JP2588085B2 - Temperature alarm device of constant temperature machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermostat such as a refrigerator or a freezer in which the temperature in a refrigerator is maintained between an upper limit temperature and a lower limit temperature by repeatedly operating and stopping a cooling device. The present invention relates to a temperature alarm device of a thermostat that generates an alarm when a temperature becomes equal to or higher than a high-temperature alarm temperature higher than an upper limit temperature or equal to or lower than a low-temperature alarm temperature lower than a lower limit temperature.

[0002]

2. Description of the Related Art Conventionally, this type of apparatus is disclosed in
As described in Japanese Patent Publication No. 29585, after a certain period of time from when the temperature in the refrigerator becomes equal to or higher than the predetermined high-temperature alarm temperature, and from when the temperature in the refrigerator becomes equal to or lower than the predetermined low-temperature alarm temperature, An alarm is generated after each predetermined time shorter than the predetermined time.

[0003]

By the way, when frozen food or the like is stored in the refrigerator of the thermostat, it is only necessary to defrost the food. Setting the high alarm temperature much higher or setting the low alarm temperature much lower will not cause a problem. However, when storing fresh vegetables in the refrigerator, if the high alarm temperature is set higher than the set temperature, even if the temperature in the refrigerator increases, the user will not notice and the water content of the vegetables will be lost. On the other hand, if the low temperature alarm temperature is set lower, the vegetables are frozen without the user noticing even if the temperature in the refrigerator becomes low, and the quality is deteriorated. That is, when the high temperature alarm temperature and the low temperature alarm temperature with respect to the set temperature in the refrigerator are set to predetermined values, various kinds of foods such as frozen foods or fresh vegetables having different storage conditions are individually separated as necessary. There is a problem that a thermostat cannot be used for the purpose of accommodation.

[0004] If the time from when the temperature in the refrigerator becomes higher than a predetermined high temperature alarm temperature to when an alarm is generated is set to be short, the door of the thermostat is frequently opened and closed. in the case, such as loading and unloading large amounts of food frequently in the case or in the refrigerator supposed to be an alarm often occurs
Can be bothersome. The present invention is intended to solve the above-described problem, and generates an appropriate temperature alarm for a case where various types of foods having various use conditions and storage conditions of a thermostat are individually stored as needed. It is an object of the present invention to provide a temperature alarm device of a thermostat capable of performing the above.

[0005]

Means for Solving the Problems In order to achieve the above object, the constitutional features of the present invention include a temperature sensor for detecting the temperature in the refrigerator, a cooling device for cooling the refrigerator, and a temperature sensor for detecting the temperature. in thermostat having a cooling control means for maintaining between the upper limit temperature and the lower limit temperature of the repetitive control to refrigerator temperature the actuation and stop of the cooling device has a predetermined on the basis of the inside temperature, a high temperature alarm Determine temperature or low temperature alarm temperature
Operation switch for increasing or decreasing the value for
High temperature alarm whose internal temperature is determined based on the increased or decreased value
Low temperature alarm determined based on the temperature or a value that has been increased or decreased
An alarm generating means for generating an alarm when the temperature is lower than the alarm temperature;
When the increased or decreased value is within a predetermined range, the alarm is issued.
Alarm generation by the alarm generation means is allowed, and
If the alarm value is out of the predetermined range,
Alarm generation control means for prohibiting generation of an alarm by the alarm .

[0006]

[0007]

[0008]

[0009]

[0010]

[0011]

[0012]

Operation and effect of the present invention
Operation of the operation switch,
The value for determining the temperature alarm is increased or decreased, and the alarm
The step is higher than the high alarm temperature determined based on the increased or decreased value.
Low temperature alarm temperature determined based on the above or increased or decreased value
An alarm is generated when: Thus, according to the present invention,
If the operation switch is operated, the high alarm temperature or low temperature
Since the alarm temperature is variably set, various foods are stored in the refrigerator.
Even if it exists, the alarm will be
It can certainly occur. Also, alarm generation control means
Is when the increased or decreased value is within a predetermined range.
Allow the generation of alarms by the alarm generation means and increase
Generates an alarm when the reduced value is not within the predetermined range
Prohibits the generation of alarms by means. Therefore, the alarm
If the outbreak becomes a hindrance, for example,
Use the operation switch when you need to
Operation to determine high or low temperature alarm temperature
If you set the value to be out of the predetermined range,
Information can be prohibited, and the usability of the thermostat is good.
It will be good. Also, the prohibition of this alarm can be controlled by operating the operation switch.
Operation switch to disable alarm
Need not be provided.

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram schematically showing an entire thermostat such as a refrigerator and a freezer. This constant temperature machine is provided with an electric compressor 11 provided outside the refrigerator, a condenser 12 and a cooling device including a throttle 13 and an evaporator 14 provided inside the refrigerator, and the refrigerant pressure-fed from the electric compressor 11 in the order described above. By circulating, the inside of the refrigerator is cooled by the evaporator 14. The electric compressor 11 has a relay 16 from an AC power supply 15.
The power is supplied via the normally open contacts x ₁₁ and x ₁₂ and the overload relay 17. Normally open contacts x _11, x
₁₂ is adapted to turn on and off in response to the energization and non-energization of the coil X ₁ of the relay 16. The overload relay 17 is
The overload relay 17 is normally turned on when a thermo switch (not shown) provided in the case of the electric compressor 11 is turned on and off, and the overload relay 17 is normally turned on. When the case temperature of the machine 11 rises and the thermo switch is turned off, the thermo switch is turned off and the power supply path is cut off.

