Clothing dryer

Abstract

To provide a clothing dryer capable of performing highly accurate drying detection.SOLUTION: A clothing dryer comprises: a storage tank that has an air outlet and an air inlet and stores clothing; a circulation air passage connecting the air outlet and the air inlet; a heating device that generates warm air by heating air flowing in the circulation air passage; a humidity sensor to detect humidity of the air in the circulation air passage; and a control part capable of executing operation including a drying processing to dry the clothing in the storage tank by controlling the heating device. During operation, the control part suppresses the heating of the clothing in the storage tank by controlling the heating device, when a constant state in which humidity change quantity in a fixed time becomes a fixed quantity or less continues for a prescribed time, or when cumulative time of the constant state reaches the prescribed time.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] Embodiments of the present invention relate to a clothes dryer.

Background Art

[0002] For example, the washing and drying machine disclosed in Patent Document 1 is an example of an electric device having a drying function. The washing and drying machine of Patent Document 1 includes a humidity detection unit that detects the humidity of the gas sent out from the tub through the exhaust port, a temperature detection unit that detects the temperature of the gas sent out from the tub through the exhaust port, and a control unit. In Patent Document 1, after starting the heating and drying of the gas by the warm air supply unit, when the humidity detection unit detects a predetermined humidity and the temperature detection unit detects a predetermined temperature, the control unit controls the warm air supply unit to stop the heating and drying. Thereby, it is intended to make the finish of the object to be dried in an appropriate state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the drying operation, when the drying operation is started and heat is applied to the clothes, the moisture contained in the clothes begins to evaporate. However, as the drying operation progresses, the amount of moisture contained in the clothes decreases. Further, the humidity of the gas sent out from the tub through the exhaust port shows a high value at the start of evaporation of moisture from the clothes, but shows a low value at the end of drying. Therefore, it is conceivable to detect the drying of the clothes using the humidity.

[0005] By the way, in the conventional method of drying detection using the absolute value of humidity, for example, variations in humidity may occur depending on the weight and fabric quality of the clothes to be dried, and it may be difficult to perform drying detection with high accuracy. Therefore, there was room for improvement in terms of performing drying detection with high accuracy.

[0006] Therefore, a clothes dryer capable of performing high-precision drying detection is provided.

Means for Solving the Problems

[0007] The clothes dryer according to the embodiment has an exhaust port and an air supply port, a storage tank for storing clothes, a circulation air duct connecting the exhaust port and the air supply port, a heating device for heating the air flowing through the circulation air duct to generate warm air, a humidity sensor for detecting the humidity of the air in the circulation air duct, and a control unit capable of executing an operation including a drying process for controlling the heating device to dry the clothes in the storage tank. The control unit controls the heating device to suppress heating of the clothes in the storage tank when a certain state in which the change amount of the humidity in a certain period is equal to or less than a certain amount continues for a predetermined period or when the cumulative time of the certain state reaches the predetermined time during the operation.

Brief Description of the Drawings

[0008] [Figure 1] Cross-sectional view schematically showing an example of a clothes dryer according to the first embodiment [Figure 2] View schematically showing an example of a clothes dryer according to the first embodiment [Figure 3] Block diagram showing the electrical configuration of the clothes dryer according to the first embodiment [Figure 4] Flowchart showing an example of each process executed in the drying operation of the clothes dryer according to the first embodiment [Figure 5] View showing an example of the change over time of temperature and humidity in the drying process of the clothes dryer according to the first embodiment [Figure 6]FIG. 10 is a diagram showing an example of predetermined time information for each fabric type stored in a storage unit for the clothes dryer according to the second embodiment. [Figure 7] FIG. 10 is a diagram showing an example of weight rank and room temperature rank for a clothes dryer according to a second embodiment. [Figure 8] FIG. 10 is a diagram showing an example of the control of the exhaust damper in the clothes dryer according to the third embodiment. [Figure 9] FIG. 10 is a diagram showing an example of exhaust damper control information stored in a storage unit for a clothes dryer according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, clothes dryers according to a number of embodiments will be described with reference to the drawings. Note that substantially the same elements in the respective embodiments are designated by the same reference numerals, and descriptions thereof will be omitted.

