JPH0552236B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Field of Industrial Application The present invention relates to a washing machine that executes washing, rinsing, and other processes depending on the amount of laundry by driving a motor. (b) Prior art It is important for this type of washing machine to accurately detect the amount of laundry. Conventionally, there have been methods for detecting the amount of laundry based on changes in the current of the motor that drives the rotary blades of the washing machine, or A detection method based on changes in motor rotation speed has been proposed. These methods reduce the load on the rotor when the amount of laundry increases.
That is, it takes advantage of the fact that the motor load increases, the motor current increases, and the rotational speed decreases. For example, according to Japanese Patent Application Laid-Open No. 132366/1983, the current value is measured after a certain period of time after the motor is started during the washing process, and when the amount of laundry is large, the current value is high, and when there is little Due to the relationship that its value is small,
A method is adopted in which the measured current value is compared with a value stored in advance in a time setting device, and the execution time of the washing process is determined based on the comparison result. Furthermore, according to Japanese Patent Application Laid-Open No. 59-125598, instantaneous fluctuations in motor current are proportional to the amount of laundry, so the amount of laundry can be determined by detecting the instantaneous current changes and comparing them. A method is used to determine the amount of water used for washing, the washing time, the amount of detergent, etc. However, in the former case, the range of change in motor current is very small compared to the total current, and it is difficult to judge the amount of laundry only based on the measured current value, depending on the variation in the motor used, the capacitance of the capacitor, the movement of the laundry in contact with the rotary blades, etc. It was difficult to do. In addition, in the latter case, instantaneous fluctuations in the amount of laundry in contact with the rotor blades will cause variations in the measured values depending on the water level, and sometimes the measured values will have opposite results depending on the amount of laundry. It was hot. (c) Problems to be Solved by the Invention The present invention aims to obtain a clear current measurement value corresponding to the amount and type of laundry, and to implement process control appropriate to the laundry. (d) Means for Solving the Problems The washing machine of the present invention drives a motor to perform predetermined washing, and includes current detection means for detecting a predetermined current when the motor is driven. and,
an integrating means for integrating the current detected by the current detecting means in order to convert it into an electrical quantity; a driving means for driving the integrating means a plurality of times within a predetermined time; and a plurality of integrated outputs of the integrating means by driving the driving means. quantity determining means for determining the amount of laundry based on the average value of the amount of laundry, type determining means for determining the type of laundry based on the width of dispersion of the plurality of integrated outputs, and determination by the amount determining means and the type determining means. and control means for driving and controlling the motor based on the results. (e) Effect: That is, a plurality of integrated outputs are extracted, and the amount of laundry is determined based on the average value thereof, and the type of laundry is determined based on the maximum and minimum variations in the integrated outputs. For example, the output characteristics of cotton and chemical fibers are shown in Figure 4. Cotton absorbs water, becomes heavy, tends to sink, and has strong contact with the rotor, but the opposite is true for synthetic fibers, so cotton Even if the output is the same for 1 kg and 2 kg of synthetic fiber, the width of the output variation is different. In other words, in terms of output characteristics, the width of the variation in output is large for cotton and small for synthetic fibers. (f) Example The control circuit diagram in Figure 1 and the cross-sectional view in Figure 2 include the following:
A fully automatic washing machine 2 is shown that sequentially executes washing, rinsing, and spin-drying steps based on the control output of a microcomputer (hereinafter referred to as microcomputer) 1. By closing the power switch 3 and operating the start switch, the microcomputer 1 opens the water supply solenoid valve 4 interposed in the water supply channel, supplies water to the outer tank 5 or the dewatering/washing tub 6, and starts the washing process. . An air trap 7 is provided in the outer tank 5, and when the water supply level rises to a predetermined value, the pressure at that time trips a diaphragm-type water level switch 8 (ON).
Then, the water level signal is input to the microcomputer 1. still,
The water level switch 8 is of a type that has a predetermined difference between the trip water level and the reset water level, and can set the water level in several stages. In this manner, the microcomputer 1 closes the water supply solenoid valve 4 using its control output, and at the same time sends a clockwise rotation signal (Fig. 3a) to the capacitor run type single-phase induction motor 9 after a certain rest time ) and a counterclockwise rotation signal (see Fig. 3b) are output alternately. This rotation signal is output for a very short period of time from about 0.7 seconds to about 2 seconds, and is output eight times on each side during one cycle of 23 seconds. The rotation of the motor 9 is controlled by large and small pulleys 10, 10.
