JPS58198670A - Control system of temperature of refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a refrigerator, and relates to a temperature control system for a refrigerator in which the flow of refrigerant to a cooler is controlled by an electronic control circuit.

[Technical background of the invention and its problems]

In general, in a two-temperature refrigerator that has nine separate coolers in each of the freezer and refrigerator compartments, the coolers installed in the refrigerator compartment are exposed at the upper part of the interior of the refrigerator. many. In a refrigerator having such a structure, the flow of refrigerant to the cooler in the refrigerator compartment is controlled by an electronic circuit as described below.

That is, when the cooler 12) Il& is detected by a sensor and the cooler rises to the set temperature 11, a temporary memory element such as a flip-flop is set, and the inside of the refrigerator is cooled while refrigerant flows through the cooler. On the other hand, when the room temperature inside the refrigerator is detected by another sensor and the temperature drops to the set value, the temperature inside the refrigerator is reset by resetting the above-mentioned temporary storage element and stopping the supply of cool air to the cooler. It is configured to perform control.

However, in this case, for example, if the door of the refrigerator compartment is left open or if the door is left open for a long time, the temperature around the unit that detects the room temperature inside the refrigerator will not drop. There is a problem in that thick frost accumulates on the surface of the cooler because refrigerant is continuously supplied to the cooler for a long time and the cooler is operated under overload. In addition, in order to switch the flow of the compressor or refrigerant, 9 solenoid valves, etc.
The set of temporary storage elements may be switched due to the noise generated at F, and there is a risk of malfunction, so a protection circuit is required to prevent this malfunction. This circuit has drawbacks such as complexity and increased cost.

(9) Conventional refrigerators are equipped with solenoid valves that allow refrigerant to be selectively supplied to coolers provided independently in the freezer compartment and the refrigerator compartment. The opening and closing of this solenoid valve is controlled by the cooler temperature or air temperature in the refrigerator compartment. Therefore, even though the compressor, which is controlled to be turned off due to the temperature of the freezing compartment, is turned off, the solenoid valve may remain energized. For this reason, as a refrigerator that strives to save power, this state has the disadvantage of leading to wasteful power consumption. If the solenoid valve is turned off at the same time just because the compressor is turned off, the flow of refrigerant in the refrigeration cycle will not be stable, and this will have a negative effect on the refrigerator compartment.

[Purpose of the invention]

The present invention has been devised in view of the above drawbacks, and an object of the invention is to prevent the refrigerant from flowing backward from the freezer compartment to the refrigerator compartment by maintaining stable operation of the refrigeration cycle. The objective is to prevent the cooler from becoming overcooled.

[Summary of the invention]

According to the present invention, when the solenoid valve is in an excited state and the compressor is turned off, the solenoid valve is activated for a predetermined period of time regardless of the temperature of the refrigerator compartment by the signal of the compressor restart prevention titer, which is activated at the same time as the compressor is turned off. After maintaining the energized state, the energized state of the solenoid valve is released.

〔Effect of the invention〕

By controlling the temperature of the refrigerator as described above, the refrigerant from the freezer compartment is prevented from flowing back into the cooler in the refrigerator compartment. In addition to preventing the temperature of the freezer compartment from rising in a short period of time, it is possible to maintain the Compressuna's 0FF-ON cycle in the optimal state, and furthermore, the compressor can be
When the temperature reaches K, the solenoid valve turns OFF after the set time has elapsed, resulting in extremely low power consumption.The time the solenoid valve turns OFF is set using the restart prevention timer, which simplifies the circuit configuration and reduces the number of parts. Since the amount of water is reduced, the above-mentioned effects can be achieved at low cost.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view of a schematic overall configuration of an example of a refrigerator equipped with a temperature control device for a refrigerator according to the present invention. 3, the refrigerator main body 1 is composed of a freezing compartment 2 and a refrigerating compartment 302. A $1 cooler 4 is attached to the inner peripheral wall of the freezer compartment 2, and the inside of the freezer compartment 2 is cooled by this cooler 4. Inside the freezer compartment 2, a Q2 star 5 that detects the indoor air temperature is arranged, and based on the temperature detected by the first thermistor 5, a compressor 6 provided in the machine compartment 20 is controlled to turn on and off. ing. On the other hand, at the back of the upper part of the refrigerator 3, a ninth second cooler 7 is arranged so as to extend into the room. A second thermistor 8 is installed in the second cooler 7 to detect the temperature of the cooler 7, and a third thermistor 9 is placed near the thermistor 8 to detect the air temperature itt in the refrigerator 11B. has been done. These @2. Based on the temperature detected by the third thermistor, the solenoid valve 10
to control the flow of refrigerant to the first and second coolers 4.7. The freezer li2 and the refrigerator compartment 3 are provided with hinges 7'jfi 12 and 13, which can be freely opened and closed by a hinge IIK. Said machine i! 20 is provided with a control s14 comprising a control circuit, and this control 1i114 performs a predetermined operation to be described later in response to a signal from the operating section 15 comprising the door 12 of the freezer compartment 2. . Number 16 is the refrigeration control switch, and number 17 is the refrigeration control switch. F[ffl control switches 16 and 17 are provided on the operating section 1s. The cooling temperatures of the freezer compartment 2 and the refrigerator compartment 3 are set using these switches. Previously, the solenoid valve 10 has a housing 102 K into which the valve body 101 is slidably inserted, and three openings 10.
10b, i, and Oc. This valve body 101 is
When it stops at a position where the tenth mouth 10m and the second mouth 10b communicate with each other and the magnetic coil 103 is excited, the inside of the pufferfish 102 is slid so that the first mouth 10m and the third mouth 10c communicate with each other. When the excitation state of this coil is released, the valve body 101 returns to the position where the first port 10a and the second port 10b communicate with each other due to the rear force of the spring 104 and remains stationary. The electromagnetic valve 1o has one end connected to the first capillary tube 18□ from the first port 10m.The other end is connected to one end of the condenser 19 via the piping 6b, and the other end is connected to the capillary tube 18 through the piping 6b. The third port 10 is connected to the refrigerant discharge side of the compressor 6.
c is connected to one end of the second capillary tube 21,
The other end is connected to the inlet 11 of the tenth cooler 4 via a pipe 6c.

Further, the 20th port 10b is connected to the second cooling @7 via the pipe 6d.
The refrigerant outflow side of this cooler 7 and the refrigerant inflow side of the first cooler 4 are connected by a pipe 6. And said first cooling! The outflow equipment of wI, 4 and the inflow side of the compressor 6 are connected by a pipe 6f.

The refrigerator of the present invention having the above-described configuration has the control unit 14 and the operation unit 15 configured to have t[i
Control of the al road configuration - Controlled by the road. FIG. 2 is a block diagram showing an example of a temperature control device for a refrigerator according to the present invention.

That is, the operation section 15 includes a control switch 16.
．． 17C) 9th LID (Light 1mltlng Diode) for freezing room temperature display that does not indicate mKml and LED for displaying 11th and quick freezing IJD
A switch is provided to reset the start and end of defrosting. Block 30 in FIG.
This is an input/output block for the above-mentioned switch and LED. That is, 31 to 33 are LIDs for displaying temperature in the freezer,
The temperature of the freezer 112 is displayed. 34 is an LED that is displayed when defrosting the freezer compartment 2, and 35 is an LED for displaying rapid freezing. . 9DS is an interrupt switch for starting defrosting of the freezer compartment 2, and DR is an interrupt switch for interrupting the defrosting midway. Furthermore, S8 is a rounded switch that starts rapid freezing, and A2B is a rounded switch that interrupts this midway. The volume volume 37.38 is linked to the control switch 16.17K provided for setting the temperature of the freezer compartment 2 and refrigerator 113 mentioned above, and the signals from these switches Da, DB and volume 37.38 are the same as those mentioned above. Supplied to the nermo and drive block 40. A block 30 provided on these operation sections and a nine block 40 provided on the control section 14
A signal line 39 connecting between the two is connected through the hinge 11. On the other hand, the thermostat and drive block 40 includes a set of temperature detection circuits 41, 42, and 43 connected in series and consisting of a nine-Z star and a resistor, a relay coil 44 for turning the compressor 6 on and off, and a solenoid valve for turning on and off the compressor 6. A relay coil 45 for turning off the defrosting heater and a relay coil 46 for turning the defrosting heater on and off are connected. The thermistor 9 is connected to the temperature detection circuit 41 and is placed in the freezer compartment 2, and corresponds to thermistor 5 of the Kyuden 1, and is connected to the temperature detection circuit 421.
The thermistors connected to P and 43 may be placed in the refrigerator compartment 3 and correspond to the second and third thermistors 8 and 9. The block 40 and the block 30 having such external circuits are provided on the control unit 14 side, and the energizing circuit 11 circuit 5
0, the commercial power supply OA 0100 (V) is converted to #iD, Ct2 (V) electricity 11 to the operation unit and temperature detection unit, and is applied to the relay coil, where it is converted to Cl2 (V) electricity 11 and supplied. FIG. 3 is a schematic diagram of the relay in FIG. 2, and the same parts are designated by the same reference numerals, and the explanation thereof will be omitted. That is, 6
0 is a 100 (V) outlet, 61 is a defrost relay contact,
62 is a defrosting heater, 63 is a temperature fuse, 64 is an electromagnetic relay contact, 65 is a compressor relay contact, 66 is an operating section 15. This is a control circuit including a control $14.