[0010] (First embodiment) First, the first embodiment will be described with reference to FIGS. The clothes dryer 10 shown in FIG. 1 is a drum-type clothes dryer, either a horizontal-axis type in which the rotation axis of the rotary tub 14 is oriented horizontally or an inclined-axis type inclined downward toward the rear. The clothes dryer 10 has, for example, a washing function and a drying function, and is capable of performing a washing and drying operation including each of the steps of washing, rinsing, spin-drying, and drying. The clothes dryer is not limited to a drum-type clothes dryer, but may also be a vertical-axis type clothes dryer in which the rotation axis of the rotary tub is oriented vertically. The clothes dryer can also be configured without a washing function.

[0011] Clothes dryer 10 includes outer case 11, door 12, water tub 13, rotating tub 14, motor 15, drainage mechanism 16, water supply mechanism 17, drying mechanism 30, and exhaust mechanism 40. In Fig. 1, the side of clothes dryer 10 on which it is installed, i.e., the vertically lower side, is referred to as the lower side of clothes dryer 10, and the side opposite the installation surface, i.e., the vertically upper side, is referred to as the upper side of clothes dryer 10. The side of clothes dryer 10 in front of the user, i.e., the left side of the paper in Fig. 1, is referred to as the front side of clothes dryer 10, and the side opposite the user, i.e., the right side of the paper in Fig. 1, is referred to as the rear side of clothes dryer 10.

[0012] The outer box 11 is formed as a rectangular hollow box as a whole by a combination of, for example, a metal such as a stainless steel plate or a resin material. The outer box 11 constitutes the outer shell of the clothes dryer 10. The outer box 11 has a front opening 111 on the front side that communicates the inside and the outside of the outer box 11. The door 12 is provided on the front side of the outer box 11 and opens and closes the front opening 111. The user can take in and out clothes from the rotary drum 14 through the front opening 111 with the door 12 open. Both the water tank 13 and the rotary drum 14 are formed in a so-called bottomed cylindrical shape in which one axial side, that is, the front side, is open and the other side, that is, the rear side, has a bottom.

[0013] The water tank 13 can store water inside. The water tank 13 is provided inside the outer box 11 and is elastically supported by a suspension (not shown). As shown in FIGS. 1 and 2, the water tank 13 has an exhaust port 131 and an air supply port 132. The exhaust port 131 and the air supply port 132 communicate the inside and the outside of the water tank 13. The exhaust port 131 is for discharging the air inside the water tank 13. The exhaust port 131 is, for example, a portion near the upper front of the water tank 13 and is provided at a position away to the right with respect to the center in the left-right direction of the water tank 13. The air supply port 132 is for supplying air into the water tank 13. The air supply port 132 is, for example, the bottom of the water tank 13 and is provided at a portion slightly above the center in the vertical direction of the bottom.

[0014] The rotary drum 14 can accommodate clothes inside and is rotatably arranged inside the water tank 13. The rotary drum 14, together with the water tank 13, constitutes a storage tank that accommodates clothes inside during the drying operation and dries the clothes. The rotary drum 14 is rotationally driven by a motor 15. The rotary drum 14 has a plurality of holes 141. The plurality of holes 141 are formed almost entirely over the circumferential surface of the rotary drum 14 and function as water passage holes through which water enters and exits, for example, during the dehydration process, and function as ventilation holes through which air enters and exits during the drying process. Further, the rotary drum 14 has a plurality of baffles (not shown). The baffles have the function of stirring and lifting up the clothes accommodated inside the rotary drum 14.

[0015] The motor 15 is provided outside the bottom of the water tank 13. Although not shown in detail, the motor 15 is composed of, for example, a brushless direct drive motor whose rotation speed can be changed. The motor 15 is connected to the rotating tank 14 and has a function of rotationally driving the rotating tank 14 relative to the water tank 13. The motor shaft portion 151 of the motor 15, the central axis of the water tank 13, and the rotation axis of the rotating tank 14 overlap each other.

[0016] The drainage mechanism 16 has a function of discharging the water stored in the water tank 13 to the outside of the clothes dryer 10. As shown in FIGS. 1 and 2, the drainage mechanism 16 has a drain valve 161 and a drain hose 162. The drain valve 161 is configured to be electromagnetically opened and closed. One end of the drain hose 162 is connected to the drain valve 161, and the other end is drawn out to the outside of the clothes dryer 10. When the drain valve 161 is opened, the water stored in the water tank 13 is discharged to the outside of the clothes dryer 10 through the drain hose 162. The drain valve 161 opens and closes a drainage path for draining the water stored in the water tank 13 to the outside.