A large-diameter chevron-shaped rotary blade 12 is firstly decelerated by the belt 11 and then secondarily decelerated by a deceleration means (not shown) using a planetary gear mechanism, and is located in the dewatering/washing tub 6. transmitted to. Therefore, the rotor blades 12 rotate left and right alternately at low speed to create a water flow,
It also stirs the laundry, thereby washing the laundry. A large number of dehydration holes 13 are bored in the wall of the dehydration/washing tub 6, and an annular balancer 14 filled with liquid is attached to the upper periphery. A drain port is provided at the bottom of the outer tank 5, and a drain solenoid valve 15, which is opened and closed as appropriate by the control output of the microcomputer 1, is interposed in the drain channel. Further, the outer bottom of the outer tank 5 is provided with a clutch mechanism that transmits the primary deceleration rotation of the motor 9 to the dehydration tank shaft 16 during dehydration, and a mechanism that applies a brake to the dehydration tank shaft 16 at the end of dewatering. These are indicated by reference numeral 17. The total time during which the rotary blades 12 are rotated during the washing process is appropriately determined each time depending on the amount (load amount) of laundry loaded into the washing tub 6 and the type of laundry. During the subsequent rinsing process, drain solenoid valve 1
5 is opened to drain the water, the water is drained to a very low water level, and when the water level switch 8 is reset (OFF), the motor 9 is continuously rotated in one direction to start dewatering. During this dehydration, the dehydration/washing tub 6 is rotated together with the dehydration tank shaft 16 by the clutch mechanism.
Further, in synchronization with this rotation, the rotor blade 12 also rotates in the same direction and at the same speed. When this dehydration is completed, the drain electromagnetic valve 15 is closed, and a process similar to the above-mentioned washing process is performed. This rinsing process is normally performed twice, and once if necessary.
times are omitted. Further, if necessary, water can be supplied continuously or intermittently while the rotary blade 12 is being reversed after water supply is completed. In the rinsing process, the total time for rotating the rotary blade 12 and the total time for rotating the dehydration tub shaft 16 and washing tub 6 are similarly determined each time depending on the amount of laundry and the like. The subsequent dewatering step (final) is a series of operations of draining and dewatering in the rinsing step described above, and the dewatering time is longer. This longer dehydration time is determined on a case-by-case basis depending on the amount of laundry, etc. Although the dewatering process is completed by applying the brake, the power to the motor 9 is cut off before applying the brake to suppress the shock and the brake noise generated when the brake is applied. In order to keep the brake application substantially constant regardless of changes in the amount of laundry, etc., the time point at which the motor is turned off is varied depending on the amount of laundry, etc. In this way, the various times of the process are determined according to the amount of laundry, etc., and the output signals from the microcomputer 1 control the motor 9, the water supply and drainage solenoid valves 4 and 15, the clutch/brake mechanism, the buzzer, etc. The system controls the driving elements of the engine and executes extremely appropriate stroke control. Next, to explain the detection of the amount and type of laundry and the subsequent control, as shown in FIG. ₁ , a current transformer ( Below is CT ₂ )1
8, and a current transformer (hereinafter referred to as CT ₁ ) 21 is provided as means for detecting the current (A ₁ ) of a capacitor 20 connected between the windings 19 and 19. Load resistors 22, 22 are connected to these CT ₁ , 21 and CT ₂ , 18, respectively, and the current detected here is rectified by diodes 23, 23, and is connected to resistors 24, 24 and capacitors 25, 25.
