A household appliance with efficient drying and a control method related to the same

Abstract

The present invention relates to a household appliance (100) comprising a body (1), a drum (2) for placing laundry; a tub (3) which surrounds the drum (2) so as to allow the drum (2) to make rotational movement in the body (1); a motor (4) which provides power for the movement of the drum (2); at least one heating channel (6) which ensures that the drying air heated by means of a heating unit (5) comprising at least one heater (51) and at least one fan (52) operating in coordination for use in drying the laundry is delivered into the drum (2); a first temperature sensor (7) which is arranged in the heating channel (6) so as to measure the temperature of the heated drying air delivered into the heating channel (6); and a second temperature sensor (8) which is arranged so as to measure the temperature at any point of the drum (2) heated by the drying air; and also relates to a control method for the said household appliance (100).

Description

[0001] The present invention relates to a household appliance which enables the moisture to be homogeneously distributed among the laundry in the drum, which enables the laundry load to be determined effectively and which provides energy saving during the drying process, and to a control method which is executed in the said household appliance.

[0002] In the state of the art laundry washing / drying machines, the laundry loaded into the drum is dried by means of the drying air heated by passing through a heat source. The heated drying air absorbs the moisture from the wet laundry, and the absorbed moisture is then condensed in the body of the laundry drying machine and transferred, by means of a pump assembly, either to a storage tank which can be easily accessed by the user or to the wastewater drain. During the drying process, energy is consumed both for the heater and for the movement of the drum. At this point, accurately determining the laundry load and the amount of moisture in the laundry is of great importance in terms of reaching the desired moisture level at the end of the drying process and saving energy in the process.

[0003] There are state of the art laundry drying machines and methods developed to accurately determine the laundry load and moisture. For example, in state of the art Patent Document No. EP1961858B1, a laundry drying machine is disclosed, comprising a rotating drum wherein the laundry to be dried is loaded, one or more laundry lifters which are disposed on the inner circumferential surface of the drum, and an electric circuit which is configured to determine the electrical resistance and / or conductivity of the laundry in the rotating drum. Each laundry lifter comprises at least one first electrode and at least one second electrode which are configured to contact the laundry and which are electrically isolated from each other, and a first conductive contact member and a second conductive contact member which extend along the outer circumferential surface of the drum. The first conductive contact member and the second conductive contact member are electrically connected to the first electrode and the second electrode, respectively. The conductive contact members are electrically isolated from each other, and a first sliding member and a second sliding member are configured to slide along the first conductive contact member and the second conductive contact member. As the drum rotates, a control unit connected to the said components measures the amount of electricity depending on the residual moisture content in the dried laundry.

[0004] However, while detecting the load amount in the dry laundry is relatively possible, damp or wet laundry may give variable results. Since the water retention capacity varies depending on the type of textile, the problem of failing to achieve a homogeneous moisture level among the laundry items, which are intended to be dried in the same drum but have different water retention capacities, arises. This causes some laundry items to remain damp when removed from the laundry drying machine and causes other items to be excessively dried. Therefore, there is still a need for machines and methods wherein the moisture in the laundry is homogenized and measured such that load detection and drying are performed more efficiently.

[0005] The aim of the present invention is the realization of a household appliance and a control method for the same, wherein the wet laundry load is measured with higher accuracy compared to the state of the art embodiments, and even when laundry items with different water retention capacities are subjected to the drying process in the same cycle, all laundry items are removed from the drum at the end of the drying process with a uniform and desired moisture level. Thus, it becomes possible to effectively dry all laundry items and achieve energy saving.