[0017] The water supply mechanism 17 has a function of supplying water from an external water source such as a water supply to the water tank 13. As shown in FIG. 2, the water supply mechanism 17 has a water supply valve 171 and a water injection case 172. The water supply valve 171 is configured to be electromagnetically opened and closed. The water supply valve 171 has a function of opening and closing a water supply path from an external water source to the water tank 13 via the water supply mechanism 17. The water injection case 172 is provided on the downstream side of the water supply valve 171. The water injection case 172 has a treatment agent case (not shown). The treatment agent case is configured to be able to accommodate, for example, the laundry treatment agent required for one laundry operation. That is, the water injection case 172 is configured to be able to accommodate the laundry treatment agent inside. When the laundry treatment agent is stored in the treatment agent case, the water supplied from the external water source flowing into the water injection case 172 and the laundry treatment agent are mixed in the water injection case 172 and then supplied into the water tank 13 and the rotating tank 14. Note that the clothes dryer 10 may be provided with an automatic feeding device that automatically feeds a predetermined amount of laundry treatment agent into the water tank 13.

[0018] The drying mechanism 30 has a function of supplying warm air into the water tank 13. The drying mechanism 30 has a circulation air path 50 and a heating device 60. The circulation air path 50 is located outside the water tank 13, one end of which is connected to the exhaust port 131, and the other end of which is connected to the air supply port 132. The circulation air path 50 connects the exhaust port 131 and the air supply port 132. The circulation air path 50 is for circulating and supplying air into the water tank 13. The circulation air path 50 takes in the air in the water tank 13 from the exhaust port 131, generates warm air through the heating device 60, and then supplies the warm air into the water tank 13 from the air supply port 132. In this case, looking at the air flowing in the circulation air path 50, the exhaust port 131 is the upstream side, and the air supply port 132 is the downstream side.

[0019] The circulation air path 50 can be configured to have, for example, an exhaust duct 51, a filter device 52, a connection duct 53, a heat exchange section 54, and an air supply duct 55. The exhaust duct 51 is configured by, for example, a bellows-shaped hose having flexibility. One end of the exhaust duct 51 is connected to the exhaust port 131, and the other end of the exhaust duct 51 is connected to the filter device 52. The exhaust duct 51 is, for example, a part for discharging the air in the water tank 13.

[0020] The filter device 52 is provided on the downstream side of the exhaust port 131, in this case on the circulation air path 50, and collects foreign matters such as lint and dust contained in the air flowing out from the exhaust port 131 and flowing in the circulation air path 50. The filter device 52 can be configured to have a filter device main body 521 and a filter 522. The filter device main body 521 can be configured by, for example, a resin-made container-shaped member with an open upper surface. The opening provided on the upper surface of the filter device main body 521 is opened and closed by a lid body (not shown). The filter 522 is detachably provided inside the filter device main body 521. The filter 522 collects foreign matters contained in the air flowing in the circulation air path 50.

[0021] The connection duct 53 is a duct that connects the filter device 52 and the heat exchange section 54. The heat exchange section 54 is, for example, on the back side of the clothes dryer 10 and is arranged near the bottom inside the outer box 11. The heat exchange section 54 is provided at an intermediate part of the circulation air passage 50. The air taken into the circulation air passage 50 from the water tank 13 and flowing through the connection duct 53 is dehumidified, heated, and becomes warm and dry air when passing through the heat exchange section 54. The air supply duct 55 is a duct that connects the heat exchange section 54 and the air supply port 132 of the water tank 13. The air supply duct 55 is, for example, a part that supplies air into the water tank 13.

[0022] The heating device 60 constitutes, for example, a heat pump mechanism, that is, a refrigeration cycle. The heating device 60 is provided in the middle of the circulation air passage 50. The heating device 60 can heat the air flowing through the circulation air passage 50 to generate warm air for drying the clothes in the rotary drum 14. The warm air is set to be, for example, about 60°C to 70°C. As shown in FIG. 2, the heating device 60 includes an evaporator 61, a condenser 62, a compressor 63, and an expansion valve 64. The evaporator 61 and the condenser 62 are provided inside the heat exchange section 54. The evaporator 61 cools and dehumidifies the air circulating in the circulation air passage 50. The condenser 62 heats the air flowing through the circulation air passage 50 to make warm air. The compressor 63 is provided outside the heat exchange section 54. The expansion valve 64 is for decompressing high-pressure liquid refrigerant so that it is easy to evaporate. Note that the heating device 60 may be a well-known heater-type mechanism instead of the configuration of the heat pump mechanism.

[0023] Also, the drying mechanism 30 has a blower device 65. The blower device 65 is constituted by, for example, a sirocco fan. The blower device 65 is provided in the middle of the circulation air passage 50 and has a function of supplying the air dehumidified and heated by the heating device 60 into the water tank 13 from the air supply port 132. The blower device 65 is provided, for example, between the heat exchange section 54 and the air supply duct 55.

[0024] The exhaust mechanism 40 has an opening 41 and an exhaust damper 42. The opening 41 is provided in the middle of the circulation air duct 50 and communicates the inside and the outside of the circulation air duct 50. The opening 41 discharges a part of the air in the circulation air duct 50 to the outside. The exhaust damper 42 has an actuator such as a motor or a solenoid, and is configured to be able to open and close the opening 41 based on a control signal. When the exhaust damper 42 is open, the opening 41 is open, while when the exhaust damper 42 is closed, the opening 41 is closed. That is, the exhaust damper 42 has a function of switching between an open state in which the opening 41 is open and a part of the air in the circulation air duct 50 is discharged from the opening 41, and a closed state in which the opening 41 is closed and a part of the air in the circulation air duct 50 is not discharged from the opening 41.

[0025] Further, as shown in FIG. 1, the outer box 11 is provided with a communication port 112. The communication port 112 is located at a portion of the outer box 11 corresponding to the opening 41 and communicates the inside and the outside of the outer box 11. The air discharged from the opening 41 to the outside of the circulation air duct 50 is discharged from the communication port 112 to the outside of the clothes dryer 10 as shown by the black arrow in FIG. 1.

[0026] The clothes dryer 10 includes a room temperature sensor 71, an outlet side temperature sensor 72, an inlet side temperature sensor 73, and a humidity sensor 74. The room temperature sensor 71 detects the room temperature t which is the temperature outside the circulation air duct 50 and the water tank 13, that is, the outside air temperature near where the clothes dryer 10 is installed. As shown in FIG. 1, the room temperature sensor 71 is located, for example, on the front side inside the outer box 11. The room temperature sensor 71 is provided at a position away from the water tank 13 and the heating device 60, and is provided at a position where it is less affected by the heat in the drying operation and is easily exposed to the outside air.

[0027] The outlet-side temperature sensor 72 detects the temperature of the air in the circulation air passage 50 before it is affected by the heat of the evaporator 61 and the condenser 62. In this case, the outlet-side temperature sensor 72 is located in the circulation air passage 50 on the downstream side of the filter device 52 and on the upstream side of the evaporator 61. The inlet-side temperature sensor 73 detects the temperature of the air in the circulation air passage 50 that has been heated by the condenser 62. In this case, the inlet-side temperature sensor 73 is located in the circulation air passage 50 on the downstream side of the blower device 65 and on the upstream side of the air supply port 132.

[0028] The humidity sensor 74 detects the humidity of the air in the circulation air passage 50 before it is affected by the heat of the evaporator 61 and the condenser 62. Humidity means relative humidity (%), and relative humidity (%) is the ratio of the amount of water vapor in the air at that time to the amount of saturated water vapor at a certain temperature. The humidity sensor 74 is located in the circulation air passage 50 on the downstream side of the filter device 52 and on the upstream side of the evaporator 61. In the present embodiment, the humidity sensor 74 is located in the vicinity of the outlet-side temperature sensor 72. By positioning the humidity sensor 74 on the downstream side of the filter device 52, it is possible to prevent foreign matter from accumulating on the humidity sensor 74.

[0029] Also, as shown in FIG. 3, the clothes dryer 10 includes a control unit 80 and a storage unit 81. The motor 15, the drain valve 161, the water supply valve 171, the compressor 63, the blower device 65, the exhaust damper 42, and the storage unit 81 are electrically connected to the control unit 80 and operate under the control of the control unit 80. The room temperature sensor 71, the outlet-side temperature sensor 72, the inlet-side temperature sensor 73, and the humidity sensor 74 are electrically connected to the control unit 80 and transmit their respective detection results to the control unit 80. The control unit 80 is mainly composed of, for example, a microcomputer having a storage area such as a CPU, a ROM, a RAM, and a rewritable flash memory. The control unit 80 controls the overall operation of the clothes dryer 10. The storage area of the control unit 80 stores a control program for controlling the clothes dryer 10 to execute the operation. Each process of the control unit 80 is realized by the CPU executing the control program.

[0030] The control unit 80 receives detection signals from various sensors 71, 72, 73, 74, etc., and based on a control program, controls the operations of the motor 15, drain valve 161, water supply valve 171, compressor 63, blower 65, and exhaust damper 42 to execute the operation. The storage unit 81 is composed of well-known storage media such as ROM, HDD, semiconductor memory, and magnetic disk, and stores various information. Note that the storage unit 81 can be configured by a predetermined area set in the storage area of the control unit 80, for example.

[0031] As shown in FIG. 3, the clothing dryer 10 further includes a weight detection unit 82 and a fabric detection unit 83. The control unit 80 virtually realizes the weight detection unit 82 and the fabric detection unit 83 by software by executing a control program in the CPU. Note that the control unit 80 may be realized by hardware such as an integrated circuit for the weight detection unit 18 and the fabric detection unit 83, or may be realized by a combination of software and hardware.

[0032] The weight detection unit 82 detects the weight W of the clothing accommodated in the rotary drum 14. The weight detection unit 82 can detect the load acting on the motor 15 by measuring, for example, the q-axis current in the motor 15, and measure the weight W of the clothing in the rotary drum 14 based on the load. The fabric detection unit 83 detects the fabric of the clothing accommodated in the rotary drum 14. The fabric detection unit 83 can detect the fabric of the clothing based on, for example, the water content absorbed by the clothing. For example, the fabric detection unit 83 can detect whether it is "cotton-based" indicating that the main body of the fabric of the clothing is cotton, or "chemical fiber-based" indicating that the main body of the fabric of the clothing is chemical fiber.

[0033] The control unit 80 can execute, for example, a drying operation. The drying operation is an operation aimed at drying clothes. An operation means that a plurality of different processes are executed in sequence. The control unit 80 may be configured to be able to execute not only the drying operation but also other types of operations such as a washing and drying operation aimed at washing and drying clothes. As shown in FIG. 4, the drying operation includes, for example, a weight detection step shown in step S11, a fabric quality detection step shown in step S12, and a drying step shown in step S13, which are performed in order.

[0034] The weight detection step of step S11 is a step of detecting the weight of the clothes in the rotary tub 14 by the weight detection unit 82. When executing the weight detection step, the control unit 80 operates the motor 15 to rotate the rotary tub 14 and detects the load acting on the motor 15, that is, the weight of the clothes. The fabric quality detection step of step S12 is a step of detecting the fabric quality of the clothes in the rotary tub 14 by the fabric quality detection unit 83. When executing the fabric quality detection step, the control unit 80 compares the weight of the clothes before and after water supply into the rotary tub 14 to detect the fabric quality of the clothes.

[0035] The drying step of step S13 includes a step of drying the clothes by supplying warm air into the water tank 13 and the rotary tub 14. When executing the drying step, the control unit 80 controls the operations of the heating device 60, in this case the compressor 63 and the blower 65, etc., based on the detection signals of the outlet-side temperature sensor 72, the inlet-side temperature sensor 73, and the humidity sensor 74, etc., to dry the clothes in the rotary tub 14.

[0036] Here, as shown in FIG. 5, the drying step transitions in the order of a heating period T1, a constant rate period T2, a falling rate period T3, and a blowing period T4. In FIG. 5, the graph exemplified by reference sign A1 shows the change over time of the measured value of the outlet-side temperature sensor 72. Also, in FIG. 5, the graph exemplified by reference sign A2 shows the change over time of the measured value of the inlet-side temperature sensor 73. Furthermore, in FIG. 5, the graph exemplified by reference sign A3 shows the change over time of the measured value of the humidity sensor 74.

[0037] The heating period T1 shown in FIG. 5 is a period for warming the clothes in the rotary tub 14. The heating period T1 is a period during which the temperature and humidity in the rotary tub 14 tend to increase after the drying process is started by operating the compressor 63 and the blower 65. The control unit 80 can determine that the heating period T1 has ended, for example, when the detected temperature of the inlet-side temperature sensor 73 reaches a predetermined temperature. The constant rate period T2 is a period during which moisture evaporates from the clothes in the rotary tub 14. During the constant rate period T2, the detected temperature of the inlet-side temperature sensor 73 changes in a constant trend. Also, during the constant rate period T2, the detected humidity of the humidity sensor 74 tends to decrease. The detected humidity of the humidity sensor 74 during the constant rate period T2 is lower than the detected humidity of the humidity sensor 74 during the heating period T1. The control unit 80 can determine that the constant rate period T2 has ended, for example, when the detected humidity of the humidity sensor 74 reaches a threshold value as shown by the arrow B1 in FIG. 5. Further, the control unit 80 may determine the end time of the constant rate period T2 based on the elapsed time since the transition to the constant rate period T2 or the detection results of the respective temperature sensors 72 and 73.

