JPS6033226B2 - refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a damper that opens and closes a cold air outlet to a refrigerator compartment, and particularly relates to an invention in which a holding solenoid is used to drive the damper, and the damper is operated instantaneously. It is something.

A damper thermostat for adjusting the amount of cold air installed in a commercially available refrigerator extracts the change in the state of the gas sealed in the heat-sensitive tube as expansion and contraction of the bellows, and transfers this via an operating lever etc. to the blade of the damper ( It was used to open and close dampers to adjust the amount of cold air.

In dampers equipped with this type of gas thermostat, in order to prevent malfunctions, a heater is usually installed in another part (thermo body) so that the temperature of the thermosensitive part is the lowest. There is.

This heater for preventing malfunction is continuously energized because it is provided so that the thermostat is always set higher than the thermosensitive tube section. Therefore, even if the heater capacity is about 1 to 2 W, it will not only be a very large number if accumulated over a period of one month or a year, but also because the thermostat is installed in or near the refrigerator room. The malfunction prevention heater becomes a heat load on the refrigerator compartment, going against recent efforts to save power. The present invention discontinues the temperature control method (gas thermometer) that goes against the above-mentioned power saving and controls the temperature electrically, and in order to save power, an AC control element is installed in the AC power line and cold air is sent to the refrigerator compartment. A self-holding solenoid that drives a damper that opens and closes the discharge port is connected in series, and a positive or negative pulse is applied at a certain period according to the signal from the temperature sensor and the timing is matched to the phase of the AC line. The above-mentioned self-holding solenoid is provided to open and close the damper, and also to control the ON/OFF of the compressor and the opening/closing of the freezer compartment door and the refrigerator compartment door. The details of the present invention will be explained below with reference to an embodiment shown in the drawings. Reference numeral 1 denotes a refrigerator body, and the refrigerator body 1 has a freezer compartment 2 and a refrigerator compartment 3 inside.

Reference numeral 4 indicates an outlet through which the cold air that has passed through the cooler 5 is forcibly discharged into the refrigerator compartment.

6 is a damper attached to the outlet.

As shown in FIG. 2 in detail, this damper 6 includes a holding solenoid 8 equipped with a permanent magnet 7, an operating rod 10 that moves in conjunction with the movement of a movable iron 09 of the solenoid, and a movable iron i.
When D9 is not attracted, the coil spring 13a that keeps the operating lever 10 at that position (the position where the blade 11 keeps the duct 12 open) against the magnetizing force of the permanent magnet 7 and the movable iron core 9 are attracted. It is composed of a second coil spring 13b and the like to keep the duct 12 closed by the blade 11. Figure 3 shows a circuit that allows this solenoid 8 to operate on an AC line without using a transformer or the like.
4 and 5 show voltage waveforms at each point on the circuit. In FIG. 3, a sine wave as shown in FIGS. 4a and 5a is supplied from the AC power supply 14, and is input to the primary side of the DC power supply section 15. From the secondary side of the DC power supply section 15,
As shown in FIG. 4b, negative voltages Vcc, Vcc2 are output, and one end is connected to one side of the AC line to form a common line. Vcc is a stabilized voltage and is connected to the resistor 31, the oscillation circuit 16, and each C-MOS logic element. Vcc2 is a voltage even lower than Vcc, and is connected to the gate G of the AC control element 25 via the current limiting resistor 27 and the transistor 23. V
cc, , Vcc2, a large pulse current is used as the gate current of the AC control element 25.
Even if Vcc2 fluctuates due to the flow into cc2,
Vcc can maintain a constant voltage and perform stable control operations. In the oscillator 16, as shown in FIG.
As shown in FIG. 3, a pulse voltage having an operation time t is generated at an arbitrary period T and is input to the NOR gate 39.

All logic elements are C-MOSC, and the circuit configuration takes full advantage of its low power consumption, input protection circuit, output characteristics that swing close to the power supply voltage, and threshold voltage characteristics of approximately 1'2 of the power supply voltage. ing. N
The other input of the OR gate 39 is connected to the inverters 32 and 3.
3. It is connected to a one-shot multipipulator formed by an AND gate 36, a resistor 34, and a capacitor 35.

FIG. 5 shows voltage waveforms illustrating the operation of this one-shot multipipulator. The switch 45 is turned off when the doors of the freezer compartment and refrigerator compartment are opened, and stops the fan 42 for circulating cold air.

