JPS5813259Y2 - refrigerator - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a refrigerator equipped with a convection fan that is controlled independently of the refrigeration cycle.

The current mainstream refrigerators are fan type (cool air forced convection type) and direct cooling type (cold air natural convection type).

While the fan type has the advantage of small temperature differences within the refrigerator, making it difficult for food to become frosty, it takes a long time to make ice, and it also requires an attached device that incorporates cold air passages and dampers that interrupt the flow of cold air. It has the following drawbacks.

Furthermore, the direct cooling type has the advantage of short ice making time and low power consumption, but has the disadvantage of large temperature differences within the refrigerator, so both types have advantages and disadvantages.

The present invention combines the advantages of the fan type and direct cooling type by providing a convection fan and its control circuit in a conventional direct cooling type refrigerator.

In other words, it has an intermediate function between a fan type and a direct cooling type.

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

FIG. 1 is a sectional view of the refrigerator of the present invention, and FIG. 2 is an electrical connection diagram of the refrigerator of the present invention.

1 is the refrigerator body, 2 is a condenser, and 3 is a compressor that is the heart of the refrigeration cycle.

4 is a refrigerator door, 5 is a top plate, 6 is a handle for opening and closing the door, 7 is an inner door provided to prevent cold air from escaping from the evaporator,
9 is a convection fan for convection of cold air inside the refrigerator, and 8 is a fan motor.

10.11 is a temperature detection unit provided at the upper and lower parts of the refrigerator; 12. 14 indicates a vegetable basket, and 14 indicates a hinge portion of the door 4.

Next, the electrical connection diagram shown in FIG. 2 will be explained.

15 is a power plug to be inserted into a commercial power outlet, 19
20 is a temperature control thermostat, 20 is a starting relay and an overload relay, 21.22 is a drive coil and a starting relay contact that make up the starting relay, and 23 and 24 are a heater and an overload relay contact that make up the overload relay.

Reference numeral 25 indicates a starting capacitor, and reference numeral 17 indicates an interior light switch that is linked to opening and closing of the refrigerator door 4.

Reference numeral 18 indicates an interior light that turns on when the door 4 is open, and 27 indicates a relay contact that detects the temperature of the upper and lower parts of the interior 13 and when the temperature difference between the two exceeds a predetermined value. 1
6 is turned on, and controls the relay contact 16 to be turned off when the temperature difference is below a predetermined value.

FIG. 3 shows an example circuit of the control section 27.

31 is a power transformer, 32 is a protection resistor, 33 is a rectifier, and 34 is a capacitor, which constitutes a well-known circuit for extracting DC voltage.

35 and 36 are voltage divider resistors directly connected between the output terminals, and this voltage dividing point is connected to the DC amplification transistor 38 via the temperature detection section 10.

A resistor 39 is connected between the emitter of the transistor 38 and the ground, and a DC voltage is applied to the collector.

Further, a variable resistor 37 for temperature setting is connected between the base and ground.

35', 36', 37', 38', and 39' are the same components as those mentioned above with the symbols without a dash.

Each emitter of transistor 38, 38' is connected to comparator circuit 28.
The output terminal of the comparison circuit 28 is connected to the switching circuit 29.

The output terminal of the switching circuit 29 is grounded through the drive coil 30 of the relay.

Temperature detection units 10 and 1 provided at the upper and lower parts of the refrigerator
1 uses a thermistor whose resistance value changes as the temperature rises.

In the circuit configuration shown in FIG. 3, the resistance of the thermistor 10 changes depending on the temperature inside the refrigerator, and the base potential of the transistor 38 changes.

As a result, the current flowing through the emitter resistor 39 changes, and the emitter voltage e1 applied to the comparison circuit 28 changes.

Similarly, since the emitter voltage e2 of the transistor 38' is also applied, the comparator circuit 28 detects the voltage e1. Compare e2 and take out the difference output e1-e2.

Here, when el-e2, the output of the comparison circuit 28 becomes zero.

At the time of e2set, an output voltage with a difference value is generated, and when the value is equal to or higher than a predetermined set value, the switching circuit 29
is turned on, and the drive coil 30 is excited.

This turns on the relay contact 16, causing the fan motor 8 to rotate.

Further, when the output voltage of the circuit 29 is below a set value, the relay contact 16 is turned off.

That is, the rotation of the fan motor 8 is controlled independently of the refrigeration cycle in response to the temperature difference between the upper and lower parts of the refrigerator.

According to the above configuration, a conventional direct cooling refrigerator is equipped with a convection fan and a fan motor that force convection of cold air independently of the refrigeration cycle, and a full-fledged fan that is controlled by the temperature difference between the upper and lower parts of the refrigerator. To obtain a refrigerator that incorporates the advantages of a direct cooling type and a fan type without requiring a complicated configuration like a type refrigerator.

Recent customer trends require accurate temperature display inside the refrigerator, and the natural convection type had the disadvantage that the temperature difference inside the refrigerator was large and it was not possible to accurately display the temperature. Since the temperature becomes uniform, this problem can also be solved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a refrigerator that is an embodiment of the present invention, FIG. 2 is an electrical connection diagram of the refrigerator of FIG. 1, and FIG. 3 is a circuit diagram of an embodiment of the control section 27. Here, 9... Convection fan, 16...
Relay contact, 10.11...Temperature detection section, 28
. . . Comparison circuit, 29 . . . Switching circuit.

Claims (1)

[Scope of utility model registration request] A convection fan that forcibly circulates cold air inside the refrigerator independent of the refrigeration cycle, a relay contact that controls on/off energization of the convection fan, and temperature-dependent elements installed separately at the upper and lower parts of the refrigerator. a temperature detection section that detects an electrical change in response to a temperature change; a comparison circuit that outputs an output proportional to the difference between the outputs of the two detection sections; and a switching circuit that operates to turn on the relay contact and turn off the relay contact when the differential output is equal to or greater than the predetermined value.