JPH03284300A - Controller for dryer - Google Patents

Abstract

PURPOSE:To judge the amount of load of clothes to be dried, and suppose remaining time from the starting current of a motor for driving a rotating drum and the rate of change in temperature by providing a second judging means for judging a second load constant from the rate of rise in temperature processed by an operating means and a time determining means for determining residual drying time corresponding to the amount of clothes to be dried from first and second load constants judged by respective judging means. CONSTITUTION:A temperature detecting means 103 detects exhaust temperature from a drying chamber after a drying is started. The value of the detected exhaust temperature is input to an operating means 104. The operating means 104 calculates the rate of rise in temperature after prescribed time from the start of drying from the value. The calculated rate of rise in temperature is input to a second judging means 105. The second judging means 105 judges a second load constant corresponding to a load amount from the rate of rise in temperature and outputs to a time determining means 106. The time determining means 106 determines residual drying time corresponding to the load amount based on the combination of the input first and second load constants. Thus, since the magnitude of load amount is also judged from the rate of rise in temperature and the load amount is finally judged based on the combination of the judged results to determine the residual drying time, error in the residual drying time can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a dryer control device for a dryer that is widely used for drying clothes at home.

(b) Conventional technology Conventionally, this type of dryer is
It is known that the method is described in Japanese Patent Application Laid-open No. 62-41698 and the like. The dryers disclosed in these publications have a configuration in which the supply and exhaust temperatures of the drying chamber are measured at the beginning of the drying process, and the remaining drying time is estimated and displayed based on the temporal change in the temperature difference, that is, the rate of temperature change. It is shown.

(c) Problems to be Solved by the Invention However, when the dryer is operated continuously, residual heat from the previous operation remains in the rotating drum in the drying chamber during the second and subsequent operations. As a result, there is a high possibility that an error will occur in the rate of temperature change, and the estimated remaining time may also include an error.

This invention has been made in consideration of the above circumstances, and is therefore a dryer that estimates the remaining time by determining the load of clothes, etc. to be dried from the starting current of the motor for driving the rotating drum and the rate of temperature change. Party B intends to provide a control device for this purpose.

(d) Means for Solving the Problems As shown in FIG. 1, the present invention detects the starting current of a motor 100 that rotates a rotating drum in a drying chamber when drying of an object to be dried starts. Current detection means 10
1, a first determination means 102 that determines the first load constant from the starting current detected by the current detection means 101, a temperature detection means +03 that detects the exhaust temperature from the drying chamber, and a temperature detected by the temperature detection means +03. calculation means 104 for calculating the temperature increase rate after a predetermined period of time from the start of drying of the exhaust gas temperature;
and a second determining means 105 that determines a second load constant from the temperature increase rate calculated by the calculating means 104, and a second determining means 105 that determines the second load constant from the first and second load constants determined by the respective determining means 102 and 105. This is a control device for a dryer comprising: time determining means +06 for determining a remaining drying time corresponding to the amount of drying time.

(Po) Effect In the above configuration, the current detection means +01 detects the starting current of the motor 100 at that time when drying operation is started. The value of the detected starting current is input to the first determining means 102, and the first determining means 102 determines a first load constant corresponding to the amount of material to be dried in the rotating drum, that is, the load amount, from the value, It is output to the time determining means 106.

The temperature detection means 103 detects the temperature of the exhaust gas from the drying chamber after the start of drying. The value of the detected exhaust gas temperature is input to the calculation means 104, and the calculation means 104 calculates the rate of temperature increase after a predetermined time from the start of drying from the value.

The calculated temperature increase rate is input to the second determination means 105, and the second determination means 105 determines a second load constant corresponding to the load amount from the temperature increase rate and outputs it to the time determination means 106.

The time determining means 106 determines the remaining drying time corresponding to the load amount by combining the input first and second load constants.

