JP7473907B2 - washing machine - Google Patents

Description

The present invention relates to a washing machine that can eliminate imbalance in the spin tub while continuing to rotate the spin tub, thereby suppressing vibrations and noise caused by eccentricity of laundry during spin drying.

In typical washing machines installed in homes or laundromats, laundry tends to be unevenly distributed in the spin tub during the spin cycle, causing vibrations and noise. If the laundry is significantly unevenly distributed at that time, the amplitude of the spin tub becomes large as it spins, resulting in large vibrations and making it impossible to start the spin cycle.

Patent Document 1 discloses a technology that detects the amount and location of imbalance of clothes in the washing tub during spin-drying, and if there is imbalance, actively resolves the imbalance in the spin-drying tub by injecting water into multiple baffles that are evenly spaced around the periphery of the tub.

JP 2017-56025 A

In the washing machine of Patent Document 1, water is poured into the baffle through a water receiving ring unit fixed to the upper end of the inner circumferential surface of the spin tub. The water receiving ring unit has three water guide gutters stacked in three layers in the radial direction, and each of the three water guide gutters has a water passage that allows conditioned water to flow to one of the baffles.

The spin tub is placed inside the outer tub, and a nozzle unit capable of injecting conditioning water into each water guide gutter individually is fixed to the upper end of the outer tub. The nozzle unit has three water injection nozzles arranged above the three water guide gutter. Each water injection nozzle is aligned with the washing machine stopped so that it is positioned so that it can inject conditioning water into each water guide gutter.

If there is no eccentricity in the dehydration tank, the dehydration tank and outer tank rotate in sync, and adjustment water is properly injected from each water injection nozzle into each water guide gutter. In contrast, if there is eccentricity in the dehydration tank, the dehydration tank and outer tank will no longer rotate in sync, and adjustment water will not be properly injected from each water injection nozzle into each water guide gutter, resulting in the problem that adjustment water from each water injection nozzle will be injected into the wrong water guide gutter. In that case, it will be impossible to properly control the dehydration tank to eliminate the imbalance.

In particular, when there is eccentricity in the upper part or the center in the vertical direction inside the spin tub, or when the eccentric positions are positioned opposite each other at the top and bottom of the spin tub (when the two eccentric positions are positioned on opposite sides in the vertical direction and are offset in opposite directions in the horizontal direction), the vibration force at the top end of the spin tub causes the upper end of the outer tub to vibrate significantly, which can easily lead to problems with conditioning water from each water injection nozzle being injected into the wrong water guide. Also, in a vertical washing machine, the strength of the outer tub is relatively small, so when the spin tub rotates at a relatively low rotation speed, the outer tub resonates and the upper end of the outer tub vibrates significantly.

Therefore, the present invention provides a washing machine that can more appropriately control the spin tub to eliminate imbalances even if laundry is unevenly distributed in the washing tub during the spin cycle.

A washing machine according to the present invention comprises a dehydration tub disposed within an outer tub and having a pulsator disposed at the bottom thereof, three or more water passage pipe sections disposed at equal intervals in the circumferential direction on the inner peripheral surface of the dehydration tub and opening near the bottom and having a circulating water port formed at their upper ends, a water receiving ring unit fixed to the upper end of the dehydration tub and comprising three or more annular water guide gutters radially stacked on top of each other and each connected to the upper ends of the water passage pipe sections, a nozzle unit fixed to the upper end of the outer tub and capable of individually injecting conditioning water into each water guide gutter, acceleration detection means for detecting vibration of the outer tub, a position detection device which transmits a pulse signal in response to rotation of the dehydration tub, eccentricity detection means for detecting the amount and position of eccentricity within the dehydration tub, and a rotation detecting means for detecting the amount of eccentricity within the dehydration tub when the amount of eccentricity reaches a predetermined value during a spin cycle. and a control means for controlling the nozzle unit so that water is injected into the water pipe section corresponding to the eccentric position when the amount of eccentricity reaches a predetermined amount threshold , the nozzle unit having three or more water injection nozzles arranged above and outside each water guide gutter, and the control means controls the nozzle unit to stop injecting water into the water pipe section during the dewatering process when the amount of eccentricity detected by the eccentricity detection means becomes equal to or less than a predetermined acceleration threshold, and the acceleration threshold when the eccentric position is at the top or center in the height direction of the dewatering tank is smaller than the acceleration threshold when the eccentric position is at the bottom of the dewatering tank .

In the present invention, controlling the nozzle unit differently when the eccentric position is at the top or center in the height direction of the dehydration tub and when it is at the bottom of the dehydration tub means, for example, that at least one of the various thresholds used when controlling water injection by the nozzle unit is different when the eccentric position is at the top or center in the height direction of the dehydration tub and when it is at the bottom of the dehydration tub.

