JPH04257680A - Refrigerator - Google Patents

Abstract

PURPOSE:To prevent a control switch used in controlling a compressor in a refrigeration chamber from being turned off during a defrosting operation and further to prevent a defrosting time from being extended. CONSTITUTION:A compensation heater 30 is provided to heat a heatsensitive part of a control switch 28 comprised of a thermostat and the heater 30 is connected in series with a defrosting heater 26. As a movable contact point of a changing-over switch 32b in a defrosting timer 32 is changed over to a state in which the contact points (c) and (b) are connected to each other, an electrical energization passage of the defrosting heater 26 is formed to perform a defrosting operation. At this time, since the heat-sensitive part of the control switch 28 is heated by the compensation heater 30, the control switch 28 is not turned off.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator in which a compressor is controlled to be turned on and off depending on the temperature of a refrigerator compartment.

0003

[Prior Art] Figure 5 shows the conventional configuration of this type of refrigerator.
This will be explained with reference to FIG. A control switch 2 consisting of a thermostat switch is installed in the refrigerator compartment 1a of the refrigerator 1.
It is configured to turn on when the temperature sensed by the heat sensitive part 2a is, for example, above +8 degrees, and turn off when it falls below +5 degrees.
It is connected to one bus bar 3a of the AC power supply 3. The heater 4 for ensuring temperature inside the refrigerator is connected to the bus bar 3a in parallel with the control switch 2, and is energized when the control switch 2 is turned off, heating the heat sensitive part 2a and turning on the control switch 2. It is set in.

[0004] The defrosting timer 5, which is composed of a timer motor 5a and a changeover switch 5b, normally has a movable contact of the changeover switch 5b connecting the contacts c and a as shown by the solid line to form an energizing path for the compressor 6. The movable contact of the changeover switch 5b is switched to connect the contacts c and b every time a certain period of time elapses, thereby forming an energizing path for the defrosting heater 8 via the bimetal 7.

[0005] When comparing the resistance value of the heater 4 for ensuring internal temperature and the resistance value of the defrosting heater 8, the resistance value of the heater 4 for ensuring internal temperature is higher than the resistance value of the defrosting heater 8. It is set quite large.

In the normal mode, the changeover switch 5b is in a state where contacts ca and a are connected, and when the control switch 2 is in the on state, the compressor 6 is driven and the fan 9 is turned on. driven,
Cool air from the cooler 10 is supplied to the freezer compartment 1b and the refrigerator compartment 1a to perform a cooling operation.

[0007] When the temperature sensed by the heat-sensitive portion 2a of the control switch 2 falls below +5 degrees, the control switch 2 is turned off as shown by the two-dot chain line, and the heater 4 for ensuring the temperature inside the refrigerator is energized. Then, since the resistance value of the heater 4 for guaranteeing the temperature inside the refrigerator is large, the compressor 6 becomes de-energized, and the fan 9 is also de-energized and the cooling operation is stopped. Then, when the temperature of the refrigerator compartment 1a gradually rises and the temperature sensed by the heat sensitive section 2a reaches +8 degrees or higher, the control switch 2 is turned on and the cooling operation is started again. In this way, the temperatures of the freezer compartment 1b and the refrigerator compartment 1a are controlled (see area A in FIG. 7).

[0008]

On the other hand, after the normal mode has been operated for a certain period of time, when the movable contact of the changeover switch 5b in the defrosting timer 5 is switched to a state where the contacts c and b are connected (as indicated by the two-dot chain line). ), the defrost heater 8 is energized and the defrost mode is performed. Note that the defrosting mode is always started when the control switch 2 is turned on.

When this defrosting mode is started (see point B in FIG. 7), the temperature of the cooler 10 gradually increases as the cooler 10 is heated by the defrosting heater 8.

At this time, for example, if the external temperature of the refrigerator 1 is low, or if cold air from the cooler 10 side flows into the control switch 2 side, the control switch 2
may be cooled, and the control switch 2 may be turned off from the on state (see point C in FIG. 7). When the control switch 2 is turned off in this way, the heater 4 for guaranteeing the internal temperature becomes energized, while the heater 4 for guaranteeing the internal temperature
Due to the relationship between the resistance value of the defrost heater 8 and the resistance value of the defrost heater 8, almost no voltage is applied to the defrost heater 8, and since the defrost heater 8 generates almost no heat, defrosting is temporarily suspended (see Fig. (See area D in 7). This state continues until the control switch 2 is turned on.

When the temperature sensed by the heat sensitive part 2a of the control switch 2 reaches +8 degrees or more, the control switch 2 is turned on (see point E in FIG. 7), and the heater 4 for guaranteeing the temperature inside the refrigerator is turned off. At the same time, the defrosting heater 8 is turned on, and the cooler 10 is defrosted again.

When the temperature of the cooler 10 reaches the defrosting completion temperature, the bimetal 7 is turned off, and accordingly, the timer motor 5a is temporarily energized and the contact c of the changeover switch 5b is turned off.
-a is connected to the normal mode (see point F in FIG. 7), and the cooling operation is performed again.