FIG. 4 shows the refrigerant O according to the refrigerator temperature control device of the present invention.
FIG. 2 is a circuit diagram showing an embodiment of means for controlling #l error.

That is, by switching the solenoid valve 10 and controlling ON/OFF of the compressor 6, this circuit controls the flow of paper and refrigerant to control the temperature. The operation of the circuit controlling the electromagnetic valve 10 is prioritized such that the defrosting operation is given top priority, followed by the rapid freezing operation and then the normal temperature control operation using a thermistor. That is, the defrosting start switch D8 is connected to the set terminal of the flip-flop 71, and the defrosting interruption switch DB is connected to the reset terminal of the flip-flop 71. The Q terminal of this flip-flop 71 is connected to one of two NOR gates 72, and the signal output of this NOR gate 72 is supplied to the base of a transistor 74 via a resistor 73, and the transistor 74 is connected to 0N-01i'P L, I'm here. An electromagnetic relay coil 45 is connected to the collector side of this transistor 74, and the coil 45 is energized.
As a result, the relay contact 64 is turned on and the solenoid valve 10 is driven. The output signal of another two-person NOR gate 75 is supplied to the other input terminal of the NOR gate 72. One input terminal of this NOR gate 75 is connected to the Q terminal of a 7-lip-flop circuit 76 for controlling rapid freezing.

A quick freezing start switch A88 is connected to the set terminal of this flip-flop 76, and a quick freezing interrupt switch A8R is connected to the reset terminal.

Further, the signal output of a first control circuit 77 for detecting the temperature of the second cooler 7 is supplied to the other terminal of the two-man powered Noah gate 75 via Noah gates 67 and 68. Furthermore, the signal output of the first control circuit 770 sets the flip-flop 122, and its Q terminal output is supplied to the other input terminal of the NOR gate 67. The first control circuit 77 converts the surface temperature of the second cooling s7 from the temperature detection circuit 43 into a voltage using the thermistor 8 at the inverting terminal of the comparator 78. This converted voltage V is then supplied. On the other hand, the non-inverting terminal of the comparator 78 has a resistor 79 and 800 which form a bridge circuit with the temperature detection circuit 43, and a divided voltage;
A voltage output of a predetermined level is supplied to the NOR gate 75 via the resistor 81 compared to the voltage V supplied to the inverting terminal. 9. This comparator 78 can be constructed by connecting a series circuit of a resistor 82 and a diode 83 in parallel to a non-inverting terminal and a series circuit of a resistor 81, so that the comparator 78 can be operated at different temperature level axes and - as shown in FIG. It has a hysteresis loop in which the voltage output is reversed. That is, when the relationship between the voltages supplied to the comparator 78 is Vm>Vt, the comparator 78 outputs a low voltage. Therefore, a current loop is formed that flows from the power supply V to the resistor 79, the diode 82, the resistor 81, and the comparator 78. The voltage V supplied to this rounded non-inverting terminal is V
, > V, even if the relationship Vm<Vt, the voltage output supplied to the non-inverting terminal appears lower than it was at the beginning, so the comparator 78 output maintains a low voltage. And V Tobi < V
, the output of the comparator 78 is inverted and becomes a high level voltage output. As is clear from this, the output of the first control circuit 77 is inverted at 92 different temperature levels.

