JPS63318995A - Load quantity detector of washing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a load amount detection device for a washing machine that detects the amount of clothes, etc. placed in a washing tub or a washing and dehydrating tub.

2. Description of the Related Art Many load amount detection devices for washing machines that detect load amount have been provided. For example, Special Public Interest Publication No. 61-22598
There is a load amount detection device shown in the publication. As shown in FIG. 6, this load amount detection device connects the washing motor 2, which selectively drives the stirring blades and the washing tub/dehydration tub, to the AC power source 1 via switching means 4a, 4bQ, and further connects the washing motor 2 to A capacitor 3 is connected between the windings. The switching means 4h, 4b are connected to the gate G1 from the control circuit.
．． A signal is sent to G2, and it turns on and off based on that signal. In addition, a current transformer 6 is connected to the motor 2, and the output of this current transformer 6 is transmitted to a control circuit 5.
It is now entered into And the control circuit 5 is
Switching means 4&.

The washing motor 2 is started under 4bi control, the current value of the washing motor 2 is detected after a certain period of time, and the load amount is determined based on the current value.

Problems to be Solved by the Invention However, in the conventional configuration, the current value of the motor 2 is affected by variations in motor characteristics or voltage fluctuations of the AC power supply 1, so there is a problem in that the variation in load amount detection becomes severe. It had In addition, in the conventional load amount detection method, the amount of load applied to the stirring blade varies depending on the height of the water level, so there was a problem that the load and amount of cloth put into the tank could not be detected with high accuracy.

In view of the above problems, it is an object of the present invention to detect the amount of load with high accuracy.

Means for Solving the Problems In order to achieve the above object, the present invention provides a control means for controlling energization of a motor that drives a stirring blade, a water level detection means for detecting a water level in a tank, and the control means. load amount detection means for energizing the motor for a predetermined time and detecting the load amount based on the attenuation rate of a parameter correlated to the rotational speed of the motor within the subsequent off period; Water is supplied to an appropriate water level according to the load amount detection, and the fabric load amount detection is performed again at the appropriate water level,
The configuration is such that the final load amount is determined based on that value.

Effect According to the above configuration, the load amount is determined based on a parameter that has a correlation with the load amount, such as the damping rate of the motor, for example, the damping time, and the water level is set to an appropriate water level based on the determination result. Since the load amount is detected again, the load amount can be detected with high accuracy.

EXAMPLES Examples of the present invention will be described below with reference to FIGS. 1 to 5.

As shown in FIG. 3, the configuration of the fully automatic washing machine in this embodiment is as shown in FIG.
has stirring blades 12 rotatably disposed at its inner bottom.

The stirring blade 12 and the washing and dehydrating tank 10 are connected to the mechanical case 13.
is selectively switched, and the rotational force of the motor 2 is transmitted.

Next, the control section of the fully automatic washing machine will be explained with reference to FIG. That is, a capacitor 3 is connected between the main coil and the auxiliary coil of a motor 2 connected to an AC power source 1, and a bidirectional three-terminal thyristor (one of the switching devices) is connected between the terminals of the capacitor 3 and the AC power source 1. (hereinafter referred to as TRIAC) 4a.

4b is connected. When the triac 4a becomes conductive, the motor 2 rotates forward, and the triac 4a! Motor 2, which turns off L and turns on triac 4bf, reverses. The five control circuits receive instructions from the operation keys.

Lid switch 50. A triac 41L drives the motor 2 based on signals from the water level detection device 6B and the like.

4b and drain valve magnet 8. Controls switching of triacs 4c and 4d that drive the water supply valve 7.

The capacitor voltage detection circuit 5C is the capacitor 3 of the motor 2.
It detects the terminal voltage of The terminal voltage of the capacitor 3 is correlated with the motor rotation speed, and the capacitor voltage attenuates in accordance with the rotation speed during the rest period before the triac 4a or 4b is made conductive and the rotation is subsequently reversed.

In Fig. 2, a triac 4a or 4 that drives the motor 2 is shown.
3 shows the change in the terminal voltage of capacitor 3 when b is turned off. In the figure, "man" is a case where the load amount is small and the amount of decrease in the motor rotation speed is small, and "B" is a case where the load amount is large and the motor rotation speed decreases rapidly. During the rest period of the forward and reverse rotation of the motor 2, the triacs 4a and 4b are both off, so the terminal voltage of the capacitor 3 becomes 0. However, since the motor 2 is rotated and the stirring blade is driven before the rest period, The motor 2 continues to rotate due to inertia, and an induced voltage is generated in the main coil and the auxiliary coil.As the number of rotations decreases, the induced voltage decreases, resulting in a waveform as shown in FIG. When the amount of load is large, the motor rotation speed rapidly decreases and the capacitor voltage also decreases, so it is possible to detect the amount of load such as the amount of cloth.

The decay rate of the rotation speed, that is, the decay time of the capacitor voltage (
T11 in FIG. The amount of load is determined by measuring the rate of change of the capacitor voltage, or the attenuation rate of the number of voltage waveforms.

However, as shown in Figure 4, each cloth load 1
The accuracy is different. That is, the ratio y/x of the difference X in the number of waveforms of the capacitor voltage of the cloth load amount and the variation y of the number of capacitor voltage waveforms in each cloth load amount differs depending on the water level at the time of detection. For example, relatively speaking, it is more accurate to perform detection at a low water level when the amount of cloth load is not detected, and it is better to perform detection at a slightly higher water level when the amount of load is large. Therefore, the fabric load is detected in advance at a low water level to determine whether it is a large or small load, then the water level is set to an appropriate level for the amount of fabric, and the fabric load is detected again. If the final cloth load amount is used, the cloth load amount can be detected with higher accuracy.

Next, the procedure for determining the amount of cloth will be explained with reference to FIG.

That is, as shown in FIG. 6 (+a), after setting the water level in the initial setting, water supply is started, and when the set water level is reached, water supply is stopped and stirring is started. And motor 2'i20~
Stirring is performed in forward and reverse directions 30 times, and the number of capacitor voltage waveforms during the period when the motor output is OFF is measured. At this time, the amount of cloth load is determined in two levels: small amount and high amount of electricity, and the water level is set to be appropriate for the amount of load at that time. Next, as shown in FIG. 5(b), the cloth amount detection process is performed again at an appropriate water level to make a final cloth amount determination. In this case, the cloth load amount is determined by comparing the cloth load amount discrimination reference value (the number of capacitor voltage waveforms shown in Figure 4 ■) with the detected capacitor voltage waveform number. As is clear from FIG. 4, since it differs depending on the water level at the time of detection, the fabric load amount discrimination reference value is stored in the control circuit 6A for each detected water level.

In this embodiment, the load amount was determined by detecting the capacitor voltage of the motor, but it may be determined by the number of revolutions per current, and any parameter that correlates with the rotation of the motor may be used.

Effects of the Invention As is clear from the above embodiments, according to the present invention, the motor is driven for a certain period of time and the load amount is determined by measuring the damping rate of the motor immediately after it turns from on to off. It is possible to perform load amount detection with high accuracy without being affected by such factors. Further, since the load amount is detected at a water level suitable for the load amount, the load amount can be determined with stable accuracy no matter what the load amount is.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a cloth amount load detection device and its control circuit for a fully automatic washing machine according to an embodiment of the present invention, and Fig. 2 is a waveform diagram of the capacitor terminal voltage immediately after the motor is driven and turned off. , Figure 3 is a vertical sectional view of the main parts of the fully automatic washing machine.
Fig. 4 is a graph showing the relationship between the number of voltage waveforms and the amount of cloth for each water level, Fig. 5 is a flowchart showing the control for detecting the amount of cloth, and Fig. 6 is a block diagram of a conventional cloth amount load detection device. . 1...AC power supply, 2...motor, 3.
...Capacitor, 42L, 4b...Switching device, 6 people...Control circuit, 5B...
...Water level detection device, 1Q...Washing and dehydration tank,
11... Outer tank. Name of agent: Patent attorney Toshio Nakao and 1 other person10
--191jidarede small l negative／/---Tato 襠 3rd figure 4th figure 5th figure (α) (b) One = N Figure 6

Claims (1)

[Claims] A control means for controlling the energization of the motor that drives the stirring blade; a water level detection means for detecting the water level in the tank; Load amount detection means detects the load amount based on the attenuation rate of the correlated parameter, and the load amount detection means supplies water to an appropriate water level according to the first load amount detection, and then increases the fabric load amount again. A load amount detection device for a washing machine that performs detection at the above-mentioned appropriate water level and determines the final load amount based on the detected value.