Drum-type washing machine

Abstract

This suppresses the extension of operating time due to retries and also prevents the dehydration process from ending prematurely. [Solution] The drum-type washing machine 100 of the present invention comprises an outer tub 17 for storing wash water, a drum 21 enclosed within the outer tub 17, a motor 22 for rotating the drum 21, a fluid balancer 21c provided on the drum 21, a vibration sensor 24 for detecting vibrations of the outer tub 17, and a control device 13 for controlling the motor 22. The control device 13 determines whether the unbalanced position of the drum 21 is a front unbalance located at the front or a rear unbalance located at the rear, based on the rotational fluctuation of the drum 21 calculated based on the rotational speed of the motor 22 and the vibration value of the outer tub 17 detected by the vibration sensor 24, and controls the motor 22 so that the rotational acceleration rate of the drum 21 at the resonant rotational speed of the outer tub 17 changes based on the determination result of the unbalanced position of the drum 21.

Description

Technical Field

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

Background Art

[0002] In the dehydration operation of a drum washing machine, the uneven distribution of clothes (hereinafter referred to as "unbalance") becomes a vibration force, and the vibration of the washing tub (hereinafter referred to as the "outer tub") increases. In a drum washing machine, when the unbalance is large, the vibration of the outer tub becomes excessive during the dehydration operation. Therefore, the dehydration operation is stopped, the unbalance is reduced, and the dehydration operation is restarted (hereinafter referred to as "retry").

[0003] Since the clothes in the drum are distributed in the front and rear of the drum, unbalance occurs in the front of the drum (hereinafter referred to as "front unbalance") and in the rear of the drum (hereinafter referred to as "rear unbalance"). The vibration of the outer tub becomes excessive at the resonance rotation speed of the outer tub in addition to the unbalance, and resonance occurs on the front side (hereinafter referred to as "front-side resonance rotation speed of the outer tub") and the rear side (hereinafter referred to as "rear-side resonance rotation speed of the outer tub") of the outer tub.

[0004] In addition, the front-side resonance rotation speed and the rear-side resonance rotation speed of the outer tub occur at different rotation speeds. When front unbalance occurs, the vibration of the outer tub becomes excessive in the front-side resonance rotation speed range of the outer tub. When rear unbalance occurs, the vibration of the outer tub becomes excessive in the rear-side resonance rotation speed range of the outer tub. In the resonance rotation speed range of the outer tub, the rate at which the rotation speed of the drum increases per second (hereinafter referred to as the "drum rotation acceleration rate") is changed to reduce the vibration of the outer tub.

[0005] In addition, a fluid balancer is provided in the front of the drum to reduce the vibration of the outer tub caused by front unbalance after the resonance rotation speed range of the outer tub. As a document regarding the change in the drum rotation acceleration rate in the resonance rotation speed range of the outer tub, for example, there is Patent Document 1.

[0006] In Patent Document 1, the acceleration rate when the amount of clothing is small (referred to as the "drum rotation acceleration rate" in this specification) is made to be greater than the acceleration rate when the amount of clothing is large, throughout the entire range including the resonance section of the outer tub (referred to as the "resonant rotation speed section of the outer tub" in this specification), the resonance section of the housing, and the post-resonance section of the housing. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 7178244 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In recent years, there has been a growing need for washing machines that can wash large amounts of clothes at once, leading to increased washing capacity (hereinafter referred to as "increased capacity"). To increase the capacity of a washing machine, it is necessary to enlarge both the drum into which the clothes are loaded and the outer tub that encloses the drum. On the other hand, if the width of the drum-type washing machine is also increased to enlarge the drum and outer tub, the washing machine itself becomes larger, worsening its portability and ease of installation. Therefore, in order to increase the capacity of a drum-type washing machine while maintaining its width, it is necessary to increase the depth, which is the front-to-back direction of the drum and outer tub.

[0009] When the drum depth is increased, clothing tends to move more easily towards the front of the drum, resulting in a greater distribution towards the front of the drum. This makes front unbalance more likely to occur even with a small amount of clothing. After the outer drum resonant rotational speed range, the liquid in the fluid balancer moves in the opposite direction to the unbalance, reducing the outer drum's front unbalance.

[0010] However, in the resonant rotational speed range of the outer tub where the vibration of the outer tub becomes excessive, the liquid flow in the fluid balancer becomes transient, causing the liquid in the fluid balancer to disperse towards the unbalanced side, which can lead to excessive vibration of the outer tub. If the vibration of the outer tub becomes excessive, in addition to the time extension due to retries, if retries occur frequently, the dewatering process may be stopped midway, potentially resulting in incomplete dewatering.

[0011] The drum-type washing machine described in Patent Document 1 changes the drum rotation acceleration rate in the resonant rotation speed range of the outer tub depending on the amount of laundry. When there is a small amount of laundry, the drum rotation acceleration rate is set higher than when there is a large amount of laundry to perform spin-drying. If the capacity is increased by expanding the depth of the drum in this configuration, pre-imbalance is more likely to occur even when there is a small amount of laundry. When pre-imbalance occurs when there is a small amount of laundry, the drum rotation acceleration rate in the resonant rotation speed range of the outer tub is large, which creates resistance to the flow of liquid in the fluid balancer, making it easier for the liquid in the fluid balancer to disperse to the unbalanced side. As a result, the distribution of liquid in the fluid balancer to the unbalanced position increases the imbalance, which can easily lead to excessive vibration of the outer tub, potentially resulting in extended operating time due to retries or failure to complete spin-drying.

[0012] The object of the present invention is to provide a drum-type washing machine that suppresses the extension of operating time due to retries and also prevents the machine from ending before the spin-drying operation is completed. [Means for solving the problem]

[0013] To achieve the above objective, the present invention provides a drum-type washing machine comprising: a housing constituting an outer shell; an outer tub provided inside the housing for storing washing water; a drum for accommodating laundry and rotatably enclosed within the outer tub with its rotation axis horizontal or tilted so that the rear side is downward; a motor for rotating the drum; a fluid balancer provided on the drum; vibration detection means for detecting vibrations of the outer tub; and a control device for controlling the motor. The control device determines whether the unbalanced position of the drum is a front unbalance or a rear unbalance based on the rotational fluctuation of the drum calculated based on the rotational speed of the motor and the vibration value of the outer tub detected by the vibration detection means, and controls the motor based on the determination result of the unbalanced position of the drum so as to change the rotational acceleration rate of the drum at the resonant rotational speed of the outer tub. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a drum-type washing machine that suppresses the extension of the operating time due to retries and also prevents the machine from ending before the spin-drying operation is completed.

[0015] Other issues, configurations, and effects not mentioned above will be clarified by the following description of the embodiments. [Brief explanation of the drawing]

[0016] [Figure 1] This is an external perspective view of a drum-type washing machine 100 according to Embodiment 1 of the present invention. [Figure 2] This is a cross-sectional view showing the internal structure of a drum-type washing machine 100 according to Embodiment 1 of the present invention, as seen from the right side. [Figure 3A] This figure shows an example of drum rotation during the dewatering process. [Figure 3B] This figure shows an example of drum rotation operation during the dewatering process when an imbalance is detected. [Figure 4] This flowchart shows the low-speed rotation range and the adhesive rotation range in the dewatering process according to Embodiment 1 of the present invention. [Figure 5] It is a flowchart for determining the dehydration process according to Embodiment 1 of the present invention. [Figure 6A] It is a flowchart for determining the position of imbalance according to Embodiment 1 of the present invention. [Figure 6B] It is a diagram showing the results of simulating the front imbalance with a weight placed in front of the drum 21 and the rear imbalance with a weight placed behind the drum 21. [Figure 6C] It is a diagram showing the magnitudes of the front imbalance, the rear imbalance, and the rotational fluctuation. [Figure 7] It is a flowchart showing the increase in the rotational speed of the drum 21 in the dehydration process according to Embodiment 1 of the present invention and for determining the dehydration process. [Figure 8A] It is a diagram showing the flow of the liquid in the fluid balancer 21c. [Figure 8B] It is a diagram showing an example of the rotational acceleration rate of the drum 21 and the rotational operation of the drum 21 in the dehydration process according to Embodiment 1 of the present invention. [Figure 8C] It is a diagram showing the vibration of the outer tub 17 when applying the rotational operation of the drum 21 in FIG. 8B. [Figure 9] It is a flowchart showing the dehydration process after the front-side resonance rotational speed of the outer tub 17 according to Embodiment 2 of the present invention. [Figure 10] It is a diagram showing an example of the rotational acceleration rate of the drum 21 and the rotational operation of the drum 21 in the dehydration process according to Embodiment 2 of the present invention.

Mode for Carrying Out the Invention

[0017] Hereinafter, embodiments of the drum washing machine according to the present invention will be described with reference to the drawings. Note that the drum washing machine of the present invention includes a drum washing and drying machine having a drying function.

[0018] In the following embodiments, the side provided with the door 2 for loading and unloading laundry is defined as "front", and the side opposite to the door side is defined as "rear". Also, the lower side of the paper surface of each figure is defined as "down", and the upper side of the paper surface is defined as "up". Also, when viewed from the side provided with the door 2, the right side is defined as "right" and the left side is defined as "left". [Examples]

[0019] First, the drum-type washing machine 100 according to Embodiment 1 of the present invention will be described using Figures 1 to 3. Figure 1 is an external perspective view of the drum-type washing machine 100 according to Embodiment 1 of the present invention. Figure 2 is a cross-sectional view showing the internal structure of the drum-type washing machine 100 according to Embodiment 1 of the present invention, viewed from the right side.

[0020] As shown in Figures 1 and 2, the drum-type washing machine 100 has an outer casing formed by a housing 1. The housing 1 consists of left and right side panels 1a, a front cover 1b, a rear cover 1c, a top cover 1d, and a bottom cover 11. The top cover 1d is provided with a water supply hose connection port 30 for supplying water from a water tap to the drum-type washing machine 100.

[0021] Door 2 is for closing the opening (not shown) for loading and unloading clothes, which is located approximately in the center of the front cover 1b, and is supported so as to be openable and closable by a hinge (not shown) provided on the front cover 1b. Door 2 opens when the door release handle 2a is pulled, disengaging the locking mechanism (not shown), and closes when it is pressed against the front cover 1b, locking the mechanism. The front cover 1b has a circular opening 1e for loading and unloading clothes, which is approximately concentric with the opening 9a of the front stay 9 and the opening 17a of the outer tub 17.

[0022] The operation / display panel 3, located on the top of the enclosure 1, is equipped with a power switch 4 and an operation switch 5. The operation / display panel 3 is electrically connected to the control device 13 located inside the enclosure 1.

[0023] The housing 1 contains an outer tub 17 for holding washing water. The lower part of the outer tub 17 is supported by dampers 29 fixed to the front, rear, left, and right sides of the housing 1. The dampers 29 consist of four dampers: a front first damper 25, a front second damper 26, a rear first damper 27, and a rear second damper 28. The upper part of the outer tub 17 is connected to an upper stay 7 by a suspension device 12, so that the outer tub 17 is supported in a suspended state from the housing 1. The suspension device 12 is made up of, for example, a coil spring.

