WO2008003710A1

WO2008003710A1 - A washer/dryer

Info

Publication number: WO2008003710A1
Application number: PCT/EP2007/056709
Authority: WO
Inventors: Kerem Erenay; Latif Tezduyar; Alper Baykut
Original assignee: Arcelik Anonim Sirketi
Priority date: 2006-07-04
Filing date: 2007-07-04
Publication date: 2008-01-10
Also published as: TR200808269T1

Abstract

The present invention relates to washer/dryer (1) that can ascertain the weight of the laundry placed therein as close to the actual values as possible before the washing process starts by utilizing the voltage coefficient value already used for adjusting the motor (3) feed voltage without the need for further measurements.

Description

Description A WASHER/DRYER

[0001] The present invention relates to a washer/dryer wherein a weight detecting method is used to determine the weight of the laundry loaded therein providing the efficient operation of the washers.

[0002] In washer/dryers, preferably in washing machines, the amount of water intake, cleaning agents such as the detergent, fabric softener and the washing program and/or the duration is determined according to the type and weight of the laundry emplaced therein. Not knowing the amount of the laundry results in using extra water and cleaning agents and also in the increase of energy consumption from using excess water.

[0003] In the state of the art United States of America patent application no. 20040103485, a washing machine is described that determines the time spent by the washing machine for this work and the acceleration curve by rotating the motor to the 2/5 revolution and senses the amount of load placed in the washing machine via taking these data into consideration.

[0004] In the state of the art German patent application no. 19832292, the description is given for a direct drive washing machine wherein the weight estimation of the laundry loaded in the drum is made by the position that the laundry reaches and the electric current drawn by the motor as the drum rotates about the central axis thereof.

[0005] In the invention explained by the state of the art European Patent no. 0527452, the load is determined by operating and stopping the motor and monitoring the stopping duration and the number of the voltage waves generated by the potentiometer. The amount of load is found by comparing the data values with the reference values.

[0006] The object of the present invention is to design a washer/dryer that determines the weight of the laundry emplaced therein as close to actual values as possible before starting the washing process without the requirement of additional measuring devices or sensors.

[0007] In the washer/dryer of the present invention, the actuation of the drum is maintained by a variable speed motor. In this type of motors, a speed controller is used that compares the actual speed of the motor with a predetermined reference speed and keeps the speed of the motor at the determined level. The output signals of this speed controller are either firing angles or - PWM - pulse width modulation signals depending on the type of the motor and the control card decides on the voltage coefficient based on these signals, regulating the feed voltage of the motor.

[0008] The control card used in the washer/dryer of the present invention determines the amount of load placed in the washer/dryer by comparing the voltage coefficient values ascertained for adjusting the motor feed voltage with the expected voltage coefficient values already stored in the memory thereof. In order to make the assessment, some amount of water, less than the amount required for washing, is taken into the washer/ dryer before the washing and the voltage coefficient is observed. The aim is to determine the load amount by comparing this voltage coefficient value to the expected voltage coefficient value stored in the memory of the control card for every load amount. However, sometimes making a sound assessment with only one comparison is not possible, therefore water intake is continued and the change in the voltage coefficient values is observed as the water amount changes. Accordingly, the voltage coefficient values read for several water levels are compared with the voltage coefficient values in the memory of the control card for a certain load amount and the load amount can be determined correctly.

[0009] After the load amount is determined, this data is used by the control card for deciding on the durations of the procedure and the amount of the water, detergent etc. to be used.

[0010] In an embodiment of the present invention, when the load amount is determined, if the water volume required for washing this amount of load is sufficient, then the control card stops water intake. If the required water volume for the determined load value is not yet reached, then water intake is continued until reaching that volume.

[0011] In another embodiment of the present invention, the load amount data is used in detecting the unbalanced load resulting from the distribution of laundry in the drum.

[0012] The washer/dryer designed to fulfill the objective of the present invention is illustrated in the attached figures, where:

[0013] Rgure 1 - is the schematic view of a washer/dryer.

[0014] Rgure 2 - is the voltage - time graph that shows the entrance voltage being adjusted for feeding the motor in the preferred embodiment of the present invention.

[0015] Rgure 3 - is the voltage, current and firing - time graph that shows the entrance voltage being adjusted for feeding the motor in another embodiment of the present invention.

