JP7630798B2 - Top-loading washing machine - Google Patents

Description

The present invention relates to a vertical washing machine.

The vertical washing machine described in Patent Document 1 below includes an outer tub that stores water, a washing tub that is placed inside the outer tub and stores laundry, and a motor that rotates the washing tub. In the vertical washing machine, a tub rotation process is performed in either the washing process or the rinsing process after the washing process. In the tub rotation process, the washing tub containing water rotates, and the water in the outer tub rises between the outer tub and the washing tub and is sprayed onto the laundry in the washing tub from an inlet and outlet at the top end of the washing tub. This spraying of water from above also washes the laundry on the inlet and outlet side.

JP 2020-5794 A

Although not disclosed in Patent Document 1, in a typical vertical washing machine, an overflow port is provided at the top of the outer tub, and an overflow channel is connected to the overflow port. Water that rises to the overflow port in the outer tub flows from the overflow port through the overflow channel and is discharged outside the machine. In the washing and rinsing processes, a water supply process is performed at the beginning to accumulate water in the outer tub to a relatively high water level, so if a tub rotation process is performed in the first half of the process immediately after the water supply process, some of the water that rises in response to the rotation of the washing tub is wasted and discharged from the overflow port without being used for watering. Therefore, when water conservation is important, the tub rotation process cannot be performed in the first half of the process after the water supply process in each of the washing and rinsing processes, and can only be performed in the second half of the process when the water level has dropped to a certain extent due to washing, rinsing, etc. In other words, the presence of the overflow port restricts the timing of the tub rotation process. During the tub rotation process, which is carried out in the latter stages, the amount of water sprayed into the washing tub from above, i.e., the amount of water sprayed, is small, so there is a limit to how much improvement can be made to washing performance.

The present invention was made against this background, and aims to provide a vertical washing machine that conserves water and improves washing performance when spraying water onto laundry from above.

The present invention relates to a washing tub having a drive unit that generates torque, an outer tub that is provided with a drain outlet, an overflow outlet that is positioned higher than the drain outlet, and an opening that is positioned higher than the overflow outlet and that stores water, an inner tub that is disposed within the outer tub and that is provided with a through hole for passing water between the outer tub and the inner tub, and an inlet/outlet that faces the opening from below, and through which laundry is inserted and removed via the opening and the inlet/outlet, and that rotates under the torque of the drive unit, a drainage channel that is connected to the drain outlet and that discharges water from within the washing tub, a drain valve that opens and closes the drainage channel, and a drain valve that is connected to the overflow outlet and that is provided within the washing tub. The vertical washing machine includes an overflow channel that guides water from the overflow outlet to the drain channel, a water stop valve that opens and closes the overflow channel, and a control unit that executes a tub rotation process in which the drain valve closes the drain channel and stores water in the washing tub, and the drive unit is operated to rotate the inner tub during at least one of the washing process and the rinsing process after the washing process, thereby causing the water in the washing tub to rise between the outer tub and the inner tub and to be sprayed from the inlet and outlet onto the laundry in the inner tub, and a control unit that closes the overflow channel using the water stop valve while the inner tub is rotating in the tub rotation process.

The present invention is also characterized in that the vertical washing machine includes a water supply unit that supplies water to the washing tub, and the control unit executes a water supply process in which the drainage channel is closed by the drain valve and the water supply unit stores water in the washing tub before the tub rotation process, and during the water supply process, the overflow channel is opened by the water stop valve.

The present invention is also characterized in that the control unit opens the overflow channel using the stop valve in response to the stop of the drive unit during the tank rotation process.

The present invention is also characterized in that the vertical washing machine includes an actuator that operates both the drain valve and the water stop valve under the control of the control unit.

According to the present invention, in a vertical washing machine, a tub rotation process is performed in at least one of the washing and rinsing processes. In the tub rotation process, when water is stored in the washing tub, the inner tub rotates under the torque of the drive unit, so that the water in the washing tub rises between the outer tub and the inner tub and is sprayed onto the laundry in the inner tub from the inlet and outlet of the inner tub. This spraying of water from above also washes the laundry on the inlet and outlet side. During the rotation of the inner tub in the tub rotation process, the overflow channel connected to the overflow outlet of the outer tub is closed by the water stop valve, so water can be saved by eliminating the waste of water in the washing tub being discharged from the outlet channel through the overflow channel. Furthermore, in this case, in each of the washing and rinsing processes, the tub rotation process can be performed not only in the latter stages when the water level in the washing tub drops depending on washing and rinsing, but also in the first stages when the water level in the washing tub is high. If the tub rotation process is performed in the first stages, the amount of water sprayed onto the laundry in the inner tub can be increased, improving washing performance.

