washing machine

Abstract

To provide a washing machine with improved cleaning power. [Solution] The washing machine S of the present invention comprises an inner tub 4 in which laundry e is contained and rotates, a motor 4m that rotates the inner tub 4, an outer tub 3 in which washing water is stored, and a control device 19 that is responsible for control. The washing process controlled by the control device 19 has a first process and a second process. The first process is a high-concentration washing process that uses less water than the second process. The washing process allows selection between a first course and a second course which is longer than the first course. The second process time of the second course differs from the rate of increase of the second process time of the first course, which is determined by the load.

Description

Technical Field

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

Background Art

[0002] There is a washing machine that performs the washing process in two high-concentration washings and the main wash. The main wash is a process of washing using a predetermined amount of detergent according to the weight of the laundry. The high-concentration wash is a pre-wash process that is performed before the main wash with washing water having a higher detergent concentration than the predetermined amount of detergent. Conventionally, when the load is large, for example, the high-concentration wash is performed for about 260 seconds and the main wash is performed for about 110 seconds. On the other hand, when the load is small, for example, the high-concentration wash is performed for about 45 seconds and the main wash is performed for about 390 seconds.

[0003] Here, when washing with a washing machine, there are usually soiled items and soiled items with heavy stains such as curry and meat sauce whose stains are difficult to remove.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, soiled items with oil stains such as curry and meat sauce tend to have stains that are difficult to remove.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a washing machine that further improves the detergency.

Means for Solving the Problems

[0007] To solve the aforementioned problems, the washing machine of the present invention comprises an inner tub in which laundry is contained and rotated, a motor that rotates the inner tub, an outer tub in which washing water is stored, and a control device that is responsible for control, wherein the washing process controlled by the control device comprises a first process and a second process, the first process being a high-concentration washing process that uses less water than the second process, the washing process being selectable between a first course and a second course which is longer than the first course, and the rate of increase in the second process time of the second course being different from that of the second process time of the first course which is determined by the load amount. Furthermore, the washing machine of the present invention comprises an inner tub in which laundry is contained and rotated, a motor that rotates the inner tub, an outer tub in which washing water is stored, and a control device that is responsible for control, and the washing process controlled by the control device comprises a first process and a second process, the first process being a high-concentration washing process that washes with less water than the second process, and the washing process is selectable between a first course and a second course which is longer than the first course, and when the second course is selected as the washing process When the load is less than a predetermined value in the low-load region, the second process takes longer than the first process. When the load is more than a predetermined value in the high-load region, the first process takes longer than the second process. Of the four processes—the first process in the low-load region, the second process in the low-load region, the first process in the high-load region, and the second process in the high-load region—the first process in the high-load region takes the longest time. The second course is then executed. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a washing machine that has improved cleaning power. [Brief explanation of the drawing]

[0009] [Figure 1] This is a perspective view of a washing and drying machine according to an embodiment of the present invention, viewed from diagonally above and in front. [Figure 2]Figure 1 is a central cross-sectional view of the washer-dryer, seen from the left side. [Figure 3] This is an exploded perspective view showing the outer tank with the tank cover removed and a portion of the rotating drum and outer tank cut out. [Figure 4] This is a block diagram showing the configuration of the control unit for a washing machine and dryer. [Figure 5] This flowchart outlines the washing and drying processes. [Figure 6] This diagram compares the cleaning performance when the high-concentration washing time (pre-wash time) is extended, based on the standard washing cycle. [Figure 7] This figure shows a comparison of the cleaning performance between the standard course and the oil stain course. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the following embodiments, the present invention will be explained using a drum-type washer-dryer as an example, but the present invention is also applicable to top-loading washing machines and top-loading washer-dryers.

[0011] Figure 1 is a perspective view of a washing and drying machine S according to an embodiment of the present invention, viewed from diagonally above and in front. The washing and drying machine S according to an embodiment of the present invention is a drum-type washing and drying machine.

[0012] <Enclosure 1> The washing machine / dryer S has a skeletal structure formed by combining side plates 1s and reinforcing materials (not shown), mainly made of steel plates and resin molded products, on top of a base 1b. The outer casing 1 is formed by attaching a front cover 1z and a top cover 1j to the skeletal structure using screws, engagement, etc. The front cover 1z has a door 2 pivotally supported around a vertical axis for loading and unloading laundry e. The front upper part of the door 2 is equipped with a power switch, an operation switch b1 for selecting the washing course, and a display b2.

