System and process for detecting a load of clothes in an automatic laundry machine

Abstract

A system and a process for detecting a load of clothes in an automatic laundry machine, comprising a voltage sensor, a rotation sensor, and a control unit associated with a timer, with the voltage sensor, and with the rotation sensor and which is supplied with data representative of the medium torque Mmot of the electric motor in different voltage ranges and with data representative of the acceleration and deceleration reference times (Ta1 and Td1) of the electric motor with the basket in the unloaded condition and containing a load of clothes, between two distinct and predetermined rotation values of the electric motor, so as to calculate the moments of inertia (Jv, Jc) of the basket in the unloaded and in the loaded conditions, said control unit calculating the difference between said moments of inertia (Jc e Jv) of the basket and producing a signal representative of the mass of the load of clothes.

Description

FIELD OF THE INVENTION [0001] The present invention refers to a system to be applied to automatic laundry machines, which allows detecting a load of clothes put into the laundry machine and automatically selecting the level of the washing liquid to be supplied to the machine according to the washing program selected by the user. [0002] The invention further relates to a process for detecting a load of clothes put into the laundry machine and for automatically selecting the level of the washing liquid to be supplied to the machine, as a function of the detected load of clothes. PRIOR ART [0003] There are known different systems for detecting a load of clothes put into a laundry machine and thus defining and controlling, automatically, the amount of the washing liquid, generally water, to be supplied to the machine, more precisely to the tub inside which is seated a basket designed to contain the load of clothes and which is rotatively driven, upon the spin operation, by an electric m...

AI Technical Summary

Benefits of technology

[0013] By reason of the inconveniences and deficiencies of the prior art system for detecting the load of clothes, it is an object of the present invention to provide a system for detecting a load of clothes in an automatic laundry machine, which presents a simple construction of relatively low cost, and high accuracy in detecting the load of clothes placed inside the basket of the machine.

[0014] It is a further object of the present invention to provide a system for detecting a load of clothes as mentioned above, which allows determining, automatically, the level of the washing liquid to be supplied to the tub of the machine as a function of the detected load of clothes.

[0015] It is still a further object of the present invention to provide a process for detecting a load of clothes in an automatic machine, which permits obtaining, accurately, through simple means of relatively low cost, a signal representative of a load of clothes put into the basket of the machine and which determines the level of the washing liquid to be supplied to the machine. DISCLOSURE OF THE INVENTION

[0018] The system mentioned above allows, through the provision of the voltage and rotation sensors and by providing the control unit with a timer, establishing reference data adjusted for each machine in the manufacturing phase, and operational data related to each load of clothes put into the basket, the processing of said data allowing comparing the respective moments of inertia and thence produce a signal which represents, with high accuracy, the load of clothes inserted in the basket and which will be washed, independently of the voltage variations of the power source of the electric motor.

Problems solved by technology

While adequately operating, this prior art system requires complex expensive means and constructions.

This type of prior art system may present mechanical errors produced during manufacture or have the weight sensor located in an inadequate position, impairing the accuracy in detecting the weight of both the clothes and the washing liquid, resulting in washing operations presenting an amount of water out of the desirable standards.

While allowing a certain accuracy in detecting the load of clothes, this prior art solution presents the inconvenience of requiring relatively complex electronic circuits and of not considering the load represented by the friction of the movable parts of the machine, which load varies as a function of the tolerances and of the manufacture and assembly methods of the different components.

Besides the inconveniences above, the prior art solution cited above is subjected to measurement deviations due to the noises produced in the power source as a function of the voltage variations, which can be intense and frequent.

This prior art system does not present a satisfactory accuracy in terms of detecting the load of clothes, particularly when the machine is installed in electric power sources that are subjected to high noise levels.

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