JP7486126B2 - Washing and drying machine - Google Patents

Description

This invention relates to a washer/dryer.

The washer-dryer described in the following Patent Document 1 includes an outer casing, a water tub arranged inside the outer casing, a rotating drum housed inside the water tub, and a dry air duct and a blower unit for supplying dry air to the inside of the rotating drum. The dry air duct includes an outlet duct and an inlet duct formed integrally with the water tub. The blower unit includes a connecting duct connected to the outlet duct, a blower fan connected to the connecting duct, a heater connecting the blower fan and the inlet duct, and a dry filter attached to a filter attachment part provided on the connecting duct. During the drying operation of the washer-dryer, in response to the driving of the blower fan, air in the water tub flows through the outlet duct and the connecting duct, is heated by the heater to become dry air, and flows from the inlet duct into the water tub to dry the laundry in the rotating drum. The dryer filter captures dust contained in the air flowing through the connecting duct.

The drying filter can be removed from an opening on the upper surface of the filter mounting section. A sound collecting section is provided near the filter mounting section to collect the sound of the dry air flowing through the connecting duct and obtain a sound signal. During drying operation with the dry filter attached to the filter mounting section, the dry air duct is sealed and the sound emitted by the blower fan is relatively quiet, so the noise level of the dry air flowing through the connecting duct is relatively low. On the other hand, during drying operation with the dry filter not attached to the filter mounting section, the air duct resistance is reduced in the connecting duct and the volume of the dry air increases, so the noise level of the dry air flowing through the connecting duct is relatively high. In the washer-dryer, the presence or absence of the dry filter attached to the filter mounting section is determined based on the strength of the sound signal collected by the sound collecting section, i.e., the difference in noise level.

JP 2014-42741 A

In the washer-dryer described in Patent Document 1, the sound collection unit for determining whether or not a drying filter is installed is expensive, so an increase in costs is unavoidable.

This invention was made against this background, and aims to provide a washer-dryer that can determine at low cost whether or not a filter for the drying operation is installed.

The present invention relates to a heat pump including a housing, a washing tub arranged in the housing and accommodating laundry, an air circulation path arranged in the housing and including an outlet and a return port connected to the washing tub, an air blower that circulates the air in the washing tub by taking it from the outlet into the air circulation path and returning it from the return port into the washing tub, a compressor that compresses a refrigerant, a heat exchanger arranged in the air circulation path and performing heat exchange between the refrigerant and the air in the air circulation path, and a refrigerant circulation path that circulates the refrigerant between the compressor and the heat exchanger, a filter arranged in the air circulation path and capturing foreign matter from the air in the air circulation path, and a refrigerant compressed by the compressor. The washer-dryer includes a refrigerant temperature measuring unit that measures the temperature of the refrigerant, a control unit that controls the air blower and the heat pump to execute a drying operation that dries the laundry in the washing tub, a first door that opens and closes a first attachment/detachment opening provided in the air circulation path, and a second door that opens and closes a second attachment/detachment opening provided in the housing, in which the filter is removable from the air circulation path to the outside of the housing through the first attachment/detachment opening and the second attachment/detachment opening, and in which the control unit determines that the filter is not in the air circulation path when the temperature measured by the refrigerant temperature measuring unit after a predetermined time has elapsed since the start of the drying operation or the degree of increase in the temperature is less than a predetermined threshold value.

The present invention is also characterized in that the heat exchanger includes a first heat exchanger that is heated by the refrigerant compressed by the compressor and a second heat exchanger that is cooled by the refrigerant that has passed through the first heat exchanger, the refrigerant circulation path includes a discharge path that guides the refrigerant compressed by the compressor to the first heat exchanger, and a return path that guides the refrigerant from the second heat exchanger to the compressor, and the temperature measured by the refrigerant temperature measuring unit is the temperature of the refrigerant flow path in the first heat exchanger or the temperature of the discharge path.

The present invention is also characterized in that the washer/dryer further includes an air temperature measuring unit that measures the temperature of the air in the washing tub, and the control unit determines that the filter is not in the air circulation path even if the temperature measured by the air temperature measuring unit after a predetermined time has elapsed since the start of the drying operation, or the degree of increase in the temperature, is less than a predetermined threshold.

The present invention is also characterized in that the washer-dryer further includes a notification unit that notifies the user that the filter is not in the air circulation path when the control unit determines that the filter is not in the air circulation path.

The present invention is also characterized in that the control unit extends the drying operation when it determines that the filter is not in the air circulation path.

According to the present invention, in the drying operation of the washer/dryer, the air in the washing tub is taken out from the outlet into the air circulation path and returned to the washing tub from the return port in response to the operation of the blower. The circulating air is heated by heat exchange with the heat exchanger of the heat pump in the drying circulation path to become hot air, which dries the laundry in the washing tub. A filter arranged in the air circulation path captures foreign matter from the air in the air circulation path.
A user can open the first and second doors to open the first opening of the air circulation path and the second opening of the housing, and remove the filter in the air circulation path from the first and second openings to the outside of the housing for maintenance. When the user returns the filter from the first and second openings to the air circulation path and closes the first and second doors, installation of the filter in the air circulation path is completed.
In a washer/dryer using a heat pump, when a drying operation is started with a filter attached to the air circulation path, the temperature of the refrigerant compressed by the compressor in the heat pump continues to rise, so that the temperature of the refrigerant after a predetermined time has elapsed since the start of the drying operation or the degree of increase in the temperature becomes equal to or exceeds a predetermined threshold value. In this way, in the washer/dryer, if the temperature of the refrigerant measured by the refrigerant temperature measuring unit after a predetermined time has elapsed since the start of the drying operation or the degree of increase in the temperature is less than a predetermined threshold value, the control unit determines that the filter is not present in the air circulation path. By focusing on the temperature of the refrigerant in the heat pump in this way, it is possible to determine at low cost whether a filter for the drying operation is attached or not without adopting an expensive configuration for detecting whether a filter is attached or not. The temperature of the refrigerant measured by the refrigerant temperature measuring unit may be the temperature of the refrigerant itself or the temperature of the flow path through which the refrigerant flows.