As described above, in the above configuration, the control switch 2 may be temporarily turned off in the defrosting mode, and in such a case, the defrosting is temporarily interrupted until the control switch 2 is turned on again, resulting in In particular, there is a problem in that the time from the start to the end of defrosting (between B and F in FIG. 7) becomes long.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a refrigerator that can prevent the control switch from turning off when the defrosting mode is started, thereby preventing the time from the start to the end of defrosting from becoming longer. It is on offer.

[Configuration of the invention]

[0016]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a control switch that controls the power supply and disconnection of a compressor by turning it on and off based on the temperature detected by a heat-sensing section provided in a refrigerating room; In a refrigerator equipped with a defrosting heater provided to defrost the cooler by heating the cooler in an energized state, and a defrosting circuit forming an energizing path for the defrosting heater based on predetermined conditions. A security heater is provided which becomes energized when the defrosting circuit forms an energizing path for the defrosting heater and heats the heat-sensitive portion of the control switch.

[0017]

[Function] When the defrost circuit forms an energizing path for the defrost heater, the security heater also becomes energized at the same time, and the security heater heats the heat-sensitive part of the control switch, so the defrost mode is activated. The control switch will never turn off.

[0018]

Embodiment A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3. First, in FIG. 2, a freezer compartment 22 and a refrigerator compartment 23 are formed vertically inside a refrigerator main body 21, and a cooler 24 and a fan 25 are provided at the back of the freezer compartment 22.
A defrosting heater 26 is also provided below the cooler 24.

A case 27 is attached to the side wall of the refrigerator compartment 23, and a control switch 28 consisting of a thermostat switch is disposed within the case 27. The control switch 28 is configured to be turned on when the temperature sensed by the heat sensitive portion 28a is, for example, above +8 degrees, and turned off when the temperature is below +5 degrees. Also, case 2
7 contains a heater 29 for guaranteeing the temperature inside the refrigerator and a heater 3 for guaranteeing the temperature inside the refrigerator.
0, and both heaters 29 and 30 heat the heat-sensitive portion 28a of the control switch 28 when energized.

FIG. 1 shows an electrical configuration related to the gist of the present invention. In the figure, the control switch 28 is connected to one bus bar 31a of a 100V AC power supply 31. In addition, the heater 29 for guaranteeing the temperature inside the refrigerator has a control switch 28 on the bus bar 31a.
are connected in parallel.

[0021] Timer motor 32a and changeover switch 32
The defrost timer 32 consisting of
The movable contact b connects the contacts c and a as shown by the solid line to form an energizing path for the compressor 33, and the movable contact of the changeover switch 32b connects the contacts c and b every time a certain period of time elapses. By switching to , an energizing path for the defrosting heater 26 is formed via the bimetal 34 . Here, the defrost timer 32 and the bimetal 34 constitute a defrost circuit 35.

The security heater 30 is connected in series with the defrost heater 26 between the defrost circuit 35 and the other bus bar 31b of the AC power supply 31. In addition, the security heater 3
The resistance value of 0 is set to be smaller than the heater 29 for ensuring internal temperature and larger than the defrosting heater 26.

Next, the operation of the above configuration will be explained with reference to FIG. 3 as well. In normal mode, selector switch 3
2b is in a state where contacts c and a are connected, and in this state, when the control switch 28 is on, the compressor 33 is driven and the fan 25 is also driven, and the cold air from the cooler 24 is sent to the freezer compartment 22 and the refrigerator. It is supplied to the chamber 23 and a cooling operation is performed.

Heat sensitive part 28a of control switch 28
When the detected temperature becomes below +5 degrees, the control switch 28 is turned off as shown by the two-dot chain line in FIG. 1, and the heater 29 for guaranteeing the temperature inside the refrigerator is turned on. Then, since the resistance value of the heater 29 for guaranteeing the internal temperature is large, the compressor 33 becomes de-energized, and the fan 25 is also de-energized and the cooling operation is stopped. Then, when the temperature of the refrigerator compartment 23 gradually rises and the temperature sensed by the heat sensing section 28a reaches +8 degrees or higher, the control switch 28 is turned on and the cooling operation is started again. In this way, the temperatures of the freezer compartment 22 and the refrigerator compartment 23 are controlled (see area A in FIG. 3).

After this normal mode has been carried out for a certain period of time, when the movable contact of the changeover switch 32b in the defrosting timer 32 is switched to connect the contacts c and b (see the two-dot chain line), the compressor 33 is turned off, and the security heater 30 and the defrosting heater 26 are energized to perform the defrosting mode. Note that the defrosting mode is always started when the control switch 28 is turned on.

When this defrosting mode is started (see point B in FIG. 3), the cooler 24 is heated by the defrosting heater 26, thereby defrosting the cooler 24. Also, at this time, the security heater 30 is energized together with the defrosting heater 26, and the security heater 30 causes the control switch 2 to
Since the heat-sensitive portion 28a of 8 is heated, the control switch 28 is maintained in the on state and is prevented from being turned off.

When the temperature of the cooler 24 reaches the defrosting completion temperature, the bimetal 34 is turned off, the timer motor 32a is temporarily energized, and the changeover switch 32b is connected between contacts c and a. The cooling operation is switched to the normal mode (see point C in FIG. 3), and the cooling operation is performed again.

According to the first embodiment, the defrosting mode (
Contact point c- of the changeover switch 32b in the defrosting timer 32
When switched to the state (connected between
Since the control switch 28 is heated, the control switch 28 is reliably prevented from turning off. Therefore, since the control switch 28 can be prevented from turning off in the defrost mode, it is possible to reliably avoid the temporary interruption of defrosting as in the conventional case, and the problem of prolonging the defrosting time can be avoided. This is something that can definitely be prevented.

FIG. 4 shows a second embodiment of the present invention.
This embodiment differs from the first embodiment in the following points. That is, the AC power supply 36 is for 200V in this case. The first refrigerator temperature guarantee heater 37 and the security heater 38 are provided at the part that heats the heat sensitive part 28a of the control switch 28, and the second refrigerator temperature guarantee heater 39 is provided at the back of the refrigerator compartment 23. It is provided. These three heaters 37, 38,
39 are connected in series, one end of which is connected to the AC power supply 36.
is connected to one bus bar 36a, and the other end is connected to a common connection point between the a contact of the changeover switch 32b and the compressor 33. In addition, in order to lower the voltage applied to the defrosting heater 26, the diode 40 is connected to the bimetal 34.
Furthermore, a safety thermal fuse 41 is connected in series to the defrosting heater 26.

In the case of this second embodiment, in the normal mode, the changeover switch 3 in the defrosting timer 32 is
2b is in a state where contacts c and a are connected as shown by the solid line, and when the control switch 28 is on, the compressor 33 is driven and cooling operation is performed, and when the control switch 28 is off, the above three heater 37
, 38, 39 are energized, while the compressor 33
The power is cut off and the cooling operation is stopped. Then, the temperature of the refrigerator compartment 23 increases and each of the three heaters 37, 38, 3
The heat sensitive part 28 of the control switch 28 due to the heat generated by
a is heated, and the sensing temperature of the heat sensitive part 28a is +8
When the temperature exceeds the temperature, the control switch 28 is turned on and the cooling operation is started again. In this way,
The temperatures of the freezer compartment 22 and the refrigerator compartment 23 are controlled.

After such normal mode has been carried out for a certain period of time, when the movable contact of the changeover switch 32b in the defrosting timer 32 is switched to a state where the contacts c and b are connected (see the two-dot chain line), the defrosting is started. The heater 26 is energized and the defrosting mode is performed.

At this time, since the first and second chamber temperature guarantee heaters 37, 39 and the guarantee heater 38 are energized via the compressor 33, each of these three heaters 37, 38, 39 control switch 28
By heating the heat-sensitive portion 28a of the control switch 28, the control switch 28 is maintained in the on state and is prevented from being turned off. Therefore, in this second embodiment as well, the control switch 28 is never turned off in the defrosting mode, and good defrosting is always performed.

When the temperature of the cooler 24 reaches the defrosting completion temperature, the bimetal 34 is turned off as in the first embodiment, and accordingly, the timer motor 32a is temporarily energized and the changeover switch 32b is turned off. The mode is switched to the normal mode in which the contacts c and a are connected, and the cooling operation is performed again.

[0034] In the second embodiment as well, the same effects as in the first embodiment can be obtained. In this second embodiment, the first refrigerator temperature guaranteeing heater 37
and the security heater 38 may be composed of one heater.

[0035]

[Effects of the Invention] As is clear from the above description, according to the present invention, the heat-sensitive portion of the control switch is heated by the security heater when the defrosting heater is energized, so that the defrosting mode is not started. It is possible to prevent the control switch from being turned off in a state where the defrosting process is in a state where the defrosting process is in progress, thereby preventing the time from the start to the end of defrosting from becoming long, and thereby achieving the excellent effect that defrosting can always be performed satisfactorily.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram showing a first embodiment of the present invention.

[Figure 2]
Vertical side view of refrigerator

[Figure 3] Diagram showing temperature changes of control switch and cooler

FIG. 4 is an electric circuit diagram showing a second embodiment of the present invention.

[Figure 5]
A diagram equivalent to Figure 2 showing a conventional example

[Figure 6] Diagram equivalent to Figure 1

[Figure 7] Diagram equivalent to Figure 3

[Explanation of symbols]

21 is the refrigerator body, 23 is the refrigerator compartment, 24 is the cooler, 26
is a defrosting heater, 28 is a control switch, 28a is a heat sensitive part, 30 is a security heater, 33 is a compressor, 3
5 is a defrosting circuit, and 38 is a security heater.

Claims (1)

[Claims] Claim 1: A control switch that turns on and off based on the temperature sensed by a heat-sensing section installed in a refrigerator compartment, and controls the power supply to and disconnection of a compressor; a defrosting heater provided to perform the
In a refrigerator equipped with a defrosting circuit that forms an energizing path for the defrosting heater based on predetermined conditions, when the defrosting circuit forms an energizing path for the defrosting heater, it becomes energized and the control switch becomes thermally sensitive. A refrigerator characterized by being provided with a security heater that heats a portion of the refrigerator.