JPS61240996A - Apparatus for detecting washing article quantity 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 INDUSTRIAL APPLICATION The present invention relates to a device for automatically detecting the amount of loaded laundry.

Conventional technology A method has been proposed in which the amount of laundry is detected based on changes in current caused by load fluctuations in a motor connected to a pulsator. The weight of the laundry was measured based on the change.

Problems to be Solved by the Invention However, in the conventional technology, the weight of the laundry was detected by the impact of the laundry hitting the pulsator, and therefore the weight could not be accurately detected. The present invention solves these problems and provides a laundry amount detection device for a washing machine that accurately detects the weight of laundry.

Means for Solving the Problems In order to solve the above problems, the present invention provides a motor for rotating a washing tub, a motor drive device for driving this motor,
A control device that controls this motor drive device, a washing tub stop detection device that detects when the washing tub stops rotating, and a signal that stops the motor of the control device to start measuring time, and an output of the washing tub stop detection device. The washing machine is equipped with a time measuring device for finishing the measurement, and the amount of laundry put into the washing tub is determined based on the output of the time measuring device. The amount of laundry in the washing tub is detected by measuring the time that the washing tub continues to rotate due to inertial force after the electricity is turned off.

EXAMPLE An example of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a washing tub, 2 is the laundry put in the washing tub, 3 is a motor that rotates the washing tub 1, 4 is a motor drive device that drives the motor 3, and 6 is a device that controls the motor drive device 4. A control device 6 is a washing tub stop detection device that detects whether the rotation of the washing tub 1 has stopped; 7 is a time measuring device to which the output of the washing tub stop detection device 6 and the motor drive device 4 are connected; The measurement of the running time starts upon receiving a signal to stop the motor 2 of No. 5, and ends upon the output of the washing tub stop detection device 6. And its output is the control device 6
It is connected to the. Reference numeral 8 represents a start switch, and reference numeral 9 represents a pulsator driven by the motor 3.

The operation of the laundry amount detection device for a washing machine configured as described above will be explained below.

First, put the laundry 2 into the washing tub 1 and press the switch 8.

Then, a motor drive signal is output from the control device 6 to the motor drive device 4, and the motor 3 is driven to rotate the entire washing tub 1 and drive the motor until it reaches a constant speed. Then, a signal to stop the motor is sent from the control device 6 to the motor drive device 4.
is output to the time measuring device 7, and the time measuring device 7 starts measuring time from that moment. At the same time, the motor drive device 4 stops energizing the motor 3. However, the washing tub 1 continues to rotate for a certain period of time due to inertia due to its own weight and the weight of the laundry 2 in the tub, and eventually comes to a safe stop. This time is detected by the washing tub stop detection device fault 6, and the signal is input to the time measuring device 7 to stop time measurement. That is, by this operation, the short time measuring device 7 measures the time T during which the washing tub 1 is rotating due to inertia.

The length of this time 1 is determined by the control device 6, the weight of the laundry 2 is determined, water is supplied in an amount corresponding to the weight, and the washing begins.

Next, let us consider theoretically the correlation between the time T and the mass m of the laundry. Now, the inner diameter of washing tub 1 is 2D.

The mass of the washing tub 1 is M, and the mass of the laundry 2 is m.

If the rotational speed of the motor 3 is n (τp, m) and the gravitational constant is 9, then the torque T when the motor rotates at a constant speed.

is given by the following equation).

······four shall be.

This is because both T and TM are functions of the angular velocity W.

This equation (B) is a differential equation. Jin's differential equation shows that if the initial condition is solved as 'rF(w) when t=o, a certain correlation will occur between I and time T. Although the detailed formula is omitted here, the experimental results are shown in FIG. As can be seen from FIG. 2, the mass m of the laundry 2 and the rotation time T due to inertia have a linear function relationship.

FIG. 3 shows a specific embodiment of the washing tub stop detection device 6. As shown in FIG. 10 is a commercial AC power supply, 11 is a motor 3 that is 0N-O.
It is an instantaneous drive device that performs FF control, and in this embodiment, a bidirectional thyristor is used. Its one end is connected to the motor main winding 12 and one end of the phase advance capacitor 14, and the other end of the motor main winding source 12 is connected to one end of the AC power supply 1° along with one end of the auxiliary winding 16, and the motor's auxiliary winding The other end of the line 16 is connected to the other end of the phase advance capacitor 14.

In addition, a motor voltage detection device 13 is installed at both ends of the motor main winding 12.
is connected.

The operation of the washing tub stop detection device configured as described above will be described below.The moment the motor drive signal is turned off, the motor main winding 12 generates a voltage due to a back electromotive force, and the washing tub 1 While the motor continues to rotate, a voltage acting as a generator is generated in the motor main winding 12 (FIG. 4). The motor voltage detection device 13 detects the voltage of this motor main winding 12. Therefore, by providing a constant rotation stop signal level v1 in the motor voltage detection device 13, it is possible to detect the stop of the motor. In this way, the motor drive signal is
Time T from when the FF is turned on until the motor stops.

In other words, the rotation time due to inertia can be detected.

In addition, the washing tub stop detection device 6 can also use means such as a Hall IC, a magnet, and a tachometer generator.

Effects of the Invention As described above, according to the present invention, since the amount of laundry is detected by measuring the rotation time due to the inertia of the washing tub, it is possible to detect the fluctuation of the motor current and calculate the impact force between the laundry and the pulsator. Compared to the visual method, it can automatically detect the accurate weight of laundry.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a device showing an embodiment of the present invention, Fig. 2 is a characteristic diagram of experimental results of the same device, Fig. 3 is a specific circuit diagram of a washing tub stop detection device in the same device, and Fig. 4 The figure shows the motor voltage waveform and motor drive signal waveform in the specific circuit of Figure 3. 0 1... Washing tub, 2... Laundry, 3...
...Motor, 4...Motor drive device, 6.
. . . Control device, 6 . . . Washing tub stop detection device, 7 . . . Time measurement device. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
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Claims (1)

[Claims] A motor for rotating a washing tub, a motor driving device for driving the motor, a control device for controlling the motor driving device, a washing tub stop detection device for detecting rotation stoppage of the washing tub, and a motor for the control device. A time measuring device that starts measuring time in response to a stop signal and ends the measurement based on the output of the washing tub stop detection device, and determines the amount of laundry put into the washing tub based on the output of the time measuring device. A laundry amount detection device for a washing machine, which is characterized by: