JPS60119994A - Clothing dryer - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a drum-type clothes dryer for use in general households.

(Conventional structure and its problems) Conventionally, clothes dryers have a structure in which the drying completion time varies greatly depending on the amount of clothes to be dried. The method used was to estimate the drying end time and set the drying time using the timer attached to the aircraft. But with this method,
Even if the clothes are actually already dry, you may end up wasting electricity until the set timer time expires, causing overdrying and damaging the clothes, or setting the timer too short. There are problems such as the need to take the time and effort to reset the settings if the settings are correct.

To solve this problem, a drying end sensor has been developed in recent years, and models that can finish drying in conditions close to optimal drying are now on the market. This method is unclear and is extremely difficult to handle, such as setting up the next washing/drying process.Furthermore, when there is only a small amount of fabric, the temperature inside the drum rises too much, damaging the fabric, which has not been resolved at all. .

As a solution to this problem, it is necessary to determine the amount of material to be dried at the start of drying, automatically estimate the drying end time, and to vary the power of the heater according to the amount of material to be dried. One possible method for this is to determine the amount of material to be dried based on the temperature rise rate of the drum internal temperature or exhaust temperature (see Figure 1). There was a drawback that it was impossible to make a determination at all if the temperature inside the drum had risen completely. Another problem with this method is that when drying a small amount of material to be dried, the temperature inside the drum rises too much while determining the amount of material to be dried, which may damage clothes.

(Objective of the Invention) The present invention solves the problems that conventional clothes dryers have, by accurately determining the amount of items to be dried,
It is an object of the present invention to provide a clothes dryer that can always carry out appropriate control according to the amount of items to be dried.

(Structure of the Invention) To achieve this object, the clothes dryer of the present invention includes a drum for accommodating and stirring a load, a heater and a fan for blowing hot air into the drum, and a rotary drive for driving the drum. a control circuit that controls the heater, the fan, and the motor individually or collectively; and a load that detects the amount of load based on a change in the characteristics of both or either of the current and voltage applied to the motor. and a load amount detection circuit, and the control circuit controls the heater, fan, or motor based on a signal from the load amount detection circuit.

(Description of Embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 2 shows a circuit of a clothes dryer according to an embodiment of the present invention, where ■ is an AC power supply, 2 and 3 are semiconductor elements for controlling the power of the motor and heater, and 4 is a semiconductor element 2.
- A controller that controls 3; 5, a motor that rotationally drives the drum and the blower fan; 6, a phase advance capacitor for the motor 5; 7, a heater; and 8, a motor current detection circuit that detects the current flowing through the motor 5.

The operation of the clothes dryer configured as above will be explained. After the AC power source l is turned on, the semiconductor elements 2 and 3, which were initially turned off, are turned on by the controller 4.
Motor 5 and heater 7 operate. The motor current detection circuit 8 detects the current flowing through the motor 5 at any time, and determines the amount of load inside the drum based on motor current amplitude fluctuations. This determination method will be explained in more detail.

Figure 3 shows the amplitude fluctuations of the motor current under various loads, with (a) showing no load and (b
) shows the case when 10 cotton test cloths were used, and (C) shows the case when 20 cotton test cloths were used. This amplitude variation in the motor current is caused by a change in the load on the motor each time the material to be dried hits the buckle in the drum. FIG. 4 is a block diagram showing an example of a case where the aforementioned motor current detection circuit (8) detects a current portion of the current flowing through the motor that changes depending on the amount of load. The steps include filtering by the pantone filter 13, rectification 14, and integration 15, and the upper limit of the bandpass filter 13 is ((drum rotation speed) x (buckle taste)) [H2].

Based on the load detected as described above, the controller 4
is for controlling the semiconductor elements 2 and 3.

In the above embodiments, the determination was made based on the current value of the motor during steady state, but the inrush current value at startup may also be determined, or the voltage across the motor's phase advance capacitor may be used for determination. .

(Effects of the Invention) As explained above, in the present invention, the amount of material to be dried can be determined independently of the heater, so there is no need to worry about the temperature inside the drum rising abnormally and damaging the fabric when a small load is applied. ,
This provides the great advantage of being able to detect the amount of material to be dried at any time, even during the second continuous drying or during drying. Detecting the amount of drying material in a clothes dryer is not only a display of the remaining time, but also enables process control such as lowering the heater power to save energy when the load is small, variable drum rotation speed, and air volume control. It is indispensable, and its practical effects are indispensable.

[Brief explanation of the drawing]

Fig. 1 is a characteristic diagram showing the relationship between load amount and temperature rise to explain the conventional method of detecting the amount of dried material based on the temperature rise rate, and Fig. 2 is a clothes dryer according to an embodiment of the present invention. 3 is a waveform diagram showing amplitude fluctuations of motor current under various loads. FIG. 4 is a diagram showing the amplitude fluctuation of the motor current in an embodiment of the present invention, in which the load amount is determined from the amplitude fluctuation of the motor current. This is a useless block diagram. 1... AC power supply, 2.3... semiconductor element, 4...
Controller, 5...Motor, 7...Heater, 8.
...Motor current detection circuit. Figure 1 □ Clear skies Figure 2

Claims (2)

[Claims] (1) A drum that accommodates and stirs a load, a heater and a fan for sending hot air into the drum, a motor that rotationally drives the drum, and the heater, fan, and motor individually or collectively. a control circuit that controls the
and a load amount detection circuit that detects a load amount based on a change in the characteristics of both or one of the current and voltage applied to the motor, and the control circuit detects the heater, A clothes dryer characterized by controlling a fan or a motor. (2) The load detection circuit detects the steady component of the current/voltage applied to the drum and rotating motor or [(drum rotational speed)
× (number of baffles)) The clothes dryer according to claim 1, wherein the load amount is detected by a changing component of a frequency equal to or lower than H7.