JP2762648B2 - Washing machine control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a washing machine that performs washing at an optimum water level and water flow intensity suitable for the amount of clothes (hereinafter referred to as the amount of clothes).

2. Description of the Related Art The present inventors have grasped clothes already put into a washing and dewatering tub by using an electronic control device such as a microcomputer, and set a water level and a flow strength which are optimal for the amount of clothes. Machine control device is proposed.

The control device of this washing machine detects the fluctuation of the water level generated by stirring the clothes in the washing and dewatering tub by driving the stirring blades for a certain period of time by the motor during the stirring operation of the washing and the like by the water level detection unit. The amount of cloth is determined based on the detection result. Further, the water level and the strength of the water flow are determined according to the amount of the cloth. That is, when the detected water level exceeds a preset threshold value, the water level is increased by a predetermined amount, or the water flow by the stirring blade is increased while the water level remains unchanged. If the detected water level does not exceed the threshold, the water level and the strength of the water flow are left as they are,
The operation of reading the detection output of the water level detection unit again is continued until the washing process ends. Thus, the water level and the strength of the water flow that are optimal for the amount of cloth are maintained. It should be noted that the threshold value used at this time does not depend on the elapsed time from the start of washing, and a constant value is set for each water level until the end of washing.

Problems to be Solved by the Invention In the above-described conventional configuration, the threshold value is set to a constant value for each water level until the end of washing, regardless of the elapsed time from the start of washing. For this reason, it is impossible to set the optimum water level and water flow according to the laundry amount. In other words, the amount of water absorbed by the laundry varies depending on the elapsed time since the start of the laundry. Therefore, in the method of keeping the threshold constant, the optimal water level and water flow can be set according to the laundry amount of the laundry. Not something.

The present invention is to solve the above problems, taking into account the effect of water absorption on laundry caused by washing agitation,
Assuming that the threshold value is set according to the elapsed time from the start of washing and for each water level, high-accuracy cloth amount detection is performed, and the optimum water level according to the cloth amount and the strength of the water flow by the stirring blade are determined. It is an object of the present invention to provide a washing machine control device that can be set.

Means for Solving the Problems To achieve the above object, the present invention provides a motor for driving a washing and dewatering tub or a stirring blade, a water supply valve for supplying water to the washing and dewatering tub, and the washing and dewatering. A water level detection unit that detects a water level in the tank, and a control circuit unit that performs energization control of the motor and open / close control of the water supply valve, the control circuit unit reads a detection output from the water level detection unit, This detection output value is compared with a preset threshold value. If the detection output value of the water level detection unit exceeds the threshold value, the water level is increased by a predetermined amount, or the water level is stirred as it is. If the water flow by the wing is strengthened and the detection output value of the water level detection unit does not exceed the threshold value, the detection output of the water level detection unit is read again with the water level and the strength of the water flow by the stirring blade unchanged, and this operation is performed. Continue until washing is complete The threshold value is set for each water level according to the elapsed time from the start of washing.

Action The present invention sets the threshold value of the control circuit unit for each water level according to the elapsed time from the start of washing, thereby preventing a change in water level caused by water absorption into the laundry caused by washing agitation. High-accuracy cloth amount detection that can handle
In addition, the water level can be set according to the amount of cloth and the strength of the water flow by the stirring blade can be set.

Embodiment An embodiment of the present invention will be described below in detail with reference to FIGS.

In FIG. 1, 1 is a stirring blade 8 or a washing and dewatering tub 6.
, A water supply valve for supplying water to the washing and dewatering tub 6, a water level detection unit for detecting the water level in the washing and dewatering tub 6, and an output from the water level detection unit 3. This is a control circuit for controlling the amount of electricity supplied to the motor 1 and the opening and closing of the water supply valve 2. 5 is an outer tub located outside the washing and dewatering tub 6, 7 is laundry put into the washing and dewatering tub 6, 9 is an air trap provided at the bottom of the outer tub 5, and 10 is an air trap 9
An air hose that transmits the internal pressure to the water level detection unit 3.
The water level detecting section 3 includes a pressure detecting section 11 for detecting the pressure in the air trap 9 and a frequency converting section 12 for converting an output of the pressure detecting section 11 into a frequency.