[0006] The present invention discloses a household appliance comprising a body; a drum for placing the laundry; a tub which surrounds the drum so as to allow the drum to make rotational movement in the body; a motor which provides power for the movement of the drum; at least one heating channel which ensures that the drying air heated by means of a heating unit comprising at least one heater and at least one fan operating in coordination for use in drying the laundry is delivered into the drum; a first temperature sensor which is arranged in the heating channel so as to measure the temperature of the heated drying air delivered into the heating channel; and a second temperature sensor which is arranged so as to measure the temperature at any point of the drum heated by the drying air. The household appliance of the present invention further comprises a control unit which is configured to determine a primary load value related to the laundry load in the drum by processing the information on the amount of power required for the movement of the drum at a defined second rotation speed, following a spin-drying process comprising the movement of the drum at a first rotation speed of 600 rpm or higher and wherein a portion of the moisture in the laundry is removed. Accordingly, during the spin-drying process, the drum preferably performs rotational movement at a first rotation speed at which the wet laundry sticks to the inner wall of the drum. The said first rotation speed is in the range of 600 rpm to 1700 rpm. In an embodiment of the present invention, the control unit is configured to continue the said spin-drying process for at least 15 minutes. In an embodiment of the present invention, the duration of the spin-drying process is between 15 and 30 minutes. By means of the spin-drying process, the excess water in the laundry with relatively higher water retention capacity is removed, and the moisture values of the laundry items in the drum are brought to similar levels. In other words, a homogeneous moisture level is achieved in the drum. In the present invention, the control unit ensures that the laundry load in the drum, and hence the amount of moisture, are determined following the said spin-drying process. Thus, the laundry load is determined based on the laundry of which the moisture has already been homogenized. Accordingly, the control unit is configured to determine a primary load value following the spin-drying process. The said primary load value may be the total weight of the damp laundry or the amount of moisture on the laundry. The primary load value of the present invention is calculated based on the power required to apply a second rotation speed defined in the control unit to the rotational movement of the drum and required to perform the said movement. The said second rotation speed is in the range of 50 rpm to 1700 rpm, which is the same as or different from the first rotation speed. In an embodiment of the present invention, during the rotational movement of the drum at the second rotation speed, the laundry in the drum remains stuck to the inner wall of the drum. In an embodiment of the present invention, during the rotational movement of the drum at the second rotation speed, the amount of power drawn from the motor and, hence the laundry load in the drum may be calculated based on the torque value or the current value of the motor. In an embodiment of the present invention, the said motor is an rpm-controlled motor. In an embodiment of the present invention, the moment of inertia and the friction are used as indicators for determining the laundry load amount in the drum. Accordingly, during the period the current is supplied to the motor, additional torque is applied, and the rotation dynamics of the drum are used to calculate the moment of inertia and the friction starting from a constant speed.

[0007] In an embodiment of the present invention, the control unit is configured to adjust the parameters related to the heating unit and / or the drum movement during a drying process performed after the spin-drying process based on the primary load value determined after the spin-drying process. In this embodiment of the present invention, the said parameters are selected from a list comprising fan speed, drum speed, heater operation duration, and heater operation frequency before the drying process. Thus, the household appliance of the present invention consumes energy specifically based on the laundry load in the drum, providing energy savings. In an embodiment, a plurality of drying parameters can be defined by the user to the control unit before the drying process. The control unit may directly apply the said defined parameters or select those suitable for the determined laundry load from among the parameters defined as a list. At the end of the drying process of the present invention, it becomes possible to remove all laundry items from the drum at the desired homogeneous moisture level.

[0008] In an embodiment of the present invention, the household appliance further comprises a strain gauge which is arranged to measure the amount of elongation along an axis perpendicular to the rotational movement axis during the rotational movement of the drum at the second rotational speed, and to transmit the data to the control unit. In this embodiment of the present invention, the control unit is configured to process the elongation amount data received from the strain gauge and to determine an auxiliary load value related to the laundry load in the drum. In this embodiment, another load value in addition to the primary load value calculated based on the power drawn from the motor is determined. In this embodiment, the control unit may process both the primary load value and the auxiliary load value together so as to determine an optimum load value.

[0009] In an embodiment of the present invention, the household appliance further comprises a motor control unit which is associated with the motor and which enables the power required for the movement of the drum at the second rotational speed to be measured. The said motor control unit may be provided on or in connection with the motor. In an embodiment of the present invention, the motor control unit is a motor board. In this embodiment, the motor board is configured to measure at least one of the parameters which are the torque applied to the motor, the current value, the moment of inertia, and the friction.

