JP7305519B2 - refrigerator - Google Patents

Description

The present invention relates to refrigerators.

According to Patent Document 1, if a machine room fan (C fan) 20 stops abnormally, the controller 21 repeats the restart of the C fan 20 up to a preset number of times N (for example, 3 times). It is disclosed that the C fan 20 is determined not to be out of order and returns to normal operation (0025). Also, if the restart fails, the compressor may be stopped (0027).

JP 2009-264660 A

When it is detected that the machine room fan has stopped abnormally, the machine room fan is not actually running, or the path that sends the feedback signal of the machine room fan to the microcomputer is broken. It is conceivable that it may be judged that In the latter case, the machine room fan itself can be driven, so there is relatively little need to stop the compressor immediately. If the compressor stops, the cooling inside the refrigerator stops, which is a big disadvantage for the user.

The refrigerator of the present invention made in view of the above circumstances,
a compressor;
a compressor temperature sensor arranged near the compressor;
a non-insulated power board for the compressor;
a substrate temperature sensor arranged near the power substrate;
a machine room housing the compressor and a machine room fan acting on fluid around the power board;
If the compressor temperature sensor is high temperature, stop the compressor ,
If the compressor temperature sensor is not at a high temperature, the machine room fan is abnormal and the substrate temperature sensor is at a high temperature, stopping the compressor;
On the other hand, if the compressor temperature sensor is not at a high temperature, the machine room fan is abnormal and the substrate temperature sensor is not at a high temperature, the number of revolutions of the compressor is limited to be low,
The compressor is driven when the temperature of the compressor temperature sensor is not high and the machine room fan is normal.

Front view of the refrigerator of the embodiment Longitudinal sectional view of the refrigerator of the embodiment A circuit block diagram of a power board and a control board of the refrigerator of the embodiment Schematic front view of the control board of the embodiment The top view of the machine room of embodiment Control flowchart of the compressor of the embodiment Threshold setting diagram for high temperature determination of the compressor and power board of the embodiment

[Refrigerator 1]
FIG. 1 is a front view of a refrigerator 1 of this embodiment. A refrigerator 1 has a refrigerator compartment 2, an ice making compartment 3, an upper freezer compartment 4, a lower freezer compartment 5, and a vegetable compartment 6 as storage compartments in this order from above. A refrigerating-chamber left door 8 and a refrigerating-chamber right door 9 for opening and closing the refrigerating chamber 2 are attached to the front of the refrigerating chamber 2, and are fixed by an upper hinge 10 and a lower hinge 11, respectively. The front openings of the ice making compartment 3, the freezer compartments 4 and 5, and the vegetable compartment 6 are each opened and closed by a drawer type door. A known door sensor is arranged in the vicinity of each door, and can detect opening and closing of each door.

FIG. 2 is a longitudinal sectional view showing the internal configuration of the refrigerator 1. As shown in FIG. The refrigerator 1 generates cool air by a refrigerating cycle including a cooler 13 and a compressor 14, and circulates the cool air by one or more fans including a freezer compartment fan 15 to circulate each storage compartment 2-6 of the refrigerator 1. Cool to the specified temperature zone. A power board 17 controls the compressor 14 and the like, and a control board 26 controls the fan and the like. Each storage compartment is insulated from the outside air by a heat insulating material 52 between an outer box 50 facing the outside air and an inner box 51 facing inside the storage compartment.

The refrigerator compartment 2 is provided with a refrigerator compartment temperature sensor 29, an internal light LED 31, a shelf, and a rear panel 53 arranged behind the shelf. is provided.

The cooler 13 is located behind any one of the freezer compartments 3, 4, and 5, and a defrosting heater 22 is provided below the cooler 13. As shown in FIG. The refrigerator 1 includes other heaters such as a refrigerating compartment bottom heater 23 and a vegetable compartment heater 25 arranged on the walls of the refrigerator compartment 2 and the vegetable compartment 6 to suppress condensation, It may also have a rotary partition heater 24 provided in the known rotary partition that contributes to thermal insulation between the chamber doors 8,9.

