JPH0497777A - Electric washing machine - Google Patents

Abstract

PURPOSE:To reduce vibrations in dehydration by preventing the rotational frequency of a combined washing and dehydrating tank from entering a region of the number of natural vibration in an intermittent dehydrating stroke irrespective of the amount of a cloth load. CONSTITUTION:A cloth load amount is detected by a cloth load amount detecting means 8 to determine an ON time of supplying current and OFF time of stopping current for a motor 5 and the repeating number of times of current supply ON-OFF corresponding to the cloth load amount in an intermittent dehydrating stroke. Then the ON time for the motor 5 is shortened compared with the conventional one or the number n1 of times of repetition is reduced to prevent the rotational frequency of a washing-and-dehydrating tank 2 from entering a region of the number of natural vibration. On the other hand, in the case of a large cloth loading amount, the ON time is elongated longer then the conventional one or the number of times of the repetition is increased to set the rotational frequency of the washing-and-dehydrating tank 2 to a high speed rotation not to enter the region of the number of natural vibration in the intermittent dehydrating stroke.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electric washing machine having a dehydration process including an intermittent dehydration process in which a washing and dehydration tank is driven intermittently.

BACKGROUND OF THE INVENTION In recent years, electric washing machines having an intermittent spin cycle in which a washing and spin-drying tank is driven intermittently have been required to reduce vibrations during spin-drying.

Conventionally, this type of electric washing machine has a so-called intermittent spin cycle in which the motor is repeatedly turned ON and OFF during spin-drying.
The number of F repetitions was always constant.

Also, when comparing the dehydration process after washing and the dehydration process after rinsing, the dehydration process after washing requires less electricity to the motor.
There are also electric washing machines that have a longer FF time and a greater number of energization ON--OFF cycles.

This is for the purpose of discharging detergent foam after washing, but is not intended to reduce vibrations during spin-drying.

Problems to be Solved by the Invention In such conventional electric washing machines, during the intermittent dehydration process, the energization ON/OFF time of the motor and the energization ON/O
Since the number of FF repetitions is always constant, the fourth
As shown in the figure, when the amount of cloth load is small (G), it is generally 480 to 6-00 rotations (8 to 6-00 rotations), which is the natural frequency of the machine body.
10 yen) during the intermittent dewatering process, and the rotational speed of the washing/dehydrating tub repeatedly enters and exits the natural frequency range during the time S1 until the main dehydration process begins. Further, since the vibration of the aircraft body becomes large in the natural frequency region, the vibration worsens during the time S1. In addition, when the amount of fabric load is large (Kope does not reach the natural frequency range of the machine body during the intermittent spin cycle, but the rotation speed of the washing/spin tank during the intermittent spin cycle is low, so the fabric is almost completely dehydrated. The main spin-drying process is started in a state in which the washing and spin-drying tank is not in a state where the rotational speed increases during the main spin-drying process. However, there was a problem in that the vibration worsened during the time S2.

The present invention solves the above-mentioned problem, and aims to reduce the vibration during spin-drying by preventing the rotational speed of the washing/spin-drying tub from entering or exiting the natural frequency range regardless of the amount of fabric load during the intermittent spin-drying process. The purpose is

Means for Solving the Problems In order to achieve the above object, the present invention controls a washing and dehydrating tank, a motor that drives a pulsator disposed at the inner bottom of the washing and dehydrating tank, and an energization control to the motor mentioned above. and a cloth load amount detection means for detecting the amount of cloth loaded into the washing and dehydration tank, and the control means is configured to control the amount of cloth during the intermittent dewatering process in which the motor is repeatedly energized ON and OFF. Depending on the amount of cloth load detected by the load amount detection means, the ON/OFF time of energization to the motor and the ON/OFF time of energization are determined so that the rotation speed of the washing/dehydrating tub does not exceed the natural frequency of the machine body.
The solution to this problem is to control the number of OFF repetitions.

Effects The present invention uses the above-mentioned problem-solving means, so that even when the amount of fabric load is small and even when the amount of fabric load is large, the rotational speed of the washing and dehydration tank can be maintained at 1 without going in and out of the natural frequency region. However, in this dehydration process, the speed of increase in the rotational speed of the washing and dehydration tank increases, which shortens the time that the rotational speed of the washing and dehydration tank remains in the natural frequency range, and minimizes the time during which vibration worsens. can. Therefore, low vibration during dehydration can be achieved.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIG.

As shown in the figure, a washing/dehydration tank 2 is rotatably disposed inside an outer tank 1, and a pulsator 3 is rotatably disposed at its inner bottom.
is electrically switched by the mechanical case 4, and the motor 5
rotational force is transmitted. The control device 6 is equipped with a control means 7 configured with a microcomputer or the like to control the energization of the motor 5, and a cloth load amount detection means 8 for detecting the amount of cloth loaded into the washing and dewatering tank 2. . During washing, this cloth load amount detection means 8 energizes the motor 5 for a predetermined period of time by the control means 7, and calculates the cloth load amount based on the attenuation rate of a parameter correlated to the rotation speed of the motor 5 during the subsequent OFF period. For example, when the cloth load is large, the rotation speed of the motor 5 rapidly decreases, and the voltage of the phase advance capacitor of the motor 5 also decreases, so it is necessary to detect changes in the voltage of this phase advance capacitor. The amount of cloth load can be detected.

In the above configuration, FIGS. 2 and 3 (a), (b)
) to explain the operation.

In steps 11 and 12, the fabric load detection means 8 detects the fabric load, and if the fabric load is small, the fabric is washed in step 13 with a water flow and washing time that match the fabric load, and in step 14, the fabric is drained. In step 15, the motor 5 is energized for 08 hours t1 in the intermittent dehydration process according to the cloth load amount.
and OFF time t2 are determined, and the power is turned on in step 16.
-Determine the number of OFF repetitions n1. In step 17, the intermittent dehydration process begins, and in step 18, initial settings are made by the calculation unit built in the control means A (n=○, n: ON of the motor 5).
- OFF repetition times), in step 19, the motor 5 is turned on for a time t1 to drive the washing and dehydrating tank 2,
In step 20, the motor 5 is turned off for a time t2 to stop driving the washing and dehydrating tank 2. ○N-0FF in step 21
ON--OFF is repeated until the number of repetitions n1 is reached. Here, if the ON time t1 of the motor 5 is made shorter than the conventional example according to the fabric load as shown by the dashed line in FIG. 3(a), the number of repetitions n1 is shown by the dotted line.
○N time t1OF of motor 5
By determining the F time t2 or the number of repetitions n1 in combination according to the amount of cloth load, it is possible to prevent the rotational speed of the washing and dehydrating tub 2 from entering or exiting the natural frequency region. next,
In step 22, the main dewatering process is started, and the time (xl, x2) during which the rotational speed of the washing and dehydrating tub 2 is in the natural frequency region can be shortened. That is, xl, x2〈Sl
Can be done. Note that the solid line in FIG. 3(a) shows the characteristics of the conventional example.

Next, if the fabric load amount detected by the fabric load amount detection means 8 in step 11.12 is large, step 2
In step 3, the cloth is washed at a water flow and washing time that matches the amount of cloth loaded, and in step 24, the cloth is drained. In step 25, one JON time t is applied to the motor 5 in the intermittent dewatering process according to the cloth load amount.
3 and the OFF time t4 are determined, and in step 26 the energization is turned on.
Determine the number of N-OFF repetitions n2. Step 27
The intermittent dewatering process starts at step 28, and the initial setting (n=o, n:
After repeating N-OFF (number of times), in step 29, the motor 5 is turned on for a time t3 to drive the washing and dewatering tank 2.
In step 3o, the motor 5 is turned on for a time t4OFFI to stop driving the washing and dewatering tank 2. ON-O in step 31
F ON-OFF is repeated until the number of repetitions reaches n2. Here, if the ON time t3 of the motor 5 is made longer than in the conventional example in accordance with the fabric load, as shown by the dashed line in FIG. 3(b), the repetition power n2 is increased as shown by the dotted line. In some cases, by determining the Oi'J time t3, OFF time t4, or number of repetitions n2 of the motor 5 in combination according to the amount of cloth load, the rotation speed of the washing and dehydration tank 2 can be adjusted to the natural frequency range in the intermittent dehydration process. You can set the rotation to high enough that it won't go into overdrive.

Next, when moving to the main dehydration process in step 32, since the dehydration rate is higher than before, the load applied to the motor 15 becomes smaller and the rotation speed of the washing/dehydration tub 2 increases. That is, the time period during which the rotational speed of the washing and dehydrating tub 2 exists in the natural frequency region (Yl).

Y2) is shortened (Yl, Y2<32), and the time during which vibration deteriorates can be minimized. In addition, Fig. 3 (b
) indicates the characteristics of the conventional example.

Therefore, even when the amount of fabric load is small,
Even when the amount of cloth loaded is large, the rotation speed of the washing/dehydration tank 2 does not enter or leave the natural frequency range of the machine, and the speed of increase in the rotation speed of the washing/dehydration tank 2 is high in the main dehydration process. Since the time during which the rotational speed of the dehydration tank 2 exists in the natural frequency range is short, the time during which vibration deteriorates can be minimized. Therefore, low vibration during dehydration can be achieved.

Furthermore, in the above embodiments, the cases where the cloth load amount is small and large are described, but low vibration can be similarly achieved with other cloth load amounts.

Effects of the Invention As is clear from the above embodiments, according to the present invention, in the intermittent spin-drying process, the control means adjusts the rotation speed of the washing/spin-drying tub according to the fabric load detected by the fabric load detection means. Energize the motor so that it does not exceed the natural frequency of the machine.
Since the N-OFF time and the number of energization ON-OFF repetitions are controlled, even when the amount of fabric loaded is small or when the amount of fabric loaded is large, the rotation speed of the washing and dehydrating tank is kept close to the natural frequency of the machine. The speed of increase in the rotation speed of the washing and dehydration tank can be increased during the main spin-drying process without going in and out of the area, which shortens the time that the rotation speed of the washing and spin-drying tank exists in the natural frequency area, minimizing the time during which vibration worsens. can do. Therefore, low vibration during dehydration can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electric washing machine according to an embodiment of the present invention.
Figure 2 is a flowchart of the main parts of the electric washing machine, Figure 3 (a
) and (b) are characteristic diagrams of the spin-drying time and rotational speed of the same electric washing machine when the amount of cloth loaded is small and when the amount of cloth loaded is large, respectively. It is a characteristic diagram of rotation speed. 2...Washing/dehydration tank, 3...Pulsator,
5... Motor, 7... Control means, 8... Fabric load amount detection means.

Claims (1)

[Claims] A washing and dehydration tank, a motor for driving a pulsator disposed at the inner bottom of the washing and dehydration tank, a control means for controlling energization of the motor, and a detection of the amount of cloth loaded into the washing and dehydration tank. The control means controls the washing and dewatering tub according to the fabric load detected by the fabric load detection means during an intermittent dewatering process in which the motor is repeatedly turned ON and OFF. An electric washing machine in which the ON/OFF time of energization to the motor and the number of times of ON/OFF repetition of energization are controlled so that the rotational speed does not exceed the natural frequency of the machine body.