Washer dryer

Abstract

To provide a washer-dryer that can properly dry clothes. [Solution] The washer-dryer 100 includes an outer tub 130, a heater 232, a dehumidifier 233, discharge air passages 310, 320, 330 through which air blown from a blower 211 flows, a discharge port 340 connected to the discharge air passages and blowing air into the outer tub, a return air passage 156 that returns air from the outer tub to the blower, a drying filter (primary filter 152 and secondary filter 154) for catching lint generated from clothes, intake ports 223, 224 between the outer tub and the blower, and a drainage path 160 and an overflow path 180 connecting the outer tub and the drain port 190. The washer-dryer is equipped with a drain solenoid valve 176 and an overflow solenoid valve 182 in the drainage path and the overflow path, respectively.

Description

Technical Field

[0001] The present invention relates to a washing and drying machine.

Background Art

[0002] As the background art in this technical field, there is what is described in Patent Document 1. Patent Document 1 describes "a water tank elastically supported in a housing, a rotary tank rotatably provided in the water tank, a motor for rotationally driving the rotary tank, a water supply means for supplying washing water to the water tank, a drainage means for discharging the washing water in the water tank, a drainage path for discharging the washing water in the water tank to the outside of the housing through the drainage means, a circulation air path for introducing drying air into the water tank, a blowing means for blowing air into the circulation air path, a dehumidifying means for dehumidifying the drying air discharged from the water tank, a heating means for heating the drying air dehumidified by the dehumidifying means, a drying filter device for capturing lint contained in the drying air, a pressure detection means for detecting the pressure in the water tank, and a control means for controlling washing and drying operations. The drainage path has a drainage trap formed in a substantially U shape in the housing, and the control means reduces the rotational speed of the blowing means when the pressure in the water tank rises and reaches a predetermined value during the drying operation."

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The drain trap structure disclosed in Patent Document 1 has the role of sealing the water seal with a water head difference to prevent circulating air from flowing into the drain outlet during drying. Therefore, it is necessary to make the water seal height high, but there are constraints on the water seal height in order to prevent too much water from accumulating in the tank. As a result, if lint (thread) adheres to the drying filter device (hereinafter referred to as the drying filter), the pressure in the tank will rise and exceed the head difference of the drain trap, causing the water in the drain trap to drain, which in turn causes some of the circulating air to flow to the drain outlet, resulting in the risk of increased drying time and decreased energy efficiency. In addition, while it is possible to make it more difficult for water to drain from the trap on the drain channel side during drying by reducing the rotation speed of the blower, the reduced airflow can lead to increased drying time and decreased energy efficiency, so there was room for improvement.

[0005] The present invention was made to solve the aforementioned problems, and its main objective is to provide a washing machine that does not increase drying time, does not reduce energy efficiency, and prevents the water seal in the drain channel from easily dissipating during the drying of clothes. [Means for solving the problem]

[0006] To achieve the above objective, the present invention provides a washing and drying machine comprising: an outer tub; a heater; a dehumidifier; a discharge air passage through which air blown from a blower flows; a discharge port connected to the discharge air passage and blowing air into the outer tub; a return air passage that returns air from the outer tub to the blower; a drying filter for catching lint generated from clothing; an air intake port between the outer tub and the blower; and a drainage path and an overflow path connecting the outer tub and a drain port, wherein a drainage solenoid valve and an overflow solenoid valve are provided in the drainage path and the overflow path, respectively. Other methods will be described later. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a washing machine with a dryer in which the water seal in the drain channel is less likely to come loose during the drying of clothes. [Brief explanation of the drawing]

[0008] [Figure 1] It is a perspective view of a washing and drying machine according to an embodiment. [Figure 2] It is a schematic central cross-sectional view of a washing and drying machine. [Figure 3] It is an exploded perspective view of a washing and drying machine. [Figure 4] It is another exploded perspective view of a washing and drying machine. [Figure 5] It is a perspective view of a drying device. [Figure 6] It is a top view of a drying device. [Figure 7] It is a perspective view of a drying device with the upper casing removed. [Figure 8] It is a perspective view of a blower. [Figure 9] It is a partially cut-away rear view of a washing and drying machine. [Figure 10] It is an enlarged view of the upper part of FIG. 9. [Figure 11] It is a perspective view of the main part of a washing and drying machine. [Figure 12] It is a rear view of a tub cover. [Figure 13] It is a schematic diagram of a drainage path. [Figure 14] It is a diagram showing the relationship between the air duct position and pressure in a state where the filter is not clogged. [Figure 15] It is a diagram showing the relationship between the air duct position and pressure in a state where the filter is clogged. [Figure 16] It is a diagram showing the relationship between the clogging of the secondary filter and the internal pressure of the outer tub. [Figure 17] [[ID=|49]]It is a diagram showing the shape of the mesh part of the filter. [Figure 18A] It is a diagram (1) excerpting a part of the A-A cross-section of FIG. 17. [Figure 18B] It is a diagram (2) excerpting a part of the A-A cross-section of FIG. 17. [Figure 18C] It is a diagram (3) excerpting a part of the A-A cross-section of FIG. 17. [Figure 19] It is a diagram showing the relationship between the opening ratio of the secondary filter and the capillary force of the water film formed on the filter. [Figure 20]It is a diagram showing the relationship between the secondary filter aperture ratio, the internal pressure of the outer tub, and the capillary force of the filter.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention (hereinafter referred to as "the present embodiment") will be described in detail with reference to the drawings. Note that each drawing only schematically shows the present invention to such an extent that it can be sufficiently understood. Therefore, the present invention is not limited only to the illustrated examples. Also, in each drawing, common components and similar components are denoted by the same reference numerals, and redundant descriptions thereof are omitted.

