JP2014033833A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve silencing during dewatering by eliminating an electromagnetic sound generated by performing phase control for controlling the number of rotations of a motor during a dewatering step of a washing machine.SOLUTION: In a washing machine, energization on/off to a motor 46 for controlling the number of rotations of a motor 46 which rotates a rotary tub 42 in which laundry is put is performed at a zero-cross time of an AC power supply during a dewatering step. The generation of an electromagnetic sound from the motor 46 is suppressed, and the generation of noise during dewatering of the washing machine can be suppressed.

Description

  The present invention relates to a washing machine having a dehydrating function for dehydrating laundry stored by rotating a rotating tub at high speed.

  In conventional dehydration control of a washing machine, phase control is performed in order to keep the dehydration speed constant and stabilize the dehydration rate and dewatering efficiency regardless of the power supply frequency (see, for example, Patent Document 1).

  3 and 4 show the internal configuration of a general washing machine and its dehydration control steps. The configuration will be described below. In the outer box 1 of the washing machine, an outer tub 2 is disposed so as to be swingable via an elastic suspension mechanism 3. A rotating tub 4 serving as both a dehydrating tub and a washing tub is rotatably disposed in the outer tub 2, and a washing stirrer 5 is rotatably provided on the inner bottom of the rotating tub 4. ing. The rotating tub 4 has a dewatering hole 4a formed only in the upper part of the peripheral wall portion, and no dewatering hole is formed in the other peripheral wall portions.

  A drainage passage 6 is provided at the inner bottom of the outer tub 2 so as to extend from the center to the rear side. An end portion of the drainage passage 6 is a drainage port 7, and the drainage port 7 is configured to be opened and closed by, for example, a motor-type drainage valve 9. The stirring member 5 has a large number of water holes.

  On the other hand, on the outer bottom of the outer tub 2, a motor 16 and a drive mechanism 17 for washing and dehydrating operations are arranged. The motor 16 is an induction motor, and the rotational force of the motor 16 is transmitted to the drive mechanism unit 17 via the belt transmission mechanism 18. The belt transmission mechanism 18 is configured by stretching a belt 18c between a drive pulley 18a provided on the motor 16 side and a driven pulley 18b provided on the drive mechanism portion 17 side.

  About the conventional washing machine of the said structure, the operation | movement in a spin-drying | dehydration process is demonstrated. In FIG. 4, the dehydration process is started, and when the detected rotational speed N reaches the first target rotational speed N1, the process proceeds to step A6 according to “YES” in step A5, and the timer 2 sets the first preset value. A set fall time t1 (for example, 8 seconds) is set. Next, in step A7, the output of the motor 16 is controlled to 20% by controlling the power supplied to the motor 16 by phase control.

  This phase control is shown in FIG. 1 as FIG. 1A so that the comparison with the present invention is easy. As shown in FIG. 1A, the energization rate (energization angle) α is controlled to be 20% in the case of full energization (100%). By controlling the output of the motor 16 to 20%, the rotational speed of the motor 16 and thus the rotating tub 4 is lowered. Further, although the power supplied to the motor 16 is constant at 20%, the power supplied to the motor 16 can be changed according to the rotation speed of the motor 16 (rotation speed of the rotating tub 4).

Japanese Patent Laid-Open No. 11-179094

However, with such a conventional washing machine dewatering control method, there is a problem that voltage fluctuation increases when the motor is energized on / off, electromagnetic noise is generated, and noise is generated when the washing machine is dewatered. .

  The present invention solves the above-described conventional problems. In the washing machine dehydration control system, the energization of the motor is turned on / off at the time of zero crossing of the AC power supply to suppress electromagnetic noise, and during washing machine dehydration. It achieves noise reduction.

  The washing machine of the present invention controls the generation of electromagnetic noise from the motor by performing on / off of power to the motor at the time of zero crossing of the AC power supply in the washing machine dehydration control method, and noise is generated when the washing machine is dehydrated. Generation | occurrence | production can be suppressed.

(A) The figure which shows the phase control which is the dehydration control system of the conventional washing machine (b) The figure which shows the dehydration control system of the washing machine of Embodiment 1 of this invention Side sectional view of the washing machine according to Embodiment 1 of the present invention. Side sectional view of a conventional washing machine Flow diagram showing dehydration control steps of a conventional washing machine

  The first invention includes a housing, a rotating tub into which laundry is put, a water tub that accommodates the rotating tub and is supported from the housing by an elastic support mechanism, and the rotating tub is fixed to one end to be freely rotatable. A rotating shaft fixed to the water tank, a motor fixed to the outer bottom of the water tank, a series of processes such as washing, rinsing, dewatering and drying, and a control means for controlling the rotation of the motor, and a driven fixed to the other end of the rotating shaft A pulley, a belt that transmits the rotation of the motor to the driven pulley, a rotation detection unit that detects the number of rotations of the motor, and a zero cross detection unit that detects a zero cross of the AC power supply. Depending on the number of rotations of the motor, the generation of electromagnetic noise from the motor is suppressed by turning on / off the motor during the zero cross of the AC power source obtained from the zero cross detection means during the dehydration process. It is possible to suppress that the noise is generated at the time of dehydration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Further, the present invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 (FIG. 1 (b)) is a diagram showing a dehydration control method for a washing machine according to Embodiment 1 of the present invention, and FIG. 2 is a side sectional view of the washing machine according to Embodiment 1 of the present invention.

  In FIG. 2, a casing 41 of the washing machine accommodates a rotating tub 42 into which laundry is put, and a water tub 44 that accommodates the rotating tub 42 and is supported by the elastic support mechanism 43 from the casing 41.

  A rotating shaft 45 that is rotatably fixed to the bottom of the water tank 44 has a rotating tank 42 fixed at one end and a driven pulley 48 fixed at the other end. The driven pulley 48 is connected to a motor 46, which is an induction motor fixed to the outer bottom of the water tank 44, via a belt 49, and the rotation of the motor 46 is transmitted by the belt 49. The rotation of the motor 46 is realized by shifting the voltage phase of the main winding and the auxiliary winding by π / 2 by the phase advance capacitor 52.

The washing machine detects a zero cross of the AC power supply, a control means 47 that controls a series of processes such as washing, rinsing, dehydration, and drying and a rotation of the motor 46, a rotation detecting means 50 that detects the number of rotations of the motor 46, and the like. A zero-cross detection means 51 is provided in the control unit 53.

  As the rotation detecting means 50 for detecting the rotation speed of the motor 46, a method of detecting the rotation speed of the motor 46 by measuring a voltage waveform discharged from the phase advance capacitor 52 from when the motor is turned off, or a rotating body of the motor 46. There is a method of attaching a magnet to the motor and detecting the rotational speed of the motor 46 from the output of the Hall sensor.

  About the washing machine comprised as mentioned above, the operation | movement and an effect | action are demonstrated. The basic operation of the washing machine in a series of steps such as washing, rinsing, dehydration, and drying is the same as that of a well-known general washing machine, and thus the description thereof will be omitted. This control will be described below.

  When the motor 46 is a phase advance capacitor drive type, if the motor 46 is fully energized during the dehydration process, the rotation speed of the motor 46 varies depending on whether the power frequency is 50 Hz or 60 Hz, and a stable dehydration rate or dehydration efficiency is achieved. Cannot be obtained. For this reason, it is general to mix the motor full energization section for increasing the rotational speed and the motor control section for decreasing the rotational speed at an arbitrary ratio, and control at a stable rotational speed.

  In the washing machine according to the present invention, the energization of the motor 46 is turned on / off so that the output of the motor 46 is reduced by an arbitrary value with respect to the full energization at the time of the motor control for decreasing the rotational speed. More specifically, the on / off timing of energization of the motor 46 is detected by detecting the zero crossing time point of the power source by the zero cross detecting means 51, and as shown in FIG. Determine and execute on / off.

  By this control method, generation of electromagnetic noise from the motor 46 is suppressed, and generation of noise when the washing machine is dehydrated can be suppressed.

  As described above, the washing machine according to the present invention can suppress the electromagnetic noise generated from the motor during the dehydration process of the washing machine. It is useful as a modification.

DESCRIPTION OF SYMBOLS 41 Case 42 Rotating tank 43 Elastic support mechanism 44 Water tank 45 Rotating shaft 46 Motor 47 Control means 48 Driven pulley 49 Belt 50 Rotation detection means 51 Zero cross detection means 52 Advancing capacitor 53 Control unit

Claims (1)

A housing, a rotating tub into which laundry is put, a water tub that accommodates the rotating tub and is supported by an elastic support mechanism from the housing, and the rotating tub is fixed at one end and is rotatably fixed to the water tub. Fixed to the other end of the rotating shaft, a motor fixed to the outer bottom of the water tank, a series of steps such as cleaning, rinsing, dehydrating, and drying, and a control means for controlling the rotation of the motor A driven pulley, a belt for transmitting the rotation of the motor to the driven pulley, a rotation detecting means for detecting the rotational speed of the motor, and a zero cross detecting means for detecting a zero cross of an AC power source, Depending on the number of rotations of the motor obtained by the rotation detection means, energization of the motor is turned on / off at the time of the zero cross of the AC power source obtained from the zero cross detection means during the dehydration process. Washing machine features.