higher than that of the point and the output of the comparator 29 is "H", the other input of the AND circuit 26 is also "H", and therefore the AND
The output of the circuit 26 becomes "H" and the transistor 25
turns on. Then, in order to conduct the relay coil 19' and close the relay contact 19, the solenoid 9 of the electromagnetic damper 8 is energized. When the solenoid 9 is energized, the plunger 13 inserted inside the solenoid is pushed upward by electromagnetic action, compressing the spring 14 and pushing up the rod 12, opening the damper flap 10 in contact with it and releasing cold air. An air passage portion 11a is formed. As a result, the cold air generated by the cooler 5 is supplied to the inside of the refrigerator compartment 4 by the forced air blower 6 for cooling. Thereafter, when the temperature of the refrigerator compartment 4 is cooled to a certain temperature, the resistance value 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 comparator 24
Since the output of the AND circuit 26 becomes "L" and one input of the AND circuit 26 becomes "L", the output of the AND circuit 26 becomes "L" regardless of the other input, and the transistor 25 turns OFF. Therefore, the relay coil 19' is disconnected, the relay contact 19 is opened, and the energization to the solenoid 9 of the electromagnetic damper 8 is also stopped. When the energization to the solenoid 9 is stopped, the force pushing the plunger 13 upward is eliminated, the plunger 13 falls downward together with the restoring action of the spring 14, and the rod 12 is also pulled down. When the rod 12 is no longer pushed up, the damper flap 10 is pulled down together with the tensile action of the spring 15, and the cold air passage 11a is closed, blocking the inflow of cold air into the refrigerator compartment 4. Thereafter, this action is repeated to perform a normal cooling action.

Next, a case where the outside air temperature drops to approximately 5° C. or lower will be described.

When the outside air temperature decreases, the resistance value R _TH '' of the temperature sensor 28 of the outside air temperature detection device 27 increases, and when it further decreases to approximately 5° C. or less, the potential at point E determined by R _TH '' and the resistor R ₇ becomes Since the potential of point F is lower than the potential determined by resistors R ₈ and R ₉ and the output of the comparator 29 becomes "L", one input of the AND circuit 26 becomes "L" and the AND circuit becomes "L" regardless of the other input.
The output of the circuit 26 becomes "L" and the transistor 2
5 is OFF. Therefore, the relay coil 19' is disconnected, the relay contact 19 is opened, and the energization to the solenoid 9 of the electromagnetic damper 8 is also stopped. When the energization to the solenoid 9 is stopped, the damper flap 10 is pulled down and the cold air passage section 11a is closed, thereby blocking the inflow of cold air into the refrigerator compartment 4.
As a result, it is possible to prevent the refrigerator compartment 4 from being unnecessarily overcooled and the food inside to freeze when the outside temperature is low, such as when the outside air temperature is approximately 5° C. or lower.

Effects of the Invention As is clear from the above configuration, the present invention includes an outside air temperature detection device that compares the outside air temperature input from the second temperature sensor with a predetermined temperature and outputs a signal to the damper drive determination means. The drive determination means is configured to output a signal for opening the damper flap of the damper opening/closing device only when the temperature of the refrigerator compartment is higher than the set temperature and the outside air temperature is higher than the predetermined temperature. Because the active cooling function of the refrigerator is not required under low outside temperatures, cold air will not flow into the refrigerator compartment unnecessarily and overcooling will occur, so food inside the refrigerator compartment is guaranteed to be protected against freezing at outside temperatures of approximately 0°C. Its effectiveness is extremely high when it is used in cold regions and during winter.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional refrigerator, Fig. 2 is a sectional view of the damper opening/closing device shown in Fig. 1, Fig. 3 is a control circuit diagram of Fig. 1, and Fig. 4 is a part of the present invention. FIG. 5 is a sectional view of the damper opening/closing device shown in FIG. 4, and FIG. 6 is a control circuit diagram of the refrigerator shown in FIG. 4. 5... Cooler, 6... Blower, 10... Damper flap, 23'... Damper opening/closing control device,
27...Outside temperature detection device.

Claims (1)

[Claims] 1. A damper opening/closing device provided at the opening of the duct in the refrigerator compartment that guides cold air from the cooler into the refrigerator compartment, and comprising a damper flap and a drive means for driving the damper flap, and a first temperature control device provided in the refrigerator compartment. A damper opening/closing control means for outputting a signal by comparing the refrigerator compartment temperature detected by the first temperature detector with the refrigerator compartment set temperature, and a second temperature detector provided outside the refrigerator; An outside air temperature sensing device that compares the outside air temperature detected by the second temperature sensor with a predetermined temperature and outputs a signal, and signals from the damper opening/closing control means and the outside air temperature sensing device are input, and the temperature of the refrigerator compartment is determined. outputting a signal to open a damper drive contact inserted in series in an electric circuit connecting a power source and the drive means only when the temperature is higher than the set temperature and the outside temperature is higher than the predetermined temperature;
and a damper drive determining means for opening the damper flap.