[0024] The outer tank is equipped with a weight 40 at the front lower part, a weight 41 at the front upper part of the outer tank 17, and a weight 42 at the rear of the outer tank 17.

[0025] The outer tub 17 contains a drum 21 for storing clothes. A motor 22 for rotating the drum 21 is located at the rear of the outer tub 17. The drum 21 is rotatably supported within the outer tub 17. The motor 22 has a shaft 22a, which is the axis of rotation, that passes through the outer tub 17 and is connected to the drum 21. The motor 22 is also equipped with a Hall element for detecting the motor rotation speed, and outputs the motor rotation speed detected by the Hall element to the control device 13. By expanding the drum 21 and outer tub 17 in the front-to-back direction, the capacity is increased while maintaining the width of the housing 1.

[0026] A vibration sensor 24 (vibration detection means) for detecting vibrations of the outer tank 17 is fixed to the lower part of the outer tank 17. The value of the vibration sensor 24 is output to the control device 13.

[0027] The control device 13 appropriately controls the opening and closing of the water supply valve 31, the opening and closing of the drain valve 34a, the rotation of the motor 22, the heating of the heater (not shown), etc., in accordance with commands input by the user via the operation / display panel 3, detected values ​​from various sensors, control programs, etc., and performs each process such as washing, rinsing, dewatering, and drying. Of these processes, the details of the dewatering process according to this embodiment will be described later. The control device 13 calculates the rotational fluctuation of the drum 21 from the motor rotation speed input from the motor 22, the rotational speed of the drum 21 corresponding to that motor rotation speed, and the maximum and minimum values ​​of the rotational speed of the drum 21 during one rotation of the drum 21. The rotational speed of the drum 21 during one rotation is minimum when the clothes are rotated from top to bottom and maximum when the clothes are rotated from bottom to top. The greater the imbalance, the slower the rotational speed of the drum 21 when the clothes are rotated from bottom to top, and the faster the rotational speed of the drum 21 when the clothes are rotated from top to bottom. Therefore, the greater the imbalance, the larger the difference between the maximum and minimum rotational speeds during one rotation of the drum 21, and thus the greater the rotational fluctuation. In addition, the control device 13 calculates the vibration value of the outer tank 17 in any direction based on the vibration value input from the vibration sensor 24. Note that the rotational fluctuation in this embodiment includes rotational pulsation that fluctuates with a constant period during the rotation of the drum 21.

[0028] When the motor 22 is driven, the drum 21 rotates in both forward (clockwise when viewing the drum-type washing machine 100 from the front) and reverse (counterclockwise when viewing the drum-type washing machine 100 from the front). The rotation axis Az of the drum 21 is horizontal from the front to the rear of the drum-type washing machine 100, or inclined so that the rear side is downward. Figure 2 shows the state inclined so that the rear side is downward.

[0029] The drum 21 is provided with multiple drainage holes 21b for draining the wash water inside the drum 21 into the outer tub 17, and multiple baffles 23 (only one is shown in Figure 2) are provided on its inner circumferential surface. The multiple baffles 23 are spaced apart in the circumferential direction of the drum 21 and lift the clothes placed inside the drum 21 as the drum 21 rotates. The baffles 23 extend in the front-to-back direction of the drum 21.

[0030] A cylindrical fluid balancer 21c is provided at the front end (front side) of the drum 21, for the purpose of reducing unbalance caused by the rotation of the drum 21. The outer tank 17 is a roughly cylindrical shape with a bottom, open at the front and closed at the rear. The opening of the outer tank 17 and the input port of the housing 1 are connected by a bellows 19 that is easily expandable in the front-rear direction. The bellows 19 is made of an annular elastic member and seals the drum 21 with water when the door 2 is closed. The input port of the housing 1, the opening of the outer tank 17, and the opening of the drum 21 are in communication with each other, and clothes can be loaded into and removed from the drum 21 by opening the door 2. The outer tank 17 can be divided into the side including the opening and the side to which the motor 22 is attached.

[0031] A water supply valve 31 is located below the water supply hose connection port 30. One end of a water supply hose 32 for supplying water to the outer tank 17 is connected to the water supply valve 31. By opening the valve of the water supply valve 31, water flows from the water supply hose connection port 30 through the water supply hose 32 to the detergent container 33, and is supplied into the outer tank 17 through the front water supply hose 35 or the rear water supply hose 36.

[0032] A drain valve 34a is provided in the drainage path of the drain hose 34 located at the bottom of the outer tub 17. When the drain valve 34a is closed, the water supplied to the outer tub 17 accumulates inside the outer tub 17, and when the drain valve 34a is opened, the wash water in the outer tub 17 is drained out of the drum-type washing machine 100 through the drain hose 34.

[0033] <Basic Operation of 100 Drum-Type Washing Machines> Next, the basic operation of the drum-type washing machine 100 will be explained. In the drum-type washing machine 100, the user first presses the power switch 4 to start the machine. Then, the user pulls the door opening handle 2a to open the door 2 and puts clothes into the drum 21. After closing the door 2, the user operates the operation switch 5 to set the operation and start the machine.

[0034] When operation begins, the control device 13 controls the rotation of the drum 21 to calculate the amount of laundry before water is added. The amount of laundry is calculated based on the current value of the motor 22 when it is rotated. At this time, the larger the amount of laundry, the greater the load on the motor 22 and the larger the current value, so the amount of laundry can be determined by the current value. Then, the amount of detergent to be added is displayed on the operation / display panel 3 based on the amount of laundry. At this time, the larger the calculated amount of laundry, the more detergent to add. The user checks the display on the operation / display panel 3 and adds the predetermined amount of detergent to the detergent container 33. After that, the control device 13 starts the washing process.

