JPS648298B2 - - 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 in a rotating drum using a detection electrode.

Conventional devices of this kind have a pair of detection electrodes disposed inside a rotating drum, detect the electrical resistance value of clothing, which is the object to be dried, that comes into contact with the detection electrodes as drying rate data, and determine when the clothing has finished drying. The drying operation is configured to be stopped when the detected electrical resistance value reaches a predetermined high resistance value. However, with this configuration, if the clothing has conductive members such as metal buttons or fasteners attached, even if the clothing has finished drying and its electrical resistance reaches a predetermined high resistance value, When the conductive member comes into contact with the detection electrode, its detected electrical resistance value becomes a low resistance value, resulting in a false detection that the clothes are not yet dry, and there is a problem in that the drying operation is not stopped.

The present invention has been made in view of the above circumstances, and its purpose is to provide a detection unit that extracts the detected electrical resistance value of the detection electrode as a drying rate data signal and sequentially detects the peak values, A first storage means for sequentially updating and storing values is provided;
A second storage means is provided for sequentially updating and storing the memory value of the storage means, and detects an abnormal electrical resistance value when the detection electrode comes into contact with a conductive member such as a metal, generates a stop signal for a predetermined period of time, and stops the signal. By providing a conductor detection section that supplies information to the second storage means to stop its update storage operation, the drying rate data of the drying object can be reliably detected without being affected by the conductive member. To provide a drying rate detection device for a machine.

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

Reference numerals 1 and 1 denote a pair of detection electrodes, which are disposed within a rotating drum 2 serving as a drying chamber. 3 is a detection section, which will be described below. 4, 4 are brushes that come into sliding contact with the detection electrodes 1, 1, one of which is connected to a power supply terminal 6 to which DC power supply voltage + _Vcc is applied via a resistor 5, and the other is connected to a resistor 7 and a detection resistor. It is grounded via the device 8. The detection terminal 9, which is the common connection point of the resistor 7 and the detection resistor 8, is the input terminal Ia of the peak value detection circuit 10.
It is connected to the. This peak value detection circuit 10
When a low level L signal is applied to the control terminal Ib, the peak value of the signal applied to the input terminal Ia is sequentially stored, and when a high level H signal is applied to the control terminal Ib, the stored contents are reset. It's becoming like that. Reference numeral 11 denotes a monostable multivibrator circuit serving as a control circuit, and its output terminal is connected to the control terminal Ib of the peak value detection circuit 10.
On the other hand, 12 is a storage section, which will be described below. A storage circuit 13 is a first storage means, and its input terminal Ia is connected to the output terminal O of the peak value detection circuit 10. This memory circuit 13
is adapted to write and store the contents of the signal applied to the input terminal Ia every time a high level signal is applied to the control terminal Ib. Reference numeral 14 designates a monostable multivibrator circuit as a control circuit, the output terminal of which is connected to the control terminal Ib of the storage circuit 13 and the input terminal of the monostable multivibrator circuit 11. A storage circuit 15 is a second storage means, and its input terminal Ia is connected to the output terminal O of the storage circuit 13. This memory circuit 15
is adapted to sequentially write and store the contents of the signal applied to the input terminal Ia when a high level signal is applied to the control terminal Ib. Reference numeral 16 denotes a control pulse generation circuit consisting of an oscillation circuit, the output terminal of which is connected to the input terminal of the monostable multivibrator circuit 11 and one input terminal of the AND circuit 17. The output terminal of the AND circuit 17 is connected to the control terminal Ib of the memory circuit 15.
18 is a delay circuit whose output terminal is connected to the other input terminal of the AND circuit 17.
This delay circuit 18 is designed to output a low level signal from the output terminal when a high level signal is applied to the input terminal, and when the signal applied to the input terminal changes from high level to low level, the output terminal outputs a low level signal. A low level signal is output for a predetermined period of time, and then a high level signal is output. The input terminal of the delay circuit 18 is connected to the output terminal of the conductor detection section 19, and the input terminal of the conductor detection section 19 is connected to the detection terminal 9. This conductor detection section 19 outputs a low level signal from the output terminal when the content of the signal applied to the input terminal is lower than the abnormal setting value Vs, and outputs a high level signal when the content is equal to or higher than the abnormal setting value Vs. It's summery. Now, 20 is a determination circuit, the input terminal of which is connected to the output terminal O of the memory circuit 15. This judgment circuit 20
generates an operation command signal from the output terminal when the signal applied to the input terminal exceeds a predetermined value Va, and generates a stop command signal from the output terminal when the signal applied to the input terminal continues to be below the predetermined value for a certain period of time or more. is starting to occur. 21 is a drive circuit whose input terminal is connected to the output terminal of the determination circuit 20, and whose output terminal is connected to an electric heater 22 as a heat source and a drive motor 23 of a blower that generates hot air and supplies it into the rotating drum. It is connected. This drive circuit 21 energizes the electric heater 22 and the drive motor 23 when an operation command signal is given, and when a stop command signal is given, first the electric heater 22 is turned off and then the drive motor 23 is turned off after a certain period of time. It's getting old. Furthermore, the drive motor 23
The rotary drum (not shown) is also driven to rotate.