[Overview of power board 17 (non-insulated board)]
The power board 17 is a board having at least a part of a non-insulated area with respect to the commercial power supply, and is a board having circuits for driving high-voltage loads such as the compressor 14 and the heaters 22 to 25. . The power board 17 is provided on the rear side (rear side) of the refrigerator 1 and is accommodated in the machine room 16 in which the compressor 14 is accommodated. The machine room 16 is also provided with a machine room fan 19 for cooling the reactor 18 and the members inside the machine room 16 such as the compressor 14 . The power board 17 is electrically connected to a commercial power source via a power plug 20 . Note that the machine room 16 may be located on the upper rear side or the lower rear side of the refrigerator 1 . A detachable machine room cover 161 is arranged in the machine room 16 in a range including at least the rear side.

[Overview of control board 26 (insulating board)]
The control board 26 is a board that is insulated from the commercial power supply even when the power plug 20 is electrically connected to the commercial power supply, and has a circuit that drives low-voltage loads (for example, DC 12V) such as fans and lighting. It is a substrate with A control board 26 is arranged in one of the storage chambers. For example, the control board 26 is arranged in the refrigerator compartment 2, which is the storage compartment furthest from the machine room 16 (power board 17). Since there is little need for the user to operate the control board 26, it is preferably provided behind the back panel 53 on the back side of the storage compartment.

The control system load wiring 30 (dotted line in FIG. 2), which is the output wiring of the control board 26, includes the freezer compartment fan 15 and the machine room fan 19 as an example of fans, the interior light LED 31 as an example of lighting, and the cool air path. It is connected to the motor of the damper used for opening and closing the valve.

The control board 26 is provided with input circuits for sensors and switches, including a refrigerator compartment temperature sensor 29 and a freezer compartment temperature sensor 28 as examples of sensors, and a refrigerator compartment door as an example of a sensor or switch for detecting door opening/closing. A switch 7 and the like are connected. Input wiring is not shown.

[Circuit Blocks of Substrates 17 and 26]
FIG. 3 is a circuit block diagram showing the electrical system of the refrigerator 1. As shown in FIG.
The power board 17 and the control board 26 have portions that are communicatively and electrically connected, and can transmit and receive information and power. For example, the control board 26 and the power board 17 are communicatively connected by inter-microcomputer communication and control power wiring 27 (one-dot chain line in FIG. 2). Specifically, the heater microcomputer 41 of the power board 17 and the internal control microcomputer 39 of the control board 26 are connected in a communicative manner, and serial communication, for example, can be performed as inter-microcomputer communication. As a result, if the number of heaters is two or more (four in this embodiment), the internal control microcomputer 39 can control each heater via the heater microcomputer 41 with a smaller number of communication lines (for example, one) than the number of heaters. can exercise control.

In addition, the low voltage side generated by the switching power supply circuit 36 of the power board 17 and the DC/DC conversion circuit 38 of the control board 26 are electrically connected, and the 12 V (control system voltage) generated by the switching power supply circuit 36 is electrically connected. ) is supplied to the DC/DC conversion circuit 38 .

In addition, the compressor control microcomputer 35 of the power board 17 and the internal control microcomputer 39 of the control board 26 are communicatively connected.

[Circuit of Power Board 17]
The power board 17 that receives power from the commercial power supply includes a switching power supply circuit 36 that generates a low-voltage DC power supply based on a high-voltage DC voltage, an inverter module 34 that supplies voltage to the motor of the compressor 14, and a compressor microcomputer that controls the inverter module 34. 35. It has a heater microcomputer 41 that controls a plurality of heaters. Moreover, the power board 17 preferably has a noise filter circuit 32 for reducing noise of the commercial power supply and a reactor 18 for suppressing harmonic current.

(Generation of DC voltage from commercial power supply)
The commercial power supplied to the refrigerator 1 through the power plug 20 preferably first passes through the noise filter circuit 32 and the reactor 18 to become a shaped AC voltage. This AC voltage is supplied to the converter circuit 33 and converted into a high-voltage DC voltage (for example, DC280V).

(Compressor 14 drive based on high voltage DC voltage)
A portion of the high voltage DC (eg, 280V DC) is supplied to the inverter module 34 .