An electromagnetic valve 18 is provided between the discharge port of the electric compressor 11 and the upstream of the evaporator 14. When the valve 18 is turned on, hot gas from the electric compressor 11 is supplied to the evaporator 14. It is supposed to be. Electromagnetic valve 1
8 is connected to the power supply line from the AC power supply 15 through a normally open contact x _21, x ₂₂ of the relay 19, a non-conductive state during the non-supply of power while being set in a conductive state when the power supply Is set. Normally open contacts x ₂₁ , x of relay 19
₂₂ is adapted to turn on and off in response to the energization and non-energization of the coil X ₂ in the relay 19.

The coils X ₁ and X _{2 of the} relays 16 and 19 and the overload relay 17 are connected to a microcomputer 20. The microcomputer 2 includes a transformer 2
A DC voltage is supplied from a power supply circuit 22 connected to the AC power supply 15 through the microcomputer 1, and the microcomputer 20 operates by supplying the DC voltage. This DC voltage is also supplied to a display control circuit 30, a display 31, an alarm drive circuit 32, an alarm 33, and the like, which will be described later.

The microcomputer 20 includes a bus 20a
ROM 20b, CPU 20c, R
It comprises an AM 20d, a defrost timer 20e, a first timer 20f, a second timer 20g, a third timer 20h, an I / O 20i, and the like. The ROM 20b stores programs corresponding to the flowcharts of FIGS. 2 to 11, the CPU 20c executes the programs, and the RAM 20d temporarily stores variables necessary for executing the programs. The defrost timer 20e determines a defrost cycle, and counts up after a predetermined time (for example, 6 to 8 hours) from the start of operation. The first timer 20f counts the time from when the internal temperature reaches the high temperature alarm temperature to when the high temperature alarm signal is generated. The second timer 20g counts the time from when the temperature in the refrigerator reaches the low temperature alarm temperature to when the low temperature alarm signal is generated. Third
The timer 20h counts the time from when the alarm device stop switch 29 is pressed when the low temperature alarm signal or the high temperature alarm signal is generated to when the low temperature alarm or the high temperature alarm is generated again. The I / O 20i transmits and receives signals to and from the outside. In addition to the coils X ₁ and X ₂ of the relays 16 and 19 and the overload relay 17, the I / O 20i also includes an internal temperature sensor 2
3. Defrost thermo switch 24, internal temperature setting switch 2
5. Alarm setting switch 26, up switch 27, down switch 28, alarm stop switch 29, display control circuit 3
0, display 31, alarm drive circuit 32 and alarm 33
Is connected.

The in-compartment temperature sensor 23 is provided in a refrigerator or a freezer, detects the in-compartment temperature T, and outputs a detection signal representing the temperature T. The defrost thermoswitch 24 is constituted by a temperature-sensitive switch attached to the evaporator 14, and is normally turned on (during repeated operation of the operation and stop of the cooling device), and the evaporator 14 completes defrosting. It turns off for the first time when the temperature rises to a certain temperature, and outputs a signal indicating this on / off state. The internal temperature setting switch 25 sets an internal temperature T0 which is a central value of the internal temperature. The alarm setting switch 26 has four setting modes (N = 1 to N) of a high temperature setting temperature TU, a high temperature alarm standby time tu, a low temperature setting temperature TV, and a low temperature alarm standby time tv.
4), and set values in each setting mode. The raising switch 27 raises the set value and the setting mode by “1”. The set value and setting mode of the down switch 28 are lowered by "1". The refrigerator temperature display 31 is constituted by a liquid crystal display or the like for displaying alphanumeric characters, and is controlled by the display control circuit 30. The alarm drive circuit 32 is C
In response to the alarm generation signal from the PU 20c, the alarm 33 is driven to generate an alarm. The alarm device 33 is a buzzer that warns the user of a temperature abnormality in the refrigerator, but may be a device that visually informs the user of the temperature abnormality, such as a lamp.

Next, the operation of the embodiment configured as described above will be described. When a power switch (not shown) is turned on, a DC voltage is supplied from the power supply circuit 22 to the CPU 20c, and the CPU 20c starts executing the main program in step 100 of FIG. Frost flag DEFF, first to third timer flags TMF
1, TMF2, TMF3, High temperature alarm flag HTKF, Low temperature alarm flag LTK
Set F to “0” and defrost timer count value DFTM to “0”
And the RAM 20d including initial setting of the setting mode N to "1" and the internal setting temperature T0 to 5 ° C.
Set the variables in to initial values. After that, the CPU 20c
Repeatedly executes a circulation process including steps 102 to 117. Wherein in the circulation process, CPU 20 c are first in step 102 to release the energization of the coil X ₂ of the relay 19. As a result, the normally open contacts x ₂₁ , x
Since the valve ₂₂ is turned off, the electromagnetic valve 18 is set to a non-conducting state. In this state, hot gas is not supplied to the upstream of the evaporator 14.

