Patent Grant
7891113
This application claims the benefit of Korean Patent Application No. 10-2007-0038073, filed on Apr. 18, 2007, which is hereby incorporated by reference as if fully set forth herein.
1. Field of the Invention
The present invention relates to a dryer, and more particularly to a clogging degree deciding method for a dryer, which can accurately determine a clogging degree of an air passage, even when there is an influence of external environments.
2. Discussion of the Related Art
Generally, a washing machine includes a body having a certain shape, a drum installed in the body, and a tub arranged to surround the drum. Wash water is collected in the tub. The washing machine also includes a drive motor for rotating the drum, a detergent box for supplying a detergent, a water supply pipe connected to the detergent box, to supply wash water alone or in a state of being mixed with the detergent supplied from the detergent box, and a drainage pipe for outwardly draining wash water used in a washing cycle. The washing machine further includes a pump and drainage hose, which are connected to an outer end of the drainage pipe, to forcibly drain the wash water.
The above-mentioned washing machine performs a washing operation using friction generated between laundry and wash water in the drum when the laundry falls by gravity during rotation of the drum. Recently, drum washing machines with various additional functions have been developed. For example, a drum washing machine, which has a drying function, not only to wash laundry, but also to dry laundry using hot air, has been developed.
Washing machines, which have a drying function as described above, are classified into a condensation type and an exhaustion type. In a condensation type washing machine, hot air generated from a heater is supplied to a drum by a blowing fan, to dry laundry contained in the drum. In this case, the air used to dry the laundry in the drum is in a hot and high-humid state. The air then flows to an air outlet communicating with a tub. At one side of the air outlet, a nozzle is arranged to inject cold water. By the nozzle, moisture is removed from the hot and high-humid air, to generate dry air, which is, in turn, supplied to the blowing fan.
In an exhaustion type washing machine, hot air generated from a heater and blown by a blowing fan flows to pass through laundry contained in a drum. The hot air is then exhausted to the outside of the washing machine through an exhaust port formed at one side of the washing machine. The exhaust port is connected to a bellows tube connected to a tub. The exhaust port also functions as a breath port when a baby or pet is confined in the washing machine.
In the washing machine, which has the above-mentioned exhaustion type drying function, lint may be produced from laundry during a drying operation. The lint is discharged to the outside of the washing machine through the exhaust port after circulating through the drum along with the hot air.
In order to prevent lint produced from laundry from being accumulated in the exhaust port, which functions to discharge lint to the outside of the washing machine, a structure capable of periodically collecting and removing lint is provided. For example, a lint filter is mounted in the exhaust port, in order to prevent the exhaust port from being clogged by lint when the washing machine is used for a prolonged period of time.
For the simplicity of description, the above-mentioned drying machines, which have a drying function, will be simply referred to as “dryers”.
In the above-mentioned conventional dryer, the exhaust port extends through an outer wall. However, the installer of the dryer does not perform a procedure for identifying the initial state of the exhaust port (namely, the state of the exhaust port in a formation stage thereof). For this reason, the determination as to whether or not the exhaust port satisfies minimum conditions for a desired operation of the dryer is simply made by the installer's determination.
Such a conventional dryer recommends for the user to clean the filter whenever the dryer is used. However, the user may frequently neglect the filter cleaning due to inconvenience and troublesome caused by the cleaning. In this case, the clogging degree of the filter increases as the drying operation is repeated. For this reason, an increase in drying time and an increase in power consumption may occur. When the clogging degree is excessive, lint may float in the drum without being collected by the filter, and may then be attached to the laundry and the inner surface of the dryer. In this case, the laundry may be contaminated by the lint. Furthermore, in the exhaustion type dryer, lint may be accumulated in the exhaust port functioning to exhaust air, which has been used to dry laundry, to the outside of the dryer, so that the lint may interfere with a flow of air. In this case, it is very difficult for the user to recognize such clogging of the exhaust port.