The 20th control path 8 is connected to the inverting terminal of the magnifier/parator 78.
A signal voltage output from 5 is provided. This second control circuit 85 has a comparator 84, and a non-inverting terminal of this comparator 84 has a cooling armpit! A voltage output v1 which is thermoelectrically converted by the thermistor 9 is supplied from the temperature detection circuit 42 which detects the air temperature inside the air conditioner 3. On the other hand, the inverting terminal of the converter 84 is supplied with the resistor 86 forming a bridge circuit with the temperature detection circuit 43 and the divided voltage VIIR of the polyurethane 38 which is set for setting the R room temperature.
A voltage output V, which is at a predetermined level compared to V supplied to the non-inverting terminal, is supplied to the inverting terminal of the comparator 78 via a resistor 88 and a diode 89. That is,
The relationship between the voltages supplied to the comparator 84 is η>vll
When this happens, the comparator 84 outputs a high level voltage.

Therefore, in this case, the diode 89 prevents the voltage output from the comparator 84 from being supplied to the first control circuit 77, so that the first control circuit 77 is not affected in any way. However, when the comparison voltage supplied to the comparator 84 has a relationship of η<V, R, the comparator 84 outputs a low level voltage. Therefore, the first control circuit 7
A diode 891C forward voltage is supplied from the diode 7, and a current flows to the comparator 84. ° At this time, the resistor 88 and the thermistor 8 are connected in series and the nine resistors 90 are connected in parallel, and the resistance becomes small, so the voltage output vl supplied to the inverting terminal of the comparator 78 is small (V,
When the condition is satisfied and the comparator 78 dies, the output of the comparator 78 is forcibly inverted.

The hysteresis loop star 8 shown in Fig. 5 is VN.
>V, the surface temperature of the second cooler 7 is set to +3.5C, and the condition that VI<MS is created when the surface temperature of the second cooler 7 is -300C. Set. And it was made possible to set the temperature of the thermostat 9 using the volume 3B.

Therefore, if the air temperature in the refrigerator compartment 3 reaches the temperature set by the volume 38 before the surface temperature of the second cooler 70 reaches 130CK, the air temperature in the refrigerator compartment 3 will be detected by the servo and star 9. priority is given to the air temperature, the output of the first control circuit 77 is forcibly inverted, and the
F is also forcibly switched, and the solenoid valve 10 switches the flow of refrigerant to control the temperature.

This is the 30th control circuit that controls ON-OFF' of the comparator 109a.
10, and the temperature of the freezer compartment 2 from the temperature detection circuit 41 is connected to the inverting terminal of this comparator.
This converted voltage is supplied as (2). On the other hand, a resistor 111.1 forming a bridge circuit with the temperature detection circuit 41 is connected to the non-inverting terminal of the converter 110.
A timer consisting of a NOR gate 113 and a monostable multivibrator outputs a voltage at a predetermined level by comparing it with the voltage set by the volume 37 of the 12 volume 37 and supplied with the 9 compressor OFF voltage vn and the voltage supplied to the inverting terminal. 114 through a resistor 115.

between the polyneme 37 and the resistor 112 and the resistor 115
A series circuit of a diode 116 and a resistor 117 is connected between the two. The output signal from the σ terminal of the timer 114 is the NOR gate 113 and the NOR gate) 118
is supplied to one input terminal. The output signal of NOR gate 113 controls ON/OFF of transistor 119 and controls energization of relay coil 1200. The output signal of the NOR gate 113 is supplied to the other input terminal of the NOR gate 1180, and the output signal of this gate 118 controls the opening and closing of the NOR gate 68, and
The output of resets flip-flop 122.

Hereinafter, the operation of the refrigerator temperature control device of the present invention will be explained. Here, nine comparators 84 are set in the second control circuit 85.
To invert the voltage output, adjust the volume 38,
The air temperature in the refrigerator compartment 3 was set to be inverted by 14C.

In an electronically controlled refrigerator, defrosting operation takes priority over money, so when switch D8tONK is turned on, slip-slip 71 is set, and a high-level signal output is obtained from the Q terminal. The NOR gate 72 is then inhibited and the transistor 74 is turned off. As a result, the relay coil 45 is not energized and the relay contact 64 is not kept OFF, so the electromagnetic filter 10m is not energized and the opening 10m of the solenoid valve 10 is not energized.
and 10b are stopped by the restoring force of the spring 104 at the position where the valve body 101 communicates with each other, but at the same time, although not shown, the compressor 6 is stopped and the flow of O refrigerant to the second cooler 7 is stopped. will be stopped. Then, when the defrosting of the refrigerator Ila 7 is completed and the defrosting release switch DB is pressed at a key point, the Q terminal of the 7 lip-flop 71 becomes a low-level signal output, and the defrosting is interrupted. In the refrigerant O flow, no refrigerant flows as shown by the broken line in FIG.