Therefore, in addition to determining the magnitude of the load from the value of the starting current, it is also possible to determine the magnitude of the load from the temperature rise rate.
Since the remaining drying time is determined by finally determining the load amount by combining these determination results, it is possible to reduce the error in the remaining drying time.

(F) EXAMPLES Hereinafter, examples of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to the following examples.

In Fig. 2, TI is a current transformer, and its primary winding is connected in series with switch SW1, and connected in series with thyristors THI and TH2, which respectively control the energization of motor M and heater H. Connected. The secondary winding of the current transformer TI includes a rectifier circuit 1 consisting of resistors R1, R2, a diode D1, and a capacitor CI.
is connected. The cathode of diode D1 is connected to one input terminal of comparator COMI. The other input terminal of the comparator COtvl l is connected to the output terminal of a D/A conversion circuit 2 that converts a digital signal from a microcomputer (hereinafter referred to as microcomputer) IC1 into an analog voltage.

A comparator C is further connected to the output terminal of the D/A conversion circuit 2.
0M2 and one input terminal of comparator C0M3 are connected. At the other input end of the comparator C0M2, there is a temperature sensor 3 that detects the temperature of the exhaust air from the drying chamber, and at the other input end of the comparator COM3, there is a temperature sensor 4 that detects the temperature of the intake air into the drying chamber. are connected to each other. Respective comparators COM 2 , COM 3
The other input terminal of is pulled up by resistors R3 and R4.

and each comparator C0IVII C0M
2. The output end of C0M3 is connected to the input port of the microcomputer ICI.

The microcomputer ICI is a ROM that stores in advance a control program and a data table for determining load amount.

It has a RAM, a CPU, and an input/output section in which the values of the starting current of the motor M are stored, including temperature sensors 3 and 4 and a comparator COMI.

FIG. 3 is a longitudinal cross-sectional view showing the structure of the dryer H incorporating this embodiment.

In the figure, 5 is a drying chamber, 6 is a rotating tram, 7 is a heat exchange type double-sided fan, and 8 is a duct for circulating air for drying.

Next, the operation of this embodiment will be explained with reference to FIGS. 4 to 7.

FIG. 4 shows each temperature sensor 3. - It is a graph showing the temporal change in temperature detected by 1.

In this case, the temperature change rate of exhaust air, ij, and degrees during the preliminary drying period, that is, the predetermined time after the start of drying, or the standard value Δ
It is stored in the ROM of the microcomputer tCI as Ts.

Similarly, the value of the starting current of the motor M when drying the amount of material to be dried that becomes floating is stored in the ROM of the microcomputer ICI as a standard value 8.

FIG. 5 is a flowchart showing the operation of this embodiment.

When the material to be dried is put into the rotating drum 6 and drying is started, the starting current 8 of the motor M is measured (step Sl). As shown in FIG. 6, the starting current I9 of the motor M increases as the amount of material to be dried in the rotating drum 6, that is, the load amount increases.

The starting current I8 of the motor M is detected by the current transformer TI. Corresponding to this starting current (4), a voltage V1 is input from the rectifier circuit 1 to the comparator COM1. Comparator COMI compares reference voltage Vc output from D/A conversion circuit 2 with voltage v8. The comparison result is input to the microcomputer ICI, and the microcomputer ICI measures the starting current (9) based on the result.

When the starting current I is measured, the microcomputer ICI determines whether the measured starting current I is smaller than 09 times the standard value 5 (step S2).

If the result is small, the amount of material to be dried, that is, the load amount, is determined to be small, and the first load constant A=1 is determined (step S3).
. On the contrary, if it is determined in step S2 that it is larger, the microcomputer ICI will increase the starting current by 1 s from 11 times the standard value.
+ or smaller is determined (step S4). If it is not determined in step S4 that the load is small, the load is medium and the first load constant A=2 is determined (step S5); if it is determined to be large, the load is large and the first load constant is 8. -3 (step 56) 5 These first load constants A are stored in advance in the ROM in the microcomputer IC1 according to the conditions.
is stored in

When the first load constant A is determined as described above, it is determined whether the load amount LA is due to the motor starting current (step S7
), the first load constant A determined correspondingly or R, A M +, in the microcomputer ICI is stored.

Next, start drying. Hours later. The exhaust gas temperature after ↓△ time is measured (steps S8 and S9).
. As shown in FIG. 7, the exhaust temperature decreases as the load increases, and is smaller than the temperature change rate at the initial stage of drying.

When the temperature sensor 3 detects the exhaust temperature from the drying chamber 5,
v8 is inputted from the temperature sensor 3 to the comparator C0M2. At this time, the microcomputer ICI outputs digital data to the D/A conversion circuit 2, and the D/A conversion circuit 2 outputs the reference voltage Vc to the comparator COM2.

The comparator COM 2 receives the input vll and the reference voltage V. and outputs the result to the microcomputer ICI. The microcomputer ICI determines the exhaust temperature T based on the results. , measure TI.

The microcomputer ICI measures the measured exhaust gas temperature T. , calculate the temperature change rate α at time Δt from TI (step 5I
O).

After the temperature change rate α is calculated, the microcomputer IC1 determines whether the temperature change rate α is smaller than 0.9 times the standard value ΔTs (step Stl). If the result is small, the load amount is determined to be small and the second load constant B=1 is determined (step 5I2). On the contrary, if step Sll is determined to be large, the microcomputer ICI determines whether the temperature change rate α is smaller than 1.1 times the standard value ΔTS (
Step 513). If the result is small, the load amount is determined to be medium and the second load constant B=2 is determined (step 514).

On the contrary, if it is determined in step S13 that the load is large, the load amount is increased and a second load constant B-3 is determined (step 5I5). These second load constants B and the determination conditions are stored in advance in the ROM in the microcomputer IcI.

When the second load constant B is determined as described above, the load amount LB based on the temperature change rate is determined (step 516).
, the second negative constant B determined correspondingly is the microcomputer I
Store in RAM in C1.

After this, the final load amount is determined from the combination of the first load constant A and the second load constant B, which are not stored in the RAM (steps SI7 to SI524). That is, if it is a combination of A=I and B=1, the amount of load is assumed to be minimal, and the corresponding constant C is determined to be 08 (step 525).

Next, if A=IB=2 or A=2.8=l, the load amount is medium and the constant C is set as 09 (step S26.527). Mat=, A=1. B=3, A2,
B=2 or A=3. If B=1, it is assumed that the load amount is medium, and the constant C is set to 1 (step S28.
29.530). Furthermore, A=2B=3 or A=3.
If B=2, the load is large, and the constant C is set to 1.
．． 1 (steps S31, 532). A=3. B
= 3, the load amount is maximum, and the constant C is 1
．． 2 (step 533).

Thereafter, a constant C is determined based on the determinations in steps S17 to S33 (step 534), and the microcomputer ICI calculates and determines the remaining drying time by multiplying the determined constant C by the standard time. (Step 535).

Note that the remaining drying time may be determined based on the rate of change in the temperature of the exhaust gas from the drying chamber and the value of the heater current.

In the dryer shown in FIG. 8, the air heated by the heater 11 evaporates the water contained in the clothes in the rotating drum 12, and then is blown by the inner surface of the heat exchange type double-sided fan 13. Air is taken in from inside the rotating drum 12 and passed through the duct 14.
The air is again blown through the heater II. Furthermore, the flow of air inside the dryer is represented by a black arrow Ab, and the flow of outside air is represented by a white arrow AW.

In the figure, 15 is a filter, 16 is a temperature sensor provided on the exit side of the drying chamber 17, and 18 is a temperature sensor provided on the population side.

FIG. 9 shows changes in temperature differences between the temperature sensors 16 and 18 during the drying process. In the figure, the horizontal axis represents the elapsed drying time, and the drying ends after a preliminary drying period, a constant rate drying period, and a decreasing rate drying period. After the start of operation, the temperature is sequentially detected by the temperature sensor I6 during the pre-drying period, the slope of the temporal change, that is, the rate of temperature change is determined, and the load amount is indirectly determined based on this value.

FIG. 1O shows changes in the temperature detected by the temperature sensor 16 depending on the load amount or the type of clothing. Here, the load amount is CI
The number increases in the order of <C2<C3. The raw coal characteristics CI and the temperature characteristics C3 at the rated load are almost the same, but due to the difference in the amount of water that evaporates, the constant rate drying period is shorter when the load is small.

Next, a schematic circuit diagram is shown in FIG. Each temperature sensor 16
．． The voltage value detected at 18 is input to the microcomputer 21 via the A/D conversion circuit 20.

In addition, various lamps (light emitting diodes) LEDs are equipped with switches SW, and the fan drive motor 22 and heaters lla and llb are used as loads.
It is controlled via 5. Further, the heater current is detected by a transformer Tr provided on the load side, and inputted to the microcomputer 21 after A/D conversion.

Next, the operation will be explained based on the relationship between filter clogging and heater current shown in FIG. 12 and the flowchart shown in FIG. 13.

First, in FIG. 12, Sa is a standard value (heater current flowing during normal operation) and Ll is a lower limit value (heater current when the flowchart is clogged and drying does not proceed). When the heater current is measured at a certain temperature (e.g. 20°C), it either shows a value near the standard value Sa, or if clogging occurs, the value gradually decreases as shown in the figure, and if left unattended, it will reach the final value. It ends up reaching the lower limit Ll.

Near the lower limit value Ll, the amount of airflow decreases due to clogging and the amount of heat generated by heater II decreases, resulting in a decrease in thermal efficiency and a state where only drying is possible.

Here, in the conventional technology, even if f2 heater current is measured, it is always less than the standard value Sa, and the drying time (remaining time) is the same as when the standard value Sa is used, so the error increases and the drying There are variations in the finished state. Therefore, after measuring the heater current, it is necessary to find the difference from the standard value, change the set time based on the difference, and correct the remaining time.

Hereinafter, referring to the flowchart of FIG. 13, the microcomputer 12 clears the lamp area in step 54.
0), the key-ON input data is read (step 541), and the set time is determined. Thereafter, each key manually turns on a predetermined lamp (step 542), and the heater 1
1 and the motor 22 (step 543), and a drying operation is performed. Then, the heater current is measured (step 544), and if the values are similar (step 545), it is determined that the filter is not clogged (step 846), and the drum exit and inlet temperatures are detected (step 545). 547), and calculate the temporal change in drum outlet temperature (step 548).

Thereafter, the set time is changed in accordance with the calculated temporal change (step 549), the remaining time is displayed (step 550), and the drying operation is continued during the remaining time (step 551).

On the other hand, if it is determined in step S45 that the heater current is less than the standard value, it is determined that the heater current is about to become clogged (step 552), the difference between that value and the standard value is calculated, and the difference is within the set range (for example, 5a-L1 in Fig. 12), and if it is within the range, the preset drying time is changed step by step (step 554), and the In addition to the set time due to changes in the drying temperature, corrections are made to determine the required drying time and the remaining time is displayed.

If the difference is outside the set range, it is compared with the lower limit L1 (step 553), and if it is below the lower limit, a clogging alarm is issued (step S56), and the operation is stopped.

If it is above the lower limit, after a 10 second delay (step 55)
7), which measures the temperature.

After step S51, it is determined whether the set time changed in step S49 has been reached (step 858), and if the set time has elapsed, the heater 11 is turned to 0FFL (step 559), and the motor 22 continues to be energized for a predetermined time. Cool down is performed (step 560), and then the motor 22 is turned off (step 561).