Furthermore, in the conventional dryer, it is possible to determine or identity only the clogging of the exhaust port. The conventional dryer cannot provide any information as to the current clogging degree of the exhaust port or air passage.
Accordingly, the present invention is directed to a clogging degree deciding method for a dryer that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a clogging degree deciding method for a dryer, which can more accurately determine the clogging degree of an air passage.
Another object of the present invention is to provide a clogging degree deciding method for a dryer, which can identify information as to the current clogging state of an air passage and a clogged portion of the air passage, and can display the information while providing the information to the user.
Another object of the present invention is to provide a clogging degree deciding method for a dryer, which can decide the clogging degree of the dryer in accordance with the execution of a drying operation or a variation in environment such as house-moving or cleaning.
Another object of the present invention is to provide a clogging degree deciding method for a dryer, which can accurately determine the clogging degree of an air passage even when the environment around the dryer varies, for example, even when power applied to the dryer varies.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a clogging degree deciding method for a dryer comprises: reading information as to clogging of an air passage; and displaying a clogging degree of an exhaust duct or a clogging degree of a filter in accordance with the read clogging information, wherein the clogging information comprises an ON/OFF duty ratio of a temperature control member, wherein the displaying comprise comparing a difference between two ON/Off duty ratios finally stored with a filter-clogging determination reference value, and determining the clogging degree of the filter, based on a result of the comparison.
The clogging degree deciding method may further comprise calculating the ON/OFF duty ratio of the temperature control member during a drying operation.
The clogging information may further comprise an initial clogging degree of the exhaust duct. The step of determining the clogging degree of the filter may comprise comparing the calculated ON/OFF duty ratio difference with a filter-clogging reference duty ratio corresponding to the initial clogging degree, and determining the clogging degree of the filter, based on a result of the comparison.
The clogging degree deciding method may further comprise determining the clogging degree of the exhaust duct.
The step of determining the clogging degree of the exhaust duct may be executed when there is no information stored as to clogging of the exhaust duct.
The step of determining the clogging degree of the exhaust duct may comprise calculating an average ON/OFF time of the temperature control member during a drying operation of the dryer, and primarily comparing the calculated average ON/OFF time with at least one of first and second reference values.
The step of determining the clogging degree of the exhaust duct may comprise calculating the ON/OFF duty ratio of the temperature control member, based on a result of the primary comparison, and secondarily comparing the calculated ON/OFF duty ratio with a clogging determination reference value for the exhaust duct.
In another aspect of the present invention, a clogging degree deciding method for a dryer comprises: staring a drying operation; primarily calculating an average ON/OFF time of a temperature control member during a drying operation; secondarily calculating an ON/OFF duty ratio of the temperature control member during the drying operation when the calculated ON/OFF time is within a predetermined range; primarily determining a clogging degree of an air passage, based on the calculated ON/OFF duty ratio; and secondarily determining the clogging degree of the air passage, based on the calculated ON/OFF time, when the calculated ON/OFF time is outside the predetermined range.
The clogging degree of the air passages may correspond to about a clogging degree of an exhaust duct.
The clogging degree deciding method may further comprise displaying the clogging degree of the air passage.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
Reference will now be made in detail to the preferred embodiments of the present invention associated with, for example, a dryer, examples of which are illustrated in the accompanying drawings. However, the scope of the present invention is not limited to the following embodiments and drawings. The scope of the present invention is limited only to the contents defined in the claims, which will be described later.
As shown in
A blowing fan 43 is arranged in one of the suction passage 20 and exhaust passage 40. The following description will be given only in conjunction with the case in which the blowing fan 43 is arranged in the exhaust passage 40.
As shown in
As shown in
A rear supporter 12 is mounted to a front surface of the back panel 7, to rotatably support a rear end of the drum 10. A communicating hole 13 is formed through the rear supporter 12, to communicate the suction passage 20 with an inlet of the drum 10, and thus enabling air emerging from the suction passage 20 to be introduced into the inlet of the drum 10.
