JP2014112987A - Fan motor drive unit and refrigerator including fan motor drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fan motor drive unit capable of increasing the range of revolutions driven by a fan motor while reducing the power consumption of the fan motor over entire range of revolutions.SOLUTION: A cooling chamber fan motor control unit 137 includes: a fan motor revolutions setting unit 150 that determines the number of revolutions of the fan motor; a calculation unit 151 that calculates the power pulses to be output to the fan motor from the determined number of revolutions; a power voltage output unit 152 that supplies the power by applying a voltage of an amplitude of the pulse; and a duty control signal output unit 153 that controls the duty ratio of the pulses. With this, the fan motor can be driven to rotate in a range of revolutions wider than the control using the pulse amplitude only or duty ratio only. Since the duty ratio can be maintained at high level even when a low speed rotation, the loss at turning OFF can be reduced. By increasing the motor efficiency, the power consumption of the fan motor can be reduced.

Description

  The present invention relates to a fan motor driving device provided with means for controlling the rotational speed of a fan motor by both a pulse amplitude and a duty ratio.

  In domestic refrigerators, it is necessary to keep the interior at a constant temperature regardless of whether the outside air temperature is high or low or whether the door is opened or closed due to use. The speed of the fan motor in the cabinet is variably controlled. In a conventional refrigerator, a DC fan motor is used to change the DC power source applied to the fan motor, thereby changing the rotation speed according to the driving situation (see, for example, Patent Document 1 and Patent Document 2).

  Hereinafter, a fan motor driving device in a conventional refrigerator will be described with reference to the drawings.

  FIG. 11 is a block diagram of a fan motor driving device for a refrigerator described in Patent Document 1. As shown in FIG. 11, the power supply 31 includes a transformer 32, a single input / multiple output rectifier 33, a temperature sensor 34, a temperature compensator 35, a control unit 36, a switching unit 37, and a fan motor 38.

  The operation of the fan motor driving apparatus configured as described above will be described below.

  In FIG. 11, the transformer 32 drops the AC voltage supplied from the power supply 31 to a predetermined AC voltage and supplies it to the rectifier 33. The rectifier 33 converts the AC voltage output from the transformer 32 into a plurality of DC voltages. Here, for example, a DC voltage of 25 V, 17 V, or 12 V is output with respect to a predetermined AC voltage, and the output The number and value of the DC voltage applied can be easily varied.

  At least one temperature sensor 34 is provided inside the refrigerator (not shown), senses the internal temperature, and supplies the temperature compensator 35 to the temperature sensor 34. The temperature compensator 35 corrects the internal temperature sensed by the temperature sensor 34 to the actual internal temperature of the refrigerator and supplies it to the controller 36. The control unit 36 determines the refrigerator cooling load amount based on the internal temperature corrected by the temperature compensator 35, and supplies a control signal corresponding to the determined cooling load amount to the switching unit 37.

  The switching unit 37 switches to a corresponding DC voltage among the plurality of DC voltages of the rectifier 33 in accordance with a control signal supplied from the control unit 36 and supplies it to the fan motor 38. The fan motor 38 has a rotational speed that is variable according to the applied DC voltage, and operates a cooling fan motor (not shown) at high speed, normal speed, and low speed, or stops transmission.

  As described above, in the conventional refrigerator, the fan motor driving device that can detect the cooling load from the refrigerator internal temperature and change the rotational speed of the fan motor 38 by changing the DC voltage according to the load amount. provide.

  FIG. 12 is a block diagram of the fan motor driving device described in Patent Document 2. As shown in FIG. 12, the fan motor 40 is controlled by a motor driving device 41 and an external controller 42.

  The operation of the fan motor driving apparatus configured as described above will be described below.

The external controller 42 generates a control signal Vpwm subjected to pulse width modulation. The external controller 42 changes the duty ratio of the control signal Vpwm according to the target rotational speed of the fan motor 40. When increasing the rotation speed of the fan motor 40, the external controller 42 increases the duty ratio of the control signal Vpwm, and when decreasing the rotation speed of the fan motor 40, the external controller 42 decreases the duty ratio of the control signal Vpwm. When the fan motor 40 is stopped, the external controller 42 substantially sets the duty ratio of the control signal Vpwm to 0 and fixes the control signal Vpwm to a high level or a low level.

  The motor drive device 41 outputs a first drive voltage Vdr1 and a second drive voltage Vdr2 for driving the fan motor 40 according to the control signal Vpwm input from the external controller 42, and the coil current of the fan motor 40 is controlled. And the rotation is adjusted.