The operation for determining the remaining drying time will be further explained in detail with reference to FIGS. 14, 8 and B.

First, when the operation is started, the temperature sensor 16 determines the initial temperature T of the exhaust gas temperature. ' is measured (step 570). Measure the exhaust temperature T, ° after one minute (step 5).
71) Temperature T of each of the 6th measurement points. ”, Tr” and calculate the temporal temperature change (hereinafter referred to as slope) α°
(step 572).

The slope α° thus obtained is compared with 09 times the standard value (step 573), and if the slope α is small, the load amount LA
'-1 (step 574); otherwise, they are compared with a value 11 times the standard value (step 575), and the load amount LA'-2 and load amount LA'-3 are determined, respectively (step 876. 877).

Next, based on the determined load amount t, 4', the load amount LA' due to temperature change is determined (step 578).

After step S78, the heater current [is measured] (step 579). Then, the measured heater current ■ is compared with a standard value or a lower limit value (step S80.581). As a result of each comparison, if the heater current I is larger than the standard value, it is assumed that the filter is normal, and the drying time constant B'-
1 (step 82); if it is greater than the lower limit, it is determined that the filter is in progress, and a constant B"-2 is determined (step 583). On the other hand, if the heater current is smaller than the lower limit 1, step 82) , an abnormality is displayed to notify of clogging) (step 584), and the operation is stopped.

When it is determined in steps S82 and 883 whether the constant B' is present, the drying time using the heater current is determined based on it (step 585).

Thereafter, the combination of the load amount LA' determined in step S78 and the drying time constant B' determined in step S85 is determined in step S87. , S88. S
89,590), and the value of constant C' for changing the set time by 4 is determined from the determination result (Snap S91
S92 S93 S94, S95.596).

Then, based on the determination result, the value of the constant C° is determined (step 597), and the drying time D′ is determined by multiplying by the constant C′ of the Iffff opening time (step 598).

With the above configuration, uneven drying of the dried material due to filter clogging can be prevented, and the remaining drying time can be accurately determined.

In these dryers, the temperature sensor for detecting the temperature of the exhaust gas may be made of a water-absorbing material, such as a sponge.

That is, thin clothing such as sheets and diapers may become entangled in a ball or spiral shape. This creates a large space inside the rotating drum, and most of the air that enters the rotating tram escapes through that space and exits to the outside. As a result, the temperature of the exhaust gas from the rotating drum increases, and the microcomputer may determine that drying is complete and stop operation. For this reason, variations occur in the dry finish state. Therefore, by covering the temperature sensor installed at the outlet side of the rotating drum with a water-absorbing material, the water that evaporates from the clothes will be adsorbed to this area, and during the careful drying period, the temperature difference between the temperature sensors can be absorbed by the microcomputer. During the decreasing rate drying period, in which the amount of adsorbed water decreases as drying progresses, the water in the water-absorbing material (sponge) is evaporated by the hot air, and the heater, inlet, and rotating drum outlet are It can be determined that drying is complete by detecting that the temperature difference begins to change rapidly.

Roughly speaking, if the clothes contain sufficient moisture, most of the thermal energy obtained from the clothes drying air or heater will be used as the latent heat of vaporization contained in the clothes. but,
As drying progresses and the moisture content in the clothes decreases, the amount of latent heat of vaporization gradually decreases, so the temperature of the clothes drying air discharged from the rotating drum begins to rise gradually.

Drying control becomes possible by detecting this temperature rise using a temperature sensor.

Therefore, when the amount of clothing is large and the moisture content is sufficient, as shown in FIG. 15, the above-mentioned temperature rise will be greater, and the detection accuracy of dried leaves will also be higher.

