JPS60225600A - 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 (Technical Field of the Invention) The present invention relates to a clothes dryer configured to dry clothes in a rotating drum, and particularly to a clothes dryer in which the drying rate of clothes in the rotating drum is controlled by contacting the clothes. The present invention relates to a clothes dryer in which drying is detected using a pair of electrodes provided in this manner, and the drying operation is stopped when a certain period of time has elapsed after the detected drying rate reaches a set value.

[Technical background of the invention and its problems]

Conventionally, in clothes dryers, a pair of electrodes that come in contact with the clothes inside the rotating drum are installed, and the drying rate of the clothes is detected based on the resistance value between the electrodes when the clothes come into contact between the electrodes. At the same time, a delay timer is provided that executes a timer operation for a certain period of time when the detected drying rate reaches a set drying rate, and the drying operation is stopped when the timer operation of this delay timer ends. ing. With such a configuration, the drying rate of the clothes in the rotating drum can be detected by the electrodes that are in direct contact with the clothes, which has the advantage of increasing the detection accuracy. The condition is determined before the clothes are completely dried (in this state, the degree of change in the drying rate of the clothes is relatively large), taking into consideration the duration of the drying operation. There is also the advantage that the above judgment error is reduced, and as a whole, the timing of stopping the drying operation can be accurately controlled. However, with such a configuration, when the amount of clothing in the rotating drum is small or when the so-called cloth circulation in the rotating drum is poor,
The detected drying rate tends to be higher than the actual drying rate due to the decrease in the contact pressure and frequency of contact between the clothes and the electrodes, which causes the problem that the drying operation is stopped before the clothes are sufficiently dried. This often happened.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to improve the detection accuracy by detecting the drying rate of clothing in a rotating drum using a pair of electrodes that are in direct contact with the clothing. Although the configuration is
To provide a clothes dryer that can reliably prevent the occurrence of a situation where a drying operation is stopped while the clothes are insufficiently dried due to a decrease in the contact pressure and contact frequency of the clothes.

[Summary of the invention]

The present invention provides a detection circuit that detects the drying rate of clothing in a rotating drum using a pair of electrodes provided in contact with the clothing, and also provides a detection circuit that detects the drying rate of clothing in a rotating drum by detecting a certain period of time after the detected drying rate reaches a set value. In a clothes dryer that is provided with a delay timer that sometimes stops the drying operation, there is provided a humidity sensor that detects the humidity of the exhaust air from the rotating drum, and a humidity sensor that detects the humidity after the timer operation of the delay timer starts. A backup circuit is provided in each case to perform an extra drying operation for an amount of time corresponding to the detected humidity when the humidity exceeds a certain value at a predetermined time. This is to compensate for the lack of drying operation time.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

1 is a step-down transformer that receives the output of the AC power supply 2; 3 is a DC power supply circuit that rectifies and smoothes the secondary output of the step-down transformer 1; its output terminals A1. DC constant voltages of different levels are output from each of A2 and A3. 4 is a detection circuit that is supplied with power from the DC power supply circuit 3, which will be described below. That is, 5.6 is a pair of electrodes arranged in a rotating drum (not shown) so that the clothes being agitated in the rotating drum can come into contact with each other. The other electrode 6 is connected to the output terminal A1 through a resistor 8.9. In this case, the resistance value between the electrodes 5 and 6 decreases to a level corresponding to the drying rate of the clothing each time the clothing comes into contact with the electrodes 5 and 6. It increases as the rate increases. Therefore, as a result,
A detection voltage Vd is output from the common connection point a between the resistors 8 and 9, which changes in inverse proportion to the drying rate of the clothes each time the clothes come into contact between the electrodes 5 and 6. 10 is the detection voltage Vd because the detection voltage Vd is output only intermittently.
A capacitor is provided to allow a certain period of time to pass, and the voltage V' d between the terminals of the capacitor is transferred to the buffer amplifier IL, 12. It is applied to the inverting input terminal (-) of the comparator 14 via the diode 13. Further, 15 is a reference voltage generation circuit consisting of a resistor 16.17 connected in series between the output terminals At and A2, and generates a reference voltage VS corresponding to the set drying rate from the common connection point between the resistors 16.17. and comparator 14
Apply to the non-inverting input terminal (+) of

Therefore, the comparator 14 outputs a high level signal when the relationship v' d <vs, in other words, when the drying rate detected by the electrode 5.6 reaches the set drying rate. When the signal is output, the transistor 18 turns on, and in response to this turning on, the output terminal Ar
, A3, the excitation coil 19a of the relay 19 is energized. In the detection circuit 4, Cl2O is a correction circuit that determines the amount of clothing in the rotating drum based on the average value of the detection voltage Vd, and also connects the inverting input terminal (-) of the comparator 14 based on the determination result. )
The inter-terminal voltage V'd given to the terminal is corrected.

On the other hand, 21 is a timer motor 22 and a cam switch 23.
24, which turns on the cam switch 23 in response to a set operation by an operator (not shown), and turns on the cam switch 24 immediately after the start of timer operation in response to energization of the timer motor 22. Later, when a predetermined period of time has elapsed, the cam switch 23.2
4 is turned off. Then, the timer motor 2
2 is a normally closed contact 19b of the relay 19, a normally closed contact 25b of a relay 25, which will be described later, and the cam switch 2.
3 in series between both terminals of the AC power supply 2. Also, in response to turning on the cam switch 23, the AC power supply 2
From this, electricity is supplied to the rotating drum, the motor 26 for driving a blower fan (not shown), the heater 27.2B for drying operation, and the step-down transformer 1.

Reference numeral 29 is, for example, an electrical resistance type humidity sensor provided to detect the humidity of the exhaust gas from the rotating drum, and this sensor has a property that the resistance value decreases as the detected humidity increases. 30 is a backup circuit including the relay 25, which will be described below. That is, 32 is a voltage dividing circuit, which connects a series circuit of resistors 33 and 34 between both terminals of the AC power supply 2 and the cam switch 23.2.
It is connected via 4. 33 is an inverting amplifier with the humidity sensor 29 as an input resistance, which converts the output voltage of the voltage dividing circuit 32 (the voltage between the terminals of the resistor 34) to a predetermined amplification factor (the resistance value of the humidity sensor 29 is R5°, and the feedback resistor 33a The resistance value of the signal is inverted and amplified by R (Rf/Rs). and,
The relay 25 has an inverting amplifier 33 in its excitation coil 25a.
The resistor 34 and the diode 35 are electrically connected to each other through a resistor 34 and a diode 35.

Next, the operation of the above configuration will be explained. When clothes are put into the rotating drum and the delay timer 21 is set, the cam switch 23 is turned on, so the detection circuit 4. The motor 26 and heaters 27 and 28 are now energized. Then, the motor 26 rotates the rotating drum and the feeding fan, and the clothes in the rotating drum are agitated, and air heated by the heaters 27 and 28 is supplied into the rotating drum by the blowing fan, which is a hot air drying operation. will be carried out. During such a drying operation, the clothes come into contact intermittently between the electrodes 5 and 6, and each time there is contact, a detection voltage Vd that changes in inverse proportion to the drying rate of the clothes is output from the connection point a. At the same time, this detected voltage Vd is stored as the inter-terminal voltage V'd of the capacitor 10 for a certain period of time. Thereafter, as the drying operation progresses, the detection voltage Vd and the voltage V' between the terminals of the capacitor 10
When d decreases and the relationship Vd'<Vs, a high level signal is output from the comparator 14 and the transistor 1
8 is turned on. Then, the excitation coil 19 of one relay
A is energized and its normally closed contact 19b is turned on, so
The timer motor 22 of the delay timer 21 is connected to the cam switch 23
．． Normally closed contact 25b of relay 25 and the above normally closed contact 19b
The delay timer 21 is now energized through the delay timer 21.
Immediately after the timer operation is started, the backup circuit 30 is energized so that the delay timer 21 turns on the cam switch 24.

At this point, if the humidity detected by the humidity sensor 29 is less than a certain value, the humidity sensor 29 exhibits high resistance and the amplification factor of the inverting amplifier 33 becomes small, resulting in the relay 25 being in a non-driving state. normally closed contact 2
5b is kept in the on state, thereby continuing to energize the timer motor 22. Therefore, in this case, the timer operation of the delay timer 21 is executed without interruption. Further, as described above, if the humidity detected by the humidity sensor 29 is equal to or higher than the predetermined value at the time the cam switch 24 is turned on, the humidity sensor 29 exhibits a low resistance and the amplification factor of the inverting amplifier 33 increases. Therefore, the relay 25 is driven by the output of the inverting amplifier 33 and its normally closed contact 25b is turned off, so that the timer motor 22 is de-energized and the timer operation of the delay timer 21 is interrupted. Then, as the drying operation progresses thereafter, when the drying rate of the clothes reaches an upper limit and the humidity detected by the humidity sensor 29 becomes less than a certain value, the relay 25 is held in the non-driven state as described above, and the normally closed contact 25b Since the timer motor 22 returns to the on state, the timer motor 22 is energized again and the timer operation of the delay timer 21 is restarted. When the timer operation of the delay timer 21 is finally completed, the cam switches 23 and 24 are turned off, so that the detection circuit 4. Motor 26. The energizing paths to the heaters 27, 28 and the backup circuit 30 are cut off, and the drying operation is ended.

By the way, if the amount of clothing in the rotating drum is small or if the so-called cloth movement in the rotating drum is poor, the electrode 5.
Since the contact pressure and frequency of contact between the clothes and the electrodes 5 and 6 decrease, the drying rate detected by the electrodes 5 and 6 tends to be higher than the actual drying rate. If the timer operation of the delay timer 21 is started and the human drying operation is stopped in response to the end of the timer operation, there is a problem that the drying operation time becomes insufficient and the clothes are insufficiently dried. However, in this embodiment, the timer operation of the delay timer 21 is interrupted only for a period from immediately after the relationship v'd<vS is established until the exhaust humidity in the rotating drum falls below a certain value. Since the drying operation is extended by a time corresponding to this period, the above-mentioned problem can be solved.

Of course, in this embodiment, the drying rate of the clothes in the rotating drum is detected by the electrodes 5 and 6 that are in direct contact with the clothes, so if the amount of clothes in the rotating drum is more than an appropriate amount and the drying rate of the clothes in the rotating drum is When the fabric inside the dryer has a normal circumference, the detection accuracy by the electrodes 5 and 6 becomes sufficiently high, and the timing of stopping the drying operation can be accurately controlled.

In the above embodiment, if the humidity detected by the humidity sensor 29 is equal to or higher than a certain value immediately after the timer operation of the delay timer 21 starts, the timer operation of the delay timer 21 is performed only until the detected humidity becomes less than the certain value. Although the configuration is such that the interruption is not necessarily limited to this configuration, for example, when the detected humidity at the end of the timer operation of the delay timer is above a certain value, the interruption is performed only until the detected humidity becomes less than the certain value. It is also possible to have a configuration in which the drying operation is forced to continue, and the point is that if the humidity detected by the humidity sensor exceeds a certain value at a predetermined time after the delay timer starts operating, the drying operation continues only for a period of time corresponding to the detected humidity. A configuration may be adopted in which an extra drying operation is performed.

〔Effect of the invention〕

According to the present invention, as is clear from the following explanation,
The drying rate of the clothes in the rotating drum is determined by touching the clothes directly.
Although the clothes dryer is configured to increase the detection accuracy by detecting with a pair of electrodes, the clothes are insufficiently dried due to a decrease in the contact pressure and frequency of contact between the clothes and the electrodes. This provides an excellent effect in that it is possible to reliably prevent the drying operation from being stopped while the drying operation is still in progress.

[Brief explanation of drawings]

The drawing is a wiring diagram showing one embodiment of the present invention. In the figure, 4 is a detection circuit, 5 and 6 are electrodes, 21 is a delay timer, 29 is a humidity sensor, and 30 is a backup circuit. Applicant Toshiba Corporation Procedure 7 City 1'[TA"J Director General of the Patent Office 1, Indication of the case Patent application 1984-84668 2, Title of the invention Clothes dryer 3, Amendment with the case Related: Patent applicant Trando (307) Toshiba Corporation 4, Agent 5, Old case of amendment order Voluntary

Claims (1)

[Claims] 1. A detection circuit that has a pair of electrodes in contact with the clothes in a rotating drum and detects the drying rate of the clothes based on the resistance value between the electrodes, and the drying rate detected by this detection circuit reaches a set value. and a delay timer that is activated to start a timer operation when the timer operation is completed and to stop the drying operation when the timer operation ends, a humidity sensor that detects the humidity of exhaust air from the rotating drum; □A backup circuit is provided to perform drying operation for an extra time corresponding to the detected humidity when the detected humidity by the humidity sensor exceeds a certain value at a predetermined time after the timer operation of the delay timer starts. Characteristic clothes dryer.