Next, the operation of this embodiment having the above configuration will be explained. When you close the power switch (not shown),
First, the determination circuit 20 begins to generate an operation command signal from its output terminal, and the drive circuit 21 begins to energize the electric heater 22 and drive motor 23.
As a result, hot air is supplied into the rotating drum, and the rotating drum is rotationally driven by the drive motor 23, and the clothes to be dried in the rotating drum are agitated, thus starting the drying operation. is started. Furthermore, when the clothing inside is agitated by the rotation of the rotating drum, the clothing comes into contact with the pair of detection electrodes 1, 1 intermittently, and each time the detection electrodes 1, 1 contact the clothing, the clothing is agitated. The electrical resistance value of the clothing is detected. Therefore, a current corresponding to the detected electric resistance value of the detection electrodes 1, 1 flows through the detection resistor 8, and a detection voltage _V9 is generated at the detection terminal 9. In this case, when the clothes are not dried, that is, when the drying rate is low, the detected electrical resistance value of the detection electrodes 1, 1 is small and the detection voltage _V9 is large, and as the clothes dry, that is, when the drying rate is low, As becomes larger, the detection electric resistance value of the detection electrodes 1, 1 becomes larger and the detection voltage V ₉ becomes smaller. Therefore, the detection voltage V ₉
is extracted as a signal indicating the drying rate data of the clothes, as shown in FIG. 2a. On the other hand, the control pulse generation circuit 16 generates a high-level pulse _P16 with a pulse width Ta over time
Since this pulse P ₁₆ is given to the monostable multivibrator circuit 14, the monostable multivibrator circuit 14 receives the rise of the pulse P ₁₆ as shown in FIG. It is triggered in the downward direction to generate a high-level pulse P ₁₄ with a pulse width Ta, and this pulse P ₁₄ is also given to the monostable multivibrator circuit 11, so that the monostable multivibrator circuit 11 It is triggered by the falling edge of pulse P ₁₄ to generate high-level pulse P ₁₁ with pulse width Ta. Therefore, the pulse P ₁₁ of the monostable multivibrator circuit 11 is detected by the peak value detection circuit 1.
Since the signal is applied to the control terminal Ib of 0, the peak value detection circuit 10 resets the peak value stored up to that point. That is, the peak value detection circuit 10 detects and stores the peak value of _the detection voltage _V9 shown in FIG. The storage peak value and storage period of the detection circuit 10 are shown by broken lines in FIG. 2a. Furthermore, when the pulse P ₁₄ is applied to the control terminal Ib of the storage circuit 13, the memory peak value of the peak value detection circuit 10 applied to its input terminal Ia is written and stored. ₁₁ is pulse width than pulse P ₁₄
Since the peak value M13 is generated with a delay of Ta, the storage circuit 13 stores the peak value _M13 of the peak value detection circuit 10 immediately before being reset by the pulse _P11 , as shown in FIG. 2e. Become. Furthermore, the conductor detection unit 19 has a detection voltage V ₉ of the second
A high level output signal is generated when the abnormality setting value Vs shown in figure a is exceeded.
Therefore, under normal conditions, a low level output signal is generated. As a result, the delay circuit 18 generates a high-level output signal _S18 as a permission signal and supplies it to the AND circuit 17, as shown in FIG. As shown in g, a high-level pulse P ₁₇ synchronized with pulse P ₁₆ is generated, and this is sent to the control terminal of the memory circuit 15.
Give to Ib. Since the memory circuit 15 writes and stores the memory peak value of the memory circuit 13 when this pulse P ₁₇ is applied, the memory peak value M ₁₅
As shown in FIG. 2h, the peak value _M13 is delayed by (Tb-Ta) time from the peak value M13 stored in the storage circuit 13. For example, when a detection voltage V _9a is generated as the detection voltage V ₉ as shown in FIG. 2a, the peak value detection circuit 10 stores the peak value |V _9a | of this detection voltage V _9a . , a pulse is generated as shown in FIG. 2c based on the pulse P _16a (time t ₁ ) shown in FIG. 2d that occurs thereafter.
P _14a (time t ₂ ) causes the peak value |V _9a | to be written and stored in the storage circuit 13, and then a pulse P _11a is generated as shown in FIG. 2b based on pulse P _14a .
(Time t ₃ ), the memory of the peak value detection circuit 10 is reset. Thereafter, based on the pulse P _16b (time t ₄ ) generated as shown in FIG. 2b, the peak value |V _9a | is stored in the memory circuit 15 by the pulse P _17a generated as shown in FIG. 2g. Written and stored. As described above, the peak value of the detection voltage V ₉ is sequentially updated and stored in the memory circuit 15, and this is provided to the determination circuit 20.

