Clothing dryer

Abstract

To provide a clothing dryer capable of detecting clogging of a drying filter based on a principle different from a conventional one.SOLUTION: A clothing dryer comprises: a drying chamber; a circulation air passage; a heating part to heat dry air; a drying filter provided in the circulation air passage; an exhaust mechanism that has an exhaust port and an opening / closing part and can discharge part of the dry air flowing in the circulation air passage to the outside of the circulation air passage; an operation processing part capable of executing a drying operation including an opening operation to open the exhaust port during a heating step; and a determination processing part which detects a relative temperature difference to a preset reference temperature and can execute determination processing to determine that clogging occurs in the drying filter when an increasing speed of the temperature difference after executing the opening operation does not become lower than a threshold.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] Conventionally, there has been a clothes dryer equipped with a circulation air duct. Such a clothes dryer heats the air flowing through the circulation air duct by a heating unit such as a condenser of a heat pump unit or an electric heater provided in the circulation air duct, and circulates the warm air generated by the heating back into the drying chamber again to dry the clothes in the drying chamber.

[0003] Since the clothes dryer stirs the clothes during drying, lint is generated from the clothes due to friction between the clothes and the drying air. In order to prevent this lint from clogging the circulation air duct and inhibiting drying, a drying filter for collecting lint is provided on the circulation air duct on the path from the drying chamber to the heating unit. However, when this drying filter is clogged with lint, the air volume of the drying air flowing through the circulation air duct decreases, and proper heating of the drying air is inhibited.

[0004] Therefore, in such a clothes dryer, it is required to frequently clean the drying filter, and the clogging of the drying filter is monitored so that it can be quickly cleaned even when clogging occurs. Conventionally, as a method for detecting clogging of the drying filter, for example, the temperature near the air inlet to the heating unit and the temperature near the air outlet from the heating unit are monitored, and it is determined that clogging has occurred in the drying filter when the temperature rises beyond a predetermined rate of increase or when the temperature difference between the two exceeds a predetermined value.

[0005] And in a conventional clothes dryer, for example, in anticipation of clogging of the drying filter, the drying operation time is set longer in advance, and control is performed such as shortening and ending the drying operation time when clogging of the drying filter does not occur.

Prior Art Documents

Patent Documents

[0006] Patent Document 1 Japanese Unexamined Patent Application Publication No. 2007-37716 Summary of the Invention Problems to be Solved by the Invention

[0007] However, in the above-described conventional configuration, the detection accuracy of clogging of the drying filter is not good. Therefore, even though there is no clogging, the drying operation is performed for a long set time, and as a result, there is a situation that it is likely to have an over-dried smell. Also, when the clogging of the drying filter cannot be correctly detected due to some influence, appropriate drying may not be performed, and the drying operation may end with the clothes in a damp state.

[0008] Therefore, there is provided a clothes dryer capable of detecting clogging of a drying filter based on a principle different from the conventional one. Means for Solving the Problems

[0009] The clothes dryer according to the embodiment has a drying chamber that can accommodate clothes and has a drying air inlet that is an inlet of the drying air used for drying the clothes and a drying air outlet that is an outlet of the drying air, a circulation air passage provided outside the drying chamber that connects the drying air inlet and the drying air outlet and is configured such that the drying air can circulate between the drying air outlet and the drying air inlet through the drying chamber, a heating unit provided in the circulation air passage that heats the drying air, a drying filter provided between the drying air outlet and the heating unit in the circulation air passage that collects lint contained in the drying air flowing through the circulation air passage, an exhaust port provided in the circulation air passage that communicates the inside and outside of the circulation air passage, an opening / closing unit that can open and close the exhaust port, an exhaust mechanism that can exhaust a part of the drying air flowing through the circulation air passage to the outside of the circulation air passage, a driving processing unit that can execute a drying operation that supplies the drying air heated by the heating unit into the drying chamber to dry the clothes in the drying chamber and includes an opening operation of opening the exhaust port during a heating process of raising the temperature of the clothes in the drying chamber, and a determination processing unit that can detect a relative temperature difference with respect to a preset reference temperature and determine that the drying filter is clogged when a rising speed of the temperature difference after the execution of the opening operation does not decrease below a threshold value.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0011] Hereinafter, a clothes dryer according to an embodiment will be described with reference to the drawings. The washing and drying machine 10 shown in FIGS. 1 and 2 is an application example of the clothes dryer of the present embodiment. The washing and drying machine 10 is a horizontal-axis or diagonal-axis type drum washing machine having a washing function and a drying function. Note that the clothes dryer of the present embodiment can also be applied to a so-called fully automatic vertical-axis washing machine having a washing function and a drying function. Further, the clothes dryer of the present embodiment can also be applied to, for example, a drying-only machine that does not have a washing function. In this specification, the air flowing into the washing and drying machine 10 mainly for drying clothes is referred to as drying air.

[0012] As shown in FIGS. 1 and 2, the washing and drying machine 10 includes an outer box 11, a door 12, an outer tub 13, a rotating tub 14, a motor 15, a drainage mechanism 16, a water supply mechanism 17, an operation panel 18, a blower device 19, a circulation air duct 20, a drying air generation device 30, and an exhaust mechanism 40. In this embodiment, the side of the outer box 11 where the door 12 is located, that is, the left side of the paper surface in FIG. 1, is defined as the front side of the washing and drying machine 10. The outer box 11 is formed in a rectangular hollow box shape by, for example, a stainless steel plate or the like, and constitutes the outer shell of the washing and drying machine 10. The outer box 11 has a clothing inlet / outlet 111 that communicates the inside and outside of the outer box 11 at the front side portion.

[0013] The door 12 is provided at the front part of the outer box 11 and is configured to be able to open and close the clothing inlet / outlet 111. The user can put clothes into or take out clothes from the rotating tub 14 through the clothing inlet / outlet 111 with the door 12 open.

[0014] The outer tub 13 is formed in a bottomed cylindrical shape with an open front side. In the case of this embodiment, the outer tub 13 can store water inside, and in this case, it functions as a water tank. The outer tub 13 has a drying air outlet 131 and a drying air inlet 132. The drying air outlet 131 is an outlet when drying air flows out from the outer tub 13. Also, the drying air inlet 132 is an inlet when drying air flows into the outer tub 13.

[0015] The drying air outlet 131 is, for example, at the upper front part of the peripheral wall constituting the cylindrical part of the outer tub 13, and is provided at a position away from the center in the left - right direction of the outer tub 13, that is, from the topmost part of the cylindrical outer peripheral surface of the outer tub 13 in the left - right direction. The drying air inlet 132 is provided, for example, at the bottom of the outer tub 13 at a position slightly above the center in the up - down direction of the bottom. The drying air outlet 131 and the drying air inlet 132 communicate the inside and outside of the outer tub 13.

[0016] The rotary tub 14 is formed in a bottomed cylindrical shape capable of accommodating clothing, and is rotatably accommodated inside the outer tub 13. The rotation axis of the rotary tub 14 coincides with the central axis of the outer tub 13. The rotary tub 14 has a plurality of communication holes 141. The communication holes 141 communicate the inside and the outside of the rotary tub 14. The communication holes 141 are formed over the entire circumferential wall constituting the cylindrical tubular portion of the rotary tub 14 and the bottom of the rotary tub 14. The communication holes 141 mainly function as water passage holes for water to enter and exit during the washing operation and the dehydration operation, and function as ventilation holes for air to enter and exit during the drying operation. The rotary tub 14, together with the outer tub 13, constitutes a drying chamber that accommodates clothing inside during the drying operation to dry the clothing.

[0017] The motor 15 is provided, for example, outside the bottom of the outer tub 13. The tip side of the rotation shaft 151 of the motor 15 protrudes inside the outer tub 13 and is connected to the rotary tub 14. As the motor 15, for example, an outer rotor type direct drive motor can be used. The motor 15 relatively rotates the rotary tub 14 with respect to the outer tub 13. In this case, the rotation shaft 151 of the motor 15, the central axis of the outer tub 13, and the rotation axis of the rotary tub 14 coincide with each other.

[0018] The drainage mechanism 16 has a function of discharging the water stored inside the outer tub 13 to the outside of the washing and drying machine 10. The drainage mechanism 16 includes a drain valve 161 and a drain pipe 162. The drain valve 161 is an electromagnetic drive type on-off valve for liquids. The drain valve 161 opens and closes a drainage path from inside the outer tub 13 to the outside through the drainage mechanism 16.

[0019] The water supply mechanism 17 is a mechanism for injecting water supplied from an external water source such as a water supply into the outer tub 13 as washing water for use in washing. The water supply mechanism 17 is provided, for example, above one side (left or right) of the outer tub 13 inside the outer box 11. The water supply mechanism 17 includes a water supply valve 171 and a water injection case 172. The water supply valve 171 is an electromagnetic drive type on-off valve for liquids and is connected to an external water source such as a water supply (not shown).

[0020] The water injection case 172 is configured to be able to accommodate a laundry treatment agent such as a detergent or a finishing agent inside. The water supply valve 171 opens and closes a water injection path leading from an external water source into the outer tub 13 via the water supply mechanism 17. When the water supply valve 171 is opened, water from the external water source is injected into the outer tub 13 via the water injection case 172. If a laundry treatment agent is stored in the water injection case 172 during the water injection, the laundry treatment agent in the water injection case 172 rides on the water flowing through the water injection case 172 and is poured into the outer tub 13. Note that the laundry dryer 10 does not necessarily have to be provided with the water injection case 172. That is, the laundry dryer 10 may be configured such that the user directly inputs a laundry treatment agent into the outer tub 13. Further, the laundry dryer 10 may be provided with an automatic dosing device that automatically doses a predetermined amount of laundry treatment agent into the outer tub 13 together with or in place of the water injection case 172.

[0021] The operation panel 18 has a function of receiving operation inputs related to the settings and operation of the laundry dryer 10 from the user and presenting information related to the settings and operation of the laundry dryer 10 to the user by means of display, voice, etc. The operation panel 18 can be configured, for example, as a touch panel display, or can be configured with touch switches, mechanical switches, etc. Further, the operation panel 18 can be configured by combining a touch panel display with touch switches, mechanical switches, etc. The operation panel 18 is provided, for example, at the front side portion of the upper surface of the outer box 11.

[0022] The circulation air path 20 is provided outside the outer tank 13 and the rotary tank 14 which are drying chambers, and is configured to be able to circulate the air inside the outer tank 13 and the rotary tank 14. The circulation air path 20 connects the drying air outlet 131 and the drying air inlet 132. The circulation air path 20 is configured such that the drying air inside the rotary tank 14 and the outer tank 13 flows from the drying air outlet 131 toward the drying air inlet 132 and can circulate between the rotary tank 14 and the outer tank 13. The circulation air path 20 takes in the air inside the outer tank 13 from the drying air outlet 131 into the circulation air path 20, heats the taken-in air to warm air by the action of the drying air generating device 30, and then supplies the warm air from the drying air inlet 132 into the outer tank 13. In this case, regarding the drying air flowing in the circulation air path 20, the drying air outlet 131 is the upstream side and the drying air inlet 132 is the downstream side.

[0023] The circulation air path 20 can be configured to include, for example, an exhaust duct 21, a filter box body 22, a connection duct 23, a heat exchange part 24, and an air supply duct 25. The exhaust duct 21, the filter box body 22, the connection duct 23, the heat exchange part 24, and the air supply duct 25 are arranged in order along the flow of the air flowing through the circulation air path 20.

[0024] The exhaust duct 21 is a duct that connects the drying air outlet 131 of the outer tank 13 and the filter box body 22. The exhaust duct 21 can be configured by, for example, a flexible hose or the like. The filter box body 22 can be configured by, for example, a resin-made, rigid container-shaped member. Inside the filter box body 22, for example, two drying filters 261 and 262 with different mesh sizes are detachably provided. Note that the drying filters 261 and 262 do not necessarily have to be composed of two drying filters, and may be composed of, for example, one drying filter or three or more drying filters.

[0025] The two drying filters 261 and 262 collect lint and foreign matters contained in the drying air flowing in the circulation air path 20. In this case, if the upstream side of the two drying filters 261 and 262 is the first drying filter 261 and the downstream side is the second drying filter 262, the downstream second drying filter 262 has a finer mesh than the upstream first drying filter 261.

[0026] The filter box body 22 has a part of the box-shaped upper surface opened so that, for example, two drying filters 261 and 262 can be inserted into and removed from the filter box body 22. In this case, an insertion / removal opening 112 is formed in the outer box 11. The insertion / removal opening 112 is formed through the outer box 11 and communicates with the inside of the filter box body 22. The two drying filters 261 and 262 are inserted into and removed from the filter box body 22 through the insertion / removal opening 112.

[0027] As shown in FIG. 1, the washing and drying machine 10 can be configured to further include a lid body 114. A first drying filter 261 is attached to the lid body 114, and is configured to be detachable from the filter box body 22 together with the first drying filter 261. When the lid body 114 is attached to the filter box body 22, it closes the insertion / removal opening 112 and is disposed on the same plane as the surface around the lid body 114 on the upper surface of the outer box 11, constituting the upper surface of the outer box 11, that is, the upper surface of the washing and drying machine 10.

[0028] The connection duct 23 is a duct that connects the filter box body 22 and the heat exchange unit 24. The heat exchange unit 24 is provided inside the lower part of the outer box 11 and below the outer tub 13 and the rotary tub 14. The air taken into the circulation air path 20 from the outer tub 13 is dehumidified and heated when passing through the heat exchange unit 24 to become dry warm air. The air supply duct 25 is a duct that connects the heat exchange unit 24 and the dry air inlet 132 of the outer tub 13.

[0029] The drying air generation device 30 mainly has the function of dehumidifying and heating the drying air flowing out from the outer tank 13 into the circulation air duct 20 to generate low-humidity and high-temperature drying air for drying clothes. In the case of this embodiment, the drying air generation device 30 can be configured by a heat pump unit equipped with a refrigeration cycle. As shown in FIG. 2 and the like, the drying air generation device 30 has an evaporator 31, a condenser 32, a compressor 33, an expansion valve 34, and the like. The evaporator 31 and the condenser 32 are provided in the heat exchange section 24. The evaporator 31 is provided upstream of the condenser 32 with respect to the air flow in the heat exchange section 24 during the drying operation. The evaporator 31 and the condenser 32, together with the compressor 33 provided outside the heat exchange section 24, constitute a heat pump unit, that is, a refrigeration cycle. The air passing through the heat exchange section 24 is cooled and dehumidified by the evaporator 31. Then, the air dehumidified by the evaporator 31 is heated by the condenser 32 to become warm air.

[0030] In this case, the evaporator 31 is provided on the circulation air duct 20 and functions as a dehumidifying section for dehumidifying the drying air. Further, the condenser 32 is provided on the circulation air duct 20 and functions as a heating section for heating the drying air. Note that the drying air generation device 30 is not limited to a heat pump unit, and may have, for example, an electric heater type configuration. In this case, the washing and drying machine 10 is provided with, for example, an electric heater and a water-cooled dehumidifying mechanism. The electric heater functions as a heating section for heating the drying air in the circulation air duct 20, similar to the condenser 32. Further, the water-cooled dehumidifying mechanism functions as a dehumidifying section for dehumidifying the drying air in the circulation air duct 20, similar to the evaporator 31.

[0031] The downstream side of the heat exchange unit 24 is connected to the dry air inlet 132 of the outer tank 13 by the air supply duct 25. The blower 19 can be provided, for example, at the connection part between the heat exchange unit 24 and the air supply duct 25. In the case of this embodiment, the blower 19 is provided on the downstream side of the condenser 32 and on the upstream side of the dry air inlet 132. The blower 19 can be composed of, for example, a sirocco fan. The blower 19 sucks in the air in the heat exchange unit 24 and discharges it to the air supply duct 25 side. Thereby, the warm air dehumidified and heated in the heat exchange unit 24 is supplied from the dry air inlet 132 into the outer tank 13 and further into the rotary tank 14 by the blowing action of the blower 19.

[0032] The exhaust mechanism 40 has an exhaust port 41 and an opening / closing part 42. The exhaust port 41 is provided in the middle of the circulation air path 20 and communicates the inside and outside of the circulation air path 20. The exhaust port 41 is composed of, for example, a hole formed through the circulation air path 20 or a gap between a plurality of members forming the circulation air path 20. The exhaust port 41 can be provided, for example, on the filter box body 22. The exhaust port 41 is formed, for example, through the upper surface of the filter box body 22 and communicates the inside and outside of the filter box body 22 constituting the circulation air path 20.

[0033] The exhaust mechanism 40 has a function of exhausting a part of the dry air flowing in the circulation air path 20 to the outside of the circulation air path 20. When the opening / closing part 42 is operated and the exhaust port 41 is opened, a part of the dry air flowing in the circulation air path 20 is exhausted to the outside of the circulation air path 20 through the exhaust port 41. In FIGS. 1 and 2, an example of the flow of the air circulating in the circulation air path 20 is indicated by a white arrow, and an example of the flow of the air discharged from the exhaust port 41 to the outside of the circulation air path 20 is indicated by a thin black arrow.

[0034] In this case, as shown in FIG. 1, an opening 113 is provided in the outer box 11. The opening 113 is formed through a part of the outer box 11 corresponding to the exhaust port 41, for example, the part closest to the exhaust port 41 in the outer box 11, and communicates the inside and outside of the outer box 11. The air exhausted from the exhaust port 41 to the outside of the circulation air path 20 is exhausted to the outside of the machine, that is, the outside of the outer box 11, through the opening 113.

[0035] The opening / closing part 42 has a function of actively opening and closing the exhaust port 41. The opening / closing part 42 can be provided, for example, on the filter housing 22. The opening / closing part 42 has an electric actuator such as a motor or a solenoid, and is configured to be able to open and close the exhaust port 41 based on a control signal. That is, the opening / closing part 42 has a function of switching between an open state in which the exhaust port 41 is opened and a part of the drying air in the circulation air passage 20 is exhausted from the exhaust port 41, and a closed state in which the exhaust port 41 is closed and a part of the drying air in the circulation air passage 20 is not exhausted from the exhaust port 41. In the present embodiment, operating the opening / closing part 42 to open the exhaust port 41 is referred to as an opening operation, and operating the opening / closing part 42 to close the exhaust port 41 is referred to as a closing operation.

[0036] Further, the circulation air passage 20 has an intake port 26. The intake port 26 is provided, for example, at a position between the evaporator 31 and the condenser 32 in the circulation air passage 20, and communicates the inside and the outside of the circulation air passage 20. The intake port 26 is constituted by, for example, a hole formed through the circulation air passage 20, a gap between a plurality of members forming the circulation air passage 20, or the like. When the drying air is exhausted from the exhaust port 41, the downstream side of the exhaust port 41 becomes a negative pressure. Due to this negative pressure, outside air in an amount substantially equal to the drying air exhausted from the exhaust port 41 is sucked into the circulation air passage 20 from the intake port 26.

[0037] The washing and drying machine 10 further includes an outside air temperature sensor 51, a drying chamber outlet temperature sensor 52, a drying air inlet temperature sensor 53, a compressor discharge temperature sensor 54, a condenser temperature sensor 55, an evaporator inlet temperature sensor 56, and an evaporator outlet temperature sensor 57. The outside air temperature sensor 51 detects the temperature outside the washing and drying machine 10, that is, the temperature of the room in which the washing and drying machine 10 is installed. As shown in FIG. 1, the outside air temperature sensor 51 is provided, for example, inside the outer box 11 at a position as far as possible from the outer tub 13 and the drying air generation device 30. That is, the outside air temperature sensor 51 is provided at a position where it is not easily affected by heat during the washing operation and the drying operation and where it is in contact with the outside air.

[0038] The drying chamber outlet temperature sensor 52 detects the temperature of the drying air that has flowed out from the outer tank 13 and the rotating tank 14 into the circulation air duct 20, before being affected by the heat of the evaporator 31 and the condenser 32. The drying chamber outlet temperature sensor 52 is provided, for example, near the drying air outlet 131 within the circulation air duct 20. That is, the drying chamber outlet temperature sensor 52 is provided within the circulation air duct 20 between the drying air outlet 131 and the evaporator 31. In the case of this embodiment, the drying chamber outlet temperature sensor 52 is provided between the drying filters 261, 262 and the evaporator 31.

[0039] The drying air inlet temperature sensor 53 detects the temperature of the drying air flowing from the circulation air duct 20 into the outer tank 13 and the rotating tank 14. That is, the drying air inlet temperature sensor 53 detects the temperature of the drying air that has been heated by the condenser 32 and before heat exchange with the clothing is performed. The drying air inlet temperature sensor 53 is provided, for example, near the drying air inlet 132 within the circulation air duct 20. In this case, the drying air inlet temperature sensor 53 is provided within the circulation air duct 20 between the condenser 32 and the drying air inlet 132. In the case of this embodiment, the drying air inlet temperature sensor 53 is provided between the blower device 19 and the drying air inlet 132.

[0040] The compressor discharge temperature sensor 54 is provided near the discharge side of the compressor 33 or on the refrigerant pipe connected to the discharge side of the compressor 33. The compressor discharge temperature sensor 54 detects the temperature on the discharge side of the compressor 33, that is, the temperature of the refrigerant discharged from the compressor 33. The condenser temperature sensor 55 is provided on the condenser 32 and detects the temperature of the condenser 32.

[0041] The evaporator inlet temperature sensor 56 is provided near the inlet of the evaporator 31 or on the refrigerant pipe connected to the inlet side of the evaporator 31. The evaporator inlet temperature sensor 56 detects the temperature of the refrigerant flowing into the evaporator 31. And the evaporator outlet temperature sensor 57 is provided near the outlet of the evaporator 31 or on the refrigerant pipe connected to the outlet side of the evaporator 31. The evaporator outlet temperature sensor 57 detects the temperature of the refrigerant flowing out from the evaporator 31.

[0042] Further, as shown in FIG. 3, the washing and drying machine 10 further includes a control device 60, an operation processing unit 61, and a determination processing unit 62. The control device 60 is mainly composed of a microcomputer having a CPU 601 and a storage area 602 such as a ROM, a RAM, and a nonvolatile memory. The control device 60 has a function of managing the operation of the entire washing and drying machine 10.

[0043] The motor 15, the drain valve 161, the water supply valve 171, the operation panel 18, the blower 19, the compressor 33, and the opening / closing unit 42 are electrically connected to the control device 60 and operate under the control of the control device 60. Further, the outside air temperature sensor 51, the drying chamber outlet temperature sensor 52, the drying air inlet temperature sensor 53, the compressor discharge temperature sensor 54, the condenser temperature sensor 55, the evaporator inlet temperature sensor 56, and the evaporator outlet temperature sensor 57 are electrically connected to the control device 60 and transmit their respective detection results to the control device 60.

[0044] The storage area 602 of the control device 60 stores, for example, programs for realizing the operation processing unit 61 and the determination processing unit 62. The control device 60 virtually realizes the operation processing unit 61 and the determination processing unit 62 by software by executing the above programs stored in the storage area 602 in the CPU 601. Note that the operation processing unit 61 and the determination processing unit 62 may be realized hardware-wise as an integrated circuit integrated with the control device 60.

[0045] The operation processing unit 61 can execute a washing operation, a drying operation, and a washing and drying operation by operating the motor 15, the drain valve 161, the water supply valve 171, the blower 19, and the compressor 33 as necessary. The user can select and execute a desired operation among the washing operation, the drying operation, and the washing and drying operation, for example, by operating the operation panel 18.

[0046] The washing operation is an operation for washing clothes, which is an operation of storing water in the outer tub 13 and washing the clothes in the rotating tub 14. The drying operation is an operation for drying clothes, which is an operation of supplying the drying air dehumidified and heated by the evaporator 31 and the condenser 32 into the outer tub 13 to dry the clothes in the rotating tub 14. And the washing-drying operation is an operation of sequentially executing the washing operation and the drying operation.

[0047] Next, the overall flow of the drying operation will be described with reference to FIG. 4. When the operation processing unit 61 executes the drying operation, for example, as shown in FIG. 4, it sequentially executes a weight detection step shown in step S11, a fabric detection step shown in step S12, a heating step shown in step S20, a drying detection step shown in step S30, and a cooling step shown in step S40. Note that the execution order of the weight detection step shown in step S11 and the fabric detection step shown in step S12 may be reversed.

[0048] The weight detection step of step S11 is a step of detecting the weight of the clothes put into the rotating tub 14. The fabric detection step of step S12 is a step of detecting the fabric of the clothes put into the rotating tub 14, specifically whether the main component is synthetic fiber or cotton. For the detection of weight and fabric, well-known technologies such as a weight sensor and a fabric sensor can be used.

[0049] The heating step of step S20 is a step of operating the blower 19 and the drying air generating device 30 to raise the temperature of the clothes in the rotating tub 14. Here, the heat that the drying air supplied into the rotating tub 14 gives to the clothes is used for the heat to raise the temperature of the clothes and the latent heat of vaporization to evaporate the moisture contained in the clothes. The heating step of step S20 is a period in the drying operation when the amount of heat used to raise the temperature of the clothes is larger than the amount of heat used for the latent heat of vaporization. That is, the heating step is a step of raising the temperature of the clothes.

[0050] In addition, in the drying detection step of step S30, in the drying operation, it is a period in which the amount of heat used for the heat of vaporization is approximately equal to the amount of heat used for the temperature rise of the clothing, that is, the period of constant rate drying. In this drying detection step, the temperature of the clothing in the rotary tank 14 remains almost constant. Therefore, for example, when the temperature difference between the temperature of the drying air flowing in from the drying air inlet 132 and the temperature of the drying air flowing out from the drying air outlet 131 shows an increasing trend, the operation processing unit 61 can determine that the heating step is continuing. The temperature difference in this case can be calculated, for example, by subtracting the detection result of the drying chamber outlet temperature sensor 52 from the detection result of the drying air inlet temperature sensor 53.

[0051] Then, based on the fact that the temperature difference between the drying air flowing into the outer tank 13 from the drying air inlet 132 and the drying air flowing out of the outer tank 13 from the drying air outlet 131 has changed from an increasing trend to a constant trend, the operation processing unit 61 determines that the heating step of step S20 has ended, and can then shift to the drying detection step of step S30.

[0052] After shifting to the drying detection step of step S30, the operation processing unit 61 determines whether or not the end condition of the drying detection step is satisfied in step S31. When the end condition of the drying detection step is not satisfied (NO in step S31), the operation processing unit 61 continues the drying detection step. The end condition of the drying detection step can be, for example, that a preset time has elapsed since shifting to the drying detection step of step S30.

[0053] Here, when the clothing is sufficiently dried and the moisture contained in the clothing decreases, the amount of heat used for the heat of vaporization decreases, so the amount of heat used for the temperature rise of the clothing increases, and as a result, the temperature of the clothing rises again. Therefore, as shown in FIG. 9, the end condition of the drying detection step can be, for example, that the temperature difference between the temperature of the drying air flowing into the outer tank 13 and the temperature of the drying air flowing out of the outer tank 13 has reached a preset value. And the end condition of this drying detection step can be set for each fabric quality, room temperature, and weight.

[0054] When the end condition of the drying detection process is satisfied (YES in step S31 of FIG. 4), the operation processing unit 61 ends the drying detection process, transfers the process to step S40, and executes the cooling process. In the cooling process of step S40, the compressor 33 is stopped to stop the dehumidification and heating of the drying air, and the blowing by the blower 19 is continued. Thereby, the clothes in the rotary tub 14 are cooled. The operation processing unit 61 executes the cooling process of step S40 for about several minutes, and then ends the drying operation.

[0055] Next, the details of the heating process in step S20 will be described with reference to FIGS. 5 and 6. FIG. 6 is a graph showing an example of the transition of the temperature difference Td in the heating process and the drying detection process. The temperature difference Td is a relative temperature difference with respect to a preset reference temperature T0. The reference temperature T0 can be, for example, the temperature of the drying air immediately after flowing out from the outer tank 13, that is, the temperature of the drying air in the circulation air passage 20 before being dehumidified by the evaporator 31. In this case, the reference temperature T0 is the detected temperature of the drying chamber outlet temperature sensor 52. And the temperature difference Td is the value obtained by subtracting the detected temperature of the drying chamber outlet temperature sensor 52 from the detected temperature of the drying air inlet temperature sensor 53.

[0056] Note that the temperature difference Td is not limited to the difference between the detected temperature of the drying air inlet temperature sensor 53 and the detected temperature of the drying chamber outlet temperature sensor 52. That is, when a heat pump unit is adopted as the heating method of the drying air, the temperature of the drying air flowing into the outer tank 13 also correlates with the temperature on the discharge side of the compressor 33, the temperature of the condenser 32, the temperature on the inlet side of the evaporator 31, or the temperature on the outlet side of the evaporator 31. Therefore, with the reference temperature T0 being 0°C, the temperature of the drying air flowing into the outer tank 13 may be configured to detect any one of the temperature on the discharge side of the compressor 33, the temperature of the condenser 32, the temperature on the inlet side of the evaporator 31, or the temperature on the outlet side of the evaporator 31 as the temperature difference Td. In this case, the temperature on the discharge side of the compressor 33 is the detected temperature of the compressor discharge temperature sensor 54. Also, the temperature of the condenser 32 is the detected temperature of the condenser temperature sensor 55. Also, the temperature on the inlet side of the evaporator 31 is the detected temperature of the evaporator inlet temperature sensor 56. And the temperature on the outlet side of the evaporator 31 is the detected temperature of the evaporator outlet temperature sensor 57.

[0057] In addition, in FIG. 6, A0 indicates the start point of the heating process. A1 indicates the point in time when the opening operation of the exhaust port 41 is executed. A2 indicates the point in time when the process shifts from the heating process to the drying detection process. And A3 indicates the point in time when the process shifts from the drying detection process to the cooling process.

[0058] When starting the heating process, the operation processing unit 61 operates the blower 19 and the compressor 33 in step S21 of FIG. 5 to start supplying the dehumidified and heated dry air into the outer tank 13.

[0059] Next, the operation processing unit 61 determines in step S22 whether the opening condition for opening the exhaust port 41 is satisfied. When the opening condition is not satisfied (NO in step S22), the operation processing unit 61 maintains the operations of the blower 19 and the compressor 33 and continues to supply the dry air into the outer tank 13. On the other hand, when the opening condition is satisfied (YES in step S22), the operation processing unit 61 shifts the process to step S23 and executes the opening operation to open the exhaust port 41. As a result, a part of the dry air containing a large amount of moisture is exhausted from the exhaust port 41 to the outside of the circulation air path 20.

[0060] Thus, the heating process includes the opening operation of operating the opening / closing part 42 to open the exhaust port 41. In other words, the operation processing unit 61 executes the opening operation of operating the opening / closing part 42 to open the exhaust port 41 during the heating process. Thereby, the start-up of the drying operation can be promoted.

[0061] That is, as the heating process progresses and the evaporation amount from the clothing increases, the humidity of the drying air flowing out from the outer tub 13 into the circulation air path 20 reaches a saturated state, and the dehumidification by the evaporator 31 cannot catch up. As a result, drying air that has not been sufficiently dehumidified is supplied into the outer tub 13, and as a result, the drying efficiency of the clothing decreases. Therefore, the operation processing unit 61 executes an opening operation, that is, opens the exhaust port 41, on the condition that, for example, a predetermined period has elapsed since the start of the drying detection process or the temperature of the compressor 33 has reached a predetermined temperature. Then, a part of the drying air with saturated humidity is exhausted from the exhaust port 41 to the outside of the circulation air path 20, and outside air with a lower humidity than the drying air in the circulation air path 20 is sucked in from the intake port 26. As a result, the humidity of the drying air in the circulation air path 20 decreases, and sufficiently dehumidified drying air can be supplied into the outer tub 13. As a result, a decrease in the drying efficiency of the clothing can be suppressed.

[0062] Further, when the drying air generating device 30 is configured by a heat pump unit, in the heating process of starting up the compressor 33, the compressor 33 is operated at a high frequency. However, when blockages occur in the drying filters 261 and 262, the air volume passing through the drying filters 261 and 262 decreases, and accordingly, the air volume flowing through the path from the drying air outlet 131 to the drying filters 261 and 262 in the circulation air path 20 decreases. Then, since the air volume flowing through the outer tub 13 and the rotary tub 14 also decreases, efficient heat exchange between the clothing and the drying air in the rotary tub 14 is hindered, and as a result, the temperature on the discharge side of the compressor 33 and the temperature of the condenser 32 in the circulation air path 20 or the refrigeration cycle abnormally increase. In this case, it is necessary to temporarily stop the compressor 33 and wait for the temperatures of each part of the refrigeration cycle to return to normal. Therefore, blockages in the drying filters 261 and 262 lead to the stop of the compressor 33, and as a result, the drying operation time is extended.

[0063] Therefore, the operation processing unit 61 executes an opening operation, that is, opens the exhaust port 41, on the condition that, for example, a predetermined period has elapsed since the start of the drying detection process, or the temperature of the compressor 33 has reached a predetermined temperature. As a result, the temperature of the drying air in the circulation air passage 20 decreases, the heat exchange efficiency in the condenser 32 improves, and as a result, abnormal overheating of each part of the refrigeration cycle is suppressed.

[0064] Also, as shown in FIG. 7, the execution condition of the opening operation, that is, the opening condition, can be, for example, that a predetermined time has elapsed since the start of the heating process, the temperature of the drying air supplied from the drying air inlet 132 to the outer tank 13 has reached a predetermined temperature, or the temperature of the compressor 33 has reached a predetermined temperature, etc. The opening condition of this exhaust port 41 may be configured to be set for each, for example, the weight and fabric quality of the clothes, or the outside air temperature, that is, the room temperature.

[0065] In the present embodiment, the determination processing unit 62 determines whether or not the drying filters 261 and 262 are clogged during the heating process. Specifically, when the process proceeds to step S24, the determination processing unit 62 executes a determination process. Here, when the drying filters 261 and 262 are not clogged, the air volume of the drying air is the same on the upstream side and the downstream side of the drying filters 261 and 262 in the circulation air passage 20. Therefore, by opening the exhaust port 41, the drying air is appropriately exhausted from the exhaust port 41, and the air outside the circulation air passage 20 is sucked from the intake port 26, and the drying air in the circulation air passage 20 and the outside air are appropriately exchanged. As a result, the temperature on the downstream side of the exhaust port 41 decreases. For this reason, as shown in FIG. 6, the inclination of the change in the temperature difference Td after the opening operation shown in the period from A1 to A2 is smaller than the inclination of the temperature difference Td before the opening operation shown in the period from A0 to A1.

[0066] Here, in the graph of the temperature difference Td shown by the solid line in FIG. 6, the positive slope indicates the rising speed of the temperature difference Td, and the negative slope indicates the falling speed of the temperature difference Td. In this case, if there is no clogging in the drying filters 261 and 262, the rising speed V2 of the temperature difference Td after the start operation shown in the period from A1 to A2 is smaller than the rising speed V1 of the temperature difference Td before the start operation shown in the period from A0 to A1.

[0067] On the contrary, when clogging occurs in the drying filters 261 and 262, the air volume passing through the drying filters 261 and 262 decreases. Therefore, in the circulation air passage 20, the air volume on the downstream side sandwiching the drying filters 261 and 262 is lower than the air volume on the upstream side. Then, even if the exhaust port 41 is opened, the air volume flowing out from the exhaust port 41 to the outside of the circulation air passage 20 decreases, and thus the amount of replacement between the drying air in the circulation air passage 20 and the outside air also decreases. For this reason, it becomes difficult for the temperature on the downstream side of the exhaust port 41 to decrease, and as a result, it becomes difficult for the slope of the temperature difference Td, that is, the rising speed V2, to become small. That is, when clogging occurs in the drying filters 261 and 262, the rising speed V2 of the temperature difference Td after the start operation shown in the period from A1 to A2 is less likely to be smaller than the rising speed V1 of the temperature difference Td before the start operation shown in the period from A0 to A1 compared to the case where there is no clogging in the drying filters 261 and 262.

[0068] The determination process is a process for determining the presence or absence of clogging in the drying filters 261 and 262 based on the change in the rising speed of the temperature difference Td. That is, the determination process is a process for determining that clogging has occurred in the drying filters 261 and 262 when the rising speed V2 of the temperature difference Td after the execution of the start operation shown from A1 to A2 in FIG. 6 does not decrease below the threshold value Vh.

[0069] As shown in FIG. 6, for example, the determination processing unit 62 can set the rising speed V1 of the temperature difference Td before the execution of the start operation to the threshold value Vh. In this case, as shown in FIG. 6, the determination processing unit 62 can set the periods H1 and H2 for acquiring the temperature difference Td used in the determination processing to about several minutes before and after the execution of the start operation, for example. The determination processing unit 62 acquires the temperature difference Td for at least several minutes before and after the execution of the start operation. The determination processing unit 62 calculates the rising speed V1 before the start operation and the rising speed V2 after the start operation from the acquired temperature difference Td, and sets the rising speed V1 before the start operation to the threshold value Vh. Then, when the rising speed V2 after the start operation is lower than the threshold value Vh, the determination processing unit 62 determines that no clogging has occurred in the drying filters 261 and 262. On the other hand, when the rising speed V2 after the start operation is not lower than the threshold value Vh, the determination processing unit 62 determines that clogging has occurred in the drying filters 261 and 262.

[0070] The determination processing unit 62 can also set a preset ratio to the threshold value Vh with respect to the rising speed V1 of the temperature difference Td before the execution of the start operation. For example, when 30% is set as the preset ratio, the determination processing unit 62 sets the value of 30% of the rising speed V1 of the temperature difference Td before the execution of the start operation as the threshold value Vh.

[0071] Further, the determination processing unit 62 may set a preset value before the execution of the drying operation to the threshold value Vh. In this case, the threshold value Vh is, for example, a value obtained experimentally in advance. Also, the determination processing unit 62 may set the threshold value Vh for each room temperature, weight of clothing, or fabric of clothing. In this case, as shown in FIG. 8, for example, the washing and drying machine 10 stores a table of the threshold value Vh in the storage area 602.

[0072] In the case of the example in FIG. 8, if the weight of the clothing and the room temperature are the same, the threshold value Vh is set to be smaller when the fabric is cotton rather than synthetic fiber. Also, if the fabric and the room temperature are the same, the threshold value Vh is set to be smaller as the weight decreases. And if the weight and the fabric of the clothing are the same, the threshold value Vh is set to be smaller as the room temperature increases.

[0073] When the determination process in step S24 is executed in the flow of FIG. 5, the operation processing unit 61 determines the result of the determination process in step S25. If the result of the determination process is that clogging has not occurred in the drying filters 261 and 262 (NO in step S25), the operation processing unit 61 transfers the process to step S27. On the other hand, if the result of the determination process is that clogging has occurred in the drying filters 261 and 262 (YES in step S25), the operation processing unit 61 transfers the process to step S26 and executes clogging countermeasure processing.

[0074] As a first example of the clogging countermeasure processing, a process of lowering the driving frequency of the compressor 33 can be considered. As in the first example, when clogging occurs in the drying filters 261 and 262, by lowering the driving frequency of the compressor 33, the rate of increase in the temperature of the compressor 33 can be moderated. Thereby, abnormal overheating in each part of the circulation air passage 20 and the refrigeration cycle is suppressed, so that the heating process can be continued without stopping the compressor 33. As a result, it is possible to suppress a significant extension of the drying operation time compared to the setting at the start of the operation.

[0075] Also, as a second example of the clogging countermeasure processing, a process of changing the end condition of the drying detection process in step S31 of FIG. 4 can be considered. When the end condition of the drying detection process is, for example, the elapsed time since the start of the heating process or the drying detection process, the operation processing unit 61 can change the end condition of the drying detection process by extending the elapsed time for determining the end. In this way, by extending the execution time of the drying detection process, it is possible to compensate for the decrease in the air volume due to clogging of the drying filters 261 and 262, and as a result, it is possible to suppress the damp drying of the clothes.

[0076] Also, when the end condition of the drying detection process is, for example, that the temperature difference Td has dropped to a predetermined temperature as shown in FIG. 9, the operation processing unit 61 can change the end condition of the drying detection process by changing the temperature that serves as the threshold for determining the end, as shown in FIG. 10. That is, the operation processing unit 61 can end the drying operation in a shorter time by using an end condition suitable when clogging has not occurred in the drying filters 261 and 262. Further, the operation processing unit 61 can suppress unthorough drying or the like by using an end condition suitable when clogging has occurred in the drying filters 261 and 262.

[0077] Next, the operation processing unit 61 transfers the process to step S27 and determines whether the end condition of the heating process is satisfied. The end condition of the heating process can be, for example, that the temperature difference Td has turned to a decreasing trend. Also, the end condition of the heating process can be, for example, that a preset time has elapsed since the start of the heating process, or that a preset time has elapsed since the opening operation was executed in step S23. When the end condition of the heating process is satisfied (YES in step S27), the operation processing unit 61 ends the heating process and transfers to the drying detection process of step S30 in FIG. 4.

[0078] According to the embodiment described above, the washing and drying machine 10, which is an example of a clothes dryer, includes an outer tub 13 and a rotary tub 14 that form a drying chamber capable of accommodating clothes, a circulation air passage 20, a condenser 32 that forms a heating unit, drying filters 261 and 262, an exhaust mechanism 40, an operation processing unit 61, and a determination processing unit 62.

[0079] The outer tub 13 has a drying air inlet 132 that is an inlet of the drying air used for drying clothes and a drying air outlet 131 that is an outlet of the drying air. The circulation air passage 20 is provided outside the outer tub 13 and the rotary tub 14. The circulation air passage 20 connects the drying air inlet 132 and the drying air outlet 131, and is configured such that the drying air can flow from the drying air outlet 131 toward the drying air inlet 132 and circulate between the outer tub 13 and the rotary tub 14.

[0080] The condenser 32 is provided in the circulation air duct 20 and heats the drying air. The drying filters 261 and 262 are provided in the circulation air duct 20 between the drying air outlet 131 and the condenser 32, and collect lint contained in the drying air flowing through the circulation air duct 20. The exhaust mechanism 40 is provided in the middle of the circulation air duct 20 and has an exhaust port 41 and an opening / closing part 42. The exhaust port 41 communicates the inside and the outside of the circulation air duct 20. The opening / closing part 42 is configured to be able to open and close the exhaust port 41. The exhaust mechanism 40 is configured to be able to exhaust a part of the drying air flowing through the circulation air duct 20 to the outside of the circulation air duct 20.

[0081] The operation processing unit 61 is capable of executing a drying operation. The drying operation is an operation of supplying the drying air heated by the condenser 32 into the outer tub 13 and drying the clothes in the rotary tub 14. The drying operation includes an opening operation of opening the exhaust port 41 during a heating step of raising the temperature of the clothes in the rotary tub 14.

[0082] And the determination processing unit 62 is capable of executing a determination process. The determination process is a process of detecting a relative temperature difference Td with respect to a preset reference temperature T0, and determining that the drying filters 261 and 262 are clogged when the rising rate of the temperature difference Td after the execution of the opening operation does not drop below a threshold value Vh.

[0083] According to this, the determination processing unit 62 can detect the clogging of the drying filters 261 and 262 by a detection principle different from the conventional one, that is, by monitoring the rising rate of the temperature difference Td after the opening operation during the heating step. And regarding the detection of the clogging of the drying filters 261 and 262, for example, by using together the detection method by the determination processing unit 62 of the present embodiment and the detection method of the conventional configuration, the clogging of the drying filters 261 and 262 can be detected with higher accuracy. And by improving the accuracy of the detection of the clogging, an appropriate drying operation suitable for the drying filters 261 and 262 can be executed. As a result, over-drying and half-drying caused by the clogging of the drying filters 261 and 262 can be suppressed, and thus the quality of the drying operation can be improved.

[0084] The determination processing unit 62 includes a process of setting the rising speed of the temperature difference Td before the execution of the opening operation to the threshold value Vh. According to this, when the rising speed of the temperature difference Td after the execution of the opening operation has no change at all from the rising speed of the temperature difference Td before the execution, that is, when the entire drying filters 261 and 262 are clogged, the determination processing unit 62 determines that clogging of the drying filters 261 and 262 has occurred. Thereby, it is possible to suppress an excessive determination of clogging of the drying filters 261 and 262.

[0085] The determination processing unit 62 includes a process of setting a preset ratio with respect to the rising speed of the temperature difference Td before the execution of the opening operation to the threshold value Vh. According to this, when the rising speed of the temperature difference Td after the execution of the opening operation has no change greater than a certain degree from the rising speed of the temperature difference Td before the execution, that is, when even a part of the drying filters 261 and 262 is clogged, the determination processing unit 62 determines that clogging of the drying filters 261 and 262 has occurred. Thereby, clogging of the drying filters 261 and 262 can be accurately detected.

[0086] The determination processing unit 62 includes a process of setting a value preset before the execution of the drying operation, for example, a value registered as a table as shown in FIG. 8, to the threshold value Vh. According to this, since the threshold value Vh of the determination processing is set experimentally in advance, complicated control or the like for setting the threshold value Vh becomes unnecessary.

[0087] Further, the determination processing unit 62 can set the threshold value Vh for each room temperature, weight of clothing, or fabric quality of clothing. According to this, since the threshold value Vh is set according to each of the room temperature, weight of clothing, or fabric quality of clothing, it is possible to realize a determination process suitable for the room temperature, weight of clothing, or fabric quality of clothing. As a result, clogging of the drying filters 261 and 262 can be detected more accurately.

[0088] Here, the exhaust mechanism 40 is provided between the drying filters 261 and 262 and the drying air inlet 132. Therefore, when the exhaust port 41 is opened, if there is no clogging in the drying filters 261 and 262, a part of the high-temperature drying air in the circulation air path 20 is exchanged with the low-temperature outside air, and as a result, the temperature of the drying air flowing into the outer tub 13 decreases. That is, the drying air flowing into the outer tub 13 is easily affected by the start operation and its temperature easily decreases. On the other hand, the drying air that has flowed into the outer tub 13 exchanges heat with the clothes containing a lot of moisture and its temperature decreases. For this reason, the drying air flowing out from the outer tub 13 is hardly affected by the start operation and its temperature hardly decreases.

[0089] Therefore, the determination processing unit 62 sets the temperature of the drying air flowing out from the outer tub 13 as the reference temperature T0. The determination processing unit 62 detects the temperature difference between the temperature of the drying air flowing into the outer tub 13 and the temperature of the drying air flowing out from the outer tub 13 as the temperature difference Td used in the determination processing. According to this, the temperature difference Td between the temperature of the drying air flowing into the outer tub 13 and the temperature of the drying air flowing out from the outer tub 13 can clarify the temperature influence due to the start operation, and as a result, the accuracy of the determination processing can be improved.

[0090] Here, when the drying air generation device 30 is configured by a heat pump unit having a compressor 33, a condenser 32, and an evaporator 31, and the heating unit is configured by the condenser 32, the temperature of the drying air flowing into the outer tub 13 correlates with the temperature on the discharge side of the compressor 33 and the temperature of the condenser 32.

[0091] Therefore, in the present embodiment, the determination processing unit 62 sets the reference temperature T0 to 0°C, and detects either one of the temperature on the discharge side of the compressor 33, that is, the detected temperature of the compressor discharge temperature sensor 54, or the temperature of the condenser 32, that is, the detected temperature of the condenser temperature sensor 55, or the temperature of the drying air flowing from the circulation air path 20 into the outer tub 13 and the rotary tub 14, that is, the detected temperature of the drying air inlet temperature sensor 53, as the temperature difference Td. Also by this, although it is inferior to the case where the temperature difference between the temperature of the drying air flowing into the outer tub 13 and the temperature of the drying air flowing out from the outer tub 13 is set as the temperature difference Td used in the determination processing, clogging of the drying filters 261 and 262 can be detected.

[0092] The above describes one embodiment of the present invention. However, this embodiment is presented as an example and is not intended to limit the scope of the invention. This novel embodiment 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 the equivalent scope thereof.

Explanation of Reference Numerals

[0093] 10... Clothes dryer, washing and drying machine, 20... Circulation air duct, 31... Evaporator, 131... Dry air outlet, 132... Dry air inlet, 32... Condenser, 33... Compressor, 40... Exhaust mechanism, 41... Exhaust port, 42... Opening / closing part, 61... Operation processing part, 62... Judgment processing part, T0... Reference temperature, Td... Temperature difference, Th... Threshold value, V1... Rising speed before start operation, V2... Rising speed after start operation, Vh... Threshold value

Claims

1. A drying chamber having an inlet for drying air, which is an inlet for drying air capable of accommodating clothing and used for drying clothing, and an outlet for drying air, which is an outlet for the drying air; A circulation air passage provided outside the drying chamber, connecting the drying air inlet and the drying air outlet, and configured such that the drying air can flow from the drying air outlet toward the drying air inlet and circulate between the drying chamber; A heating unit provided in the circulation air passage for heating the drying air; A drying filter provided between the drying air outlet and the heating unit in the circulation air passage for collecting lint contained in the drying air flowing through the circulation air passage; An exhaust port provided in the circulation air passage for communicating the inside and outside of the circulation air passage, and an opening / closing part capable of opening and closing the exhaust port, and an exhaust mechanism capable of exhausting a part of the drying air flowing through the circulation air passage to the outside of the circulation air passage; An operation for supplying the drying air heated by the heating unit into the drying chamber to dry the clothing in the drying chamber, and an operation processing unit capable of executing a drying operation including an opening operation of opening the exhaust port during a heating process of raising the temperature of the clothing in the drying chamber; A determination processing unit capable of detecting a relative temperature difference with respect to a preset reference temperature and determining that the drying filter is clogged when the rising speed of the temperature difference after the execution of the opening operation does not decrease below a threshold value. A clothes dryer.

2. The determination processing unit includes a process of setting the rising speed of the temperature difference before the execution of the opening operation to the threshold value. The clothes dryer according to Claim 1.

3. The determination processing unit includes a process of setting a preset ratio with respect to the rising speed of the temperature difference before the execution of the opening operation to the threshold value. The clothes dryer according to Claim 1.

4. The determination processing unit includes a process of setting a preset value before the execution of the drying operation to the threshold value. The clothes dryer according to claim 1.

5. The determination processing unit can set the threshold value for each of room temperature, the weight of the clothes, or the fabric of the clothes. The clothes dryer according to claim 1.

6. The determination processing unit uses the temperature of the drying air flowing out of the drying chamber as the reference temperature, and detects the temperature difference between the temperature of the drying air flowing into the drying chamber and the temperature of the drying air flowing out of the drying chamber. The clothes dryer according to claim 1.

7. The clothes dryer further includes a heat pump unit having a compressor, a condenser, and an evaporator. The heating unit is constituted by the condenser. The determination processing unit uses 0°C as the reference temperature, and detects any one of the temperature on the discharge side of the compressor, the temperature of the condenser, or the temperature of the drying air flowing into the drying chamber as the temperature difference. The clothes dryer according to claim 1.

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