Japanese Patent Laid-Open No. 10-185398 JP 2009-55723 A

  However, as in the fan motor driving device described in Patent Document 1, in the control for changing the rotational speed by switching the DC voltage applied to the fan motor, only the voltage that can be output by the transformer can be applied finely. There was a problem that it was difficult to adjust the rotational speed. For example, in a refrigerator, since the required cooling capacity is determined by many conditions such as the outside temperature, door opening / closing, temperature setting in the warehouse, and the amount of food, the cooling fan motor speed control is required to be precise. However, a control method with more stages is necessary, but increasing the number of stages in this control means increasing the number of DC voltages output from the transformer, which simply increases the complexity and cost of the circuit. In other words, the loss of power consumption by the step-down circuit increases. In addition, fan motors generally have a large variation in the number of rotations, and the number of rotations when a predetermined voltage is applied differs one by one. However, in the control of power supply voltage change by a transformer, the difference due to the individual is adjusted. Can not stabilize the quality.

  Here, as in the fan motor driving device described in Patent Document 2, PWM (Pulse-Width-Modulation) control is performed to enable precise rotation speed control. However, since there is only one driving voltage power supply, a power supply voltage that can realize the maximum necessary rotational speed can be used, so that the power supply voltage tends to be too large at the rotational speed that is frequently used on a daily basis. In other words, the duty ratio is usually reduced, but in PWM control, the power efficiency of the circuit decreases as the duty ratio becomes smaller due to transistor ON / OFF switching loss and OFF power consumption. . Therefore, even when PWM control is used, there is a problem that the amount of power consumption increases on a daily basis in order to realize the maximum number of rotations that is less frequently used.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a fan motor driving device capable of precisely controlling the rotational speed within a wide rotational speed selection range without impairing power efficiency. And

In order to solve the above-described conventional problems, a fan motor driving device of the present invention includes a fan motor and a fan motor control device that controls operation of the fan motor, and the fan motor control device includes: A rotation speed setting means for determining the rotation speed, a calculation means for calculating a pulse output to the fan motor from the determined rotation speed, a power supply voltage output means for controlling the amplitude of the pulse, and a duty ratio of the pulse Duty control signal output means.

  Thereby, since the rotational speed is controlled by changing the power supply voltage applied to the fan motor, it is possible to widen the rotational speed range of the fan motor that can be realized as compared with the case where one power supply voltage is used. Further, since the rotational speed can be controlled by changing the duty ratio simultaneously with the power supply voltage, the rotational speed can be controlled more precisely than the control using only the power supply voltage.

  Since the fan motor drive device of the present invention can select a combination of the power supply voltage and the duty ratio, by selecting a circuit having a large duty ratio in accordance with the rotational speed, the power consumption at the time of OFF is always suppressed. Efficient operation can be performed. Conversely, by selecting a circuit with a small duty ratio, it is possible to provide a fan motor driving device that can perform control in accordance with the use situation, such as control for rapidly increasing the rotational speed.

Front view of the refrigerator in Embodiment 1 of the present invention AA sectional view in FIG. Upper rear view of the refrigerator in the first embodiment Block diagram of the DC power supply system of the refrigerator in the first embodiment Block diagram of the fan motor drive device in the first embodiment Flowchart of normal fan motor operation in the first embodiment Flowchart of cooling chamber fan motor start control in the first embodiment Rotational speed characteristic diagram of cooling chamber fan motor in the first embodiment Power consumption graph of DC fan motor Flowchart at power-on of refrigerator in embodiment 2 of the present invention Block diagram of the fan motor driving device described in Patent Document 1 Block diagram of the fan motor driving device described in Patent Document 2

  The invention described in claim 1 includes a fan motor and a fan motor control device that controls the operation of the fan motor, and the fan motor control device includes a rotation speed setting means that determines the rotation speed of the fan motor; , Calculating means for calculating a power supply pulse to be output to the fan motor from the determined rotational speed; power supply voltage output means for supplying power to the fan motor; and outputting a duty control signal for controlling the duty ratio of the pulse By providing the duty control signal output means, the power supply voltage applied to the fan motor is changed to control the rotational speed, so that the fan motor rotational speed range that can be realized is wider than when one power supply voltage is used. it can. Further, since the rotational speed can be controlled by changing the duty ratio simultaneously with the power supply voltage, the rotational speed can be controlled more precisely than the control using only the power supply voltage. In addition, since a combination of power supply voltage and duty ratio can be selected, by selecting a circuit with a large duty ratio according to the number of revolutions, power consumption during OFF can be suppressed and always efficient operation can be performed. Can do. Conversely, by selecting a circuit with a small duty ratio, it is possible to provide a fan motor driving device that can perform control in accordance with the use situation, such as control for rapidly increasing the rotational speed.

  According to a second aspect of the present invention, in the first aspect of the present invention, the calculation unit selects a minimum pulse amplitude at which the fan motor can realize the rotation number output by the rotation number setting unit, and the power source The voltage output means outputs an amplitude control voltage having the minimum pulse amplitude. As a result, among the combinations of pulse amplitude and duty ratio that can achieve the target rotational speed, the combination with the largest duty ratio is selected, so that the power consumption during OFF can be suppressed and the most efficient operation can be performed. it can.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the fan motor driving device includes at least one of a power source device that generates a DC power source used by the fan motor and a DC power source. Two load devices and a load control device for controlling the operation of the load device, the fan motor is not started when the load device is operating, and the fan motor is operated after the operation of the load device is completed. It is characterized by starting. As a result, an increase in the current capacity of the power supply device can be suppressed, and a reduction in size and cost can be realized.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the fan motor control device uses a DC power source in which the load device has a voltage having the minimum pulse width. The fan motor is driven with a pulse width one step larger than the minimum pulse width. Thereby, since each capacity | capacitance of a several drive power supply circuit can be restrained to one load, the increase in the current capacity of each circuit can be suppressed, and size reduction and cost reduction can be implement | achieved.