[0010] FIG. 1 is a perspective view of a washing and drying machine 100 according to the present embodiment. The washing and drying machine 100 is a drum-type washing and drying machine, and a base 102 is provided at its lower end. A substantially rectangular parallelepiped frame-shaped housing 110 is mounted on the upper surface of the base 102. The housing 110 includes side plates 112, a reinforcing member (not shown), a front cover 114, and an upper cover 116.

[0011] The side plates 112 are mainly formed of a steel plate and a resin molded product. By combining the side plates 112 and a reinforcing member (not shown), the framework of the housing 110 is constituted. The front cover 114 and the upper cover 116 are mounted on this framework. A door 120 for loading and unloading laundry is provided on the front cover 114. An operation panel 122 is provided at the upper front part of the housing 110. The operation panel 122 is provided with a power switch, buttons for selecting a washing course, and the like. Also, a lid portion 124 is mounted on the upper cover 116. The lid portion 124 covers the upper part of a detergent box (not shown) and a softener box (not shown).

[0012] (Outer tub 130 and rotary drum 140) FIG. 2 is a schematic central cross-sectional view of the washing and drying machine 100. As shown in Figure 2, an outer tub 130 is provided inside the housing 110. The outer tub 130 is supported by multiple suspensions (not shown) and its upper part is suspended by a spring (not shown). Inside the outer tub 130, a rotating drum 140 (inner tub) is provided. The user opens the door 120 and puts the laundry 510 into the rotating drum 140.

[0013] Furthermore, during the spin-drying process, vibrations may occur due to an imbalance in the laundry 510. Therefore, a fluid balancer 142 is provided on the outer circumference of the opening of the rotating drum 140 to reduce these vibrations. In addition, multiple lifters 144 are provided inside the rotating drum 140 to lift the laundry 510. The rotating drum 140 is directly connected to a drum drive motor 149 via a main shaft 148 connected to a metal flange 146 for the rotating drum.

[0014] A tank cover 132 is provided in front of the outer tank 130, and an elastic rubber bellows 134 is fitted to the opening of the tank cover 132. This bellows 134 plays a role in maintaining watertightness between the inside of the outer tank 130 and the door 120. This prevents water leakage during washing, rinsing, and spin-drying. The rotating drum 140 has numerous small holes (not shown) on its sides and back for centrifugal dewatering and ventilation. In addition, a water receiving section 136 is provided at the bottom of the outer tank 130.

[0015] An internal duct 150 is provided at the rear of the outer tank 130. The internal duct 150 communicates with the outer tank 130 via a primary filter 152 and with the return air passage 156 via a secondary filter 154. Above the secondary filter 154, a cleaning nozzle 153 is positioned for cleaning the secondary filter 154. Furthermore, a drainage path 160 and a heat pump unit 220 are provided below the outer tank 130.

[0016] The return air passage 156 and the heat pump unit 220 are connected by a return bellows 158. The return air passage 156 is a component made by fixing two resin plates (not indicated) together by vibration welding and is screw-fixed to the outer tank 130. The return bellows 158 is made of a flexible, bellows-shaped rubber material so that vibrations of the outer tank 130 and the return air passage 156 do not affect the heat pump unit 220.

[0017] (Internal flow path and filter) Figure 3 is an exploded perspective view of the washer-dryer 100. Specifically, Figure 3 shows the outer tank 130 with the tank cover 132 removed, and the rotating drum 140, the fluid balancer 142, and the outer tank 130 partially cut out. More specifically, Figure 3 shows the right half of the outer tank 130 and the right half of the rotating drum 140 cut out. The outer tank 130 is formed in a bottomed cylindrical shape, and the tank cover 132 is provided at the front opening of the outer tank 130.

[0018] The primary filter 152 has a mesh-shaped collection section, but in Figure 3, this mesh-shaped collection section is removed. As described above, an internal duct 150 is provided on the rear part of the outer tub 130. During the washing and rinsing cycles, the rotating drum 140 becomes stationary as needed.

[0019] The drum cover 132 has a circulation channel 132a through which the washing water pumped up by the circulation pump 186 (see Figure 13) passes. A watering nozzle 132b is formed at the end of the drum cover 132. The drum cover 132 also has a discharge air passage 330 through which drying air flows, and a discharge port 340 from which the drying air is blown out. In the example shown in Figure 3, the discharge air passage 330 is located in front of the rotating drum 140, but the discharge air passage 330 may also be located behind the rotating drum 140, for example at position PS as shown in Figure 3.

[0020] Figure 4 is another exploded perspective view of the washer-dryer 100. Specifically, Figure 4 is a perspective view with the rotating drum 140, primary filter 152, washing nozzle 153, and secondary filter 154 removed from the outer tub 130. The in-tub duct 150 has a curved, roughly arc-shaped form that curves from the top to the right of the outer tub 130 to avoid the motor 149 (see Figure 2) that drives the rotating drum 140.

[0021] The primary filter 152 comprises a roughly rectangular resin frame having multiple compartments and a mesh-shaped collection section (not shown). When the rotating drum 140 is driven with water stored in the outer tank 130, the stored water is lifted up to the primary filter 152. This allows the primary filter 152 to be cleaned.

