JPS5914889A - Drying detecting apparatus of 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] The present invention relates to a drying control device for a dryer.

Conventionally, when operating a dryer, the common method was to adjust the drying time by setting a timer to an appropriate time. However, this method has the disadvantage that if the timer is set incorrectly, the drying process may result in incomplete drying or over-drying, which may damage the material to be dried. Ta.

In addition, various control methods have been considered to overcome this drawback, but these also have major problems.

For example, in the case of a clothes dryer, there are some that try to detect changes in the humidity of clothes by changes in the average resistance of the clothes in contact with the electrodes, but in this method, the electrodes are exposed inside the clothes storage compartment. , which required extreme measures in terms of electrical safety. Furthermore, since a high resistance is measured, preventing leakage current from the control device itself becomes an extremely difficult problem.

Another method is to control drying by detecting the relative difference between the exhaust temperature of the dryer and the ambient temperature, but with this method, if the amount of cloth is small, most of the hot air is exhausted as is. This had the disadvantage that the cloth would be cut prematurely even though it was not sufficiently dry.

The present invention reliably and accurately detects the end of drying in order to compensate for the drawbacks of the conventional methods.

FIG. 1 shows the basic configuration of the present invention, where 1 is for storage,
The material to be dried is physically agitated, such as in a rotating drum system. As the material to be dried becomes dry, static electricity is generated on the surface of the material due to friction during stirring. This static electricity is detected by the static electricity detection sensor 1, and upon receiving this signal, the control means 2 performs appropriate operation control to cause the drying means 3 to complete the drying operation.

Next, an example in which the present invention is applied to a clothes dryer will be described.

FIG. 2 shows a schematic structure of this embodiment. Reference numeral 5 denotes a door provided for taking clothes in and out, and reference numeral 6 denotes a rotating drum for physically agitating the clothes, which has a central axis of rotation in a substantially horizontal direction. Reference numeral 7 denotes a fixed wall, which constitutes a surface in a direction substantially perpendicular to the rotation center axis. The door 52, rotating drum 6, and fixed wall 7 constitute a storage warehouse shown at 4 in FIG.

The static electricity detection sensor 1 is installed on the fixed wall 7.
' Fixed by ox8. The rotating drum 6 is rotatably attached within the exterior casing 10 by a support portion 9. A motor 11 rotates the rotary drum 6 via a belt 12 and the fan 14 via a belt 13, respectively. 15 is an intake port, 16 is a heater, 17 is an intake window of the housing 4, 18 is an exhaust window of the housing 4, and 19 is an exhaust port.

The above-mentioned 77-in 14 works to discharge the air inside the storage compartment 4 to the outside of the aircraft, and the outside air flows into the aircraft through the intake port 15, is heated by the heater 16, and then passes through the intake window 1 of the storage compartment 4 into the storage compartment. 4 and heats the clothes in the storage compartment 4. As a result, air and water vapor generated from the clothes are discharged to the outside of the storage compartment 4 through the exhaust window 18 of the storage compartment 4, and further to the outside of the machine through the exhaust port 19.

FIG. 3 shows a schematic configuration of the static electricity detection sensor 1, where 2o is a conductive plate and 21 is a resin layer provided to electrically insulate the conductive plate 20 from clothing. With this configuration alone, when drying synthetic fibers, etc., the resin layer 21 itself becomes charged due to friction from the cloth even though the drying is insufficient, and accurate static electricity detection cannot be performed. A conductive layer 22 is provided on the surface of the layer 21 by coating or the like. The conductive plate 20 is connected to the control means 2 by an electric wire.

When the clothes are dry, the clothes are subjected to friction due to the movement of the rotating drum 6 and become electrically charged. At this time, the clothing has a mixture of positively charged parts and negatively charged parts. When focusing on a certain part of the clothing, that part moves within the storage 4 almost following the movement of the rotating drum 6. Therefore, the movement of the charges passing near the static electricity detection sensor 1 repeats almost following the movement of the rotating drum 6, and the potential at the position of the static electricity detection sensor 1 also changes in accordance with the same repetition. The static electricity detection sensor 1 has the role of transmitting a change in potential due to the movement of charges to the control means 2 by an electrostatic induction phenomenon occurring on the conductive plate 2o.

-・, *4 [1t"UL (*%El"Hifl in U7
k-+L, 23 IriN source plug, 24 a power switch. 25, 267·'>' are capacitors used to prevent noise leakage of the motor 11 and to keep the potential of the control means 3 constant with respect to the ground, and to provide a reference for the potential of the static electricity detection sensor 1. 2
7.28 is a switching element, 29 is a drying operation control unit,
31 and 32 are time delay sections.

32 is a transformer that steps down the voltage of the commercial power supply.

Reference numeral 33 denotes a full-wave rectifier for rectifying this alternating current power. Electrolytic capacitors 34 and 35 smooth it into direct current, and Zener diodes 36 and 37 are provided to stabilize the voltage of this direct current. These transformer 32, full wave rectifier 33, electrolytic capacitors 34, 35, Zener diodes 36, 37
constitutes a power supply circuit of the control means 2, and the cathode of the Zener diode 360 and the anode of the Zener diode 3γ generate DC voltages having equal positive and negative absolute values, respectively, with respect to the ground.

1° is a static electricity detection unit which inputs the signal from the static electricity detection sensor 1 and sends an output to time delay units 30 and 31. The time delay sections 30.31 receive the output signal from the static electricity detection section 11 and transmit the output signals to the switching elements 27.28, respectively. It is assumed that the switching elements 27 and 28 are non-conductive when receiving the output signal of the time delay section 30 and 31, and are conductive otherwise. These switching elements 27 and 28 constitute a drying operation control section 29. Further, the control means 2 includes a static electricity detection section 1°, time delay sections 30 and 31, and a drying operation control section 29.

The configuration and operation of the static electricity detection section 1' will be explained below.

The static electricity detection sensor 1 is a Zener diode 38°39,
It is connected to the positive input terminal of an operational amplifier 44 along with a resistor 40 and a capacitor 41 . Zener diode 38.
39 is for protection of the operational amplifier 44. Since static electricity has small energy, in order to detect it, the resistor 40 must have a high impedance of several MΩ and the capacitor 41 must have a high impedance of several thousand pF. resistance 4
2 is connected between the negative input terminal of the operational amplifier 44 and the ground, and a resistor 9 is connected between the negative input terminal and the output terminal of the operational amplifier 44. These resistors 42 and 43 and the operational amplifier 44 constitute a common mode voltage amplification circuit. While amplifying the potential fluctuation signal detected by the static electricity detection sensor 1,
The impedance of the signal source is low.

The output terminal of the operational amplifier 44 is connected to the negative input terminal of the operational amplifier 48 via resistors 45 and 46, and the connection point between the resistors 45 and 46 is connected to ground via a capacitor 47.

The resistors 49, 50 and the capacitor 51 connected in series are both connected between the negative input terminal and the output terminal of the operational amplifier 48, and the connection point between the resistor 49 and the resistor 5o is connected to the ground via the capacitor 52, and the operational amplifier The positive input terminal 48 is connected to ground. The input circuit of the operational amplifier 48 consisting of a resistor 45, 46 and a capacitor 47, and the feedback circuit of the operational amplifier 48 consisting of a resistor 49, 50 and a capacitor 51, 52 each have unique frequency characteristics. , resistance 10be, -2
- Anti-45, 46, 49, 50. Capacitor 47, 51.5
2 constitutes a low-pass filter. The cutoff frequency and gain of this low-pass filter are determined by the sizes of these resistors and capacitors.

As mentioned above, the fundamental frequency of the potential fluctuation signal detected by the static electricity detection sensor 1 is the number of rotations per second of the rotating drum, so this frequency is used as the cutoff frequency to eliminate harmful noise such as power supply hum. It is being removed. The potential fluctuation signal that has passed through the low-pass filter is passed through the diode 5.
3 is rectified by the comparator 5 through a smoothing circuit composed of a resistor 54.6i6 and an electrolytic capacitor 55
It is input to the non-inverting input terminal of 9. These diodes 5
3. The average voltage of the magnitude of the potential fluctuation signal due to static electricity is input to the non-inverting input terminal of the comparator 69 by the rectifying and smoothing circuit constituted by the resistors 54 and 56 and the electrolytic capacitor 55. Resistors 57 and 58 input the base voltage to the converter 2590 inverting input terminal. The unconstrained voltage of the magnitude of potential fluctuation due to static electricity is
When the voltage exceeds P, the output of the comparator 59 rises.

The above is a description of the configuration and operation of the static electricity detection section 11.

Now, when damp clothes are placed in the storage compartment 4 and the power switch 24 is closed, the switching elements 27 and 28 are normally in the conductive state as described above, so the motor 11 and the heater 16
is activated, and the clothes are stirred in the storage container 4 while being heated. When clothes reach a dry state, they begin to become electrically charged due to friction. When the clothing begins to be charged, the potential of the static electricity detection sensor 1 changes, and as described above, the voltage at point A in FIG. 4 increases. When the voltage at point A becomes equal to or higher than the reference voltage set by resistors 57 and 58, the output of comparator 59 rises and the signal is input to the input terminal of time delay section 30.31. The time delay unit 31 transmits an output signal to the switching element 28 when a predetermined time has elapsed from that point. When the switching element 28 receives this output signal, it immediately becomes non-conductive and stops supplying electricity to the heater 16. After a further predetermined period of time has elapsed, the time delay unit 30 transmits an output signal to the switching element 2. When the switching element 27 receives this output signal, it immediately becomes non-conductive, and the energization of the motor 11 is also stopped, completely completing the drying operation.

The correlation between the amount of static electricity generated and the drying rate differs slightly depending on the type of cloth, but the time required from the time static electricity begins to be generated to complete drying is generally from several minutes to more than ten minutes for any type of cloth. By setting the base voltage set by the resistors 57, 58 and the delay in the time delay section 30, 31 to appropriate values, an optimal drying end operation can be performed for any type of cloth or any layout.

Figure 5 shows a typical example, where the horizontal axis represents time and the vertical axis represents the voltage at point A in Figure 4.
Characteristic C is the case when the synthetic fiber is 0.5 to 51 for drying clothes, Characteristic C is the case when the cotton is 0.5 kg, and Characteristic C is the case when the cotton is I
The case of Kg is shown respectively. And each characteristic a, b, c
d indicates the complete dry point in the middle, and e indicates the reference potential set by the resistors 25 and 26. For each characteristic, the time t1. from e to d for 13 pages. t2. t3 is t1 soft t2; t3.

As shown in Figure 5, the clothes to be dried are synthetic fibers of 0.5 to 9, cotton of 0.5 to 9, cotton 1. In any of OR3, A
The time (tl, t2.t3) required for complete drying (drying rate reaches 101% for synthetic fibers and 103% for cotton) after the voltage at the point reaches a certain reference voltage is almost equal.

This means that static electricity will not build up on the clothes until they are almost dry, and setting a delay time from this point on will allow the clothes to dry very close to the necessary and fully dry condition. It shows that it can be terminated.

In addition, even if there is a very small amount of placement, or even if the fabric is treated with any kind of antistatic treatment, static electricity will definitely be generated, so depending on the configuration of this example, very reliable dryness detection can be achieved. I can do it.

As described above, according to the present invention, compared to the conventional method of detecting and controlling changes in the humidity of clothes or the method of detecting and controlling the relative difference between the exhaust air temperature from a dryer and the ambient temperature, It is possible to accurately and reliably detect the completion of drying of a dried material by electrostatic detection, a relatively simple means, and its industrial value is extremely large.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 is a schematic configuration of an embodiment of the present invention, FIG. 1A is a front view, FIG. The figure shows a static electricity detection sensor, and (A) is a side view. 4B is a cross-sectional view taken along line x-x' of FIG. 4, FIG. 4 is a specific electric circuit diagram, and FIG. 5 is a characteristic diagram showing the output state at point A in FIG. 1... Static electricity detection sensor, 2... Control means, 3... Drying means, 4... Container, 5... Door, 6...Rotating drum, 7.
... Fixed wall, 11 ... Motor, 14 ...
...Fan, 2o... Conductive plate, 21...
... Resin layer, 22... Conductive layer, 11...
・Static electricity detection unit, 29...Drying operation control unit, 3
0.31...Delay part to time.

Claims (3)

[Claims] (1) A storage for storing objects to be dried, a drying means for drying the objects to be dried, and a control means for controlling the operation of the drying means, and a static electricity detection sensor is provided in the storage; A drying control device for a dryer configured to input a signal from a static electricity detection sensor to the control means to terminate the operation of the drying means. (2) The storage is composed of a cylindrical rotating drum having a rotational center axis in a substantially horizontal direction, at least one fixed wall arranged perpendicularly to the rotational center axis, and a door, and the static electricity detection sensor The drying means is fixed to a part of the fixed wall, and includes a heater, a fan that blows air heated by the heater into the rotating drum, and a motor that drives the rotating drum, and the control means includes a static electricity detection device. part and two independent 2 parts that operate in response to signals from this static electricity detection part.
a page time delay section; and drying operation control that receives an output from one of these two time delay sections to stop energizing the heater, and receives the other output and stops energizing the motor. A drying control device for a dryer according to claim 1, comprising: a drying control device for a dryer; (3) A static electricity detection sensor consists of a conductive plate with an appropriate area, a resin layer formed on the conductive plate to electrically insulate the conductive plate, and a resin layer that prevents the resin layer itself from being charged. and a conductive layer provided on a resin layer, and detects changes in the potential of the conductive plate by electrostatic induction caused by charges generated in the object to be dried. Control device.