Furthermore, according to the present invention, the heat exchanger includes a first heat exchanger that is heated by refrigerant compressed by the compressor, and a second heat exchanger that is cooled by refrigerant that has passed through the first heat exchanger, and the refrigerant circulation path includes a discharge path that guides the refrigerant compressed by the compressor to the first heat exchanger, and a return path that guides the refrigerant from the second heat exchanger to the compressor. The temperature of the refrigerant flow path in the first heat exchanger and the temperature of the discharge path tend to continue to rise significantly when a drying operation is started with a filter attached to the air circulation path, so by focusing on these temperatures, it is possible to accurately determine whether a filter is attached or not.

Furthermore, according to the present invention, when a drying operation is started with a filter attached to the air circulation path in a washer-dryer, the temperature of the air in the washing tub continues to rise, so that the temperature of the air a predetermined time after the start of the drying operation, or the degree of rise in said temperature, exceeds a predetermined threshold. Therefore, in the washer-dryer, even if the temperature of the air measured by the air temperature measuring unit a predetermined time after the start of the drying operation, or the degree of rise in said temperature, is less than the predetermined threshold, the control unit determines that a filter is not in the air circulation path. In this way, by focusing on not only the temperature of the heat pump refrigerant but also the temperature of the air in the washing tub, it is possible to determine at low cost whether a filter is attached or not.

In addition, according to the present invention, in a washer-dryer, if the control unit determines that a filter is not present in the air circulation path, the notification unit notifies the user of this fact, thereby encouraging the user to attach a filter to the air circulation path.

In addition, according to the present invention, the control unit extends the drying operation when it determines that the filter is not in the air circulation path, so that even if the laundry in the washing tub is difficult to dry because the filter is not in the air circulation path, the laundry can be dried to the end.

1 is a schematic vertical sectional right side view of a washing/drying machine according to one embodiment of the present invention. 2 is a block diagram showing the electrical configuration of the washer/dryer; FIG. 4 is a time chart showing temperature changes over time at various measurement points during a drying operation of a washer/dryer with a filter attached. 10 is a time chart showing the change over time in temperature at each measurement point during a drying operation with no filter attached. 5 is a flowchart showing a filter detection process according to the first embodiment during a drying operation. 10 is a flowchart showing a filter detection process according to a second embodiment; 13 is a flowchart showing a filter detection process according to a third embodiment. 10 is a flowchart showing a drying operation.

The following describes in detail an embodiment of the present invention with reference to the drawings. FIG. 1 is a schematic right side view in vertical section of a washer/dryer 1 according to an embodiment of the present invention. The direction perpendicular to the plane of FIG. 1 is referred to as the left-right direction X of the washer/dryer 1, the left-right direction in FIG. 1 is referred to as the front-rear direction Y of the washer/dryer 1, and the up-down direction in FIG. 1 is referred to as the up-down direction Z of the washer/dryer 1. In the left-right direction X, the back side in the plane of FIG. 1 is referred to as the left side X1, and the front side in the plane of FIG. 1 is referred to as the right side X2. In the front-rear direction Y, the left side in FIG. 1 is referred to as the front side Y1, and the right side in FIG. 1 is referred to as the rear side Y2. In the up-down direction Z, the upper side is referred to as the upper side Z1, and the lower side is referred to as the lower side Z2.

The washer-dryer 1 includes a housing 2, a washing tub 3 arranged in the housing 2, a water supply channel 4 and a drain channel 5 connected to the washing tub 3, and a drain filter 6 that captures foreign matter from the water discharged from the washing tub 3 through the drain channel 5. The washing tub 3 includes an outer tub 7 and a drum 8 housed in the outer tub 7. Therefore, the washer-dryer 1 is a so-called drum-type washer-dryer. The washer-dryer 1 includes a motor 9 that rotates the drum 8, and a drying unit 10 that dries the laundry L housed in the drum 8.

The housing 2 is formed in a box shape. The housing 2 has a vertically extending front wall 2A, a top wall 2B extending horizontally from the upper end of the front wall 2A to the rear side Y2, and a bottom wall 2C extending horizontally from the lower end of the front wall 2A to the rear side Y2. An opening 2D that connects the inside and outside of the housing 2 is formed in the front wall 2A. A door 11 that opens and closes the opening 2D is provided in the front wall 2A.

The outer tub 7 is connected to the upper end of a shock absorber 12 that extends from the bottom wall 2C of the housing 2 to the upper side Z1. As a result, the entire washing tub 3, including the outer tub 7 and drum 8, is elastically supported by the bottom wall 2C via the shock absorber 12. The outer tub 7 has a cylindrical circumferential wall 7A centered on an axis J that extends in the front-rear direction Y along the horizontal direction H, a disk-shaped back wall 7B that closes the hollow portion of the circumferential wall 7A from the rear side Y2, and a ring-shaped front wall 7C that is connected to the front edge of the circumferential wall 7A.

The rear wall 7B is arranged vertically and has an annular outer peripheral portion 7D and a cylindrical central portion 7E that protrudes one step further toward the rear side Y2 than the outer peripheral portion 7D. A through hole 7F is formed in the center of the central portion 7E, penetrating the central portion 7E in the front-rear direction Y along the axis J. The front wall 7C has an annular first portion 7G that protrudes toward the axis J from the front end edge of the circumferential wall 7A, a cylindrical second portion 7H that protrudes toward the front side Y1 from the inner peripheral edge of the first portion 7G, and an annular third portion 7I that protrudes toward the axis J from the front end edge of the second portion 7H. An entrance 7J that communicates with the hollow portion of the circumferential wall 7A from the front side Y1 is formed inside the third portion 7I. The entrance 7J communicates with the opening 2D of the housing 2 from the rear side Y2 in opposition to the opening 2D.

The water supply passage 4 has one end (not shown) connected to a faucet (not shown) and the other end 4A connected to, for example, the central portion 7E of the rear wall 7B of the outer tub 7. When supplying water, water from the faucet is supplied from the water supply passage 4 into the outer tub 7. Water such as tap water or detergent water in which detergent is dissolved in tap water is stored in the outer tub 7. A water supply valve 13 that is opened and closed to start and stop water supply is provided midway along the water supply passage 4.

The drainage channel 5 is connected to the lower end of the outer tub 7, for example, the lower end of the first part 7G of the front wall 7C. Water in the outer tub 7 is discharged outside the machine through the drainage channel 5. A drainage valve 14 is provided midway along the drainage channel 5, which is opened and closed to start and stop drainage.