The output signal is smoothed by , resulting in the output signal shown in FIG. 3d. When the motor is started, a charging current flows through CT ₁ and 21, and a starting current flows through CT ₂ and 18, so microcomputer 1 outputs a starting cutoff signal (see Figure 3 c) in synchronization with the left and right rotation signal of the motor. do. This activation cutoff signal causes transistors 26, 26 to sense the steady state current in the output signal. The resulting output signal waveform is shown in Figure 3e. As a result of inputting this output signal to the differential amplifier 27 and determining the difference, a difference signal based on the current difference shown in FIG. 3f is obtained. This difference signal is proportional to the amount of laundry and is input to the adder 28. Here, since the capacitor current (A ₁ ) largely depends on fluctuations in current and voltage, compensation for fluctuations is required. First, the power supply voltage is stepped down by the transformer 29, rectified and smoothed to create a DC voltage (V _ref ) proportional to the power supply voltage, and this DC voltage (V _ref ) is synchronized with the left and right rotation signal of the motor 9. hand,
It is also controlled by a transistor 30 that receives a start-up cutoff signal and is input to an inverting amplifier 31 . When the inverting amplifier 31 receives a DC voltage (V _ref ) proportional to the power supply voltage, it outputs a compensation signal corrected to an appropriate voltage corresponding to the voltage, and inputs it to the adder 28 . These compensated difference signals are output every time the left and right rotation signals are output, but since the output time of the rotation signal is extremely short, the output time of the left and right rotation signals is different, and each time From changing, 1
There is a large error in just the effective voltage value (peak value) of the signal. Therefore, when a total of 16 signals are output in one cycle, eight times on each side, as shown in FIG. be done. The integrating circuit 32 includes an integrating amplifier 33, a capacitor 34, a resistor 35, and a photocoupler 36. In addition, photocoupler 3
6 may be replaced with an analog switch, relay, etc. Here, the microcomputer 1 turns off the photocoupler 36 with a reset signal when the motor starts rotating.
Then, the capacitor 34 is charged. And 1
When the cycle of operation is completed, the microcomputer 1 turns on the photocoupler 36 with a set signal and turns on the resistor 35.
discharge to. That is, the integration circuit 32 converts the output signal for one cycle into "peak value x rotation time", that is, an electrical quantity. This integrated output (see FIG. 3g) is input to a differential amplifier 37 as a level shifter. The above difference signal shows different wave height values when loaded with laundry and water, when loaded with water only, and when no load is loaded. Here, subtract the difference signal at the time of water load or no load from the difference signal at the time of load,
Extracts the output generated only by the laundry placed in the tub. For this purpose, the bias voltage (V _B ) of the differential amplifier 37 is adjusted by the variable resistor 38 so that the output when water is loaded or when there is no load is set to be zero or close to it. For example, the third
Adjust and set so that the integral output at the time of water load shown in the figure h is subtracted from the integral output shown in the figure g. As a result, only the output increased by the laundry (see FIG. 3 i) is appropriately amplified and extracted from the differential amplifier 37. Variations caused by variations in the electromechanical system, such as, are removed at this point.
Incidentally, these operations for extracting the increased output can also be carried out for each smoothed output signal after the startup cut-off shown in FIG. 3e. In this case, the third
As shown in Figure j, if the smoothed output is v1 at no load, v2 at water load, and v3 at load, then the bias voltage (V _B ) shown in Figure 3 k is the output at no load or at water load. Set according to the output, and increase the output Δv1 (｜v3−v2｜) and Δv2 (｜v3−
v1｜) is extracted. Thus, the differential amplifier 37 shown in FIG.
The negative output of the integrated output from the microcomputer 1 is cut off by the diode 39 and inputted to the comparator 40 as an output shown in FIG. This comparison signal is input from a D/A converter 41 including a ladder network via an input buffer 42, and the microcomputer 1 reads the comparator output. The microcomputer 1 turns the photocoupler 36 ON and OFF in each operation cycle, compares and reads the integrated output each time, and here, for example, reads the output six times consecutively from the start. Then, the six outputs are averaged to calculate an average value, and the range of variation between the maximum integrated output (V _MAX ) and the minimum integrated output (V _MIN ) is calculated. Microcomputer 1 is based on the relationship between the amount of laundry and the average value of output, the relationship between the type of laundry (fiber type) and the maximum and minimum variation width of output, and the amount and type of laundry, which have been determined as standard through experiments. The relationship between each stroke time and each work time during the stroke is stored in advance, and each driving element is driven on time according to the amount and type based on the calculated average value and variation range, and the stroke progresses. will be controlled. Incidentally, the following table shows the spin-drying time set for each type and amount of laundry in the final spin-drying process. still,
By dehydrating in this time, you can reduce the amount of laundry and
Appropriate dehydration rates were obtained depending on the type.

[Table] In this example, the difference between the capacitor current (A ₁ ) and the line current (A ₂ ) of the motor 9 was used as the control value.
This is because, as shown in FIG. 5, the current difference is hardly affected by changes in the capacitance of the capacitor 20, and output fluctuations due to this variation can be eliminated. However, if the capacitor 20 has high precision and almost no variation, CT ₁ and 21 and the related circuit configuration are not necessary. At this time, only the line current (A ₂ ) is rectified, smoothed, and power supply compensated.
The results are integrated and the integrated outputs are compared six times. In this case, the operation of extracting the increased output by the differential amplifier 37 is performed on the smoothed output or the integrated output. Feedback resistors R1, 43 and R2, 44 are switchably connected to the inverting amplifier 31 and the differential amplifier 37, respectively. The resistance value of resistor R1, 43 is changed to resistor R2, 4
It is 5/6 of that of 4. This feedback resistance R1,
By switching R2, 43, and 44, the gain constant changes and can be used when the power supply frequency changes between 50Hz and 60Hz. That is, in the case of 60Hz, resistor R1, 43
In the case of 50Hz, if you switch to resistor R2, 44,
The output for the same amount of laundry is the same regardless of the frequency. Switching operations for both amplifiers can be performed centrally, and resistors R1 and R2 are
It can also be replaced with a variable resistor. Next, the overload condition on the motor 9 and the motor 9
The control operation in the locked state will be explained. The normal integrated output is specifically about 4V, and this output, a large predetermined value of 10V or more (V _UL ), and an overload value of about 5V (V _OL ) are stored in the microcontroller 1 in advance. be. As shown in Fig. 6, when the washing process starts and the detection operation of load amount etc. starts, the integrated output for each operation cycle is compared with (V _UL ), and if it is above (V _UL ), the motor 9 is activated. The lock state is notified and displayed with a buzzer, etc. If (V _UL ) is not exceeded, the average value of the six integrated outputs is calculated, and this is sequentially compared with (V _UL ) (V _OL ).
If it is above (V _UL ), the motor 9 is stopped as described above to indicate that it is locked, and if it is below (V _UL ) and above (V _OL ), it indicates whether the water level setting at this time is a high water level. If the water level is high, it performs the same operation as locking. If the water level is not high, the water level setting will be automatically changed to high water level, the water supply solenoid valve 4 will be opened, water will be supplied, the first six integration outputs and the average value will be cleared, and the above operation will be performed again. Repeat. If the water level has not been set appropriately for the amount of laundry, it is possible to escape from the overload state by supplying (replenishing) water in this way. In addition, if the average value is less than (V _OL ), the time for each process and the working time during the process are determined based on the average value and the range of variation in the integrated output, and the laundry is damaged during this time. Control the progress without any effort. (G) Effects of the Invention According to the present invention, a plurality of integrated outputs (electrical quantities) are used as standards for detecting the amount of laundry, etc., and the amount and type are determined based on the average value and the width of variation of the integrated outputs. It is possible to perform highly accurate stroke control by improving detection performance.

[Brief explanation of the drawing]

Fig. 1 is a control circuit diagram of a washing machine according to the present invention, Fig. 2 is a sectional view, Fig. 3 a to m are output waveform diagrams at each part of the control circuit diagram, and Fig. 4 is an output according to the amount and type of laundry. FIG. 5 is a characteristic diagram of the current difference with respect to the amount of laundry, and FIG. 6 is a flowchart illustrating the control operation in the event of overload or motor lock. 1...Microcomputer (means for driving the integration means,
(determination means, motor drive means), 9...motor,
18, 21...Current transformer (current detection means), 32...Integration circuit (integration means), 37...Differential amplifier (means for extracting an output increase).

Claims (1)

[Claims] 1. In a device that drives a motor to perform a specified amount of washing, a current detection means for detecting a specified current when the motor is driven, and an integration device for converting the detected current by the current detection means into an electrical quantity. a driving means for driving the integrating means a plurality of times within a predetermined time; and an amount determining means for determining the amount of laundry based on the average value of a plurality of integrated outputs of the integrating means driven by the driving means. , comprising a type determining means for determining the type of laundry based on the width of variation in the plurality of integral outputs, and a control means for driving and controlling the motor based on the determination results of the amount determining means and the type determining means. A washing machine characterized by: