JPS647340B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drying rate detection device for a dryer that detects the drying rate of a material to be dried using a detection electrode installed in a rotating drum.

Traditionally, in drum-type dryers, a pair of detection electrodes are installed inside the rotating drum serving as the drying chamber, and a pair of annular slip rings concentric with the rotation center of the rotating drum are attached to the outer surface of the rotating drum. is electrically connected to the pair of detection electrodes, and a pair of brushes are brought into sliding contact with the pair of slip rings, so that the detection electrodes are connected to the drying material from the pair of brushes as the rotating drum rotates. The electrical resistance value of the clothing detected by contacting the clothing is read out as drying rate data,
A device has been proposed that detects that the clothes have been dried to a predetermined drying rate based on this drying rate data and stops the drying operation. However, in the conventional configuration described above, the slip ring is relatively large and has a complicated structure, and since the brush is constantly in sliding contact with the slip ring, there is significant wear on both, making it difficult to accurately read drying rate data. It was difficult.

The present invention has been made in view of the above circumstances, and its object is to provide a detection electrode in a rotating drum, provide a floating charging capacitor in the rotating drum, and energize the floating charging capacitor to detect the detection electrode. A data detection and storage circuit for detecting and storing drying rate data of the object to be dried according to the detected electric resistance value of the electrode is provided, and the data detection and storage circuit is electrically connected to the floating charging capacitor and the data detection and storage circuit to the rotating drum. A plurality of contacts are provided, and the contacts are periodically contacted in accordance with the rotation of the rotating drum, and when the contacts are made, DC power is supplied to the floating charging capacitor, and the storage dryness rate of the data detection and storage circuit is controlled. By arranging a plurality of brushes for reading data at appropriate stationary parts, the contact can be made smaller and simpler in structure than conventional slip rings. It is an object of the present invention to provide a drying rate detection device for a dryer that can minimize wear between the brush and the brush and can read out drying rate data reliably.

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

First, the basic configuration will be described according to FIG. Reference numeral 1 designates a rotary drum serving as a drying chamber rotatably disposed in an outer box (not shown), and a front end plate 2 of the rotating drum 2 has an opening 3 for loading and unloading clothes to be dried at approximately the center thereof, and a peripheral side plate 4. Three buffles 5 are formed at regular intervals and extending in the axial direction to protrude inward. 6 is a mounting board attached to the inner surface of one buttful 5 of the rotating drum 1;
This extends in the axial direction of the rotary drum 1, and its front end passes through the front end plate 2, is curved, and is attached to the front end plate 2 to form an auxiliary base plate 7. Reference numerals 8 and 9 denote a pair of elongated detection electrodes, which are attached to the mounting substrate 6 so as to be parallel to each other with a predetermined distance therebetween. A plurality of contacts 10, 11, and 12, for example, three contacts, are attached to the outer surface of the auxiliary board 7.
Reference numeral 13 denotes a mounting member located on the front end plate 2 side of the rotating drum 1 and attached to an outer box that is a suitable stationary part. Brush 14, 15 and 16
The proximal end of is attached. In this case, the tips of the brushes 14, 15, and 16 come into contact with the contacts 10, 11, and 12 for a short predetermined period every time the rotating drum 1 makes one revolution in the direction of arrow A.

Now, the configuration of the electric circuit will be described according to FIG. 17 is a floating charging capacitor connected between the contacts 10 and 12, and a current-limiting resistor 18 and a constant voltage diode 1 with the polarity shown are connected between both terminals of the floating charging capacitor.
9 series circuits are connected, and the constant voltage diode 1
9 in parallel with a resistor 20 for voltage division, detection electrodes 8, 9,
A series circuit of a voltage dividing resistor 21 and a detecting resistor 22 is connected. In this case, the resistor 20, the detection electrodes 8, 9, and the resistors 21 and 22 constitute a detection circuit for detecting the electrical resistance value of the clothes to be dried in the rotary drum 1 as a voltage. 24 is an operational amplifier for configuring an instantaneous value detection circuit which is a data detection and storage circuit, and this is connected between both terminals of the floating charging capacitor 17, and its positive (+) input terminal is connected to the resistors 21 and 22.
The output terminal is connected to the negative (-) input terminal via a reverse current blocking diode 25 and a resistor 26 of the illustrated polarity. and,
The cathode of the diode 25 is connected to the contact 11
It is also connected to the contact 12 via a parallel circuit including a data storage capacitor 27 and a discharge resistor 28. In addition, the above-mentioned floating charging capacitor 17, resistor 18, constant voltage diode 19, resistors 20 to 22, operational amplifier 2
3. Of course, the diode 25, the resistor 26, the data storage capacitor 27, and the resistor 28 are provided on the rotating drum 1. On the other hand, the brush 1
4 is a power supply terminal 29 to which DC power supply voltage +V is applied.
, the brush 16 is grounded, and
The brush 15 is connected to an input terminal of a determination circuit 30. This determination circuit 30 detects the voltage between the terminals of the data storage capacitor 27, and when the voltage exceeds a predetermined level, it generates an operation command signal from the output terminal, and when it falls below the predetermined level, it generates a stop command signal. Its output terminal is connected to the input terminal of the drive circuit 31. This drive circuit 31 includes the determination circuit 30
An electric heater 33 serving as a heat source for supplying hot air into the rotating drum 1 when an operation command signal is given from the determination circuit 30 and a drive motor 34 for driving a blower fan (not shown) also constitute a control circuit 32. energizes and activates the judgment circuit 3.
When a stop command signal is given from 0, the electric heater 33 is first cut off, and then the drive motor 34 is cut off after a predetermined period of time. Incidentally, the drive motor 34 also rotates the rotary drum 1 in the direction of arrow A.

Next, the operation of this embodiment having the above configuration will be explained. When a power switch (not shown) is turned on, first, the determination circuit 30 generates an operation command signal, and based on this, the drive circuit 31 energizes the electric heater 33 and the drive motor 34, and hot air is supplied into the rotating drum 1. At the same time, the rotary drum 1 comes to be rotated in the direction of arrow A by the drive motor 34, and the drying operation is started. Then, when the rotating drum 1 is rotated in the direction of arrow A, the brushes 14, 15 and 16 are moved to the contactors 10, 1 in one rotation period.
1 and 12, but in this case,
First, when the brushes 14 and 16 come into contact with the contacts 10 and 12, the floating charging capacitor 17 is supplied with the DC power supply voltage +V and is floatingly charged, and the voltage between its terminals is applied to the constant voltage diode 19 via the resistor. A constant voltage is generated between both terminals of the constant voltage diode 19, and this constant voltage is applied to the series circuit of the resistor 20, the detection electrodes 8 and 9, and the resistors 21 and 22. Similarly, rotating drum 1 is moved to arrow A.
Each time the brushes 14 and 16 rotate in the
0 and 12, the floating charging capacitor 17 is charged, and the resistor 20, the detection electrodes 8 and 9, and the resistor 21
A constant voltage is always applied to the 22 series circuits. On the other hand, when the rotating drum 1 rotates,
The clothes to be dried inside are stirred by the Buzzful 5, and during the stirring, the clothes come into intermittently contact with the pair of detection electrodes 8, 9, and the pair of detection electrodes 8, 9 are Detects the electrical resistance value when it comes into contact with clothing. That is, the detection electrodes 8, 9
Each time clothing comes into contact with the resistor 20, the detection electrode 8,
A current flows through the detection resistor 22 through the resistor 9 and the resistor 21, and a detection voltage Va is generated between its terminals.
In this case, the electrical resistance value of the clothing is low when the drying rate at the final stage of drying is low, and increases as drying progresses, that is, as the drying rate increases,
Therefore, when the drying rate of clothes is small, the detection electrode 8,
A large detection voltage Va is generated each time clothing comes into contact with the detection electrodes 8 and 9, and conversely, when the drying rate of the clothing is high, a small detection voltage Va is generated each time clothing comes into contact with the detection electrodes 8 and 9.
will occur. Since such a detection voltage Va is applied to the positive input terminal of the operational amplifier 23, the operational amplifier 23 generates an output voltage corresponding to the detection voltage Va and sends it to the data storage capacitor via the diode 25. Therefore, the data storage capacitor 27 is charged to a voltage corresponding to the detection voltage Va, and an output voltage is output between its terminals as the drying rate data.
Generates Vb. Furthermore, the output voltage Vb from the data storage capacitor 27 is immediately applied to the discharge resistor 2.
8, but in this case,
The time constants of the data storage capacitor 27 and the resistor 28 are set to be relatively large, so that when the detection voltage Va is large, clothing comes into contact with the detection electrodes 8 and 9 before the output voltage Vb drops below a predetermined level due to discharge. A large detection voltage Va is generated based on which the data storage capacitor 27 is recharged. Similarly, the data storage capacitor 27 is repeatedly charged and discharged, and its output voltage Vb does not fall below a predetermined level when the detection voltage Va is large. This output voltage Vb is the brush 14,
Every time 15 and 16 come into contact with the contacts 10, 11 and 12, the signal is sent to the judgment circuit 30 via the contacts 11 and 12 and the brushes 15 and 16, and the judgment circuit 30 continues to send the operation command signal. It will start to occur. After that, when the drying rate of the clothes becomes almost complete and the drying rate increases, the detection voltage Va
becomes small, the charging voltage of the data storage capacitor 27 also becomes small, and the data storage capacitor 27
The output voltage Vb gradually decreases and approaches a predetermined level, and finally becomes less than the predetermined level. Therefore, when the output voltage Vb, which has become below this predetermined level, is read and input to the determination circuit 30 by the brushes 15 and 16 coming into contact with the contacts 11 and 12, the determination circuit 30 immediately generates a stop command signal. As a result, the drive circuit 31 connects the electric heater 33
Then, after a predetermined time, the drive motor 34 is cut off, and the drying operation is completed.