[0022] A communication port 155 is formed on the upper rear of the outer tank 130, which communicates with the outside of the outer tank 130. On the outer rear of the outer tank 130, a return air passage 156 (see Figure 2) is connected to the communication port 155. In other words, the communication port 155 is the connection point between the return air passage 156 and the outer tank 130. A secondary filter 154 is installed in the communication port 155.

[0023] The secondary filter 154 comprises a resin frame divided into multiple sections and having a roughly rectangular shape, and a mesh-shaped collection section (not shown). A cleaning nozzle 153 is provided on the top of the secondary filter 154. The cleaning nozzle 153 washes the secondary filter 154 by flowing cleaning water through it. Furthermore, the cleaning nozzle 153 also plays a role in sealing the resin frame of the secondary filter 154 from the outside air by pressing it from above.

[0024] Furthermore, by employing a two-filter configuration consisting of a primary filter 152 and a secondary filter 154 in the direction of airflow, a planar overlap of the mesh can be achieved, allowing for a coarser mesh (opening) compared to a single-filter configuration. This ensures that lint is collected across both filters, preventing dense accumulation of lint and maintaining stable air circulation. However, there is a possibility that both the primary filter 152 and the secondary filter 154 may become blocked, and this blockage cannot be resolved even by cleaning. In the event of such a situation, the secondary filter 154 is detachable from the communication port 155 so that it can be removed and cleaned.

[0025] (Drying device 200) Figure 5 is a perspective view of the drying apparatus 200. The drying apparatus 200 includes a blower 210 and a heat pump unit 220. In this embodiment, a hot air drying method is applied as the drying method. That is, the air between the rotating drum 140 (see Figure 2) and the heat pump unit 220 is circulated by the blower 210. The drying apparatus 200 dehumidifies the circulating air and then heats it. Furthermore, the heat pump drying system has high energy-saving performance because it can reuse the energy that would otherwise be wasted during dehumidification for heating, thus ensuring sufficient heating with less input energy. The heat pump unit 220 includes a casing 222, which is separable into a lower casing 222D and an upper casing 222U.

[0026] Figure 6 is a top view of the drying apparatus 200. The blower 210 comprises an impeller 212 (see Figure 8), a motor 214 that rotates the impeller 212, and a fan casing 216 that houses the impeller 212. Inside the casing 222 are a compressor 231, a heater 232 (condenser), a dehumidifier 233 (evaporator), and refrigerant piping 234.

[0027] A portion of the refrigerant piping 234 forms an expansion valve 235 (expansion mechanism). Additionally, air intake ports 223 and 224, and a dehumidifier cleaning piece 225 are located on the upper surface of the upper casing 222U. Air intake port 223 is provided for drawing in outside air. Air intake port 224 is provided for taking in circulating air flowing from the outer tank 130 via the return air passage 156. The dehumidifier cleaning piece 225 flows cleaning water to the front surface (right side in Figure 6) of the dehumidifier 233.

[0028] Figure 7 is a perspective view of the drying apparatus 200 with the upper casing 222U removed. As shown in Figure 7, the compressor 231 is connected to the heater 232 and dehumidifier 233 via refrigerant piping 234. The heater 232 and dehumidifier 233 are installed so as to be tightly sandwiched within the casing 222, preventing air from flowing through their sides. This creates an air circulation path from right to left in Figure 7.

[0029] A cross-fin tube type heat exchanger is used in the heater 232 and the dehumidifier 233. That is, heat transfer tubes are installed so as to penetrate stacked aluminum fins (not shown) in order to exchange heat with air. The compressor 231 is installed in the lower casing 222D via vibration-damping rubber (not shown), etc. The compressor 231 can be of the type such as piston, rotary, or scroll, and its rotational speed is variable from low to high speed by inverter control. The refrigerant piping 234 is connected to each part in a meandering manner to prevent it from rupturing due to the propagation of rotational vibrations from the compressor 231.

[0030] The refrigerant flow in the heat pump unit 220 is as follows: First, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 231 flows into the heater 232, where it condenses and liquefies by releasing heat into the circulating air. The liquefied refrigerant is depressurized by the expansion valve 235, which is adjusted to a predetermined opening, becoming a low-temperature, low-pressure gas-liquid two-phase state, and flows into the dehumidifier 233. There, by absorbing heat from the circulating air, the refrigerant evaporates and vaporizes. The vaporized refrigerant becomes a medium-temperature, low-pressure refrigerant and is drawn into the compressor 231. The medium-temperature, low-pressure refrigerant is compressed again by the compressor 231 to become a high-temperature, high-pressure gaseous refrigerant. In this way, a refrigerant cycle is formed, and the drying of clothes is promoted as the circulating air is dehumidified and heated.

[0031] Figure 8 is a perspective view of the blower 210. As described above, the blower 210 comprises an impeller 212, a motor 214, and a fan casing 216. The blower 210 is located downstream of the heat pump unit 220 (see Figure 7).

[0032] (Airflow path configuration) Returning to Figure 2, in the washer-dryer 100, an air circulation passage is formed between the heat pump unit 220 and the outer tub 130 so that the air used to dry the laundry circulates between the heat pump unit 220 and the rotating drum 140. The air passage that sends air from the outer tub 130 to the heat pump unit 220 includes, from the upstream side of the air, a primary filter 152, an in-tub duct 150, a secondary filter 154, a return air passage 156, and a return bellows 158.

