JP3026654B2 - Centrifugal dehydrator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal dehydrator for dehydrating laundry.

[0002]

2. Description of the Related Art Conventionally, this type of centrifugal dehydrator is disclosed in
No. 236092. In this device, the dehydration tank is rotated by the condenser motor, the capacitor voltage immediately after the dehydration operation is stored, and then the capacitor voltage is sequentially detected and compared with the stored value, and the capacitor voltage becomes higher by a predetermined value than the stored value. For example, the power supply to the condenser motor is stopped for a predetermined time, and the rotation of the dehydration tub is kept constant.

[0003]

In the above conventional example,
Usually, since the laundry is in the middle of the dehydration tub, the dehydration tub can be rotated at the set rotation speed, but if the laundry is offset in the dehydration tub, when the dehydration tub is rotated, Since the laundry is farther away from the center of rotation of the spin tub, and the spin tub swings further, the rotating moment increases,
As a result, the motor requires a large rotational torque, and as a result, the rotational speed of the motor decreases. When the number of rotations decreases, the number of rotations of the dehydration tub also decreases, so that the target dehydration rate cannot be achieved, and it takes time for subsequent drying.

[0004] The present invention solves such a problem.

[0005]

Means of the present invention for solving the problems include: a motor for rotating a rotatably supported dehydration tub at a high speed; rotation detecting means for detecting the number of rotations of the motor; comparison means for comparing the detected value with a set value of the rotation detecting means, a timer for counting the dehydration time, operation start early the motor and intermittent operation, the timer with switch to subsequent continuous operation has counted up And control means for ending the operation.
The control unit is configured to detect the rotation when the motor is turned off.
Detecting the rotational speed by known means, if you get the result that this <br/> detected value by said comparing means is smaller than the set value, is configured to extend the dewatering time of the timer.

[0006]

[0007]

In other words, when the rotation of the spin tub is detected by the rotation detecting means while the motor is de-energized, and the detected value is compared with the set value by the comparing means, there is usually laundry near the middle of the spin tub. Therefore, the result is obtained that the rotation speed is larger than the set value. If this result is obtained, the operation ends when the timer counts up the spin-drying time.

However, if the laundry is placed in the dewatering tub with a bias, the laundry is separated from the rotation center of the dehydration tub, and the dehydration tub swings greatly, so that the rotating moment applied to the motor increases. Therefore, a large rotating torque is required, and the number of rotations is reduced accordingly. Therefore, since the rotation speed of the dewatering tub decreases, it is determined by the comparing means that the rotation speed is smaller than the set value, and the dewatering time is extended to obtain the same dewatering rate as in a normal case.

[0009]

In FIG. 1, reference numeral 1 denotes a key input unit for inputting an instruction related to washing, 2 denotes a microcomputer control unit for converting an instruction input by the key input unit 1 into a signal, and 3 denotes control contents of the microcomputer control unit 2. , A control result is displayed using characters and figures, and an LED display unit 4 for guiding the user to the progress and the like is a safety switch for detecting the open / closed state of the upper lid of the dehydration tank. Reference numerals 5 and 6 denote triacs, 7 denotes a condenser for operating a motor 8 for rotating the dehydration tub, and 9 denotes a memory for storing a dehydration time T. Note that the microcomputer control section 2 includes a timer 10 for counting the dehydration time T and a comparing means 11.

Reference numeral 12 denotes opening of a drain valve (not shown),
A solenoid that releases a dehydration brake (not shown),
Reference numeral 13 denotes a signal conversion circuit that detects a voltage generated at both ends of the capacitor 7 and converts the voltage into a pulse signal. Reference numeral 14 denotes a DC power supply circuit that supplies DC power to the microcomputer control unit 2. Reference numeral 15 denotes an open circuit for supplying water to the dewatering tank. The water supply valve 16 is a buzzer for notifying the end of the dehydrating operation and an abnormal time.

The dehydrating operation will be described with reference to FIG. First, the microcomputer controller 2 turns on the solenoid 12 to open the drain valve and release the dehydration brake (S-1). Thereafter, the triac 5 is turned on, and the motor 8 is energized to rotate the dehydration tub (S-2). After a lapse of 8 seconds, the triac 5 is turned off for 3 seconds to cut off the power supply to the motor 8 (S-3). During that time, the dewatering tub keeps rotating by inertia.

At this time, an induced voltage is generated across the capacitor 7 by the magnetism of the rotor of the motor 8. As shown in FIG. 3, this induced voltage has a longer period as the rotation speed of the rotor decreases.

This signal is given to a signal conversion circuit 13 to
And the pulse signal is given to the microcomputer control unit 2. The microcomputer control unit 2 counts the number of pulse signals provided from the signal conversion circuit 13 (S-4).

After the triac 5 is turned off for 3 seconds, the triac 5 is turned on again, and the same operation as described above is performed three more times.

When the continuous dehydration is performed from the beginning without performing the above-mentioned intermittent dehydration at the start of dehydration, since the laundry contains a large amount of water, the dehydration tub swings greatly, and the dehydration tub is shaken. A large load is applied to a shaft connecting the motor 8 and the like.
Therefore, intermittent dehydration is performed to dehydrate water from the laundry to some extent, and then shift to continuous dehydration to reduce the swing of the dehydration tub so as not to burden the connecting shaft and the like.

After the motor 8 is turned on for 8 seconds and intermittent dehydration for 3 seconds is repeated four times (S-5), the microcomputer controller 2 reads the dehydration time T from the memory (S-6).
At the same time, the sum P of the number of pulse signals counted in each intermittent dehydration is compared with 32, which is the set value in the present embodiment, by the comparing means 11 (S-7).

At this time, if the laundry is solidified in the vicinity of the center of the dehydration tub, the distance of the laundry from the rotation center of the dehydration tub is not too large, and the laundry is obtained by multiplying the weight of the laundry by the distance from the rotation center. Since the required rotational moment is not so large, a large rotational torque is not required. Accordingly, the rotation speed of the dewatering tank is set (850 rpm to 860 rpm).
, An appropriate number of inertial rotations of the dehydration tub is obtained, and the total P of the counted pulse signals is more than 32.

However, if the laundry is offset in the dehydration tub, the laundry will be separated from the rotation center of the dehydration tub,
As a result, the rotational moment increases and the motor 8
Therefore, the rotation speed of the motor 8 is reduced. Therefore, since the rotation speed of the dehydration tub is smaller than the set rotation speed, the inertial rotation speed of the dehydration tub also decreases,
The sum P of the counted pulse signals is less than 32.

As a result of the comparison by the comparing means, if the total P is 32 or more, the dehydration time T is set in the timer 10 (S-9).
The time obtained by adding the minutes (S-8) is set in the timer 10 (S-9).

When the dehydration time T is set in the timer 10, the triac 5 is turned on to continuously energize the motor 8 (S-10), and the timer 10 starts counting (S-11) to start the dehydration operation. . When the timer 10 counts up, the triac 5 is turned off and the motor 8
Then, the power supply to is stopped (S-12), and the spin-drying operation ends.
At this time, the buzzer 16 is driven to notify the end.

From the above, when the inertia rotation speed of the motor 8 is low, it is determined that the laundry in the dehydration tub is offset, and the dehydration time T is extended by one minute, and the dehydration rate is the same as that in the normal dehydration. Is obtained.

[0022]

According to the present invention, even if the laundry in the dewatering tub is shifted, the dewatering time of the dewatering tub is extended, so that the dewatering rate can be kept constant.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a washing machine of the present invention.

FIG. 2 is a flowchart showing a dehydrating operation of the washing machine of FIG.

FIG. 3 is a diagram showing an input signal of a signal conversion circuit in FIG. 1;

FIG. 4 is a diagram showing output signals of a signal conversion circuit in FIG. 1;

[Explanation of symbols]

 2 microcomputer control unit (control means) 8 motor 10 timer 11 comparison means 13 signal conversion circuit (rotation detection means)

Continuation of front page (56) References JP-A-57-115297 (JP, A) JP-A-62-277998 (JP, A) JP-A-55-136093 (JP, A) JP-A-60-48791 (JP, A) , A) JP-A-63-164994 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D06F 33 / 02,49 / 04

Claims (1)

(57) [Claims] 1. A motor for rotating the rotatably supported dewatering tank at a high speed, a rotation detecting means for detecting the rotational speed of the motor, comparing means for comparing the detected value with a set value of the rotation detecting means when the timer for counting the dehydration time, operation start early the motor and intermittent operation, in what comprising a control means for terminating the operation when the timer has counted up with switching to subsequent continuous operation,
The control unit is configured to detect the rotation when the motor is turned off.
Detecting the rotational speed by known means, if you get the result that this <br/> detected value by said comparing means is smaller than the set value, the centrifugal dehydrator was characterized by extending the dewatering time of the timer.