Washing machine

Abstract

To provide a washing machine capable of performing washing suited for the amount of laundry.SOLUTION: A washing machine S includes: an inner tub 4 in which laundry e is stored, and which rotates; a motor 4m for rotationally driving the inner tub 4; an outer tub 3 in which washing water is stored; a circulation flow passage 9 for circulating the washing water in the outer tub 3; a circulation pump 8a for delivering the washing water in the outer tub 3 to the circulation flow passage 9; and a control device 19 for taking charge of control. The circulation flow passage 9 includes a plurality of discharge ports 10a, 10b in which the heights to discharge the washing water to the laundry are different. In the case where the amount of the laundry e is small, the circulation pump 8a is operated at a low rotation speed A2 compared to the case where the amount of the laundry e is large.SELECTED DRAWING: Figure 8

Description

[Technical field]

[0001] The present invention relates to a washing machine. [Background technology]

[0002] In a drum-type washing machine, in order to effectively utilize the washing water in the washing process, a method is known in which the washing liquid is lifted into the drum tub by a circulation pump and sprinkled on the clothes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6966494 Summary of the Invention [Problem to be solved by the invention]

[0004] When the circulation pump is used to spray the laundry with the washing liquid, if the water level in the outer tub is low, the circulation pump will run idle even if the rotation speed is increased, making it difficult to spray a sufficient amount of washing liquid. Also, if the rotation speed of the circulation pump is increased, the washing liquid may foam, which may reduce the washing performance.

[0005] In addition, when using a hot water heater to heat the washing liquid, if the water level in the outer tub is low, the hot water heater is exposed when the circulation pump is operating, and the machine is prone to running dry. This makes it difficult to reduce the amount of water used during hot water washing, and makes it difficult to wash with a high concentration of detergent solution.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a washing machine capable of performing washing with high washing performance according to the amount of laundry. [Means for solving the problem]

[0007] In order to solve the above problem, the washing machine of the present invention comprises an inner tub in which laundry is stored and which rotates, a motor which drives and rotates the inner tub, an outer tub in which wash water is stored, a circulation flow path which circulates the wash water in the outer tub, a circulation pump which sends the wash water in the outer tub to the circulation flow path, and a control device which performs control, the circulation flow path having a plurality of outlets at different heights which discharge the wash water onto the laundry, and the circulation pump which is operated at a lower rotation speed when there is a small amount of laundry compared to when there is a large amount of laundry. Effect of the Invention

[0008] According to the present invention, a washing machine capable of performing washing with high washing performance according to the amount of laundry can be provided. [Brief description of the drawings]

[0009] [Figure 1] 1 is a perspective view of a washing / drying machine according to an embodiment of the present invention, viewed obliquely from above and in front; [Diagram 2] FIG. 2 is a central cross-sectional view of the washer-dryer of FIG. 1 as viewed from the left side. [Diagram 3] FIG. [Figure 4] Schematic diagram of the outer tank, rotating drum, circulation pump, and the lower and upper outlets of the circulation flow path, as viewed from the front. [Diagram 5] FIG. 2 is an exploded perspective view showing the tub cover removed from the outer tub and the rotating drum and outer tub partially cut away. [Figure 6] FIG. 2 is a block diagram showing the configuration of a control device of the washer / dryer. [Figure 7] A flow chart outlining the washing and drying processes. [Figure 8] 11 is a flowchart showing the control of the main washing process. [Figure 9] 13 is a flow chart for controlling the main washing process in warm water. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a perspective view of a washer / dryer S according to an embodiment of the present invention, as viewed obliquely from above and in the front.

[0011] <Case 1> The washer / dryer S has a skeleton (not shown) formed on the upper part of a base 1b by combining side panels 1s made mainly of steel plates and resin molded parts with reinforcing materials (not shown). A front cover 1z and a top cover 1j are attached onto the skeleton to form a housing 1. The front cover 1z is provided with a door 2 for inserting and removing laundry e. At the front upper portion of the door 2, a power switch, an operation switch b1 for selecting an operation mode, and a display b2 are provided.

[0012] <Outer tank 3 and rotating drum 4> FIG. 2 shows a central cross-sectional view of the washer / dryer S of FIG. 1 as viewed from the left side. An outer tub 3 for storing wash water is provided inside the housing 1. The outer tub 3 is supported by a number of suspensions (not shown) fixed to the base 1b. A tension spring (not shown) that engages with the framework is attached to the upper part of the outer tub 3. The tension spring prevents the outer tub 3 from falling over.

[0013] A rotating drum (inner tub) 4 is rotatably supported inside the outer tub 3. A user opens the door 2 and places laundry e into the rotating drum 4. The rotating drum 4 has many small holes 4k (see FIG. 5) formed on the side and back for centrifugal dehydration and ventilation. In addition, a fluid balancer 5 for reducing vibrations caused by imbalance of the laundry e during spin-drying is provided on the outer periphery of the opening 4i of the rotating drum 4. The fluid inside the fluid balancer 5 moves to the opposite side of the imbalance of the laundry e to suppress vibrations.

[0014] A plurality of lifters 4a (see FIG. 2) that lift up the laundry e and beat the laundry e are provided inside the rotating drum 4. The rotating drum 4 is directly connected to a drum driving motor (drive unit) 4m via a metal flange 4f and a main shaft 4j. The main shaft 4j is connected to the metal flange 4f of the rotating drum 4.

[0015] A tub cover 3c is provided at the front of the outer tub 3. An elastic rubber bellows 3b is attached to an opening 3c1 of the tub cover 3c. The bellows 3b flexibly deforms to maintain watertightness between the outer tub 3 and the door 2. The bellows 3b prevents water from leaking from the outer tub 3 during washing, rinsing and spin-drying. A water receiving section 3u (see FIG. 2) is provided at the bottom of the outer tub 3. A drainage path 6 is provided below the outer tub 3.

[0016] <Drainage route 6> FIG. 3 shows the configuration of the drainage path 6. The washer / dryer S is provided with a drainage path 6 and an overflow path 7. The drainage path 6 is a path for draining water accumulated in the outer tub 3. The overflow path 7 is a path for overflow drainage when the water accumulated in the outer tub 3 exceeds a predetermined water level.

[0017] The drainage path 6 is configured to include an internal drainage channel 6a, a water channel filter 6b, a drain valve 6c, and a drain hose 6d. The internal drainage channel 6a is connected to the bottom surface 3t (see FIG. 2) of the outer tub 3. The water channel filter 6b collects lint (lint) generated from the laundry e being drained through the internal drainage channel 6a. The lint collected by the water channel filter 6b is cleaned up by the user as appropriate.

[0018] Water can pass through and be stored in the overflow path 7. The overflow path 7 is also capable of blocking the flow of air by storing water, and is equipped with a trap 7a that replaces the seal water by supplying water with the rotation of the rotating drum 4. The overflow path 7 downstream of the trap 7a communicates with a drain hose 6d. A condensation water hose 7c is connected to the downstream side of the drain hose 6d for draining the water dehumidified by the heat pump unit Hu by means of a condensation water pump 7b.

[0019] The condensation water hose 7c is elevated to a position higher than the overflow path 7 in the vertical direction in order to prevent backflow from the drain hose 6d to the heat pump unit Hu.

[0020] FIG. 4 shows a schematic diagram of the outer tank 3, the rotary drum 4, the circulation pump 8a, and the lower discharge port 10a and upper discharge port 10b of the circulation flow path 9 as viewed from the front. FIG. 5 shows an exploded perspective view of the outer tub 3 with the tub cover 3c removed and the rotating drum 4 and the outer tub 3 partially cut away.

[0021] 5 shows a state in which a part of the right side surface of the outer tub 3 and a part of the right side surface of the rotating drum 4 are cut away. Between the water channel filter 6b and the outer tub 3 shown in FIG. 3, a circulation water channel 8 for circulating the water in the outer tub 3 through a circulation flow channel 9 (see FIG. 4), and a circulation pump 8a are provided.

[0022] <Circulation flow path 9> The outer tub 3 shown in Fig. 5 is composed of a cylindrical outer tub body 3h with a bottom, and a tub cover 3c provided at a front opening 3h1 of the outer tub body 3h. The tub cover 3c is formed with a circulation flow path 9 (see Figs. 4 and 5) through which the washing water pumped up by the circulation pump 8a (see Fig. 3) passes. A lower discharge port 10a is formed at the bottom of the circulation flow path 9. An upper discharge port 10b is formed at the top of the circulation flow path 9. The tub cover 3c is formed with a discharge air passage 3c2 through which dry air flows, and an outlet 3c3 through which dry air is blown into the rotating drum 4.