[0010] In an embodiment of the present invention, the control unit is configured to determine a secondary load value related to the laundry load in the drum by processing the temperature data received from the first temperature sensor and the second temperature sensor within a certain time interval during a drying process wherein the heating unit is active. Thus, the information related to the moisture content in the drum can be obtained at any time before or during the spin-drying process or a drying process performed thereafter. The difference between the temperature values measured by the first temperature sensor and the second temperature sensor provides an estimate related to the laundry load and the moisture level in the drum. For example, a decrease in the rate of change of the said difference is an indicator that the moisture in the laundry is gradually decreasing. In an embodiment, the said time interval is adjusted by controlling the difference between the temperature data received from the first temperature sensor and the temperature data received from the second temperature sensors or the rate of change in the said temperature data and by deactivating the heating unit upon reaching a target difference value or rate of change. Accordingly, the control unit is configured to control the difference between the temperature data received from the first temperature sensor and the temperature data received from the second temperature sensor or the rate of change in the said temperature data during the drying process wherein the heating unit is active, and to terminate the said drying process by deactivating the heating unit upon reaching a target difference value or rate of change. The said target difference value refers to a value at which the difference between the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor decreases relative to the initial value. Similarly, the target rate of change refers to a value at which the difference per unit time between the temperature measured by the first temperature sensor and the temperature measured by the second temperature sensor decreases relative to the initial value. A decrease in the difference value or the rate of change shows that the moisture in the drum has decreased and hence, that the drying process can be terminated. Accordingly, a difference value or a rate of change value based on the desired final moisture level may be defined in the control unit before the drying process.

[0011] In an embodiment of the present invention, the second temperature sensor is positioned under the drum so as to remain between the tub and the drum while the household appliance is in use. Thus, the extent to which the drying air heated by the heating unit is cooled by the moisture in the laundry, and hence, the effectiveness of the heated drying air in removing moisture from the laundry, can be measured more accurately.

[0012] In an embodiment of the present invention, the household appliance of the present invention is a laundry dryer.

[0013] In another embodiment of the present invention, the household appliance of the present invention is a laundry washer and dryer.

[0014] The present invention also relates to a control method for the household appliance of the present invention, comprising the following steps in order: v. partially removing the moisture from the laundry by means of the rotational movement of the drum at a first rotational speed of 600 rpm or above, vi. increasing the drum speed to a second rotational speed, vii. transmitting the data regarding the amount of power required for the rotational movement of the drum at the second rotational speed from a motor control unit associated with the motor to the control unit, and viii. determining a primary load value related to the laundry load in the drum based on the data received by the control unit.

[0015] Here, the step (v) may also be referred to as the spin-drying step. During the said step, the drum performs rotational movement at a first rotation speed at which the wet laundry sticks to the inner wall of the drum. In an embodiment, the said first rotation speed is in the range of 600 rpm to 1700 rpm. In an embodiment of the control method of the present invention, the step (v), that is the spin-drying step, is performed for at least 15 minutes, preferably for 15 to 30 minutes. By means of the said step, the excess water in the laundry with relatively higher water retention capacity is removed, and the moisture values of the laundry items in the drum are brought to similar levels. In other words, a homogeneous moisture level is achieved in the drum. Following the spin-drying step, in the step (vi), the drum is brought to a rotational speed in the range of 50 rpm to 1700 rpm, which may be the same as or different from the first rotational speed. During the step (vii), the amount of power drawn from the motor during the constant speed at the second rotational speed can be calculated. In an embodiment of the present invention, the said motor is an rpm-controlled motor. In an embodiment, the said motor control unit is a motor board which is configured to measure at least one of the parameters which are the torque applied to the motor, the current value, the moment of inertia, and the friction. Accordingly, during the period the current is supplied to the motor, additional torque is applied, and the rotation dynamics of the drum are used to calculate the moment of inertia and the friction starting from a constant speed. In the step (viii), the control unit makes an estimation regarding the laundry load and the amount of moisture in the laundry based on the measured parameters. In the method of the present invention, the laundry load in the drum is determined after the spin-drying step, and thus, the laundry load is determined based on laundry items of which the moisture level has already been homogenized. In the step (viii), the said primary load value may be the total weight of the damp laundry or the amount of moisture on the laundry.

[0016] In an embodiment, the method of the present invention further comprises the following steps to be performed either before the step (v) or during the step (v): i. Activating the heating unit ii. Transmitting the temperature data received from the first temperature sensor and the second temperature sensor to the control unit iii. Processing the received temperature information and deactivating the heating unit by the control unit when the difference and / or rate of change between the said values reaches a predetermined value iv. Determining a secondary load value related to the laundry load in the drum based on the temperature data received by the control unit

