JPH0731794A - Clothes drier - Google Patents

Abstract

PURPOSE:To obtain a stable baffle effect extending from the beginning of drying to its end by executing phase contrtol to a drum driving motor in order to lower a drum revolving speed, based on a difference between a standard drum suspension time and an actually measured drum suspension time. CONSTITUTION:A microcomputer 21 outputs a command signal to an inversion amplifier circuit 23 so that a drum is subjected to forward rotation and backward rotation at every prescribed time, and also, detects a suspension time being the time extending from the time when the electric conduction to a drum driving motor is cut off to the stop of an inertial rotation of the drum by a timer, etc., whenever the drum executes the forward rotation to the backward rotation, or the inversion of the backward rotation to the forward rotation. Subsequently, based on the suspension time, a target value of an optimal drum revolving speed is determined, a control signal is outputted to a phase control circuit 24 in order to realize the target value, and by executing phase control of the drum driving motor, the drum revolving speed detected by a revolving speed detector 22 is allowed to coincide with the target value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clothes dryer in which a drum for containing clothes has a structure capable of normal rotation and reverse rotation.

[0002]

2. Description of the Related Art Generally, in this type of clothes dryer,
While blowing dry air or hot air into the drum containing wet clothes, the normal rotation and reverse rotation of the drum are repeated every predetermined time to increase the contact area between the clothes and the dry air, and the hot air to quickly move the clothes. It is designed to be dried.

[0003]

By the way, when the drum is switched from the normal rotation to the reverse rotation and from the reverse rotation to the normal rotation, even if the drive motor is de-energized, the drum does not stop at the same time but the inertia rotation is caused. Accompany. This inertial rotation time causes the clothes contained inside to perform a braking action on the drum as an eccentric load, so when the weight of the clothes is large, the inertial rotation time is short, but as the clothes dry and the weight becomes lighter, the inertial rotation time It takes longer time. When the inertial rotation time becomes long, the time when the clothes are exposed to the dry air and the heated air becomes short, and the area becomes small, so that it takes a long time to dry.

As a countermeasure against this, a technique for reducing the inertial rotation time of a conventional drum has been proposed (Actual development: Sho 59-183).
No. 190). In this clothes dryer, it is possible to increase the drying efficiency by shortening the inertial rotation time of the drum as much as possible and shorten the drying time, but the rotation speed of the drum is always kept constant. However, from the beginning to the end of the drying process, there is a problem that the clothing lifting effect (called baffle effect) by the baffle becomes unstable as the weight of the clothing becomes lighter.

Further, the clothes in the drum are lifted upward as the drum rotates and fall from the upper part. The clothes are lifted by the baffle effect (called baffle effect) and come into contact with the entire clothes in a large area with dry air and heated air. Drying progresses, but when the drum rotation speed is high, gravitational acceleration causes the clothes to rotate together while being pressed against the drum peripheral wall.
Since the contact area with the heated air is small, it takes a long time for drying. Furthermore, in the case of a structure that drives the drum by reducing the rotation speed of the drum drive motor by the difference in the pulley diameter, when trying to make a series of products due to the large or small capacity of the drying chamber, the difference in the power supply frequency for the drive system, Due to the difference in drum diameter, a dedicated drive system was required for each, and there was the problem that a longer development period and higher costs could not be avoided.

The present invention has been made in view of the above circumstances, and an object thereof is to change the number of rotations of the drum in accordance with the inertial rotation time of the drum, that is, the idle time of the drum, so that the initial drying is performed. We provide a clothes dryer that can obtain a stable baffle effect until the end and shorten the development period by reducing the development cost by sharing the drive system even when making a series of clothes dryers with different drum capacities. There is.

[0007]

SUMMARY OF THE INVENTION A clothes dryer according to a first aspect of the present invention includes a drum that contains clothes and is driven to rotate in the forward and reverse directions, a sensor that detects the number of rotations of the drum, and a drum driving motor. Means for obtaining a drum pause time which is the time until the inertial rotation of the drum is stopped after the energization to is stopped, a means for obtaining a standard drum pause time based on a plurality of drum pause times, and the standard drum pause time. And a means for performing phase control for the drum driving motor so as to reduce the number of rotations of the drum on the basis of the difference from the measured drum pause time.

In the clothes dryer according to the second aspect of the present invention, a drum for loading clothes, a motor for driving the drum, and a rotational speed of the motor are increased / decreased in a plurality of stages by phase control in accordance with a load capacity of the drum. And a general-purpose control board having a rotation speed setting unit for.

[0009]

According to the first aspect of the present invention, the rotation speed of the drum driving motor is reduced based on the inertia rotation time in which the load resistance of the drum is reflected. A stable baffle function can be obtained without being affected. According to the second aspect of the invention, this makes it possible to cope with various models having different drum load capacities by using a single control board in which the rotation speed setting means is set corresponding to each model. The cost and product cost can be significantly reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings showing the embodiments. (Embodiment 1) FIG. 1 is a front view of a clothes dryer equipped with a drum rotation speed control device according to the present invention, and FIG. 2 is a rear view of the same, in which 1 is a machine frame, and 2 and 3 are upper and lower. Drying room, 4 is above,
It is an operation panel section that is also used for the lower drying chamber. Each of the drying chambers 2 and 3 is provided with an outer tub and a drum (not shown) pivotally supported in the outer tub, and a front surface of each of the drying chambers 2 and 3 is provided with a clothes inlet for the drum. The doors 2a and 3a can be opened and closed.

Further, pulleys 5 and 6 are provided on the rear shaft of the rotary drum as shown in FIG. 2, and the pulleys 5 and 6 are provided on the output shafts of the motors M ₁ and M ₂ via belts 7 and 8, respectively. Are connected to the pulleys 9 and 10, and the motors M ₁ and M
_The drum can be rotated forward and backward by the forward and reverse rotation of ₂ . The operation panel section 4 includes individual coin insertion openings 4a and 4b for operating the upper and lower drying chambers 2 and 3, an indicator 4c for displaying the amount of coins inserted, and other control boards (not shown). I have it. Others 11 and 12 are heaters, and the heated air is introduced into the drum by a fan driven by motors M ₃ and M ₄ , and the exhaust port 1
It is designed to be discharged backward from 3,14.

A rotation speed detector 22 (see FIG. 3) for detecting the rotation speed is provided on the output shafts of the drum driving motors M ₁ and M ₂ . The rotation speed detector 22 has choppers attached to the drum driving motors M ₁ and M ₂ , and detects the rotation speed by a pulse input when the chopper crosses the photo interrupter. Of course, the present invention is not limited to this, and a small generator may be attached to the output shaft of the motor to detect the generated voltage, or may be detected using a reed switch or a hall element.

FIG. 3 is a block diagram showing a drum drive control system of a drum rotation speed control device for a clothes dryer according to the present invention. In the figure, 21 is a microcomputer, 22 is a drum drive motor M ₁ , M ₂ . A rotation speed detector for detecting the rotation speed, specifically, the rotation speed of the pulleys 9 and 10 provided on the output shaft of the motor, and 23 is a reversal drive for causing the drum driving motors M ₁ and M ₂ to perform forward and reverse rotations. Circuit, 24 is a drum driving motor M ₁ ,
It is a phase control circuit for controlling the rotation speed of M ₂ .

The microcomputer 21 includes an inversion drive circuit 23.
On the other hand, a command signal is output to repeat the normal rotation and the reverse rotation of the drum at a predetermined time, and the power supply to the drum drive motor is cut off each time the drum reverses from the normal rotation to the reverse rotation or from the reverse rotation to the normal rotation. The rest time, which is the time from the moment when the inertial rotation of the drum is stopped, is detected by a timer, etc., the target value of the optimum drum speed is determined based on this rest time, and this decided target value is realized. To output a control signal to the phase control circuit 24, the drum drive motor M
_The drum rotation speed detected by the rotation speed detector 22 is matched with this target value by performing the phase control of ₁ and M ₂ .

The phase control of the drum driving motors M ₁ and M ₂ is specifically performed as follows. The drum driving motors M ₁ and M _{2 respectively} repeat normal rotation and reverse rotation to rotate the drum forward and reverse at predetermined time intervals. When switching from normal rotation to reverse rotation or from reverse rotation to normal rotation, The time from when the power supply to the drum driving motor is cut off until the pulse is no longer input from the rotation speed detector 22 to the input terminal of the microcomputer 21, that is, the rest time is measured using a timer or the like. The arithmetic average value T ₁ of the drum pause times from the start of the operation to the first 5th time is calculated and used as the standard pause time.

Next, the 6th drum dwell time from the beginning is measured, and this is set as the measured drum dwell time T _2, and the rotation speed is reduced at each dwell time so that this value becomes approximately T ₁ by the end of the operation. Let me let you go. The control of the drum rotation speed is performed by changing the position of the phase control circuit of the drum driving motors M ₁ and M ₂ , that is, the conduction point of the phase control angle. That standard pause as the time the initial setting angle theta ₁ of the phase angle for controlling the rotational speed corresponding to T _1, 6 th actual drum downtime in correspondence with T ₂ phase angle theta ₁ of theta ₂ Change to.

For example, when T ₁ <T ₂ , the value of T ₂ is reduced by increasing θ ₂ by 2 °, and this is repeated until T ₁ = T ₂ . Note the difference between T ₁ and T ₂ is time consuming in the correction of the 2 ° increments too large, when the T ₂ until dry end there is a possibility that can not be sufficiently close to T ₁ is, theta ₂ Is increased by 5 ° to shorten the time until T ₁ = T ₂ . Hereinafter, the drum drive motor M ₁ ,
The measured drum pause time is calculated every time the M ₂ rotation direction is switched,
The above processing is repeated according to the difference from the standard rest time. As the standard pause time, for example, a value obtained by obtaining the arithmetic mean value of the five actually measured pause times including the smallest number in the memory storage order may be used.

FIG. 4 and FIG. 5 are flowcharts showing the processing steps in the drum rotation speed control device for the clothes dryer according to the present invention. It is judged whether or not the operation is completed (step S1).
If the operation is completed, the operation is stopped (step S2) .If the operation is not completed, air heating control processing by a burner or the like is performed (step S3), and reversal control processing for the drum is performed.
(Step S4), and determines the standard downtime T ₁ of the drum based on the drum resting time from the first up to the fifth (step
S5). The rotation speed θ ₁ is set to a new rotation speed θ ₂ (step S6), and the phase control process is performed (step S7).

FIG. 5 is a flow chart showing the specific contents of the phase control process. It is judged whether or not the set time T ₁ = T ₂ (step S11). If T ₁ = T ₂ , the process ends, and T ₁ = T _2.
1 ≠ T ₁ to determine the difference between T ₁ and T ₂ in the case of T ₂
It is determined whether or not + 5 ≦ T ₂ (step S12), and when this condition is satisfied, the value obtained by adding “5” to θ ₁ is set as θ _2.
(Step S13), and if not satisfied, θ ₁ is “2”
The value obtained by adding is set as θ ₂ (step S14).

In the first embodiment, the drum rotation speed is
An appropriate value is determined based on the drum idle time at the time of switching between normal and reverse rotations, and phase control is performed on the drum drive motor so as to gradually decrease the drum rotation speed so that the measured rotation speed of the drum gradually approaches the appropriate value. . As a result, a stable baffle effect can be obtained by controlling the number of rotations of the drum in response to a change in the drum pause time that reflects the load amount, which is the weight of clothes in the drum.

(Embodiment 2) This embodiment 2 is a single control board for each model when the product has a series of clothes dryers having different drying capacities, that is, different drum diameters. It is possible to deal with. FIG. 6 shows a second embodiment of the present invention.
FIG. 3 is a block diagram showing a main control system on the control board in FIG. The microcomputer 31 receives the coin insertion information from the coin switch circuit 32, the door opening / closing information from the door switch 33, the presence / absence of reset or reset release from the reset switch 34, the dip information from the dip switch 35, and the further drum information. Temperature information is taken in from a thermistor 36 provided at the air inlet and a thermistor 37 provided at the air outlet from the drum, and pulse information corresponding to the number of revolutions is taken in from a revolution number detector 38. Further, each information is taken in from the power supply circuit 41 connected to the backup detection circuit 39, the power failure detection circuit 40, and the commercial power supply 42, and the clock is taken in from the clock oscillation circuit 43.

Then, based on these captured information,
The microcomputer 31 interposes a load drive circuit 44 to the drum drive circuit to instruct forward rotation and reverse rotation commands, and to drive and stop fan motors M ₃ and M ₄ , respectively, and further to the igniter 4
5. The command for the gas valve 46 and the safety valve 47 is output, and the temperature, drum rotation speed, etc. are displayed on the display 48.

The dip switch 35 indicates the basic rotational speed of the drum, for example, ± 0, +1, +2, +3, -1, -2, -3.
It is possible to increase and decrease as shown. Normally, when the drum diameter increases, the drum rotation speed is set to a value obtained by subtracting α from the basic rotation speed n, and when the diameter becomes small, the drum rotation speed is set to a value obtained by adding α to the basic rotation speed n. As a result, the same control board is installed for each model with different drum diameter,
This can be dealt with by setting the DIP switch 35 appropriately.

Usually, there is the following relationship between the gravitational acceleration G, the drum radius r, and the number of rotations n of the drum. G = 1.119 × r × n ² × 10 ^-3 Therefore, by setting the rotation speed n appropriately and rotating,
The clothes do not co-rotate with the drum, but spread inside the drum and can be brought into contact with the hot dry air over a large area.
Normally, the optimum value of gravity acceleration G is about 0.8.

