JP2005351545A - Freezing refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively prevent the event that a temperature in a freezing chamber carelessly rises in the state that an installation atmospheric temperature lowers, while offering construction for executing the operation control of a refrigerating cycle compressor in accordance with the output of a refrigerating chamber temperature sensor. <P>SOLUTION: A control circuit 7 executes sensor control, namely, the operation control of the compressor 8 in accordance with the output of the refrigerating chamber temperature sensor 1 in the state that a temperature detected by an outside air temperature sensor 3 exceeds a preset lower limit temperature. The control circuit 7 executes time control, namely, the energization/deenergization of the compressor 8 in preset static cycles, instead of the sensor control, in the state that the temperature detected by the outside air temperature 3 does not exceed the lower limit temperature. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a refrigerator provided with a freezing room and a refrigerating room in different temperature zones, and more particularly to a refrigerating refrigerator configured to execute operation control of a refrigerating cycle compressor based on an output of a refrigerating room temperature sensor.

In a refrigerator / freezer provided with a freezer compartment and a refrigerator compartment, particularly in a refrigerator refrigerator configured to control the operation of a compressor for a refrigeration cycle based on the output of a temperature sensor arranged to detect the temperature in the refrigerator compartment When the temperature in the refrigeration room is difficult to rise at a low outside air temperature such as in winter, the operation rate of the compressor may be reduced, and the temperature in the freezer compartment may be inadvertently raised. Conventionally, in order to cope with such a situation, a temperature compensation heater for heating the freezer temperature sensor is provided, and the heater is energized when the compressor is turned off to forcibly increase the temperature detected by the temperature sensor. A configuration is performed (for example, see Patent Document 1).
JP 7-98170 A

When the temperature of the refrigerator / freezer installation atmosphere is low (for example, 5 ° C. or lower), even if the temperature compensation heater generates heat, the rate of increase in the temperature detected by the temperature sensor for the refrigerator compartment becomes slow. It may take a long time to restart, and during that time the temperature in the freezer compartment may become higher than the limit.
The present invention has been made in view of the above circumstances, and the purpose thereof is a state in which the operation atmosphere of the compressor for the refrigeration cycle is executed based on the output of the temperature sensor for the refrigerating room, but the installation atmosphere temperature is lowered. The present invention relates to a refrigerator-freezer that can effectively prevent a situation in which the temperature in the freezer compartment rises carelessly.

  In order to achieve the above object, the invention according to claim 1 includes a freezing room and a refrigerating room, and is provided with a control means for performing operation control of the refrigerating cycle compressor based on the output of the refrigerating room temperature sensor. In the refrigerator, after providing an outside air temperature sensor for detecting the temperature of the installation atmosphere of the refrigerator, the control means is used for the refrigerator compartment when the temperature detected by the outside air temperature sensor is equal to or lower than a preset lower limit temperature. The operation control of the compressor based on the output of the temperature sensor is stopped, and the time control is performed in which the compressor for the refrigeration cycle is cut off at a preset fixed cycle.

  According to the first aspect of the present invention, when the temperature detected by the outside air temperature sensor, that is, the temperature of the installation atmosphere of the refrigerator-freezer is equal to or lower than a preset lower limit temperature, the compressor based on the output of the temperature sensor for the refrigerator compartment The operation control is stopped, and time control is performed such that the refrigeration cycle compressor is turned off and on at a preset fixed cycle. As a result, when the temperature of the installation atmosphere of the refrigerator / refrigerator becomes lower than the lower limit temperature, the compressor is forced to operate at a predetermined cycle. There is no fear of it.

(First embodiment)
A first embodiment of the present invention will be described below with reference to FIGS.
In FIG. 1, the basic part of the electrical configuration of the refrigerator-freezer is schematically shown by a combination of functional blocks. Although not shown, the refrigerator-freezer targeted by the present embodiment includes a freezer compartment and a refrigerator compartment divided into upper and lower portions by a heat insulating partition wall. For example, a refrigerator cover is provided on the back of the freezer compartment. The cooler is arranged in the cooling chamber formed in this manner, and the cool air generated by the cooler is supplied to the freezer compartment and the refrigerator compartment according to the drive of the fan device (which will be described later). .