The inverter module 34 converts a high DC voltage into an AC voltage according to a control signal from the compressor microcomputer 35 and outputs the AC voltage to the motor of the compressor 14 . As a result, the compressor 14 is variable speed controlled.

(Generation of low-voltage power supply)
A part of the high-voltage DC voltage (for example, 280 V DC) is supplied to the switching power supply circuit 36 . The switching power supply circuit 36 down-converts the high DC voltage from the converter circuit 33 to a low power supply voltage using a switching transformer. The power source for step-down conversion by the switching power supply circuit 36 includes P15V (power system) used as the power source for the control circuit inside the inverter module 34, and P3.3V used as the power source for the compressor control microcomputer 35 and its peripheral circuits. (power system). These are non-insulated power sources because the inverter module 34 and the compressor control microcomputer 35 are electrically connected to the commercial power source. The reference potential (P0V) of P15V (power system) and P3.3V (power system) is the same as the reference potential of the DC voltage from the converter circuit 33 to control the inverter module 34, and is not isolated from the commercial power supply. configuration.

In addition to the power source that is step-down converted by the switching power source circuit 36, there is 12V (control system) that is supplied to the control board 36 via the control power source wiring. The 12V (control system) is insulated from the commercial power supply by a switching transformer. 12V (control system) is electrically connected to the control board 26 via control power wiring.
In FIG. 3, the primary side (non-insulated) area is a circuit configuration that is not insulated from the commercial power supply (power plug 20), and the secondary side (insulated) area is a circuit configuration that is insulated from the commercial power supply. .

(heater drive)
The power board 17 further includes a heater driving circuit 40 having a switch for turning ON/OFF the power supply to each heater 22-25, and a switch for the heater driving circuit 40 (for example, an insulating element such as a photocoupler or SSR can be used). and a heater microcomputer 41 that controls the . The heater drive circuit 40 is preferably supplied with high voltage power that has passed through the noise filter circuit 32 . The heater microcomputer 41 outputs ON-OFF commands for each switch via, for example, a photocoupler. This command is input to the heater microcomputer 41 via the communication line from the interior control microcomputer 39, which will be described later.

A heater load wiring 21 (broken line in FIG. 2) is wired from the power board 17 to each heater load 22-25. Heater loads include a defrosting heater 22 for removing frost on the cooler 13, a refrigerating compartment bottom heater 23 for adjusting the temperature of the lower part of the refrigerating compartment, and a heater for preventing cold air leakage between double doors. A rotary shed heater 24 for preventing condensation on the rotary shed, a vegetable compartment heater 25 for adjusting the temperature of the vegetable compartment 6, and the like are provided.

(Reading of operation information data (control log) from machine room 19 side)
The operation information data (operation log) at each time such as the detection values of various sensors of the refrigerator 1, the rotation speed of the compressor, the ON-OFF state of the heater, etc. is stored in the memory of the refrigerator 1, and the operation information data is used to operate the factory. It may be inspected before shipment or used for maintenance after installation in a home or the like. In order to connect the memory to another device via a wired connection, it is necessary to establish a wired connection with a readout connector or the like of the board on which the memory is arranged.

The heater microcomputer 41 is connected to a memory 421 arranged on the power board 17, and stores operation information data such as temperature sensor values received from the internal control microcomputer 39 in the memory 421 for a certain period of time. The power board 17 is provided with a readout connector 431 for accessing the memory 421 . Readout connector 431 is insulated from the commercial power supply.

The memory 421 outputs data to other equipment such as a personal computer through a readout connector 431 . During a commercial test before shipment from the factory, the operation information data can be used to check the operation, and it can be used for analysis when a problem occurs. Being able to access driving information data is highly convenient.

The heater microcomputer 41, memory 421, and readout connector 431 are powered by a 5V (control system) power supply insulated from the commercial power supply in order to prevent electric shock to workers using the readout connector 431 and to prevent failures due to ground faults in other devices such as personal computers. It is configured to work. The same applies to a readout connector 43, which will be described later. A memory 42 and a readout connector 43 are also provided on the control board 26 side. 1 tends to be more complicated than the access from the machine room 19.

Therefore, in the present embodiment, since the readout connector 431 is also provided on the power board 17 side, it is possible to access through the machine room 16 even in the refrigerator 1 in which the control board 26 is difficult to access after the assembly is completed. Since the memory 421 is normally used for testing before shipping, it does not require a large storage capacity and can be made smaller than the memory 42 .

Note that the memory 421 does not necessarily have to be connected to the heater microcomputer 41 , and can be connected to another microcomputer that is electrically insulated from the power plug 20 .

[Circuit of control board 26]
The control board 26 has an interior control microcomputer 39 that acquires detection values of sensors and door switches, and user operation data through the operation board, and controls each fan, lighting, damper, etc. based on the sensing information. The internal control microcomputer 39 is preferably grounded.

(Generation of power supply used to drive sensors, etc.)
The control board 26 uses the 12V (control system) power supply (first DC voltage) supplied from the power board 17 to generate a 5V (control system) power supply (second DC voltage) used to drive the sensor. . Therefore, the control board 26 has a DC/DC conversion circuit 38 for further stepping down the 12V (control system) power supply. DC/DC conversion circuit 38 is preferably grounded.

5V (control system) is used as a power supply for elements such as the internal control microcomputer 39, sensors, door switches, internal control microcomputer 39, etc., which transmit and receive low-voltage detection signals and control signals. In particular, when noise is superimposed on the power supply of the sensor, the detection accuracy of the sensor is lowered. For example, when noise is superimposed on the detection signal of a temperature sensor that detects temperature using an analog voltage, the temperature is erroneously detected. In this embodiment, by generating 5V (control system) on the side of the control board 26, the inverter module 34, the compressor control microcomputer 35, and the switching power supply circuit 36, which are high voltage and have relatively large noise, can be remotely powered. can generate Therefore, it is possible to suppress deterioration in detection accuracy of the sensor.

To elaborate on this point, the DC/DC conversion circuit 38 uses a DC/DC converter, an IC that adjusts the output voltage by high-frequency switching operation, in order to improve efficiency. Since the DC/DC converter adjusts the switching period while monitoring the output voltage, there is concern about the influence of external noise. By mounting the DC/DC conversion circuit 38 on the control board 26 side, it is kept away from the inverter module 34 and the switching power supply circuit 36, which generate large noise, and the influence of external noise can be reduced.

In addition, the DC/DC conversion circuit 38 generally uses an IC for performing the above-described high-frequency switching operation and a coil for storing electric power energy as constituent elements, and the high-frequency waves radiated from them are often used. Noise and leakage magnetic flux may be superimposed on peripheral parts and wiring, causing malfunction.
FIG. 4 is a schematic front view of the control board 26 of this embodiment. A DC/DC conversion circuit 38 is arranged on the board edge side of the control board 26 . Also, the wiring 80 connected to the control board 26 does not pass vertically above the DC/DC conversion circuit 38 . Also, a ground pattern 82 for the control system power supply is provided between the DC/DC conversion circuit 38 and the connector 81 and preferably surrounds it. As a result, a configuration in which noise is less likely to be superimposed on other control elements and other wiring patterns on the control board 26 can be achieved.

The freezer compartment fan 15, the machine room fan 19, the interior light LED 31, and the like are driven using 12V (control system) supplied from the power board 17. FIG. The refrigerator internal control microcomputer 39 has a 12V system load driving circuit 37 for driving these 12V system loads.

(Reading of operation information data (control log) from storage room side)
The control board 26 has a memory 42 for storing sensor detection values acquired by the internal control microcomputer 39, a log of the driving state of each fan, lighting, and the compressor 14, and a readout connector 43 for freely accessing the memory 42. . After the refrigerator is installed in a home or the like, access from the readout connector 431 of the power board 17 is usually difficult because the machine room 19 is in contact with the wall surface. Therefore, a memory 42 and a readout connector 43 are also provided on the control board 26 side in order to improve accessibility during maintenance after installation.

In this embodiment, readout connectors are provided in the machine room 19 accessible from the back side of the refrigerator 1 and in the storage room accessible from the front side. In view of the difficulty of access, the readout connector may be provided on the side rather than within the storage compartment to facilitate access from the front. For example, a control board and a readout connector may be provided on the side wall within the reservoir.