The next priority operation is rapid freezing, and when switch A8g is pressed, the compressor 6 (not shown) is turned on at the same time, the shift flip-flop 76 is set, the Q terminal becomes high level, and the Noah game) 75.72 is in the open state. Therefore,
Transistor 74 is turned on, and current flows through relay coil 45. Therefore, the contact 64 is turned on, and the electromagnetic force of this coil turns on the solenoid valve 10 due to the current flowing through the electromagnetic coil 103.
Stop at the position where b is connected. Come on, conbrella t
Refrigerant is supplied only to the first cooler 4 from the first cooler 4 through the solenoid valve 10, thereby cooling the freezer compartment 2. When the thermistor 5 placed in the freezer compartment 2 reaches the set temperature, the combrella? Stop 6. Although the present invention does not explain in detail including the circuit configuration, the 0N of the compressor 6
-OFF is controlled by a thermistor 5 installed in the freezer compartment 2. Therefore, the refrigerant flows only through the thread path indicated by the solid line indicated by ω) in FIG. During this time, the room temperature of the refrigerator compartment 3 rises.

When the quick freezing interrupt switch 88 is pressed, the 7-lip flop 76 is reset to the q terminal line μ-level. Therefore, the flow of the refrigerant when defrosting and slow cooling are not working is controlled by the output of the first control circuit 77.

Next, if the surface temperature of the second cooler 7 is 3.5C or higher, the temperature of the refrigerator compartment is also 3.5C or higher, so there is no frost on the surface of the 20th cooler @7. . At this time, the comparison voltage supplied to the second control circuit 85C) comparator 84 has the relationship vl>v■O, so as mentioned above, the output of the comparator 84 is at a high level, and the diode 89 is reverse biased. Therefore, the operation of the first control circuit 77 is not affected in the non-conducting state. On the other hand, the input provided to the first control circuit 77 and supplied to the nine comparator 78 has a -> horse relationship, so as is clear from FIG. 5, the input is at a low level. Therefore, a low level signal is supplied to the two-man powered NOR gate 67, and its output becomes high level, and one input signal of the NOR gate 68 becomes high level. On the other hand, the set temperature for turning on the compressor 6 of the thermistor 5 installed in the freezer compartment is -10C in terms of air temperature.
If the temperature at 1 OFF is -20C, now the freezer compartment @
When the temperature drops to 110 Ut, the stone, V, and V, IL
The relationship between converter 110 and the supplied input voltage is v
, ＞V! , R and IJ), the output of the comparator 110, and current flows into the comparator 110 from the power supply via the resistor 122 and 115. Therefore, the signal supplied to the NOR gate 113 is low, and the signal supplied from the timer 114 is also low, so the output becomes high level, the transistor 119 is turned on, the relay coil 120 is energized, the contact 65 is turned on, and the compressor 6 turns on. Noah game) Timer 11 for 118
Since the NOR gate 113 supplies a low-level signal and the NOR gate 113 supplies a no-repel signal, the output becomes a low level. Therefore, input signals of high level and low level are supplied to the NOR gate 68, and the output becomes low level. Therefore, in the end, the output of the NOR gate 75 becomes a low level, and the output of the NOR gate 72 becomes a low level, so that the transistor 74 is turned ON. Therefore, the solenoid valve 10
is OFF, and 1010 and 10b are in communication.