[0033] Figure 9 is a partially cutaway rear view of the washing machine / dryer 100. In Figure 9, a discharge air passage 310 extending in a substantially vertical direction is connected to the blower 210. The upper end of the discharge air passage 310 is connected to a discharge air passage 320 extending in a substantially horizontal direction. The return air passage 156 is formed in a substantially inverted L shape. A circuit board case 512 and a water supply unit 520 are provided at the top of the washing machine / dryer 100. The dehumidifier cleaning hose 518 supplies water to the dehumidifier cleaning piece 225 (see Figure 6).

[0034] Figure 10 is an enlarged view of the upper part of Figure 9. A cleaning nozzle 153 is mounted on the upper surface of the return air passage 156, forming part of the air passage of the return air passage 156. The cleaning nozzle 153 is also fitted with a secondary filter cleaning hose 532 for supplying cleaning water and an exhaust bellows 352. The exhaust bellows 352 is connected to the exhaust case 354. An exhaust port 901, which connects to the outside of the machine, is provided on the downstream side of the exhaust case 354.

[0035] As described above, the heat pump unit 220 (see Figure 6) draws in outside air from the intake port 223. Then, the highly humid air that has passed through the clothes is exhausted from the exhaust port 901 formed downstream of the exhaust case 354. This enhances the dehumidification performance. The exhaust case 354 is also equipped with a flap (not shown) that can be opened and closed by a stepping motor. Therefore, the opening and closing timing of the flap is adjusted according to the conditions inside the tank and the outside air to balance heating and dehumidification.

[0036] Figure 11 is a perspective view of the main parts of the washing machine / dryer 100. The air passage that sends air from the blower 210 to the outer tank 130 includes, from the upstream side of the air, a discharge passage 310, a discharge passage 320, a discharge bellows 322, a discharge passage 330, and a discharge port 340 (see Figure 3).

[0037] The discharge air passage 310 is a blow-molded resin part and is connected to the blower 210 and the discharge air passage 320 by fitting them in from above and below. The discharge air passage 320 is a resin part formed by fixing two resin plates with a roughly π-shaped cross-section together with screws. The discharge bellows 322 is connected to the downstream side of the discharge air passage 320, and the discharge air passage 330 is connected to the downstream side of the discharge bellows 322. The discharge bellows 322 is made of a bellows-shaped rubber material that can expand and contract to prevent vibrations of the discharge air passage 330 from affecting the discharge air passage 320. The discharge air passages 310 and 320 are positioned to maintain a distance of at least a predetermined interval from the outer tank 130. This ensures that the discharge air passages 310 and 320 do not come into contact with the outer tank 130 when the outer tank 130 vibrates.

[0038] Figure 12 is a rear view of the tank cover 132. The discharge air passage 330 is an internal flow path located on the front side of the tank cover 132. A discharge port 340 is formed at the outlet of the discharge air passage 330. The discharge port 340 is positioned to open towards the inside of the rotating drum 140. In this way, the warm air discharged from the discharge port 340 can be directed directly onto the clothes inside the drum, allowing wrinkles in the clothes to be efficiently smoothed out.

[0039] (Drainage route) Figure 13 is a schematic diagram of the drainage route 160. The drainage route 160 includes a drainage channel 170 and an overflow route 180. Here, the drainage channel 170 is a route for draining water accumulated in the outer tank 130. The overflow route 180 is a route for draining excess water when the water accumulated in the outer tank 130 exceeds a predetermined water level.

[0040] The drainage channel 170 comprises an internal drainage channel 172, a channel filter 174, a drain solenoid valve 176, and a drainage hose 178. The internal drainage channel 172 is connected to the bottom of the outer tank 130, and the channel filter 174 collects lint (lint) in the wastewater flowing through the internal drainage channel 172. The lint collected by the channel filter 174 is cleaned by the user as needed. An overflow solenoid valve 182 is also provided in the middle of the overflow path 180. The overflow path 180 downstream of the overflow solenoid valve 182 is connected to the drainage hose 178. The drain solenoid valve 176 and the overflow solenoid valve 182 can allow water to flow and shut off water, and shutting off water can block the flow of air.

[0041] Meanwhile, a condensation hose 252 is connected to the heat pump unit 220 via a condensation water pump 250. The condensation water pump 250 discharges the water dehumidified by the heat pump unit 220 through the condensation water hose 252. This condensation water hose 252 is connected to the downstream side of the overflow solenoid valve 182.

[0042] The condensation water hose 252 is configured to prevent backflow from the drain hose 178 to the heat pump unit 220. Specifically, the condensation water hose 252 has a portion that rises to a higher position vertically than the overflow path 180 between the condensation water pump 250 and the drain hose 178. In addition, a circulation water channel 184 and a circulation pump 186 are provided between the drain channel 170 and the outer tank 130. These allow the water in the outer tank 130 to be circulated back into the outer tank 130 via the water channel filter 174 as needed.

[0043] On the downstream side of the drain hose 178, there is an internal water seal trap section 179 that rises to a high position in the vertical direction to seal the inside of the drain hose 178 with water and prevent odors from returning from the drain outlet 190. By sealing the inside of the drain hose 178 with water, odors can be prevented from returning from the drain outlet 190 even when both the drain solenoid valve 176 and the overflow solenoid valve 182 are open.