In addition, according to the present invention, during the water supply process before the tub rotation process, the overflow channel is opened by the stop valve, so water that reaches the overflow outlet can be guided from the overflow channel to the drain and discharged. In other words, in a vertical washing machine, the overflow function can be enabled during the water supply process, when overflow is required, and disabled during the rotation of the inner tub during the tub rotation process, when overflow is not required.

In addition, according to the present invention, during the tub rotation process, the overflow channel can be opened to enable the overflow function in response to the stopping of the drive unit, i.e., the stopping of water spraying onto the laundry in the inner tub.

In addition, according to the present invention, the water stop valve and the drain valve that opens and closes the drainage channel can be operated by a common actuator.

1 is a schematic vertical cross-sectional view of a top-loading washing machine according to an embodiment of the present invention; FIG. 2 is a block diagram showing the electrical configuration of the vertical washing machine. 4 is a flowchart showing a washing operation performed in the vertical washing machine. 10 is a flowchart showing a tub rotation process in a washing operation. FIG. 2 is a schematic perspective view of an upper portion of a washing tub in a vertical washing machine. FIG. 11 is a block diagram showing an electrical configuration of a vertical washing machine according to a modified example.

The following describes an embodiment of the present invention in detail with reference to the drawings. FIG. 1 is a schematic vertical cross-sectional view of a vertical washing machine 1 according to one embodiment of the present invention. The up-down direction in FIG. 1 is referred to as the up-down direction Z of the vertical washing machine 1, and the upper side of the up-down direction Z is referred to as the upper side Z1 and the lower side is referred to as the lower side Z2. The vertical washing machine 1 includes a housing 2 forming its outer shell, an outer tub 3 arranged in the housing 2, an inner tub 4 arranged in the outer tub 3, a pulsator 5 arranged in the inner tub 4, a motor 6 as an example of a drive unit arranged on the lower side Z2 of the outer tub 3, and an electric clutch 7 that switches the destination of the torque generated by the motor 6. The outer tub 3 and the inner tub 4 together constitute a washing tub 8.

The housing 2 is made of metal, for example, and is formed in a box shape. An opening 2B that connects the inside and outside of the housing 2 is formed on the top surface 2A of the housing 2. A door 10 for opening and closing the opening 2B is provided on the top surface 2A. A display operation unit 11 composed of a liquid crystal operation panel or the like is provided around the opening 2B on the top surface 2A. By operating the display operation unit 11, a user of the vertical washing machine 1 can select operating conditions for the washing operation performed by the vertical washing machine 1 and can instruct the vertical washing machine 1 to start or stop a washing operation. Information for the user is displayed on the display operation unit 11.

The outer tank 3 is made of resin, for example, and is formed into a cylindrical shape with a bottom. The axis J of the outer tank 3 extends in the vertical direction Z through the center of the outer tank 3. In the following, the radial direction based on the axis J is referred to as the radial direction R, and the circumferential direction around the axis J is referred to as the circumferential direction L. Within the radial direction R, the direction approaching the axis J is referred to as the radial inner direction R1, and the direction away from the axis J is referred to as the radial outer direction R2.

The outer tank 3 has a generally cylindrical circumferential wall 3A arranged along the vertical direction Z, a bottom wall 3B that closes the hollow portion of the circumferential wall 3A from the lower side Z2, and a ring-shaped annular wall 3C that protrudes radially inward R1 along the upper edge of the circumferential wall 3A. An overflow port 3D that penetrates the circumferential wall 3A in the radial direction R is provided at the upper end of the circumferential wall 3A. An opening 3E that communicates with the hollow portion of the circumferential wall 3A from the upper side Z1 is provided on the inside of the annular wall 3C. The opening 3E faces and communicates with the opening 2B of the housing 2 from the lower side Z2.

The annular wall 3C is provided with a door 12 for opening and closing the opening 3E. The lower surface of the annular wall 3C is provided with a guide surface 3F that is inclined diagonally downward while bordering the opening 3E. The bottom wall 3B is formed in a disk shape extending approximately horizontally. An insertion hole 3G is provided at the circular center position of the bottom wall 3B, and a drainage outlet 3H is provided in the bottom wall 3B radially outward R2 from the insertion hole 3G. The insertion hole 3G and the drainage outlet 3H penetrate the bottom wall 3B in the vertical direction Z. In the outer tank 3, the overflow outlet 3D is positioned higher than the drainage outlet 3H, and the opening 3E is positioned higher than the overflow outlet 3D.

A water supply passage 13 connected to a tap for city water is connected to the annular wall 3C of the outer tub 3 from the upper side Z1. A water supply valve 14 is provided in the middle of the water supply passage 13. The water supply valve 14 is, for example, an electromagnetic valve. The water supply passage 13 and the water supply valve 14 form a water supply section 15 that supplies water to the washing tub 8. When the water supply valve 14 is opened, it opens the middle of the water supply passage 13, thereby opening the entire water supply passage 13. When the water supply valve 14 is closed, it blocks the water supply passage 13 in the middle by closing the middle of the water supply passage 13. In the initial state immediately after the power of the vertical washing machine 1 is turned on, the water supply valve 14 is in a closed state.

One end of the drainage channel 16 is connected to the drain outlet 3H in the bottom wall 3B of the outer tank 3. A drain valve 17 is provided midway along the drainage channel 16. When the drain valve 17 is opened, it opens a portion of the drainage channel 16, thereby opening the entire drainage channel 16. When the drain valve 17 is closed, it blocks the drainage channel 16 midway by closing a portion of the drainage channel 16. In the initial state, the drain valve 17 is in a closed state.

When the water supply valve 14 is opened with the drain valve 17 closed, water is supplied from the water supply passage 13 into the outer tub 3, and water is stored in the outer tub 3, i.e., the washing tub 8. When the water supply valve 14 is closed, the water supply stops. When the drain valve 17 is opened, the water in the washing tub 8 is discharged outside the machine, i.e., outside the housing 2, through the drain passage 16.

The inner tub 4 is made of metal, for example, and is formed into a cylindrical shape with a bottom that is one size smaller than the outer tub 3, and can accommodate laundry Q inside. The inner tub 4 is arranged coaxially within the outer tub 3. When housed within the outer tub 3, the inner tub 4 can rotate about the axis J. The inner tub 4 has a substantially cylindrical circumferential wall 4A arranged along the vertical direction Z, a bottom wall 4B that closes the hollow portion of the circumferential wall 4A from the lower side Z2, and a ring-shaped annular wall 4C that protrudes radially inward R1 along the upper edge of the circumferential wall 4A.

The inner circumferential surface of the circumferential wall 4A is the inner circumferential surface of the inner tub 4. The circumferential wall 4A is surrounded by the circumferential wall 3A of the outer tub 3. The bottom wall 4B is provided at the lower end of the inner tub 4. The annular wall 4C faces the annular wall 3C of the outer tub 3 from the lower side Z2. An inlet/outlet 4D is provided inside the annular wall 4C. The inlet/outlet 4D is located at the upper end of the inner tub 4 and exposes the hollow part of the circumferential wall 4A to the upper side Z1. The inlet/outlet 4D faces and communicates with the opening 3E of the outer tub 3 from the lower side Z2. The user puts laundry Q in and takes it out of the inner tub 4 from the upper side Z1 through the open opening 2B, opening 3E, and inlet/outlet 4D.

The circumferential wall 4A and bottom wall 4B of the inner tub 4 are provided with a number of through holes 4E, and the water in the outer tub 3 flows between the outer tub 3 and the inner tub 4 through the through holes 4E and is also stored in the inner tub 4. Therefore, the water level in the outer tub 3 and the water level in the inner tub 4 are the same. Note that the through holes 4E may not be provided in the circumferential wall 4A, but may be provided only in the bottom wall 4B.

The bottom wall 4B of the inner tank 4 is formed in a disk shape and extends approximately parallel to the bottom wall 3B of the outer tank 3 at a distance to the upper side Z1. An insertion hole 4F penetrating the bottom wall 4B is formed at the circular center position of the bottom wall 4B that coincides with the axis J. A tubular support shaft 18 is provided in the bottom wall 4B, surrounding the insertion hole 4F and extending to the lower side Z2 along the axis J. The support shaft 18 is inserted into the insertion hole 3G of the bottom wall 3B of the outer tank 3, and the lower end of the support shaft 18 is located below the bottom wall 3B Z2.

The pulsator 5 is formed in a disk shape with the axis J as its center, and is disposed on the bottom wall 4B inside the inner tub 4. The upper surface of the pulsator 5 facing the entrance/exit 4D of the inner tub 4 is provided with a plurality of raised, radially-arranged raised portions 5A. The pulsator 5 is provided with a rotating shaft 19 that extends from the center of the circle along the axis J to the lower side Z2. The rotating shaft 19 is inserted into the hollow portion of the support shaft 18, and the lower end of the rotating shaft 19 is located on the lower side Z2 of the bottom wall 3B of the outer tub 3.

The motor 6 is an electric motor such as an inverter motor. The motor 6 is disposed in the housing 2 on the lower side Z2 of the outer tub 3. The motor 6 has an output shaft 20 that rotates around an axis J, and outputs the generated torque from the output shaft 20.

The clutch 7 is interposed between the lower ends of the support shaft 18 and the rotating shaft 19 and the upper end of the output shaft 20 protruding from the motor 6 to the upper side Z1. A known transmission mechanism is used as the clutch 7. The clutch 7 selectively transmits the torque output from the output shaft 20 of the motor 6 to one or both of the support shaft 18 and the rotating shaft 19. When the torque from the motor 6 is transmitted to the support shaft 18, the inner tub 4 receives the torque of the motor 6 and rotates around the axis J. When the torque from the motor 6 is transmitted to the rotating shaft 19, the pulsator 5 receives the torque of the motor 6 and rotates around the axis J.

The vertical washing machine 1 further includes an overflow channel 21 having one end 21A connected to the overflow port 3D of the circumferential wall 3A and the other end 21B connected to a downstream portion of the drain channel 16 that is farther away from the drain port 3H than the drain valve 17. The other end 21B is located at a lower position than the one end 21A. When the water level in the washing tub 8 rises to the overflow port 3D, the water on the water surface side, i.e., the upper side Z1, in the washing tub 8 falls from the overflow port 3D through the overflow channel 21 and is guided to the drain channel 16, through which it is discharged outside the machine.

The vertical washing machine 1 also includes a stop valve 22 provided in the overflow channel 21. When the stop valve 22 is opened, it opens the overflow channel 21 in its entirety by opening the overflow channel 21 in its entirety. When the stop valve 22 is closed, it blocks the overflow channel 21 in its entirety by closing the overflow channel 21 in its entirety. In the initial state, the stop valve 22 is in an open state.

Figure 2 is a block diagram showing the electrical configuration of the vertical washing machine 1. The vertical washing machine 1 includes a microcomputer 25 as an example of a control unit. The microcomputer 25 includes, for example, a CPU 26, a memory 27 such as ROM or RAM, and a timer 28 for measuring time, and is built into the housing 2 (see Figure 1).

The motor 6, clutch 7, water supply valve 14, drain valve 17, and stop valve 22 are each electrically connected to the microcomputer 25 via, for example, a drive circuit 29, and the display operation unit 11 is also electrically connected to the microcomputer 25. The microcomputer 25 turns the motor 6 ON to operate it, and turns it OFF to stop it. The microcomputer 25 can also control the direction of rotation of the motor 6. Therefore, the motor 6 can rotate forward or backward. The microcomputer 25 controls the clutch 7 to switch the destination of the torque of the motor 6 to one or both of the inner tub 4 and the pulsator 5.

The microcomputer 25 controls the opening and closing of the water supply valve 14, the drain valve 17, and the stop valve 22. Specifically, the vertical washing machine 1 includes a torque motor 30 that operates the drain valve 17, and an actuator 31 that is provided separately from the torque motor 30 and operates the stop valve 22, and the torque motor 30 and the actuator 31 are connected to a drive circuit 29. Therefore, the microcomputer 25 controls the opening and closing of the drain valve 17 by controlling the operation of the torque motor 30, and controls the opening and closing of the stop valve 22 by controlling the operation of the actuator 31.

When the user operates the display operation unit 11 to select operating conditions, etc., the microcomputer 25 accepts the selection. The microcomputer 25 controls the display content of the display operation unit 11.

The vertical washing machine 1 further includes a buzzer 32, a rotation speed reading device 33, and a water level detection unit 34, all electrically connected to the microcomputer 25. The microcomputer 25 notifies the user of the start and end of a washing operation by making the buzzer 32 emit a predetermined sound.

The RPM reading device 33 is a device that reads the RPM of the motor 6, or more precisely, the RPM of the output shaft 20 of the motor 6, and is composed of, for example, a Hall IC. The RPM read by the RPM reading device 33 is input to the microcomputer 25 in real time. The microcomputer 25 controls the motor 6 so that it rotates at the desired RPM by controlling the duty ratio of the voltage applied to the motor 6 based on the input RPM. The RPMs of the inner tub 4 and the pulsator 5 may be the same as the RPM of the motor 6, or may be a value obtained by multiplying the RPM of the motor 6 by a predetermined constant such as the reduction ratio of the clutch 7.

The water level detection unit 34 is a water level sensor that detects the water level in the washing tub 8. One example of the water level detection unit 34 is a pressure-type water level sensor that detects the water level in the washing tub 8 based on the pressure in the outer tub 3.

The microcomputer 25 executes a washing operation by controlling the operation of the motor 6, the clutch 7, the water supply valve 14, the drain valve 17, and the water stop valve 22. The washing operation includes a washing process for washing the laundry Q, a rinsing process for rinsing the laundry Q after the washing process, and a spin-drying process for spin-drying the laundry Q by rotating the inner tub 4 after the rinsing process. The vertical washing machine 1 may also be a washer-dryer that also executes a drying process for drying the laundry Q after the spin-drying process. In this embodiment, the rinsing process is executed twice, the first rinsing process being referred to as the first rinsing process, and the second rinsing process being referred to as the second rinsing process. The rinsing process may be executed only once, instead of multiple times.

When the user places laundry Q in the inner tub 4 and issues a command to start the washing operation, the microcomputer 25 starts the washing operation. The user may place detergent in the inner tub 4 before or after placing the laundry Q. Referring to the flowchart in FIG. 3, the microcomputer 25 first detects the amount of laundry Q in the inner tub 4, that is, the load amount (step S1). As an example of load amount detection, the microcomputer 25 detects the load amount from the variation in the number of rotations of the motor 6 when the inner tub 4 is rotated steadily at a low speed. The microcomputer 25 determines the water level W (see FIG. 1) of the water to be supplied and stored in the inner tub 4 based on the load amount detected earlier. The relationship between the water level W and the load amount is determined in advance by experiments or the like and stored in the memory 27.

Then, as the water supply process at the beginning of the washing process, the microcomputer 25 closes the drain valve 17 to close the drain channel 16, and supplies water to the washing tub 8 by continuously opening the water supply valve 14 (step S2). This causes water to accumulate in the washing tub 8 and the water level to rise. When the water level in the washing tub 8 rises to the previously determined water level W, the microcomputer 25 closes the water supply valve 14 to stop the water supply. This ends the water supply process. During the water supply process, the microcomputer 25 opens the stop valve 22 to keep the overflow channel 21 open.

Next, when water is stored in the washing tub 8, the microcomputer 25 executes the stirring process (step S3). Specifically, the microcomputer 25 switches the clutch 7 as necessary so that the torque of the motor 6 is transmitted to the pulsator 5, and then drives the motor 6 to rotate the pulsator 5. The pulsator 5 may rotate continuously in the same direction, but in this embodiment, the motor 6 is driven intermittently to rotate the pulsator 5 in a forward and reverse direction alternately at intervals of 1 to 2 seconds. In the stirring process, the laundry Q in the inner tub 4 is stirred and washed by the inverted pulsator 5. The pulsator 5 may rotate even during the water supply process in step S2, which makes it easier for the detergent to dissolve in water. The detergent dissolved in water breaks down dirt on the laundry Q. When a predetermined stirring time has elapsed, the microcomputer 25 ends the stirring process.

After the stirring process, the microcomputer 25 executes the loosening process while water continues to accumulate in the inner tub 4 (step S4). In the loosening process, the microcomputer 25 reverses the pulsator 5 by intermittently driving the motor 6 under conditions different from those in the stirring process. In this embodiment, as an example, the pulsator 5 reverses at a higher rotation speed than in the stirring process so as to alternately rotate forward and backward at intervals of 0.5 seconds, which is shorter than in the stirring process. As a result, the laundry Q immersed in water in the inner tub 4 is loosened by the reversing pulsator 5. Therefore, the uneven distribution of the laundry Q is eliminated. The uneven distribution of the laundry Q in the inner tub 4 is called imbalance. When a predetermined loosening time has elapsed, the microcomputer 25 ends the loosening process. In the washing process, the water level W immediately after the water supply process gradually decreases according to the progress of each process in the washing process, such as the stirring process and the loosening process.

After the loosening process, the microcomputer 25 executes the tub rotation process (step S5). Specifically, referring to the flowchart in FIG. 4, the microcomputer 25 first switches the clutch 7 so that the torque of the motor 6 is transmitted to the inner tub 4 (step S51). Next, the microcomputer 25 closes the overflow channel 21 by closing the stop valve 22 (step S52).

Next, the microcomputer 25 checks whether the water level in the washing tub 8 has reached a predetermined tub rotation water level (step S53). The tub rotation water level is a water level at which the water in the outer tub 3 will not overflow from the opening 3E when the inner tub 4 rotates from now on, and is specifically higher than half the internal height of the inner tub 4. If the water level in the inner tub 4 is not at the tub rotation water level (NO in step S53), the water level in the inner tub 4 is higher than the tub rotation water level, so the microcomputer 25 opens the drain valve 17 to drain the washing tub 8 (step S54).

If the water level in the washing tub 8 has reached the tub rotation water level (YES in step S53), the microcomputer 25 closes the drain valve 17 to close the drain passage 16, and operates the motor 6 with the water stored in the washing tub 8 up to the tub rotation water level (step S55). This causes the inner tub 4 to rotate at high speed, for example at 200 rpm. Then, a vortex is generated in the outer tub 3, and the water surface, which was previously horizontal, curves in a U-shape so that the center on the axis J side is lower and the outer periphery on the radially outer side R2 is higher (see the two-dot chain line S in Figure 1). This causes the water in the washing tub 8 to rise between the circumferential wall 3A of the outer tub 3 and the circumferential wall 4A of the inner tub 4.

The rising water passes between the ribs 3I arranged in a line on the underside of the annular wall 3C of the outer tub 3, swirling in a spiral and falling, and is sprayed onto the laundry Q in the inner tub 4 through the entrance 4D of the inner tub 4 (see the thick two-dot chain lines in Figures 1 and 5). The guide surface 3F of the annular wall 3C of the outer tub 3 guides the water passing between the ribs 3I downward toward the entrance 4D (see Figure 1).

Even if the amount of laundry Q is so large that it is about to spill out of the water surface after the water supply process, the laundry Q on the entrance/exit 4D side can be washed reliably by spraying water from the upper side Z1 as the inner tub 4 rotates. In addition, washing by spraying water can reduce damage to the laundry Q. Note that the tub rotation process may be performed only in the case of large-volume washing, where the amount of laundry Q is equal to or greater than a predetermined amount.

The tub rotation process is started with the laundry Q having been preliminarily eliminated by the loosening process in step S4, so that the rotation speed of the inner tub 4 increases smoothly during the tub rotation process up to the rotation speed at which watering begins. This allows the tub rotation process to be carried out smoothly. In addition, because the preliminarily loosening process makes it less likely for abnormal vibrations to occur in the inner tub 4 during the tub rotation process, it is possible to avoid the need to stop the rotation of the inner tub 4 in response to abnormal vibrations and eliminate the unevenness of the laundry Q in the inner tub 4. This helps to shorten the washing time.

During the tub rotation process, the microcomputer 25 detects the degree of imbalance of the laundry Q in the inner tub 4, that is, the eccentric load, while water continues to accumulate in the inner tub 4 (step S56). Specifically, as the imbalance of the laundry Q increases, the variation in the rotation speed of the motor 6 increases. Therefore, the microcomputer 25 detects the imbalance of the laundry Q in the inner tub 4 by reading the variation in the rotation speed of the motor 6 with the rotation speed reading device 33. In this case, it is possible to reduce time compared to the case where the inner tub 4 is drained once and then the degree of imbalance of the laundry Q is detected. The degree of imbalance of the laundry Q may be detected by another known method. If the imbalance of the laundry Q is a predetermined amount or more, it may affect the smooth rotation of the inner tub 4.

If no bias of a predetermined magnitude or more is detected (NO in step S56), and a predetermined tub rotation time has elapsed since the motor 6 started to rotate in step S55 (YES in step S57), the microcomputer 25 stops the motor 6 (step S58). Then, in response to the motor 6 being stopped, the microcomputer 25 opens the stop valve 22 to open the overflow channel 21 (step S59). This ends the tub rotation process.

As described above, the microcomputer 25 closes the overflow channel 21 by closing the water stop valve 22 during steps S52 to S59 in the tub rotation process, that is, while the inner tub 4 is rotating. This allows water to be saved by eliminating the waste of water in the washing tub 8 being discharged from the drainage channel 16 through the overflow channel 21. Furthermore, in this case, the tub rotation process can be performed not only in the latter half of the washing process when the water level in the washing tub 8 drops due to washing in the agitation process (step S3), but also in the first half of the washing process when the water level in the washing tub 8 is high, for example, immediately after the water supply process (step S2). If the tub rotation process is performed in the first half of the washing process, the amount of water sprayed on the laundry Q in the inner tub 4 can be increased, thereby improving the washing performance, or more precisely, the washing performance. In addition, in order to further reduce the discharge of water from inside the washing tub 8 into the overflow channel 21 while the inner tub 4 is rotating, the water stop valve 22 may be placed near the overflow outlet 3D in the overflow channel 21, or even at the overflow outlet 3D (see FIG. 1).

Meanwhile, during the water supply process before the tub rotation process (step S2), the microcomputer 25 opens the stop valve 22 to open the overflow channel 21 as described above. As a result, when the water level in the washing tub 8 rises during the water supply process and reaches the overflow outlet 3D, the water that has reached the overflow outlet 3D can be guided from the overflow channel 21 to the drainage channel 16 and discharged. In other words, in the vertical washing machine 1, the overflow function can be enabled during the water supply process, when overflow is required, and disabled during the rotation of the inner tub 4 during the tub rotation process, when overflow is not required.

Then, in the tub rotation process, as described above, the microcomputer 25 opens the overflow channel 21 by opening the stop valve 22 in response to the stopping of the motor 6 (step S59). In this way, in the tub rotation process, the overflow channel 21 can be opened in response to the stopping of the motor 6, i.e., the stopping of the water spraying on the laundry Q, to enable the overflow function. As a variant, the overflow channel 21 may be always closed during the entire period of the tub rotation process.

When the microcomputer 25 detects a bias of a predetermined magnitude or more during the tank rotation process (YES in step S56), it checks whether the current bias detection is the first bias detection in the current tank rotation process (step S60). The number of bias detections in the current tank rotation process is temporarily stored in the memory 27.

If this is the first time that imbalance has been detected (YES in step S60), the microcomputer 25 stops the motor 6 to temporarily suspend the rotation of the inner tub 4 (step S61). The microcomputer 25 then switches the clutch 7 so that the torque of the motor 6 is transmitted to the pulsator 5, and loosens the laundry Q in the inner tub 4 by, for example, reversing the pulsator 5 under the same conditions as the loosening process in step S4 (step S62). At this time, water has already accumulated in the inner tub 4 and the laundry Q is immersed in water and in a state where it is easy to loosen, so there is no need to supply water to loosen the laundry Q.

In order to loosen the laundry Q, the microcomputer 25 may rotate the inner tub 4 instead of the pulsator 5, or may rotate both the inner tub 4 and the pulsator 5. In addition, the inner tub 4 and the pulsator 5 may rotate in the same direction only, or may be reversed as described above.

After loosening the laundry Q for a predetermined time, the microcomputer 25 switches the clutch 7 so that the torque of the motor 6 is transmitted to the inner tub 4, and then resumes the rotation of the inner tub 4 (step S55). In other words, if an imbalance is detected for the first time in the tub rotation process, the imbalance is eliminated by loosening, and the rotation of the inner tub 4 is resumed. This allows the tub rotation process to be continued without having to stop the tub rotation process once to eliminate the imbalance of the laundry Q and then restart the tub rotation process, thereby further shortening the washing time. On the other hand, if the detection of imbalance in the current tub rotation process is the second or more times (NO in step S60), the microcomputer 25 stops the motor 6 (step S58), opens the water stop valve 22 (step S59), and stops the tub rotation process. Note that the processes related to the imbalance detection (steps S56 and S60 to S62) may be omitted in the tub rotation process.

Referring to FIG. 3, when the tub rotation process is completed or stopped as described above, the microcomputer 25 executes an agitation process similar to step S3 (step S6). When the agitation process is completed, the washing process is completed.

Next, the microcomputer 25 rotates the inner tub 4 at high speed with the drain valve 17 open as the spin-drying process after the washing process, i.e., the intermediate spin-drying process (step S7). The laundry in the inner tub 4 is spin-dried by the centrifugal force generated by this high-speed rotation. Water that seeps out of the laundry due to spin-drying is discharged outside the machine through the drain 16. At the end of the intermediate spin-drying process, the microcomputer 25 switches the clutch 7 to stop the motor 6 so that the torque of the motor 6 is not transmitted to the inner tub 4, and the inner tub 4 rotates by inertia. At the end of the intermediate spin-drying process, the microcomputer 25 closes the drain valve 17.

Next, the microcomputer 25 executes shower rinsing as the first rinsing step (step S8). Specifically, the microcomputer 25 supplies shower water to the inner tub 4 by intermittently opening the water supply valve 14 with the drain valve 17 closed. In this state, the microcomputer 25 rotates the inner tub 4 at a low speed, for example, 30 rpm, so that the shower reaches every corner of the laundry Q. This allows the laundry Q in the inner tub 4 to be rinsed evenly. Thereafter, the microcomputer 25 executes the same intermediate spin-drying step as step S7 (step S9). Note that each intermediate spin-drying step may be considered as part of the processing in the immediately following rinsing step.

Next, the microcomputer 25 executes a second rinsing process. The content of the second rinsing process is the same as the washing process, except that no detergent is present. Specifically, the microcomputer 25 supplies water as in step S2 (step S10), then agitates and rinses the laundry Q as in step S3 (step S11), loosens the laundry Q as in step S4 (step S12), and executes a tub rotation process as in step S5 (step S13). Then, when the microcomputer 25 agitates and rinses the laundry Q as in step S11 (step S14), the second rinsing process ends.

The effects obtained by the tub rotation process in the washing step can also be obtained by the tub rotation process in the second rinsing step. Therefore, for example, even in the first half of the second rinsing step when the water level in the washing tub 8 is high, such as immediately after the water supply process (step S10), the tub rotation process (step S13) can be performed by closing the water stop valve 22, so that the tub rotation process can be performed in the first half of the step. This increases the amount of water sprayed on the laundry Q in the inner tub 4, thereby improving the washing performance, or more precisely, the rinsing performance.

Finally, the microcomputer 25 executes a final spin-drying process similar to the intermediate spin-drying process (step S15). However, the rotation conditions of the inner tub 4 may be different between the intermediate spin-drying process and the final spin-drying process, and in particular, the maximum rotation speed of the inner tub 4 in the final spin-drying process is higher than the maximum rotation speed of the inner tub 4 in the intermediate spin-drying process. The washing operation ends when the final spin-drying process is completed.

