JPH057688A - Controller for washing machine - Google Patents

Abstract

PURPOSE:To always judge the correct quantity of cloth by estimating V belt tension while revloving stirring fans in a short time just after a dehydrating process is completed, and judging the quantity of cloth based on a correspondent cloth quantity judgement table. CONSTITUTION:In the state of sticking laundry to a dehydrating vessel 2 just after the end of the dehydrating process and not putting the laundry on stirring fans 3, the stirring fans 3 are revolved in a short time and among output signals from a revolution detector 11 at such a time, the data of inertia revolution are stored in a storage part 12a. The storage part 12a always stores the data prescribed plural times. Next, a data processing part 12b selects the data having the most number of inertia revolutions and based on these data, a revolution resistance estimation part 12c estimates the V belt tension. Afterwards, a cloth quantity judgement table selection part 12d selects the table corresponding to the estimated V belt tension. In the case of judging the quantity of cloth in washing to be executed later, a cloth quantity judgement part 12e judges the quantity of cloth by allocating the signal from the revolution detector 11 to this table.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the accuracy of a laundry amount determination device for a washing machine.

[0002]

2. Description of the Related Art In recent years, washing machines have been automated to judge the amount of laundry put in a washing tub and automatically set the optimum water level and the washing time based on the amount of laundry. I'm out.

As a method of detecting the cloth amount, for example, as disclosed in Japanese Patent Laid-Open No. 62-176491, the stirring blade is intermittently rotated for a predetermined time, and the rotation speed of the stirring blade at this time is detected to determine the cloth amount. A method of controlling a washing machine to make a determination has been proposed.

In this system, the rotation speed of the stirring blade is influenced by the amount of cloth, the driving force of the driving means,
It is also affected by the resistance to the rotation of the drive means. If the driving force of the driving means or the resistance to rotation fluctuates or changes over time, the amount directly becomes an error in the cloth amount determination.

[0005]

As described above, variations in the drive system and changes with time increase the error in the cloth amount determination. In particular, the tension force of the V-belt that transmits the power from the motor to the driving means of the stirring blade decreases with use, and this change has a great influence on the above-described cloth amount detection method. Conventionally, a washing machine is used sufficiently, and the judgment level of the amount of cloth is determined based on the point that the V-belt tension is reduced and it is almost stable. For this reason, the product immediately after being produced has a large tension on the V-belt, so that there is a problem that the amount of cloth is judged more than it actually is.

The present invention detects the V-belt tension force and corrects the cloth amount judgment level according to the V-belt tension so that the correct cloth amount can be judged at any time.

[0007]

In order to achieve the above-mentioned object, the present invention has a rotation speed detecting means for detecting the rotation speed of a stirring blade drive system, and a storage means for storing an output signal of the rotation speed detecting means, Included is a cloth amount judging means for judging the amount of laundry based on the output signal of the rotation speed detecting means, and the stirring blade is driven for a short time immediately after the completion of the dewatering step (intermediate dewatering may be performed). The output signal of the rotation detection means at that time is stored in the storage means for a plurality of times from the latest, and the V-belt tension force is estimated from the data with the lightest load (the one with the highest rotation speed) in the storage, and The problem solving means is to shift the cloth amount determination level according to the V-belt tension force.

[0008]

The present invention focuses on the state where the laundry is stuck to the dehydration tub immediately after the dehydration process and the laundry is not placed on the stirring blade. When the stirring blade is driven for a short time in this state, the rotation speed detection at that time is detected. There is a certain correlation between the output signal of the means and the V-belt tension force. By utilizing this, the V-belt tension force is estimated, and the cloth amount determination level is shifted according to the estimated V-belt tension force. , So that the correct amount of cloth can be determined at all times.

However, immediately after dehydration, the situation in which the laundry is stuck to the dehydration tank and does not rest on the stirring blade does not always occur. When the amount of cloth is large, there are many cases where laundry is placed on the stirring blades in most cases, and even when the amount of cloth is small, it may be placed depending on the type of cloth, but in general washing behavior,
Once every 10 to 30 times, it can be expected that there is no laundry on the stirring blade, so this is utilized.

The output of the rotation speed detecting means is greatest when the laundry is not placed on the stirring blade, and is small when the laundry is placed. Therefore, if you select the data with the largest number of rotation detection from the latest multiple times (30 times or more), you can regard it as the data with no laundry on the stirring blade,
From this, the V-belt tension can be estimated. In addition, the data of multiple times is always updated by discarding the oldest data when new data comes in, so that the change in V-belt tension with time can be grasped.

By estimating the V-belt tension force as described above and shifting the cloth amount determination level based on the estimated force,
You can always judge the correct amount of cloth.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, an outer tub 1 is provided with a washing / dehydrating tub 2 rotatably inside, and an agitating blade 3 is provided in an inner lower portion of the washing / dehydrating tub 2. The mechanical device 4 is composed of a speed reducer for controlling the rotation of the washing / dehydrating tank 2 and the stirring blade 3, a one-way clutch, a brake, and the like. The induction motor 5 is two-phase driven by the bidirectional thyristors 6 and 7 and the phase advancing capacitor 8, and transmits the rotation to the mechanical device 4 by the V belt 9 and the impeller pulley 10. The rotation detection device 11 detects the number of rotations of the impeller pulley 10, and is composed of a ring-shaped multi-pole permanent magnet and a Hall IC. The control device 12 controls the functions of the entire washing machine, and includes therein a storage unit 12a that stores the output signal of the rotation detection device 11, a data processing unit 12b that processes data in the storage unit 12a, and a data processing unit 12b. The rotation resistance estimation unit 12c that estimates the tension of the V-belt based on the result of 1 and the cloth amount determination table selection unit 1 that selects the table used for the amount of cloth determination from the V-belt tension force.
2d, the selected table and the output signal of the rotation detection device 11 are compared to determine the cloth amount.
And a motor control unit 12f for controlling the motor. The motor drive unit 13 is the motor control unit 12
ON / OFF of bidirectional thyristors 6 and 7
Take action. Immediately after the laundry 14 is dehydrated, the washing and dewatering tank 2
Clings to the wall of.

FIG. 2A shows a method of driving the motor during short-time driving immediately after dehydration. That is, 0.3 seconds for right rotation, 0.3 seconds for OFF (pause), 0.3 seconds for left rotation,
OFF 0.3 seconds is repeated multiple times. (B) is the output (rotation speed) of the rotation detection device 11 at that time. The ON period is a rotation period due to motor drive, and the OFF period is a rotation period due to inertia. The total number of rotations during this inertial rotation period is
The correlation with the V-belt tension is large.

The correction operation of the cloth amount determination in the above configuration will be described. First, immediately after the washing machine is operated to complete the dehydration process, the laundry 14 is stuck to the wall surface of the washing / dehydrating tub 2 and is barely placed on the stirring blade 3. In this state, FIG.
2 is given to the motor drive unit 13, the motor drive unit 13 turns on the bidirectional thyristor 6, and
The motor 5 is rotated clockwise as shown in FIG. The rotation of the motor 5 is transmitted to the stirring blade 3 via the V-belt 9 and the impeller pulley 10 mechanical device 4. Next, when the bidirectional thyristor 6 is turned off and the electric power of the motor 5 is cut off, the stirring blade rotates due to inertia as shown in the OFF period of FIG. The damping method is determined by the resistance to the rotation of the rotating system such as the V-belt 9 and the mechanical device 4 because the stirring blade is not loaded. The resistance to this rotation is largely influenced by the tension of the V belt 9. Therefore, the tension of the V-belt can be estimated by knowing the inertial rotation speed. This inertial rotation speed is the rotation detection device 11
The tension force of the V-belt can be easily estimated because it can be known by. The stirring blade is rotated not only on the right side but also on the bidirectional thyristor 7 to rotate to the left side, and is inverted a plurality of times in order to improve the detection accuracy.