When this rounding compressor 6 is ON, the refrigerant is transferred to the second cooler 7 and the first cooler 4, as shown by the solid line in Figure 6C.
It flows in this order. As a result, the refrigerator compartment 3 is replaced by the second cooler 7.
As mentioned above, the comparator 78 does not reverse the output of the comparator 78 even if the surface temperature of the second cooler 70 becomes 3.5C or less, so the flow direction of the solenoid valve 10 is switched. Without this, the refrigerant continues to flow from the compressor 6 in the order of second cooling 1!7 and first cooling 1!4, cooling the inside of the refrigerator 313. Note that when the air temperature around the thermistor 9 that detects the air temperature of the refrigerator 3 becomes 14C or lower, the relationship between the supplied voltages y, , v□ becomes v, <vIll. Since the output of the comparator 84 is inverted and becomes a low level, the diode 89 becomes conductive, and current flows into the comparator 84 in the order of thermistor 8 → diode 89 → resistor 88. As a result, the input voltage 8 of the inverting terminal of the comparator 78 is forcibly lowered, so that 14% of the input voltage V supplied to the non-inverting terminal becomes Vm<Vs, and the voltage output of the comparator 78 is also inverted. Then, the level is reached. Therefore, the output of the NOR gate 75 becomes a low level, and the output of the NOR gate 72 becomes a low level, turning on the transistor 74. Then, current flows through the relay coil 45, the relay contact 64 turns ON, and current flows through the electromagnetic coil 103, turning on the electromagnetic valve 10 and communicating the first port 10m and the third port 10e. As a result, the flow of the refrigerant flows only to the first cooler 4 as shown by the solid line in FIG. 6B.

At this time, the output of the comparator 78 becomes high level, so the diode 83 becomes non-conductive, and the voltage level supplied to the non-inverting terminal changes from the voltage level IVc to the resistors 79 and 80.
The voltage divided by , is V. This voltage ■ is V, ＞
V, but if the temperature of refrigerator compartment 3 exceeds -40 +
When the voltage becomes 3.5C or less, the output of the comparator 84 is inverted again to a high level.The voltage supplied to the inverting terminal of the comparator 78 is 1V, and the relationship is <V, so the output voltage of the comparator 78 is maintain a high level.

Therefore, the flow of the refrigerant maintains the state shown in FIG. 6B. The relationship between the comparison voltage Vm supplied to the comparator 78 and the horse is that the surface temperature of the second cooler 70 is +3.5C.
The output voltage of the comparator 78 does not invert until the voltage exceeds 131.1C, but when it exceeds +3.5C. , the comparison voltage supplied to the comparator 78 has a relationship of >Vt, so the voltage output of the comparator 78 is inverted. Then, the solenoid valve 10 is turned off again, and the 10th port 10a and the 20th port 10b communicate with each other to form the flow of refrigerant shown in Figure t46C. Then, the inside of the refrigerator compartment 3 is cooled again by the second cooling rI7, but now the cooling iI1. If it is used with the door 13 of the refrigerator compartment 3 open, the inside of the refrigerator compartment 3 will be exposed to outside air, so the interior of the refrigerator compartment 3 will be overloaded. Air ia* does not easily reach a degree below -4C.

A thick layer of frost accumulates on the surface of this rounded cooling I17. The surface of the cooler 70 is then supercooled. However, the temperature of the cooler 7 of the first control circuit 77 is detected. When the surface temperature of the second cooling @ 7 of the thermistor 8 becomes 130 C or lower, the relationship between the input voltages supplied to the inverting terminal and the non-inverting terminal of the comparator 78 becomes <V<V.

The voltage output of the rounding comparator 78 is inverted and becomes a high level, the diode 83 becomes non-conductive, and the output of the NOR gate 72 also becomes a high level.

This turns on the transistor 74, so the solenoid valve 1
0 is ONI, and the first port 10m and the second port iob are blocked. As a result, the second cooler 7 cools lI1.
Cooling of the chamber 3 is forcibly interrupted, and the surface temperature of the second cooler 7 gradually rises, resulting in natural defrosting. When the surface temperature of the second cooler 70 reaches +3.5CK, complete defrosting is completed, the output of the comparator 78 is inverted again, the transistor 73 is turned off, and the solenoid valve 10 is also turned off.
Then, the second cooler 7 starts cooling the inside of the refrigerator compartment 3 again.

Now, if the electromagnetic valve 6 is in the ON state, that is, if the comparator is reached, the relationship between V and V□ is %<vfl, and the output of the comparator 1100 becomes high level. Therefore, the timer 114 is composed of resistor RT and capacitor C! The q terminal becomes high level for a dead time, for example, 5 minutes. This rounding NOR gate 113 forcibly maintains Ka low level for 5 minutes regardless of the signal level supplied from the comparator 110.

This rounding transistor 119 is forced k OFF during this time regardless of any signal. On the other hand, since the Noah gate 118 is forcibly closed for 5 minutes by the signal from the timer 114, the human input signal to the Noah gate 68 becomes low level. As a result, the Noagu 1680 human input signals both go to low level, and the output signal goes to high level. That is, since the transistor 74 is an ON-state layer tt,
Even when the compressor 6 is turned off, the solenoid valve 10 remains in the ON state.