In this case, as is clear from FIGS. 2d and 2a, the generation period of the pulse P _{16 from the control pulse generation circuit 16} is the generation period of the detection voltage V ₉ , that is, as the rotation of the rotating drum rotates, the clothes are , 1, and therefore, the pulse P ₁₄ generated based on this pulse P ₁₆
The period of update memory of the memory circuits 13 and 15 that is updated and memorized by P ₁₇ and P 17 is also
It is approximately equal to the contact period of contact with
As a result, efficient detection timing can be obtained.

On the other hand, if the detection electrodes 1, 1 detect a conductor such as a metal button or fastener attached to clothing during such a drying operation, the detected electrical resistance value will be more abnormal than when detecting clothing. As shown in FIG. 2a, the detection voltage V ₉ becomes an abnormally high detection voltage V _9b close to the power supply voltage +V _cc .
Then, when this detection voltage V _9b exceeds the abnormality setting value Vs (time t ₅ ), the conductor detection section 19 generates a high-level output signal, and based on this, the delay circuit 18 is activated as shown in FIG. 2 f. As shown, a low level output signal is generated as a stop signal. Therefore, the AND circuit 17 stops generating the pulse _P17 as shown in FIG. 2g, and the memory circuit 15 stops the subsequent write update storage operation. Thereby, even if the peak value stored in the storage circuit 13 changes thereafter, the storage circuit 15 will store the peak value stored before time _t5 as is. Then the detection voltage V _9b
becomes lower than the abnormal setting value Vs (time t ₆ ), the output signal of the conductor detection section 19 changes from high level to low level, but the delay circuit 15 continues to output the low level output signal for a predetermined period of time. continues to occur, and therefore, the memory circuit 15 stops the write update storage operation even after that. Then, when a predetermined period of time has elapsed (time _t7 ), the output signal of the delay circuit 18 returns to high level, and the AND circuit 17 resumes generating the pulse _P17 .
The storage circuit 15 resumes the write update storage operation of the peak value. As a result of the above, even if the detection electrodes 1, 1 detect a conductor such as a metal button or fastener, the memory circuit 1
5 will not erroneously store this as clothing drying rate data.

In this way, when the drying rate of the clothes is small, the peak value stored in the memory circuit 15 exceeds the predetermined value Va shown in FIG. Then, the drying operation continues. Thereafter, when the drying rate of the clothes becomes high when the clothes are almost completely dried, the memory peak value of the memory circuit 15 is set to a predetermined value Va.
The determination circuit 20 generates a stop command signal when it detects that the stored peak value has been below the predetermined value Vs for a certain period of time.
The drive circuit 21 turns off the electric heater 22 and then turns off the drive motor 23 after a certain period of time, and the drying operation ends.

In the above embodiment, the configuration of the electric circuit is shown as a block diagram for convenience of explanation, but it is actually constructed by a microcomputer, and the configuration is extremely simple.

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 is provided with a detection electrode that contacts the material to be dried in the rotating drum and detects its electrical resistance value, and converts the detected electrical resistance value of the detection electrode into a drying rate data signal. A detection unit is provided to sequentially detect the peak values.
A first storage means for sequentially updating and storing the detection peak value of the detection section is provided, a second storage means is provided for sequentially updating and storing the memory value of the first storage means, and the detection electrode is made of metal or the like. A conductor detection section is provided which detects an abnormal electrical resistance value when in contact with the conductive member, generates a stop signal for a predetermined period of time, and supplies this to the second storage means to stop the update storage operation thereof, Since the memory update of the second storage means is set to be approximately equal to the contact period of the object to be dried with the detection electrode, when the detection electrode detects a conductive member, the peak value is stored in the second storage means. Therefore, it is possible to provide a drying rate detecting device for a dryer that has an excellent effect of being able to reliably detect drying rate data of the object to be dried without being affected by the conductive member.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electric circuit showing an embodiment of the present invention, and FIG. 2 is a waveform diagram of various parts for explaining the operation of the embodiment. In the drawing, 1 is a detection electrode, 2 is a rotating drum, 3 is a detection section, 10 is a peak value detection circuit, 11 is a monostable multivibrator circuit, 12 is a storage section, 13 is a storage circuit (first storage means), 14 is a monostable multivibrator circuit, 15 is a storage circuit (second storage means), 16 is a control pulse generation circuit, 18 is a delay circuit, 19 is a conductor detection section, 22 is an electric heater,
23 indicates a drive motor.

Claims (1)

[Claims] 1. A detection electrode that contacts the object to be dried in the rotating drum and detects its electrical resistance value, and a detection section that extracts the detected electrical resistance value of this detection electrode as a drying rate data signal and sequentially detects its peak value. A first storage means for sequentially updating and storing the detection peak value of the detection unit, a second storage means for sequentially updating and storing the memory value of the first storage means, and the detection electrode is made of a conductive member such as metal. a conductor detection section that detects an abnormal electrical low resistance value upon contact, generates a stop signal for a predetermined period of time, and applies this to the second storage means to stop the update storage operation thereof; 1st and 2nd
A drying rate detection device for a dryer, characterized in that the memory update of the storage means is set to be approximately equal to the contact period of the object to be dried with the detection electrode.