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

For example, in the embodiment described above, each of the stirring process, loosening process, and tub rotation process is performed in both the washing process and the second rinsing process, but they may be performed in only one of the washing process and the second rinsing process, or in the first rinsing process. The tub rotation process in the washing process (step S5) and the tub rotation process in the second rinsing process (step S13) may be the same or different as described above. Also, one or both of the stirring process and loosening process may be omitted in the washing operation.

Figure 6 is a block diagram showing the electrical configuration of a vertical washing machine 1 according to a modified example. In Figure 6, the same parts as those explained so far are given the same reference numerals, and explanations of those parts will be omitted. The torque motor 30 (see Figure 2) that operates the drain valve 17 and the actuator 31 (see Figure 2) that operates the stop valve 22 may be omitted, and the vertical washing machine 1 may include a single actuator 41 that operates both the drain valve 17 and the stop valve 22.

The actuator 41 is composed of a two-stage torque motor or the like, and operates both the drain valve 17 and the stop valve 22 under the control of the microcomputer 25. Specifically, the actuator 41 operates in two stages from the OFF state, so that it can open and close both the drain valve 17 and the stop valve 22 at the same time, or selectively open and close only one of the drain valve 17 and the stop valve 22. In this way, the drain valve 17 and the stop valve 22 can be operated by a common actuator 41.

As another variation, the vertical washing machine 1 may include a three-way valve 42 that serves as both the drain valve 17 and the stop valve 22 (see FIG. 1). In this case, the three-way valve 42 is, for example, a solenoid valve. The three-way valve 42 is disposed at a connection portion of the drain channel 16 to which the other end 21B of the overflow channel 21 is connected. The three-way valve 42 may allow drainage from the overflow channel 21 to the outside of the machine while drainage from the drain outlet 3H is stopped, allow drainage from the drain outlet 3H to the outside of the machine while drainage from the overflow channel 21 is stopped, or may stop or allow drainage from either the drain outlet 3H or the overflow channel 21 at the same time.

In the above-described embodiment, the axis J of the inner tub 4 in the vertical washing machine 1 is arranged to extend vertically along the vertical direction Z (see FIG. 1), but the vertical washing machine 1 also includes a configuration in which the axis J is arranged to be slightly inclined with respect to the vertical direction Z.

REFERENCE SIGNS LIST 1 Vertical washing machine 3 Outer tub 3D Overflow port 3E Opening 3H Drain port 4 Inner tub 4D Inlet/outlet 4E Through hole 6 Motor 8 Washing tub 15 Water supply section 16 Drainage channel 17 Drainage valve 21 Overflow channel 22 Stop valve 25 Microcomputer 41 Actuator Q Laundry Z2 Lower side

Claims (4)

A drive unit that generates torque;
a washing tub having an outer tub provided with a drain outlet, an overflow outlet located at a position higher than the drain outlet, and an opening located at a position higher than the overflow outlet, and for storing water; an inner tub provided with a through hole for passing water between the outer tub and the inner tub, and an inlet/outlet facing the opening from below, and disposed within the outer tub, laundry is put in and taken out through the opening and the inlet/outlet, and the inner tub rotates by receiving a torque from the drive unit;
A drainage channel connected to the drain outlet for discharging water from the washing tub;
A drain valve that opens and closes the drainage path;
An overflow channel connected to the overflow outlet and directing water in the washing tub from the overflow outlet to the drainage channel;
A stop valve for opening and closing the overflow channel;
A control unit that executes a tub rotation process in which the drainage channel is closed by the drain valve and water is stored in the washing tub, and the drive unit is operated to rotate the inner tub, thereby causing the water in the washing tub to rise between the outer tub and the inner tub and to be showered onto the laundry in the inner tub from the inlet and outlet, during at least one of a washing process and a rinsing process after the washing process, and a control unit that prevents water from flowing from the overflow channel to the drainage channel by closing the overflow channel by the water stop valve during the rotation of the inner tub in the tub rotation process. A water supply unit that supplies water into the washing tub,
2. The vertical washing machine according to claim 1, wherein the control unit executes a water supply process in which the drainage channel is closed by the drain valve and the water supply unit is used to store water in the washing tub before the tub rotation process, and during the water supply process, the overflow channel is opened by the water stop valve. The vertical washing machine according to claim 1 or 2, wherein the control unit opens the overflow channel by the water stop valve in response to the stop of the drive unit during the tub rotation process. The vertical washing machine according to any one of claims 1 to 3, further comprising an actuator that operates both the drain valve and the water stop valve under the control of the control unit.

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