(Drive command for heaters 22-25)
The internal control microcomputer 39 determines the energization rate of each heater 22 to 25 using the detection value of each sensor (temperature sensor and humidity sensor), and sends the energization rate of each heater to the heater microcomputer 41 communicatively connected. to send. The heater microcomputer 41 drives the heater driving circuit 40 as instructed by the internal control microcomputer 39 . The heater driving circuit 40 receives the duty ratio command and switches the energization state of each heater to the commercial power supply.

A heater microcomputer 41 is provided on the power board 17 for the purpose of reducing the number of wirings between the two boards, and commands for the heater microcomputer 41 are issued from the internal control microcomputer 39 . Therefore, communication between the heater microcomputer 41 and the internal control microcomputer 39 may become impossible for some reason, such as disconnection of the communication line. In this embodiment, when the heater microcomputer 41 detects communication interruption with the internal control microcomputer 39, in principle, the operation of the heater is stopped or the duty ratio is lowered in order to prevent an excessive temperature rise of the heater. However, for heaters that tend to generate dew, such as the rotary partition heater 24, the duty ratio is maintained at a predetermined value or higher, for example, 50% or higher.

[Machine room layout]
FIG. 5 is a top view of the inside of the machine room 16 of this embodiment.
In the machine room 16, a compressor 14 uninsulated from the commercial power supply 1, a machine room fan 19 insulated from the commercial power supply 1 and controlled by the internal control microcomputer 39 of the control board 26, A compressor temperature sensor 91 arranged to detect temperature information of the compressor 14, a power board 17, and a board temperature sensor 92 arranged near the power board 17 are provided. The compressor 14 is arranged on one side of the machine room fan 19, and the power board 17 is arranged on the other side. As shown in FIG. 3, the machine room fan 19 is driven by power supply from the 12V load drive circuit 37 to generate an air flow around the compressor 14, the power board 17, and the surroundings thereof for air cooling.

[Control when the machine room fan 19 is abnormal]
The control board 26 includes a 12V load drive circuit 93 for outputting a signal from the refrigerator control microcomputer 39 to the 12V load drive circuit 37, and a 12V load drive wiring 95 for outputting a signal from the 12V load drive circuit 37 to the 12V load. , a 12V system load drive wiring 96 and a 12V system load drive circuit 94 for feeding back the drive state of the machine room fan 19 (rpm pulse, current, hall sensor information, etc.).

When the internal control microcomputer 39 cannot detect the feedback signal from the machine room fan 19, for example, when the number of revolutions is 0 and the current is 0, it is determined that the machine room fan 19 is abnormal. For example, the board circuit patterns such as the circuits 37, 93, and 94 or the wiring 95 and 96 are disconnected, and the machine room fan 19 is normally driven, but the feedback is not obtained. , the machine room fan 19 may actually be out of order and cannot be driven. In the former case, since the compressor 14 and the power board 17 are cooled, there is no problem even if the compressor 14 is continued to be driven. In the latter case, since the compressor 14 and the power board 17 are not cooled, the temperature conditions of the compressor 14 and the power board 17 are observed and the rotational speed of the compressor 14 is regulated or stopped as appropriate. The power board 17 and the reactor 18 and the inverter module 34 provided in the vicinity thereof change the amount of heat generated according to the rotation speed of the compressor 14. Therefore, when the power board 17 overheats, the rotation speed of the compressor 14 is preferably suppressed.

The abnormality determination result of the machine room fan 19 is used in step S101 of the control flow to be described later. It should be noted that, rather than judging that there is an abnormality at the moment when the feedback is no longer obtained, it may be judged when the feedback is not obtained continuously for a predetermined number of times.