[0023] A circulation water passage 8 is connected to the circulation flow path 9. As a result, water in the outer tub 3 is supplied to the clothes (laundry e) in the rotating drum 4 from the lower outlet 10a or the upper outlet 10b by using a circulation pump 8a. The water supplied to the circulation water passage 8 is sprayed (supplied) onto the clothes (laundry e) in the rotating drum 4 from the lower outlet 10a, or from the lower outlet 10a and the upper outlet 10b.

[0024] 4, a water level sensor 11 for measuring the water level of the outer tub 3 is provided near the outer tub 3. In addition, a hot water heater 12 for heating the wash water in the outer tub 3 is provided above the water receiving portion 3u of the outer tub 3.

[0025] <Control device 19> FIG. 6 shows a block diagram of the configuration of the control device 19 of the washer / dryer S. The control device 19 includes a microcomputer (hereinafter referred to as "microcomputer") 110. The microcomputer 110 acquires various information signals (such as signals from the water level sensor 11, the drain temperature sensor T1, the temperature sensor T2, the temperature sensor T3, the outside air temperature sensor T4, and the electrical conductivity sensor 14) in response to the user's operation of the operation switch b1 (see FIG. 1) and in the washing and drying processes.

[0026] The microcomputer 110 is also connected via drive circuits to the motor 4m, the water supply solenoid valve 16, the drain valve 6c (see FIG. 3), the circulation pump 8a, the blower fan 22, the compressor 307, the variable expansion valve 308, the drain pump 312, the variable exhaust means 306, the hot water heater 12, etc. The microcomputer 110 controls the opening / closing operation, the rotation operation, and the energization of these components. A current sensor such as a resistance detection type is incorporated in the drive circuit 4m1 of the motor 4m. Microcomputer 110 also controls a display b2 (see FIG. 1), a buzzer (not shown), etc. to inform the user of information related to washer / dryer S. Microcomputer 110 also includes an operation pattern database 111, a process control unit 112, a rotation speed calculation unit 113, a clothes weight calculation unit 114, an electrical conductivity measurement unit 115, a detergent amount / washing time determination unit 116, a turbidity determination unit 117, and a threshold value storage unit 118. Microcomputer 110 starts up when a power switch (not shown) is pressed to turn on the power, and executes basic control processing programs for washing and drying, which will be described later.

[0027] <Overview of control method> As shown in FIG. 4, the circulation pump 8a is provided with two outlets, an upper outlet 10b and a lower outlet 10a. With this configuration, depending on the amount of laundry e, the washing process is carried out by selectively using both the lower discharge outlet 10a and the upper discharge outlet 10b as a shower outlet for the laundry e (see FIG. 2) or by using only the lower discharge outlet 10a as a shower outlet for the laundry e.

[0028] The shower outlet is switched by the rotation speed of the circulation pump 8a. For example, when the amount of laundry e is small and the water level w1 (see FIG. 4) is low, or when washing with warm water, the rotation speed of the circulation pump 8a is reduced and the washing liquid is discharged onto the laundry e only from the lower discharge port 10a. On the other hand, when the amount of laundry e to be discharged is large and the water level w2 (see FIG. 4) is high, the rotation speed of the circulation pump 8a is increased to discharge the washing liquid onto the laundry e from the lower discharge port 10a and the upper discharge port 10b.

[0029] The rotation speed of the circulation pump 8a during the main wash process is determined based on the value of the sensing of the amount of clothes (laundry e). The amount of clothes (laundry e) is sensed at the start of the wash process by estimating the amount of clothes (laundry e) from the current value that represents the magnitude of torque when the motor 4m rotates the rotating drum 4 with clothes in it. Since the current value and torque value of the motor 4m are proportional to each other, the amount of clothes (laundry e), which determines the magnitude of torque, can be found by obtaining the current value.

[0030] When the amount of laundry is large, in order to promote the penetration of the laundry with the laundry liquid, the circulation pump 8a is set to a rotation speed at which the laundry liquid is discharged from both the upper discharge outlet 10b and the lower discharge outlet 10a shown in FIG. 4 (for example, 2100 rpm). When the amount of laundry is small (for example, when the amount of laundry is less than 30% or less than 24% to 36% of the rated capacity (when the amount of laundry is less than the threshold value M2 described below and exceeds the threshold value M1)), the rotation speed of the circulation pump 8a is set lower than when the amount of laundry is large, and washing liquid is discharged only from the lower discharge outlet 10a (for example, 1900 rpm).

[0031] When the amount of laundry is very small (for example, less than 2 kg (when the amount of laundry is less than the threshold value M1 described below)), the detergent concentration becomes high and the risk of foaming increases, so the detergent solution is circulated at an even lower rotation speed (for example, 1700 rpm). In the warm water washing process, when the amount of laundry is small and the water level is low, the rotation speed of the circulation pump 8a is set lower than when the amount of laundry is large in order to reduce the risk of the hot water heater 12 (see FIG. 4) heating without water. This prevents the washing liquid from flying up.

[0032] <Overview of the washing and drying process> Next, an overview of the control of the washing / drying machine S from the washing process to the drying process will be described. Figure 7 shows a flowchart outlining the washing and drying processes. The washer / dryer S is controlled by a control device 19 (see FIG. 6). When washing, the user opens the door 2 (see FIG. 2), puts the laundry e to be washed into the rotating drum 4, and closes the door 2. Then, the user operates the operation switch b1 (see FIG. 1) to select a course of the operation process.

[0033] This causes the control device 19 to accept an input for selecting a course of operation for the washer / dryer S (course selection). Based on the input course of operation, the control device 19 reads a corresponding operation pattern from the operation pattern database 111 (see FIG. 6). In the following description, it is assumed that the standard course of washing and drying (wash-rinse twice-spin-dry) has been selected.

[0034] In step S1 of Fig. 7, the control device 19 executes a process of detecting the weight (clothing amount) of the laundry e (see Fig. 2) put into the rotating drum 4 (clothing amount sensing). Specifically, the process control unit 112 (see Fig. 6) drives the motor 4m to rotate the rotating drum 4, and the clothing weight calculation unit 114 (see Fig. 6) calculates the weight of the laundry (clothing amount) before water is poured from the current of the motor 4m.

[0035] In step S2, the control device 19 executes a process for calculating the amount of detergent and the operation time, and the water supply solenoid valve 16 is opened to supply water according to the amount of clothes. After that, the conductivity measurement unit 115 detects the conductivity (hardness) of the supplied water. Also, the temperature of the supplied water is detected by a drain temperature sensor T1 provided at the bottom of the outer tub 3 (for example, at the drain outlet 3o (see FIG. 2)). The detergent amount / washing time determination unit 116 determines the amount of detergent to be dispensed and the operation time by map search based on the detected amount of clothes, the water conductivity (hardness) obtained by the conductivity measurement unit 115 using the detection value from the conductivity sensor 14, and the water temperature. Then, the process control unit 112 displays the determined amount of detergent and operation time on the display b2 (see FIG. 1).

[0036] The control device 19 waits for a predetermined time (detergent input waiting process). The user inputs detergent into the detergent input section (not shown) while waiting, referring to the amount of detergent displayed on the display b2. If automatic detergent input is set, the detergent input operation is omitted. The washing process is broadly divided into a pre-washing process (step S3) and a main washing process (step S4). The control device 19 executes a detergent dissolving process before the pre-washing process (step S3). The water supply solenoid valve 16 is opened to supply water. The water is introduced into the detergent inlet and then poured into the outer tub 3. The detergent liquid poured into the outer tub 3 is supplied to the water receiving section 3u (see FIG. 2) located at the bottom of the rotating drum 4 through a water supply path (not shown). After the detergent liquid is poured in, the circulating pump 8a (see FIG. 3) is driven in the reverse rotation direction to agitate the supplied detergent liquid.

[0037] When the circulation pump 8a (see FIG. 3) is driven in the forward direction, the water in the water receiving section 3u flows from the drain port 3o (see FIG. 2) through the lint filter water channel filter 6b (see FIG. 3) into the suction port (not shown) of the circulation pump 8a. The wash water pressurized by the circulation pump 8a passes through the circulation water channel 8 communicating with the outlet of the circulation pump 8a, the lower discharge port 10a of the circulation flow channel 9, and the upper discharge port 10b, before returning to the water receiving section 3u (see FIG. 2).

[0038] At this time, the control device 19 detects the conductivity using the conductivity sensor 14 in the water receiving section 3u, and compares it with the conductivity database for the high-concentration detergent aqueous solution and the conductivity database for the fabric softener aqueous solution. By repeatedly circulating the laundry liquid using the circulation flow path 9, a uniform high-concentration detergent liquid is produced in which the detergent is dissolved in a small amount of water. Then, the rotating drum 4 is rotated to agitate the laundry e, and the detergent liquid pumped up through the circulation flow path 9 (see Figures 4 and 5) by the circulation pump 8a is sprayed evenly onto the laundry e from the lower outlet 10a and upper outlet 10b or the lower outlet 10a of the sprinkler nozzle.

[0039] In step S3, the control device 19 executes a pre-washing process. In the pre-washing process, the laundry e soaked in detergent liquid is usually present in the outer tub 3, and a small amount of detergent liquid is present in the water receiving portion 3u at the bottom of the outer tub 3. By rotating the rotary drum 4, the laundry e is lifted to the top of the rotary drum 4, and then beaten by a tumbling action in which the laundry e falls to the bottom by gravity. As a result, the detergent liquid soaked in the laundry e is squeezed out, and the circulation pump 8a is driven intermittently as necessary to spray the detergent liquid on the laundry e again.

[0040] In step S4, the main washing step is carried out. FIG. 8 shows a flow chart of the control of the main washing process. In step S11 of FIG. 8, it is determined whether the read value of the water level sensor 11 is equal to or greater than the water level value Tr corresponding to the amount of clothes. When the reading of the water level sensor 11 (see FIG. 4) is less than the water level value Tr corresponding to the amount of clothes, the water supply solenoid valve 16 is opened to supply water (step S12 in FIG. 8).

[0041] Next, in step S13, it is determined whether the amount of clothes (laundry e) is greater than a small amount threshold M1. As the thresholds for the amount of laundry e, a threshold M1 for a small amount of laundry e and a threshold M2 for a rated capacity amount of laundry e are preset in the threshold storage unit 118 (see FIG. 6). If the amount of laundry e is not greater than the small amount threshold M1 (No in step S13), the circulation pump 8a is set to the lowest rotation speed A3 in step 14. That is, if the amount of laundry e is even smaller (very small amount) than when the amount of laundry e is small (small amount), that is, if the amount of laundry e is equal to or less than the threshold M1 (No in step S13), the circulation pump 8a is operated at an extremely low rotation speed (the lowest rotation speed A3) which is even lower than when the amount of laundry e is small. Note that when the amount of laundry e is even smaller (very small amount), the amount of laundry e is less than the threshold value M1, for example, a volume of 2 kg or less.

[0042] If the amount of clothes e is greater than the small amount threshold M1 (Yes in step S13), then in step S15 it is determined whether the amount of clothes (laundry e) is greater than the rated threshold M2. If the amount of laundry e is not greater than the rated capacity threshold M2 (No in step S15), in step S16, the circulation pump 8a is set to a low rotation speed A2. If the amount of laundry e is greater than the rated capacity threshold M2 (Yes in step S15), in step S17, the rotation speed of the circulation pump 8a is set to A1.

[0043] In this way, the rotation speed of the circulation pump 8a is set to the rotation speed A3 when the amount of laundry is very small (less than M1; No in step S13). If the amount of clothes is equal to or less than the rated capacity (M2 or less; No in step S15), the rotation speed A2 is set as the default. When the amount of clothes is the rated capacity (i.e., when it exceeds threshold value M2 (>M2; Yes in step S15 of Figure 8), rotation speed A1 is preset. In other words, the rotation speeds A1, A2, and A3 of the circulation pump 8a have the relationship A1>A2>A3. In this way, when the amount of clothes is small, power consumption can be reduced by lowering the rotation speed of the circulation pump 8a to A2 or A3.

[0044] Next, in step S18, the rotating drum 4 is rotated by the motor 4m, and the circulation pump 8a is operated at the rotation speed A3, A2, or A1 to circulate the washing liquid, and the clothes (laundry e) in the rotating drum 4 are beaten while being agitated. In this way, when the amount of laundry is very small (e.g., 2 kg or less), the detergent concentration becomes high and the risk of foaming increases, so the laundry liquid is discharged only from the lower outlet 10a at an even lower rotation speed A3 (e.g., 1700 rpm), and the detergent liquid is circulated to perform a beating wash.

[0045] When the amount of laundry is equal to or less than the rated capacity threshold value M2 (No in step 15 of FIG. 8), the rotation speed A2 of the circulation pump 8a is set to a lower speed (e.g., 1900 rpm) than when the amount of laundry is large, and laundry liquid is discharged only from the lower outlet 10a, detergent liquid is circulated, and beating wash is performed. If the amount of laundry exceeds the rated capacity threshold M2 (if the answer is Yes in step 15 of FIG. 8), the rotation speed A1 (e.g., 2100 rpm) of the circulation pump 8a is set, and laundry liquid is discharged from both the upper outlet 10b and the lower outlet 10a to promote absorption of the laundry liquid, and the laundry is beaten.

[0046] Then, in step S19, it is determined whether or not the main wash operation time has elapsed. If the wash operation time has not elapsed (No in step S19), the main wash continues. If the main washing operation time has elapsed (Yes in step S19), the main washing process is ended. By the above-mentioned main washing process, even when there is a small amount of clothes (laundry e) and the amount of washing water is small, detergent liquid can be supplied from the lower discharge port 10a and washed while circulating the detergent liquid. Also, even when there is only a small amount of clothes (laundry e), the circulation pump 8a can be driven at an even lower rotation speed A1 (for example, 1700 rpm) to rotate the rotating drum 4 at a very slow speed, thereby suppressing foaming.

[0047] This allows the detergent liquid to be sprayed onto clothes at a high detergent concentration, leading to improved cleaning performance. <Control of the main washing process in warm water>

[0048] FIG. 9 shows a flow chart for controlling the main washing process in warm water. In step S21 of FIG. 9, it is determined whether the read value of the water level sensor 11 is equal to or greater than the water level value Tr corresponding to the amount of clothes. If the reading from the water level sensor 11 is less than the water level value Tr (No in step S21), the water supply solenoid valve 16 is opened to supply water (step S22 in FIG. 9). If the reading from the water level sensor 11 is equal to or greater than the water level value Tr (Yes in step S21), then in step S23 it is determined whether the amount of clothes (laundry e) is greater than the rated capacity threshold M1.

[0049] If the amount of clothes (amount of laundry e) is not greater than the rated capacity threshold M1 (No in step S23), in step S24 the rotation speed of the circulation pump 8a is set to A2 for a small amount of clothes. If the amount of laundry (amount of laundry e) is greater than the rated capacity threshold M1 (Yes in step S23), the rotation speed A1 of the circulation pump 8a is set when the amount of laundry is at the rated capacity in step 25. The relationship between the rotation speeds A1 and A2 of the circulation pump 8a is A1>A2.

[0050] Next, in step S26, the hot water heater 12 (see FIG. 4) is turned ON. Next, in step S27, the rotating drum 4 is rotated by the motor 4m until a predetermined time has elapsed, and the laundry liquid is circulated from the lower outlet 10a and the upper outlet 10b of the circulation flow path 9 when the circulation pump 8a is rotating at a rotation speed A1, or the laundry liquid is circulated from the lower outlet 10a of the circulation flow path 9 when the circulation pump 8a is rotating at a rotation speed A2, and the laundry is agitated and beaten.

[0051] In step S28, it is determined whether the temperature of the washing liquid in the outer tub 3 measured by the temperature sensor T2 is equal to or higher than the target temperature. If the water temperature has not reached or exceeded the target temperature (No in step S28), the current state is continued. If the water temperature has reached or exceeded the target temperature (Yes in step S28), the hot water heater 12 (see FIG. 4) is turned off in step S29.

[0052] In step S30, the microcomputer 110 determines whether or not the main wash operation time has elapsed based on the data in the detergent amount / wash time determination unit 116 and the threshold value storage unit 118. If the main wash operation time has not elapsed (No in step S30), the process proceeds to step S27. If the main washing operation time has elapsed (Yes in step S30), the main washing process ends. In the above-mentioned warm water washing course, the amount of water can be reduced and the detergent solution can be heated in a short time, thereby achieving the effects of saving water, time and energy.

[0053] Next, a rinsing step (step S5) and a spin-drying step (step S6) shown in FIG. 7 are carried out. In step S7 of FIG. 7, it is determined whether or not the washing and drying operation is being performed. If the washing and drying operation is not performed (No in step S7), the process ends. If the washing and drying operation is to be performed (Yes in step S7), the drying step is performed in step S8, and the process ends.

[0054] According to the above configuration, when the circulation pump 8a is used to spray laundry liquid onto the clothes, if the water level in the outer tub 3 is low, the rotation speed of the circulation pump 8a can be set low so that an appropriate amount of laundry liquid can be sprayed onto the clothes from the lower outlet 10a (see Figures 4 and 5). In addition, when there is only a small amount of laundry, the rotation speed of the circulation pump 8a is further reduced and the laundry liquid is supplied from the lower discharge port 10a (see Figure 4), so that the laundry liquid does not foam and deterioration of cleaning performance is suppressed.

[0055] In addition, when the washing liquid is heated using the hot water heater 12, if the water level in the outer tub 3 is low, the rotation speed of the circulation pump 8a is reduced and an appropriate amount of washing liquid is sprayed onto the clothes from the lower outlet 10a (see FIG. 4), preventing the hot water heater 12 from being exposed and preventing dry heating. This allows the amount of water to be reduced during hot water washing, making it possible to wash with a highly concentrated detergent solution. According to the above configuration, a washing machine capable of performing washing with high washing performance according to the amount of laundry can be realized.

[0056] <<Other embodiments>> 1. In the above embodiment, a washer / dryer having a drying function has been described as an example, but it is of course applicable to a washing machine having only a washing function.

[0057] 2. The present invention is not limited to the configuration of the above-described embodiment, and various modifications and specific forms are possible within the scope of the appended claims. [Explanation of symbols]

[0058] 3 Outer tank 4 Rotating drum (inner tank) 4m motor 8a Circulation pump 9 Circulation flow path 10a Lower discharge port (discharge port) 10b Upper discharge port (discharge port) 12 Hot water heater 19 Control device A2 rotation speed (low rotation speed) A3 Rotational speed (very low rotational speed) S Washing dryer (washing machine)

Claims

1. an inner tub in which laundry is stored and which rotates; A motor that rotates the inner tank; An outer tub in which wash water is stored; A circulation flow path for circulating the washing water in the outer tub; A circulation pump that sends the washing water in the outer tub to the circulation flow path; and a control device for controlling the The circulation flow path has a plurality of outlets each having different heights for discharging the wash water onto the laundry, When the amount of laundry is small, the circulation pump is operated at a lower rotation speed than when the amount of laundry is large. A washing machine characterized by:

2. The washing machine according to claim 1, When the amount of laundry is small, the washing liquid is supplied from the lower outlet, When the amount of laundry is large, the washing liquid is supplied from the lower outlet and an upper outlet above the lower outlet. A washing machine characterized by:

3. an inner tub in which laundry is stored and which rotates; A motor that rotates the inner tank; An outer tub in which wash water is stored; A circulation flow path for circulating the washing water in the outer tub; A circulation pump that sends the washing water in the outer tub to the circulation flow path; and a control device for controlling the The circulation flow path has an upper outlet for supplying the washing water to the laundry from above, and a lower outlet for supplying the washing water to the laundry from below, When the amount of laundry is small, the washing liquid is supplied from the lower outlet. When the amount of laundry is large, the washing liquid is supplied from the lower outlet and the upper outlet. A washing machine characterized by:

4. The washing machine according to claim 1, When the amount of laundry is smaller than when the amount of laundry is small, the circulation pump is operated at a very low rotation speed that is lower than the low rotation speed when the amount of laundry is small. A washing machine characterized by:

5. The washing machine according to claim 4, The case where the amount of laundry is even smaller is a capacity of 2 kg or less. A washing machine characterized by:

6. an inner tub in which laundry is stored and which rotates; A motor that rotates the inner tank; An outer tub in which wash water is stored; A circulation flow path for circulating the washing water in the outer tub; A circulation pump that sends the washing water in the outer tub to the circulation flow path; a hot water heater for heating the washing liquid; and a control device for controlling the The circulation flow path has an upper outlet for supplying the washing water to the laundry from above, and a lower outlet for supplying the washing water to the laundry from below, When the laundry is heavy, heated laundry liquid is supplied from the upper outlet and the lower outlet, When the laundry load is small, heated laundry liquid is supplied from the lower outlet. A washing machine characterized by:

7. The washing machine according to claim 6, When the laundry load is large, the circulation pump is operated at a higher rotation speed than when the laundry load is small, and the heated laundry liquid is circulated through the circulation flow path. A washing machine characterized by:

Images