JP3096540B2 - Clothes dryer - Google Patents

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 accommodating 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 the wet clothes, the drum rotates forward and backward repeatedly at predetermined time intervals to increase the contact area between the clothes and the dry wind and hot air, and to quickly remove the clothes. It is configured to be dried.

[0003]

By the way, when the drum is switched from normal rotation to reverse rotation and from reverse rotation to normal rotation, even if the power supply to the drive motor is cut off, the drum does not stop at the same time, but the coasting rotation is started. Accompany. The inertia rotation time is such that the clothing contained therein acts as a brake to the drum as an eccentric load, so when the clothing weight is large, the inertia rotation time is short, but as the clothing dries and the weight decreases, the inertia rotation occurs. The time will be longer. At this time,
If the time to cut off the power to the dynamic motor is fixed,
The inertia rotation time in the power-off time is initially
Shorter, longer as drying progresses. In other words, electricity
During the shutoff time, after the inertial rotation has stopped,
Drum stop time before ram reverses
It is initially long and becomes shorter as 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 a long time is required for drying.

As a countermeasure against this, conventionally , the stopping time of the drum
Technology has been proposed to solve the problem
No. 0). In this clothes dryer, it is possible to increase the drying efficiency by shortening the rest time of the clothes in the drum as much as possible and shorten the drying time, but the rotation speed of the drum is always kept constant. Therefore, during the period from the beginning to the end of the drying process, there is a problem that the clothes lifting effect (baffle effect) by the baffle becomes unstable as the weight of the clothes decreases.

The clothes in the drum are lifted upward with the rotation of the drum and fall from the upper part. The clothes are lifted by a baffle effect (baffle effect) and come into contact with the whole of the clothes in a large area with dry air and heated air. Drying proceeds, but when the drum rotation speed is high, the clothes rotate together with the drum pressed against the peripheral wall of the drum due to gravitational acceleration.
The contact area with the heated air is small, and a long time is required for drying. Furthermore, in the case of a structure in which the number of rotations of the drum drive motor is reduced by the difference in the pulley diameter to drive the drum, when attempting to make a series of products by increasing or decreasing the capacity of the drying chamber, the difference in power supply frequency to the drive system, Due to the difference in the diameter of the drum, a dedicated drive system is required for each, and there is a problem that the development period is prolonged and the cost is inevitably increased.

The present invention has been made in view of the above circumstances, and an object of the present invention is to change the number of rotations of the drum in accordance with the inertial rotation time of the drum, that is, the drum pause time, so that the drum can be dried from the beginning of drying. Providing a clothes dryer that can obtain a stable baffle effect until the end of the process and also enables the development system to be shortened and the development cost to be reduced by sharing the drive system even when a series of clothes dryers with different drum capacities are made into a series. To be.

[0007]

According to a first aspect of the present invention, there is provided a clothes dryer including a drum for accommodating clothes and driven forward and backward, a sensor for detecting the number of revolutions of the drum, and the dryer. Drum drive motor for rotating the drum and this drum drive
After the power supply to the motor is cut off,
Calculate the drum pause time, which is the time until the rotation stops
Means and the drum pause reflecting the load in the drum
Means for controlling the drum driving motor to reduce the number of rotations of the drum as the load becomes lighter based on time .

[0008]

According to the present invention, the baffle function is stabilized without being affected by the progress of the drying of the clothes and the like, since the rotation speed of the drum is reduced as the weight of the clothes is reduced as the drying progresses. Is obtained.
Further, the drum rotation speed decreases as the drying proceeds, so that even if the weight changes due to the drying of the clothes, the inertial rotation time does not change.

[0010]

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, FIG. 2 is a rear view thereof, wherein 1 is a machine frame, and 2, 3 are upper and lower. Drying room, 4 is above,
This is an operation panel for the lower drying room. 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 clothing inlet for the drum is provided on a front surface of each of the drying chambers 2 and 3. , And can be opened and closed by doors 2a and 3a.

As shown in FIG. 2, pulleys 5 and 6 are provided on the rear shaft of the rotary drum, and the pulleys 5 and 6 are provided on output shafts of motors M ₁ and M ₂ via belts 7 and 8, respectively. Motors M ₁ , M
_The drum can be rotated forward and backward by the forward and reverse rotation of ₂ . The operation panel unit 4 includes individual coin insertion slots 4a and 4b for operating the upper and lower drying chambers 2 and 3, an indicator 4c for displaying the amount of inserted coins, and other control boards (not shown). Have. Others 11 and 12 are heaters, and the heated air is introduced into the drum by fans driven by motors M ₃ and M ₄ , and the exhaust port 1
3,14 from the rear.

The output shafts of the drum driving motors M ₁ and M ₂ are provided with a rotation speed detector 22 (see FIG. 3) for detecting the rotation speed. The rotation speed detector 22 has a chopper attached to the drum driving motors M ₁ and M ₂ , and detects a rotation speed by 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 the apparatus for controlling the number of revolutions of a drum of a clothes dryer according to the present invention. In FIG. 3, reference numeral 21 denotes a microcomputer, and 22 denotes drum drive motors M ₁ and 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 a reverse drive 23 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 ,
A phase control circuit for the rotational speed control of M _2.

The microcomputer 21 includes an inversion drive circuit 23
Output a command signal to repeat the forward and reverse rotations of the drum at predetermined intervals, and cut off the power to the drum drive motor every time the drum switches from forward rotation to reverse rotation or from reverse rotation to normal rotation. The pause time, which is the time from when the drum is stopped to the time when the coasting of the drum stops, is detected by a timer or the like, and based on the pause time, the optimal target value of the drum rotation speed is determined, and the determined target value is realized. Output a control signal to the phase control circuit 24 so that the drum driving motor M
_1, and to perform the phase control of the M ₂ match drum rotation speed detected by the rotational speed detector 22 to the target value.

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 repeat forward and reverse rotations at predetermined time intervals to rotate the drum forward and reverse, however, when switching from forward rotation to reverse rotation or from reverse rotation to normal rotation, The time from when the power 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 pause time is measured using a timer or the like. Calculated an arithmetic mean value T ₁ of the first drum downtime until 5 th from operation start time, this is a standard downtime.

Next, the sixth drum pause time from the beginning is actually measured, and this is taken as an actually measured drum pause time T _{2. The} rotation speed is reduced at each pause time so that this value becomes substantially equal to T ₁ by the end of operation. Let me do it. The control of the number of rotations of the drum is performed by changing the phase control circuit of the drum driving motors M ₁ and M ₂ , that is, the position of 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 in increments of 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 °, and the time until T ₁ = T ₂ is shortened. Hereinafter, the drum driving motor M ₁ ,
Obtains the measured drum downtime every time the rotational direction switching of M _2,
The above processing is repeated according to the difference from the standard pause time. As the standard pause time, for example, a value obtained by calculating an arithmetic average value of five actually measured pause times including the number with the smallest storage order in the memory may be used.

FIG. 4 and FIG. 5 are flow charts showing the processing steps in the apparatus for controlling the number of revolutions of the drum of the clothes dryer according to the present invention, in which it is determined whether or not the operation has ended (step S1).
When the operation is completed, the operation is stopped (Step S2). When the operation is not completed, the air heating control processing by a burner or the like is performed (Step S3), and the inversion 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). Set the phase angle theta ₁ to the new phase angle theta ₂ (step S6), and performs a phase control process (step S7).

FIG. 5 is a flowchart showing the specific contents of the phase control process. It is determined whether or not the set time T ₁ = T ₂ (step S11). If T ₁ = T ₂ , the process is terminated.
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). If this condition is satisfied, a value obtained by adding “5” to θ ₁ is set as θ _2.
(Step S13) If it does not hold, " ₁ " is set to θ1.
A value obtained by adding the set and theta ₂ (step S14).

In the first embodiment, the rotational speed of the drum is
The appropriate value is determined based on the drum pause time at the time of switching between the forward and reverse rotations, and phase control is performed on the drum driving motor so as to gradually reduce the drum rotation speed so that the actually measured drum rotation speed gradually approaches this appropriate value. . As a result, a stable baffle effect can be obtained by controlling the number of rotations of the drum in accordance with the change in the drum pause time reflecting the load amount, which is the weight of the clothes in the drum.

(Embodiment 2) This embodiment 2 has a single control board for each model when a clothes dryer is made into a series of products with different drying capacities, that is, different drum diameters. Is available. FIG. 6 shows a second embodiment of the present invention.
3 is a block diagram showing a main control system on a control board in FIG. The microcomputer 31 receives coin insertion information from the coin switch circuit 32, door opening / closing information from the door switch 33, reset / reset release from the reset switch 34, dip information from the dip switch 35, and Temperature information is fetched from a thermistor 36 provided at the air inlet and a thermistor 37 provided at the air outlet from the drum, and pulse information according to the rotation speed is fetched from the rotation speed detector 38, respectively. In addition, it acquires respective information from the backup detection circuit 39, the power failure detection circuit 40, and the power supply circuit 41 connected to the commercial power supply 42, and further acquires a clock from the clock oscillation circuit 43.

Then, based on these information,
The microcomputer 31 sends forward and reverse rotation commands to the drum drive circuit via the load drive circuit 44, and also issues drive and stop commands to the fan motors M ₃ and M ₄ , and further sends the igniter 4
5. A command for the gas valve 46 and the safety valve 47 is output, and the temperature, the number of revolutions of the drum, and the like are displayed on the display 48.

The dip switch 35 controls the basic rotation speed of the drum, for example, ± 0, +1, +2, +3, -1, -2, -3.
It can be adjusted up and down like. 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 decreases, the drum rotation speed is set to a value obtained by adding α to the basic rotation speed n. This allows the same control board to be installed for each model with a different drum diameter,
By setting the dip switch 35 appropriately, it is possible to cope with the situation.

Normally, the following relationship exists between the gravitational acceleration G, the drum radius r, and the number of revolutions n of the drum. G = 1.119 × r × n ² × 10 ^-3 Therefore, by appropriately setting the rotation speed n and rotating,
The clothes spread in the drum without rotating around the drum, and can be brought into contact with the high-temperature dry air over a wide area.
Normally, the appropriate value of the gravitational acceleration G is about 0.8.

[0025]

As described above, in the present invention, the drum is always driven to rotate at an appropriate rotation speed regardless of the degree of drying of the clothes, and the clothes are lifted in the drum. As a result, it falls in an unfolded state, so that the contact area with dry air or the like increases, and there is an effect that drying can be performed efficiently. Further, since the inertia rotation time does not change depending on the degree of progress of the drying, the problem that the time during which the clothes are at rest can be solved, and the drying can be performed efficiently.

[Brief description of the 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 the clothes dryer to which the present invention is applied.

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

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

FIG. 6 is a block diagram showing a main control system according to 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

Continuation of the front page (56) References JP-A-1-119298 (JP, A) JP-A-59-26929 (JP, A) JP-A-4-338497 (JP, A) JP-A-58-192951 (JP) , A) JP-A-4-240496 (JP, A) JP-A-58-145196 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) D06F 58/28

Claims (1)

(57) [Claims] A drum for accommodating clothing and driven forward and backward, a sensor for detecting the number of rotations of the drum, a drum driving motor for rotating the drum, and a drum drive for driving the drum.
After the power to the motor is cut off,
Find the drum pause time, which is the time until rotation stops
And the drum rest reflecting the load in the drum.
Means for controlling the drum driving motor to reduce the drum rotation speed as the load decreases based on the stop time .