The drain filter 6 is provided upstream of the drain passage 5 and closer to the outer tank 7 than the drain valve 14. The front end of the drain filter 6 is exposed to the front side Y1 from the front wall 2A of the housing 2, so that a user can grasp the front end of the drain filter 6 to attach or detach the drain filter 6 to or from the housing 2. A known configuration can be used as the configuration of the drain filter 6.

The drum 8 is one size smaller than the outer tub 7. The drum 8 has a cylindrical circumferential wall 8A arranged coaxially with the circumferential wall 7A of the outer tub 7, a disk-shaped back wall 8B that closes the hollow portion of the circumferential wall 8A from the rear side Y2, and a ring-shaped annular wall 8C that protrudes from the front end edge of the circumferential wall 8A toward the axis J. At least the circumferential wall 8A of the drum 8 has a plurality of through holes 8D formed therein, and water in the outer tub 7 travels between the outer tub 7 and the drum 8 through the through holes 8D. Therefore, the water level in the outer tub 7 and the water level in the drum 8 are the same. A support shaft 15 extending to the rear side Y2 along the axis J is provided at the center of the back wall 8B of the drum 8. The rear end of the support shaft 15 is arranged on the rear side Y2 of the back wall 7B through the through hole 7F of the back wall 7B of the outer tub 7.

A port 8E is formed inside the annular wall 8C, which communicates with the hollow portion of the circumferential wall 8A from the front side Y1. The port 8E faces and communicates with the port 7J of the outer tub 7 and the opening 2D of the housing 2 from the rear side Y2. The port 7J and the port 8E, together with the opening 2D, are opened and closed together by the door 11. A user of the washer-dryer 1 places laundry L in and takes laundry L out of the drum 8 through the open opening 2D, the port 7J, and the port 8E.

The motor 9 is disk-shaped with approximately the same outer diameter as the central portion 7E of the rear wall 7B of the outer tub 7, and is disposed on the rear side Y2 of the central portion 7E within the housing 2 and fixed to the central portion 7E. The motor 9 is connected to a support shaft 15 provided on the drum 8. The driving force generated by the motor 9 is transmitted to the support shaft 15, and the drum 8 is rotated around the axis J together with the support shaft 15. A clutch mechanism (not shown) may be provided between the motor 9 and the support shaft 15 to transmit or cut off the driving force of the motor 9 to the support shaft 15.

The drying unit 10 includes an air circulation path 20 and an air blower 21 for circulating the air in the washing tub 3, a filter unit 22 for capturing foreign matter from the circulating air, a branch path 23 and a water injection valve 24 for maintaining the filter unit 22, and a heat pump 25 for heating and dehumidifying the circulating air.

The air circulation path 20 is a flow path arranged around the outer tank 7 within the housing 2. The air circulation path 20 has an intermediate portion 20A extending in the front-rear direction Y at a position higher than the outer tank 7, a rear portion 20B extending from the rear end of the intermediate portion 20A to the lower side Z2, and a front portion 20C extending from the front end of the intermediate portion 20A to the lower side Z2. An outlet 20D is formed at the front end of the lower end of the rear portion 20B. The outlet 20D is connected to a portion of the outer periphery 7D of the rear wall 7B of the outer tank 7 that is higher than the upper water level, and communicates with the inside of the outer tank 7 from the rear side Y2. A return port 20E is formed at the lower end of the front portion 20C. The return port 20E is connected to the upper end of the second part 7H of the front wall 7C of the outer tank 7, and communicates with the inside of the outer tank 7 from the upper side Z1. The opening to which the outlet 20D is connected in the outer periphery 7D is called the outlet 7K, and the opening to which the return port 20E is connected in the front wall 7C is called the inlet 7L.

The blower unit 21 is a blower fan including a rotating blade 21A arranged in an upstream region near the outlet 20D in the mid-way portion 20A of the air circulation path 20, and an electric motor 21B that rotates the rotating blade 21A. When the rotating blade 21A rotates, the air in the washing tub 3, i.e., the air in the outer tub 7 and the drum 8, is taken out from the outlet 20D, i.e., the outlet 7K, into the air circulation path 20, as shown by the thick dashed arrows, and then returned to the washing tub 3 from the return port 20E, i.e., the inlet 7L. This causes the air in the washing tub 3 to circulate, flowing sequentially through the washing tub 3 and the air circulation path 20.

The filter unit 22 is disposed in the upstream region of the air circulation path 20 closer to the outlet 20D than the rotary vanes 21A, specifically in the rear portion 20B. The filter unit 22 includes one or more filters F1. The filter F1 is a dry filter composed of a mesh sheet and a frame supporting the mesh sheet. The filter F1 is disposed in a vertically extending position at a position where the air flowing through the air circulation path 20 passes through. When multiple filters F1 are provided, these filters F1 are disposed overlapping in the air flow direction in the air circulation path 20. When the air taken out from the outlet 20D for circulation and flowing through the air circulation path 20 passes through the filter F1, foreign matter such as lint contained in the air is captured by the filter F1.

The branch passage 23 branches off from the upstream part of the water supply passage 4 closer to the faucet than the water supply valve 13, and is connected to the filter unit 22. The water inlet valve 24 is provided in the branch passage 23, and is opened and closed to start and stop water inlet to the filter F1 of the filter unit 22. When the water inlet valve 24 is opened, water from the water supply passage 4 is supplied to the filter unit 22 through the branch passage 23, and is poured onto the filter F1 from the upper side Z1. As a result, the foreign matter captured by the filter F1 peels off from the filter F1 and falls from the outlet 20D of the air circulation passage 20 into the outer tub 7, where it is captured by the drain filter 6. The foreign matter captured by the drain filter 6 is removed when the user removes the drain filter 6 at an appropriate time for maintenance.

The heat pump 25 includes a compressor 26 that compresses the refrigerant, a heat exchanger 27 that exchanges heat between the refrigerant and the air in the air circulation path 20, and a refrigerant circulation path 28 that circulates the refrigerant between the compressor 26 and the heat exchanger 27.

A known electric compressor can be used as the compressor 26. The compressor 26 is, for example, positioned lower than the axis J, which is the axis of rotation of the drum 8, and is fixed to the bottom wall 2C of the housing 2.