[0035] During the washing process, the control device 13 opens the water supply valve 31 and supplies water supplied from the water supply hose connection port 30 to the outer tub 17 along with detergent via the water supply hose 32, detergent container 33, and either the front water supply hose 35 or the rear water supply hose 36. At this time, the larger the calculated laundry capacity, the greater the amount of water supplied during the washing process. After performing this operation for a predetermined time, the drum 21 is rotated forward, stopped, reversed, and stopped repeatedly for a predetermined time. During this time, the washing power of the clothes is enhanced as the clothes are repeatedly lifted and dropped by the baffles 23.

[0036] Next, we will explain the dewatering process. Figure 3A shows an example of drum rotation during the dewatering process. Figure 3B shows an example of drum rotation during the dewatering process when an imbalance is detected.

[0037] After the washing process, the control device 13 executes the dewatering process. In the dewatering process shown in Figure 3A, the drum 21 is initially rotated at a low speed (e.g., less than 80 r / min) so that the clothes do not stick to the drum 21. At low speeds, the clothes that have absorbed water in the washing process are lifted by the baffles 23 as the drum 21 rotates, and spread out on the inner surface of the drum 21 as they fall. Once the clothes begin to spread out, the rotation speed of the drum 21 is gradually increased (e.g., to 100 r / min) to make the clothes stick to the drum 21 (sticking rotation speed range). Once the clothes are stuck to the drum 21, the rotation speed of the drum 21 is increased, passing through the resonant rotation speed range of the outer tub 17 (e.g., 100-300 r / min) and reaching a steady-state rotation speed (e.g., 900 r / min) to centrifugeally dewater the water contained in the clothes. The resonant rotational speed range of the outer tank 17 is the value obtained by converting the natural frequency (Hz) at which the outer tank 17 resonates into rotational speed (rpm).

[0038] The outer tank 17 resonates at both its front and rear. Generally, the larger the spring component, the higher the rotational speed of the drum 21. Since a bellows 19 is provided at the front of the outer tank 17, the front resonant rotational speed range of the outer tank 17 (e.g., 200-300 r / min) is higher than the rear resonant rotational speed range of the outer tank 17 (e.g., 100-200 r / min). Unbalance occurs at the front of the drum 21 (hereinafter referred to as "front unbalance") and at the rear of the drum 21 (hereinafter referred to as "rear unbalance"). When front unbalance occurs, the vibration of the outer tank 17 increases in the front resonant rotational speed range of the outer tank 17, and when rear unbalance occurs, the vibration of the outer tank 17 increases in the rear resonant rotational speed range of the outer tank 17.

[0039] When the imbalance is large, the rotational fluctuations in the sticking rotation speed range where clothes stick to the drum 21 and the vibration of the outer tub 17 become large in the resonant rotation speed range of the outer tub 17. If the rotational fluctuation or outer tub vibration value calculated by the control device 13 exceeds a predetermined value (hereinafter referred to as "unbalance detection"), the rotation speed of the drum 21 shown in Figure 3B is stopped and the spin-drying process is repeated (hereinafter referred to as "retry"). In addition, if the number of unbalance detections or retries exceeds a predetermined number (for example, 6 times), the spin-drying process after the washing process is skipped and the process moves to the next step.

[0040] After the dewatering process, the control device 13 executes the rinsing process. In the rinsing process, the water supply valve 31 is opened, and water supplied from the water supply hose connection port 30 is supplied into the outer tub 17 via the water supply hose 32, the detergent container 33, and the front water supply hose 35 or the rear water supply hose 36. Also, as with the washing process, the amount of water supplied increases as the calculated amount of clothing increases. In the rinsing process, as with the washing process, the drum 21 repeats the operation of forward rotation, stopping, reverse rotation, and stopping. At this time, an agitation operation is performed for a predetermined time in which the clothing lifted by the baffle 23 falls.

[0041] Subsequently, the control device 13 repeats the dewatering and rinsing processes described above a predetermined number of times and proceeds to the final dewatering process. If the number of unbalance detections or retries exceeds a predetermined number during the dewatering process after the rinsing process, the control device 13 skips the dewatering process after the rinsing process and proceeds to the next process. If the number of unbalance detections or retries exceeds a predetermined number (for example, 6 times) during the final dewatering process, the control device 13 notifies the user of an error.

[0042] If the drum-type washing machine has a drying function, the control device 13 performs the drying process after the final spin-drying process. The rotation speed of the drum 21 during the drying process is set to an even lower speed than during the washing process. During the drying process, while the drum 21 rotates at a low speed, warm air is blown onto the clothes inside the drum 21 from a blower unit (not shown) to dry the clothes while reducing wrinkles.

[0043] <Drum rotation operation and dewatering control in the dewatering process> Next, the rotational movement of the drum 21 in the dewatering process and the details of the dewatering control will be explained using Figures 4 to 8.

[0044] Figure 4 is a flowchart showing the low-speed rotation range and the adhesive rotation range in the dewatering process according to Embodiment 1 of the present invention. Figure 5 is a flowchart for determining the dewatering process according to Embodiment 1 of the present invention. Figure 6A is a flowchart for determining the position of the unbalance according to Embodiment 1 of the present invention. Figure 7 is a flowchart showing the increase in the rotation speed of the drum 21 in the dewatering process and determining the dewatering process according to Embodiment 1 of the present invention.

[0045] First, the operation at the start of the dewatering process will be explained using Figure 4. When the dewatering process starts, in order to reduce tangling of the clothes before dewatering, the control device 13 performs a loosening operation by rotating the drum 21 in the forward direction, which is opposite to the rotation direction of dewatering (step S101), then stops the rotation speed of the drum 21 at 0 r / min (step S102), and proceeds to step S103.