  According to a fifth aspect of the present invention, in the invention according to any one of the first to fourth aspects, the fan motor control device includes a rotational speed detection means for detecting a rotational speed of the fan motor, and the calculation. The means is characterized in that the pulse is calculated by feedback calculation between the rotation speed setting means and the rotation speed detection means. Thereby, the difference in the rotation speed due to the individual difference of the fan motor can be detected, and the control can be surely performed so that the predetermined rotation speed is obtained, so that stable fan motor driving can be performed. In addition, since the combination of the pulse amplitude and the duty ratio can be calculated in consideration of individual differences, a more efficient operation can be selected.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the detection timing of the rotational speed detection means is when the fan motor is activated. As a result, by aligning the rotation speed detection timing, the rotation speed can be detected more stably without being affected by the temperature rise due to the operation, so that an appropriate pulse calculation can be realized.

  According to a seventh aspect of the present invention, in the fifth aspect of the present invention, the detection timing of the rotation speed detecting means is limited to one time at the first start-up when the fan motor driving device is turned on, and feedback control is performed. The contents are stored in a nonvolatile memory. As a result, not only the situation of the fan motor itself but also the influence of the surroundings such as the oil viscosity of the motor bearing due to the change of the ambient temperature can be reduced, so the rotational speed of the fan motor is always detected in a stable state. . Further, by storing in the non-volatile memory, the initial feedback control is always applied, and even if the usage environment changes thereafter, the feedback control is not affected.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, wherein the power supply voltage output means and the duty control signal output means do not depend on the output of the arithmetic means, and the fan When the motor is started, each maximum voltage is output, and after a predetermined time has elapsed, a voltage corresponding to the output of the calculation means is output. Thereby, the torque at the time of fan motor starting can be enlarged, and starting failure can be prevented. Also, since it has multiple power supply voltages, multiple power supply circuits are required, but by fixing the power supply at startup that requires the most power, the capacity of other power supply circuits can be reduced. Therefore, the circuit can be reduced in size and cost.

  Invention of Claim 9 is a refrigerator provided with the fan motor drive device as described in any one of Claims 1-8, Since the amount of cold air circulation in the refrigerator compartment can be precisely controlled. A refrigerator capable of delicate temperature control can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
Hereinafter, a first embodiment of the present invention will be described.

  1 is a front view of the refrigerator according to the first embodiment, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is an upper rear view of the refrigerator according to the first embodiment.

  1 to 3, a heat insulating box 101 which is a refrigerator main body of the refrigerator 100 includes an outer box 102 mainly using a steel plate, an inner box 103 formed of a resin such as ABS, an outer box 102 and an inner box 103. And a foam heat insulating material such as hard foam urethane that is foam-filled in the space between the two, and is insulated from the surroundings and partitioned into a plurality of storage chambers. A refrigeration room 104 as a first storage room is provided at the top, and a second freezing room 105 as a fourth storage room and an ice making room 106 as a fifth storage room are provided side by side under the refrigeration room 104. The first freezing chamber 107 as the second storage chamber is disposed below the second freezing chamber 105 and the ice making chamber 106, and the vegetable chamber 108 as the third storage chamber is disposed at the bottom. ing.

  The refrigerating room 104 includes a refrigerating room right door 104a and a refrigerating room left door 104b, which are rotary doors, and a refrigerating room shelf 104c and a refrigerating room case 104d are appropriately disposed therein, so that the storage space can be easily arranged. doing. The left wall surface and the right wall surface in the refrigerator compartment 104 have refrigerator door open / close detection means (not shown), respectively. When the refrigerator door is closed, the switch of the refrigerator door open / close detection means is mechanically switched. Opening / closing states of the right door 104a and the left door 104b are detected.

  On the other hand, the other storage rooms have drawer doors, the second freezer compartment door 105a has a second freezer compartment case 105b, the icemaker door 106a has an icemaker case 106b, and the first freezer compartment. An upper freezer compartment case 107b and a lower freezer compartment case 107c are placed on the door 107a, and an upper vegetable compartment case 108b and a lower vegetable compartment case 108c are placed on the frame attached to the door, respectively. The partition beam 110 that partitions the opening between the first freezer compartment 107 and the ice making chamber 105 is provided with a freezer compartment door open / close detection means (not shown) that detects opening and closing of the first freezer compartment door 107a and the ice making chamber door 106a. . The freezer compartment door open / close detection means is constituted by two magnetic sensing elements, and includes magnets (not shown) incorporated in the freezer compartment packing 107d and the ice compartment packing 106c provided in the first freezer compartment door 107a and the ice making compartment door 106a. ) To detect whether the first freezer compartment door 107a and the ice making compartment door 106a are opened or closed.

  It should be noted that the refrigerator door open / close detection means may be constituted by a magnetic detection element, or the freezer compartment door open / close detection means may be fixed by a mechanical switch, and the installation position is a position with few malfunctions due to the structure of the refrigerator and the door configuration. It is only necessary to be appropriately arranged. Moreover, you may provide the door opening / closing detection means which detects opening / closing of the 2nd freezer compartment door 106a and the vegetable compartment door 108a as needed.

The temperature detection means 112, which is a temperature sensor, is installed in the refrigerator compartment 104 and the ice making chamber 105, and the refrigerator 100 controls each storage room to have an appropriate temperature by causing the control device to detect the temperature of each part in the storage room. . The refrigerated room 104 is set in a refrigerated temperature zone, which is a temperature at which freezing is not performed for refrigerated storage, and is usually 1 to 5 ° C. Illumination devices 113 are arranged in the vertical direction on the left wall surface and the right wall surface in the refrigerator compartment 104, respectively. The vegetable room 108 has a refrigeration temperature range equivalent to the refrigeration room 104 or a vegetable temperature range of 2 ° C. to 7 ° C. that is set at a slightly higher temperature. The first freezer compartment 107 is set in a freezing temperature zone, and is usually set at −22 ° C. to −15 ° C. for frozen storage, but in order to improve the frozen storage state, for example, −30 ° C. It may be set at a low temperature of -25 ° C.

  The second freezer compartment 105 has the same freezing temperature zone as the first freezer compartment 107 or a slightly higher temperature setting of −20 ° C. to −12 ° C. The ice making chamber 106 makes ice with an automatic ice maker (not shown) provided at the upper part of the room with water sent from a water storage tank (not shown) in the refrigerator compartment 104 by a water supply pump (not shown), An ice tray (not shown) is twisted and deiced and stored in the ice chamber case 106b.

  Note that the temperature detecting means 112 may be provided in other storage rooms as necessary, or a plurality of temperature detection means 112 may be provided in one storage room. Moreover, the method of deicing from the ice tray does not need to be twisted, and another appropriate means such as defrosting by melting the surface by heating may be used.

  The top surface portion of the heat insulation box 101 has a stepped recess shape toward the back of the refrigerator, and a machine room 101a is formed in the stepped recess. In the machine room 101a, a condenser 114, a machine room fan motor 115, and a compressor 116 are installed in order from the windward side. By driving the machine room fan motor 115, air in the upper part of the refrigerator is sucked and the condenser 114 is placed. And the compressor 116 is air-cooled.

  The refrigeration cycle is formed of a series of refrigerant flow paths sequentially including a compressor 116, a condenser 114, a capillary (not shown) as a decompressor, and a cooler 120, and is a hydrocarbon-based refrigerant as a refrigerant. For example, isobutane is enclosed.

  The compressor 116 is a reciprocating compressor that compresses refrigerant by reciprocating a piston in a cylinder. In the case of a refrigeration cycle using a three-way valve or a switching valve for the heat insulation box 101, those functional parts may be disposed in the machine room 101a.

  In this embodiment, the decompressor constituting the refrigeration cycle is a capillary. However, an electronic expansion valve that can freely control the flow rate of the refrigerant driven by the pulse motor may be used.

  In the present embodiment, the matters relating to the main part of the invention described below are a type in which a compressor room is provided by providing a machine room in the rear region of the lowermost storage room of the heat insulation box 101, which has been conventionally common. It may be applied to other refrigerators.

  A cooling chamber 121 for generating cool air is provided on the back surface of the first freezing chamber 107, and the storage chamber consisting of the second freezing chamber 105, the ice making chamber 106, and the first freezing chamber 107 is separated from the cooling chamber 110. Therefore, a partition member 122 is configured. A cooler 120 is disposed in the cooling chamber 121, and a radiant made of a glass tube for defrosting the frost and ice adhering to the cooler 120 and its periphery during cooling in the lower space of the cooler 120. A heating unit 123 is provided, and further, a drain pan 124 for receiving defrost water generated at the time of defrosting and a drain tube 125 penetrating from the deepest portion to the outside of the chamber are formed at the lower portion thereof, and evaporated to the outside of the downstream side of the chamber. A dish 126 is configured.

  Instead of the radiant heating means 123, another shape heating means such as a pipe heater attached to the cooler 120 may be used, or the radiant heating means 123 and another shape heating means may be used in combination.

The partition member 122 is provided with a cooling chamber fan motor 127 for circulating the cool air to the storage chambers, and a distribution air passage 128 for distributing the cool air discharged from the cooling chamber fan motor 127 to the respective storage chambers. The damper 1 is located downstream of the distribution air passage 128 and upstream of the refrigerator compartment 104.
29 is installed. The cooling chamber fan motor 127 is a DC fan motor with a sensor, and has a function capable of PWM control by applying a power supply voltage and a duty signal.

  The control device 130 is installed together with the power supply device 131 in the substrate storage unit 132 installed on the back surface of the refrigerator 100. The control device 130 and the power supply device 131 may be configured on a single substrate.

  FIG. 4 is a block diagram of the DC power supply system 100a (fan motor driving device) of the refrigerator in the first embodiment.

  As shown in FIG. 4, the DC power supply system 100 a (fan motor driving device) of the refrigerator 100 includes loads such as a control device 130, a power supply device 131, and a cooling chamber fan motor 127. The control device 130 includes a temperature detection means 112, a door opening / closing detection means 133, an outside air temperature detection means 134, a compressor rotation speed detection means 135, a microcomputer 136 that performs calculation, a cooling room fan motor control device 137, and a machine room fan motor. A control device 138, a lighting device control device 139, a damper control device 140, and an automatic ice maker control device 141 are provided. The loads are the cooling room fan motor 127, the machine room fan motor 115, the lighting device 113, the damper 129, the automatic ice making machine 142, and the water supply pump 143.

  In addition, in order to know the driving situation and the external environment in more detail, the control device is provided with means for detecting the illuminance inside / outside of the storage, or a notification means by sound or light such as a buzzer or an electric bulletin board for notification or warning of the driving situation. May be provided.

  FIG. 5 is a block diagram of the cooling chamber fan motor control device according to the first embodiment.

  The cooling chamber fan motor control device 137 includes a fan motor rotation speed setting unit 150, a calculation unit 151, a power supply voltage output unit 152, and a duty control signal output unit 153, and supplies power for driving the cooling chamber fan motor 127. A fan motor rotation speed detection means 154 is provided to detect the rotation speed of the cooling chamber fan motor 127.

  FIG. 6 is a flowchart regarding control of the cooling chamber fan motor when the refrigerator is turned on in the first embodiment.

  FIG. 7 is a flowchart relating to control of the cooling chamber fan motor during normal refrigerator operation in the first embodiment.

  The operation | movement and effect | action are demonstrated about the refrigerator 100 comprised as mentioned above.

  First, the operation of the refrigeration cycle will be described. The refrigeration cycle is operated by a signal from a control device (not shown) according to the set temperature in the refrigerator, and the cooling operation is performed. The high-temperature and high-pressure refrigerant discharged by the operation of the compressor 116 is condensed to some extent by the condenser 114 and further disposed on the side surface and the back surface of the heat insulation box body 101 which is the refrigerator main body, and the front opening of the heat insulation box body 101. The refrigerant is condensed and liquefied while preventing water droplets in the heat insulating box 101 via a refrigerant pipe (not shown) or the like, and reaches a capillary tube (not shown). After that, the capillary tube is depressurized while exchanging heat with a suction pipe (not shown) to the compressor 116 and becomes a low-temperature and low-pressure liquid refrigerant and reaches the cooler 112.

Here, in the cooling chamber 121, the air in each storage chamber collected by the operation of the cooling chamber fan motor 127 is heat-exchanged with the liquid refrigerant by the cooler 120, and the refrigerant in the cooler 120 evaporates. At this time, the air returned from the storage chamber becomes cold air for cooling each storage chamber again in the cooling chamber 121. The low-temperature cold air flows from the cooling chamber fan motor 127 through the distribution air passage 128 and is divided using other air passages and dampers 129, and is stored in the refrigerator compartment 104, the second freezer compartment 105, the ice making compartment 106, and the first freezer compartment. 107, the vegetable compartment 108 is cooled to each target temperature zone.

  When it is confirmed that the temperature detecting means 112 has been cooled to a predetermined temperature, a command is issued by the microcomputer 136, the cooling chamber fan motor 127 and the compressor 116 are stopped, and cooling is stopped.

  Next, the rotation speed control of the cooling chamber fan motor 127 will be described. FIG. 8 shows the relationship among the power supply voltage, duty control voltage, and rotation speed of the cooling chamber fan motor 127. The power supply voltage applied to the cooling chamber fan motor 127 is selected from Vc1 to Vcn. n is an integer of 2 or more, and the cooling chamber fan motor 127 can change the rotational speed characteristic with respect to the duty ratio by applying a plurality of different voltages. Accordingly, since the number of revolutions is controlled by changing the power supply voltage applied to the cooling chamber fan motor 127, the range of the number of revolutions of the cooling chamber fan motor 127 that can be realized is wider than when one power supply voltage is used. it can. Here, by using voltages necessary for other load devices for Vc1 to Vcn, it is not necessary to provide a power supply circuit dedicated to the cooling chamber fan motor 127, and the circuit can be reduced in size and cost.