[0017] In this embodiment, a secondary load value is determined in addition to the primary load value, or prior to the determination of the primary load value. Thus, the accuracy of the laundry load estimate made by the control unit using the primary load value can be improved or verified. In this embodiment, the drying process is applied to the laundry in the drum between the steps (i) and (iv). In an embodiment of the present invention, the drum performs the rotational movement at a constant or variable rotational speed throughout the steps (i) to (iv). The heating unit comprises a heater and preferably a fan which is positioned downstream of the heater in the direction of the air flow. Accordingly, in the step (i), the control unit activates the heater and the fan. Thus, the drying air is delivered into the drum in the heated state. First measurements are taken just before or simultaneously with the delivery of the heated drying air into the drum, and measurements from the said sensors are continuously taken and transmitted to the control unit at regular intervals until the step (iii). In the step (iii), the control unit determines when to deactivate the heating unit, i.e., terminate the drying process, based on the difference or the rate of change between the values measured by the two sensors. In the step (iv), the control unit also processes the temperature data received from the sensors, calculates the difference and / or the rate of change therebetween, and determines the secondary load value regarding the laundry load in the drum accordingly. The said secondary load value is an estimation made by the control unit and, in an embodiment of the present invention, is used as a preliminary value in the determination of the primary load value. In another embodiment of the present invention, the secondary load value can be used to verify the primary load value.

[0018] In this embodiment, the method of the present invention further comprises the following steps, in sequence, performed after the step (viii): ix. Determining a category corresponding to the secondary load value determined in the step (iv) from among the categories predefined in the control unit according to different load ranges x. dividing the category determined in the step (ix) into predefined subcategories in the control unit according to different load ranges, each associated with different drying parameters, and classifying the primary load value determined in the step (viii) into one of these subcategories xi. drying the laundry in the drum according to at least one of the parameters specifically defined for the subcategory to which the primary load value is assigned, such as fan speed, drum speed, heater operation duration, or heater operation frequency.

[0019] Accordingly, when both a primary load value and a secondary load value are determined in relation to the laundry load in the drum, a categorization is first performed based on the secondary load value determined via the first temperature sensor and the second temperature sensor. A plurality of categories, representing different load value ranges, and a plurality of subcategories with the said categories, representing different load value ranges, are predefined in the control unit. There may be three categories, which can be, for example, "low load", "medium load", and "high load". Accordingly, there may be six subcategories, which can be, for example, "low light load", "low heavy load", "medium light load", "medium heavy load", "high light load", and "high heavy load". In the step (ix), the control unit determines to which of these categories the secondary load value belongs. Afterwards, in the step (x), by using the primary load value determined by means of the motor power data, it is determined to which subcategory the laundry load in the drum belongs. In the step (xi), the drying parameters specifically defined for the identified subcategory are activated by the control unit. The control unit may directly apply the said defined parameters or select those suitable for the determined laundry load from among the parameters defined as a list. The said parameters can be defined by the user on the control unit before the drying process. By means of this embodiment, the laundry load in the drum is determined in a two-stage manner, which ensures that a more accurate estimation for the amount of moisture in the laundry is made and a more efficient and energy-saving drying process is performed.

[0020] In an alternative embodiment, the method of the present invention further comprises, following the step (viii), respectively, the following steps: ix. grouping the primary load value determined in the step (viii) based on different load ranges and including the same in one of the predefined categories on the control unit, each of which is assigned different drying parameters x. drying the laundry in the drum according to at least one of the parameters specifically defined for the category to which the primary load value is assigned, such as fan speed, drum speed, heater operation duration, or heater operation frequency.

[0021] In this embodiment, only the primary load value determined by means of the motor power data is used for categorization. A plurality of categories representing different load value ranges are predefined in the control unit. There may be three categories, which can be, for example, "low load", "medium load", and "high load". In the step (ix), the control unit determines to which of these categories the primary load value belongs. After this step, in the step (x), the drying parameters specifically defined for the identified category are activated by the control unit. The control unit may directly apply the said defined parameters or select those suitable for the determined laundry load from among the parameters defined as a list. The said parameters can be defined by the user on the control unit before the drying process. Determining the primary load value after the step (v), namely the spin-drying step, results in effective outcomes in terms of correctly including the laundry load in the appropriate category, drying according to the suitable parameters, and removing the laundry from the drum at the desired moisture level. Moreover, since only the necessary amount of energy is consumed, energy savings are provided.

[0022] The cooking device realized in order to attain the aim of the present invention is illustrated in the attached figures, where: Figure 1 - is the perspective view of the household appliance in an embodiment of the present invention, partially showing the interior of the body. Figure 2 - is the schematic view of the household appliance in an embodiment of the present invention.

[0023] The elements illustrated in the figures are numbered as follows: 100. Household appliance 1. Body 2. Drum 3. Tub 4. Motor 5. Heating unit 51. Heater 52. Fan 6. Heating channel 7. First temperature sensor 8. Second temperature sensor 9. Control unit 10. Strain gauge 11. Motor control unit X. Rotational movement axis

[0024] As shown in Figure 1, the household appliance (100) of the present invention comprises a body (1), a drum (2) for placing laundry; and a tub (3) which surrounds the drum (2) so as to allow the drum (2) to make rotational movement in the body (1) Referring to Figure 2, the household appliance (100) further comprises a motor (4) which provides power for the movement of the drum (2); at least one heating channel (6) which ensures that the drying air heated by means of a heating unit (5) comprising at least one heater (51) and at least one fan (52) operating in coordination for use in drying the laundry is delivered into the drum (2); a first temperature sensor (7) which is arranged in the heating channel (6) so as to measure the temperature of the heated drying air delivered into the heating channel (6); and a second temperature sensor (8) which is arranged so as to measure the temperature at any point of the drum (2) heated by the drying air. As shown in Figure 2, in an embodiment of the present invention, the second temperature sensor (8) is positioned under the drum (2) so as to remain between the tub (3) and the drum (2) while the household appliance (100) is in use.

[0025] Additionally, the household appliance (100) of the present invention comprises a control unit (9). The control unit (9) is configured to determine a primary load value related to the laundry load in the drum (2) by processing the information on the amount of power required for the movement of the drum (2) at a defined second rotation speed, following a spin-drying process comprising the movement of the drum (2) at a first rotation speed of 600 rpm or higher and wherein a portion of the moisture in the laundry is removed. The said primary load value may be the total weight of the damp laundry or the amount of moisture on the laundry.

[0026] During the spin-drying process, the first rotational speed is set by the control unit (9) to a value between 600 rpm and 1700 rpm such that the wet laundry sticks to the inner wall of the drum (2). The spin-drying process is continued at the set speed for at least 15 minutes, preferably for 15-30 minutes. The spin-drying process ensures that the excess water in the laundry with relatively higher water retention capacity is removed, and a homogeneous moisture value is achieved in the drum. When the drum (2) shifts to the second rotational speed, the laundry, which is partially dehumidified by the spin-drying process, preferably remains stuck to the inner wall of the drum (2). The said second rotation speed may be in the range of 50 rpm to 1700 rpm, which is the same as or different from the first rotation speed. In the preferred embodiment, the second rotational speed is set to a value lower than the first rotational speed such that the laundry remains stuck to the inner wall of the drum (2). The power consumed by the motor (4) during the rotation of the drum (2) at the second rotational speed can be calculated based on the torque value and / or the current value and / or the moment of inertia and / or the friction of the motor (4). The control unit (9) processes the said calculated value and detects the laundry load in the drum (2), in other words, the primary load value.

[0027] In the preferred embodiment of the present invention, the control unit (9) also plays a role in performing a drying process performed after the said spin-drying process. Accordingly, the control unit (9) is configured to adjust the parameters related to the heating unit (5) and / or the drum (2) movement to be applied during the drying process based on the primary load value determined after the spin-drying process. A plurality of drying parameters can be defined by the user to the control unit (9) before the drying process. The control unit (9) may directly apply the said defined parameters or select those suitable for the determined laundry load from among the parameters defined as a list. In an embodiment, the said parameters is as a list comprising the fan (52) speed, the drum (2) speed, the heater (51) operation duration, and the heater (51) operation frequency. To perform the effective drying of the laundry in the drum, the control unit (9) adjusts at least one of the said parameters according to the primary load value determined after the spin-drying process.

[0028] As shown in Figure 2, in an embodiment, the household appliance (100) of the present invention may comprise a strain gauge (10) which is arranged to measure the amount of elongation in an axis perpendicular to the rotational movement axis (X) during the movement of the drum (2) at the second rotational speed and transmit the same to the control unit (9). The said strain gauge (10) is mounted on the inner wall of the drum (2) or, as in Figure 2, on the outer wall. By means of the said position, the strain gauge (10) is enabled to take direct measurements regarding the movement of the drum (2). In this embodiment, the control unit (9) processes the elongation information received from the strain gauge (10) and further determines an auxiliary load value related to the laundry load in the drum (2). The control unit (9) may use the said auxiliary load value to verify the primary load value and / or evaluate the primary and auxiliary load values together to determine an optimum load value.