Next, the CPU 20c initializes the upper limit temperature TH = T0 + ΔT in step 103 and sets the lower limit temperature TL = T0−ΔT in step 104. T0 = 5 ° C. and ΔT =
It is calculated by adding and subtracting using 1 ° C. The calculated values are TH = 6 ° C. and TL = 4 ° C. at present. Next, the CPU 20c determines whether or not the defrost timer count value DFTM has counted up in step 105, that is, the count value DFTM has been increased for a predetermined time (6.
８8 hours). In this case, since the defrost timer count value DFTM has just been initialized to "0", "NO" is determined in step 105, and the CPU 20c sets the defrost flag DEFF to "0" in step 106. , At step 107
Is determined based on the cooling flag COLF initially set to "1", and the program proceeds to step 108.

In step 108, the CPU 20c inputs a detection signal representing the inside temperature T from the inside temperature sensor 23 and determines whether or not the temperature T is equal to or higher than a predetermined upper limit temperature TH. In the thermostat, immediately after the power switch is turned on, the internal temperature T is equal to or higher than the upper limit temperature TH.
Therefore, the CPU 20c determines in step 108 that "YE
It determines that S ", the coil X ₁ of the relay 16 is energized at step 109, to change the cooling flag COLF step 110 to" 1 ". Thereby, the normally open contact x of the relay 16
_11, x ₁₂ is set to ON state, the electric compressor 11 is supplied with power from the AC power supply 15, the compressor 11 starts to operate, it is supplied cold refrigerant to the evaporator 14 in the refrigerator Begins to cool down.

Next, the CPU 20c returns the program to step 103, and after performing the processing of steps 103 and 104, determines "NO" in step 105, and in step 106, sets the defrost flag DEFF to It is set to "0" indicating that it is not in the state. After that, CP
U20c determines "NO" based on the cooling flag COLF changed to "1" in step 107, and the inside temperature T detected by the inside temperature sensor 23 in step 111 is lower than the lower limit temperature TL. In this case, since the inside of the refrigerator has just started to be cooled and the temperature of the refrigerator is equal to or higher than the lower limit temperature TL, the CPU 20c determines “NO” in step 111, The program returns to step 103, and thereafter, steps 103, 107, 11
3 is repeatedly executed. During this circulation process, the coil X ₁ of the relay 16 continues to be energized,
The inside of the refrigerator is continuously cooled by the evaporator 14, and the temperature T in the refrigerator gradually decreases.

When the internal temperature T falls below the lower limit temperature TL in this way, the CPU 20c executes step 1 described above.
At 11, “YES” is determined, and at Step 112, the energization of the coil X ₁ of the relay 16 is released, and at Step 113, the cooling flag COLF is changed to “0”. Thus, the normally open contacts x _11, x ₁₂ of the relay 16 is set to OFF state,
The supply of electric power from the AC power supply 15 to the electric compressor 11 is stopped, and the compressor 11 is stopped. Therefore, the cooling of the inside of the refrigerator by the evaporator 14 is stopped, and the refrigerator temperature T starts to rise. Next, the program returns to step 103, and after the processing of steps 103 to 106, "YES" is determined in step 107 based on the cooling flag COLF set to "0".
Therefore, the CPU 20c continues to execute steps 103 to 10 until the internal temperature T reaches the preset upper limit temperature TH.
8 is repeatedly executed. Then, when the internal temperature T becomes equal to or higher than the predetermined temperature TH, the CPU 20c determines “YES” in step 108, and starts cooling the internal space by the processing of steps 109 and 110 described above.
By the circulation process including the steps 103 to 113, the operation and the stop of the cooling device are repeatedly controlled, and the internal temperature T is kept between the predetermined temperatures TH to TL.

On the other hand, if the count value DFTM of the defrost timer 20e exceeds the predetermined value CT (corresponding to 6 to 8 hours) during the circulation processing consisting of the above steps 103 to 117, the CPU 20
c is determined to be "YES" in step 105, the defrost flag DEFF is set to "1" in step 114, and then the coil X of the relay 16 and the relay 19 is determined in step 115.
₁ , X ₂ , thereby causing the normally open contacts x ₁₁ , x ₁₂ , x
_21, x ₂₂ is set in the ON state. For this reason, even if the thermostat is inactive and the electric compressor 11 is stopped, the compressor 11 starts to operate, and the electromagnetic valve 18 is opened to release hot gas from the compressor 11 into the valve 18. And is supplied upstream of the evaporator 14. As a result, the evaporator 1
When the temperature of 4 starts to rise, the frost attached to the evaporator 14 is removed.

After the processing of step 115, the CPU 20
c determines in step 116 whether or not the defrost thermoswitch 24 is in the off state. In this case, immediately after the start of the defrosting, the temperature of the evaporator 14 is low and the defrosting thermo switch 24 is in the ON state.
Is determined to be "NO", and the circulation process consisting of steps 115 and 116 is repeatedly executed until the temperature becomes high enough to complete the defrost and the defrost thermo switch 24 is turned off. And step 11
During the circulation process consisting of 5,116, defrost thermo switch 2
4 is turned off, the CPU 20c determines “YES” in step 116, and determines in step 117 that the defrost timer 2
The count value DFTM of 0e cleared to "0", it returns the program to step 102 to release the energization of the coil X ₂ of the relay 19. Thus, the normally open contacts x _21, x ₂₂ of the relay 19 is turned off and the electromagnetic valve 18 is turned off, the supply of hot gas is stopped to the upstream of the evaporator 14. Then, the alternating operation of the operation and the stop of the cooling device is restarted by the circulation processing including steps 103 to 113 described above, and the operation as described above is continuously controlled. During the control operation of such a thermostat, the indicator 31 indicates
As shown in steps 311 and 312 of the "high / low temperature alarm interrupt program" described later, the temperature in the refrigerator is continuously displayed during the cooling operation, and the dF display (display during the defrosting operation) is continuously displayed during the defrosting operation. .