In the figure, PA is a pre-drying period during which the temperature inside the drum increases, PB is a constant rate drying period where the drying rate is constant, and PC is a decreasing rate drying period during which the drying rate of the entire garment decreases. However, for thin clothing such as sheets, or when the load is small, the temperature characteristics will not be as shown in FIG. 15, but will be as shown in FIG. 16. This is because the constant rate drying period PB' is shorter when the load is small due to the difference in the amount of water to be evaporated. In addition, the air heated by the heater for drying clothes is
Since the sheets and the like are in a spiral or lumpy state, they are often exhausted without being efficient, so the exhaust temperature pulsates as shown in Figure 16, making accurate detection impossible. become.

After this, the temperature sensor provided on the outlet side of the rotating drum is covered with a water-absorbing substance (water-absorbing material), and the moisture evaporated from the clothing is adsorbed to this part. This suppresses variations in the detected temperature during the constant rate drying period PB'. The temperature difference between the heater inlet temperatures is stored in the microcomputer, and the moisture in the water-absorbing material is evaporated by hot air during the lapse rate drying period, and the temperature difference between the temperature sensors changes rapidly. It improves the condition.

By configuring as described above, it is possible to obtain a highly efficient dryer by suppressing variations in the finished drying state that occur when drying thin clothes such as sheets or when using a small load, and drying evenly.

(g) Effects of the Invention According to this invention, the load amount is determined by detecting both the motor starting current and the temperature change rate of the exhaust gas temperature from the drying chamber, and the remaining drying time is determined based on that. , it is possible to improve its accuracy.

[BRIEF DESCRIPTION OF THE DRAWINGS] Fig. 1 is a block diagram clearly showing the structure of the present invention, Fig. 2 is an electric circuit diagram showing the structure of an embodiment of the invention, and Fig. 3 is a dryer in which the embodiment is used. 4th longitudinal sectional view showing the configuration of
The figure shows the detected temperature/degree characteristics of the temperature sensor in the example, Figure 5 is a flowchart explaining the operation of the example, Figure 6 is a graph showing the motor starting current characteristics in the example, and Figure 7 is the actual example. In the example, a graph showing the detected temperature characteristics of the temperature sensor depending on the difference in load amount, Fig. 8 is a configuration explanatory diagram showing the sales channel structure of another dryer, and Fig. 9 shows the temperature sensor in the dryer shown in Fig. 8. Graph showing detected temperature characteristics, 10th
The figure is a graph showing the detected temperature characteristics of the temperature sensor 16 in Fig. 9 for each load, Fig. 11 is an electrical control circuit diagram of the dryer shown in Fig. 8, and Fig. 12 shows the heater current characteristics in drying K in Fig. 8. The graphs shown in FIGS. 13 and 14 are a flowchart explaining the operation of the dryer shown in FIG.
Figure 5 is a graph showing the detected temperature characteristics of the temperature sensor when the amount of material to be dried is large and the moisture content is sufficient, and Figure 16 is a graph showing the change in exhaust temperature when the material to be dried becomes a lump. It is a graph. 00 02 +03... +04 105 ・+06・ ・Motor, 101 ・Current detection means, first judgment means, temperature detection means, ・Calculation means, second judgment means, time determination means. (○.) i Xi Qiangmu = Td 澍; 小法 (○.) 匍-) Iming渁渁 こ U - SA-BE E℃] 16th 15th Zuikyu, 89M [Morning □□□□ -Col ”I momentary drunkenness

Claims (1)

[Scope of Claims] 1. Current detection means for detecting a starting current of a motor that rotationally drives a rotating drum in a drying chamber at the start of drying of an object to be dried; and a first load constant determined from the starting current detected by the current detecting means. a first determination means for determining the temperature of the exhaust gas from the drying chamber; a calculation means for calculating the temperature increase rate after a predetermined period of time from the start of drying of the exhaust temperature detected by the temperature detection means; a second determination means for determining a second load constant from the temperature increase rate calculated by the calculation means; and a remaining drying time corresponding to the amount of the material to be dried from the first and second load constants determined by the respective determination means. A dryer control device comprising: time determining means for determining;