[0038] The falling rate period T3 is a period during which the amount of evaporated moisture from the clothes in the rotary tub 14 tends to decrease. During the falling rate period T3, the change in the detected humidity of the humidity sensor 74 changes gently. Here, as a result of intensive studies, the inventor of the present application has focused on the fact that the moisture evaporation from the clothes in the rotary tub 14 decreases during the falling rate period T3, and has found that the drying detection can be estimated by using the magnitude of the change amount of the detected humidity of the humidity sensor 74 and the time during which the change amount changes.

[0039] Therefore, in the present embodiment, as shown by arrow B2 in FIG. 5, when a certain state where the amount of change in humidity within a certain period of time, for example, within 1 minute, is a certain amount or less, for example, 1% or less, continues for a predetermined time Tp, for example, 3 minutes continuously, the control unit 80 controls the heating device 60 to suppress heating of the clothes in the rotary drum 14. In this case, when the certain state continues for the predetermined time Tp, the control unit 80 stops the compressor 63 to stop heating of the clothes in the rotary drum 14. As the amount of change, the absolute value of the difference in the detected humidity of the humidity sensor 74 before and after a certain period of time can be used. The predetermined time Tp is a condition for suppressing heating of the clothes in the rotary drum 14 and indicates the duration of the certain state.

[0040] Note that, as a mode of controlling the heating device 60 to suppress heating of the clothes in the rotary drum 14, it is not limited to the mode of stopping the driving of the compressor 63, and a mode of reducing the output of the compressor 63 to suppress heating of the clothes in the rotary drum 14 may also be used. Further, the control unit 80 may be configured to control the heating device 60 to suppress heating of the clothes in the rotary drum 14 not only when the certain state continues for the predetermined time Tp but also when the cumulative time of the certain state reaches the predetermined time Tp.

[0041] The control unit 80 can determine that, for example, when the certain state continues for the predetermined time Tp, the rate reduction period T3 has ended. Further, the control unit 80 may determine the end time of the rate reduction period T3 based on the elapsed time since the transition to the rate reduction period T3 or the detection results of the temperature sensors 72 and 73.

[0042] Here, when there are a large number of clothes to be dried in the rotary drum 14 or when the ambient temperature at the location where the clothes dryer 10 is set is low, etc., for example, the evaporation rate of the moisture contained in the clothes becomes slow or the time until the moisture evaporates becomes long, and drying may not proceed in the initial stage of the drying process. And in a state where drying does not proceed, the amount of change in humidity becomes small. For this reason, if there is no detection start condition for the certain state, there is a risk of erroneously detecting the certain state with the clothes in an undried state.

[0043] Therefore, in the present embodiment, as shown by the arrow C1 in FIG. 5, when the detected humidity of the humidity sensor 74 decreases from the detected humidity during the heating period T1 and reaches a set value, for example, 40%, the control unit 80 starts detecting a steady state. By providing such a detection start condition for the steady state, it is possible to prevent erroneously performing drying detection. Further, the control unit 80 may be configured to start detecting a steady state when the detected humidity of the humidity sensor 74 decreases and reaches the set value and the change amount of the detected humidity of the humidity sensor 74 for a certain period, for example, 1 minute, is equal to or less than a predetermined value, for example, 5%. Thereby, by considering the change amount of the detected humidity in addition to the specific value of the detected temperature of the humidity sensor 74 as the detection start condition for the steady state, it is possible to more reliably prevent false detection of drying. Furthermore, the control unit 80 can start detecting a steady state during the decreasing rate period T3. By starting detecting a steady state during the decreasing rate period T3 in which the amount of moisture evaporated from the clothing almost disappears, it is possible to efficiently perform drying detection.

[0044] The air blowing period T4 is a period for cooling the inside of the rotary tub 14 and the clothing inside the rotary tub 14. During the air blowing period T4, the control unit 80 operates the air blowing device 65 with the compressor 63 stopped to cool the inside of the rotary tub 14 and the clothing inside the rotary tub 14. The control unit 80 can determine the end time of the air blowing period T4 based on the elapsed time since the transition to the air blowing period T4 or the detection results of the temperature sensors 72 and 73.

[0045] According to the embodiment described above, the clothes dryer 10 includes a water tank 13, a rotary drum 14, a circulation air passage 50, a heating device 60, a humidity sensor 74, and a control unit 80. The water tank 13 has an exhaust port 131 and an air supply port 132. The rotary drum 14 accommodates clothes. The circulation air passage 50 connects the exhaust port 131 and the air supply port 132. The heating device 60 heats the air flowing in the circulation air passage 50 to generate warm air. The humidity sensor 74 detects the humidity of the air in the circulation air passage 50. The control unit 80 can execute an operation including a drying process of controlling the heating device 60 to dry the clothes in the rotary drum 14. Then, during the operation, when a certain state in which the amount of change in humidity over a certain period of time is equal to or less than a certain amount continues for a predetermined time Tp or when the cumulative time of the certain state reaches the predetermined time Tp, the control unit 80 controls the heating device 60 to suppress the heating of the clothes in the rotary drum 14.

[0046] According to this, during the execution of the operation of drying the clothes in the rotary drum 14, the end timing of drying the clothes can be determined with high accuracy based on the combination of the state of the amount of change in humidity and the elapsed time of the state. Thereby, highly accurate drying detection can be realized.

[0047] The control unit 80 starts detecting a certain state when the humidity reaches a set value. According to this, by determining the detection start condition of the certain state, it is possible to perform highly accurate drying detection while preventing the state where the clothes are not dried.

[0048] The control unit 80 starts detecting a certain state during a deceleration period T3 in which the amount of moisture evaporated from the clothes in the rotary drum 14 tends to decrease. According to this, in the deceleration period T3 in which the amount of moisture evaporated from the clothes hardly remains, the fluctuation of humidity is gentle. By starting the detection of a certain state during the deceleration period T3, it is possible to perform highly accurate drying detection while preventing the state where the clothes are not dried.

[0049] (Second Embodiment) The second embodiment will be described with reference to FIGS. 6 and 7. In this second embodiment, the control content executed by the control unit 80 is different from that of the first embodiment. In this second embodiment, as shown in FIGS. 6(a) and 6(b), in the storage unit 81, predetermined time information regarding a predetermined time Tp based on a combination of a weight rank and a room temperature rank is stored corresponding to the type of fabric, for example, cotton-based or chemical fiber-based. As shown in FIG. 7, the weight rank is set in a plurality of stages, in this case 8 stages, corresponding to the range of the weight of the clothing. For example, when the weight W of the clothing is less than 0.5 kg, it is rank 1, and when the weight W of the clothing is 0.5 kg or more and less than 1.0 kg, it is rank 2. The range of the weight of the clothing in each stage and the number of stages of the weight rank are not limited to this. As shown in FIG. 7, the room temperature rank is set in a plurality of stages, in this case 4 stages, corresponding to the range of the room temperature. For example, when the room temperature t is less than 10°C, it is rank 0, and when the room temperature t is 10°C or more and less than 13°C, it is rank 1. The range of the room temperature in each stage and the number of stages of the room temperature rank are not limited to this.

[0050] Then, based on the room temperature t detected by the room temperature sensor 71 before the start of the drying process, the weight W detected by the weight detection unit 82 in the weight detection process, and the fabric detected by the fabric detection unit 83 in the fabric detection process, the control unit 80 sets the predetermined time Tp. The predetermined time Tp is set shorter, for example, as the weight W of the clothing in the rotary tank 14 is smaller and the room temperature t is higher. Specifically, for example, when the room temperature t detected by the room temperature sensor 71 is "15°C", the weight W detected by the weight detection unit 82 is "4.0 kg", and the fabric detected by the fabric detection unit 83 is "cotton-based", the control unit 80 sets the predetermined time Tp to "5 minutes" based on the predetermined time information shown in FIG. 6(a).

[0051] According to such a second embodiment, the same operational effects as those of the first embodiment are achieved. In addition, since the change in humidity over time during operation is affected by the weight and fabric quality of the clothing, by setting a predetermined time Tp for dryness detection based on the weight and fabric quality of the clothing, dryness detection can be performed with higher accuracy. Note that the predetermined time information stored in the storage unit 81 can be provided corresponding to the type of operation, for example, a drying operation or a wash-dry operation, respectively.