However, since the output level of the timer 114a is inverted after 5 minutes have elapsed, the signal at one terminal from the NOR gate 68 from the NOR gate 11g is at level 7. Regardless of the level, when the compressor 6 is turned off, the solenoid valve 10 performs a forced KOFIP operation after 05 minutes.

Due to this action, according to the refrigeration cycle of the refrigerator of the present invention, the solenoid valve 10 is prevented from being suddenly turned off in synchronization with the compressor 6 from the operating state shown in FIG. 6BK. Since the compressor 6 is turned to 0IFF until t when the thread path of the solenoid valve 10 that forms the cycle is formed, the flow of refrigerant flowing through the refrigeration cycle is stabilized. The design prevents refrigerant from flowing into the cooler 7, thereby preventing overcooling.

Also, at the same time as the compressor 6 turns off, the 71J tube
Flop 122 is released from reset and comparator 78
It is set by the output signal of , and the Q terminal becomes high level. At this time, if the room temperature of refrigerator compartment 3 exceeds +35C,
The output of the comparator 78 is inverted from high level to low level. However, flip-flop Is! 2
0 Since the output signal of the Q terminal is not inverted, the NOR gate 6
The output of No. 7 maintains a low level. Therefore, in this case as well, while the Q terminal of the timer 114 is ON, the NOR gate 6
Since the input signals of 8 are both low level, solenoid valve l
O remains ON. When the number 9 is 2, the solenoid valve 10 can be completely held ON when the compressor 6 is turned OFF, regardless of the room temperature of the cold **S. Then, after 5 minutes have elapsed, both the NOR gate 11 and D inputs become low level, so the output of NOR gate '5□18 becomes high level, the NOR gate 680 output is inverted, and the transistor 744 orν is output.

As is clear from the above detailed explanation of requirements, according to the temperature control circuit of the present invention, the first control circuit 77 detects the temperature of the cooler at two different levels and controls the solenoid valve 0N-O.
Since the FF is controlled, the 20th cooler is protected against noise such as temperature changes or compressor ON/OFF, and the 20th cooler is operated under overload with two temperature levels. Since the IIK cooler is forcibly prevented from overcooling, the temperature detection circuit controls the defrosting time. It also serves as a function and also changes from ON to O of 1 solenoid valve 10.
The transition to FF is when the refrigerant is 0@refrigerant is stable.
As a result, the cooler in the refrigerator compartment will not be overcooled.9 When the compressor is off, the solenoid valve will also be off.9, which has excellent power saving effects, is extremely beneficial in practical use. The structure is as follows.

[Brief explanation of drawings]

The figures are for explaining the present invention in detail, and the #q! iml shows a specific example of the refrigerator according to the present invention. Diagram,
FIG. 2 is a block diagram showing a one-shock control device for a refrigerator according to the present invention, FIG. 3 is a circuit diagram for controlling a refrigerator according to the present invention, and FIG. 4 is a refrigeration system for a refrigerator according to the present invention. FIG. 5 is a circuit diagram showing one embodiment of the rounding means for controlling the flow of the refrigerant installed in the chamber. FIG. FIG. 6 is a diagram showing the change characteristics of the voltage output with respect to the zero temperature and the change in the air temperature inside the refrigerated vehicle, and is a diagram showing the switching state of the refrigerant flow in the refrigeration cycle controlled by the circuit shown in FIG. 4. DESCRIPTION OF SYMBOLS 1... Refrigerator body, 3... Refrigerator compartment, 8.9... Thermistor, 10... Solenoid valve, 14... Control part, 15...
・Operation unit, 17... Control switch, 38...
・Ho+7z? A, 77... first control circuit, 8
5...20th control circuit. Attorney Noriyuki Chika (1 person) Figure 5 4 Figure 6 (B)

Claims (1)

[Claims] A cooler for cooling a refrigerator compartment and a cooler for cooling a freezer compartment are independently provided in each compartment, and the flow of refrigerant to each of the coolers is controlled by selectively switching a solenoid valve, 1) Then, when the compressor is running OFF, the state of the refrigerator compartment is temporarily stored for a set time, the solenoid valve is maintained in the energized state only during this time, and then the energized state is forcibly released. A temperature control method for refrigerators that is characterized by: