Top-loading washing machine

Abstract

To provide a vertical type washing machine which secures basic performance for washing, and which can perform efficient washing.SOLUTION: In a vertical type washing machine 1, tub rotation processing is performed in which by rotating a washing tub 4 in a state where water is stored in an outer tub 3, the water stored in the outer tub 3 is raised between the outer tub 3 and the washing tub 4, in a washing step, a control part performs tub rotation processing by allowing a water supply part to supply water to a predetermined low water level which is lower than a washing set water level W predetermined for the washing tub, and by rotating the washing tub 4 at predetermined rotational frequency by a drive part, so that water does not overflow from an overflow port 30 at the time of rotation of the washing tub 4.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a vertical washing machine. [Background Art]

[0002] The vertical washing machine described in Patent Document 1 below performs a tub rotation process in the washing step, in which the washing tub filled with washing water is rotated to raise the washing water in the outer tub between the outer tub and the washing tub, and pour the washing water onto the laundry in the washing tub. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2020-5794 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In the vertical washing machine described in Patent Document 1, when the washing water in the outer tub rises between the washing tub and the outer tub due to the tub rotation process, there is a problem that the washing water overflows from a water overflow port provided at an upper part of the outer tub and is drained. Therefore, in a vertical washing machine in which a washing step and a rinsing step are sequentially performed, there is a problem that the tub rotation process, which may cause overflow of washing water in which detergent is dissolved in the first half of washing, that is, in the washing step, should not be performed in consideration of improving the efficiency of the entire washing.

[0005] The present disclosure has been made to solve such a problem, and an object of the present disclosure is to provide a vertical washing machine that ensures basic washing performance and enables efficient washing. [Means for Solving the Problem]

[0006] (1) The vertical washing machine according to the Disclosure includes an outer tub for storing water, a washing tub rotatably disposed within the outer tub for storing laundry, a rotating blade provided at the bottom of the washing tub for agitating the laundry stored in the washing tub, a water supply unit for supplying water into the washing tub, an overflow port provided at the top of the outer tub for causing water to overflow when the outer tub is filled with water above a predetermined full water level, a drive unit that generates a driving force for rotating the washing tub and the rotating blade, and a control unit that controls the water supply unit and the drive unit, wherein the washing tub is rotated with water accumulated in the outer tub to raise the water accumulated in the outer tub between the outer tub and the washing tub, the control unit, in the washing process, supplies water to the washing tub using the water supply unit to a predetermined low water level less than a predetermined wash setting water level, and rotates the washing tub at a predetermined number of rotations using the drive unit to perform the tub rotation process so that water does not overflow from the overflow port when the washing tub is rotated.

[0007] According to this disclosure, in the first half of the washing process, the control unit supplies water to the washing tub to a predetermined low water level (referred to as the "suitable water level for tub rotation") which is lower than the predetermined washing water level, and rotates the washing tub at a predetermined number of rotations to perform tub rotation processing. Therefore, during tub rotation processing, the washing water will not overflow from the overflow port. In addition, the tub rotation processing stirs the washing water mixed with detergent and generates foam, so that the washing water penetrates deep into the fibers of the laundry, and the cleaning power can be increased with less water.

[0008] Furthermore, since the drum rotation process is performed during the washing process (the first half of it), a highly effective washing process can be achieved, and since the washing water does not overflow, no washing water is wasted.

[0009] (2) In the vertical washing machine described in (1), the predetermined rotational speed at which the control unit rotates the washing tub by the drive unit may be a rotational speed that exceeds the first resonance point generated in the vertical washing machine by the rotation of the washing tub.

[0010] (3) In the vertical washing machine described in (2), the predetermined rotational speed at which the control unit rotates the washing tub by the drive unit may be a rotational speed that exceeds the first resonance point generated in the vertical washing machine by the rotation of the washing tub but is less than the second resonance point.

[0011] According to these findings, the rotation speed of the washing tub during the tub rotation process is set to a rotation speed that avoids the first and second resonance points that occur in this top-loading washing machine, specifically the rotation speed in the trough between the first and second resonance points. Therefore, the shaking of the washing tub during the tub rotation process is reduced, preventing water from overflowing (due to flooding).

[0012] (4) In the vertical washing machine described in any of (1) to (3), the control unit may, in the washing process, supply water to the washing tub to the predetermined low water level, and perform a loosening process to loosen the laundry in the washing tub by rotating the rotor blade with the drive unit, and perform the tub rotation process after the loosening process.

[0013] According to this method, loosening the laundry before the drum rotation process can prevent water overflow caused by an imbalance in the laundry during the drum rotation. It can also prevent water overflow caused by the agitation of the wash water during the drum rotation process.

[0014] (5) The vertical washing machine described in any of (1) to (4) further includes a water level detection unit for detecting the water level in the outer tub, and the control unit may, before the drive unit rotates the washing tub, refrain from performing the tub rotation process if the water level in the outer tub detected by the water level detection unit is higher than a predetermined water level, or perform the tub rotation process by suppressing the rotation speed of the washing tub.

[0015] According to this system, the water level is detected before the tub rotation process is performed. If the water level in the washing tub is higher than a predetermined level (e.g., an abnormal water level or a suppression water level) that is higher than the optimal water level for tub rotation, the tub rotation process is either not performed, or the rotation speed of the washing tub is suppressed during the tub rotation process. This effectively prevents the overflow of washing water during the tub rotation process. Effects of the Invention

[0016] According to the present disclosure, in a vertical washing machine, the basic washing performance can be ensured and efficient washing can be performed. Brief Description of the Drawings

[0017] [Figure 1A] It is a diagram showing the relationship among the schematic configuration of a vertical washing machine, the water level suitable for tub rotation, the water level for tub rotation washing, and the overflow water level. [Figure 1B] It is a diagram showing the relationship between a resonance point occurring in a washing machine and the rotation speed of a washing tub. [Figure 1C] It is a diagram showing the relationship between a resonance point occurring in a washing machine and the amplitude of vibration. [Figure 2] It is a schematic vertical cross-sectional view of a vertical washing machine 1 according to an embodiment of the present disclosure. [Figure 3] It is a block diagram showing an electrical configuration of the vertical washing machine 1. [Figure 4] It is a block diagram of a processing sequence that specifically shows the content of a washing step in the vertical washing machine 1. [Figure 5] It is a flowchart showing an example of tub rotation processing. Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present disclosure will be specifically described with reference to the drawings.

[0019] FIGS. 1A to 1C are diagrams for explaining tub rotation processing (tub rotation washing) performed in the present disclosure, wherein FIG. 1A is a diagram showing the relationship among the schematic configuration of a vertical washing machine, the water level suitable for tub rotation, the water level for tub rotation washing, and the overflow water level, FIG. 1B is a diagram showing the relationship between a resonance point occurring in the washing machine and the rotation speed of the washing tub, and FIG. 1C is a diagram showing the relationship between a resonance point occurring in the washing machine and the amplitude of vibration.

[0020] Referring to FIG. 1A, a vertical washing machine 1 includes a bottomed cylindrical outer tub 3 provided in a housing 2, a bottomed cylindrical washing tub 4 coaxially accommodated with the outer tub 3 in the outer tub 3, and a rotating blade 5 provided on the inner bottom of the washing tub 4. Although not shown in the figure, water passage holes are formed in the side peripheral wall of the washing tub 4 by, for example, a large number of punching holes. When water is supplied into the washing tub 4 from a water supply unit (not shown), the water accumulated in the washing tub 4 flows out to the outer tub 3, and in a stationary state, the water level in the washing tub 4 is equal to the water level in the outer tub 3. Then, water is accumulated in the washing tub 4 and the outer tub 3 up to a tank rotation appropriate water level.

[0021] A motor 6 is attached to the outer bottom surface (lower surface) of the outer tub 3, and the rotational force of the motor 6 is transmitted to the washing tub 4 or the rotating blade 5 via a clutch mechanism 7 and shafts 17 and 18.

[0022] A drainage channel 15 is communicated with the lower surface of the outer tub 3. A drain valve 16 for opening and closing the drainage channel 15 is interposed in the drainage channel 15.