[0052] (Third Embodiment) Next, the third embodiment will be described with reference to FIGS. 8 and 9. In this third embodiment, the control content executed in the control unit 80 is different from that in each of the above embodiments. In this third embodiment, the control unit 80 can control the opening and closing operation of the exhaust damper 42 after starting the detection of a steady state based on the room temperature t detected by the room temperature sensor 71 before the start of the drying process and the weight W detected by the weight detection unit 82 in the weight detection process.

[0053] In this case, as shown in FIG. 8, for example, when the exhaust damper 42 is open during the heating period T1 and the constant rate period T2, the control unit 80 closes the exhaust damper 42 when starting the detection of a steady state as the transition to the falling rate period T3 occurs. In this way, by closing the exhaust damper 42 to a closed state while detecting a steady state, disturbances such as the pressure loss in the circulation air path 50 can be suppressed, and the detection accuracy of the humidity by the humidity sensor 74 can be improved. Note that the control unit 80 is not limited to a configuration in which the exhaust damper 42 is completely closed with respect to the control of the opening and closing operation of the exhaust damper 42 after starting the detection of a steady state, and may control to adjust the opening degree of the exhaust damper 42.

[0054] In this embodiment, as shown in FIG. 9, the storage unit 81 stores exhaust damper control information regarding whether to execute control of the opening / closing operation of the exhaust damper 42 after starting detection of a steady state based on the combination of the weight rank and the room temperature rank. In FIG. 9, the portion indicated by "○" shows the combined portion of the weight rank and the room temperature rank in which control of the opening / closing operation of the exhaust damper 42 is executed after starting detection of a steady state. For example, for a weight rank of 6 or more corresponding to a category with a large weight due to a large amount of clothing in the rotary tub 14 or the like, in order to prioritize the drying efficiency of the clothing, it is preferable that the exhaust damper 42 be operated with the damper open. Therefore, for a weight rank of 6 or more, the exhaust damper 42 is maintained in an open state without changing the opening / closing operation of the exhaust damper 42 before and after starting detection of a steady state.

[0055] According to such a third embodiment, the same operational effects as those of the first embodiment are achieved. Also, during the period of detecting a steady state, in order to prioritize the drying efficiency, the operation can be continued with the exhaust damper 42 open, or in order to more accurately detect minute changes in humidity, the operation can be continued with the exhaust damper 42 closed. Such a determination can be made based on the weight W and the room temperature t. Thereby, it is possible to execute drying detection while suppressing a decrease in drying efficiency.

[0056] Note that the above-described embodiments can be combined with each other. Also, it is possible to extract and combine only the characteristic portions of two or more embodiments. As described above, a plurality of embodiments of the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0057] 10...Clothes dryer, 13...Water tank (receptacle), 131...Exhaust port, 132...Air supply port, 14...Rotating tank (receptacle), 50...Circulation air path, 60...Heating device, 74...Humidity sensor, 80...Control unit

Claims

1. A storage tank having an exhaust port and an air supply port for storing clothes, A circulation air duct connecting the exhaust port and the air supply port, A heating device that heats the air flowing through the circulation air duct to generate warm air, A humidity sensor that detects the humidity of the air in the circulation air duct, A control unit capable of executing an operation including a drying process of controlling the heating device to dry the clothes in the storage tank, During the operation, when a certain state in which the change amount of the humidity within a certain time is equal to or less than a certain amount continues for a predetermined time or when the cumulative time of the certain state reaches the predetermined time, the control unit controls the heating device to suppress heating of the clothes in the storage tank. A clothes dryer.

2. The control unit starts detecting the certain state when the humidity reaches a set value. The clothes dryer according to Claim 1.

3. The control unit starts detecting the certain state during a period of decreasing rate in which the amount of moisture evaporated from the clothes in the storage tank tends to decrease. The clothes dryer according to Claim 1.

4. A weight detection unit that detects the weight of the clothes stored in the storage tank, A fabric detection unit that detects the fabric of the clothes stored in the storage tank, The predetermined time is set based on the weight and the fabric. The clothes dryer according to Claim 1.

5. A weight detection unit that detects the weight of the clothes stored in the storage tank, A room temperature sensor that detects the room temperature near where the clothes dryer is installed, An opening for discharging a part of the air in the circulation air duct to the outside, An exhaust damper that opens and closes the opening, The control unit can control the opening and closing operation of the exhaust damper after starting to detect the certain state based on the weight and the room temperature. The clothes dryer according to Claim 2 or 3.

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