On the other hand, during the circulation processing consisting of steps 103 to 117, the CPU
20c is an "alarm setting interrupt program" consisting of steps 200 to 262 of FIGS.
The "high / low temperature alarm interrupt program" consisting of steps 300 to 342 is executed by interruption.

The "alarm setting interrupt program"
To set the inside set temperature T0, the high set temperature TU, the high temperature alarm standby time tu, the low set temperature TV, and the low temperature alarm standby time tv according to the type of food stored in the store or the operating conditions of the thermostat. Program. Here, the high temperature set temperature TU is the high temperature alarm temperature THH together with the internal set temperature T0.
= T0 + TU, and the low temperature setting temperature TV is the low temperature alarm temperature TLL = T0−TU together with the internal setting temperature T0.
Is defined.

First, the case of setting the internal set temperature T0 will be described. When the internal temperature set switch 25 is pressed while the alarm setting switch 26 is not pressed,
The display unit 31 displays the set temperature T0 in the refrigerator. Display 3
Reference numeral 1 indicates the initially set 5 ° C., while referring to the display result, the user keeps pressing the internal temperature setting switch 25 while holding the up switch 27 or the down switch 2.
By pressing 8, the value of T0 can be raised or lowered to a desired value. That is, the CPU 20c starts executing the program in step 200,
1 is determined as “NO”, and in step 202, “YE
After determining "S", the display 31 is caused to display the in-chamber set temperature T0 in step 203. And step 204
As the ascending switch 27 is kept depressed at .about.206, the internal set temperature T0 is incremented by "1" until it reaches the set upper limit value of 10.degree. Step 20
As the down switch 28 is kept pressed at 7 to 209, the internal set temperature T0 is counted down by "1" until it reaches the set lower limit value of -30 ° C. Here, the “alarm setting interrupt program” is about 5
The execution is repeated every 0 milliseconds.
By keeping pressing, T0 is set to be counted up by "1" about every one second. Similarly, by continuously pressing the down switch 28, T0 becomes approximately 1
The countdown is set to "1" every second. By the interrupt processing for setting the in-compartment set temperature T0, the calculation results of the upper limit temperature TH and the lower limit temperature TL in steps 103 and 104 of the main program are changed. Then, the internal set temperature T0 is set to a desired value T0 =
When the temperature is set to -3 ° C., the internal temperature setting switch 25 is released, and “NO” is determined in step 202, and the setting of the internal temperature T0 ends.

Next, the setting of the high temperature set temperature TU will be described. When the alarm setting switch 26 is pressed, the display 3
When the high temperature set temperature code "1" is displayed at 1, and the internal temperature setting switch 25 is pressed, the high temperature set temperature TU0 is displayed on the display 31. Then, while referring to the display result of the display 31, the user sets the internal temperature setting switch 2
By pressing the up switch 27 or the down switch 28 while keeping 5 pressed, the value of TU can be raised or lowered to a desired value. That is, the CPU 20c determines “YES” in step 201, and proceeds to step 21.
After determining “NO” at 0, 213, step 216 is executed.
Is determined as “YES” based on the initial setting value N = 1. Further, the CPU 20c determines in step 217 that “YE
After determining "S", the display 31 displays the high temperature set temperature TU0. Then, in steps 219 to 222, the ascent switch 27 is kept pressed, so that the high temperature set temperature T
U is counted up by “1” until it reaches the set upper limit of 16 ° C. At step 222, the high temperature set temperature TU is converted into a signal TU0 for display by the display 31. Further, by keeping the down switch 28 pressed in steps 224 to 227, the high-temperature set temperature TU is counted down by "1" until it reaches the set lower limit of 5 ° C.
At 7, the high temperature set temperature TU is converted into a signal TU0 for display by the display 31. Here, as described above, the high temperature set temperature TU is incremented by "1" about every one second by keeping the raising switch 27 pressed, and
When the down switch 28 is kept pressed, the countdown is set to "1" every about one second. Then, when the high temperature setting temperature TU is set to a desired value TU = 5 ° C., the internal temperature setting switch 25 is released, and “NO” is determined in step 217, and “1” is displayed on the display 31 in step 228. Is displayed and the setting of the high temperature set temperature TU is completed. The high-temperature warning prohibition setting portion of steps 220 and 223 will be described later.

Next, the high-temperature warning standby time tu is set. Here, the change of each setting code N = 1 to 4 by the program shown in FIG. 4 will be described. When the alarm setting switch 26 is depressed, a high temperature setting temperature setting code "1" is displayed on the display 31. While referring to the display result, the user keeps pressing the alarm setting switch 26 and raises the up switch 27 or the down switch 28. By pressing, the value of the setting mode N can be raised or lowered to set N to a desired value. That is, after determining “YES” in step 201, the CPU 20c determines “NO” in steps 210 and 213, determines “YES” in step 216, and determines “NO” in step 217. Thereafter, at step 228, the high temperature set temperature setting code "1" is displayed on the display 31. Then, steps 210 to 212
When the ascending switch 27 is kept pressed, the count-up is incremented by "1" until the setting mode N reaches the setting upper limit 4. Further, in steps 213 to 215, the down mode switch 28 is kept pressed, so that the setting mode N
Is counted down by "1" until the lower limit 1 is reached. Here, as described above, in the setting mode N, the up switch 27 is kept pressed, and the count is incremented by “1” about every one second.
It is set so that the countdown is performed by "1" every about one second when the button 8 is kept pressed. Then, when the setting mode N is set to the value N = 2 representing the high-temperature warning standby time tu, "2" is displayed on the display 31 in step 238, and the setting of the high-temperature set temperature TU is terminated.

When the internal temperature setting switch 25 is pressed in a state where N = 2, the display 31 displays a high-temperature alarm standby time tu0, and the user refers to the display result to set the internal temperature. By holding down the switch 25 and pressing the up switch 27 or the down switch 28, tu
Can be set to a desired value by raising or lowering the value. That is, after determining “NO” in step 216, CPU 20 c determines “YES” based on setting result N = 2 in step 229, and determines “YE” in step 230.
After determining "S", the display 31 is caused to display the high-temperature warning standby time tu at step 231. And step 2
As the ascending switch 27 is kept depressed at 32 to 234, the high-temperature warning standby time tu is counted up by "1" until the high-temperature alarm waiting time tu reaches the set upper limit of 60 min. Also, in steps 235 to 237, the high temperature alarm standby time tu is set to 5 min.
Is counted down by "1" until it reaches. Here, as described above, the high-temperature warning standby time tu is set to “1” every about one second by keeping the up switch 27 pressed.
The count is incremented by one, and the countdown is set to be decremented by "1" about every one second by keeping the down switch 28 pressed. When the high temperature alarm standby time tu is set to the desired value of 60 min., The internal temperature setting switch 25 is released, and the determination in step 230 is “NO”, and the display 31 displays “2” in step 238. Is displayed, and the setting of the high temperature alarm standby time tu ends.

Next, the low temperature setting temperature TV is set.
First, the low temperature setting temperature setting code N = 3 is set by the above-described program of FIG. When the internal temperature setting switch 25 is further pressed in this state,
The low-temperature set temperature TV0 is displayed on the display 31. While referring to the display result, the user keeps pushing the internal temperature setting switch 25 and presses the up switch 27 or the down switch 2.
By pressing 8, the value of TV can be raised or lowered to a desired value. That is, after determining “NO” in steps 216 and 229, the CPU 20c determines “YES” based on the set value N = 3 in step 239, and displays the low temperature set temperature TV0 on the display 31 in step 241.
Is displayed. Then, in steps 242 to 245, the raising switch 27 is kept depressed, so that the low-temperature set temperature TV is counted up by "1" until the low-temperature set temperature TV reaches the set upper limit of 16 ° C. It is converted into a display signal TV0. Further, by keeping the down switch 28 pressed in steps 247 to 250, the low temperature set temperature TV becomes lower than the set lower limit 5.
The countdown is performed by "1" until the temperature reaches ° C. At step 250, the low temperature set temperature TV is converted into a signal TV0 for display by the display 31. Here, as described above, the low-temperature set temperature TV is incremented by "1" about every one second by keeping the raising switch 27 pressed, and
Further, it is set so that the countdown is performed by "1" every approximately one second when the down switch 28 is continuously pressed. Then, the low temperature setting temperature TV is set to a desired value TV = 5.
° C, the internal temperature setting switch 25 is released, and “NO” is determined in step 240, and
At step 51, "3" is displayed on the display 31, and the setting of the low temperature set temperature TV is completed. Steps 243 and 246
The low-temperature alarm prohibition setting portion will be described later.

Next, the low-temperature warning standby time tv is set. First, the low temperature alarm standby time setting code N = 4 is set by the above-described program of FIG. Internal temperature setting switch 2 with N = 4
5 is pressed, the low-temperature warning standby time tv is displayed on the display 31. While referring to the display result, the user keeps pressing the internal temperature setting switch 25 and raises the raising switch 27.
Alternatively, by pressing the down switch 28, the value of tv can be raised or lowered to a desired value. That is,
After determining "NO" in steps 216, 229 and 239, the CPU 20c determines "YES" in step 252 based on the setting result N = 4, and in step 253
Then, at step 254, the display 31 displays the low-temperature warning standby time tv. And
In steps 255 to 257, the low temperature alarm standby time tv is set to the upper limit 60 by keeping the up switch 27 pressed.
The count is incremented by "1" until it reaches min. Also, in steps 258 to 260, the down switch 28 is kept depressed, so that the low-temperature warning standby time tv is counted down by "1" until it reaches the set lower limit of 5 min. Here, as described above, the low temperature warning standby time tv is
When the up switch 27 is kept pressed, the count is incremented by "1" about every one second, and when the down switch 28 is kept pressed, it is counted down by "1" every about 1 second. I have. And
When the low temperature alarm standby time tv is set to a desired value of 5 min.,
The internal temperature setting switch 25 is released and “NO” is determined in the step 253, and the display 31 is determined in the step 261.
Is displayed, and the setting of the low-temperature alarm standby time tv is ended. In step 262, the execution of the "alarm setting interrupt program" is ended. In the above setting process, the high temperature alarm temperature THH and the low temperature alarm temperature TLL are set by increasing / decreasing the high temperature set temperature TU and the low temperature set temperature TV with respect to the internal set temperature T0.
When the difference between HH and the low temperature alarm temperature TLL is constant, there is an effect that it is not necessary to reset TU and TV when changing T0 and changing THH and TLL.

Next, the execution of the "high / low temperature alarm interrupt program" shown in FIGS. CP
U20c starts execution of the program in step 300, and determines in step 301 whether or not "c" indicating prohibition of alarm generation is set in the high temperature set temperature display TU0. Here, since the high temperature alarm is generated, the CPU 20c shifts the program to step 302 based on the determination of “NO” in step 301, and sets the internal set temperature TO and the high temperature set temperature TU. Then, the high alarm temperature THH = TO + TU is calculated. here,
For TO and TU, the set values of −3 ° C. and 5 ° C. set in the “alarm setting interrupt program” are used, and THH = 2 ° C. is calculated. Next, at step 303, it is determined whether or not the inside temperature T is equal to or higher than the high temperature alarm temperature THH. At the start of the operation of the thermostat, the internal temperature T is equal to or higher than the high temperature alarm temperature THH, so the CPU 20c determines "YES" in step 303, and counts the high temperature alarm standby time tu in step 304. It is determined whether 20f is operating. The CPU 20c determines “YES” in step 304, that is,
It is determined that the timer flag TMF1 indicates the non-operation state “0”, and the program shifts to step 305 to execute the first
The timer 20f is started, and at step 306, the first timer flag TMF1 is changed to "1" indicating the operating state, and the program shifts to step 307. Here, the "high / low temperature alarm interrupt program" is repeatedly executed about every 50 milliseconds as described above, and the first timer 20f adds up this repetition time to count up a predetermined high temperature alarm standby time tu. . Further, when the first timer flag TMF1 is changed to "1" by repeating the "high / low temperature alarm interrupt program", step 30 is executed.
4 is "NO", and the program proceeds to step 30.
7 is performed. Then, the CPU 20c proceeds to step 30.
At 7, it is determined whether or not the first timer 20f has counted up, and if not, the program proceeds to step 315 to perform the following processing.
If the first timer 20f counts up after the high temperature alarm standby time has elapsed, the CPU 20c proceeds to step 3
Based on the determination of "YES" at 07, the high temperature warning flag HTKF is changed to "1" at step 308 to indicate that the inside of the refrigerator is in the high temperature warning state.

Here, during the processing of the program from step 301 to step 308, if the temperature in the refrigerator becomes lower than the high temperature alarm temperature THH due to the operation of the cooling device, the CPU 2
In step 0c, based on the determination of "NO" in step 303, the program shifts to step 309 to change the first timer flag TMF1 to "0", and in step 310 whether the thermostat is in the cooling operation state. Alternatively, it is determined whether the vehicle is in the defrost operation state, that is, whether the defrost flag DEFF is “0”. At present, the cooling device is in the cooling operation state,
PU 20c determines “YES” in step 310,
In step 311, the display control circuit 3 outputs the internal temperature display signal.
0, and the display 31 displays the temperature in the refrigerator. Further, the CPU 20c determines in step 313 that the first timer 20
At step 314, the high temperature alarm flag HTKF is set to "0". Step 3 above
When the cooling device is in the defrosting state during the processing of the program from 01 to 314, the CPU 20c determines “NO” in step 310 and outputs a dF display signal to the display control circuit 30 in step 312. And display 31
To display the dF state.

Next, the low-temperature warning program from step 315 to step 328 will be described. The CPU 20c determines in step 315 whether or not "c" for inhibiting the generation of a warning is set in the low-temperature set temperature display TV0. Here, since a low temperature alarm is generated, C
Based on the determination of "NO" in step 315, the PU 20c shifts the program to step 316, and calculates the low-temperature alarm temperature TLL = TO-TV by subtracting the low-temperature set temperature TV from the internal set temperature TO. I do. Where TO
And TV are set at −3 ° C. and 5 ° C. set by the “alarm setting interrupt program”, and TLL is set to −8 ° C. Next, at step 317, it is determined whether or not the inside temperature T is lower than TLL. At the start of the operation of the thermostat, the internal temperature T is equal to or higher than TLL.
20c is based on the determination of “NO” in step 317,
The program shifts to step 318 to set the second timer flag TMF2 for counting the low-temperature warning standby time tv to the non-counting state "0". At step 319, the thermostat is in the cooling operation state or the defrosting operation state. Is determined, that is, whether the defrost flag DEFF is “0” or not. At present, the cooling device is in the cooling operation state,
U20c determines "YES" in step 319, and outputs the in-chamber temperature display signal in step 320 to display control circuit 30.
And the display 31 displays the temperature in the refrigerator. Further, the CPU 20c determines in step 321 that the second timer 20
g is reset, and at step 322, the low temperature alarm flag LTKF is set to "0" to indicate that the inside of the refrigerator is not in the low temperature alarm state. Also, in the course of the processing of the program from step 315 to 322, when the cooling device is in the defrost state, the CPU 20c determines “N” in step 319.
In step 323, a dF display signal is output to the display control circuit 30, and the display 31 displays the dF state.

