JPH03222992A - Washing machine - Google Patents

Abstract

PURPOSE:To prevent fabric from being damaged and shrunk without a reduction in washing effect even if laundry are of special fabric such as wool, silk or the like, by a method wherein the operation of a motor is controlled so that the rotation is kept in one-direction and the rotational speed is increased and decreased with time in a curved waveform at regular periods. CONSTITUTION:As a motor 5 is cycled in one-direction, an agitator 4 is also rotated in one-direction, resulting in prevention of fabric shrinkage. As the rotational speed of the motor 5 is increased and decreased in a curved waveform, the agitator is similarly revolved. The velocity of the water current in a rotary drum 3 is increased with the increase in the rotational speed of the agitator 4, and the decrease in the rotational speed of the agitator 4 causes a braking action against the water current, so that the water current is prevented from being transformed into eddy currents. As a result, the laundry is well fluidized up and down, preventing the laundry from sinking down without an increase in contacting frequency of the laundry to the agitator 4 and with less damage on the fabric. A relative speed difference between the laundry and the water current is produced so that the washing effect is not reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a washing machine with an improved motor drive control structure.

(Prior Art) Conventionally, in a washing machine, a stirring body provided inside a tub is rotated by a motor to form a water flow inside the tub, thereby washing and rinsing. In this case, the motor is rotated in forward and reverse directions as shown in Figure 7, thereby causing the agitator to rotate in forward and reverse directions.
Furthermore, the motor is driven at a constant rotational speed in both forward and reverse rotations.

(Problem to be Solved by the Invention) However, in the above-mentioned conventional device, the agitator, that is, the motor, is rotated in forward and reverse directions, so if this is repeated, the laundry will become twisted, and after washing, wool, silk, etc. Shrinkage sometimes occurred in laundry made of Note that one possible solution to this problem is to rotate the motor in one direction at a predetermined speed, but in this case, since the rotation speed of the motor is constant, the water flow becomes a vortex, causing the laundry to sink. The frequency of contact with the agitator becomes very high, which may cause fabric damage to the laundry, and the laundry and the water flow move with no relative speed difference, resulting in a decrease in cleaning performance.

Therefore, it is an object of the present invention to provide a washing machine that does not cause shrinkage even when the laundry is made of special fabrics such as wool or silk, does not cause fabric damage, and does not reduce cleaning performance. is to provide.

[Structure of the Invention] (Means for Solving the Problems) The present invention rotates a stirring body with a motor to wash and
In the apparatus for rinsing, a motor control means is provided for driving and controlling the motor so that the rotation direction of the motor is unidirectional and the rotational speed increases and decreases approximately in a curved wave shape at a predetermined period as time passes. It has some characteristics.

(Operation) According to the above means, since the motor is rotationally driven in one direction, the stirring body is also rotationally driven in one direction.

With this, the cloth will not be damaged as would occur when the cloth is rotated in forward and reverse directions. Further, as the motor rotational speed increases and decreases in a curved manner, the stirring body is similarly driven to rotate.

At this time, the flow rate of water in the tank also increases due to the increase in rotation speed. However, when the rotational speed of the agitator decreases, the flow of water is braked, so that the water flow does not become a vortex. As a result, the laundry can flow well in the vertical direction and will not sink. Also, a relative speed difference occurs between the laundry and the water flow.

(Embodiment) A first embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

First, FIG. 2 shows a dehydrating and washing machine.

A water receiving tank 2 is provided within the outer box 1, and a rotating tank 3 is provided within this water receiving tank 2. A container-shaped stirring body 4 is arranged inside the rotating tank 3. A motor 5 consisting of a brushless motor is disposed at the outer bottom of the water receiving tank, and a mechanism section 6 including a speed reduction mechanism and the like is disposed. This mechanism section 6 decelerates the rotation of the motor 5 and transmits it to the stirring body 4 during washing operation, and transmits it to the rotating tank 3 during dehydration.
and is transmitted to the stirring body 4. A drain valve 7 is provided in the drainage channel from the water tank 2, and an air trap 8 is formed at the bottom of the water tank 2. A water level sensor 10 is connected.

This water level sensor 10 is connected to the upper cover'-12 together with the water supply valve 11.
An operating section 13 is arranged at the front part of the upper cover 12.

Next, FIG. 1 shows the electrical configuration, and the operation control circuit 14 includes a microcomputer. A switch input from the switch 15 and a water level detection signal from the water level sensor 10 are provided.

Furthermore, this operation control circuit 14 constitutes a part of a motor control circuit 16 as a motor control means, and other components of this motor control circuit 16 will be explained.

When the PWM signal generation circuit 17 is given the voltage command signal Sd from the operation control circuit 14, it generates a pulse Pa (with a period of 0.
A predetermined constant value of 1 to 066 msec) is generated and provided to the combining section 18. In this case, the duty ratio is ton/(ton+to
l'f'). Timing signal generation circuit 1
Reference numeral 9 generates a timing signal Sb (three phases) for timing the energization of the stator winding of the motor 5 based on the position detection signal from the position detection element 20;
The timing signal sb is given to the combining section 18. The synthesis unit 18 generates an energization pattern signal Sr(
3-phase) and supplies it to the motor voltage circuit 21. The motor voltage circuit 21 applies a DC voltage Vo (100V) given from the DC power supply circuit 22 to the motor 5 in a pattern based on the energization pattern signal Sr. As shown in the figure, the applied voltage E in this case is shaped by the duty ratio by the PWM signal generation circuit 17 and the timing by the timing signal generation circuit 19, and is shaped into the timing by the timing signal generation circuit 19. The applied voltage Vx of No. 5 is changed in magnitude. In other words, the voltage ratio V x /V o is the above P
The duty ratio t on/(
t on + t off ).

The operation control circuit 14 is configured to rotate the motor 5 in one direction, and also changes the level of the voltage command signal Sd sequentially at a predetermined period into a waveform, in this case a sine curve. As a result, the equivalent applied voltage Vx changes in a sine curve shape. Therefore, as shown in FIG. 3, the motor 5 is controlled so that its rotational speed increases and decreases approximately in a sine-cube shape at a predetermined period (6.4 seconds in this embodiment) as time passes. In this embodiment, the maximum rotational speed Nh according to the load capacity (amount of laundry) is within the rotational speed region indicated by diagonal lines in FIG.
and a minimum rotational speed Ng. For example, if the load capacity is 5 kg, if the above-mentioned duty ratio is set at two points, large and small, along the load capacity characteristic line R5, the maximum rotational speed Nh is determined by the large duty ratio, The minimum rotational speed Ng is determined at a small duty ratio. Moreover, in FIG. 5, the setting range of the maximum rotation speed and minimum rotation speed of the agitator 4, which is suitable when the laundry is of a special kind such as wool or silk, is shown by the shaded area, and the maximum rotation speed is shown. and the minimum rotation speed are both set low.

According to this embodiment, since the motor 5 is rotationally driven in one direction, the stirring body 4 is also rotationally driven in one direction. With this, even if the laundry is of a special type such as wool or silk, the cloth does not shrink as in the conventional method in which the agitator is rotated in forward and reverse directions. Further, as the motor rotational speed increases and decreases in a curved manner, the stirring body 4 is similarly driven to rotate. At this time, due to the increase in the rotational speed of the agitator 4, the flow rate of water in the rotating tank 3 increases. However, when the rotational speed of the agitator 4 decreases, the flow of water is braked, so the flow of water does not become easier.

As a result, the laundry can flow well in the vertical direction and will not sink, and therefore the frequency of contact between the laundry and the agitator 4 will not increase, and there is no risk of fabric damage. There is no. Furthermore, since a relative velocity difference occurs between the laundry and the water flow, the cleaning performance does not deteriorate.

In the above embodiment, the change in the rotational speed of the motor 5 is set in a sine curve shape, but this changes intermittently in a wave-like manner as shown in FIG. In short, the rotational speed of the motor may be set to increase or decrease in a substantially wave-like manner at a predetermined period as time passes.

[Effects of the Invention] As is clear from the above description, the present invention is characterized in that washing and rinsing are carried out by rotationally driving an agitator by a motor, and in which the motor is rotated in one direction. In addition, it is characterized by being equipped with a motor control means for controlling the drive so that the rotational speed increases and decreases in a substantially wave-like manner at a predetermined period with the passage of time. Even in the case of cloth, it does not shrink, has no fear of cloth damage, and has excellent effects such as no reduction in cleaning performance.

[Brief explanation of drawings]

1 to 5 show a first embodiment of the present invention, FIG. 1 is a block diagram showing the electrical configuration, FIG. 2 is a vertical side view of the washing machine, and FIG. 3 is the rotational speed of the motor. FIG. 4 is a diagram showing the relationship between duty ratio, rotational speed, and load capacity, and FIG. 5 is a diagram showing the setting range of rotational speed when the laundry is a special type of fabric. Figure 6 shows the second embodiment of the present invention.
FIG. 3 is a diagram corresponding to FIG. 3 showing an embodiment of the present invention. FIG. 7 is a diagram corresponding to FIG. 3 showing a conventional example. In the figure, 3 is a rotating tank, 4 is an agitator, 14 is an operation control circuit,
16 is a motor control circuit (motor control means).

Claims (1)

[Claims] 1. In a device in which washing and rinsing are performed by rotationally driving an agitator by a motor, the rotation direction of the motor is unidirectional, and the rotation speed increases and decreases approximately in a wave-like manner at a predetermined period as time passes. A washing machine characterized in that it is provided with a motor control means for driving and controlling the washing machine so as to perform drive control.