FIG. 2 is an example showing a specific configuration of the pressure detector 11 and the frequency converter 12. 13 is an outer case constituting the exterior of the pressure detection unit 11, 14 is an airtight chamber, 15 is a diaphragm for converting the pressure in the airtight chamber 14 into mechanical displacement, 16 is a diaphragm 15 against the pressure of the airtight chamber 14. A spring for suppressing displacement to an appropriate size, 17 is a cylindrical ferrite core displaced with the movement of the diaphragm 15 arranged at the center of the diaphragm 15,
Reference numeral 18 denotes an annular coil wound in a ring shape so as to surround the direction of displacement of the ferrite core 17, 19 denotes an LC-type self-excited oscillation circuit in which the inductance of the coil 18 is one element of a resonance circuit, and 20 denotes shaping. This is an output terminal for outputting a square wave.

FIG. 3 shows the relationship between the ON period and the OFF period of the motor 1 and the oscillation frequency at which the frequency converter 12 oscillates.
FIG. 4 shows the relationship between the amount of laundry in the specific water level after a lapse of a predetermined time from the start of washing and the oscillation frequency which is the detection output of the water level detection unit 3.

Next, the operation in the above configuration will be described. As shown in FIG. 1, while the stirring blade 8 is not rotating, the water surface in the washing and dewatering tub 6 of the washing machine is horizontal as indicated by a broken line X. When the stirring blade 8 starts rotating, the water surface becomes mortar-shaped as shown by the dashed line Y. At the same time, a flow is generated by the pump action as shown by the arrow, and the water level between the outer tub 5 and the washing and dewatering tub 6 is indicated by a one-dot chain line Yg.
It decreases as shown by. Since the pressure in the air trap 9 indicates the pressure between the outer tub 5 and the washing and dewatering tub 6, the water level in the air trap 9 also drops from the broken line Xt to the one-dot chain line Yt. That is, when the stirring blade 8 rotates, the air trap 9
When the pressure in the water drops and the rotation stops, the water surface reverts to a broken line X
The pressure increases to try to return to. The frequency converter 12 converts this change in pressure into a change in frequency, and
To communicate.

The frequency at which the frequency converter 12 oscillates is determined as follows. When washing is started and the laundry 7 is stirred by the rotation of the stirring blades 8 by the motor 1, the water level in the outer tub 5 decreases. Therefore, the pressure in the air trap 9 also decreases, the diaphragm 15 rises, and the ferrite core 17 is displaced in a direction away from the coil 18. Therefore, the inductance of the coil 18 decreases and the oscillation frequency of the self-excited oscillation circuit 19 increases. Conversely, when the rotation of the stirring blade 8 by the motor 1 is stopped, the stirring of the washing unit passage 7 is also stopped, and the water level between the outer tub 5 and the washing and dewatering tub 6 rises. Accordingly, the pressure in the air trap 9 also increases, and the position of the diaphragm 15 decreases.
That is, the distance between the ferrite core 17 and the coil 18 decreases. Therefore, the inductance of the coil 18 increases,
The oscillation frequency of the self-excited oscillation circuit 19 decreases.

FIG. 3 shows the relationship between the on / off of the motor 1 and the oscillating frequency tested by the inventors using the apparatus of the present embodiment. Self-excited oscillation circuit generated during ON / OFF period 19
Assuming that the maximum value of the oscillation frequency is f-max and the minimum value is f-min, the relationship shown in FIG. 4 exists between the f-min and the cloth amount. FIG. 4 is a characteristic diagram showing the relationship between the amount of laundry and the oscillation frequency at a specific water level tested by the inventors. That is, the amount of cloth when a specific time has elapsed since the start of washing and the f-min corresponding to this amount of cloth are shown. The variation of f-min is obtained by statistically processing a plurality of experimental results. The fourth
The hatched portion in the figure indicates the f-min variability in the appropriate cloth amount range at the specific water level. The actual f-min exists within the range of this variation. A shown in FIG. 4 is a threshold value set in this embodiment. That is, in this embodiment, the threshold value is set to the upper limit of the variation of f-min in the upper limit within the range of the appropriate cloth amount.