In the process of the program from step 315 to step 323, if the internal temperature T becomes lower than the low temperature warning temperature TLL due to the operation of the cooling device, the CPU 20c determines "YES" in step 317, and proceeds to step 317.
At 24, it is determined whether the second timer 20g is operating. The CPU 20c determines “YES” in step 324, that is, the second timer flag TMF2 is “0” based on the processing result in step 318, shifts the program to step 325, starts the second timer 20g, and In step 326, the second timer flag TMF2 is changed to "1" indicating the operating state. Here, the "high / low temperature alarm interrupt program" is repeatedly executed about every 50 milliseconds, and the second timer 20g accumulates the repetition time to obtain a predetermined low temperature alarm standby time tv.
It counts up by "1" until it becomes. When the second timer flag TMF2 is changed to "1" by repeating the "high / low temperature alarm interrupt program", "NO" is determined in the step 324, and the program shifts to the step 327. Then, in step 327, the CPU 20c determines whether or not the second timer 20g has counted up. If not, the CPU 20c shifts the program to step 329 and performs the following processing. When the second timer 20g counts up after the low-temperature warning standby time tv has elapsed, the CPU 20c proceeds to step 3 based on the determination of "YES" in step 327.
At 28, the low temperature warning flag HTKF is changed to "1", indicating that the inside of the refrigerator has entered the low temperature warning state.

Normally, the operation of the thermostat is normally performed and the temperature T in the refrigerator is in a normal state.
Determines "YES" in steps 329 and 330, generates an alarm stop signal in step 331, and in response, prevents the alarm device drive circuit 32 from generating an abnormal temperature alarm by the alarm device 33.

Here, when the inside of the chamber of the constant temperature machine is in the high temperature alarm state, the CPU 20c changes the high temperature alarm flag HTKF to "1" in step 308, and "NO" in step 329.
In step 332, a high temperature alarm signal is output to the display control circuit 30 and the high temperature alarm display "E1" is displayed on the display 31.
Is performed. Then, in step 333, it is determined whether or not the alarm stop switch 29 is pressed.
In this case, since the switch 29 has not been depressed, "YES" is determined in the step 333 and "NO" is determined in the step 334, and the program shifts to the step 335. In step 335, the CPU 20c outputs an alarm generation signal to the alarm device drive circuit 32 to drive the alarm device 33 to generate a high temperature alarm. Then, the CPU 20c sets the third timer flag TMF3 to “0” in step 336, and ends the execution of the “high / low temperature alarm interrupt program” in step 337.

When the inside of the chamber of the constant temperature machine enters the low-temperature alarm state, the CPU 20c sets a low-temperature alarm flag in step 328.
Change LTKF to “1” and “YES” in step 329
Then, based on the determination of "NO" in step 330, a low-temperature warning signal is output to the display control circuit 30 in step 338, and the display 31 performs the low-temperature warning display "E2". Then, in step 333, “YES” is determined, and in step 334, “NO” is determined based on the turning off of the alarm stop switch, and the program shifts to step 335. In step 335, the CPU 20c outputs an alarm generation signal to the alarm device drive circuit 32 to drive the alarm device 33 to generate a low temperature alarm. Then, the CPU 20c sets the third timer flag TMF3 to "0" in step 336, and ends the execution of the "high / low temperature warning interrupt program".

As is apparent from the above description, in the present embodiment, the setting of the high temperature alarm temperature THH can be changed, so that, for example, when storing frozen food, it is only necessary to defrost the food. The high temperature setting temperature can be set relatively high. On the other hand, when fresh vegetables are stored in the refrigerator, for example, the high temperature setting temperature can be set lower so that the water content is not lost. In addition, the setting of the low temperature alarm temperature TLL can be changed,
For example, when storing frozen foods in a refrigerator, the low temperature setting temperature can be set lower because the foods need not be thawed. Further, when storing vegetables, the low temperature setting temperature can be set higher so as not to freeze.

Since the setting of the high-temperature alarm standby time tu can be changed, for example, when a large amount of food is frequently taken in and out of the refrigerator, the high-temperature alarm standby time tu is set to be longer. be able to. In the case of fresh vegetables whose quality is likely to be impaired due to excessive heating, the high temperature warning standby time can be set shorter. Further, since the setting of the low-temperature warning time tv can be changed, for example, when storing frozen foods that do not need to be considered too cold, the low-temperature warning standby time may be set longer, or the cooling may be performed. In the case of fresh vegetables whose quality is likely to be impaired by passing, the low-temperature warning standby time can be set shorter. Thus, the high-temperature alarm temperature THH, the high-temperature alarm standby time tu, the low-temperature alarm temperature TLL, and the low-temperature alarm standby time tv are appropriately set according to the type of food stored in the refrigerator and according to the use conditions of the thermostat. Therefore, a high temperature abnormality or a low temperature abnormality in the thermostat can be appropriately alarmed.