As shown in
The suction passage 20 is defined by a suction duct having a lower end communicating with a rear end of the heater 30, and an upper end communicating with the communicating hole 13 of the rear supporter 12.
As shown in
As shown in
An air passage used in the present invention includes the suction passage 20, the inner space of the drum 10, the exhaust passage 40, and the external exhaust duct 50. Clogging of the air passage occurs mainly at the lint filter 41 of the exhaust passage 40 and in the external exhaust duct 50. The influence of the air flow interference caused by the clogging of the lint filter 40 in the exhaust passage 40 is relatively small, as compared to the influence of the air flow interference caused by the clogging of the external exhaust duct 50.
Hereinafter, operation of the exhaustion type dryer according to the illustrated embodiment of the present invention will be described.
The user closes the door 6 after loading laundry into the drum 10, and then operates the control panel 9, in order to operate the exhaustion type dryer. In accordance with the operation of the exhaustion type dryer, the heater 30 is turned on, and the motor 72 is driven.
When the heater 30 is in an ON state, it heats the interior thereof. As the motor 72 is driven, the blowing fan 43 and a belt 70 are rotated. In accordance with the rotation of the belt 70, the drum 10 is rotated. As a result, the laundry loaded in the drum 10 repeats operations of being raised by the lift 14, and then dropped.
During the rotation of the blowing fan 43, ambient air around the cabinet 1 is sucked into an air suction hole 7a formed through the back cover 7 by a blowing force generated in accordance with the rotation of the blowing fan 43. The sucked air is then guided between the cabinet 1 and the drum 10. The air introduced between the cabinet 1 and the drum 10 is introduced into the heater 30 which, in turn, heats the introduced air. As the air is heated, it comes into a state of high temperature and low humidity. Subsequently, the heated air is introduced into the drum 10 via the suction passage 20 and the communicating hole 13 of the rear supporter 12.
The hot and low-humid air introduced into the drum 10 comes into contact with the laundry as it flows forwardly in the drum 10, so that it comes into a high humid state. Thereafter, the air is introduced into the exhaust passage 40.
The air introduced into the exhaust passage 40 is guided by the exhaust pipe 46 such that it is outwardly exhausted through the external exhaust duct 50.
The first and second thermostats TS1 and TS2 function as controllers operating in accordance with temperature. The first and second thermostats TS1 and TS2 are mounted at one side of the heater 30 or in the vicinity of the heater 30. The first and second thermostats TS1 and TS2 respond to the temperature of the heater 30 or the temperature of air heated by the heater 30. Each of the first and second thermostats TS1 and TS2 is maintained in an ON state until it senses a predetermined overheating temperature. When the first or second thermostat TS1 or TS2 senses a temperature exceeding the predetermined overheating temperature, it is transited to an OFF state, thereby cutting off the supply of the commercial power to the heater 30. In particular, once the first thermostat TS1 is transited to an OFF state, it does not return to an ON state, in order to assist the second thermostat TS2. The first and second thermostats TS1 and TS2 are mounted to, for example, the suction passage 20 connected to the heater 30.
The switch SW is constituted by an element such as a relay. The switch SW is maintained in an ON state during a drying operation in accordance with an ON-control operation of the microcomputer 90, while being maintained in an OFF state in accordance with an OFF-control operation of the microcomputer 90.
The input unit 9a receives control commands input from the user in association with the drying operation, and applies the control commands to the microcomputer 90.
The display unit 9b displays the control commands input from the user in association with the drying operation, the drying operation progress, the residual drying time, the clogging degree of the air passage, the clogged position, etc. In the present invention, the air passage includes the suction passage 20, the inner space of the drum 10, the exhaust passage 40, and the external exhaust duct 50. In particular, the air passage may designate the lint filter 41 of the exhaust passage 40 and the external exhaust duct 50.