[0023] An overflow port 30 is provided at an upper portion of the outer tub 3, which allows water to overflow when water exceeding a predetermined full water level is accumulated in the outer tub 3 (the overflow water level indicated by a broken line). The overflow port 30 is connected to an upper end of an overflow channel 31, and a lower end of the overflow channel 31 joins the drainage channel 15 on a downstream side of the drain valve 16.

[0024] A water level detection unit 28 for detecting the water level of the water accumulated in the outer tub 3 is provided on an outer side portion of the outer tub 3.

[0025] When vibration is generated in the outer tub 3 due to rotation of the washing tub 4 or the like, the outer tub 3 is installed in the housing 2 via a vibration absorbing member or the like (not shown) so that the vibration is less likely to be transmitted from the outer tub 3 to the housing 2.

[0026] In Figure 1A, the optimal water level for tub rotation is shown by a dashed line. The water level when the washing water is filled to the optimal level for tub rotation and tub rotation washing is performed is shown by a double dashed line. During tub rotation washing, the washing tub 4 rotates at a predetermined speed (for example, 200 rpm can be used as the predetermined speed). As the washing tub 4 rotates, centrifugal force acts on the water accumulated in the washing tub 4, and the water in the washing tub 4 flows out from the side walls of the washing tub 4 into the outer tub 3. The water level between the washing tub 4 and the outer tub 3 then rises as shown by the double dashed line.

[0027] In this disclosure, the water level of the washing water in the tub rotation wash is set to a level lower than the overflow water level (shown by a dashed line in Figure 1A), which is the water level at which water overflows from the overflow port 30 provided in the outer tub 3.

[0028] According to the inventor's findings, when the rotation speed of the washing tub 4 is gradually increased, the outer tub 3 vibrates significantly at two specific rotation speeds. At one rotation speed, the lateral vibration of the outer tub 3 increases, while at the other rotation speed, the vertical vibration of the outer tub 3 increases. This phenomenon, where the vibration of the outer tub 3 increases at two specific rotation speeds of the washing tub 4, is thought to be due to resonance caused by the natural frequencies of the washing tub 4 and the outer tub 3.

[0029] As shown in Figure 1C, in the vertical washing machine 1 shown in Figure 1A, when performing a drum rotation wash, if the rotation speed of the washing drum 4 is gradually increased, for example, when the rotation speed of the washing drum 4 is around 100 rpm to 160 rpm (an example for a washing drum 4 with a capacity of 10 kg), the first resonance point is reached, the amplitude of the vibration becomes the first maximum amplitude, and the outer drum 3 shakes violently from side to side.

[0030] Subsequently, when the rotation speed of the washing tub 4 exceeds 160 rpm, the amplitude of the vibration of the outer tub 3 decreases and stabilizes. Then, for example, when the rotation speed of the washing tub 4 is around 240 rpm to 300 rpm (an example for a washing tub 4 with a capacity of 10 kg), a second resonance point is reached, producing a second maximum amplitude of vibration, causing the outer tub 3 to shake violently vertically.

[0031] In this disclosure, in a vertical washing machine 1, in view of the above-mentioned resonance characteristics when the washing tub 4 is rotated, as shown in Figure 1B, the rotation speed of the washing tub 4 when performing tub rotation washing is set to a predetermined rotation speed that corresponds to the trough of the vibration amplitude between the first resonance point and the second resonance point.

[0032] Specifically, as shown in Figure 1B, in the tub rotation wash cycle, the rotation speed of the washing tub 4 is set to approximately 200 rpm. However, the rotation speed of the washing tub in the tub rotation wash cycle is not limited to approximately 200 rpm; it may be any rotation speed within the range of approximately 170 rpm to 230 rpm, which corresponds to the trough of resonance.

[0033] Figure 2 is a schematic longitudinal cross-sectional view of a vertical washing machine 1 according to one embodiment of the present disclosure. The vertical washing machine 1 includes a housing 2, an outer tub 3, a washing tub 4, a pulsator 5 as an example of a rotor, a motor 6 as an example of a drive unit, and a clutch 7.

[0034] The casing 2 is made of metal, for example, and is formed in a box shape. An opening 2B is formed on the top surface 2A of the casing 2, connecting the inside and outside of the casing 2. A door 10 for opening and closing the opening 2B is provided on the top surface 2A. A display and operation unit 11, such as an LCD operation panel, may be provided around the opening 2B on the top surface 2A. The user of the top-loading washing machine 1 can select operating conditions for the washing cycle performed by the top-loading washing machine 1, or instruct the top-loading washing machine 1 to start or stop the washing cycle, by operating the display and operation unit 11. Information for the user is displayed on the display and operation unit 11.

[0035] The outer tank 3 is made of, for example, resin and is formed in a bottomed cylindrical shape. The outer tank 3 has a substantially cylindrical circumferential wall 3A arranged along the vertical direction, a bottom wall 3B that closes the hollow portion of the circumferential wall 3A from below, and a ring-shaped annular wall 3C that protrudes from the upper edge of the circumferential wall 3A toward the center of the circumferential wall 3A. An entrance / exit 3D is formed inside the annular wall 3C, communicating with the hollow portion of the circumferential wall 3A from above. The entrance / exit 3D is in communication with the opening 2B of the housing 2 from below. The annular wall 3C is provided with a door 12 for opening and closing the entrance / exit 3D. The lower surface of the annular wall 3C is provided with a guide surface 3E that slopes diagonally downward while framing the entrance / exit 3D. The bottom wall 3B is formed in a substantially horizontally extending disc shape, and a through hole 3F is formed at the center of the bottom wall 3B, penetrating the bottom wall 3B.

[0036] A water supply channel 13, connected to a tap, is connected from above to the annular wall 3C of the outer tub 3. A water supply valve 14 is provided in the middle of the water supply channel 13. The water supply valve 14 may be configured as, for example, a solenoid valve. A drain channel 15 is connected from below to the bottom wall 3B of the outer tub 3. A drain valve 16 is interposed in the middle of the drain channel 15. The drain valve 16 is opened and closed by, for example, a torque motor (not shown). When the drain valve 16 is closed and the water supply valve 14 is opened, water is supplied from the water supply channel 13 into the washing tub 4, and water is accumulated in the washing tub 4 and the outer tub 3. When the water supply valve 14 is closed, the water supply stops. When the drain valve 16 is opened, the water in the outer tub 3 is discharged outside the machine through the drain channel 15. The water supply valve 14 (and water supply channel 13) function as the water supply section.

[0037] The washing tub 4 is made of metal, such as stainless steel, and is formed in a bottomed cylindrical shape that is slightly smaller than the outer tub 3, and can accommodate laundry Q inside. The washing tub 4 is arranged coaxially within the outer tub 3. When housed within the outer tub 3, the washing tub 4 is rotatable about an axis J that forms its central axis and extends vertically. The washing tub 4 has a substantially cylindrical circumferential wall 4A arranged along the vertical direction, a bottom wall 4B that closes the hollow portion of the circumferential wall 4A from below, and a ring-shaped annular wall 4C that protrudes toward axis J along the upper edge of the circumferential wall 4A.

[0038] The inner surface of the circumferential wall 4A is the inner surface of the washing tub 4. The circumferential wall 4A is surrounded by the circumferential wall 3A of the outer tub 3. The bottom wall 4B is located at the lower end of the washing tub 4. The annular wall 4C is positioned opposite the annular wall 3C of the outer tub 3 from below. An inlet / outlet 4D is formed inside the annular wall 4C. The inlet / outlet 4D is located at the upper end of the washing tub 4, exposing the hollow portion of the circumferential wall 4A to the upper side. The inlet / outlet 4D is in communication with the inlet / outlet 3D of the outer tub 3, facing it from below. The user loads and unloads laundry Q into and out of the washing tub 4 from above through the open opening 2B, inlet / outlet 3D, and inlet / outlet 4D.

[0039] Numerous water passages 4E, formed, for example by punching holes, are provided in the circumferential wall 4A and bottom wall 4B of the washing tub 4. Water in the outer tub 3 flows back and forth between the outer tub 3 and the washing tub 4 through the water passages 4E and accumulates in the washing tub 4. Therefore, the water level in the outer tub 3 and the water level in the washing tub 4 are the same. Note that the water passages 4E may not be provided in the circumferential wall 4A, but only in the bottom wall 4B.

[0040] The bottom wall 4B of the washing tub 4 is formed in a disc shape and extends approximately parallel to the top of the bottom wall 3B of the outer tub 3, with a gap between them. A through-hole 4F is formed in the bottom wall 4B at the center of the circle, coinciding with the axis J. The bottom wall 4B is provided with a tubular support shaft 17 that extends downward along the axis J, surrounding the through-hole 4F. The support shaft 17 is inserted through the through-hole 3F in the bottom wall 3B of the outer tub 3, and the lower end of the support shaft 17 is located below the bottom wall 3B.

[0041] The pulsator 5 is formed in a disc shape with axis J as its center and is positioned on the bottom wall 4B inside the washing tub 4. Multiple blades 5A are provided on the upper surface of the pulsator 5 facing the inlet / outlet 4D of the washing tub 4, arranged radially. The pulsator 5 is provided with a rotating shaft 18 that extends downward along axis J from its center. The rotating shaft 18 is inserted through the hollow portion of the support shaft 17, and the lower end of the rotating shaft 18 is located below the bottom wall 3B of the outer tub 3.

[0042] Motor 6 is an electric motor such as an inverter motor. Motor 6 may be located inside the housing 2, on the lower surface of the outer tank 3. Motor 6 has an output shaft 19 that rotates about axis J, and outputs the generated driving force from the output shaft 19.

[0043] The clutch 7 is interposed between the lower ends of the support shaft 17 and the rotating shaft 18, respectively, and the upper end of the output shaft 19 that protrudes upward from the motor 6. The clutch 7 selectively transmits the driving force output by the motor 6 from the output shaft 19 to one or both of the support shaft 17 and the rotating shaft 18. When the driving force from the motor 6 is transmitted to the support shaft 17, the washing tub 4 rotates around axis J in response to the driving force of the motor 6. When the driving force from the motor 6 is transmitted to the rotating shaft 18, the pulsator 5 rotates around axis J in response to the driving force of the motor 6. A known transmission mechanism is used as the clutch 7. The aforementioned torque motor (not shown) may also actuate the clutch 7.

[0044] An overflow port 30 is provided at the top of the outer tank 3 to release water when the water level in the outer tank 3 exceeds a predetermined maximum level. The upper end of an overflow channel 31, which extends vertically along the outer surface of the outer tank 3, is connected to the overflow port 30. The lower end of the overflow channel 31 merges with a drainage channel 15 downstream of the drain valve 16.

[0045] In the vertical washing machine 1 according to this embodiment, the amount of water to be stored in the washing tub 4 is predetermined as a set washing water level W, as well as a suitable water level for tub rotation washing, an abnormal water level, and a suppression water level (described later).

[0046] Figure 3 is a block diagram showing the electrical configuration of the vertical washing machine 1. The vertical washing machine 1 includes a microcomputer 21 as a component of the control unit. The microcomputer 21 includes, for example, a CPU 22, memory 23 such as ROM or RAM, and a timer 24 for timing, and is built into the housing 2 (see Figure 2).

[0047] The motor 6, clutch 7, water supply valve 14, and drain valve 16 are each connected to the microcomputer 21, for example, via a drive circuit 25, and the display operation unit 11 is also connected to the microcomputer 21. The microcomputer 21 turns the motor 6 ON to drive it and turns it OFF to stop it. The microcomputer 21 can also control the rotation direction of the motor 6. Therefore, the motor 6 can rotate in the forward direction or in the reverse direction. By controlling the clutch 7, the microcomputer 21 switches the destination of the driving force of the motor 6 to either the washing tub 4 or the pulsator 5, or both. The microcomputer 21 controls the opening and closing of the water supply valve 14 and the drain valve 16. When the user operates the display operation unit 11 to select operating conditions, etc., the microcomputer 21 accepts the selection. The microcomputer 21 controls the display content of the display operation unit 11.

[0048] The top-loading washing machine 1 further includes a buzzer 26 connected to a microcomputer 21, a rotation speed reader 27, and a water level detection unit 28. The microcomputer 21 notifies the user of the start and end of the washing operation by generating a predetermined sound with the buzzer 26.