[0046] In step S103, the control device 13 reverses the rotation of the drum 21 and increases the rotation speed of the drum 21 to the rotation speed R0 (e.g., 80 r / min) at which the clothes stick to the drum (step S103), and maintains the rotation speed R0 for time t1 to calculate the rotational variation (step S104). Since the clothes stick to the drum 21 due to centrifugal force, the rotation speed R0 at which the clothes stick to the drum 21 is determined in advance by testing, based on the rotation speed and diameter of the drum 21. Time t1 is the time during which the drum 21 rotates at least once, and the rotational variation is obtained.

[0047] After calculating the rotational fluctuation in step S104, the control device 13 performs a first unbalance determination by comparing the rotational fluctuation with a first threshold (step S105).

[0048] In step S105, if it is determined that the rotational fluctuation is greater than or equal to the first threshold (No. in step S105), the control device 13 stops the rotational speed of the drum 21 to 0 r / min (step S112) and performs a determination of the number of retries (step S113).

[0049] In step S113, if the number of retries is less than a predetermined number (Yes in step S113), the control device 13 performs the loosening operation of step S101 and retries.

[0050] In step S113, if the number of retries exceeds a predetermined number (No. in step S113), the control device 13 determines whether the dewatering process is the final dewatering process (step S114 in Figure 5). If the dewatering process is not the final dewatering process (No. in step S114), the control device 13 skips the dewatering process (step S115) and proceeds to the next process. If the dewatering process is the final dewatering process (Yes in step S114), the control device 13 notifies of a dewatering error (step S116) and terminates the operation.

[0051] In step S105, if it is determined that the rotational fluctuation is below the first threshold (Yes in step S105), the control device 13 increases the rotational speed of the drum 21 to R1 (for example, 90 r / min) (step S106).

[0052] The control device 13 maintains the rotational speed R1 for time t1 (step S107), calculates the rotational fluctuation, and performs a second unbalance determination (step S108).

[0053] In the second unbalance determination in step S108, if it is determined that the rotational fluctuation is greater than or equal to the second threshold (No. in step S108), the control device 13 stops the rotational speed of the drum 21 to 0 r / min (step S112) and performs a determination of the number of retries (step S113).

[0054] In the second unbalance determination in step S108, if the rotational fluctuation is less than the second threshold (Yes in step S108), the control device 13 increases the rotational speed of the drum 21 to R2 (for example, 100 r / min) (step S109).

[0055] The control device 13 maintains the rotational speed R2 for time t1 (step S110), calculates the rotational fluctuation, and performs a third unbalance determination (step S111).

[0056] In the third unbalance determination in step S111, if it is determined that the rotational fluctuation is greater than or equal to the third threshold (No. in step S111), the control device 13 stops the rotational speed of the drum 21 to 0 r / min (step S112) and performs a determination of the number of retries (step S113).

[0057] In the third unbalance determination in step S111, if the rotational fluctuation is less than the third threshold (Yes in step S111), the control device 13 performs the unbalance position determination shown in Figure 6A.

[0058] Here, we will explain the first threshold, the second threshold, and the third threshold. The first threshold is set to a value greater than the second threshold, and the second threshold is set to a value greater than the third threshold.

[0059] The first threshold is used to determine if the overall balance of the garment is poor, requiring the drum 21 to rotate at 0 r / min and stop, followed by a loosening operation to correct the overall balance of the garment.

[0060] The second threshold is the threshold at which, as the rotational speed of the drum 21 increases from R0 to R1, the clothes become completely attached to the drum 21, and in that state, it is determined that the rotational speed of the drum 21 can be increased.

[0061] The third threshold is the threshold at which it can be determined that an imbalance has occurred where water has been drained from the clothes, as the rotation speed of the drum 21 increases from R1 to R2, and that the rotation speed of the drum 21 can be increased up to the outer tub resonance zone of the outer tub 17.

[0062] Furthermore, the first, second, and third thresholds are determined in advance by testing.

[0063] Next, regarding the determination of the position of the unbalance in the third unbalance determination in step S111, when the rotational fluctuation is less than the third threshold (Yes in step S111), we will explain this using Figure 6A.

[0064] In step S117, the control device 13 increases the rotational speed of the drum 21 to R3 (for example, 110 r / min) and maintains it for time t2 (step S117), and calculates the vibration value of the outer tank 17 from the rotational fluctuation and vibration sensor 24. Time t2 is defined as the time during which the drum 21 rotates at least one revolution, and the rotational fluctuation and vibration value of the outer tank 17 are obtained. The control device 13 divides the rotational fluctuation calculated in step S117 by the vibration value of the outer tank 17 and performs unbalance position determination (step S118). In other words, the control device 13 calculates the rotational fluctuation while the drum 21 is rotating at a rotational speed R3 (110 r / min), which is the rear resonant rotational speed, and also obtains the vibration value of the outer tank 17.

[0065] In step S118, if the value obtained by dividing the rotational fluctuation by the vibration value of the outer tank 17 is less than a predetermined value (Yes in step S118), the control device 13 determines that there is a pre-unbalance (step S119), and proceeds to step S121 in Figure 7, increasing the rotational speed of the drum 21.

[0066] In step S118, if the value obtained by dividing the rotational fluctuation by the vibration value of the outer tank 17 is greater than or equal to a predetermined value (No. in step S118), the control device 13 determines that there is a post-unbalance (step S120), and proceeds to step S121 in Figure 7, increasing the rotational speed of the drum 21.