In FIG. 1, a temperature sensor 1 for a refrigerator compartment is constituted by a temperature sensitive resistance element such as a thermistor, and the temperature sensor circuit 2 to which the temperature sensor 1 is connected responds to the temperature in the refrigerator compartment. A voltage level temperature detection signal Sr is output.
The outside air temperature sensor 3 arranged so as to detect the temperature of the installation atmosphere of the refrigerator / freezer is also composed of a temperature sensitive resistance element such as a thermistor, and from the room temperature detecting circuit 4 to which the outside air temperature sensor 3 is connected. A temperature detection signal Sa having a voltage level corresponding to the temperature of the installation atmosphere of the refrigerator-freezer (hereinafter referred to as ambient temperature) is output.

The cooler temperature sensor 5 is also composed of a temperature sensitive resistance element such as a thermistor, and a temperature detection signal at a voltage level corresponding to the cooler temperature is sent from the cooler temperature detection circuit 6 to which the temperature sensor 5 is connected. Se is output.
The control circuit 7 (corresponding to the control means) to which the temperature detection signals Sr, Sa, Se are input is mainly composed of a microcomputer. These temperature detection signals Sr, Sa, Se and a preset program are provided. On the basis of the above, the power cut-off control of the load group such as the compressor 8, the fan device 9, the temperature compensation heater 10 and the defrost heater 11 is executed. The loads are controlled through the drive circuits 8a to 11a corresponding to the loads.

  The compressor 8 is for driving a refrigeration cycle, and in its operating state, liquefied refrigerant is supplied to the cooler through a condenser or the like. The fan device 9 is for supplying the cool air generated by the cooler into the cabinet, and in the operating state, the cool air from the cooler is supplied into the freezer compartment, and then the freezer and refrigerator compartments. It is configured to be supplied into the refrigerating chamber through a cold air passage formed in the heat insulating partition wall therebetween, and then returned to the cooling chamber in which the cooler is disposed. The cold air passage is provided with an air volume adjusting mechanism capable of adjusting the amount of cool air blown from the freezer compartment side to the refrigerator compartment according to the operation of the operation knob. The interior temperature can be controlled by adjusting the air volume.

  The temperature compensation heater 10 is for heating the cold room temperature sensor 1 in response to the energization, and is basically energized when the compressor 8 is stopped. Further, the defrost heater 11 is for melting the frost formation of the cooler in response to the energization. The defrost heater 11 is energized at a predetermined timing (for example, every time a certain time elapses), and the temperature detection signal The power is cut off when the cooler temperature indicated by Se is equal to or higher than a predetermined temperature.

FIG. 2 shows a portion related to the gist of the present invention in the contents of control by the control circuit 7, which will be described below.
In FIG. 2, in the power-on state, it is determined whether or not the ambient temperature indicated by the temperature detection signal Sa is equal to or lower than a preset lower limit temperature RT (for example, 10 ° C.) (step A1), and “NO” is determined. During the period, that is, the period when the ambient temperature exceeds the lower limit temperature RT, the sensor control routine A2 is executed. In the sensor control routine A2, although not specifically illustrated, the operation control of the compressor 8 is executed based on the temperature detection signal Sr (that is, the output of the temperature sensor 1 for the refrigerator compartment).

  On the other hand, when the ambient temperature becomes equal to or lower than the lower limit temperature RT (“YES” in step A1), a time control routine A3 including steps B1 to B9 is executed instead of the sensor control routine. That is, in the time control routine A3, first, it is determined whether or not the compressor 8 is operating (step B1). If the compressor 8 is operating, the operating time of the compressor 8 is measured (step B2). Thereafter, the process waits until the measurement time reaches a predetermined on time Ton or until the ambient temperature indicated by the temperature detection signal Sa exceeds the lower limit temperature RT (10 ° C.) (step B3). , B4).

  When the ambient temperature exceeds the lower limit temperature RT (“YES” in step B4), the process proceeds to the sensor control routine A2, and the measurement time (that is, the operation continuation time of the compressor 8) has reached the on time Ton. When ("YES" in step B3), after executing step B5 for stopping the operation of the compressor 8, the stop time of the compressor 8 is measured (step B6). Thereafter, the process waits until the measurement time reaches a predetermined off time Toff or until the ambient temperature indicated by the temperature detection signal Sa exceeds the lower limit temperature RT (steps B7 and B8).

When the ambient temperature exceeds the lower limit temperature RT (“YES” in step B8), the process proceeds to the sensor control routine A2), and the measurement time (that is, the operation stop time of the compressor 8) reaches the on time Toff. When this occurs ("YES" in step B7), after executing step B9 for starting the operation of the compressor 8, the process returns to step B2.
In short, in the time control routine A3, control is performed so that the power interruption of the compressor has a preset fixed cycle, and when the ambient temperature exceeds the lower limit temperature RT during the control, the time The control is terminated and the state returns to the normal sensor control state (a state in which the operation of the compressor 8 is controlled based on the output of the temperature sensor 1 for the refrigerator compartment).

  Here, FIG. 3 shows an example of the change characteristics of the temperature in the freezer compartment when the sensor control is performed under the condition that the ambient temperature (temperature of the installation atmosphere of the refrigerator / freezer) is equal to or lower than the lower limit temperature RT. Examples of change characteristics of the temperature in the freezer compartment in a state where time control as described in the embodiment is performed are shown. However, in FIG. 3, the overshoot and undershoot of the freezer compartment temperature that occur when the operation of the compressor 8 is started and stopped are shown in a neglected state.

  As shown in FIG. 3, when the sensor control is performed in a state where the ambient temperature is equal to or lower than the lower limit temperature RT (the temperature of the installation atmosphere of the refrigerator / freezer is low), the temperature compensation heater 10 generates heat. Even in such a case, the rate of increase in the temperature detected by the temperature sensor 1 for the refrigerating room is slowed down, so that the operation stop time of the compressor 8 is prolonged, and during that time, the temperature in the freezer compartment rises to a relatively high temperature. On the other hand, in this embodiment, when the ambient temperature becomes equal to or lower than the lower limit temperature RT (10 ° C.), time control is executed instead of the sensor control. During this time control, the compressor 8 The operation is forcibly performed at a predetermined cycle (operation time Ton, stop time Toff). In this case, the temperature in the freezer compartment can be adjusted by setting the on-time Ton and the off-time Toff, respectively. In the case where the freezer compartment temperature is set as in the example of FIG. Therefore, there is no possibility that the temperature of the refrigerator compartment becomes higher than the limit.

(Second Embodiment)
In the first embodiment, the temperature compensation heater 10 has been described on the premise that the temperature compensation heater 10 is energized when the operation of the compressor 8 is stopped. However, such energization control for the temperature compensation heater 10 is performed only when the sensor control is performed. It is good also as a structure which prohibits the electricity supply control with respect to the temperature compensation heater 10 at the time of execution of time control. For example, as shown in FIG. 4 showing the second embodiment of the present invention, when the process proceeds to the time control routine A3, the step B0 for prohibiting the energization of the temperature compensation heater 10 is executed before the execution of the step B1, When returning to the sensor control routine A2, the process may return to the sensor control routine A2 after executing Step B10 for canceling the prohibition of energization of the temperature compensation heater 10.

  According to this embodiment having such a configuration, the temperature compensation heater 10 is not energized unnecessarily during the time control period, which is beneficial for power saving. .