[0013] <Outer tank 3 and rotating drum 4> Figure 2 is a central cross-sectional view of the washing and drying machine S in FIG. 1 as viewed from the left side. Inside the housing 1, a substantially bottomed cylindrical outer tub 3 for storing washing water and rinsing water is provided. The outer tub 3 is supported from below by a plurality of suspensions (not shown) fixed on the base 1b. The suspension is composed of a combination of a compression coil spring and a damper that imparts viscous damping such as air or oil. An upper part of the outer tub 3 is attached with a tension coil spring (not shown) engaged with the above-described skeleton member. The outer tub 3 is prevented from falling forward and backward by the spring force of the tension coil spring.

[0014] Inside the outer tub 3, a substantially bottomed cylindrical rotating drum (inner tub) 4 is rotatably supported. The user opens the door 2 and puts laundry e into the rotating drum 4. The rotating drum 4 has a large number of small holes 4k (see FIG. 3) for centrifugal dehydration and ventilation formed on the side and back surfaces. In addition, a fluid balancer 5 for reducing vibration caused by the imbalance of the laundry e during dehydration is provided on the outer periphery of the opening 4i (see FIG. 2) of the rotating drum 4. When the rotating drum 4 rotates at high speed during the dehydration process, the fluid inside the fluid balancer 5 moves to the opposite side of the bias of the laundry e to balance and reduce the centrifugal force to suppress vibration.

[0015] Inside the rotating drum 4 shown in FIG. 2, a plurality of lifters 4a for scraping up and dropping the laundry e to perform beating washing of the laundry e are provided. The rotating drum 4 is directly connected to the rotor of a motor 4m for driving the drum 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.

[0016] A tank cover 3c is provided at the front part of the outer tub 3. A rubber bellows 3b made of an elastic material and flexible is attached to the opening 3c1 of the tank cover 3c. The bellows 3b maintains the watertightness between the outer tub 3 and the door 2 by deforming flexibly. Water leakage from the outer tub 3 during washing, rinsing, and dehydration is suppressed by the bellows 3b. Further, a water receiving part 3u (see FIG. 2) is provided at the bottom of the outer tub 3. The washing and drying machine S includes a drainage path 6 and an overflow path (not shown). The overflow path is a path for overflow drainage (overflow discharge) when the water stored in the outer tub 3 exceeds a predetermined water level.

[0017] In addition, the washing and drying machine S includes a drainage hose and a dew condensation water hose (not shown). The drainage hose drains the washing water and rinsing water stored in the outer tub 3. The dew condensation water hose drains the dew condensation water dehumidified by cooling and condensation by the heat pump unit Hu (see FIG. 2).

[0018] FIG. 3 is an exploded perspective view in which the tank cover 3c is removed from the outer tub 3 and a part of the rotary drum 4 and the outer tub 3 is cut away. Note that FIG. 3 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 rotary drum 4 are cut away.

[0019] Between a water channel filter (not shown) and the outer tub 3, a circulation water channel 8 for circulating the water in the outer tub 3 through a circulation flow path 9 (see FIG. 3) and a circulation pump 8a (see FIG. 4) are provided.

[0020] <Circulation flow path 9> The outer tub 3 shown in FIG. 3 is composed of a bottomed short cylindrical outer tub body 3h and a tank cover 3c provided at the front opening 3h1 of the outer tub body 3h. A circulation flow path 9 (see FIG. 3) through which the washing water pumped up by the circulation pump 8a (see FIG. 4) passes is formed in the tank cover 3c. A lower discharge port 10a is formed at the lower part of the circulation flow path 9. Further, an upper discharge port 10b is formed at the upper part of the circulation flow path 9. In the tank cover 3c, a discharge air path 3c2 through which the drying air flows and a blowout port 3c3 for blowing the drying air into the rotary drum 4 are formed.

[0021] A circulating water channel 8 is connected to the circulation channel 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 discharge port 10a or the upper discharge port 10b using the circulation pump 8a (see Figure 4). Specifically, the water supplied to the circulating water channel 8 is supplied to the laundry e in the rotating drum 4 from the lower discharge port 10a, or from both the lower discharge port 10a and the upper discharge port 10b.

[0022] A water level sensor 11 (see Figure 4) for measuring the water level in the outer tub 3 is provided near the outer tub 3. In addition, a hot water heater 12 (see Figure 4) for heating the washing water inside the outer tub 3 is provided above the water receiving section 3u (see Figure 2) of the outer tub 3.