The switch 44 moves in conjunction with the door switch 45, and turns OFF when the door is open, preventing power from being supplied to the solenoid 8, and prevents the operation of the damper 6 when the door is open and does not have sufficient sound insulation. Prevents the sound from being heard.

The switch 41 is a switch that controls the compressor 43 and the fan 42, and the switch 40 is adapted to move in conjunction with this control switch 41.

When the compressor is OFF, the switch 40 is also OFF, a low level voltage is applied to the input of the inverter 32 through the pull-down resistor 31, and the output of the inverter 33 and the AND gate 36 are also low level. becomes.

On the other hand, the output of the inverter 32 becomes high level and the NAND
It is input to gate 46. For this reason, NAND gate 4
The output of diode 3 has the waveform d in Figure 4.
8 to the EX-NOR gate 21.
Next, when the compressor 43 is turned on from OFF, the switch 40 is also turned on, and the input of the inverter 32 and the output of the inverter 33 go from low to high as shown in FIG. 5b. Note that three capacitors are inserted to prevent chattering. The output of the inverter 32 changes from / to low as shown in Fig. 5c, but the potential at the connection point between the resistor 34 and the capacitor 35 cannot follow it immediately and changes as shown in Fig. 5d. do. Therefore, the AND gate 36 inputting this potential has a threshold voltage VTH
Up to that point, it is accepted as a high level. From this,
At the output of the AND gate 36, a one-shot pulse t' shown in FIG. This one-shot pulse t' has the same function as the operating time t obtained by the oscillation section 16, and maintains the connection point between the sensor 17 and the variable resistor 18 at a high level for the time t' through the diode 37. do. The output of the NOR gate 39 is normally supplied with the pulse voltage from the oscillator 16 as shown in FIG.
A pulse voltage that is at a low level only during the operating time t is obtained at intervals of period T, and the compressor is turned off.
At the time when it turns ON', a single pulse voltage is obtained which is at a low level only during t' as shown in FIG. From the AC line, there is a resistor 2 for detecting the phase of the lightning line.
0 is connected and input to the buffer 46 for waveform shaping and the EX-NOR gate 21. diode 1
9 is EX-NOR at points other than operating times t and t'.
The input of gate 21 and buffer 46 are maintained at high level. The output of the buffer 46 is connected to EX-N via a resistor 47.
It is input to the other side of the OR gate 21. The waveform inputted from the resistor 20 is reduced to a waveform as shown in FIG. 4e by the action of the diode 19 and the input protection circuit of the C-MOSIC. The blade 11 is opened and closed by supplying DC pulse voltage to the solenoid 8, and the accompanying temperature return signal is detected by the sensor 17, and is connected to the resistor 22 from the connection point with the variable resistor 18 connected in series. is input to the terminal to which the resistor 47 of the EX-NOR gate 21 is connected.

The variable resistor 18 is used to set the operating level with respect to the threshold voltage of the EX-NOR gate 21 serving as a reference, and arbitrarily sets the operating temperature. As is well known, the EX-NOR gate is a coincidence gate, and the output becomes high level only when the inputs match, regardless of whether the inputs are at high level or low level. Therefore, at times other than operating times t and t', BX-N
Both inputs of the OR gate 21 are at high level, and the output is also at high level. On the other hand, operating time t, t''
In this case, when the input via the resistor 22 from the connection point between the sensor 17 and the variable resistor 18 is below the threshold voltage of the EX-NOR gate 21, the output of the EX-NOR gate 21 as shown in FIG. On the other hand, when the voltage exceeds the threshold voltage, a waveform as shown in Fig. 4g is output. Here, assuming that the voltage inputted from the detection section via the resistor 22 almost matches the threshold voltage, it is conceivable that a slight change in the input signal may cause unstable operation.

In such cases, a Schmitt circuit or the like is generally adopted, but in this circuit, the input from the detection section is input by the resistor 47 and the resistor 22 at the output of the buffer 46 which outputs pulses in synchronization with the phase of the AC line. Apply a bias to the voltage,
We explored a method in which the drive pulse from the EX-NOR gate 21 is not output in an unstable operating range. The manner in which the bias voltage is applied to the input voltage during the operating time t is shown in equivalent circuits as shown in FIGS. 6 and 7.