[0016] Rgure 4 - is the graph that shows the change of voltage coefficient for differing loads based on water volume in a load determining method implemented before a washing phase in the preferred embodiment of the present invention. [0017] The elements illustrated in the figures are numbered as follows:

1. Washer/dryer

2. Drum

3. Motor

4. Speed controller

5. Control card

[0018] The washer/dryer (1) of the present invention, preferably a washing machine, comprises a drum (2) wherein the laundry defined as load is emplaced, providing to wash and spin-dry by rotating about an axis, a variable speed motor (3) that activates this drum (2) and preferably a PI (proportional integral) or PID (proportional integral derivative) type speed controller (4), that compares a predetermined reference speed with the speed of the motor (3) and keeps the speed of the motor (3) at the determined level, a control card (5) that regulates the motor (3) voltage feeding by monitoring the change of the voltage coefficient with respect to time which is determined with the output signals of the speed controller (4) and specifies the load amount emplaced in the drum (2).

[0019] In the washer/dryer (1) of the present invention, the speed controller (4) tries to adjust the actual speed of the motor (3) to the reference speed level by constantly comparing the actual speed with the reference speed. For this adjustment, the control card (5) multiplies the entrance voltage with a coefficient of voltage to specify the voltage (V _app) that will be applied to the motor (3).

[0020] In the preferred embodiment of the present invention, the motor (3) is a brushless direct current (BLDC) motor (3). In this embodiment, the output signals of the speed controller (4) are pulse width modulation signals (PWM). In order to draw the operating speed of the motor (3) to the reference level, the speed controller (4) chops the entrance voltage (V ^) and applies V₁ and V₀ voltages respectively at T _x and T₀ periods, and delivers to the motor (3) phase control switch with square waves. The voltage (V _app) that is converted to the desired value reaches the motor (3) from the motor (3) phase control switch. While the entrance voltage (V _&) is converted as mentioned above at the speed controller (4) applying the resulting voltage (V _app) to the motor (3), the speed controller (4) generates pulse width modulation (PWM) control signals as output signals. The control card (5) starting off with PWM signals reaches the data of T [/(T^T₀) rate change with respect to time. The T [/(T^T₀) rate is called PWM dutycycle. The PWM dutycyle is detected as a graph that changes with respect to time according to the varying power requirements of the motor (3), the PWM dutycyle forms different profiles that define the different operating conditions of the motor (3) in the presence of varying loads confronted by the motor (3).

[0021] In this embodiment, when the entrance voltage (V _dc) is applied on the washer/dryer (1), while the motor (3) rotation speed is kept constant at the desired speed, the change of the PMW dutycycle means that the required power from the motor (3) has changed and the voltage (V ^) applied on the motor (3) changes in direct proportion with the decreasing or increasing PWM dutycycle according to the required power (V _app = PWM dutycycle * V _&). In other words, in this embodiment, the voltage coefficient is the PWM dutycycle. For example, when the entrance voltage (V _&) is controlled by a low value PWM dutycycle, the voltage value (V _app) applied to the motor (3) will be low, when controlled by a high value PWM dutycycle, the voltage value (V _app) applied to the motor (3) will be high (Figure 2).

[0022] In another embodiment of the present invention, the motor (3) is an alternating current (AC) motor (3). In this embodiment, the output signals of the speed controller (4) are firing angle (α) signals. The utilized speed controller (4) is preferably triac. In the motor (3) speed control made by the triac, the ZC - zero cross of the alternating current that flows in waveforms of positive and negative alternations are caught and the speed controller (4) (triac) is fired at spaced apart time delays by referencing to the zero crossing points. These time delays are called firing angle (α). Current is produced, from the zero voltage of the power network, when the triac is fired after the firing angle (α). The triac cannot intervene to cut off the current of the motor (3), the current decreases in the negative alternation of the voltage and when shut off the triac closes to fire again. The speed of the motor (3) is regulated by adjusting the firing angle α. By using PI (Proportional Integral) or PID (Proportional Integral Derivative) control methods, the voltage applied to the motor (3) is reduced by increasing α if the speed of the motor (3) is high, the voltage applied to the motor (3) is increased by decreasing α if the speed of the motor (3) is low (Figure 3). However, the relation of the voltage with the firing angle is not linear. In other words, in this embodiment the coefficient of voltage is a nonlinear function of the firing angle α.

[0023] The voltage coefficient changes with respect to amount of laundry contained and the water volume intake in the washer/dryer (1). In order to determine the amount of laundry (load) placed in the washer/dryer (1), the expected voltage coefficient value corresponding to each load- water pair is recorded in the memory of the control card (5). The voltage coefficient for two different loads in a certain volume of water can be the same. However, all of the voltage coefficient values of an amount of load in different volumes of water are not the same as the voltage coefficient values of another amount of load. Therefore, the amount of load cannot always be correctly ascertained by observing the voltage coefficient value of a certain volume of water. The amount of load can be determined if the voltage coefficient values in more than one volume of water is close to the expected voltage coefficient for a load amount.