  In the present embodiment, the power source Vc1 = 14V for the lighting device 113, the power source Vc2 = 12V for the automatic ice maker 142 and the water supply pump 143, and the power source Vc3 = 8V for the damper driving device are selected. Note that it is not necessary to use all the power supply voltages as the power supply voltages of the cooling chamber fan motor 127, and a dedicated power supply circuit may be made.

  By operating the duty ratio for each of the power supply voltages Vc1 to Vc4, the average value of the power supply voltage applied to the cooling chamber fan motor 127 changes, and the rotation speed can be controlled more finely. In this embodiment, it is assumed that the low level has a duty ratio of 0%, and the duty control signal linearly changes from 0 to 100% between 1.5 to 3.5V. Note that the high level may be a duty ratio of 0%, and the range of the duty control signal may be a value that is easier to use for a circuit that uses it. As a result, the rotational speed can be controlled by changing the duty ratio at the same time as the power supply voltage, so that the rotational speed can be controlled more precisely than the control using only the power supply voltage.

  In order to control the cooling chamber fan motor 127 having the above characteristics, the cooling chamber fan motor control device 137 has the structure of FIG. 5 and drives the cooling chamber fan motor according to the flowchart shown in FIG. In FIG. 6, when the microcomputer 136 determines that the cooling chamber fan motor 127 needs to be operated (S001), the cooling chamber fan motor control device 137 issues a command of the assumed rotation speed Nr by the fan motor rotation speed setting means 150 ( Next, the power supply voltage Vc and the duty control signal Vs corresponding to Nr are selected by the calculation means 151 from the rotational speed characteristics of FIG. 8 (S003) and transmitted to the power supply voltage output means 152 and the duty control signal output means 153 (S002). First, a maximum Vc (for example, Vc4 = 14 V) and a duty control signal Vs (for example, 3.5 V) that outputs a duty ratio of 100% are output (S004). Then, after a predetermined time has elapsed, the voltage is changed to the command voltage from the calculation means 151 (S005).

At this time, the calculation means 151 selects the smallest Vc among the selectable power supply voltages Vc. That is, Vc1 is selected when the rotational speed is N1 or less, Vc2 is selected when N1 to N2, Vc3 is selected when N2 to N3, and Vc4 is selected when N3 or more. As a result, Vc is always the smallest value among the choices, and the duty ratio is selected to be the highest, so that the power-off time is shortened and the power loss in the circuit when the power is off can be minimized. Can be operated with the highest power efficiency. FIG. 9 is a graph showing the relationship of the power consumption with respect to the power supply voltage Vc when the same rotational speed is obtained in the same fan motor. As shown in FIG. 9, when rotating at the same rotation speed, it can be seen that the power consumption can be reduced by reducing the power supply voltage Vc (increasing the duty ratio). Moreover, by starting with the maximum power supply voltage, the starting torque of the cooling chamber fan motor 127 can be reliably ensured, and the occurrence of starting failure can be suppressed. Since the cooling chamber fan motor 127 is located immediately downstream of the cooler 120, frosting and icing are likely to occur, and particularly, there is a high possibility of starting failure. Therefore, securing the starting torque is very important.

  When the cooling chamber fan motor 127 rotates, the actual rotation speed Np is detected by the fan motor rotation speed detection means 154 (S006), and is compared with the assumed rotation speed Nr. 8 is corrected using the difference ΔN = Nr−Np as a correction rotation number (that is, replaced with N1 = N1−ΔN, N2 = N2−ΔN, N3 = N3−ΔN) again. The power supply voltage Vc and the duty control signal Vs are calculated (S007), transmitted to the power supply voltage output means 152 and the duty control signal output means 153, and the applied voltage is corrected (S008). In general, fan motors vary in voltage-rotational speed characteristics depending on the individual, so by calculating ΔN and correcting the calculation, a stable rotational speed without individual variations can be obtained, and the cooling capacity of all refrigerators 100 can be increased. It can be stabilized.

  Although the rotation speed correction in S006 to S008 can be performed periodically, the rotation speed of the fan motor, which changes depending on the driving situation, can be kept constant. However, by limiting the timing, the circuit can be simplified and the calculation power can be reduced. It can also be done.

  FIG. 7 is a flowchart regarding the activation control of the cooling chamber fan motor 127.

  When the microcomputer determines that the cooling chamber fan motor 127 needs to be rotated (S101), the microcomputer issues a command to the cooling chamber fan motor control device 137, and the fan motor rotation number setting means 150 calculates the assumed rotation number. (S102) and transmitted to the calculation means 151. Next, the calculation means 151 determines whether other load devices are in operation (S103). If not operating here, the minimum power supply voltage Vc and the duty control signal Vs at that time are selected according to the assumed rotation speed as described above (S104), and output from the power supply voltage output means 152 and the duty control signal output means 153. Then, normal fan motor operation is performed (S105).

  On the other hand, when it is determined in S103 that another load device is in operation, it is determined whether the load device is the machine room fan motor 115 (S106). If it is not the machine room fan motor 115 (that is, any one of the lighting device 113, the damper 129, the automatic ice maker 142, and the water supply pump 143), the cooling room fan motor 127 is not operated (S107) and the process returns to S103.

When the load during operation is the machine room fan motor 115, the optimum power supply voltage Vck (k is any one of 1 to n) in the calculation means 151, and is the smallest value that can be selected as described above. ) And the duty control signal Vs at that time is calculated (S108), and then it is determined whether the calculated power source voltage Vck is used by the machine room fan motor 115 (S109). If the machine room fan motor 115 does not use the power supply voltage Vck, the power supply voltage Vck and the duty control signal Vs calculated in S108 are output from the power supply voltage output means 152 and the duty control signal output means 153 to perform normal fan motor operation. Perform (S110). If the machine room fan motor 115 uses the power supply voltage Vck in S109, the calculation of k = k + 1 is performed, the power supply voltage Vck and the duty control signal Vs are recalculated (S111), and the power supply voltage output means 152 and the duty Normal fan motor operation is performed by the control signal output means 153 (S112).

  As a result, the cooling chamber fan motor 127 does not start when other load devices other than the machine room fan motor 115 are operating, so the power capacity used by the other load devices is the cooling chamber fan motor 127. Since it can be supplemented by the power supply capacity to be used, the total amount of current required for the power supply can be reduced, and the power supply circuit can be reduced in size and cost. Here, since the other load devices are all load devices that perform a temporary operation, there is no particular problem with a decrease in cooling capacity due to a delay in the activation of the cooling chamber fan motor 127.

  Further, since the power supply voltage of the machine room fan motor 115 and the power supply voltage of the cooling room fan motor 127 can always be selected, the current capacity of each voltage can be minimized. Therefore, each circuit can be reduced in size and cost. Furthermore, since one power supply voltage is not used at the same time, a voltage drop due to a temporary power supply load increase can be suppressed, stable operation can be ensured, and a reduction in the life of each load device can be suppressed. . Thereby, the quality over the long term of the refrigerator 100 can be improved.

  The machine room fan motor 115 predicts the operating state of the refrigerator 100 in advance by adjusting the power supply voltage-rotation speed (or air volume) characteristic in advance so that the same power supply voltage is not used simultaneously with the cooling room fan motor 127. The cooling chamber fan motor 127 can be operated with an efficient power source having the largest duty ratio. Further, by operating the machine room fan motor 115 under the control of the cooling room fan motor 127, the power consumption of the machine room fan motor 115 can be further reduced.

  As described above, in this embodiment, since the rotational speed is controlled by changing the power supply voltage applied to the cooling room fan motor 127, the cooling room fan can be realized as compared with the case of using one power supply voltage. Not only can the rotational speed range of the motor 127 be widened, but also the rotational speed can be controlled by changing the duty ratio at the same time as the power supply voltage, so that the rotational speed can be controlled more precisely than control using only the power supply voltage. In particular, by adopting this control for the cooling chamber fan motor 127 of the refrigerator 100, the amount of cool air circulating in the refrigerator 100 can be precisely controlled, so that delicate temperature management becomes possible, and the value of the refrigerator 100 is improved. It can be greatly increased. In general, frost constantly adheres to the refrigerator cooler during operation. In the present embodiment, frost adhering to the cooler 120 and its periphery is periodically removed by the radiant heating means 123. Accordingly, in the cooling chamber fan motor 127, since the air blowing load is constantly fluctuating, stable cooling regardless of the idea state can be achieved by precisely controlling the actual rotational speed Np in this way. Since the capability can be secured, the quality of the refrigerator 100 can be improved.

  Furthermore, by selecting the lowest power supply voltage Vc among the selectable power supply voltages Vc, the power supply voltage Vc is always the smallest value among the choices and the duty ratio is selected to be the highest, so the power supply is turned off. Thus, the power loss in the circuit when the power is OFF can be minimized, and the most efficient operation can be performed. At this time, by using the voltage necessary for the other load device as the power supply voltage Vc, it is not necessary to provide a power supply circuit dedicated to the cooling chamber fan motor 127, and the circuit can be reduced in size and cost.

  Further, since the cooling chamber fan motor 127 does not start when other load devices other than the machine room fan motor 115 are operating, the power capacity used by the other load devices is used by the cooling chamber fan motor 127. Therefore, the total amount of current required for the power supply can be reduced, and the power supply circuit can be reduced in size and cost.

(Embodiment 2)
FIG. 10 is a flowchart at power-on of the refrigerator in the second embodiment of the present invention.

  In addition, although description is abbreviate | omitted about the part which can apply the structure similar to Embodiment 1, and the same technical idea, as long as there is no malfunction, it can apply combining this Embodiment with the structure of Embodiment 1. Is possible.

  About the refrigerator in Embodiment 2 of this invention comprised as mentioned above, the operation | movement is demonstrated below.