[0067] Here, Figure 6B shows an example of determining the position of the unbalance in step S118. Figure 6B shows the results of simulating front unbalance, where a weight is placed in front of the drum 21, and rear unbalance, where a weight is placed behind the drum 21. As mentioned above, the vibration value of the outer tank 17 in the rear resonant rotational speed section of the outer tank 17 is lower than that in the front resonant rotational speed section of the outer tank 17. Therefore, if rear unbalance occurs, the value will be greater at a low rotational speed of the drum 21, R3 (110 r / min), than if front unbalance occurs. Consequently, if rear unbalance occurs, the value obtained by dividing the rotational fluctuation by the vibration value of the outer tank 17 will be greater than that of front unbalance. By setting a predetermined value (e.g., 1.0), it is possible to determine whether front or rear unbalance is occurring.

[0068] Figure 6C shows the magnitude of the front and rear unbalances and the magnitude of the rotational fluctuation. In Figure 6C, similar to Figure 6B, the results of simulating a front unbalance with a weight placed in front of the drum 21 and a rear unbalance with a weight placed behind the drum 21 are shown. Since the size of the weight (magnitude of the unbalance) and the magnitude of the rotational fluctuation are the same for both the front and rear unbalances, the accuracy of determining the position of the unbalance due to the rotational fluctuation is low. However, as shown in Figure 6B, by combining this with the vibration value of the outer tank 17, the unbalance position can be estimated with high accuracy.

[0069] After determining the unbalanced position in step S118, the process proceeds to step S121 in Figure 7.

[0070] The control device 13 increases the rotational speed of the drum 21 (step S121) and compares the vibration value of the outer tank 17 calculated from the vibration sensor 24 with a threshold value to make a determination (step S122).

[0071] In step S122, when determining the vibration value of the outer tank 17 and the threshold, if it is determined that the vibration value of the outer tank 17 is equal to or greater than the threshold (No. in step S122), the control device 13 stops the rotation speed of the drum 21 to 0 r / min (step S112) and performs a determination of the number of retries (step S113).

[0072] In step S122, when determining the vibration value of the outer tank 17 and the threshold, if it is determined that the vibration value of the outer tank 17 is less than the threshold (Yes in step S122), the control device 13 determines whether the rotational speed of the drum 21 is 200 r / min or more, which is the rear resonant rotational speed of the outer tank 17 (step S123).

[0073] In step S123, if the rotational speed of the drum 21 is less than 200 r / min (No. in step S123), the control device 13 repeats the processes of steps S121 and S122 to bring the rotational speed of the drum 21 to 200 r / min or more.

[0074] In step S123, if the rotational speed of the drum 21 reaches 200 r / min or more (Yes in step S123), the control device 13 controls the motor 22 so that the rotational acceleration rate of the drum 21 changes based on the unbalance position determination result in step S118 (step S124).

[0075] If the unbalance position determination result in step S118 is a front unbalance (front unbalance in step S124), the control device 13 reduces the rotational acceleration rate of the drum 21 (step S125) and increases the rotational speed of the drum 21 (step S126). If the unbalance position determination result in step S118 is a rear unbalance (rear unbalance in step S124), the control device 13 increases the rotational speed of the drum 21 without reducing the rotational acceleration rate of the drum 21 (step S126). In other words, in steps S124 and S125, if the control device 13 determines that the unbalance position of the drum 21 is a front unbalance, it controls the motor 22 such that the rotational acceleration rate of the drum 21 at the front resonant rotational speed of the outer tank 17 is lower compared to when it is determined to be a rear unbalance.

[0076] In step S126, the control device 13 increases the rotational speed of the drum 21 while comparing the vibration value of the outer tank 17 calculated from the vibration sensor 24 with a threshold value and making a determination (step S127).

[0077] In step S127, when determining the vibration value of the outer tank 17 and the threshold, if it is determined that the vibration value of the outer tank 17 is equal to or greater than the threshold (No. in step S127), the control device 13 stops the rotation speed of the drum 21 to 0 r / min (step S112) and performs a determination of the number of retries (step S113).

[0078] In step S127, when determining the vibration value of the outer tank 17 and the threshold, if it is determined that the vibration value of the outer tank 17 is less than the threshold (Yes in step S127), the control device 13 determines whether the rotational speed of the drum 21 is 300 r / min or more, which is the front resonant rotational speed of the outer tank 17 (step S128).

[0079] In the determination in step S128, if the rotational speed of the drum 21 is less than 300 r / min (No. in step S128), the control device 13 increases the rotational speed of the drum 21 to 300 r / min or more while repeating the processes in steps S126 and S127.

[0080] Here, the rotational acceleration rate of the drum 21 and the vibration of the outer tank 17 in the front resonant rotational speed range of the outer tank 17 will be explained using Figure 8. Figure 8A is a diagram showing the flow of liquid in the fluid balancer 21c. First, using Figure 8A, the flow of the liquid sealed in the fluid balancer 21c provided at the front end of the drum 21 (hereinafter referred to as "liquid in the fluid balancer 21c") in the front resonant rotational speed range of the outer tank 17 will be explained.

[0081] Before the front resonant rotational speed section of the outer tank 17, the liquid in the fluid balancer 21c flows towards the unbalanced side. During the front resonant rotational speed of the outer tank 17, the phase change causes the liquid in the fluid balancer 21c to begin flowing in the opposite direction to the unbalanced side. Then, after the front resonant rotational speed of the outer tank 17, the liquid in the fluid balancer 21c moves in the opposite direction to the unbalanced side. When the liquid in the fluid balancer 21c is on the unbalanced side, the vibration of the outer tank 17 increases, and when the liquid in the fluid balancer 21c is on the opposite side of the unbalanced side, the vibration of the outer tank 17 decreases.