[0029] In a preferred embodiment of the household appliance (100), a motor control unit (11) functionally associated with the motor (4) is provided. The motor control unit (11) is preferably an electronic motor board and plays a role in the measurement of the power required for the movement of the drum (2) at the second rotational speed. The power required for the movement of the drum (2) at the second rotational speed is determined by the motor control unit (11) measuring, while the drum (2) rotates at the second rotational speed, at least one of the parameters which are the torque applied to the motor (4), the current value, the moment of inertia, and the friction, and transmitting the data to the control unit. Accordingly, during the period the current is supplied to the motor (4), additional torque is applied, and the rotational movement dynamics of the drum are used to calculate the moment of inertia and the friction starting from a constant speed.

[0030] In an embodiment of the present invention, the control unit (9) is also in communication with the first temperature sensor (7) and the second temperature sensor (8) so as to ensure that the laundry load in the drum (2) is detected in two stages. Accordingly, the control unit (9) determines a secondary load value related to the laundry load in the drum (2) by processing the temperature data received from the first temperature sensor (7) and the second temperature sensor (8) within a certain time interval during a drying process wherein the heating unit (5) is active. Moreover, the control unit (9) is configured to control the difference between the temperature data received from the first temperature sensor (7) and the temperature data received from the second temperature sensor (8) or the rate of change in the said temperature data and to deactivate the heating unit (5) upon reaching a target difference value or rate of change. The difference between the temperature values measured by the first temperature sensor (7) and the second temperature sensor (8) provides an estimate related to the laundry load and the moisture level in the drum. For example, a decrease in the said difference or rate of change of the said difference is an indicator that the moisture in the laundry is gradually decreasing. This shows that the target difference value or the rate of change is close, and therefore, the heating unit (5) can be deactivated. Accordingly, a difference value or a rate of change value based on the desired final moisture level may be defined in the control unit (9) before the said drying process.

[0031] In the preferred embodiment, the household appliance (100) of the present invention is a drying machine suitable for drying laundry or a laundry washing / drying machine suitable for washing and drying laundry.

[0032] The present invention also relates to a control method for the household appliance (100) of the present invention and comprises the following steps in order: v. partially removing the moisture from the laundry by means of the rotational movement of the drum (2) at a first rotational speed of 600 rpm or above, vi. increasing the drum (2) speed to a second rotational speed, vii. transmitting the data regarding the amount of power required for the rotational movement of the drum (2) at the second rotational speed from a motor control unit (11) associated with the motor (4) to the control unit (9), and viii. determining a primary load value related to the laundry load in the drum (2) based on the data received by the control unit (9).

[0033] Here, the step (v) may also be referred to as the spin-drying step. During this step, the drum (2) rotates at a first rotational speed between 600 rpm and 1700 rpm such that the wet laundry sticks to the inner wall of the drum (2). The said step is continued for at least 15 minutes, preferably for 15-30 minutes. In the step (v), the laundry which has been partially dehumidified is then rotated in the step (vi) at a rotational speed ranging from 50 rpm to 1700 rpm, which may be the same as or different from the first rotational speed. As the drum (2) continues to rotate at the second rotational speed, in the step (vii), the motor control unit (11) measures at least one of the parameters which are the torque applied to the motor (4), the current value, the moment of inertia, and the friction and transmits the data to the control unit (9). Accordingly, during the period the current is supplied to the motor (4), additional torque is applied, and the rotation dynamics of the drum (2) are used to calculate the moment of inertia and the friction starting from a constant speed. In the step (viii), the control unit (9) determines the primary load value regarding the laundry load and the amount of moisture in the laundry based on the measured parameters. In the method of the present invention, the laundry load in the drum is determined after the spin-drying step, and thus, the laundry load is determined based on laundry items of which the moisture level has already been homogenized. In the step (viii), the said primary load value may be the total weight of the damp laundry or the amount of moisture on the laundry.

[0034] In an embodiment of the invention, the control method of the present invention further comprises the following steps to be performed before the step (v) or during the step (v) in order: i. Activating the heating unit (5) ii. Transmitting the temperature data received from the first temperature sensor (7) and the second temperature sensor (8) to the control unit (9) iii. Processing the received temperature information and deactivating the heating unit (5) by the control unit (9) when the difference and / or rate of change between the said values reaches a predetermined value iv. Determining a secondary load value related to the laundry load in the drum (2) based on the temperature data received by the control unit (9).

[0035] In this embodiment, a secondary load value is determined in addition to the primary load value, or prior to the determination of the primary load value. Thus, the accuracy of the laundry load estimate made by the control unit using the primary load value can be improved or verified. In this embodiment, from the steps (i) to (iv), a drying process and a load detection process are simultaneously applied to the laundry in the drum (2). In the step (i), the control unit (9) activates the heater (51) and the fan (52). Thus, the drying air is delivered into the drum (2) in the heated state. First measurements are taken just before or simultaneously with the delivery of the heated drying air into the drum (2). Measurements from the said sensors (7 and 8) are continuously taken and transmitted to the control unit (9) at regular intervals until the step (iii). In the step (iii), the control unit (9) determines when to deactivate the heating unit (5), i.e., terminate the drying process, based on the difference or the rate of change between the temperature values simultaneously measured by the first temperature sensor (7) and the second temperature sensor (8). On the other hand, in the step (iv), the control unit (9) calculates the said difference and / or rate of change and, hence, determines the secondary load value related to the laundry load in the drum (2).

[0036] In different embodiments of the present invention, the primary load value and the secondary load value can be processed by the control unit (9) in various ways to be used for optimizing and ultimately determining the laundry load. In an embodiment of the method of the present invention wherein both the primary load value and the secondary load value are used to determine the drying parameters, the method further comprises the following steps to be performed after the step (viii) in order: ix. determining a category corresponding to the secondary load value determined in the step (iv) from among the categories predefined in the control unit according to different load ranges x. dividing the category determined in the step (ix) into predefined subcategories in the control unit according to different load ranges, each associated with different drying parameters, and classifying the primary load value determined in the step (viii) into one of these subcategories xi. drying the laundry in the drum (2) according to at least one of the parameters specifically defined for the category to which the primary load value is assigned, such as fan (52) speed, drum (2) speed, heater (51) operation duration, or heater (51) operation frequency.

[0037] Accordingly, a categorization is first performed based on the secondary load value determined by means of the first temperature sensor (7) and the second temperature sensor (8). A plurality of categories, representing different load value ranges, and a plurality of subcategories with the said categories, representing different load value ranges, are predefined in the control unit (9). In the step (ix), the control unit (9) determines to which of these categories the secondary load value belongs. Afterwards, in the step (x), by using the primary load value determined by means of the calculated motor power data, it is determined to which subcategory the laundry load in the drum belongs. In the step (xi), the drying parameters specifically defined for the identified subcategory are activated by the control unit (9). The control unit (9) may directly apply the said defined parameters or select those suitable for the determined laundry load from among the parameters defined as a list. The said parameters can be defined by the user on the control unit before the drying process.

[0038] In another embodiment of the method of the present invention wherein only the primary load value is used to determine the drying parameters, the method further comprises the following steps to be performed after the step (viii) in order: ix. grouping the primary load value determined in the step (viii) based on different load ranges and including the same in one of the predefined categories on the control unit (9), each of which is assigned different drying parameters x. drying the laundry in the drum (2) according to at least one of the parameters specifically defined for the category to which the primary load value is assigned, such as fan (52) speed, drum (2) speed, heater (51) operation duration, or heater (51) operation frequency.

[0039] In this embodiment, a plurality of categories representing different load value ranges are predefined in the control unit (9). In the step (ix), the control unit (9) determines to which of these categories the primary load value belongs. After this step, in the step (x), the drying parameters specifically defined for the identified category are activated by the control unit (9). The control unit (9) may directly apply the said defined parameters or select those suitable for the determined laundry load from among the parameters defined as a list. The said parameters can be defined by the user on the control unit (9) before the drying process.

Claims

1. A household appliance (100) comprising a body (1), a drum (2) for placing laundry; a tub (3) which surrounds the drum (2) so as to allow the drum (2) to make rotational movement in the body (1); a motor (4) which provides power for the movement of the drum (2); at least one heating channel (6) which ensures that the drying air heated by means of a heating unit (5) comprising at least one heater (51) and at least one fan (52) operating in coordination for use in drying the laundry is delivered into the drum (2); a first temperature sensor (7) which is arranged in the heating channel (6) so as to measure the temperature of the heated drying air delivered into the heating channel (6); and a second temperature sensor (8) which is arranged so as to measure the temperature at any point of the drum (2) heated by the drying air, characterized by a control unit (9) which is configured to determine a primary load value related to the laundry load in the drum (2) by processing the information on the amount of power required for the movement of the drum (2) at a defined second rotation speed, following a spin-drying process comprising the movement of the drum (2) at a first rotation speed of 600 rpm or higher and wherein a portion of the moisture in the laundry is removed.