FIG. 5 shows the relationship between the upper limit value of f-min and the elapsed time from the start of washing, which were experimented by the inventors. That is, the upper limit value of f-min changes depending on the elapsed time from the start of washing, both when the detergent is used and when the detergent is not used. Therefore, the threshold value A set in the present embodiment is also based on the passage of time as indicated by the threshold value in FIG. As long as the elapsed time since the start of washing,
The threshold setting point A increases with the passage of time. This is because the cloth as the laundry absorbs the water in the washing and dewatering tub 6 with the lapse of time while the elapsed time is short after the start of the washing. In other words, the water level of the washing and dewatering tub 6 is reduced by the cloth absorbing the water,
The water level between the outer tub 5 and the washing and dewatering tub 6 also decreases. Accordingly, the output f-min of the water level detection unit 3 also increases, and as a result, the value of the threshold value A set at the upper limit of the variation of f-min also increases. After a lapse of time from the start of washing and the amount of water absorbed by the cloth is stabilized, the value of f-min is also stabilized, and the value of threshold value A is also stabilized. Further, the value of the threshold value A varies depending on the amount of detergent used. This is because the amount of water absorbed by the cloth varies depending on the amount of the detergent. The threshold value A set in the present embodiment is set to include the upper limit value of the variation due to the detergent amount.

That is, the control device of the washing machine according to the present embodiment is configured such that the value of f-min shown as a hatched portion in FIG. 5 is a threshold value A according to the elapsed time from the start of washing set for each water level. When it becomes larger, it is determined that the cloth amount is too large, and the water level is controlled to be increased by a predetermined amount. Also, while the value of f-min is smaller than the threshold value A corresponding to the elapsed time from the start of washing set for each water level, it is determined that the cloth amount is appropriate, and the water level and the stirring blade The detection output of the water level detection unit 3 is read again without changing the strength of the water flow. If the result of the reading is proper, the reading is continued until the washing process is completed.

Effect of the Invention As described above, the present invention provides a motor for driving a washing and dewatering tub or a stirring blade, a water supply valve for supplying water to the washing and dewatering tub, and a water level for detecting a water level in the washing and dewatering tub. A detection unit, and a control circuit unit that controls the energization of the motor and the opening / closing control of the water supply valve.The control circuit unit reads a detection output from the water level detection unit, and is set in advance with the detection output value. When the detection output value of the water level detection unit exceeds the threshold value, the water level is increased by a predetermined amount, or the water level is increased by the stirring blade while maintaining the water level, and the water level is increased. If the detection output value of the detection unit does not exceed the threshold value, read the detection output of the water level detection unit again without changing the water level and the strength of the water flow by the stirring blade, and continue this operation until washing is completed. And the threshold is As a configuration that is set for each water level according to the elapsed time from the start of washing, it is possible to detect a high-precision cloth amount capable of coping with a change in water level due to water absorption of laundry caused by washing agitation. The water level can be set by setting the optimum water level according to the water level and the stirring blade.
It is of great industrial value.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a control device of a washing machine according to one embodiment of the present invention, FIG. 2 is a cross-sectional view showing a specific configuration example of a pressure detection unit and a frequency conversion unit, and FIG. FIG. 4 is a characteristic diagram showing the relationship between the off period and the oscillation frequency of the frequency conversion unit, and FIG. 4 is a characteristic diagram showing the relationship between the laundry amount of the laundry at a specific water level and the oscillation frequency that is the detection output of the water level detection unit. FIG. 5 is a characteristic diagram showing a relationship between a threshold setting point at a specific water level and an elapsed time from the start of washing. DESCRIPTION OF SYMBOLS 1 ... Motor, 2 ... Water supply valve, 3 ... Water level detection part, 4 ... Control circuit part.

────────────────────────────────────────────────── ─── Continued from the front page (56) References JP-A-63-24990 (JP, A) JP-A-63-262192 (JP, A) JP-A-3-207395 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) D06F 33/02 D06F 37/40 D06F 39/08

Claims (1)

(57) [Claims] A motor for driving a washing and dewatering tub or a stirring blade; a water supply valve for supplying water to the washing and dewatering tub; a water level detecting unit for detecting a water level in the washing and dewatering tub; A control circuit unit for controlling the energization of the motor and controlling the opening / closing of the water supply valve, the control circuit unit reads a detection output from the water level detection unit, and detects the detection output value and a preset threshold value. When the detection output value of the water level detection unit exceeds a threshold value, the water level is increased by a predetermined amount, or the water level is increased and the water flow by the stirring blade is increased, and the detection output value of the water level detection unit is increased. If the value does not exceed the threshold value, the detection output of the water level detection unit is read again while maintaining the water level and the strength of the water flow by the stirring blade, and this operation is continued until washing is completed, and the threshold is set. The value is the time since the start of washing. Washing machine controller set for each level as a function of time.