[0049] The rotation speed reading device 27 is a device that reads the rotation speed of the motor 6, more precisely, the rotation speed of the output shaft 19 of the motor 6, and may be composed of, for example, a Hall IC. The rotation speed read by the rotation speed reading device 27 is input to the microcomputer 21 in real time. Based on the input rotation speed, the microcomputer 21 controls the motor 6 to rotate at the desired rotation speed by controlling the duty cycle of the voltage applied to the motor 6. The rotation speeds of the washing tub 4 and the pulsator 5 may be the same as the rotation speed of the motor 6, or they may be values ​​obtained by multiplying the rotation speed of the motor 6 by a predetermined constant such as the reduction ratio in the clutch 7.

[0050] The water level detection unit 28 is a water level sensor that detects the water level in the outer tub 3, that is, the water level in the washing tub 4. As an example of the water level detection unit 28, a pressure-type water level sensor that detects the water level in the outer tub 3 based on the pressure inside the outer tub 3 can be used.

[0051] The microcomputer 21 performs the washing operation by controlling the operation of the motor 6, clutch 7, water supply valve 14, and drain valve 16. The washing operation includes a washing step to wash the laundry Q, a rinsing step to rinse the laundry Q after the washing step, and a dewatering step to rotate the washing tub 4 after the rinsing step to dewater the laundry Q. The top-loading washing machine 1 may also be a washer-dryer that performs a drying step to dry the laundry Q after the dewatering step.

[0052] One of the features of the vertical washing machine 1 according to this embodiment is that, in the first half of the washing process, water is supplied to the washing tub 4 to a predetermined low water level (hereinafter referred to as the "suitable water level for tub rotation") which is lower than the predetermined washing set water level W, and in that state, the washing tub 4 is rotated at a predetermined rotation speed (for example, about 200 rpm) that does not cause water to overflow from the overflow port 30, thereby performing a tub rotation process that raises the water in the outer tub 3 between the outer tub 3 and the washing tub 4.

[0053] Thus, when the drum is rotated during the (first half) of the washing process, the rotation of the drum agitates the wash water (water and detergent), generating foam and allowing the wash water (cleaning solution) to penetrate deep into the fibers of the laundry. Therefore, cleaning power can be increased with less water.

[0054] Figure 4 is a block diagram of the processing sequence that specifically shows the contents of the washing process in the vertical washing machine 1 according to this embodiment. In Figure 4, the contents of the process are shown from left to right as steps S1 to S7.

[0055] When the user places the laundry Q into the washing tub 4 and instructs the machine to start the washing cycle, the microcomputer 21 starts the washing cycle. The user may also add detergent to the washing tub 4 before or after placing the laundry Q in the machine.

[0056] Referring to the block diagram in Figure 4, first, the microcomputer 21 detects the amount of laundry Q in the washing tub 4, i.e., the load (step S1). As an example of load detection, the microcomputer 21 can detect the load by observing the variation in the rotational speed of the motor 6 when the washing tub 4 is rotated steadily at a low speed. Based on the detected load, the microcomputer 21 determines the water level W (see Figure 2) to be supplied and stored in the washing tub 4. The relationship between the water level W and the load is determined in advance through experiments and stored in memory 23.

[0057] Then, as the first water supply process of the washing cycle, the microcomputer 21 continuously opens the water supply valve 14 to supply water into the washing tub 4 (step S2). Since the drain valve 16 is closed, the water level in the washing tub 4 rises. When the water level in the washing tub 4 reaches a predetermined low water level, which is the optimal water level for tub rotation, which is lower than the water level W determined earlier, the microcomputer 21 stops the water supply by closing the water supply valve 14. This completes the water supply process.

[0058] After the water supply process, the microcomputer performs a loosening process (step S3) while water has accumulated in the washing tub 4. During the loosening process, the microcomputer 21 reverses the pulsator 5 by intermittently driving the motor 6. In this embodiment, as an example, the pulsator 5 reverses by alternately rotating forward and backward at intervals of 0.5 seconds. As a result, the laundry Q immersed in water in the washing tub 4 is loosened by the reversing pulsator 5. Therefore, the uneven distribution of the laundry Q is eliminated. Uneven distribution of laundry Q refers to the uneven distribution of laundry Q within the washing tub 4, and is also called an imbalance. After a predetermined loosening time has elapsed, the microcomputer 21 terminates the loosening process.

[0059] After the loosening process, the microcomputer 21 performs the tank rotation process (step S4).

[0060] Refer to the flowchart in Figure 5 to explain the details of the tank rotation process.

[0061] In the drum rotation process, the microcomputer 21 first determines whether the water level in the washing drum 4 is above the abnormal water level (step S41). The abnormal water level is defined as the water level in the washing drum 4 exceeding the appropriate water level for drum rotation by a certain amount. The following are some possible cases in which the water level in the washing drum 4 may reach the abnormal water level: If there is a large amount of laundry in the washing drum 4, that is, if the load is large, after water is supplied to the appropriate water level for drum rotation (step S2 in Figure 4) and then loosened (step S3 in Figure 4), water is expected to seep out from the large load and the water level in the washing drum 4 will rise.

[0062] If the water level exceeds the optimal level for tub rotation by a certain amount, performing tub rotation washing may cause the water level between the outer tub 3 and the washing tub 4 to rise too high, potentially causing the washing water to overflow from the overflow outlet 30. Therefore, in this embodiment, if the microcomputer 21 determines that the water level is above the abnormal level (YES in step S41), the tub rotation washing is not performed, and the tub rotation process is terminated.

[0063] In step S41, if the microcomputer 21 determines that the water level in the washing tub 4 is not above the abnormal water level, it further determines whether the water level in the washing tub 4 is above the suppression water level (step S42). The suppression water level is a predetermined water level in the washing tub 4 that is above the appropriate water level for tub rotation, but has not reached the abnormal water level.

[0064] When the water level is above the suppression level, if the washing tub 4 is rotated at a predetermined speed (for example, about 200 rpm) during tub rotation washing, the water level between the outer tub 3 and the washing tub 4 may rise too high, potentially causing the washing water to overflow from the overflow port 30. Therefore, in this embodiment, if the microcomputer 21 determines that the water level is above the suppression level, it suppresses the rotation speed of the motor 6 and sets the rotation speed of the washing tub 4 to, for example, about 180 rpm (step S43).

[0065] Next, the microcomputer 21 switches the clutch 7 so that the driving force of the motor 6 is transmitted from the pulsator 5 to the washing tub 4 (step S44). Then, the microcomputer 21 rotates the motor 6 so that the washing tub 4 rotates at a predetermined set rotation speed (for example, about 200 rpm) or a suppressed rotation speed (for example, about 180 rpm) (step S45).

[0066] The microcomputer 21 measures time using the timer 24 and rotates the motor 6 until a predetermined tank rotation time has elapsed (steps S46 → S45 → S46). Once the predetermined tank rotation time has elapsed, it stops the rotation of the motor 6 (step S47) and terminates the tank rotation process.

[0067] Referring again to Figure 4, after the tank rotation process (step S4) is completed, the stirring process is performed (step S5).

[0068] In this embodiment, prior to the stirring process, the microcomputer 21 detects the water level in the washing tub 4 and adds water so that the water level reaches the wash setting water level W based on the load amount determined in load amount detection (step S1).

[0069] When the washing tub 4 is filled with water up to the set washing water level W, the microcomputer 21 performs an agitation process. Specifically, the microcomputer 21 rotates the pulsator 5 by switching the clutch 7 as needed so that the driving force of the motor 6 is transmitted to the pulsator 5 (step S5). The pulsator 5 may rotate continuously in the same direction, but in this embodiment, the intermittent driving of the motor 6 causes the pulsator 5 to reverse direction alternately at intervals of 1 to 2 seconds. During the agitation process, the laundry Q in the washing tub 4 is agitated and washed by the reversing pulsator 5. The pulsator 5 may also rotate during the water supply process in step S2, which makes the detergent easier to dissolve in the water. The dirt on the laundry Q is broken down by the detergent dissolved in the water. After a predetermined agitation time has elapsed, the microcomputer 21 terminates the agitation process.

[0070] After the agitation process, the microcomputer 21 continues to perform a loosening process while water remains in the washing tub 4 (step S6). In the loosening process, the microcomputer 21 may reverse the pulsator 5 by intermittently driving the motor 6 under different conditions than those used in the agitation process. In this embodiment, as an example, the pulsator 5 reverses at a higher rotational speed than during the agitation process, alternating between forward and reverse rotation at intervals of 0.5 seconds, which is shorter than during the agitation process. As a result, the laundry Q immersed in water in the washing tub 4 is loosened by the reversing pulsator 5. Therefore, any uneven distribution of the laundry Q is eliminated. Uneven distribution of laundry Q refers to the uneven distribution of laundry Q within the washing tub 4, and is also called an imbalance. After a predetermined loosening time has elapsed, the microcomputer 21 terminates the loosening process.

[0071] Then, once the loosening process is complete, the microcomputer 21 opens the drain valve 16 and drains the wash water accumulated in the washing tub 4 and the outer tub 3 (step S7), and the washing process ends.

[0072] After the washing cycle is complete, the machine may perform intermediate spin-drying, shower rinse, rinsing, spin-drying, drying, and other processes, similar to conventional washing machines.

[0073] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. [Explanation of Symbols]

[0074] 1. Top-loading washing machine 3 Outer tank 4. Washing tub 4B Bottom wall 4D entrance / exit 4E Water hole 5. Rotary Wing (Pulsator) 6. Motor (drive unit) 13 Water supply channel (water supply section) 14. Water supply valve (water supply section) 15 Drainage Channel 16 Drain valve 21 Microcomputer (Control Unit) 27. Rotation speed reading device 28 Water level detection unit 30 Overflow outlet 31 Overflow channel Q Laundry Double Wash setting water level

Claims

1. An outer tank for storing water, A washing tub for storing laundry is rotatably arranged inside the outer tub, A rotating blade is provided at the bottom of the washing tub for agitating the laundry contained in the washing tub, A water supply unit for supplying water into the washing tub, An overflow port is provided at the top of the outer tank, which causes the water to overflow when the outer tank is filled with water above a predetermined full water level, A drive unit that generates a driving force to rotate the washing tub and the rotor blade, It includes a control unit that controls the water supply unit and the drive unit, In a top-loading washing machine, a tub rotation process is performed in which the water accumulated in the outer tub is raised between the outer tub and the washing tub by rotating the washing tub while water is accumulated in the outer tub, The control unit, in the washing process, The water supply unit supplies water to the washing tub to a predetermined low water level, which is less than the predetermined wash setting water level. To prevent water from overflowing from the overflow outlet when the washing tub rotates, the drive unit rotates the washing tub at a predetermined rotation speed to perform the tub rotation process. Top-loading washing machine.

2. The top-loading washing machine according to claim 1, wherein the predetermined rotational speed at which the control unit rotates the washing tub by the drive unit is a rotational speed that exceeds a first resonance point generated in the top-loading washing machine by the rotation of the washing tub but is less than a second resonance point.

3. The vertical washing machine according to claim 2, wherein the predetermined rotation speed is 170 rpm to 230 rpm.

4. The control unit, in the washing process, Water is supplied to the washing tub up to the predetermined low water level. The drive unit rotates the rotor blade to loosen the laundry inside the washing tub. After the loosening process, the tank rotation process is performed. A top-loading washing machine according to any one of claims 1 to 3.

5. The system further includes a water level detection unit for detecting the water level accumulated in the outer tank, The vertical washing machine according to any one of claims 1 to 3, wherein the control unit, before the drive unit rotates the washing tub, does not perform the tub rotation process if the water level in the outer tub detected by the water level detection unit is higher than a first predetermined water level.

6. The vertical washing machine according to claim 5, wherein, before the drive unit rotates the washing tub, if the water level of the outer tub detected by the water level detection unit is lower than the first predetermined water level and higher than the second predetermined water level which is lower than the first predetermined water level, the control unit suppresses the rotation speed of the washing tub and performs the tub rotation process.

Images