  In FIG. 10, when it is determined that the power of the refrigerator 100 is turned on for the first time (S202), first, the fan motor rotational speed setting means 150 issues a command of the assumed rotational speed Nr (S203), and the power supply voltage Vc corresponding to Nr and The duty control signal Vs is output from the power supply voltage output means 152 and the duty control signal output means 153 (S204), and the cooling chamber fan motor 127 is started. Next, the rotational speed Np of the cooling chamber fan motor 127 is detected by the fan motor rotational speed detecting means 154 (S205), and detected by the rotational speed Nr designated by the fan motor rotational speed setting means 150 and the fan motor rotational speed detecting means 154. The speed difference ΔN (= Nr−Np) with respect to the speed Np is calculated, the power supply voltage Vc and the duty control signal Vs are recalculated (S206), and the calculation data is stored in the nonvolatile memory (S207). Thereafter, after the power is turned on again, since data exists in the nonvolatile memory, the fan motor rotation speed detection flow is omitted, and the cycle of the normal refrigerator operation control mode is performed.

  This not only simplifies the control device by limiting the timing of detecting the number of rotations of the fan motor and feedback control, but also when the refrigerator 100 is turned on, the temperature inside the refrigerator or the refrigerator is close to room temperature. By doing so, the ambient temperature of each fan motor is stabilized, so that the rotational speed of the fan motor is always detected in a stable state. Therefore, since the characteristics of each fan motor can be accurately grasped by an inexpensive system, appropriate feedback can be performed and stable cooling performance can be ensured. In addition, by storing in the non-volatile memory, the initial feedback control is always applied, and even if the usage environment changes, it is not necessary to affect the feedback control. As a result, more stable cooling performance can be realized. It becomes.

  In addition, since the first power-on stored in the nonvolatile memory of the refrigerator 100 is the final inspection process in the production line, the ambient temperature of the cooling chamber fan motor 127 and the refrigerator 100 can be made constant throughout the year. Therefore, more stable feedback control can be performed.

  The fan motor drive device according to the present invention can finely control the rotational speed control of a motor driven by a DC power source from high speed to low speed without increasing the power consumption. First, it can be applied to various electric devices using a motor.

100 Refrigerator 100a DC power supply system (fan motor drive device)
113 Illumination device (load device)
115 Machine room fan motor (load device)
127 Cooling chamber fan motor 129 Damper (load device)
131 Power Supply Device 137 Cooling Room Fan Motor Control Device 138 Machine Room Fan Motor Control Device (Load Control Device)
139 Lighting device control device (load control device)
140 Damper control device (load control device)
141 Automatic ice machine control device (load control device)
142 Automatic ice maker 143 Water supply pump 150 Fan motor rotation speed setting means 151 Calculation means 152 Power supply voltage output means 153 Duty control signal output means 154 Fan motor rotation speed detection means

Claims (9)

A fan motor, and a fan motor control device that controls the operation of the fan motor, wherein the fan motor control device includes a rotation speed setting means that determines a rotation speed of the fan motor, and the fan motor based on the determined rotation speed. Calculating means for calculating a power supply pulse to be output to the power supply, power supply voltage output means for supplying power to the fan motor, and duty control signal output means for outputting a duty control signal for controlling the duty ratio of the pulse. The fan motor drive device characterized by the above-mentioned. The calculation means selects a minimum pulse amplitude at which the fan motor can realize the rotation speed output by the rotation speed setting means, and the power supply voltage output means outputs an amplitude control voltage that becomes the minimum pulse amplitude. The fan motor drive device according to claim 1, wherein the fan motor drive device is a fan motor drive device. The fan motor drive device includes a power supply device that generates a DC power supply used by the fan motor, at least one load device that uses the DC power supply, and a load control device that controls the operation of the load device, 3. The fan motor drive device according to claim 1, wherein the fan motor is not started when the load device is operating, and the fan motor is started after the operation of the load device is finished. 4. The fan motor control device drives the fan motor with a pulse width one step larger than the minimum pulse width when the load device uses a DC power supply having a voltage with the minimum pulse width. The fan motor drive device as described in any one of Claim 1 to 3. The fan motor control device includes a rotation speed detection means for detecting the rotation speed of the fan motor, and the calculation means calculates a pulse by a feedback calculation between the rotation speed setting means and the rotation speed detection means. The fan motor drive device according to any one of claims 1 to 4. 6. The fan motor drive device according to claim 5, wherein the detection timing of the rotation speed detection means is when the fan motor is activated. The detection timing of the rotation speed detection means is limited to once at the first startup of the fan motor when the fan motor driving device is turned on, and the content of feedback control is stored in a nonvolatile memory. 5. The fan motor drive device according to 5. The power supply voltage output means and the duty control signal output means do not depend on the output of the calculation means, but output the maximum voltages at the time of startup of the fan motor, and respond to the output of the calculation means after a certain time has elapsed. The fan motor drive device according to any one of claims 1 to 7, wherein a voltage is output. The refrigerator provided with the fan motor drive device as described in any one of Claim 1 to 8.