The heat exchanger 27 is disposed in the mid-way portion 20A of the air circulation path 20 downstream closer to the return port 20E than the rotary vanes 21A of the blower section 21, specifically in the front side Y1 region. The heat exchanger 27 includes a first heat exchanger 27A which is a condenser on the heating side, a second heat exchanger 27B which is an evaporator on the cooling side, and a capillary tube 27C which connects the first heat exchanger 27A and the second heat exchanger 27B.

In this embodiment, the first heat exchanger 27A is disposed downstream of the second heat exchanger 27B in the intermediate portion 20A, i.e., on the front side Y1. The first heat exchanger 27A is provided with a plurality of heat dissipation fins 27D, and the second heat exchanger 27B is provided with a plurality of cooling fins 27E. A refrigerant flow path 27F is provided inside the first heat exchanger 27A, and a refrigerant flow path 27G is provided inside the second heat exchanger 27B. Each of the flow paths 27F and 27G is a pipe made of a metal such as aluminum. The plurality of heat dissipation fins 27D are disposed around the flow path 27F. The plurality of cooling fins 27E are disposed around the flow path 27G. The capillary tube 27C connects the flow paths 27F and 27G.

The refrigerant circulation path 28 is composed of metal pipes such as aluminum, and connects the compressor 26 and the heat exchanger 27. The refrigerant circulation path 28 is a circulation flow path that returns the refrigerant to the compressor 26 again after taking out the refrigerant from the compressor 26 via the heat exchanger 27. The refrigerant circulation path 28 includes a discharge path 28A that guides the refrigerant compressed by the compressor 26 to a flow path 27F in the first heat exchanger 27A. The refrigerant circulation path 28 further includes a return path 28B that guides the refrigerant that has flowed from the first heat exchanger 27A through the capillary tube 27C and through the flow path 27G of the second heat exchanger 27B from the second heat exchanger 27B to the compressor 26. The flow path 27F may be considered as part of the discharge path 28A, and the flow path 27G may be considered as part of the return path 28B.

The washer/dryer 1 further includes a control unit 30 configured by a board equipped with a microcomputer with a built-in timer. Electrical components such as the motor 9, the drying unit 10, the water supply valve 13, the drain valve 14, and the water injection valve 24 are electrically connected to the control unit 30 (see also FIG. 2). The control unit 30 executes the washing/drying operation by controlling the operation of these electrical components. The washing/drying operation includes a washing process, a rinsing process, a spin-drying process, and a drying process. The drying process may be executed separately from the washing/drying operation as a standalone drying operation. In the following explanation, the drying process and the drying operation are the same.

Prior to the start of the washing process, detergent is poured into the drum 8. During the washing process, the control unit 30 closes the drain valve 14, opens the water supply valve 13 for a predetermined time to supply water to the outer tub 7 and drum 8, and then rotates the drum 8 using the motor 9. This beats the laundry L in the drum 8 to wash it. In beating, the laundry L is repeatedly tumbling, in which it is lifted to a certain extent and then falls naturally to the water surface. Dirt is removed from the laundry L by the impact of the tumbling and the detergent components contained in the detergent water accumulated in the drum 8. After a predetermined time has elapsed since the start of tumbling, the control unit 30 opens the drain valve 14 to drain the water, and the washing process ends.

In the rinsing process, the control unit 30 closes the drain valve 14, opens the water supply valve 13 for a predetermined time to supply water to the outer tub 7 and drum 8, and then rotates the drum 8 with the motor 9. Then, the tumbling described above is repeated, so that the laundry L is rinsed with tap water in the drum 8. When the control unit 30 drains the water after a predetermined time has elapsed since the start of tumbling, the rinsing process ends. The rinsing process may be repeated multiple times. In the spin-drying process, the control unit 30 rotates the drum 8 for spin-drying with the drain valve 14 open. The laundry L in the drum 8 is spin-dryed by the centrifugal force generated by the spin-drying rotation of the drum 8. Water seeping out of the laundry L due to spin-drying is discharged from the drain 5 to the outside of the machine. The spin-drying process may be performed not only after the rinsing process, but also after the washing process.

In the drying process, the control unit 30 operates the blower unit 21 and the compressor 26 of the heat pump 25 to generate hot air, which is circulated between the drum 8 and the air circulation path 20 and supplied to the laundry L in the drum 8. Specifically, in the heat pump 25, the refrigerant is compressed by the compressor 26 to become high temperature and high pressure, and then dissipates heat when passing through the flow path 27F in the first heat exchanger 27A via the discharge path 28A. In the first heat exchanger 27A, the heat dissipation fins 27D are heated and become high temperature due to the heat dissipation of the refrigerant passing through the flow path 27F. The refrigerant that has passed through the first heat exchanger 27A is reduced in pressure when passing through the capillary tube 27C, and then cools the cooling fins 27E when passing through the flow path 27G in the second heat exchanger 27B.

The air in the air circulation path 20 during the drying process is dehumidified as it passes around the cooling fins 27E of the second heat exchanger 27B in the air circulation path 20. The dehumidified air is heated as it passes around the heat dissipation fins 27D of the first heat exchanger 27A, and becomes hot air. In other words, the air in the air circulation path 20 becomes hot air through heat exchange with the refrigerant flowing through the first heat exchanger 27A. This hot air flows into the outer tub 7 from the inlet 7L of the outer tub 7 and is supplied to the laundry L in the drum 8, thereby drying the laundry L. At this time, the control unit 30 may operate the motor 9 to rotate the drum 8. This allows the laundry L to be evenly exposed to hot air.

During the drying process, foreign matter such as lint is carried along by the hot air, but as described above, it is captured by the filter F1 of the filter unit 22. At an appropriate timing during or after the drying process, the control unit 30 opens the water inlet valve 24 to inject water into the filter F1 as a maintenance process, thereby removing the foreign matter from the filter F1.

The washer-dryer 1 further includes a filter F2 for capturing foreign matter that the filter F1 has not captured in the air circulation path 20. There may be one or more filters F2. Like the filter F1, the filter F2 is a drying filter composed of a mesh sheet and a frame that supports the mesh sheet. The filter F2 is disposed in the mid-way portion 20A of the air circulation path 20, for example, between the rotating blades 21A of the blower section 21 and the heat exchanger 27. The filter F2 is disposed, for example, in a vertically extending position so as to cross the air flowing through the air circulation path 20. When multiple filters F2 are provided, these filters F2 are disposed overlapping in the air flow direction in the air circulation path 20.

