JPH0122921B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a temperature control device with little temperature fluctuation.

Equipment that requires a large amount of heat uses a radiator with a large heat capacity, and temperature is controlled by passing steam through or blocking it.
When the temperature fluctuates widely, for example, when used in a clothes dryer, even if the average temperature is at an appropriate value, the maximum temperature can become extremely high, which can have a negative effect on the clothes.

The present invention divides the radiator into several stages, and at the beginning of operation, the number of radiators corresponding to the set temperature is activated to raise the temperature to the set temperature, and once the set temperature is reached, the time required for the temperature to drop below the set temperature is increased. They measured the temperature and adjusted the number of radiator stages to be restarted depending on the length of time, thereby reducing temperature fluctuations. That is, if the time is long, the number of radiator stages to be restarted is reduced, and if the time is short, the number of stages is increased.

The present invention will be described below based on examples. Reference numeral 1 denotes a clothes dryer having a door 2 for loading clothes in the center of the front, and a main switch 3, a dryness adjustment knob 4, and a steam pressure gauge 5 on the top. In addition, there is a keyboard 6
A fluorescent tube 7 for time display and a fluorescent tube 8 for temperature display are provided.

Figure 2 shows the internal structure of the clothes dryer.
A drying drum 9 is provided opposite the clothes input door 2, and first, second, and third radiators 10, 11, and 12 are provided above the drum, and a lint filter 13 and a lint filter 13 are provided below. A blower 14 is provided, the blower being driven by a motor 15 and the drying drum 9 being driven by another motor 16. 17 is a thermistor for detecting temperature on the inlet side of the drying drum, and 18 is a thermistor for detecting temperature on the outlet side of the drying drum. The first, second, and third radiators 10, 11, and 12 each consist of a meandering pipe for passing steam and a large number of plate-like fins, and the ends of each of the meandering pipes Steam valves 19, 20, and 21 are inserted in the respective parts. Reference numeral 22 denotes a live steam valve for blowing live steam into the drying drum 9. By opening this electromagnetic valve and sucking live steam into the drying drum 9, the clothes in the drum are moistened and easily ironed. That's what I do.

During normal operation, this live steam valve 22 is closed, the three steam valves 19, 20, and 21 are open, and all the radiators 10, 11, and 12 are operated, and the motor 1
6 and 15 rotate the drying drum 9 and the blower 14. Air is sucked in through the intake port 23a by the rotation of the blower, heated by the first, second, and third radiators 10, 11, and 12, and then passed through the drying drum 9, where moisture is removed from the clothes. It passes through the post-lint filter 13 and the blower 14 and is discharged from the exhaust port 23b.

FIG. 3 is a block diagram of the control circuit. An address bus 26 for specifying the address of the program is connected between the central processing unit (hereinafter referred to as CPU) containing the write memory 24 and the ROM 25 containing the program. (12 bits) and a data bus 27 (8 bits) for transferring instructions to the CPU 24. ICs 28 and 29 for input/output expansion are connected to the CPU 24, so that it can handle a large number of inputs/outputs. Also, this
The inputs of the CPU 24 include 2 bits from the D/A converter 30 that outputs the inlet and outlet temperatures of the drying drum and the set values of the dryness adjustment knob, as well as 2 bits from the D/A converter 30 that outputs the drying drum inlet and outlet temperatures and the set values of the dryness adjustment knob, as well as the settings for the operating course, time and temperature, and the start and end of the operation. 4 bits from keyboard 6 for stop operation and 50/60
3 bits from the switches 31 such as the Hz changeover switch, door switch, and thermal switch, and 1 bit from the reset circuit 32 for resetting the CPU 24 when the power is turned on, generate a rectangular wave voltage of the power supply frequency and reset the CPU 24. There is one bit from the external interrupt circuit 33 that is input to the external interrupt terminal. In addition, the output of the CPU 24 is sent to the time display fluorescent tube 7, the temperature display fluorescent tube 8, the D/A converter 30, and the radiator steam valves 19, 20. , 21, the live steam valve 22, the fan motor 15, the electromagnetic relays 16a and 16b for left and right rotation of the drum motor, and the buzzer 34.