(Third embodiment)
FIG. 5 shows a third embodiment of the present invention. Hereinafter, only portions different from those of the first embodiment will be described.
That is, the processing routine shown in FIG. 5 shows the content of the energization control for the temperature compensation heater 10 among the control content by the control circuit 7, for example, the operation stop of the compressor 8 in a state where the sensor control is being performed. Executed in the period. Specifically, it is determined which of the three stages of the ambient temperature indicated by the temperature detection signal Sa is less than 25 ° C., 25 ° C. or more and less than 35 ° C., or 35 ° C. or more (steps C1 to C3). If the ambient temperature is 10 ° C. or lower, the time control is performed and the sensor control is not performed. Therefore, the state determined as “YES” in step C1 is actually 10 Corresponds to the state of ° C <ambient temperature <25 ° C.

When the ambient temperature is less than 25 ° C., the temperature compensation heater 10 is energized with a duty ratio of 100%. When the ambient temperature is 25 ° C. or more and less than 35 ° C., the temperature compensation heater 10 is energized with a duty ratio of 70%. In the above case, the temperature compensation heater 10 is energized with a duty ratio of 50% (steps C3 to C5).
According to this embodiment configured as described above, the temperature compensation heater 10 heats the temperature sensor 1 for the refrigerator compartment with the optimum heat amount corresponding to the ambient temperature during the period in which the operation of the compressor 8 is stopped in the sensor control state. Will be able to.

(Other embodiments)
The present invention is not limited to the embodiments described above and shown in the drawings. For example, the following modifications or expansions are possible.
In a state where the temperature detected by the outside air temperature sensor 3 (ambient temperature) is −10 ° C. or lower, the execution of the time control can be stopped. That is, when the ambient temperature is −10 ° C., even when the freezer temperature is increased to the maximum, it can be maintained at −10 ° C., and there is no fear that frozen foods such as ice cream in the freezer will melt. Therefore, according to the configuration as described above, it is possible to prevent a situation in which time control is performed unnecessarily.

  Although the example has been described in which the lower limit temperature RT is 10 ° C., the lower limit temperature RT may be other values such as 5 ° C., for example.

Functional block diagram showing the electrical configuration of the refrigerator-freezer according to the first embodiment of the present invention. Flow chart showing contents of control by control circuit Refrigeration room temperature characteristics diagram for action explanation FIG. 2 equivalent diagram showing a second embodiment of the present invention. FIG. 2 equivalent view showing a third embodiment of the present invention.

Explanation of symbols

  1 is a temperature sensor for a refrigerator compartment, 2 is an internal temperature detection circuit, 3 is an outside air temperature sensor, 4 is a room temperature detection circuit, 7 is a control circuit (control means), 8 is a compressor, and 10 is a temperature compensation heater.

Claims (4)

In a refrigerator-freezer comprising a freezer compartment and a refrigerator compartment, and provided with a control means for executing operation control of the compressor for the refrigerant cycle based on the output of the temperature sensor for the refrigerator compartment,
An outside air temperature sensor that detects the temperature of the installation atmosphere of the refrigerator is provided.
When the temperature detected by the outside air temperature sensor is equal to or lower than a preset lower limit temperature, the control means replaces the operation control of the compressor based on the output of the temperature sensor for the refrigerator compartment, A refrigerator-freezer characterized in that the compressor is configured to execute time control in which the compressor is turned off and on at a fixed cycle set in advance. A temperature compensation heater is provided that is energized when the compressor is stopped to heat the temperature sensor for the refrigerator compartment,
2. The refrigerator-freezer according to claim 1, wherein when the time control is executed, the control unit performs control to prohibit energization of the temperature compensation heater. A temperature compensation heater is provided that is energized when the compressor is stopped to heat the temperature sensor for the refrigerator compartment,
3. The control unit according to claim 1, wherein energization control of the temperature compensation heater is performed by time-sharing control such that the duty ratio becomes higher as the temperature detected by the outside air temperature sensor is lower. Freezer refrigerator. 4. The refrigerator-freezer according to claim 1, wherein the control unit stops the execution of the time control when the temperature detected by the outside air temperature sensor is −10 ° C. or lower. 5.

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