When the "high / low temperature alarm interrupt program" is executed, for example, when a large amount of food is frequently taken in and out of the refrigerator, the alarm device stop switch 29 is set to prevent an alarm from being generated frequently. When the switch 29 is turned on, a predetermined alarm grace time tw is added to the high temperature alarm standby time tu or the low temperature alarm standby time tv, and the generation of an alarm within the alarm grace time tw is stopped. be able to. In this case, the CPU 20c starts the third timer 20h in step 339 based on the determination of "YES" based on the alarm device stop switch 29 being turned on in step 334 of the "high / low temperature alarm interrupt program" and step 340. Then, the third timer flag TMF3 is changed to "1", and in step 341, it is determined whether or not the third timer 20h has counted up. If the third timer 20h has not yet counted up, the CPU 20c proceeds to step 34.
In step 1, it is determined to be "N0", and in step 342, an alarm stop signal is output to prevent the alarm 33 from generating an alarm. When the third timer 20h counts up after the alarm grace time tw has elapsed, the CPU 20c
Is determined as “YES” in the step 341 and the step 33 is executed.
At 5, an alarm generation signal is output to the alarm device drive circuit 32 to generate an alarm at the alarm device 33, so that an abnormality in the internal temperature can be alarmed. Then, the CPU 20c determines in step 336
Then, the third timer flag TMF3 is changed to "0", and the execution of the "high / low temperature alarm interrupt program" is terminated in step 337. In such a case where a large amount of food is frequently taken in and out of the refrigerator, the alarm stop switch 29 is provided to add the alarm grace time tw to the high temperature alarm standby time tu or the low temperature alarm standby time tv. By doing so, it is possible to prevent an alarm from being frequently generated. Further, in this case, the alarm is generated again after the elapse of the alarm allowance time tw, so that the alarm setting is not released.

Further, in the case where a large amount of food is frequently taken in and out of the refrigerator, instead of providing the alarm stop switch 29, the step 223 of the "alarm setting interrupt program" sets the temperature to the high temperature set temperature TU0 or the step 223. By setting "c" to the low temperature setting temperature TV0 at 246, no alarm is generated after the generation of the high / low temperature alarm signal, and the trouble caused by frequent alarms can be avoided. That is, if it is not desired to generate a high temperature alarm, as shown in FIG. 5, when the high temperature set temperature TU is set, the raising switch 27 is kept pressed in step 219 to set TU to the set upper limit value of 16 ° C. "YE
S ”, and TU0 =“ c ”is set in step 223. Then, "YES" is determined in step 301 of the "high / low temperature alarm interrupt program", and furthermore, HTKF is set to "0" in step 314, whereby generation of the high temperature alarm is prohibited. If the user does not want to generate a low-temperature alarm, as shown in FIG.
When TV is set to the set upper limit value of 16 ° C. by pressing and holding 7, “YES” is determined in the step 243, and the step 246 is performed.
Is set to TV0 = "c". Then, in step 315 of the “high / low temperature alarm interrupt program”, “YE
S ", and the LTKF is set to" 0 "in step 322, thereby prohibiting the generation of the low temperature alarm. Further, such an alarm prohibition setting can be performed at the time of setting the alarm temperature, so that the operation is simple and there is no need to provide a separate switch or the like, so that the alarm device can be configured at low cost.

[Brief description of the drawings]

FIG. 1 is an overall schematic block diagram of a thermostat according to an embodiment of the present invention.

FIG. 2 is a flowchart of a main program executed by the microcomputer of FIG. 1;

FIG. 3 is a part of a flowchart of an alarm setting interrupt program executed by the microcomputer of FIG. 1;

FIG. 4 is a part of a flowchart of the alarm setting interrupt program.

FIG. 5 is a part of a flowchart of the alarm setting interrupt program.

FIG. 6 is a part of a flowchart of the alarm setting interrupt program.

FIG. 7 is a part of a flowchart of the alarm setting interrupt program.

FIG. 8 is a part of a flowchart of the alarm setting interrupt program.

FIG. 9 is a part of a flowchart of a high / low temperature alarm interrupt program executed by the microcomputer of FIG. 1;

FIG. 10 is a part of a flowchart of the high / low temperature alarm interrupt program.

FIG. 11 is a part of a flowchart of the high / low temperature alarm interrupt program.

[Explanation of symbols]

11 ... electric compressor, 12 ... condenser, 13 ... throttle, 14 ...
Evaporator, 16, 19 relay, 20 microcomputer, 23 internal temperature sensor, 25 internal temperature setting switch, 26 alarm setting switch, 27 upward switch,
28 ... down switch, 29 ... alarm stop switch, 31 ...
Display, 33: alarm, TH: upper limit temperature, TL: lower limit temperature, THH: high temperature alarm temperature, TLL: low temperature alarm temperature.

Claims (1)

(57) [Claims] A temperature sensor for detecting a temperature in the refrigerator; a cooling device for cooling the refrigerator; and a refrigerator that repeatedly controls the operation and stop of the cooling device based on the temperature in the refrigerator detected by the temperature sensor. In a thermostat provided with cooling control means for maintaining the inside temperature between a predetermined upper limit temperature and a lower limit temperature, a value for determining a high temperature alarm temperature or a low temperature alarm temperature is controlled.
An operation switch that increases or decreases according to the operation, and a high-temperature alarm that determines the internal temperature based on the increased or decreased value.
Low temperature determined based on the value above or below the reported temperature
An alarm generating means for generating an alarm when the temperature is equal to or lower than the alarm temperature, and when the increased or decreased value is within a predetermined range,
Alarm generation by alarm generation means is allowed, and
Alarm generation means when the set value is not in the predetermined range
And a warning generation control means for prohibiting the generation of a warning by the temperature control device.