JP2640087B2 - Power frequency detector for refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator having operating devices affected by a power supply frequency and controlled by a control device such as a microcomputer, and using a device operating in synchronization with the power supply frequency. The present invention relates to a power supply frequency detection device for a refrigerator that can detect an accurate power supply frequency without providing a detection circuit.

[0002]

2. Description of the Related Art As a device which needs to detect a power supply frequency, for example, a motor damper (using an AC motor) device used in a microcomputer controlled refrigerator as disclosed in Japanese Patent Application Laid-Open No. Sho 62-24084 is disclosed. There is a defrost control timer or the like used for determining a starting point for starting a defrost operation. In the damper device, the AC motor is energized for a certain period of time to open and close the baffle plate, but the AC motor rotates in synchronization with the power supply frequency. Therefore, the power supply frequency must be detected.

In order to detect the power supply frequency,
For example, there is a type in which the voltage of an AC power supply is stepped down by a transformer, the waveform is shaped by a waveform shaping circuit, and input to a control device such as a microcomputer to detect the frequency. According to this detection method, a waveform shaping circuit is required. As a result, the equipment becomes complicated and tends to be expensive, and the noise that tends to be mixed in the electric wire from the power supply to the waveform shaping circuit is detected and the frequency is detected, so that the power supply frequency may be erroneously detected.

Accordingly, in the present invention, in order to easily and accurately detect the power supply frequency without such inconvenience, the time required for the motor damper device operating in synchronization with the power supply frequency to change from a certain state to a certain state is determined by a microcomputer. An object of the present invention is to provide a power supply frequency detecting device for a refrigerator, which measures an internal clock and determines the frequency of the power supply frequency using the measured time.

[0005]

According to the present invention, there is provided a refrigerator comprising: an AC motor which rotates in synchronization with a power supply frequency; a gear, a cam and a pin for converting a rotational motion of the motor into a reciprocating motion;
A baffle plate that opens and closes by the reciprocating motion of the pin to adjust the flow rate of cool air to the storage room of the refrigerator, and a signal is output when the cam changes from one state to another state to detect the rotational position of the cam. A damper device having a switch means, an arm provided to reciprocate with the rotation of the cam, and an arm for turning on and off the switch means, and controlling the supply of cool air to the storage chamber by opening and closing the baffle plate. And in particular, the controller drives the AC motor to change the baffle plate from a certain state to a certain state when the refrigerator is turned on, and operates the damper device at least one cycle. The power supply frequency required for controlling the energization time to the AC motor is measured by measuring the time of this one cycle.

[0006]

When the AC motor is driven, the gears and cams rotate, the pins move back and forth, and the baffle plate opens and closes. However, since the AC motor rotates in synchronization with the power supply frequency, the power is turned on by the control device (ie, The power supply frequency is detected by operating the damper device at least one cycle when the refrigerator is installed and the outlet is inserted and when the power is restored after the power failure) and the time of this one cycle is measured.
Since the time of this one cycle changes according to the power supply frequency,
For example, based on the time required when the power supply frequency is 50 Hz, the power supply frequency can be detected by examining (i.e., comparing) the length relationship with the measured time (that is, the measured time is better than the measured time). Power supply frequency is 6 if shorter
0 Hz, power supply frequency is 50 if same or longer
Hertz). A so-called self-contained power supply frequency detection device that performs both operations of detecting the power supply frequency and controlling the damper device after the detection because the control device controls the energization time to the AC motor according to the detected power supply frequency. Can be provided. In this case, a waveform shaping circuit is unnecessary.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view of a main part of a damper device of a refrigerator according to the present invention, and FIGS. 2A to 2D are operation explanatory diagrams for explaining a positional relationship among a first cam, an arm, and switch means. FIG. 4 is an electric circuit diagram including the control device of the present invention, FIG. 4 is a time chart illustrating a frequency detection operation in the control device, FIG. 5 is a longitudinal sectional view of the refrigerator of the present invention, and FIG. 3 is a horizontal sectional view taken along line AA of FIG.

FIG. 5 shows a refrigerator 1 for home use. Reference numeral 2 denotes a heat-insulating box, and the inside thereof is vertically divided by a heat-insulating partition wall 3, and a freezing room F as a first room and a refrigerator room R as a second room below the heat-insulating partition 3. Is formed. Reference numerals 6 and 7 denote heat-insulating doors for independently opening and closing the front openings of the freezer compartment F and the refrigerator compartment R, respectively.
A cooling chamber is formed in the partition wall 3, and a cooler 10 that forms a part of a refrigeration cycle is housed in the cooling chamber. A duct 11 communicating with the cooling chamber 8 and the two chambers F and R is formed behind the cooler 10. Air cooled by the cooler 10 by a blower 12 provided in the duct 11, that is, cool air Is forcibly blown out into the duct 11.