The detecting circuit 80 is connected to nodes N1 and N2, to detect whether or not current flows through a DC circuit including the heater 30, namely, whether or not power is supplied to the heater 30. For this determination, the detecting circuit 80 is connected to the nodes N1 and N2 by connecting lines 80a and 80b, respectively. The detecting circuit 80 is mounted on the control panel 9, on which the microcomputer 90 is also mounted. Accordingly, the connecting lines 80a and 80b extend along the inner space between the drum 10 and the cabinet body 3 or along the inner surface of the cabinet body 3.
In detail, the detecting circuit 80 detects whether or not power is supplied to the heater 30 in accordance with ON/OFF operations of the first and second thermostats TS1 and TS2 responding to the temperature of the heater 30 or the temperature of air heated by the heater 30. Of course, the supply of power to the heater 30 is also controlled by the switch SW. However, the switch SW operates under the control of the microcomputer 90. Accordingly, the microcomputer 90 determines whether or not power is supplied to the heater 30, based on a detect signal from the detecting circuit 80, in an ON state of the switch SW. When the switch SW is in an OFF state under the control of the microcomputer 90, the microcomputer does not take into consideration the detect signal from the detecting circuit 80.
The detecting circuit 80 sends a detect signal corresponding to a power supply or cutoff state to the microcomputer 90, so as to enable the microcomputer 90 to identify the power supply or cutoff state, based on the detect signal. Different from the circuit configuration shown in
As described above, the microcomputer 90 basically controls the heater 30, switch SW, and motor 72 in accordance with a command input from the user through the input unit 9a, and controls the blowing fan 43 in accordance with the control for the motor 72, for the execution of a desired drying operation. The microcomputer 90 is also equipped with a storage (not shown) to store a control algorithm for the above-described control operations. For the storage, for example, an EEPROM may be used.
The microcomputer 90 and detecting circuit 80 are mounted to a back surface of the above-described control panel 9.
The microcomputer 90 also determines information as to the power supply or cutoff carried out by the first and second thermostats TS1 and TS2 in accordance with the detect signal from the detecting circuit 80.
Where the commercial power has a voltage of, for example, AC 240V, the voltage difference between the node N1 and the node N2. When this voltage is directly applied to the photocoupler PC, the photocoupler PC may be damaged. To this end, the resistor R1 is used to reduce the input voltage to a several ten V.
When there is a voltage difference between the node N1 and the node N2, namely, when the first and second thermostats TS1 and TS2 turn on to enable power to be supplied to the heater 30, a voltage corresponding to the voltage difference is applied to the input terminals 11 and 12 of the photocoupler PC. Since the applied voltage is an AC voltage, a photodiode, which is included in the photocoupler PC, as a light emitter, periodically emits light in accordance with the cycle of the voltage. Accordingly, a transistor, which is also included in photocoupler PC, as a light receiver, is periodically turned on/off. As a result, a square wave is applied to the microcomputer 90. On the other hand, when there is no voltage difference between the node N1 and the node N2, namely, when the first and second thermostats TS1 and TS2 turn off to prevent power from being supplied to the heater 30, the input terminals 11 and 12 of the photocoupler PC are maintained at the same voltage level. The photodiode of the photocoupler PC does not emit light, so that the transistor of the photocoupler PC is maintained in an OFF state. As a result, a DC voltage waveform approximate to the reference voltage Vref is continuously applied to the microcomputer 90.
On the other hand, when the first and second thermostats TS1 and TS2 are in an OFF state, no power is supplied to the heater 30. Accordingly, the nodes N1 and N2 are maintained at the same voltage level, so that the photocoupler PC is maintained in an OFF state. As a result, a DC voltage (for example, a high signal) approximate to the reference voltage Vref is continuously applied to the microcomputer 90, as shown in
Thus, the microcomputer 90 can calculate the time, for which the power supply to the heater 30 is cut off in accordance with the OFF state of the first and second thermostats TS1 and TS2, based on the waveform of the DC voltage applied to the microcomputer 90.