[0025]

As described above, according to the first aspect of the present invention, regardless of the degree of progress of drying of clothes, the drum is always driven to rotate at an appropriate number of rotations. Since it is lifted up and dropped in a spread state, the contact area with dry air or the like is increased, and there is an effect that it can be dried efficiently. Further, according to the second aspect of the present invention, since a common control board for the clothes dryer having different drum load capacities can be used, an excellent effect that the development cost can be significantly reduced can be obtained.

[Brief description of drawings]

FIG. 1 is a front view of a clothes dryer to which the present invention is applied.

FIG. 2 is a rear view of the clothes dryer to which the present invention is applied.

FIG. 3 is a block diagram showing a main control system of a clothes dryer to which the present invention is applied.

FIG. 4 is a flowchart showing a drum rotation speed control process in the drum rotation speed control device for a clothes dryer according to the present invention.

FIG. 5 is a flowchart showing a drum rotation speed control process in the drum rotation speed control device for the clothes dryer according to the present invention.

FIG. 6 is a block diagram showing a main control system in another embodiment of the present invention.

[Explanation of symbols]

1 device frame 2,3 drying chamber 4 the operation panel unit 5, 6 pulleys 7,8 belt 9,10 pulleys 11,12 heater M _1, M ₂ the drum driving motor 21 microcomputer 22 rotational speed detector 23 inversion drive circuit 31 Microcomputer 32 Coin switch circuit 33 Door switch 34 Reset switch 35 DIP switch 36,37 Thermistor 40 Power failure detection circuit

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[Procedure amendment]

[Submission date] September 21, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

[0003]

By the way, when the drum is switched from normal rotation to reverse rotation and vice versa, even if the drive motor is de-energized, the drum does not stop at the same time and inertial rotation is caused. Accompany. This inertial rotation time causes the clothes contained inside to perform the braking action on the drum as an eccentric load, so the inertial rotation time is short when the weight of the clothes is large, but as the clothes dry and the weight becomes lighter, the inertial rotation time becomes shorter. It takes longer time. At this time, drive
If the time to cut off the power to the dynamic motor is constant,
The inertial rotation time that occupies the power interruption time is
Shorter and longer as drying progresses. In other words, energize
During the cutoff time, after inertial rotation has stopped,
Drum stop time until the ram next reverses, start drying
Initially long, it becomes shorter as the drying progresses. Therefore, dry
At the beginning of drying , the clothes are in a stationary state for a long time, the time during which the clothes are exposed to the dry air and the heated air is short, and the area is small, so that the drying takes a long time.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

As a countermeasure against this, conventionally , the drum stop time is
The technology to solve the problem has been proposed (Actual exploitation 59-18319
No. 0 bulletin). In this clothes dryer, it is possible to improve the drying efficiency by shortening the stationary time of the clothes in the drum as much as possible, and the drying time can be shortened, but the rotation speed of the drum is always kept constant. Therefore, from the beginning to the end of the drying process, there is a problem that the clothing lifting effect (called baffle effect) by the baffle becomes unstable as the weight of the clothing becomes lighter.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

FIGS. 4 and 5 are flowcharts showing the processing steps in the drum rotation speed control device for a clothes dryer according to the present invention. It is judged whether or not the operation is completed (step S1),
When the operation is completed, the operation is stopped (step S2), and when the operation is not completed, the air heating control process by the burner etc. is performed (step S3), and the reversal control process for the drum is performed.
(Step S4), and determines the standard downtime T ₁ of the drum based on the drum resting time from the first up to the fifth (step
S5). The phase angle θ ₁ is set to a new phase angle θ ₂ (step S6), and the phase control process is performed (step S7).

Claims (2)

[Claims] 1. A drum which accommodates clothes and is driven to rotate in the forward and reverse directions, a sensor for detecting the number of rotations of the drum, and after the power supply to the drum driving motor is cut off, the inertial rotation of the drum is stopped. Up to a drum dwell time, a means for finding a standard drum dwell time based on a plurality of drum dwell times, and a drum rotation speed based on the difference between the standard drum dwell time and the measured drum dwell time. And a means for performing phase control on a drum driving motor to lower the temperature. 2. A general-purpose having a drum for putting in clothes, a drum driving motor, and a rotation speed setting means for adjusting the rotation speed of the motor in a plurality of steps by phase control in accordance with the load capacity of the drum. A clothes dryer, comprising: a control board.