[0044] (Operation and pressure characteristics during drying) Next, we will explain the operation of the washer-dryer 100 during the drying cycle and the relationship between the pressures in each part. After the washing and spin-drying cycles are completed, the drain solenoid valve 176 and the overflow solenoid valve 182 are closed. Then, the blower 210 and the compressor 231 are driven to start the drying cycle.

[0045] Figure 14 shows the relationship between the airflow path position and pressure when the filter is not clogged. Figure 14 shows the rotation speed of the blower 210 at 10,000 min⁻¹. -1 This shows the pressure when driven by [the specified method]. In this embodiment, the washing machine dryer has an air intake 223 between the dehumidifier 233 and the heater 232, so the air intake 223 of the heat pump unit 220 is always at atmospheric pressure (gauge pressure of 0 Pa). Therefore, the inlet side of the blower 210, which is near the air intake 223, will have a pressure close to 0 Pa regardless of the rotation speed of the blower 210. On the other hand, the outlet side of the blower will have a pressure of approximately 2800 Pa (10000 min) depending on the rotation speed of the blower 210. -1 (During operation) After being pressurized by the blower 210, the pressure decreases due to airflow losses in the discharge air passage 310, discharge air passage 320, discharge bellows 322, discharge air passage 330, and discharge port 340, and the internal pressure (static pressure) of the outer tank 130 becomes approximately 1000 Pa. Subsequently, the pressure decreases due to airflow losses in the primary filter 152 and secondary filter 154, return bellows 158, and return air passage 156, and becomes 0 Pa at the intake port 223 of the heat pump unit 220.

[0046] Figure 15 shows the relationship between the airflow path position and pressure when the filter is clogged. Figure 15 shows the case when the secondary filter 154 is completely blocked. During the drying operation, lint and other debris are generated from the clothes and adhere to the primary filter 152 and the secondary filter 154, increasing the airflow resistance. As a result, the operating point of the blower 210 shifts to the low-airflow, high-pressure side, reducing the airflow of the circulating air and increasing the pressure on the outlet side of the blower 210. When the secondary filter 154 is completely blocked, the airflow becomes zero, and the pressure from the outlet side of the blower 210 to the secondary filter 154 becomes uniformly high (see Figure 15).

[0047] (Key Feature 1) In this embodiment, by keeping the drain solenoid valve 176 and the overflow solenoid valve 182 closed during drying operation, even if the internal pressure (static pressure) of the outer tank 130 increases due to the operation of the blower 210, circulating air does not flow into the drain hose 178, and the water seal in the drain hose 178 is maintained. By providing the overflow solenoid valve 182 in the overflow path in this way, the limitations on pressure resistance performance due to installation height constraints, as in the conventional structure described in Patent Document 1, in which a U-shaped drain trap is provided in the overflow path, are eliminated, and the pressure resistance performance of the overflow path can be increased, making it more difficult for the water seal of the drain hose 178 to break. Furthermore, this embodiment can increase pressure resistance performance compared to the conventional structure in which a U-shaped drain trap is provided in the overflow path without reducing the rotation speed of the blower 210, making it more difficult for the water seal of the drain hose 178 to break without increasing the drying time or reducing energy efficiency.

[0048] (Key Feature 2) Figure 16 shows the relationship between secondary filter clogging and the internal pressure of the outer tank. Figure 16 shows the maximum rotational speed of the blower 210 during standard operation in drying operation at 10,000 min⁻¹. -1 The solid line shows the internal pressure of the outer tank 130 when driven, and the dotted lines show the pressure resistance of the drain solenoid valve 176 and the overflow solenoid valve 182. The horizontal axis, the secondary filter opening ratio, is a dimensionless number representing the degree of filter clogging. Here, standard operation refers to operation in the standard wash-and-dry course, with 3 kg of bath towels loaded into the rotating drum 140, with the primary filter 152 and secondary filter 154 opening ratios at 100%, and the ambient temperature at 20°C.

[0049] As shown in Figure 16, when the secondary filter opening ratio is 100%, that is, when no lint adheres to the drying filter (primary filter 152 and secondary filter 154), the internal pressure of the outer tank 130 is approximately 1000 Pa. However, when the secondary filter opening ratio becomes 0%, that is, when it is completely clogged and almost no air flows through, the internal pressure of the outer tank 130 becomes approximately 3000 Pa. In this embodiment, the maximum value of the internal pressure (static pressure) of the outer tank 130 in standard operation is Pdmax = 3000 Pa. The pressure resistance of the drain solenoid valve is set to Pr1 = 5000 Pa and the pressure resistance of the overflow solenoid valve is set to Pr2 = 5000 Pa. Since the relationship Pr1 > Pdmax and Pr2 > Pdmax is met, it is possible to more reliably prevent the water seal of the drain hose 178 from leaking.

[0050] (Key Feature 3) Furthermore, as shown in Figures 11 and 12, in this embodiment, the circulating air discharged from the blower 210 is blown directly onto the clothes from the front of the washing machine 100 through the discharge port 340, without passing through the rotating drum 140. This efficiently smooths out wrinkles in the clothes, improving the drying finish of the clothes after drying. On the other hand, because the air passage from the blower 210 to the outer tub 130 is long and complex, the air passage resistance of the discharge air passage 310, discharge air passage 320, discharge bellows 322, and discharge air passage 330 increases compared to when the discharge port 340 is located behind the rotating drum 140, for example at position PS in Figure 3. Therefore, the maximum static pressure Pdmax inside the outer tub 130 increases when either the primary filter 152 or the secondary filter 154 becomes blocked and the airflow of circulating air approaches zero. In other words, if the discharge port 340 is placed on the front side of the washing machine 100 to smooth out wrinkles in clothes and improve the drying finish, the maximum static pressure Pdmax inside the outer tub 130 increases, which creates a problem in that the water seal of the drain hose 178 is more likely to break. In the case where a U-shaped drain trap is provided in the overflow path as described in Patent Document 1 (conventional structure), there was a high risk of the water seal of the drain hose 178 being broken. However, in this embodiment, by providing an overflow solenoid valve 182 in the overflow path 180, the pressure resistance performance of the overflow path 180 is improved, thus achieving both improved drying finish and prevention of the water seal of the drain hose 178 being broken.

[0051] (Key Feature 4) Furthermore, in this embodiment, the opening area of ​​the discharge port 340 is narrowed to approximately 1900 mm², and configured to have the smallest cross-sectional area in the circulating air passage, thereby increasing the air velocity of the circulating air discharged from the blower 210. As a result, wrinkles in clothing are efficiently smoothed out, improving the drying finish of the clothes after drying. On the other hand, as the air passage area of ​​the discharge port 340 is reduced, the air passage resistance increases compared to when the opening area of ​​the discharge port is larger, for example, 3000 mm² or more. In other words, if the opening area of ​​the discharge port 340 is narrowed in an attempt to smooth out wrinkles in clothes and improve the drying finish, the maximum static pressure Pdmax inside the outer tub 130 increases, which creates a problem in that the water seal of the drain hose 178 is more likely to break. In the case where a U-shaped drain trap is provided in the overflow path as described in Patent Document 1 (conventional structure), there was a high risk of the water seal of the drain hose 178 being broken. However, in this embodiment, by providing an overflow solenoid valve 182 in the overflow path 180, the pressure resistance performance of the overflow path 180 is improved, thus achieving both improved drying finish and prevention of the water seal of the drain hose 178 being broken.

[0052] (Key Feature 5) Furthermore, in this embodiment, by adopting a heat pump system, which has higher thermal efficiency than a heater system, as the drying method, power consumption is reduced, and by operating with high heating capacity and high dehumidification speed, both time savings and energy savings are achieved. Also, as shown in Figure 2, by installing the heat pump unit 220, which performs heating and dehumidification, below the outer tub 130, the dead space on the lower rear side of the outer tub 130 can be effectively utilized, making it easier to enlarge the heat pump unit 220, and further time savings can be expected by improving the dehumidification speed. Moreover, even when the heat pump unit 220 is enlarged to achieve a high level of both time savings and energy savings, the position of the rotating drum 140, i.e., the clothing loading area, is raised, making it easier to load clothes, and thus improving usability can be expected.

[0053] Furthermore, as shown in Figures 2 and 13, when the heat pump unit 220 is installed below the outer tank 130, the dehumidified water removed by the dehumidifier 233 is stored at the bottom of the heat pump unit 220. Therefore, the heat pump unit 220 needs to be equipped with a condensation water pump 250 to drain the dehumidified water to the drain port 190 via the condensation water hose 252. When the condensation water pump 250 is driven, the dehumidified water flows towards the drain hose 178, and the air near the connection point 192 between the condensation water hose 252 and the drain hose 178 is pressurized by the drainage. Therefore, if there is residual water in the condensation water hose 252 when the condensation water pump 250 is stopped, the high-pressure air near the connection point 192 between the condensation water hose 252 and the drain hose 178 pushes the residual water in the condensation water hose 252, and then it flows back into the heat pump unit 220 due to the siphon effect. When such a siphon phenomenon occurs, the area near the connection point 192 between the condensation water hose 252 and the drain hose 178, that is, the downstream side of the overflow solenoid valve 182, becomes negatively pressurized by the head difference of the condensation water hose 252. In this embodiment, since the height 191 of the condensation water hose is set to 500 mm, the downstream side of the overflow solenoid valve 182 temporarily becomes negatively pressurized by the head difference of the condensation water hose 252, Ph = 490 Pa. Thus, in order to obtain the time-saving effect by installing the heat pump unit 220 below the outer tank 130, a problem arises in that the water seal of the drain hose 178 is more likely to come loose than when the heat pump unit 220 is installed above the outer tank 130. In the case where a U-shaped drain trap is installed in the overflow path as described in Patent Document 1 (conventional structure), there was a high risk of the water seal of the drain hose 178 coming loose. However, in this embodiment, by installing an overflow solenoid valve 182 in the overflow path 180, the pressure resistance performance of the overflow path 180 is improved, so that the time-saving effect and the prevention of the water seal of the drain hose 178 coming loose can be achieved at the same time.

[0054] (Key Feature 6) Furthermore, by configuring the washing and drying machine 100 so that the pressure relationships are Pr1 > Pdmax + Ph and Pr2 > Pdmax + Ph, it becomes more reliable to prevent the water seal in the drain hose 178 from leaking.

[0055] (Filter structure and water film) Figure 17 shows the shape of the mesh portion of the filter. In this embodiment, the mesh portion (lint collection portion) of the primary filter 152 and the secondary filter 154 has the same shape, with a wire diameter d of 0.1 mm and a mesh opening w of 0.182 mm, and is constructed by weaving together SUS mesh.

[0056] Figures 18A to 18C are excerpts of sections of cross-section AA in Figure 17, respectively. Figure 18A shows the state in which a water film 301 is attached to the filter 300. Figure 18B shows the state in which a water film 301 is attached to the filter 300 and the internal pressure Pd of the outer tub 130 has increased. Figure 18C shows the state in which a water film 301 and lint are attached to the filter 300 and the internal pressure Pd of the outer tub 130 has increased. The primary filter 152 and the secondary filter 154 are washed in the washing and dewatering process, so the water film 301 is held on the mesh by capillary force determined by the surface tension σ of the water and the mesh opening w of the filter (see Figure 18A). The water film 301 held on the mesh deforms due to the increase in internal pressure of the outer tub 130 during the drying operation (see Figure 18B), and the capillary force decreases due to the deformation. Subsequently, the water film 301 is broken by pressure exceeding the capillary force, and the drying operation begins.

[0057] Furthermore, even if the mesh portions of the primary filter 152 and secondary filter 154 are washed with cleaning water, repeated use can cause the accumulation of minute lint. Since lint is generally hydrophilic and often becomes firmly entangled in the filter 300, the connection between the filter 300 and the water film 301 also becomes strong. Therefore, if even minute amounts of lint adhere to the filter 300 when the water film 301 is formed, the water film 301 will not deform even if the internal pressure of the outer tank 130 increases during operation (see Figure 18C). In other words, in the state shown in Figure 18C, the water film does not deform, so the capillary force is greater than in the state shown in Figure 18B, and the force required to break the water film 301 is also greater. In short, if lint adheres to the filter 300, it becomes more difficult to break the water film 301.

[0058] Figure 19 shows the relationship between the secondary filter opening ratio and the capillary force of the water film formed on the filter. The horizontal axis represents the secondary filter opening ratio, which is dimensionless based on the clogging state of the secondary filter 154, and the vertical axis represents the capillary force of the filter and the internal pressure (static pressure) of the outer tank 130 when the water film 301 is broken. The plots show the experimental results of the internal pressure (static pressure) of the outer tank 130 when the water film 301 is broken, and the dotted line shows the calculated results of the capillary force. The calculation results simulate the state in which the water film does not deform (Figure 18C) in equation (1) described later, where θ=α=0. Also, the surface tension σ=0.0728 [N / m].

[0059] The capillary force Pc, that is, the force with which filter 300 holds the water film 301, can be calculated using the following formula (1), where α [rad] is the water film retraction angle, θ [rad] is the contact angle, d [m] is the wire diameter of filter 300, w [m] is the mesh opening of filter 300, σ [N / m] is the surface tension of water, and s [%] is the filter opening ratio (see Figure 18B).

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[0060] As shown in Figure 19, under the condition of a 100% opening ratio for the primary filter 152 and secondary filter 154, the internal pressure of the outer tank 130 that drives the blower 210 to break the water film is approximately 700 Pa, meaning that the capillary force Pc of the water film 301 was 700 Pa. Furthermore, using equation (1), if we calculate the capillary force so that the experimental and calculated values ​​match, assuming α = θ / 2, we find that θ ≈ 80° and α ≈ 40°, which is a value greater than zero. Substituting θ = α = 0 into equation (1) and solving, we get Pc = 1370 Pa. Therefore, in the state of a 100% opening ratio with no lint attached to the primary filter 152 and secondary filter 154 and only a water film attached, it can be seen that the capillary force decreases as the water film 301 deforms, and then the water film 301 breaks.

[0061] Next, focusing on the results for secondary filter aperture ratios other than 100%, we can see that the experimental results and the calculated results (θ=α=0) agree well. From this, we can see that when the secondary filter aperture ratio is less than 100%, especially less than 80%, the water film 301 ruptures without deformation. Furthermore, as lint adheres to the secondary filter 154, the secondary filter aperture ratio gradually decreases, and this increases the capillary force. Also, the capillary force Pc when the secondary filter aperture ratio is less than 80% can be expressed by equation (2) by substituting θ=α=0 into equation (1). In the unlikely event that the secondary filter aperture ratio is halved to 50%, the capillary force Pc can be expressed by equation (3).

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[0062] (Key Feature 7) Based on the above characteristics, in this embodiment, even if the secondary filter opening ratio is halved (50%), the internal pressure of the outer tank 130 is increased by driving the blower 210, which breaks the water film 301 formed on the filter 300 at the start of drying, allowing air to circulate. Furthermore, even if the internal pressure of the outer tank 130 is increased to break the water film 301, the pressure relationship is such that the water seal of the drain hose 178 is not broken. The pressure relationship when the secondary filter opening ratio is 50% will be explained below using Figure 20.

[0063] Figure 20 shows the relationship between the secondary filter opening ratio, the internal pressure of the outer tank, and the capillary force of the filter. Figure 20 shows the maximum rotational speed of the blower 210 at 10,000 min⁻¹ during standard operation in drying operation. -1 The solid line shows the internal pressure (static pressure) of the outer tank 130 when driven by the system, the dotted lines show the pressure resistance Pr1 of the drain solenoid valve 176 and the pressure resistance Pr2 of the overflow solenoid valve 182, and the dashed line shows the calculated result of the capillary force Pc50 when the secondary filter opening ratio is reduced to 50%.

[0064] As shown in Figure 20, if the secondary filter opening ratio becomes 50%, the internal pressure of the outer tank 130 will be Pd50 = approximately 1300 Pa. However, if the blower 210 is driven while a water film 301 is formed on the filter 300, the filter 300 will act like a wall, that is, the same as when the secondary filter opening ratio is 0%, and circulating air will not flow. As a result, the internal pressure (static pressure) Pd of the outer tank 130 will rise to its maximum value, Pdmax = 3000 Pa. Here, the capillary force of the water film 301 held on the filter 300 is Pc50 = 6.86σ / w = 2742 Pa. Therefore, since Pdmax > Pc50, the water film 301 will break, and the drying operation will begin. Once the water film 301 breaks, the internal pressure of the outer tank 130 will gradually decrease to Pd50. Furthermore, although the internal pressure of the outer tank 130 temporarily increases during the process of breaking the water film 301, the water seal of the drain hose 178 is prevented from being broken by setting the pressure resistance Pr1 and pressure resistance Pr2 of the drain solenoid valve higher than Pdmax. Note that although Figure 20 shows the case where the secondary filter opening ratio is 50%, the same results are obtained even when the primary filter opening ratio is 50%.

[0065] As described above, in this embodiment, in a washing and drying machine that washes the drying filter (primary filter 152 or secondary filter 154) with water, the pressure resistance Pr1 of the drain solenoid valve and the pressure resistance Pr2 of the overflow solenoid valve are higher than the maximum static pressure Pdmax inside the outer tub when the drying filter is completely clogged, at the maximum rotational speed of the blower 210 during standard operation when drying, and Pdmax is higher than the capillary force of 6.86σ / w when the drying filter is 50% clogged. Since the relationships Pr1>Pdmax>6.86σ / w and Pr2>Pdmax>6.86σ / w hold true, even in a washer-dryer that improves usability by automatically cleaning the drying filter with water flow, the internal pressure (static pressure) of the outer tub 130 can be increased to break the water film 301 formed on the filter 300 and start the drying operation. Furthermore, even if the internal pressure (static pressure) of the outer tub 130 increases due to the water film 301, the water seal of the drain hose 178 can be prevented from breaking. In other words, it is possible to achieve both improved usability through automatic cleaning of the drying filter and prevention of water seal breakdown in the drain hose 178 without extending the drying time or reducing energy efficiency.

[0066] [Differentiation] The present invention is not limited to the embodiments described above, and various modifications are possible. The embodiments described above are illustrative examples provided to facilitate understanding of the present invention, and are not necessarily limited to those comprising all the configurations described. Furthermore, other configurations may be added to the configurations of the above embodiments, and some of the configurations may be replaced with other configurations. [Explanation of Symbols]

[0067] 100 Washer-Dryer 130 Outer tank 140 RPM drum (inner tub) 152 Primary filter (drying filter) 154 Secondary filter (drying filter) 156 Return wind path 160 Drainage routes 176 Drain Solenoid Valve 180 Flood Paths 182 Overflow Solenoid Valve 190 Drain 211 Blower 220 Heat Pump Unit 223,224 Intake ports 231 Compressor 232 Heater (Condenser) 233 Dehumidifier (Evaporator) 235 Expansion valve (expansion mechanism) 310,320,330 Discharge air path 340 Discharge port 223 Air intake 300 filters 301 Water film

Claims

1. Outer tank and A heater and Dehumidifier and The discharge air passage through which the air blown from the blower flows, A discharge port connected to the aforementioned discharge air passage and which blows air into the outer tank, A return air passage that returns air from the outer tank to the blower, A drying filter to catch lint generated from clothing, An air intake port is provided between the outer tank and the blower, The system includes a drainage path and an overflow path connecting the outer tank and the drain outlet, A drainage solenoid valve and an overflow solenoid valve are provided in the drainage path and the overflow path, respectively. A washing machine and dryer characterized by the following features.

2. In the washing and drying machine according to claim 1, If the pressure resistance of the drain solenoid valve is Pr1, the pressure resistance of the overflow solenoid valve is Pr2, and the maximum static pressure inside the outer tank when the drying filter is completely clogged at the maximum rotation speed of the blower during standard operation during drying is Pdmax, then the pressure relationships Pr1 > Pdmax and Pr2 > Pdmax hold true. A washing machine and dryer characterized by the following features.

3. In the washing and drying machine according to claim 1, The aforementioned discharge port is located on the front side of the washing machine / dryer. A washing machine and dryer characterized by the following features.

4. In the washing and drying machine according to claim 1, The aforementioned discharge port has the smallest cross-sectional area in the airflow path. A washing machine and dryer characterized by the following features.

5. In the washing and drying machine according to claim 1, Between the return air passage and the blower, there is a heat pump unit that performs dehumidification and heating, and the heat pump unit is equipped with a condensation water pump that discharges the dehumidified water. A washing machine and dryer characterized by the following features.

6. In the washing and drying machine according to claim 5, The condensation water pump is connected to the drain hose downstream of the overflow solenoid valve via a condensation water hose, and the pressure relationships Pr1 > Pdmax + Ph and Pr2 > Pdmax + Ph hold when the head difference of the condensation water hose is Ph. A washing machine and dryer characterized by the following features.

7. In the washing and drying machine according to claim 1, The structure includes a mechanism for washing the aforementioned drying filter with a water flow. When the mesh opening of the filter is w and the surface tension of water is σ, the relationships Pr1 > Pdmax > (6.86σ / w) and Pr2 > Pdmax > (6.86σ / w) hold true. A washing machine and dryer characterized by the following features.

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