In order to determine the clogging degree of the air passage, a determination method using a power supply ON/OFF duty ratio is used in accordance with the present invention. In the illustrated embodiment, one or either of an ON duty ratio (x′/y′) or an OFF duty ratio (z′/y′) may be used. The following description will be given in conjunction with the OFF duty ratio (z′/y′).
The OFF duty ratio of the case “R(2.0)” is 0.48 (ON duty ratio is 0.52), the OFF duty ratio of the case “R(2.3)” is 0.32 (ON duty ratio is 0.68), the OFF duty ratio of the case “R(2.625)” is 0.26 (ON duty ratio is 0.74), the OFF duty ratio of the case “R(2.88)” is 0.13 (ON duty ratio is 0.87), and the OFF duty ratio of the case “R(3.0)” is 0 (ON duty ratio is 1). That is, it can be seen that the OFF duty ratio increases as the diameter decreases. On the other hand, the ON duty ratio decreases. Thus, the microcomputer 90 can determine the clogging degree of the air passage (in particular, the clogging degree of the lint filter 41 or exhaust duct 50) by calculating the OFF duty ratio. Results of an experiment measuring the clogging degree of the air passage are described in the following Table 1.
The microcomputer 90 stores air passage clogging information acquired based on the above-described ON/OFF duty ratio. The storing operation is repeatedly carried out in accordance with the number of drying operations carried out in the dryer 1. In particular, when the dryer 1 is initially installed, or is re-installed due to house-moving or other reasons, the microcomputer 90 initially stores an initial clogging degree of the air passage, more accurately, an initial clogging degree of the exhaust duct 50, and additionally stores a clogging degree according to a subsequent drying operation whenever the drying operation is carried out. For example, the microcomputer 90 stores a value D0 as an initial clogging degree, and values D1, D2, . . . , Dn−1, and Dn as subsequent clogging degrees.
As shown in
The microcomputer 90 stores filter-clogging reference duty ratios respectively corresponding to a plurality of initial clogging degrees, in the form of a look-up table.
For example, if it is assumed that an ON duty ratio of more than B corresponds to a normal state of the air passage, namely, a non-clogged state of the air passage, an ON duty ratio of not less than A, but not more than B, corresponds to a medially-clogged state of the air passage, and an ON duty ratio of less than A corresponds to a severely-clogged state of the air passage, the clogging degree of the air passage may be erroneously determined in accordance with a variation in the applied voltage in the case of R(2.625).
For this reason, if fixed ON/OFF duty ratios as described in Table 1 are used as reference values, under the condition in which there is a variation in the applied voltage, it is difficult to accurately determine the clogging degree or clogging state (clogging progress) of the air passage. In order to solve this problem, characteristics shown in
As shown in
Of course, even when the average OFF time is used, there may be a range where the average OFF time is reduced even when the diameter decreases, in the case in which the diameter is not more than E. In the range of E or less, the air passage may have a non-constant diameter (clogging degree) even at the same average OFF time, as compared to the range of more than “E”. For this reason, the microcomputer 90 erroneously determines the diameter in the range of E or less, when the determination is made, only based on the average OFF time. For example, when the average OFF time is “F”, the clogging degree of the air passage may be determined to be a diameter “D” or a diameter “D′”.
Therefore, the microcomputer 90 should determine the clogging degree or clogging state of the air passage by simultaneously or sequentially using the ON/OFF duty ratio and average OFF time.
In detail, at step S11, the microcomputer 90 determines whether or not there is an initial clogging degree of the air passage detected and stored by the microcomputer 90. If there is a stored initial clogging degree of the air passage, the microcomputer 90 proceeds to step S12. If not, the microcomputer 90 proceeds to step S13.
At step S12, the microcomputer 90 determines whether or not the difference between the finally-stored two of the stored clogging degree D0 to Dn, namely, the clogging degrees Dn and Dn−1, is more than a filter-clogging determination reference value Dr. If the clogging degree difference is more than the filter-clogging determination reference value Dr, the microcomputer proceeds to a routine A. The difference between the clogging degrees Dn and Dn−1 means that the current clogging degree of the lint filter 41 is severer than the previous clogging degree. Accordingly, when difference between the clogging degrees Dn and Dn−1 is more than the filter-clogging determination reference value Dr, it is necessary to more accurately determine the clogging degree or clogging state of the lint filter 41. In this case, therefore, the microcomputer 90 proceeds to the routine A. The routine A will be described later in detail.