As mentioned above, filter F1 can be automatically maintained without removal, but filter F2 needs to be removed and maintained periodically. Therefore, a first attachment/detachment opening 20G facing filter F2 from the upper side Z1 is provided in the top wall 20F at the midpoint 20A of the air circulation path 20. A second attachment/detachment opening 2E is provided in the top wall 2B of the housing 2 at a position directly above the first attachment/detachment opening 20G. Each of the first attachment/detachment opening 20G and the second attachment/detachment opening 2E is an opening large enough to pass filter F2 through.

The washer-dryer 1 further includes a first door 31 for opening and closing the first attachment/detachment opening 20G, and a second door 32 for opening and closing the second attachment/detachment opening 2E. The first door 31 is connected to the top wall 20F of the air circulation path 20 via a hinge 33, for example, and is therefore rotatable about the hinge 33. The second door 32 is also connected to the top wall 2B of the housing 2 via a hinge 34, for example, and is therefore rotatable about the hinge 34.

The user can open the first and second openings 20G and 2E by rotating the first and second doors 31 and 32 to the upper side Z1, and remove the filter F2 in the air circulation path 20 from the air circulation path 20 to the outside of the housing 2 through the first and second openings 20G and 2E, and perform maintenance such as cleaning the filter F2. The user returns the removed filter F2 from the first and second openings 20G and 2E to the air circulation path 20, and closes the first and second openings 20G and 2E by rotating the first and second doors 31 and 32 to the lower side Z2. This completes the installation of the filter F2 in the air circulation path 20. A positioning portion (not shown) for positioning the filter F2 is provided in the air circulation path 20. The first and second doors 31 and 32 may also be integrated into one door that opens and closes the first and second openings 20G and 2E collectively. In other words, one of the first door 31 and the second door 32 may also serve as the other.

In the following, when the first and second openings 20G and 2E are closed, the filter F2 positioned at a predetermined mounting position in the air circulation path 20 so as to cross the air flowing through the air circulation path 20 is referred to as the filter F2 mounted in the air circulation path 20. On the other hand, the filter F2 that is outside the air circulation path 20 is referred to as the filter F2 that is not in the air circulation path 20, that is, the filter F2 in an unmounted state. When the filter F2 is not in the air circulation path 20, the first and second openings 20G and 2E may be in a closed state or an open state.

In the case of the filter F2 that can be removed from the air circulation path 20 to the outside of the housing 2, it is assumed that the user will forget to return the removed filter F2 to the air circulation path 20. If the drying operation is performed without the filter F2 in the air circulation path 20, the heat exchange between the heat exchanger 27 and the air in the air circulation path 20 will be slowed down due to foreign matter adhering to the heat exchanger 27, and the drying efficiency of the laundry L may decrease. Furthermore, if the first attachment/detachment opening 20G and the second attachment/detachment opening 2E are left open, the air in the air circulation path 20 will leak from these attachment/detachment openings, reducing the amount of hot air supplied from the air circulation path 20 to the laundry L, and the drying efficiency of the laundry L may further decrease. If the drying efficiency of the laundry L decreases, it will take a long time to finish drying the laundry L, and there is a concern that power consumption and drying operation will increase.

As described above, the filter F2 needs to be attached to the air circulation path 20 during the drying operation, but when the first door 31 and the second door 32 are closed, the user cannot visually check from outside the washer-dryer 1 whether the filter F2 is present in the air circulation path 20. Therefore, the control unit 30 executes a filter detection process during the drying process to detect whether the filter F2 is present in the air circulation path 20. In relation to the filter detection process, the washer-dryer 1 further includes a refrigerant temperature measuring unit 35 that measures the temperature of the refrigerant compressed by the compressor 26 in the heat pump 25, an air temperature measuring unit 36 that measures the temperature of the air in the washing tub 3, an ammeter 37 that measures the value of the current flowing through the motor 21B of the blower unit 21, and an alarm unit 38 (see also FIG. 2).

The refrigerant temperature measuring unit 35 includes a first thermometer 41, a second thermometer 42, and a third thermometer 43, all of which are constructed using thermistors. The first thermometer 41 is attached to the discharge passage 28A of the heat pump 25 and measures the temperature of the surface of the discharge passage 28A. The temperature of the surface of the discharge passage 28A is almost the same as the temperature of the refrigerant flowing through the discharge passage 28A, and can therefore be considered the temperature of the refrigerant. The first thermometer 41 may be exposed within the discharge passage 28A to measure the temperature of the refrigerant itself within the discharge passage 28A.

The second thermometer 42 is attached to the first heat exchanger 27A of the heat pump 25, i.e., the intermediate portion of the flow path 27F of the condenser, and measures the surface temperature of that intermediate portion. The surface temperature of flow path 27F is almost the same as the temperature of the refrigerant flowing in flow path 27F, and can therefore be considered the temperature of the refrigerant. The second thermometer 42 may be exposed in flow path 27F to measure the temperature of the refrigerant itself in flow path 27F.

The third thermometer 43 is attached to the inlet portion connected to the capillary tube 27C in the second heat exchanger 27B of the heat pump 25, i.e., the evaporator flow path 27G, and measures the temperature of the surface of the inlet portion. The temperature of the surface of flow path 27G is almost the same as the temperature of the refrigerant flowing in flow path 27G, and can therefore be considered the temperature of the refrigerant. The third thermometer 43 may be exposed in flow path 27G to measure the temperature of the refrigerant itself in the inlet portion of flow path 27G.

In the following, the temperature measured by the first thermometer 41 is referred to as the "temperature of the discharge passage 28A", the temperature measured by the second thermometer 42 is referred to as the "intermediate temperature of the first heat exchanger 27A", and the temperature measured by the third thermometer 43 is referred to as the "inlet temperature of the second heat exchanger 27B". The measurement results of the first thermometer 41, the second thermometer 42, and the third thermometer 43, namely the "temperature of the discharge passage 28A", the "intermediate temperature of the first heat exchanger 27A", and the "inlet temperature of the second heat exchanger 27B", are input to the control unit 30 in real time.

The air temperature measurement unit 36 includes a fourth thermometer 44 and a fifth thermometer 45, both of which are constituted by thermistors. The fourth thermometer 44 is attached near the outlet 7K of the outer tank 7 and measures the temperature of the air at the outlet 7K. The fifth thermometer 45 is attached near the inlet 7L of the outer tank 7 and measures the temperature of the air at the inlet 7L. Hereinafter, the temperature measured by the fourth thermometer 44 will be referred to as the "outlet temperature of the outer tank 7," and the temperature measured by the fifth thermometer 45 will be referred to as the "inlet temperature of the outer tank 7." The measurement results of the fourth thermometer 44 and the fifth thermometer 45, the "outlet temperature of the outer tank 7" and the "inlet temperature of the outer tank 7," respectively, are input to the control unit 30 in real time.

A known ammeter can be used as the ammeter 37. The measurement results of the ammeter 37 are input to the control unit 30 in real time. The notification unit 38 may be a liquid crystal touch panel display unit provided on the front wall 2A of the housing 2, or a buzzer built into the housing 2.

Figure 3 is a time chart showing the temperature change over time at each measurement location during drying operation with filter F2 installed in air circulation path 20. Figure 4 is a time chart showing the temperature change over time at each measurement location during drying operation with filter F2 removed from air circulation path 20. In each of the time charts in Figures 3 and 4, the horizontal axis indicates elapsed time, and the vertical axis indicates "temperature of discharge path 28A," "intermediate temperature of first heat exchanger 27A," "inlet temperature of second heat exchanger 27B," "outlet temperature of outer tub 7," and "inlet temperature of outer tub 7." The unit of elapsed time is "minutes," and the unit of temperature is "degrees."

The temperature of the refrigerant compressed by the compressor 26 of the heat pump 25 decreases as it passes through the discharge passage 28A, the first heat exchanger 27A, and the second heat exchanger 27B in sequence, so that the temperature of the discharge passage 28A is higher than the intermediate temperature of the first heat exchanger 27A, and the intermediate temperature of the first heat exchanger 27A is higher than the inlet temperature of the second heat exchanger 27B. The circulating air flows into the air circulation passage 20 from the outlet 7K of the outer tank 7, is heated by the first heat exchanger 27A, and then flows into the outer tank 7 from the inlet 7L of the outer tank 7, so that the inlet temperature of the outer tank 7 is higher than the outlet temperature of the outer tank 7.

Figure 3 shows the measurement results of the drying operation started with the filter F2 attached to the air circulation path 20. In this case, the temperature of the discharge path 28A, the intermediate temperature of the first heat exchanger 27A, the inlet temperature of the second heat exchanger 27B, the outlet temperature of the outer tub 7, and the inlet temperature of the outer tub 7 are not stable for 10 minutes after the start of the drying operation, but after 10 minutes have passed since the start of the drying operation, they constantly rise according to the operation of the blower 21 and the heat pump 25. Therefore, these temperatures are indicators of the state of the drying operation. Furthermore, since the intermediate temperature of the first heat exchanger 27A and the temperature of the discharge path 28A are also indicators of the state of the compressor 26, when these temperatures reach a predetermined upper limit value, the control unit 30 stops the drying operation to protect the compressor 26.

Figure 4 shows the measurement results of a drying operation started with the filter F2 not in the air circulation path 20 and the first attachment/detachment opening 20G of the air circulation path 20 and the second attachment/detachment opening 2E of the housing 2 open. If the user forgets to return the filter F2 to the air circulation path 20 and the drying operation is started, the temperature of the discharge path 28A and the intermediate temperature of the first heat exchanger 27A rise for 30 minutes after the start of the drying operation, but saturate and no longer rise after 30 minutes have passed since the start of the drying operation. In this case, the temperature of the discharge path 28A does not reach 60 degrees, and the intermediate temperature of the first heat exchanger 27A does not reach even 45 degrees. The inlet temperature of the second heat exchanger 27B hardly rises from the start of the drying operation and does not reach even 20 degrees.

Although the outlet temperature and inlet temperature of the outer tub 7 rise for 20 minutes after the start of the drying operation, these temperatures saturate and stop rising after 20 minutes have passed since the start of the drying operation due to the flow of outside air through the first attachment/detachment opening 20G and the second attachment/detachment opening 2E. In this case, the inlet temperature of the outer tub 7 does not reach 55 degrees, and the outlet temperature of the outer tub 7 does not reach 30 degrees.

In this way, the change characteristics of the temperature of the discharge passage 28A, the intermediate temperature of the first heat exchanger 27A, the inlet temperature of the second heat exchanger 27B, the outlet temperature of the outer tub 7, and the inlet temperature of the outer tub 7 differ depending on the presence or absence of the filter F2 in the air circulation passage 20. In particular, in a washer-dryer 1 using a heat pump 25, when the drying operation is started with the filter F2 attached to the air circulation passage 20, the temperature of the refrigerant compressed by the compressor 26 in the heat pump 25 continues to rise. Therefore, the temperature of the refrigerant after a predetermined time has elapsed since the start of the drying operation, or the degree of increase in the temperature, becomes equal to or exceeds a predetermined threshold value described below. Therefore, the control unit 30 executes a filter detection process that mainly utilizes such change characteristics of the refrigerant.

Figure 5 is a flow chart showing the filter detection process according to the first embodiment during the drying operation. When the change characteristics of the intermediate temperature of the first heat exchanger 27A are used, when the predetermined time of 30 minutes has elapsed since the start of the drying operation (YES in step S1), the control unit 30 measures the temperature of the refrigerant, which is the intermediate temperature of the first heat exchanger 27A (step S2). If this measured value is equal to or greater than a threshold value of, for example, 60 degrees (YES in step S3), the control unit 30 determines that the filter F2 is present in the air circulation path 20, terminates the filter detection process, and continues the drying operation. This threshold value is obtained in advance from the change characteristics of the intermediate temperature of the first heat exchanger 27A (see Figure 3) and is stored in the memory (not shown) of the control unit 30. The same applies to the other threshold values described below.

On the other hand, if the measured value for the intermediate temperature of the first heat exchanger 27A is less than the threshold value (NO in step S3), the control unit 30 determines that the filter F2 is not present in the air circulation path 20, and notifies the notification unit 38 that the filter F2 is not present in the air circulation path 20 (step S4). The control unit 30 then ends the filter detection process and continues the drying operation.