FIG. 6 shows the circuit when the buffer 46 detecting the phase signal of the AC line goes to high level, and FIG. 7 shows the circuit when it goes to low level.

In FIG. 6, during the operating time t, the output of the buffer 46 is at a high level, so that the resistor 47 and the resistor 22, which are connected in series, are connected in parallel with the sensor 17.

In this state, the voltage at the connection point of resistor 47 and resistor 22 is EX-
Since it is input to the NOR gate 21, it is naturally input at a higher voltage than the divided voltage when configured only with the sensor 17 and the variable resistor 18.

In FIG. 7, since the output of the buffer 46 is at a low level, the resistor 47 and the resistor 22 connected in series are connected in parallel with the variable resistor 18.

In this state, the voltage at the connection point of resistor 47 and resistor 22 is EX-
Since it is input to the NOR gate 21, it is naturally comprised of only the sensor 17 and the variable resistor 18, and is input at a voltage lower than the current divided voltage. This is how to apply bias. FIG. 8 shows the specific operation of this system during the operation time t. 8a to 8g sequentially show the process in which the input voltage level changes from high level to low level.

Note that the input voltage waveform when bias is applied by this method is shown as Vin, the detection waveform of the electric circuit phase is shown as V0, and the output waveform of the EX-NOR gate 21 is shown as Vout. In the diagram of the input voltage waveform Vin, the voltage level indicated by a dashed line is the threshold voltage VTH of the EX-NOR gate 21, which serves as a reference for level determination. FIG. 8a shows the input voltage Vjn
EX-NO when is higher than the threshold voltage VTH
As the output of the R gate 21, a waveform having the same pattern as the detection waveform of the electric circuit phase is outputted.

FIG. 8b shows a state in which the input voltage Vin approaches the reduced threshold voltage VTH, and even if the input voltage Vin is shifted by the output of the buffer 46, it is still higher than the threshold voltage VTH. In FIG. 8c, when the input voltage Vin further decreases and the output of the buffer 46 shifts to low level, the threshold voltage VT
This shows a state where the temperature is below H.

At this time, the output waveform Vout of the EX-NOR gate 21 is kept at a high level. FIGS. 8d and 8e also show a state in which the input voltage is further reduced.

FIG. 8f shows a state in which the input voltage Vin further decreases and becomes below the threshold voltage VTH both when the output of the buffer 46 shifts to a low level and when it shifts to a high level.

At this time, the output Vout of the EX-NOR gate 21 outputs a waveform of a pattern that is an inversion of the detection waveform of the hazy road phase during the operation time t. From the above explanation, the pulse that was output when the lightning track phase detection signal was at low level 4, after a period of no pulse output, turned around and began to output a pulse when it was at low level. Although FIG. 8 shows a process in which the input voltage Vjn wants to change from high level to low level, changing from low level to high level is a completely opposite operation.

When the output of the EX-NOR gate 21 becomes low level, the base of the transistor 23 is pulled to Vcc via the resistor 24, and the transistor 23 is turned on. transistor 23
When becomes OM, the terminals T, gate G, of the AC control element 25 are connected from the DC power supply 15 via the common line of the AC circuit
A gate trigger current flows through the transistor 23 and the gate current limiting resistor 27 to the Vcc2 line, and the terminals T and T2 of the AC control element 25 become conductive, and the solenoid 8
is energized. When the input connected to the resistor 22 of the EX-NOR gate 21 is at a low level during operation time t, the solenoid 8 has a diode 28 and a current limiting resistor 26.
Through the voltage shown in Figure 4 h is applied and pulls the movable iron D9.
Move it to the side to close the blade 11. In other words, when the compressor 43 is ON and the temperature of the refrigerator compartment 3 is low (sensor 1
7) or when the compressor 43 is OFF (switch 40 is OFF), the damper 6 is closed. When the compressor 43 is OFF, the cold air passage is closed by closing the damper 6, and the air in the refrigerator compartment 3 flows back into the cold air passage.
This prevents dew from forming in the cold air passage. on the other hand,
When the input to which the resistor 22 of the EX-NOR gate 21 is connected is at a high level during operating times t and t', the current is supplied to the solenoid 8 through the current limiting resistors 26 and 29 as shown in FIG.
, a voltage g in FIG. 5 is applied, the movable iron core 9 is moved to the P female h side, and the blade 11 is opened. In other words, when the compressor 43 is ON and the temperature of the refrigerator compartment 3 is high (sensor 1 7
(the resistance value of the compressor 43 is small) or the compressor 43 is
When the switch 40 changes from OFF to ON (the switch 40 changes from OFF to OFF)
N), the damper 6 is opened and cold air flows into the refrigerator compartment 3. Note that the diode 28 has a suction (
It is inserted to support the characteristics of the self-holding solenoid 8, which requires a large current during PMI. Temperature control is also possible with this control method, which provides a state in which the pulses shown in Fig. 8c, d, and e are not output by forcibly opening the damper 6 once the compressor 43 is energized. I can do it. As explained above, the present invention connects an AC control element and a holding solenoid that drives a damper that opens and closes a cold air outlet to a refrigerator compartment in series to a DC line, and also connects an AC control element in series to a DC line in response to a signal from a temperature sensor. Since a positive or negative pulse is applied to the above-mentioned holding type solenoid at a certain period in time with the phase of the damper, the power consumed to open and close the damper is almost nil. Of course, it is possible to operate a solenoid that should be operated with direct current using a conventional alternating current element, which is advantageous in terms of cost. Accordingly, the conventional constantly energized type heater for preventing accidental operation can be eliminated.