At step S13, the microcomputer 90 calculates an average OFF time of the temperature control member during the drying operation or after the completion of the drying operation. When it is determined that the calculated average OFF time is more than a first reference value G (
When it is determined at step S14 that the calculated average OFF time is more than a second reference value F, the microcomputer 90 proceeds to step S15. If not, the microcomputer 90 proceeds to step S18.
At step S15, the microcomputer 90 determines that the clogging degree of the air passage (exhaust duct 50) is severe because the calculated average OFF time is more than the second reference value F. Accordingly, the microcomputer 90 displays the clogging degree through the display unit 9b. That is, when the calculated average OFF time is more than the second reference value F, the microcomputer 90 determines that the clogging degree is severe, as shown in
At step S16, the microcomputer 90 uses the ON duty ratio of the temperature control member because, when the calculated average OFF time is not more than the first reference value G, there may be no or little clogging, as shown in
At step S17, the microcomputer 90 determines that the current clogging degree of the air passage is normal or low. In this case, the microcomputer 90 displays a normal or low clogging degree or clogging state through the display unit 9b.
At step S18, the microcomputer 90 uses the ON duty ratio of the temperature control member because, when the calculated average OFF time is not more than the second reference value F, there may be no or little clogging, as shown in
At step S19, the microcomputer 90 determines that the current clogging degree of the exhaust duct 50 corresponds to a diameter of not more than “D′”. That is, the microcomputer 90 determines that the clogging degree of the exhaust duct 50 is medium, and displays the results of the determination through the display unit 9b.
At step S20, the microcomputer 90 stores the clogging degree of the exhaust duct 50 determined through steps S13 to S19. This clogging degree is included in the above-described information as to the clogging of the air passage.
When various average OFF times and various ON/OFF duty ratios are used in the procedure shown in the above flow chart, it is possible to determine and display the clogging degree of the exhaust duct 50 at various levels.
In detail, at step S31, the microcomputer 90 reads the stored information as to the clogging of the air passage.
At step S32, the microcomputer 90 reads an initial clogging degree from the clogging information, and reads a filter-clogging reference duty ratio corresponding to the read initial clogging degree.
At step S33, the microcomputer 90 compares the difference between the initial clogging degree D0 and the current clogging degree Dn with the filter-clogging reference duty ratio. If the clogging degree difference is more than the filter-clogging reference duty ratio, the microcomputer 90 proceeds to step S34. If not, the microcomputer 90 proceeds to step S35.
At step S34, the microcomputer 90 determines that the lint filter 41 is in a clogged state, and displays the results of the determination through the display unit 9b.
At step S35, the microcomputer 90 determines that the lint filter is in a non-clogged state, namely, a normal state, and displays the results of the determination through the display unit 9b.
When various filter clogging reference duty ratios are used in the procedure shown in the above flow chart, it is possible to finely divide the clogging degree range of the lint filter, and thus to provide a more-accurately-determined clogging degree of the lint filter 41 to the user.
Although the present invention has been described in conjunction with the above-described embodiments and the accompanying drawings, it is not limited to such embodiments and drawings.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
As apparent from the above description, the present invention provides an effect capable of more accurately determining the clogging degree of an air passage.
The present invention also provides capable of identifying information as to the current clogging state of an air passage and a clogged portion of the air passage, and displaying the information while providing the information to the user.
The present invention also provides an effect capable of deciding the clogging degree of the dryer in accordance with the execution of a drying operation or a variation in environment such as house-moving or cleaning.
Also, the present invention provides an effect capable of accurately determining the clogging degree of an air passage even when the environment around the dryer varies, for example, even when power applied to the dryer varies.
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