FIG. 6 is a flow chart of the rotation speed control of the compressor 14. As shown in FIG. When the compressor temperature sensor 91 is high temperature (step S100, Yes), the compressor 14 is stopped (step S105). When the temperature of the compressor temperature sensor 91 is not high (step S100, No), the machine room fan 19 is abnormal (step S101, Yes), and when the temperature of the substrate temperature sensor 92 is high (step S102, Yes), the compressor 14 is stopped (step S105). On the other hand, when the temperature of the compressor temperature sensor 91 is not high (step S100, No), the machine room fan 19 is abnormal (step S101, Yes), and when the temperature of the substrate temperature sensor 92 is not high (step S102, No), the compression The number of revolutions of the machine 14 is restricted to be low (steps S103, S106). When the temperature of the compressor temperature sensor 91 is not high (step S100, No), and when the machine room fan 19 is not abnormal (step S101, No), it can be determined that there is no problem in driving the compressor 14. (steps S104, S106).

FIG. 7 is a setting diagram of threshold values for judging the high temperature of the compressor 14 and the power board 17. FIG. A hysteresis region (dead band region) may be provided for determining whether the compressor temperature sensor 91 or the substrate temperature sensor 92 is at a high temperature or not. The hysteresis region refers to a numerical range in which the non-high temperature determination value and the high temperature determination value are set to different values and these are set as upper and lower limits. When the detected temperature exceeds the high temperature judgment value, it is judged to be "high temperature" until the detected temperature falls below the non-high temperature judgment value. When the detected temperature falls below the non-high temperature determination value, it is determined to be "non-high temperature" until the detected temperature exceeds the high temperature determination value. In the example shown in FIG. 7, since the detected temperature exceeds the high temperature determination value at time T1, it is determined that the temperature after this time is high temperature, and the temperature before that time is determined as non-high temperature.

Reference Signs List 1 refrigerator 2 refrigerating chamber 3 ice making chamber 4 upper freezer 5 lower freezer 6 vegetable chamber 7 refrigerating chamber door switch 8 refrigerating chamber left door 9 refrigerating chamber right door 10 upper hinge 11 lower hinge 13 cooler 14 compressor 15 freezer fan 16 machine room 17 power board 18 reactor 19 machine room fan 20 power plug 21 heater load wiring (broken line)
22 defrosting heater 23 refrigerating compartment bottom heater 24 rotary squeegee heater 25 vegetable compartment heater 26 control board 27 control power supply wiring
28 Freezer compartment temperature sensor 29 Refrigerator compartment temperature sensor 30 Control system load wiring (dotted line)
31 Interior light LED
32 Noise filter circuit 33 Converter circuit 34 Inverter module 35 Compressor microcomputer 36 Switching power supply circuit 37 12V system load drive circuit 38 DC/DC conversion circuit 39 Inside control microcomputer 40 Heater drive circuit 41 Heater microcomputer 50 Outer box 51 Inner box 52 Heat insulation Material 53 Rear panel 91 Compressor temperature sensor 92 Substrate temperature sensor 93 12V system load drive circuit (output signal side)
94 12V system load drive circuit (input signal side)
95 12V system load drive wiring (output signal side)
96 12V system load drive wiring (input signal side)

Claims (2)

a compressor;
a compressor temperature sensor arranged near the compressor;
a non-insulated power board for the compressor;
a substrate temperature sensor arranged near the power substrate;
a machine room housing the compressor and a machine room fan acting on fluid around the power board;
If the compressor temperature sensor is high temperature, stop the compressor ,
If the compressor temperature sensor is not at a high temperature, the machine room fan is abnormal and the substrate temperature sensor is at a high temperature, stopping the compressor;
On the other hand, if the compressor temperature sensor is not at a high temperature, the machine room fan is abnormal and the substrate temperature sensor is not at a high temperature, the number of revolutions of the compressor is limited to be low,
A refrigerator according to claim 1, wherein the compressor is driven when the temperature of the compressor temperature sensor is not high and the fan in the machine room is normal. A hysteresis area (dead zone area) is used to determine whether the compressor temperature sensor and/or the substrate temperature sensor are high or not high temperature,
In the hysteresis region, a non-high temperature determination value and a high temperature determination value are set to different values, and a numerical range with these upper and lower limits,
When the detected temperature exceeds the high temperature judgment value, it is judged as "high temperature" until the detected temperature falls below the non-high temperature judgment value,
2. The refrigerator according to claim 1, wherein when the detected temperature falls below the non-high temperature determination value, the refrigerator is determined to be "non-high temperature" until the detected temperature exceeds the high temperature determination value.

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