As described above, according to this embodiment, the brushes 14, 15, and 16 are moved to the contactor 1 every rotation of the rotary drum 1.
By contacting terminals 0, 11 and 12, the floating charging capacitor 17 is charged each time, and the output voltage Vb of the data storage capacitor 27 that stores the drying rate data of clothes is read out. The brushes 10, 11 and 12 can be made smaller and have a simpler structure than conventional slip rings, and the brushes 14, 1
5 and 16 contact the contacts 10, 11 and 12 every rotation of the rotating drum 1, that is, periodically,
Unlike conventional slip rings and brushes that are in constant contact, there is significantly less wear, and therefore the output voltage Vb, which is the drying rate data, is reduced due to poor contact due to wear.
There is no difficulty in reading the data, and the data can be read accurately.

In the above embodiment, the output voltage Vb is determined by the judgment circuit 3.
0 and immediately generates a stop command signal when this becomes below a predetermined level. A configuration may also be used in which a stop command signal is generated when it is detected that the voltage Vb is below a predetermined level multiple times.In this way, erroneous detection when the output voltage Vb temporarily becomes below a predetermined level can be avoided. It can be prevented.

In addition, the present invention is not limited only to the embodiments described above and shown in the drawings, and it goes without saying that the present invention can be implemented with appropriate modifications within the scope of the invention.

As is clear from the embodiments described above, the present invention allows a plurality of contacts for supplying DC power and reading drying rate data to be made smaller and simpler in structure than conventional slip rings. In addition, wear between the contactor and the brush can be minimized, and
It is possible to provide a drying rate detection device for a dryer that has excellent effects such as being able to reliably read drying rate data.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the basic configuration of an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the configuration of an electric circuit of the same embodiment. In the drawing, 1 is a rotating drum (drying room), 8 and 9
are detection electrodes, 10 to 12 are contacts, 14 to 1
6 is a brush, 17 is a floating charging capacitor, 24 is an instantaneous value detection circuit (data detection storage circuit), 27 is a data storage capacitor, 32 is a control circuit, 33
is an electric heater (heat source), 34 is a drive motor, Va is a detection voltage, and Vb is an output voltage (drying rate data).

Claims (1)

[Claims] 1. A rotating drum serving as a drying chamber, a detection electrode provided in the rotating drum to contact the material to be dried and detect its electrical resistance value, a floating charging capacitor provided in the rotating drum, and a data detection storage circuit that is provided on the rotating drum so as to be energized by a floating charging capacitor and detects and stores drying rate data of the object to be dried according to a detected electric resistance value of the detection electrode; A plurality of contacts are provided on the rotating drum to be electrically connected to the floating charging capacitor and the data detection and storage circuit, and a plurality of contacts are provided at appropriate stationary parts and are connected to the contactors in accordance with the rotation of the rotating drum. Drying of a drying machine comprising a plurality of brushes that periodically come into contact with each other and supply direct current power to the floating charging capacitor at the time of contact and read out drying rate data stored in the data detection and storage circuit. rate detection device.