2. A household appliance (100) as in Claim 1, characterized by the control unit (9) which is configured to adjust the parameters related to the heating unit (5) and / or the drum (2) movement during a drying process performed after the spin-drying process based on the primary load value determined after the spin-drying process.

3. A household appliance (100) as in Claim 2, characterized by the control unit (9) which is configured to adjust, during the drying process performed after the spin-drying process, at least one of the parameters which are the fan (52) speed, the drum (2) speed, the heater (51) operation duration, and the heater (51) operation frequency according to the primary load value determined after the spin-drying process.

4. A household appliance (100) as in any one of the above claims, characterized by a strain gauge (10) which is arranged to measure the amount of elongation in an axis perpendicular to the rotational movement axis (X) during the movement of the drum (2) at the second rotational speed and transmit the same to the control unit (9).

5. A household appliance (100) as in Claim 4, characterized by the control unit (9) which processes the elongation information received from the strain gauge (10) and determines an auxiliary load value related to the laundry load in the drum (2).

6. A household appliance (100) as in any one of the above claims, characterized by a motor control unit (11) which is associated with the motor (4) and which enables the power required for the movement of the drum (2) at the second rotational speed to be measured.

7. A household appliance (100) as in any one of the above claims, characterized by the control unit (9) which is configured to determine a secondary load value related to the laundry load in the drum (2) by processing the temperature data received from the first temperature sensor (7) and the second temperature sensor (8) within a certain time interval during a drying process wherein the heating unit (5) is active.

8. A household appliance (100) as in Claim 7, characterized by the control unit (9) which is configured to control the difference between the temperature data received from the first temperature sensor (7) and the temperature data received from the second temperature sensor (8) or the rate of change in the said temperature data during the drying process wherein the heating unit (5) is active, and to terminate the said drying process by deactivating the heating unit (5) upon reaching a target difference value or rate of change.

9. A household appliance (100) as in any one of the above claims, characterized by the second temperature sensor (8) which is positioned under the drum (2) so as to remain between the tub (3) and the drum (2) during the operation.

10. A household appliance (100) as in any one of the above claims, characterized by being a laundry dryer.

11. A household appliance (100) as in any one of Claims 1 to 9, characterized by being a laundry washer / dryer.

12. A control method for a household appliance (100) as in Claim 1, comprising the following steps in order: v. partially removing the moisture from the laundry by means of the rotational movement of the drum (2) at a first rotational speed of 600 rpm or above, vi. increasing the drum (2) speed to a second rotational speed, vii. transmitting the data regarding the amount of power required for the rotational movement of the drum (2) at the second rotational speed from a motor control unit (11) associated with the motor (4) to the control unit (9), and viii. determining a primary load value related to the laundry load in the drum (2) based on the data received by the control unit (9).

13. A control method as in Claim 12, comprising the following steps to be performed before the step (v) or during the step (v) in order i. Activating the heating unit (5) ii. Transmitting the temperature data received from the first temperature sensor (7) and the second temperature sensor (8) to the control unit (9) iii. Processing the received temperature information and deactivating the heating unit (5) by the control unit (9) when the difference and / or rate of change between the said values reaches a predetermined value iv. Determining a secondary load value related to the laundry load in the drum (2) based on the temperature data received by the control unit (9).

14. A control method as in Claim 12, comprising the following steps to be performed after the step (viii) in order: ix. grouping the primary load value determined in the step (viii) based on different load ranges and including the same in one of the predefined categories on the control unit, each of which is assigned different drying parameters x. drying the laundry in the drum (2) according to at least one of the parameters specifically defined for the category to which the primary load value is assigned, such as fan (52) speed, drum (2) speed, heater (51) operation duration, or heater (51) operation frequency.

15. A control method as in Claim 12, comprising the following steps to be performed after the step (viii) in order: ix. determining a category corresponding to the secondary load value determined in the step (iv) from among the categories predefined in the control unit according to different load ranges x. dividing the category determined in the step (ix) into predefined subcategories in the control unit according to different load ranges, each associated with different drying parameters, and classifying the primary load value determined in the step (viii) into one of these subcategories xi. drying the laundry in the drum (2) according to at least one of the parameters specifically defined for the category to which the primary load value is assigned, such as fan (52) speed, drum (2) speed, heater (51) operation duration, or heater (51) operation frequency.

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