By the way, the V-belt tension force can be estimated only by knowing the inertial rotation speed, but in reality, as described above, the probability that the laundry is not placed on the stirring blade immediately after the dehydration step is considerably low. In general washing behavior, the laundry does not fall on the stirring blade at a rate of about once every 10 to 30 times. Therefore, it is difficult to estimate the belt tension force with one-time data.

In order to solve this, a storage unit 12a and a data processing unit 12b are provided in the control device 12, and inertial rotation data of the output signal from the rotation detection device 11 is stored in the storage unit 12a. The storage unit 12a stores this data each time immediately after the dehydration step of the washing work, and when the number of storages reaches a predetermined number of times (example 30 times), discards the oldest data each time new data comes in. The data is always retained a predetermined number of times. Next, the data of the predetermined plurality of times is sent to the data processing unit 12c, and the data having the largest inertial rotation speed is selected from the data. Rotational resistance estimation unit 12c based on the selected data
Then, the V-belt tension force is estimated from the table obtained experimentally.

By the way, the amount of cloth is determined by reversing the stirring blade for a short time at the very beginning of the washing operation, and the amount of cloth is determined by the rotational speed of inertia at that time. The relationship between the rotational speed of inertia and the amount of cloth is , V-belt tension varies. Therefore, in order to correctly determine the cloth amount even when the V-belt tension changes,
It suffices to prepare a table for determining the number of revolutions of inertia and the amount of cloth for each V-belt tension force and use a table according to the V-belt tension force.

In the present embodiment, the rotation resistance estimation unit 12 described above is used.
Based on the V-belt tension force estimated in c, the cloth amount determination table selection unit 12d determines the V-belt tension force from the table for determining the inertial rotation speed and the cloth amount prepared for each V-belt tension force described above. Select the table that has
Send to 2e. The cloth amount determination unit 12e determines the cloth amount by applying a signal from the rotation detection device 11 to this table at the time of determining the cloth amount in the subsequent washing operation. Ie V
Since the amount of cloth is determined using the table corrected by the belt tension, the amount of cloth can be correctly determined even if the V belt tension changes with time.

In order to make the explanation easy to understand, the cloth amount detection with respect to the change in the tension force of the V-belt has been described. However, the present invention can correct not only the change in the tension force of the V-belt but also the drive system. It is possible to compensate for all changes in resistance to rotation.

[0021]

As described above, according to the present invention, the V-belt tension force is estimated by rotating the stirring blade for a short period of time immediately after the completion of the dehydration step while the laundry is not placed on the stirring blade. From the cloth amount judgment table provided for each tension force, V
By determining the cloth amount based on the table corresponding to the belt tension force, it is possible to always perform the correct cloth amount determination even if the V belt tension force changes with time.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2A is an explanatory diagram of a motor driving method according to an embodiment of the present invention. FIG. 2B is an explanatory diagram of a motor rotation speed according to the embodiment of the present invention.

[Explanation of symbols]

 1 Outer Tank 2 Washing / Dehydrating Tank 3 Stirring Blade 4 Mechanical Device 5 Motor 9 V Belt 10 Impeller Pulley 11 Rotation Detecting Device 12 Control Device

Claims (1)

Claim: What is claimed is: 1. A stirring impeller rotatably disposed at the bottom of a washing / dehydrating tub, a driving means for the stirring impeller, a rotation detecting means for detecting the number of revolutions of the driving means, and a rotation detecting means. In a washing machine equipped with a storage unit for storing the output signal of, and a cloth amount determination unit for determining the amount of laundry by the output signal of the rotation detection unit, immediately after the dehydration process, the stirring blade is driven for a short time, The output signal of the rotation detection means at that time is stored in the storage means for a plurality of times from the latest one, and the determination result of the cloth amount determination means is corrected based on the data with the lightest load among the stored data. A control device for a washing machine.