[0082] The rotational acceleration rate of the drum 21 and an example of the rotational operation of the drum 21 during the dewatering process will be explained using Figure 8B. Figure 8B is a diagram showing an example of the rotational acceleration rate of the drum 21 and the rotational operation of the drum 21 during the dewatering process according to Embodiment 1 of the present invention. In Figure 8B, the rotational acceleration rate of the rear-unbalanced drum 21 is shown by a solid line, and the rotational acceleration rate of the front-unbalanced drum 21 is shown by a dashed line.

[0083] In Figure 8B, when pre-unbalance is detected, the dewatering control is set to lower the rotational acceleration rate of the drum 21 in the front resonant rotational speed section of the outer tub 17 compared to when post-unbalance is detected. Outside of the front resonant rotational speed section of the outer tub 17, the rotational acceleration rate of the drum 21 is set to be the same as for pre-unbalance and post-unbalance.

[0084] Figure 8C shows the vibration of the outer tank 17 when the rotational motion of the drum 21 shown in Figure 8B is applied. In Figure 8C, the case where the rotational acceleration rate of the drum 21 is high is shown by a solid line, and the case where the rotational acceleration rate of the drum 21 is low is shown by a dashed line.

[0085] When the rotational acceleration rate of the drum 21 is high, the liquid flow resistance of the fluid balancer 21c increases at the front resonant rotational speed of the outer tub 17, making it difficult for the liquid to flow to the opposite side of the imbalance, and causing the liquid in the fluid balancer 21c to disperse on the unbalanced side. This dispersion of liquid in the fluid balancer 21c on the unbalanced side increases the vibration of the outer tub 17, and in the case of front imbalance, which is likely to occur when the drum 21 and outer tub 17 are expanded in the front-to-back direction to increase capacity, the vibration value of the outer tub 17 detected by the vibration sensor 24 is more likely to exceed the threshold, which may lead to extended operating time due to retries or failure to complete the dewatering process.

[0086] When the rotational acceleration rate of the drum 21 is low, the liquid flow resistance of the fluid balancer 21c decreases in the front resonant rotational speed section of the outer tub 17, making it easier for the liquid to flow to the opposite side of the imbalance. By allowing the liquid in the fluid balancer 21c to flow to the opposite side of the imbalance, vibration of the outer tub 17 can be reduced. This prevents the vibration value of the outer tub 17 detected by the vibration sensor 24 from exceeding a threshold in front-to-back imbalances that are likely to occur when the drum 21 and outer tub 17 are expanded in the front-to-back direction, thereby preventing the extension of operating time due to retries and preventing the process from ending without completing the dewatering.

[0087] Returning to Figure 7, in the determination of step S128, if the rotational speed of the drum 21 is 300 r / min or more (Yes in step S128), the control device 13 increases the rotational speed of the drum 21 (step S129), maintains it at the target rotational speed for a predetermined time (step S130), and terminates the dewatering process.

[0088] As described above, according to this embodiment, the position of unbalance is determined from the rotational fluctuations and the vibration value of the outer tub 17, and the rotational acceleration rate of the drum 21 corresponding to the unbalance position is changed. Therefore, vibration of the outer tub 17 in the front unbalance, which is likely to occur when the capacity is increased by expanding the drum 21 and outer tub 17 front to back, can be reduced, thereby suppressing the extension of the operating time due to retries and preventing the process from ending without completing the dewatering.

[0089] In the aforementioned Embodiment 1, a fluid balancer 21c was provided at the front end (front side) of the drum 21 to reduce the rotational acceleration rate of the drum 21 in the case of front unbalance. However, in a configuration where the fluid balancer 21c is provided at the rear side (rear side) of the drum 21, it is preferable to reduce the rotational acceleration rate of the drum 21 in the case of rear unbalance. [Examples]

[0090] Next, Example 2 will be described using Figures 9 and 10. Figure 9 is a flowchart showing the dewatering process after the front resonant rotation speed of the outer tub 17 according to Example 2 of the present invention. In Example 2, the rotational acceleration rate of the drum 21 after the front resonant rotation speed of the outer tub 17 is changed from that of Example 1. Note that the control of the drum-type washing machine 100 and the dewatering process is basically the same as in Example 1, so the differences from Example 1 will be described below.

[0091] Figure 9 shows a flowchart of the dewatering process after the drum 21 reaches a rotational speed of 300 r / min (Yes in step S129), as shown in Figure 7 of Example 1, and after the front resonant rotational speed of the outer tub 17. In Example 2, the dewatering process until the drum 21 reaches a rotational speed of 300 r / min is the same as in Example 1.

[0092] In Figure 9, if the unbalance position determination result is front unbalance (front unbalance in step S201), the control device 13 increases the rotational acceleration rate of the drum 21 (step S202) and increases the rotational speed of the drum 21 (step S203). That is, if the rotational speed of the drum 21 becomes higher than the front resonant rotational speed (300 r / min), the control device 13 controls the motor 22 so that the rotational acceleration rate of the drum 21 is higher than the rotational acceleration rate of the rear unbalanced drum 21.

[0093] If the position determination result of step 201 is a rear unbalance (rear unbalance in step S201), the control device 13 increases the rotational speed of the drum 21 without increasing the rotational acceleration rate of the drum 21 (step S203).

[0094] After increasing the rotational speed of the drum 21 in step S203, the control device 13 increases the rotational speed of the drum 21 to the target rotational speed and maintains it for a predetermined time (step S231), thereby ending the dewatering process. The unbalance position determination result in step S201 is controlled in the same way as the unbalance position determination in step S118 of Example 1.

[0095] Figure 10 shows an example of the rotational acceleration rate of the drum 21 and the rotational operation of the drum 21 in the dewatering process according to Embodiment 2 of the present invention. In Figure 10, the rotational acceleration rate of the rear-unbalanced drum 21 is shown by a solid line, and the rotational acceleration rate of the front-unbalanced drum 21 is shown by a dashed line.

[0096] If pre-unbalance is detected, the control device 13, similar to Example 1, lowers the rotational acceleration rate of the drum 21 in the front resonant rotational speed section of the outer tub 17 compared to when post-unbalance is detected, thereby reducing vibration of the outer tub 17. This helps to suppress the extension of operating time due to retries and prevents the process from ending prematurely without completing the dewatering process.

[0097] In addition, in Example 2, after the front resonant rotation speed range of the outer tank 17, the rotational acceleration rate of the drum 21 in the pre-unbalanced state is set higher than the rotational acceleration rate of the post-unbalanced state. Since the liquid in the fluid balancer 21c moves to the opposite side of the unbalance after the front resonant rotation speed of the outer tank 17, the increase in vibration of the outer tank 17 in the pre-unbalanced state after the front resonant rotation speed of the outer tank 17 can be suppressed. Furthermore, since the increase in vibration of the outer tank 17 after the front resonant rotation speed of the outer tank 17 can be suppressed, the increase in vibration of the outer tank 17 due to an increase in the rotational acceleration rate of the drum 21 can be suppressed. Moreover, by increasing the rotational acceleration rate of the drum 21 after the front resonant rotation speed of the outer tank 17, it is possible to maintain a dewatering time equivalent to that of the post-unbalanced state.

[0098] As described above, according to Example 2, in the case of pre-imbalance, the rotational acceleration rate of the drum 21 is reduced in the front resonant rotational speed section of the outer tub 17 to reduce vibration of the outer tub 17, and the rotational acceleration rate of the drum 21 is increased after the front resonant rotational speed section of the outer tub 17. Therefore, in addition to suppressing the extension of the operating time due to retries, the extension of the dewatering process time can be suppressed, and the extension of the operating time can be further suppressed.

[0099] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. For example, the embodiments described above are described in detail for the purpose of explaining the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Furthermore, it is possible to replace parts of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add configurations from other embodiments to the configuration of one embodiment. In addition, it is possible to add, delete, or replace parts of the configuration of each embodiment with other configurations. [Explanation of Symbols]

[0100] 1...Housing, 1a...Side panel, 1b...Front cover, 1c...Rear cover, 1d...Top cover, 1e...Opening, 2...Door, 2a...Door opening handle, 3...Display panel, 4...Power switch, 5...Operation switch, 7...Upper stay, 9...Front stay, 9a...Opening, 11...Lower cover, 12...Suspension device, 13...Control device, 17...Outer tub, 17a...Opening, 19...Bellows, 21...Drum, 21b...Dewatering hole, 21c...Fluid balancer, 22...Motor 22a...Shaft, 23...Baffle, 24...Vibration sensor, 25...Front first damper, 26...Front second damper, 27...Rear first damper, 28...Rear second damper, 29...Damper, 30...Water supply hose connection port, 31...Water supply valve, 32...Water supply hose, 33...Detergent container, 34...Drain hose, 34a...Drain valve, 35...Front water filling hose, 36...Rear water filling hose, 40...Weight, 41...Weight, 42...Weight, 100...Drum-type washing machine

Claims

1. The outer casing consists of a housing and The enclosure includes an outer tub for storing washing water, A drum, which accommodates laundry and is rotatably enclosed within the outer tub with its axis of rotation horizontal or tilted so that the rear side is facing downwards, A motor that rotates the drum, A fluid balancer is provided in the drum, A vibration detection means for detecting vibrations of the outer tank, A drum-type washing machine comprising a control device for controlling the motor, The control device is A drum-type washing machine characterized by determining whether the unbalanced position of the drum is a front unbalance or a rear unbalance based on the rotational fluctuation of the drum calculated based on the rotational speed of the motor and the vibration value of the outer tub detected by the vibration detection means, and controlling the motor so as to change the rotational acceleration rate of the drum at the resonant rotational speed of the outer tub based on the determination result of the unbalanced position of the drum.

2. In the drum-type washing machine according to claim 1, The fluid balancer is located in front of the drum, The drum-type washing machine is characterized in that, when the control device determines that the drum is unbalanced at the front, it controls the motor such that the rotational acceleration rate of the drum at the resonant rotational speed of the outer tub decreases compared to when it is determined that the drum is unbalanced at the rear.

3. In the drum-type washing machine according to claim 2, The resonant rotational speed of the outer tank is the rear resonant rotational speed at which the rear of the outer tank resonates, and the front resonant rotational speed that occurs at a higher rotational speed than the rear resonant rotational speed and at which the front of the outer tank resonates. The drum-type washing machine is characterized in that, when the control device determines that the drum is unbalanced at the front, it controls the motor such that the rotational acceleration rate of the drum at the front resonant rotational speed decreases compared to when it is unbalanced at the rear.

4. In the drum-type washing machine described in claim 3, The control device is characterized in that it determines the unbalanced position of the drum based on a value obtained by dividing the rotational fluctuation by the vibration value of the outer tub.

5. In the drum-type washing machine according to claim 4, The control device is characterized by calculating rotational fluctuations while the drum is rotating at the rear resonant rotational speed, and acquiring the vibration value of the outer tub.

6. In the drum-type washing machine described in claim 3, The control device is characterized in that, when the rotational speed of the drum becomes higher than the front resonant rotational speed, it controls the motor to increase the rotational acceleration rate of the drum to a level higher than the rotational acceleration rate of the rear unbalanced drum.

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