In the filter detection process when the temperature change characteristics of the discharge passage 28A are used, the control unit 30 also executes the processes of steps S1 to S4, but the threshold value in step S3 is set to a value obtained from the temperature change characteristics of the discharge passage 28A, for example, 65 degrees. In the filter detection process when the inlet temperature change characteristics of the second heat exchanger 27B are used, the control unit 30 also executes the processes of steps S1 to S4, but the threshold value in step S3 is set to a value obtained from the inlet temperature change characteristics of the second heat exchanger 27B, for example, 25 degrees.

Figure 6 is a flow chart showing the filter detection process according to the second embodiment during drying operation. When using the change characteristics of the intermediate temperature of the first heat exchanger 27A, when the aforementioned predetermined time of 30 minutes has elapsed since the start of the drying operation (YES in step S11), the control unit 30 measures the refrigerant temperature, which is the intermediate temperature of the first heat exchanger 27A, for the predetermined time (step S12). Then, the control unit 30 calculates Δt, which represents the degree of increase in the intermediate temperature of the first heat exchanger 27A during that predetermined time (step S13). Δt corresponds to the slope in the equation that represents the transition of the intermediate temperature of the first heat exchanger 27A.

If Δt is equal to or greater than a threshold value, such as 1 degree/min (YES in step S14), the control unit 30 determines that filter F2 is present in the air circulation path 20, terminates the filter detection process, and continues the drying operation. On the other hand, if this measurement value is less than the threshold value (NO in step S14), the control unit 30 determines that filter F2 is not present in the air circulation path 20, and notifies the notification unit 38 that filter F2 is not present in the air circulation path 20 (step S15). The control unit 30 then terminates the filter detection process and continues the drying operation.

In the filter detection process when the temperature change characteristics of the discharge passage 28A are used, the control unit 30 also executes the processes of steps S11 to S15, but the threshold value in step S14 is set to a value obtained from the temperature change characteristics of the discharge passage 28A. The same is true in the filter detection process when the inlet temperature change characteristics of the second heat exchanger 27B are used.

During the drying operation, the control unit 30 may execute only the filter detection process according to either the first or second embodiment described above, or may execute the filter detection process according to both embodiments in parallel. In either case, if the temperature measured by the refrigerant temperature measurement unit 35 after a predetermined time has elapsed since the start of the drying operation, or the degree of increase in the temperature Δt, is less than a predetermined threshold value, the control unit 30 determines that the filter F2 is not present in the air circulation path 20 (steps S4 and S15). By focusing on the temperature of the refrigerant in the heat pump 25 in this way, it is possible to accurately determine whether the filter F2 for the drying operation is installed at low cost without employing an expensive sensor or the like for detecting whether the filter F2 is installed.

In particular, when the drying operation is started with the filter F2 attached to the air circulation path 20, the intermediate temperature of the first heat exchanger 27A and the temperature of the discharge path 28A tend to continue to rise significantly compared to the inlet temperature of the second heat exchanger 27B (see FIG. 3). Therefore, by focusing on these temperatures, it is possible to accurately determine whether the filter F2 is attached or not.

If the control unit 30 determines that the filter F2 is not present in the air circulation path 20, the notification unit 38 notifies the user that the filter F2 is not present in the air circulation path 20 (steps S4 and S15). This makes it possible to prompt the user to attach the filter F2 to the air circulation path 20.

As described above, in the washer/dryer 1, when the drying operation is started with the filter F2 attached to the air circulation path 20, the circulating air is repeatedly heated by the heat exchanger 27, so that the temperature of the air in the washing tub 3 continues to rise (see FIG. 3). As a result, the air temperature or the degree of rise in temperature after a predetermined time has elapsed since the start of the drying operation becomes equal to or exceeds a predetermined threshold value.

Therefore, in addition to the filter detection process using the change characteristics of the refrigerant temperature as described above, the control unit 30 may also execute a filter detection process using the change characteristics of the air in the washing tub 3. As a filter detection process using the change characteristics of the air in the washing tub 3, the control unit 30 executes the processes of steps S1 to S4 or steps S11 to S15, but the predetermined time in steps S1 and S11 and the threshold value in steps S3 and S14 are set to values obtained from the change characteristics of the outlet temperature and inlet temperature of the outer tub 7. An example of the predetermined time is set to 20 minutes. An example of the threshold value in step S14 is set to 1 degree/minute.

In this way, even if the temperature measured by the air temperature measuring unit 36 after a predetermined time has elapsed since the start of the drying operation, or the degree of increase in the temperature Δt, is less than a predetermined threshold value, the control unit 30 may determine that the filter F2 is not in the air circulation path 20. In this way, by focusing on not only the temperature of the refrigerant of the heat pump 25 but also the temperature of the air in the washing tub 3, it is possible to determine at low cost whether the filter F2 is installed.

When there is no filter F2 in the air circulation path 20, the air resistance in the air circulation path 20 decreases, and the current value of the motor 21B of the blower 21 tends to increase. Therefore, the control unit 30 may execute a filter detection process that utilizes such current characteristics of the motor 21B as the filter detection process according to the third embodiment.

Figure 7 is a flow chart showing the filter detection process according to the third embodiment during the drying operation. When a predetermined time, for example, 10 minutes, has elapsed since the start of the drying operation, the rotation speed of the motor 21B stabilizes at, for example, 5000 rpm. In this case (YES in step S21), the control unit 30 measures the current value of the motor 21B, which is still operating, using the ammeter 37 (step S22). If this measured value is less than a threshold value, for example, 290 mA (NO in step S23), the control unit 30 determines that the filter F2 is present in the air circulation path 20, terminates the filter detection process, and continues the drying operation. On the other hand, if this measured value is equal to or greater than the threshold value (YES in step S23), the control unit 30 determines that the filter F2 is not present in the air circulation path 20, and notifies the notification unit 38 that the filter F2 is not present in the air circulation path 20 (step S24). Then, the control unit 30 terminates the filter detection process and continues the drying operation.

Figure 8 is a flow chart showing the drying operation. During the drying operation, the control unit 30 executes the filter detection process according to at least one of the first and second embodiments described above, but may also execute the filter detection process according to the third embodiment in parallel (step S31). If the control unit 30 determines in the filter detection process that there is no filter F2 in the air circulation path 20 (YES in step S32), it executes an extension process to extend the drying operation (step S33). As an example of the extension process, the control unit 30 extends the operation time of the drying operation itself from the initially set operation time by, for example, 30 minutes. The initial operation time is set according to the amount of laundry L at the start of the washing operation, etc.

As an example of the extension process, the control unit 30 changes the drying end judgment reference temperature at which the end of drying of the laundry L can be determined. Examples of the drying end judgment reference temperature include a high limiter temperature for the outlet temperature of the outer tub 7 and a temperature difference judgment temperature for the difference between the outlet temperature of the outer tub 7 and the inlet temperature of the outer tub 7. When the outlet temperature of the outer tub 7 rises to the high limiter temperature or the difference between the outlet temperature of the outer tub 7 and the inlet temperature of the outer tub 7 decreases to the temperature difference judgment temperature, the end of drying of the laundry L can be determined. As an example of the extension process, the control unit 30 increases the high limiter temperature by, for example, 3 degrees from the initial high limiter temperature, or decreases the temperature difference judgment temperature by, for example, 3 degrees from the initial temperature difference judgment temperature. The initial temperature difference judgment temperature is set according to the amount of laundry L at the start of the washing operation, etc. When the drying end judgment reference temperature is changed by the extension process in this way, the operation time of the drying operation is substantially extended.

Regardless of whether or not the extension process is performed, if the operation end conditions are met (YES in step S34), the control unit 39 ends the drying operation. The operation end conditions are met when the operation time has elapsed, when the outlet temperature of the outer tub 7 has risen to the high limiter temperature, or when the difference between the outlet temperature of the outer tub 7 and the inlet temperature of the outer tub 7 has decreased to the temperature difference judgment temperature.

In this way, when the control unit 30 determines that the filter F2 is not in the air circulation path 20 (YES in step S32), it extends the drying operation (step S33). Therefore, even if the laundry L in the washing tub 3 is difficult to dry because the filter F2 is not in the air circulation path 20, the laundry L can be dried to the end.

This invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims.

For example, the filter unit 22 equipped with the filter F1, the branch passage 23 for maintenance of the filter F1, and the water injection valve 24 (see FIG. 1) may be omitted.

In the embodiment described above, whether or not the filter F2 is in the air circulation path 20 is detected mainly based on the temperature of the refrigerant. Even if the filter F2 is in the air circulation path 20, if the change characteristics of the refrigerant temperature differ significantly depending on whether the filter F2 is in the installation position described above, whether or not the filter F2 in the air circulation path 20 is in the installation position may be detected based on the temperature of the refrigerant. This makes it possible to determine whether or not the filter F2 is correctly installed in the air circulation path 20, and, if necessary, the user can be prompted to reinstall the filter F2 by a notification from the notification unit 38.

In the above-described embodiment, the filter detection process based on the refrigerant temperature is executed as the main filter detection process. In addition to this, the filter detection process based on the air temperature in the washing tub 3 or the filter detection process according to the third embodiment based on the current value of the motor 21B of the blower 21 may be executed alone as the main filter detection process.

In addition, in the drum-type washer-dryer 1 in the above-described embodiment, the washing tub 3 may be arranged so that the axis J is inclined with respect to the horizontal direction H. In addition, the washer-dryer 1 may be a vertical washer-dryer in which the axis J extends vertically.

REFERENCE SIGNS LIST 1 washer-dryer 2 housing 2E second attachment/detachment opening 3 washing tub 20 air circulation path 20D take-out opening 20E return opening 20G first attachment/detachment opening 21 air blower 25 heat pump 26 compressor 27 heat exchanger 27A first heat exchanger 27B second heat exchanger 27F flow path 28 refrigerant circulation path 28A discharge path 28B return path 30 control unit 31 first door 32 second door 35 refrigerant temperature measuring unit 36 air temperature measuring unit 38 notification unit F2 filter L laundry

Claims (4)

A housing and
A washing tub disposed in the housing and configured to accommodate laundry;
An air circulation path including an outlet and a return port disposed in the housing and connected to the washing tub;
A blower unit that circulates air in the washing tub by taking the air from the outlet into the air circulation path and returning the air from the return port into the washing tub;
a heat pump including a compressor that compresses a refrigerant, a heat exchanger that is disposed in the air circulation path and performs heat exchange between the refrigerant and the air in the air circulation path, and a refrigerant circulation path that circulates the refrigerant between the compressor and the heat exchanger;
a filter disposed in the air circulation path to capture foreign matter from the air in the air circulation path;
a refrigerant temperature measuring unit that measures the temperature of the refrigerant compressed by the compressor;
a control unit that executes a drying operation for drying the laundry in the washing tub by controlling the air blowing unit and the heat pump;
a first door for opening and closing a first attachment/detachment opening provided in the air circulation path;
a second door for opening and closing a second attachment/detachment opening provided in the housing ;
An air temperature measuring unit for measuring the temperature of air in the washing tub ,
the filter is removable from the air circulation path to the outside of the housing through the first attachment/detachment opening and the second attachment/detachment opening;
When the temperature measured by the refrigerant temperature measuring unit after a predetermined time has elapsed since the start of the drying operation or the degree of increase in the temperature is less than a predetermined threshold value, the control unit determines that the filter is not in the air circulation path ,
In a washer-dryer, when the temperature measured by the air temperature measuring unit after a predetermined time has elapsed since the start of the drying operation, or the degree of increase in the temperature, is less than a predetermined threshold, the control unit determines that the filter is not in the air circulation path . the heat exchanger includes a first heat exchanger that is heated by the refrigerant compressed by the compressor, and a second heat exchanger that is cooled by the refrigerant that has passed through the first heat exchanger;
the refrigerant circulation path includes a discharge path that guides the refrigerant compressed by the compressor to the first heat exchanger, and a return path that guides the refrigerant from the second heat exchanger to the compressor,
The washer/dryer according to claim 1 , wherein the temperature measured by the refrigerant temperature measuring unit is a temperature of a refrigerant flow path in the first heat exchanger or a temperature of the discharge path. The washing/drying machine according to claim 1 , further comprising a notification unit that notifies a user that the filter is not present in the air circulation path when the control unit determines that the filter is not present in the air circulation path. The washer/dryer according to any one of claims 1 to 3 , wherein the control unit extends the drying operation when it determines that the filter is not present in the air circulation path.

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