[0024] In order to ascertain the load amount placed in the washer/dryer (1), the coefficient of voltage is observed by initially taking a volume of water less than the amount for washing in into the drum (2), then water is taken in incrementally increasing amounts and the voltage coefficient is continued to be observed for each incremental amount (water volume) and at each increment the voltage coefficient value is compared by the control card (5) with the value stored in the memory thereof. As a result of the comparisons done up till that moment, if the voltage coefficient values corresponding to a load amount (X) match while none of the values corresponding to other load amounts matches, then the control card (5) decides that the load is the amount (X).

[0025] For example, in the preferred embodiment of the present invention wherein a brushless direct current motor (3) is used, in a 52 rpm washing, when the motor (3) is operated by taking in 4 liters of water into the drum (2), the control card (5) decides that the load is 0 kg. if the voltage coefficient is below 0.1 and around 0.075. For other load amounts the voltage coefficient values are close to each other. In this case, water intake into the drum (2) continues, the values start to be different when 4 and 6 liters are reached respectively. The control card (5) decides that the load is 1 kg. if the voltage coefficient value is decreasing when volume changes from 4 liters to 6 liters, and 3 kg. if it is increasing (Figure 4).

[0026] The amounts of required washing, rinsing water, detergent amounts and/or softener amount and at least one of the suitable washing durations for each load amount are recorded in the memory of the control card (5). For the load amount (X) specified by the control card (5) the amounts of water, detergent and/or softener and the process durations are adjusted.

[0027] In an embodiment of the present invention, when the load amount (X) is determined, if the water volume reached is sufficient for washing the load (X) effectively, the control card (5) stops the water intake. If the required volume of water is not reached for the determined load amount (X), then water intake continues until reaching that volume. After this phase, the washer/dryer (1) implements pre-washing, washing, rinsing and/or spin-drying or a combination of these depending on the selection specified by the user. During these phases the process durations and the amounts of water, detergent etc. are decided on by using the load amount (X) dala ascertained by the control card (5).

[0028] In another embodiment of the present invention, when the load amount (X) is determined, the control card (5) uses this information to ascertain the unbalanced load in the drum (2) resulting from the distribution of laundry.

[0029] By means of the washer/dryer (1) of the present invention, the weight of the laundry placed therein before the washing process starts, that is the load amount (X) is ascertained as close to actual values as possible. By this means, water and detergent savings is possible and extra energy consumption is prevented as well. Furthermore, since the already used voltage coefficient value is utilized for adjusting the motor (3) feed voltage in determining the load amount (X), the need for further measurements and the use of additional measurement devices or sensors is eliminated. The washer/ dryer (1) is enabled to operate more efficiently and reliably.

Claims

[0001] A washer/dryer (1) comprising a drum (2) wherein the laundry (load) is emplaced, providing to wash and spin-dry by rotating about an axis, a variable speed motor (3) that activates this drum (2) and a speed controller (4) that compares a predetermined reference speed with the actual speed of the motor (3) and keeps the speed of the motor (3) at the determined level, a control card (5) that regulates the motor (3) voltage feed by monitoring the change of the voltage coefficient with respect to time which is determined with the output signals of the speed controller (4) and characterized in that the control card (5) has voltage coefficient values corresponding to each pair of load- water amount in its memory, starts to observe the voltage coefficient by initially taking in a volume of water less than the amount necessary for washing into the washer/dryer (1), then continues to observe the voltage coefficient for each increment while taking in water in incrementally increasing amounts, decides on the load amount placed in the drum (2) by comparing the measured voltage coefficient with the value in the memory thereof.

[0002] A washer/dryer (1) as in Claim 1, characterized by a brushless motor (3) operating with direct current wherein the voltage coefficient is PWM duty^cle.

[0003] A washer/dryer (1) as in Claim 1, characterized by a motor (3) that operates with alternating current (AC) wherein the voltage coefficient is a function of the firing angle α.

[0004] A washer/dryer (1) as in any one of the above claims, characterized by a control card (5) wherein at least one of the required amounts of washing, rinsing water, detergent and/or softener and durations of the suitable washing for each load amount is recorded in the memory thereof and for the specified load amount (X), adjusts the amounts of water, detergent and/or softener and the process durations.

[0005] A washer/dryer (1) as in any one of the above claims, characterized by a control card (5) that stops the water intake if the water volume reached is sufficient for washing the load (X) effectively when the load amount (X) is determined, if the required volume of water is not reached for the specified load amount (X), then continues water intake until reaching that volume.

[0006] A washer/dryer (1) as in any one of the above claims, characterized by a control card (5) that uses the information of the specified load amount (X) to ascertain the unbalanced load resulting from distribution of laundry in the drum (2).