[0023] <Control device 19> Figure 4 is a block diagram showing the configuration of the control device 19 of the washing machine / dryer S. The control device 19 is equipped with a 32-bit or similar microcomputer (hereinafter referred to as "microcontroller") 110. The microcontroller 110 is equipped with hardware such as a CPU (Central Processing Unit), a DSP (Digital Signal Processor), volatile RAM (Random Access Memory), non-volatile ROM (Read Only Memory), and electrically updatable EEPROM (Electrically Erasable Programmable Read-Only Memory). The ROM stores control programs executed by the CPU, microprograms executed by the DSP, and various fixed data. The EEPROM stores information after the washing machine S is put into use and is updated as needed.

[0024] The microcontroller 110 acquires various information signals from the user's operation switch b1 (see Figure 1) and from the washing and drying processes (such as the amplified sensor current signals from the water level sensor 11, drainage temperature sensor T1, temperature sensor T2, temperature sensor T3, ambient temperature sensor T4, and conductivity sensor 14) as digital signals via an AD converter.

[0025] Furthermore, the microcontroller 110 is connected via a drive circuit to the motor 4m, water supply solenoid valve 16, drain valve 6c, circulation pump 8a, blower fan 22, compressor 307, variable expansion valve 308, drain pump 312, variable exhaust means 306, hot water heater 12, etc. The microcontroller 110 digitally controls the opening / closing, rotation, and energization of these components. A current sensor, such as a resistance detection type, is incorporated into the drive circuit 4m1 of the motor 4m to acquire motor torque. Furthermore, the microcomputer 110 controls the display unit b2 (see Figure 1), a buzzer (not shown), etc., to inform the user of information regarding the washing machine S. The microcomputer 110 also includes an operation pattern database 111, a process control unit 112, a rotation speed calculation unit 113, a clothing weight calculation unit 114, a conductivity measurement unit 115, a detergent amount / wash time determination unit 116, a turbidity determination unit 117, and a threshold storage unit 118 as control programs stored in ROM or the like. The operation pattern database 111 stores various operation patterns performed by the washing machine S, each with a key that indicates the operation pattern.

[0026] The microcontroller 110 starts up when the power switch (not shown) is pressed and power is turned on, and a basic control program for washing and drying, written in C language, Java, etc., is executed.

[0027] <Overview of the control method> As described above, the circulation pump 8a (see Figure 4) is provided with two discharge ports: an upper discharge port 10b (see Figure 3) and a lower discharge port 10a (see Figure 3). With this configuration, depending on the amount of laundry e (see Figure 2), the washing process is carried out by either using both the lower outlet 10a and the upper outlet 10b as shower outlets for the laundry e (see Figure 2), or using only the lower outlet 10a as the 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 is low, or when using hot water washing, the rotation speed of the circulation pump 8a is reduced so that the washing liquid is discharged only from the lower outlet 10a (see Figure 3) to the laundry e (see Figure 2). On the other hand, if the amount of laundry e to be discharged is large and the water level is high, the rotation speed of the circulation pump 8a is increased to discharge the laundry liquid onto the laundry e from the lower discharge port 10a (see Figure 3) and the upper discharge port 10b (see Figure 3).

[0029] Based on the sensing value of the amount of clothing (laundry e), the rotation speed of the circulation pump 8a during the washing process (during the first and second processes) is determined. The sensing of the amount of clothing (laundry e) is performed at the start of operation by rotating the rotating drum 4 with the clothing inside using the motor 4m, and estimating the amount of clothing (laundry e) from the current value detected by the current sensor. Since the current value and torque value of the motor 4m are proportional, the amount of clothing (laundry e) that determines the magnitude of the torque can be determined by obtaining the current value.

[0030] If the amount of laundry exceeds a predetermined threshold, the circulation pump 8a is set to a rotational speed (for example, 2100 rpm) at which laundry liquid is discharged from both the upper outlet 10b and the lower outlet 10a shown in Figure 3, in order to promote the impregnation of the laundry liquid into the clothes. When the amount of laundry is less than a predetermined threshold, the rotation speed of the circulation pump 8a is set to a lower speed than when the amount of laundry is greater, and the washing liquid is discharged only from the lower discharge port 10a (see Figure 3) (for example, 1900 rpm). The predetermined threshold for the amount of laundry regarding the rotation speed of the circulation pump 8a varies depending on the specifications of the washing machine, etc., and is set appropriately based on prior experiments and simulations, as well as the purpose. The same applies to the rotation speed.

[0031] Furthermore, if there is only a small amount of clothing, the detergent concentration will be higher, increasing the risk of foaming, so the detergent solution should be circulated at an even lower rotation speed (for example, 1700 rpm). In the hot water washing process, if 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 there is a large amount of laundry to reduce the risk of the hot water heater running dry. This suppresses the washing liquid from being stirred up by the lifter 4a.

[0032] <Overview of the washing and drying processes> Next, we will explain the overview of the control of the washing and drying processes of the washer-dryer S. Figure 5 is a flowchart showing an overview of the washing and drying processes. The washing and drying machine S is controlled using the control device 19 (see Figure 4). When washing, the user opens door 2 (see Figure 2), places the laundry e into the rotating drum 4, and closes door 2. Then, the user selects the washing cycle course by operating the control switch b1 (see Figure 1).

[0033] As a result, the control device 19 receives input for the selection of a course for the operation process of the washing and drying machine S (course selection). Here, the control device 19 reads the corresponding operation pattern from the operation pattern database 111 (see Figure 4) based on the input course for the operation process. Please note that the following explanation assumes that the standard wash and dry cycle (wash, rinse twice, spin, dry) has been selected.

[0034] In step S1 of Figure 5, the control device 19 performs a process to detect the weight (amount of clothing) of the laundry e (see Figure 2) placed in the rotating drum 4 (clothing amount sensing). Specifically, the process control unit 112 (see Figure 6) drives the motor 4m to rotate the rotating drum 4, and the clothing weight calculation unit 114 (see Figure 4) calculates the weight (amount of clothing) of the laundry e before water is added from the current of the motor 4m.

[0035] In step S2, the control device 19 performs a process to calculate the amount of detergent and the operating time, the water supply solenoid valve 16 (see Figure 2) is opened, and water is supplied according to the amount of laundry (water supply process). Subsequently, the conductivity measuring unit 115 detects the conductivity (hardness) of the supplied water using the conductivity sensor 14. The conductivity sensor 14 measures conductivity (electrical conductivity of water) by passing an electric current between electrodes immersed in the supplied water. Furthermore, a drainage temperature sensor T1 located at the bottom of the outer tub 3 (for example, at the drain outlet 3o (see Figure 2)) detects the temperature of the supplied water. The detergent amount / wash time determination unit 116 determines the amount of detergent to be added and the operating time by map search based on the detected amount of laundry, the conductivity (hardness) of the water obtained using the value detected from the conductivity sensor 14 in the conductivity measurement unit 115, and the water temperature. The process control unit 112 then displays the determined detergent amount and operating time on the display unit b2 (see Figure 1).

[0036] The control device 19 waits for a predetermined time (detergent dispensing waiting process). The user, referring to the amount of detergent displayed on the display unit b2 during the waiting period, dispenses the detergent into the detergent dispenser (not shown). If automatic detergent dispensing is set, the detergent dispensing operation is omitted. The washing process is broadly divided into a pre-washing process (high-concentration washing process) (step S3) and a main washing process (step S5). The main washing process is performed after the water supply process in step S4. In the washing process, the pre-washing process is the "first process," and the main washing process is the "second process." The control device 19 performs the detergent dissolving process before the pre-washing process (step S3). The water supply solenoid valve 16 is opened and water is supplied. The water is guided to the detergent inlet and then poured into the outer tank 3. The detergent solution poured into the outer tank 3 is supplied to the water receiving section 3u (see Figure 2) located at the bottom of the rotating drum 4 via a water supply path (not shown). After the detergent solution is poured in, the circulation pump 8a (see Figure 4) is driven in the reverse direction to agitate the supplied detergent solution.

[0037] In the detergent dissolving process, when the circulation pump 8a is driven in the forward direction, water from the water receiving section 3u enters the suction port (not shown) of the circulation pump 8a via the drain port 3o (see Figure 2) and the lint filter's water channel filter. The pressurized wash water from the circulation pump 8a returns to the water receiving section 3u (see Figure 2) via the circulation water channel 8 (see Figure 3) which communicates with the outlet of the circulation pump 8a, the lower discharge port 10a of the circulation flow path 9, and the upper discharge port 10b.

[0038] At this point, the control device 19 detects conductivity using the conductivity sensor 14 located in the water receiving section 3u and compares it with the conductivity database for high-concentration detergent solution and the conductivity database for fabric softener solution. By repeatedly circulating the laundry solution using the circulation channel 9, a uniform high-concentration detergent solution is generated by dissolving the detergent in a small amount of water. Then, the rotating drum 4 is rotated to agitate the laundry e, and the detergent solution pumped up through the circulation channel 9 (see Figure 3) by the circulation pump 8a is evenly sprayed onto the laundry e from the lower discharge port 10a (see Figure 3) and the upper discharge port 10b or lower discharge port 10a of the spray nozzle.

[0039] In step S3, the control device 19 performs a pre-washing process (high-concentration washing: first process). The operation control unit 151 washes the clothes with a water volume lower than that used in the subsequent main washing process, i.e., with a high-concentration detergent solution (high-concentration washing). Hereinafter, the operation in which the rotating drum 4 is rotated while the high-concentration detergent solution is permeated into the clothes at a lower water level than that used in the main washing process will be referred to as high-concentration washing. In this embodiment, the high-concentration washing process is operated at a constant water level without supplying water during the process, but it may also be operated while supplying water.

[0040] Furthermore, in this embodiment, when using liquid detergent or concentrated liquid detergent, the rotating drum 4 is rotated at a higher rotation speed compared to the case of powder detergent to perform high-concentration washing, while when using powder detergent, the rotating drum 4 is rotated at a lower rotation speed. This makes it possible to suppress foaming when using powder detergent during high-concentration washing, which tends to foam easily, while allowing the liquid detergent to penetrate the laundry e more effectively and increasing the cleaning power when using liquid detergent. In the pre-washing process (step S3), normally, the outer tub 3 contains laundry e soaked in detergent solution, and a small amount of detergent solution is present in the water receiving section 3u at the bottom of the outer tub 3. By rotating the rotating drum 4, the laundry e is lifted to the top of the rotating drum 4, and then dropped to the bottom by gravity in a tumbling action. This squeezes out the detergent solution soaked into the laundry e, so the circulation pump 8a is driven intermittently as needed to spray detergent solution onto the laundry e again.

[0041] In step S4, the control device 19 opens the water supply solenoid valve 16 (see Figure 2) and supplies water to the outer tub 3 up to a predetermined set water level according to the washing course and amount of laundry.

[0042] In step S5, the main washing process (second process) is performed. In the main washing process, the control device 19 rotates the rotating drum 4, and the laundry e is lifted by the lifter 4a (see Figure 2) and then dropped in a beating washing action. At predetermined intervals, the conductivity of the washing liquid is measured by the conductivity sensor 14. The degree of soiling at this point, based on the measured conductivity, is defined as the first degree of soiling (d1). The beating washing and the measurement of the conductivity of the washing liquid using the conductivity sensor 14 (the nth degree of soiling (dn) (n: natural number)) are repeated multiple times. dn, which represents the nth degree of soiling, is stored in the EROM by the control device 19 and used as feedback information for the process time of the main washing process.

[0043] Next, a rinsing process (step S6) and a dewatering process (step S7) are performed. In step S8 of Figure 5, it is determined whether or not it is a wash-and-dry cycle. If you do not want to perform a wash and dry cycle (No in step S8), the process will end. If you choose to perform a wash and dry cycle (Yes in step S8), the drying process will be performed in step S9, and the cycle will be completed.

[0044] <Comparison of oil stain removal effectiveness> By the way, oily stains, such as curry and meat sauce, are difficult to remove even after the washing process. Therefore, we extended the time of the pre-washing process (high-concentration washing) in step S3 of Figure 5 and compared the changes in stain removal.

[0045] Figure 6 shows the relationship between high-concentration cleaning time and cleaning efficiency at a load of 30%. The horizontal axis shows the high-concentration cleaning operation time (seconds), and the vertical axis shows the cleaning efficiency (percentage). The cleaning efficiency was calculated using the following equation (1).

number

[0046] Figure 6 shows a comparison of cleaning performance when the high-concentration wash time (pre-wash time) is extended, using the standard wash cycle as a baseline. The high-concentration wash time for the standard wash cycle corresponds to 45 seconds, and tests were conducted by extending the time to 135 seconds and 225 seconds. The load test was conducted using a JIS standard test cloth with a rated capacity of 10 kg, applying curry stains, meat sauce stains, and blood stains to 3 cm square pieces of blended cloth (35% cotton, 65% linen) with a load of 30% of the washing capacity (rated capacity) in a drum-type washing machine.

[0047] As shown in Figure 6, the removal of curry stains (solid line), meat sauce stains (dashed line), and blood stains (dotted line) is maximized when the high-concentration washing time is extended by approximately 180 seconds. In other words, the stains are removed most effectively when the high-concentration washing time is extended by approximately 180 seconds. Furthermore, even when the high-concentration washing time was extended by approximately 180 seconds or more, the cleaning efficiency reached a saturation point and did not decrease. For example, curry stains (solid line) showed maximum cleaning efficiency when the high-concentration washing time was extended by approximately 180 seconds, after which a decrease in cleaning efficiency was observed.

[0048] When the high-concentration washing time was extended by more than 180 seconds, the actual soiling of the JIS standard test cloth was observed to be discolored yellow throughout. This is presumed to be due to the re-adhesion of curry, meat sauce, and blood stains. Therefore, even if high-concentration washing (pre-washing) is performed for a long time, the dirt re-adheses to the JIS standard test cloth, making it even dirtier. For this reason, it is assumed that there is an optimal time for high-concentration washing (pre-washing). As described later, the optimal time is set according to the amount of clothing (load).

[0049] <Consideration of control that maximizes oil stain removal according to load> In a drum-type washing machine with a rated capacity of 10 kg, a 3 cm square piece of blended fabric (35% cotton, 65% linen) stained with curry was added to a JIS standard test cloth weighing 0.5 kgw to 13 kgw. Then, using commercially available liquid detergent, the stain removal was tested by extending the pre-wash (high-concentration wash) and main wash times as shown in Figure 5.

[0050] The pre-wash (high-concentration washing) in step S3 of Figure 5 was performed under the following conditions: water supply: approximately 10L, detergent concentration: 2.3 times the standard detergent concentration. Subsequently, in step S4 (water supply) in Figure 5, the water supply solenoid valve 16 was opened to add approximately 10L of water, diluting the detergent concentration from 2.3 to 1.0. Subsequently, in step S5 (main wash) in Figure 5, the water supply from the water supply solenoid valve 16 is approximately 0L, and the detergent concentration is 1.0 times the default value during the washing process.

[0051] Depending on the load, there are standard courses ranging from control logic 1 for washing course 1 to control logic 4 for washing course 4. A load of 0-1.5kg corresponds to the standard course of Washing Course 1 (Control Logic 1). A load of 2.0 to 4.5 kg corresponds to the standard course of Washing Course 2 (Control Logic 2). A load of 5.0 to 10.5 kg corresponds to the standard course of Washing Course 3 (Control Logic 3).

[0052] A load of 11.0-13.0 kg corresponds to the standard course of Washing Course 4 (Control Logic 4). The following findings were obtained from the above test. Table 1 shows the dirt removal trend based on the test results and a list of control settings that maximize dirt removal for each load. [Table 1]

[0053] Table 1 shows that the less the load, the better the cleaning results when the high-concentration washing time is extended. Beyond a predetermined load (amount of clothing), there is a tendency for the washing time to be extended as the load increases. This is thought to be because the detergent is distributed more evenly to the load when the load is small, while when the load is large, the amount of water is insufficient relative to the load, and the detergent is not distributed as well. In other words, this indicates that the results vary depending on the amount of water used during the high-concentration washing process relative to the load, and the bath ratio, which is the ratio of laundry e to water volume. Optimizing the amount of water and bath ratio for stain removal requires a lot of research time, so this time, we maintained the current specifications and adjusted only the operating time to obtain maximum cleaning power.

[0054] <Dirt removal tendency based on load> Table 1 shows that the tendency for dirt removal based on load is as follows. In the first stain removal trend for loads of 0-8.0 kg, extending the high-concentration washing time (pre-wash time) improves stain removal. However, stain removal saturates even when the high-concentration washing time is extended by more than 3 minutes. Furthermore, extending the main wash time does not change stain removal. In the second stain removal trend for loads of 9.0-13.0 kg, extending the high-concentration washing time (pre-wash time) does not significantly improve stain removal. This is because the low water volume and high fabric volume during the high-concentration washing (pre-wash) lead to poor fabric movement. As a solution, it is recommended to reduce the extension of the high-concentration washing time (pre-wash time) and instead extend the main wash time with increased water volume (increased water volume relative to fabric volume).

[0055] Based on these results, for loads of 0-4.5 kg, the high-concentration wash (pre-wash) will be extended by 3 minutes, while the main wash will not be extended. For loads of 11.0-13.0 kg, extend the high-concentration wash (pre-wash) by 1 minute. Extend the main wash by 9 minutes. A load of 5.0 to 10.5 kg represents the boundary between the first dirt removal tendency (load of 0 to 8.0 kg) and the second dirt removal tendency (load of 9.0 to 13.0 kg).

[0056] Therefore, for loads of 5.0 to 10.5 kg, we decided to extend the high-concentration wash (pre-wash) by 3 minutes and the main wash by 3 minutes. <Run times for standard and high-concentration washing (pre-wash) and main wash cycles for heavy oil stains relative to the load of laundry> Based on the above findings (see Table 1), the operating times for high-concentration washing (pre-wash) and main wash for standard and heavily soiled loads and oily stains were set as shown in Table 2. [Table 2]

[0057] In Table 2, the standard course corresponds to laundry with normal soiling (i.e., the first course). The oily soiling course corresponds to laundry with oily soiling (i.e., the second course). Note that the standard course and the oily soiling course are selectable. Table 2 shows that for the standard course (first course), the load of 0-4.5 kg corresponds to 45 seconds for high-concentration washing (pre-wash) (first step) and 390 seconds for the main wash (second step). For the standard course with a load of 5-10.5 kg, the high-concentration wash (pre-wash) (first step) takes 260 seconds, and the main wash (second step) takes 110 seconds.

[0058] For the oil stain course (second course), with a load of 0-4.5 kg, the high-concentration wash (pre-wash) (first step) takes 225 seconds (3 minutes longer than the standard course), and the main wash (second step) takes 390 seconds. For the oil stain course (second course), with a load of 5-10.5 kg, the high-concentration wash (pre-wash) (first step) takes 440 seconds (3 minutes longer than the standard course), and the main wash (second step) takes 290 seconds (3 minutes longer than the standard course).

[0059] In summary, the time for the second step (main wash) of the second course (oil stain course) increases at a different rate than the time for the second step (main wash) of the first course (standard course) which is adjusted according to the load. In other words, the time for the second step (main wash) of the second course (oil stain course) increases at a higher rate than the time for the second step (main wash) of the first course (standard course) which is adjusted according to the load. As a result, oil stain This can improve the cleaning efficiency.

[0060] From another perspective, when the oil stain course (second course) is selected as the washing process, if the load is less than a predetermined value (low load region), the oil stain course (second course) is executed in such a way that the main washing process (second course) takes longer than the pre-wash process (first process). In other words, as shown in Table 2, when the load is less than a predetermined value (0 to 4.5 kg) in the oil stain course (second course), the pre-wash process (first process) is 225 seconds and the main washing process (second process) is 390 seconds, so in the low load region, the main washing process (second process) takes longer than the pre-wash process (first process). On the other hand, when the oil stain course (second course) is selected as the washing process, if the load is greater than a predetermined value (high load region), the oil stain course (second course) is executed in such a way that the pre-wash process (first process) takes longer than the main washing process (second process). In other words, as shown in Table 2, in the high load region where the load is greater than a predetermined value (5 to 10.5 kg) in the oil stain course (second course), the pre-wash process (first process) takes 440 seconds and the main washing process (second process) takes 290 seconds. Therefore, in the high load region, the pre-wash process (first process) takes longer than the main washing process (second process). Furthermore, when the oil stain course (second course) is selected as the washing process, as shown in Table 2, the oil stain course (second course) is executed with the following settings: the first step in the low-load area (225 sec), the second step in the low-load area (330 sec), the first step in the high-load area (440 sec), and the second step in the high-load area (290 sec). Of the four steps, the first step in the high-load area (440 sec) is set to be the longest, and the oil stain course (second course) is executed. Incidentally, when the normal course (first course) is selected for the washing process, as shown in Table 2, the second course (390 sec), which is in the low-load area, is set to take the longest time among the four courses, and the normal course (first course) is executed. Thus, the longest timed step differs between the normal course (first course) and the oil-stained course (second course). Furthermore, when comparing the normal course (first course) and the oil-stained course (second course), the first step in the low-load region of the normal course is 45 seconds, while the first step in the oil-stained course is 225 seconds. In other words, the time for the first step in the oil-stained course is set to be five times longer than the first step in the normal course. In other words, whether the oil stain course (second course) or the normal course (first course) is selected, the timing of the pre-washing process (first process) and the main washing process (second process) was optimized depending on whether the load exceeded a predetermined value or not. The predetermined load value, as shown in the example in Table 2, lies between 4.5 kg and 5 kg. This predetermined value can be set appropriately according to the washing machine specifications and within the range that provides the desired effect.

[0061] Figure 7 shows a comparison of the cleaning performance between the standard course and the oil stain course. The test conditions involved using commercially available liquid detergent. As test material, 3.0 kg of JIS standard test cloth was used (low load area), and 0.1 g each of curry and meat sauce were applied to a 3 cm square blended cloth (35% cotton, 65% linen).

[0062] As shown in Figure 7, when washing with the standard cycle, the cleaning efficiency of curry stains was 37.4%, while when washing with the oil stain cycle, the cleaning efficiency was 40.8%, indicating that the oil stain cycle provided a better cleaning result. When washing meat sauce using the standard cycle, the cleaning efficiency was 27.8%, while when washing it using the oily cycle, the cleaning efficiency was 36.3%, indicating that the oily cycle provided a better cleaning result. From the above, it was confirmed that the oil stain course (course 2) provides a higher level of cleaning compared to the standard course (course 1). Furthermore, it was confirmed that the oil-stain course (course 2) provided a higher level of cleaning compared to the standard course (course 1) even in high-load areas.

[0063] <Effects and Effects> With the above configuration, in order to improve cleaning power, each process was optimized appropriately according to the amount of laundry (amount of laundry e; load). Specifically, the high-concentration washing time and the main washing time were optimized according to the volume of laundry and the degree of soiling (normal soiling and oily soiling). As shown in Table 2, by optimizing the high-concentration washing time (pre-wash time) and the main washing time after the water supply process for each load, we were able to remove stubborn food-derived oil stains such as curry and meat sauce better than with the standard washing course (improving stain removal).

[0064] Specifically, when using the oil stain course (second course), more precisely, the time for the second step (main wash) of the second course (oil stain course) is longer than the time for the second step (main wash) of the first course (standard course) in the high-load range. The first step (pre-wash) of the second course (oil stain course) is 3 minutes longer than the first step (pre-wash) of the first course (standard course). The second step (main wash) of the second course (oil stain course) is 3 minutes longer than the second step (main wash) of the first course (standard course) when the load is high, resulting in improved cleaning power. It also has high cleaning power against animal oils. When comparing the second course (oil stain course), as shown in Table 2, in the low-load region where the load is less than a predetermined value, the main wash process (second course) is set to take longer than the pre-wash process (first course), and the second course is executed. On the other hand, in the high-load region where the load is greater than a predetermined value, as shown in Table 2, the high-concentration pre-wash process (first course) is set to take longer than the main wash process (second course), and the second course is executed. Furthermore, the first course in the high-load region is set to take the longest, and the second course is executed. This makes it possible to wash oil-stained laundry e appropriately according to the amount of laundry e, thereby improving the stain removal effect.

[0065] In this way, we were able to optimize the time for high-concentration washing (pre-wash) and the main wash according to the laundry capacity (load) and the degree of soiling. Based on the above, it is possible to realize a washing machine S (washer dryer) with improved cleaning power.

[0066] <<Other Embodiments>> 1. The present invention is not limited to the configuration of the embodiments described above, and various modifications and specific forms are possible within the scope of the appended claims. [Explanation of Symbols]

[0067] 3 Outer tank 4 Rotating drums (inner tub) 4m motor 8a Circulation pump 9 Circulation channels 10a Lower discharge port (discharge port) 10b Upper discharge port (discharge port) 12. Hot water heater 19 Control device S Washing dryer (washing machine)

Claims

1. A rotating inner tub containing laundry, A motor that rotates the inner tank, An outer tub where the washing water is stored, Equipped with a control device responsible for control, The washing process controlled by the control device comprises a first step and a second step. The first step is a high-concentration washing step that uses less water than the second step. The washing process allows selection between a first course and a second course that is longer than the first course. The time for the second process of the second course differs from the time for the second process of the first course, depending on the load, in terms of the rate of increase in time. A washing machine characterized by the following features.

2. A rotating inner tub containing laundry, A motor that rotates the inner tank, An outer tub where the washing water is stored, Equipped with a control device responsible for control, The washing process controlled by the control device comprises a first step and a second step. The first step is a high-concentration washing step that uses less water than the second step. The washing process allows selection between a first course and a second course that is longer than the first course. When the second course is selected as the washing step, In the low-load region where the load is less than a predetermined value, the second step will take longer than the first step. In the high-load region where the load amount is greater than a predetermined value, the first step will take longer than the second step. Furthermore, the second course is executed such that, among the four steps—the first step in the low-load region, the second step in the low-load region, the first step in the high-load region, and the second step in the high-load region—the first step in the high-load region is set to take the longest time. A washing machine characterized by the following features.

3. In the washing machine according to claim 1, The time for the second process of the second course increases at a higher rate than the time for the second process of the first course, depending on the load. A washing machine characterized by the following features.

4. In the washing machine according to claim 1, The time for the second step of the second course is In the low-load region, the time is approximately the same as the time of the second process of the first course. In the high-load region, the time is longer than the time of the second process of the first course. A washing machine characterized by the following features.

5. In the washing machine according to claim 1, The first step in the second course is 3 minutes longer than the first step in the first course. A washing machine characterized by the following features.

6. In the washing machine according to claim 1, The second step in the second course is 3 minutes longer than the second step in the first course when the load is high. A washing machine characterized by the following features.

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