Next, the operation will be explained according to the flowchart shown in FIG. First, when the power is turned on, the reset circuit 3
2 is activated, the CPU 24 starts execution from the instruction stored at the start address of the ROM 25, and after resetting all outputs and clearing the RAM area,
Enter the open/closed state of the 50/60Hz selector switch and set the 50Hz
Decide whether to use the specifications or the 60Hz specifications. Next, the D/A converter 30 reads the inlet and outlet temperatures of the drying drum detected by the thermistors 17 and 18 and the setting values of the dryness adjustment knob, and
The input on the keyboard 6 is checked while displaying the time and temperature, and when there is an input, the process corresponding to the input is performed, for example, when the automatic detection course is pressed, the automatic detection course is set. Further, time counting is also performed in parallel based on input from the external interrupt circuit 33. When the start switch in the keyboard 6 is pressed after the course has been completely set, the state of the door switch is input, and if the door is closed, the machine enters the operating state. During operation, the blower 14 is rotated by the fan motor 15, and the drum motor 16 is alternately rotated left and right by the electromagnetic relays 16a and 16b for left and right rotation, thereby reversing the drying drum 9. Further, the steam valves 19, 20, and 21 are opened and closed according to the set temperature of the drying drum 9 to control the temperature.

Figures 4(c) and 4(d) are flowcharts for temperature control. When neither the inlet temperature nor the outlet temperature of the drying drum 9 has reached the set value, the steam valves 19, 20, 21 are opened to allow steam to pass through the radiators 10, 11, 12, heating the air sucked in from the intake port 23a. and blow into the drying drum 9. At the start of operation, the CPU 24 controls the steam valves 19 and 2 according to the temperature set value of the thermistor 17 that measures the inlet temperature of the drying drum.
Determine the number of valve openings of 0 and 21. That is, the number of stages of radiators 10, 11, and 12 is adjusted. For example, when the set temperature is 140℃ or higher, the steam valve 19,
All three steam valves 19 and 21 are opened when the temperature is between 140°C and 90°C, and only the steam valve 191 is opened when the temperature is below 90°C. By doing this, even when the set temperature of the drying drum is low, the temperature rise after the set temperature is reached and the steam valves 19, 20, 21 are closed, the so-called push-up, can be suppressed to a minimum, thereby improving accuracy. It is possible to perform high temperature control.

In addition, with steam-type clothes dryers, the steam pressure may decrease due to the relationship with other steam-consuming equipment, and the set inlet temperature may not be reached.
A distinction is made between this and cases where steam cannot be supplied, such as when the main valve of the steam piping is closed, and if steam cannot be supplied, the operation is stopped and an alarm is issued. That is, if the inlet temperature has not yet reached the set temperature after 5 minutes have passed after the start of operation, the inlet temperature detected by the thermistor 17 at that time is stored in a predetermined location in the RAM, and then the number of open steam valves is set to one. To increase. However, if all three steam valves 19, 20, and 21 are already open, the number of open valves cannot be increased, so the current state is maintained. If the set temperature is still not reached even after 6 minutes have passed after the start of operation, the number of open steam valves 19, 20, and 21 is further increased by one. If the set temperature is still not reached 7 minutes after the start of operation, compare the inlet temperature at that time with the inlet temperature 5 minutes after the start of operation stored in a predetermined location in the RAM, and check whether the temperature at that time is higher. If the temperature is 10°C or higher, a continuation flag is set in a designated location in the RAM and operation continues. When the temperature difference is less than 10℃, it is determined that steam cannot be supplied, the operation is stopped, and an alarm is issued.

In this way, the CPU 24 executes heating control using a predetermined radiator, and during this time,
A comparison section compares when the measured inlet temperature or outlet temperature of the drying drum 9 reaches a set value. When the measured temperature at the inlet or outlet exceeds the set temperature, a comparison section signal is output, and the steam valves 19 and 2
0 and 21 to stop heating and wait for the measured temperatures at the inlet and outlet to drop below the set temperature. Thus, when the measured temperatures at the inlet and outlet become lower than the set temperature, the CPU 24 stops outputting the comparator signal. In addition, the CPU 24 has a timekeeping section.
The time from when the comparator signal is output until it stops,
That is, the time from when the measured temperature at the inlet or outlet exceeds the set temperature until the measured temperature at the inlet and outlet becomes below the set temperature after heating is stopped is measured.

At this time, the drying drum 9 continues to rotate.
If the automatic detection course switch is pressed, the cold air operation is switched to when the measured temperature at the outlet of the drying drum 9 exceeds the set temperature.

As mentioned above, when the steam valves 19, 20, 21 are closed and both the inlet temperature and the outlet temperature of the drying drum are below the set values, the steam valves 19, 20, 21 will be opened again. The number of valve openings is determined by the timing content of the timing section. To explain this based on the flowchart in FIG. 4D, the CPU 24
If the timing is short (less than 40 seconds), open the same steam valve as before fully closing, and if it is less than 80 seconds, open the number of steam valves that were open before fully closing by one less. , when the time is longer than 80 seconds, adjust the number of stages so that the number of steam valves reduced by 2 is opened. However, in either case, at least one steam valve should be adjusted to be open.
The reason why it takes a long time for the temperature to drop below the set value after closing the steam valve is because the heat source is too large and the temperature fluctuations become large. By settling on the optimum number of steam valve openings, temperature fluctuations can be kept to a minimum. If the temperature further drops below the set value and the set value is not reached again after 40 seconds have passed after opening any of the steam valves 19, 20, and 21, increase the number of steam valve openings by one step. I'm trying to raise the temperature. This is to maintain the temperature at the set value even if the steam pressure drops during operation. All hot air operations except the automatic course end when the set time has elapsed, and the mode shifts to cold air operation. Cold air operation is designed to last for a set time or end when the outlet temperature drops below 45°C.

As described above, in the present invention, if the boost time from reaching the set temperature until the temperature drops below the set temperature again is long, the heat generation amount of the radiator is automatically reduced and the operation is performed when the temperature falls below the set temperature. , it is possible to provide a temperature control device that can control the temperature so that the boosting time is minimized, and therefore has little temperature fluctuation.Especially when used in a clothes dryer, it is possible to provide a temperature control device that can temporarily dry clothes. The drying temperature can be maintained according to the type of fiber without exposing it to high temperatures.

[Brief explanation of drawings]

Fig. 1 is a front view of a clothes dryer equipped with the heating device of the present invention, Fig. 2 is a vertical side view of the same, Fig. 3 is a block diagram of the control device, Fig. 4 is a, b, c,
2 is a flowchart, and FIG. 5 is a block diagram showing the configuration of the present invention. 10...First radiator, 11...Second radiator, 12...Third radiator, 17...Drying drum inlet side thermistor, 18...Drying drum outlet side thermistor.

Claims (1)

[Claims] 1. In a temperature control device that heats and maintains the sucked air to a preset temperature using a radiator divided into multiple stages, A temperature measuring means such as a thermistor that measures the temperature of the heated air, outputs a signal when the measured temperature at the inlet or outlet exceeds the set temperature, and outputs a signal when the measured temperature at the inlet or outlet falls below the set temperature. a comparison section that stops, and a heating control section that causes the radiator to heat until the comparison section outputs a signal;
a timing section that measures the time from when the comparison section outputs the signal until it stops outputting the signal; and a timing section that determines the number of stages of the radiator according to the set temperature at the start of operation, and uses this determined number of stages as the timing section. 1. A temperature control device comprising: a step number adjustment section that decreases the number of steps as the time period increases.