Reference numeral 12M denotes a motor for driving the blower 12. The cool air blown out to the duct 11 is blown out from the discharge port 14 to the freezer compartment F and from the discharge port 15 to the refrigerator compartment R. Reference numeral 17 denotes a damper device provided in the refrigerator compartment R for opening and closing the discharge port 15. The damper device 17 opens and closes the discharge port 15 with a baffle plate 18 which is rotatable in the front-rear direction based on the temperature in the refrigerator compartment R. For example + 7 ° C
And an average of + 5 ° C between and + 3 ° C. 19 is a heat insulating cover of the damper device 17.

Reference numeral 20 denotes a machine room 21 below the refrigerator 1
This is an electric compressor that is installed in the refrigerator and forms a part of a refrigeration cycle together with the cooler 10. In the machine room 21, a condenser 22 which similarly constitutes a part of a refrigeration cycle, and a blower 23 for cooling the condenser 22 and the electric compressor 20 are installed. Reference numeral 5 denotes an operation panel attached to the front of the door 6.

The damper device 17 includes a baffle plate 18
In addition to the above, as shown in FIG.
A first gear 26 and a first cam 27 attached to the rotating shaft 25 of the AC motor 24; a second gear 28 meshing with the first gear; and a second cam 29 provided on the second gear 28. And a pin 30 for opening or closing the baffle plate 18 with the rotation of the second cam 29.
A swing arm 31 that reciprocates in the left-right direction with the rotation of the first cam 27, and a reed switch 32 as a switch that performs an opening or closing operation in accordance with the reciprocation of the swing arm.

The first cam 27 has, on its peripheral surface, a large arc surface 33 far from the center thereof, a small arc surface 34 near the center, and two step surfaces 35 serving as boundaries between the large and small arc surfaces. is there. The second cam 29 has a high portion surface 36, a low portion surface 37, and a slope 38 serving as a boundary between the high and low portions on a surface where one end of the pin 30 contacts. When the baffle plate 18 is in contact with the lower portion surface, the baffle plate 18 is in the closing operation (that is, in the closed position), and
, The baffle plate 18 is maintained in the open operation (ie, the open position). When the pin 30 moves from the low surface 37 to the high surface 36 through the slope 38 or vice versa, the baffle plate 18 moves from the closed position to the open position or from the open position to the closed position.

The swing arm 31 receives a shaft (not shown) and serves as a fulcrum for rotation of the arm, a projection 40 whose tip contacts the peripheral surface of the first cam 27, and one surface is formed on the reed switch 32. And a magnet 42 buried in the widened portion 41 in contact therewith. When the projection 40 is in contact with the small arc surface 34 of the first cam 27 as shown in FIGS.
And the first cam 2 as shown in FIGS.
7, the projection is in contact with the large arc surface 33.
1 contacts the reed switch 32.

The reed switch 32 includes a pair of contact pieces 4.
When the swing arm 31 is in contact with the reed switch 32 as shown in FIGS. 2B and 2C, the magnetic force of the magnet 42 causes the two contact pieces 43, 44 of the reed switch 32 to come into contact with each other. Will be turned on.

As shown in FIG. 6, reference numeral 45 denotes the baffle plate 1.
8 is a sealing member also provided as a cushioning member provided on the back surface of the baffle plate 18 and made of foamed polyethylene or the like.
Alleviates the impact when closing. Reference numeral 46 denotes a resin case that covers the front surface of the heat insulating cover 19, and cool air outlets 47 are formed on both left and right sides.

FIG. 3 is an electric circuit diagram including the control device of the present invention. Reference numeral 50 denotes a microcomputer as a control device, the input terminal of which is connected to the output terminal of a full-wave rectifier 51. An AC power supply 52 is connected to an input terminal of the wave rectifier 51.

The AC motor 24 is connected to an AC power supply via a contact point Ra of a relay Ry described later, and the reed switch 32 is connected to an output terminal of a full-wave rectifier 51 by forming a series circuit with a resistor R. ing. A signal line 53 has one end connected to a midpoint a between the reed switch 32 and the resistor R, and the other end connected to a position detection unit 56 (described later) of the microcomputer 50. When the reed switch 32 is closed (that is, turned on), a high-level signal (hereinafter, referred to as high-level H) is output to the position detection unit 56. Ry is a relay including a coil Rc excited by the high level H from the microcomputer 50 and a contact point Ra, and serves as a switch for turning on and off the AC motor 24.

The microcomputer 50 includes a freezing room temperature control unit 54 that receives an output signal of a freezing room temperature sensor FS for detecting the temperature of the freezing room F as an input signal, and a refrigerating room temperature sensor RS that detects the temperature of the refrigerating room R. When the refrigerating room temperature control unit 55 having an output signal as an input signal and the reed switch 32 is in an ON state (that is, when the projection 40 of the swing arm is
7 is in contact with the large arc surface 33 of the swing arm 7 and is in the off state (ie, the projection 4 of the swing arm).
When a low level signal (hereinafter referred to as a low level L) is output at a time when 0 is in contact with the small arc surface 34 of the first cam 27, a position detecting section 56 for detecting the position of the cam, and the position detecting section 56 is high. When switching from level H to low level L (or vice versa), a timer section 57 that outputs a clock path for a fixed time, and the reed switch 32 is turned on when the accumulation (or subtraction) of clock pulses from the timer section 57 is completed. State or off state (that is, the position detection unit 5
6 is a high level H or a low level L), and the output of the determination unit 58 is input, and the determination unit 58 is used to appropriately control the energization time of the AC motor 24 in accordance with the power supply frequency. The storage unit 59 stores data relating to the energization time corresponding to the result determined in step (1), that is, the power supply frequency (either one of 50 Hz or 60 Hz). The microcomputer 50 may control the operation of the AC motor 24 of the damper device 17 after detecting the power supply frequency (that is, the energizing time) based on the data stored in the storage unit 59 and the output of the refrigerated room temperature control unit 55.

The freezing room temperature control section 54 and the refrigerated room temperature control section 55 have an A / D conversion section, a comparison section and a temperature setting section, respectively. The temperature (measured value) detected by the sensors FS and RS corresponding to both control units is A /
The data is D-converted and compared with the upper limit set temperature and the lower limit set temperature in the respective comparison units to control the operation of the compressor and the drive of the AC motor.

For example, a microcomputer 50 as a control device
Stops the compressor 20 when the measured temperature of the freezer compartment F reaches the lower limit set temperature of the freezer compartment, while operating the compressor 20 when the measured temperature of the freezer compartment F reaches the upper limit set temperature of the freezer compartment. Thus, the temperature of the freezer compartment F is controlled to an intermediate temperature between the upper limit set temperature and the lower limit set temperature of the freezer compartment.

When the measured temperature of the refrigerator compartment R reaches the upper limit set temperature of the refrigerator compartment, the microcomputer 50 sets a relay Ry.
By energizing the one to open the baffle plate 18 by driving the AC motor 24 to close the contact Ra excites the coil Rc, performed the closing operation when the measured temperature of the refrigerating chamber R reaches the lower limit set temperature of the refrigerating compartment Energize relay Ry
Then, the contact Ra is closed and the AC motor 24 is driven to close the baffle plate 18. By controlling the opening and closing of the baffle plate 18, the temperature of the refrigerator compartment R is controlled to an intermediate temperature between the upper limit set temperature and the lower limit set temperature of the refrigerator compartment.

[0022]

In particular, if the power supply time to the AC motor 24 by the control device (microcomputer) 50 after the power supply frequency is detected is set to be different according to the detected frequency, the power supply frequency changes. Also, it is possible to provide a so-called self-contained power supply frequency detecting device that can detect the power supply frequency when the power is turned on and use the detection result to control the AC motor after the detection.

When an AC power supply is turned on to the electric circuit of FIG. 3 (that is, when a refrigerator is installed and an outlet is inserted, and when the power supply is restored after a power failure), the relay Ry is energized by a program of the microcomputer 50, that is, initial setting. The AC motor 24 is also driven when it is operated.

Next, the operation of detecting the power supply frequency will be described with reference to FIG.
This will be briefly described with reference to FIGS. When the AC power is turned on (that is, when the refrigerator is installed and the outlet is plugged in and when the power is restored after the power failure), the microcomputer 50
Is initialized, the coil Rc of the relay Ry is excited, its contact Ra is closed, and the AC motor 24 is driven to
The cam 27 and the second cam 29 rotate.

Here, for example, when the projection 40 of the swing arm 31 is in contact with the small arc surface 34 of the first cam 27 as shown in FIG. 2A, the reed switch 32 is turned off and the position detector 56 is turned off. When the projection 40 of the swing arm 31 is in contact with the large arc surface 33 of the first cam 27, as shown in FIG.
Is in the ON state, the position detector 56 outputs a high level H. When the output of the position detector 56 shifts from the high level H to the low level L (or reverse shift), the count of the timer unit 57 starts. Is done.

Then, as shown in FIG.
Considering that the time required for one cycle of the first cam 27 at 0 Hz is 18 seconds, and the time required for one cycle of the first cam 27 when the power supply frequency is 60 Hz is 15 seconds, If, for example, 16.5 seconds, which is an intermediate value between the two frequencies, is set as the reference value as the count end time of the timer unit 57, the position detection unit when the time (16.5 seconds) of the reference value has elapsed in the timer unit 57. The determination unit 58 determines whether the output of the signal 56 is at a high level H or a low level L, so that the power supply frequency is 50 Hz for a high level H and 60 Hz for a low level L. It can be detected accurately.

The power supply frequency can also be detected by operating the damper device 17 at least one cycle when the power is turned on and measuring the time of this one cycle.
That is, since the time required for the baffle plate 18 of the damper device 17 to perform one cycle of operation changes according to the power supply frequency, for example, the time required when the power supply frequency is 50 Hz is used as a reference. The power supply frequency can be detected by examining (i.e., comparing) the length relationship between the two.

In other words, if the measured time is shorter than the reference time, the power supply frequency is 60 Hertz, and if the measured time is equal to or longer than the reference time, the power supply frequency is 50 Hertz. Since the drive time of the AC motor 24 is controlled by the control device (microcomputer) 50 in accordance with the detected power supply frequency, a so-called self-operation that performs both the operation of detecting the power supply frequency and the control operation of the damper device 17 after the detection is performed. A complete power supply frequency detection device can be provided.

In any case, no waveform shaping circuit is required.

[0031]

According to the present invention, the AC motor is rotated in synchronization with the power supply frequency, so that the control device controls the power supply when the power is turned on (that is, when the refrigerator is installed and the outlet is inserted, and when the power is restored after the power failure). The power supply frequency is detected by operating the damper device for at least one cycle and measuring the time of this one cycle.

The time required for one cycle of operation of the baffle plate of the damper device changes according to the power supply frequency.
For example, the power supply frequency can be detected by examining (i.e., comparing) the length of time measured here with the time required when the power supply frequency is 50 Hz as a reference. That is, if the measured time is shorter than the reference time, the power supply frequency is 60 Hertz, and if the measured time is equal to or longer than the reference time, the power supply frequency is 50 Hertz.

The driving time of the AC motor is controlled by the control device in accordance with the detected power supply frequency. Therefore, a so-called self-contained type which performs both the operation of detecting the power supply frequency and the control operation of the damper device after detection. A power supply frequency detection device can be provided. In this case, a waveform shaping circuit is unnecessary.

[Brief description of the drawings]

FIG. 1 is a perspective view of an essential part of a damper device for a refrigerator according to the present invention.

FIGS. 2A to 2D are operation explanatory diagrams for explaining a positional relationship among a first cam, an arm, and switch means.

FIG. 3 is an electric circuit diagram including the control device of the present invention.

FIG. 4 is a time chart illustrating a frequency detection operation in the control device.

FIG. 5 is a longitudinal sectional view of the refrigerator of the present invention.

FIG. 6 is a horizontal sectional view taken along line AA of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigerator 17 Damper device 18 Baffle board 24 AC motor 25 Damper device 32 Switch means 50 Control device (microcomputer)

Claims (1)

(57) [Claims] 1. An AC motor that rotates in synchronization with a power supply frequency, a gear, a cam, and a pin that convert the rotational motion of the motor into a reciprocating motion. A baffle plate for adjusting a flow rate of the cool air, switch means for outputting a signal when the cam changes from one state to another state to detect a rotational position of the cam, and provided so as to reciprocate with the rotation of the cam. A refrigerator having a damper device having an arm for turning on and off the switch means, and a control device for opening and closing a baffle plate of the damper device to control the supply of cool air to the storage room. When the power of the refrigerator is turned on, the control device moves the baffle plate by reciprocating pins.
Ri by driving the AC motor so as to open and close operation is at least one cycle operation of the damper device, detecting the power frequency required to control the energizing time to said AC motor by measuring the time of one cycle A power supply frequency detection device for a refrigerator.