In addition, when the compressor is stopped, the damper is closed to prevent frost from forming on the inner wall of the cold air passage, and when the compressor is energized, a non-operating area is provided for stable temperature control. To assist in this temperature control, the damper is forcibly closed once the compressor is energized.

On the other hand, when the door is open, the solenoid circuit is closed, the damper stops operating, and unnecessary noise is prevented. Through this series of control methods, a temperature control device suitable for actual use can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the main parts of a refrigerator equipped with the present invention, FIG. 2 is a detailed diagram of a damper section that constitutes a part of this device, FIG. 3 is a control circuit equipped with the present invention, and FIG. 4 , FIG. 5 shows voltage waveforms at each point on the circuit of FIG. 3, FIGS. 6 and 7 show partial equivalent circuits for explaining the circuit of FIG. 3, and FIG. 8 shows a partial equivalent circuit for explaining the circuit of FIG.
FIG. 7 is a diagram showing voltage waveforms for explaining the operations in FIGS. 6 and 7; 1... Refrigerator body, 2... Freezer compartment, 3
... Refrigerator room, 4 ... Air outlet, 5 ...
・Cooler, 6... Damper, 7... Permanent magnet, 8... Holding solenoid, 9...
...Movable iron core, 10...Operation rod, 11...
Blade, 12...Duct, 13...Coil spring, 14
... AC power supply, 15 ... DC power supply section,
16... Oscillation circuit, 17... Sensor, 18... Variable resistor, 19... Diode, 20... Resistor, 21...・・EX-NO
R gate, 22... Resistor, 23... Transistor, 24... Resistor, 25... AC control element, 26... Resistor, 27... ...Current limiting resistor, 28...Diode, 29...
・Resistance, 30... Capacitor, 31...
・Resistance, 32...isoverter, 33. ．．・・・．
・Inverter, 34... Resistor, 35...
・Capacitor, 36...AND gate, 37・
...Diode, 38...Diode, 39
...NOR gate, 40... switch, 41...
...Switch, 42...Fan, 43...Compressor, 44...Task switch, 45...Door switch, 46...
...NAND gate (buffer), 47...Resistance. Figure 3 Figure 2 Figure 4 Figure 6 Figure 7 Figure 5 Figure 8

Claims (1)

[Scope of Claims] 1. An AC control element and a self-holding solenoid that drives a damper that opens and closes a cold air outlet to a refrigerator compartment are connected in series to an AC line, and the AC line is controlled in response to a signal from a temperature sensor. A positive or negative pulse, timed to the phase of A refrigerator characterized in that the refrigerator is controlled by being associated with the refrigerator. 2. The refrigerator according to claim 1, further comprising a switch that blocks power supply to the solenoid when the refrigerator compartment door or the refrigerator compartment door is opened. 3. Claim 1, characterized in that the circuit is configured such that the damper is closed when the compressor is not operating, and the damper is forcibly opened when the compressor starts operating. Refrigerator as described.