The washing machine according to the present invention comprises a dehydration tub arranged in an outer tub and having a pulsator arranged at the bottom thereof, three or more water passage pipe sections arranged at equal intervals in the circumferential direction on the inner peripheral surface of the dehydration tub and opening near the bottom and having a circulating water port at their upper ends, a water receiving ring unit fixed to the upper end of the dehydration tub and comprising three or more annular water guide gutters radially stacked on top of each other and each connected to the upper ends of the water passage pipe sections, a nozzle unit fixed to the upper end of the outer tub and capable of individually injecting conditioned water into each water guide gutter, acceleration detection means for detecting vibration of the outer tub, and a front The device is equipped with a position detection device that emits a pulse signal in response to the rotation of the dehydration tub, an eccentricity detection means that detects the amount of eccentricity and the eccentricity position within the dehydration tub, and a control means that controls the nozzle unit to inject water into the water passage pipe section corresponding to the eccentricity position when the amount of eccentricity reaches a predetermined eccentricity threshold during the dehydration process, and is characterized in that, when the rotation speed of the dehydration tub is greater than the resonant rotation speed, the eccentricity threshold when the eccentricity position is at the top or center in the vertical direction of the dehydration tub is smaller than the eccentricity threshold when the eccentricity position is at the bottom of the dehydration tub.

The washing machine according to the present invention comprises a dehydration tub arranged in an outer tub and having a pulsator arranged at the bottom thereof, three or more water passage pipe sections arranged at equal intervals in the circumferential direction on the inner peripheral surface of the dehydration tub and opening near the bottom and having a circulating water port at their upper ends, a water receiving ring unit fixed to the upper end of the dehydration tub and comprising three or more annular water guide gutters radially stacked on top of each other and each connected to the upper ends of the water passage pipe sections, a nozzle unit fixed to the upper end of the outer tub and capable of individually injecting conditioning water into each water guide gutter, acceleration detection means for detecting vibration of the outer tub, a position detection device for transmitting a pulse signal in response to rotation of the dehydration tub, and a water receiving ring unit for receiving water from the outer tub. The device is equipped with an eccentricity detection means for detecting the amount of eccentricity and the eccentricity position, and a control means for controlling the nozzle unit to inject water into the water passage pipe section corresponding to the eccentricity position during the dehydration process when the amount of eccentricity reaches a predetermined eccentricity threshold value, and the control means controls the nozzle unit to inject water into the water passage pipe section corresponding to the eccentric position during the dehydration process only when the rotation speed of the dehydration tank is equal to or lower than a predetermined upper limit rotation speed for water injection, and is characterized in that the upper limit rotation speed for water injection when the eccentric position is at the top or center in the height direction of the dehydration tank is smaller than the upper limit rotation speed for water injection when the eccentric position is at the bottom of the dehydration tank.

In the washing machine according to the present invention, when the limit amount of water that can be poured into the water passage pipe varies depending on the rotation speed of the spin tub, it is preferable that the control means controls the nozzle unit during the spin process so that the amount of water poured into the water passage pipe does not exceed the limit amount of water that corresponds to the rotation speed of the spin tub.

According to the present invention, when the eccentric position in the dehydration tank is at the top or center in the height direction of the dehydration tank, and when the eccentric position is at the bottom of the dehydration tank, there are conceivable operating conditions in which the positional relationship between the nozzle of the nozzle unit and the water conveyance bucket is likely to change. However, by performing different controls according to the eccentric position in the dehydration tank, the positional relationship between the nozzle and the water conveyance bucket is prevented from changing. This prevents the conditioned water from the nozzle unit from being poured into the wrong water conveyance gutter, and allows proper control to be performed to eliminate the imbalance state of the dehydration tank 2.

According to the present invention, when the rotation speed of the dehydration tub in the dehydration process is lower than the resonant rotation speed and the eccentric position is at the bottom of the dehydration tub, if the amount of water injected is too large, the rotation speed of the dehydration tub increases and exceeds the resonant rotation speed, and then an opposing eccentric state occurs, which may cause large vibrations. However, since the acceleration threshold is set to a relatively large value, after water injection into the water passage pipe section starts, water injection into the water passage pipe section is stopped so that water injection ends quickly before the amount of water injection becomes too large. This suppresses changes in the positional relationship between the nozzle and the water guide bucket, and prevents conditioned water from the nozzle unit from being injected into the wrong water guide gutter.

In addition, when the rotation speed of the dehydration tub during the dehydration process is equal to or exceeds the resonant rotation speed, if the eccentric position is at the top or center of the height of the dehydration tub, the vibration of the upper end of the dehydration tub is large and the positional relationship between the nozzle and the water guide barrel is likely to change, but because the acceleration threshold is set to a relatively small value, after water injection into the water pipe section begins, water injection into the water pipe section continues until the vibration of the dehydration tub becomes relatively small. This suppresses changes in the positional relationship between the nozzle and the water guide barrel, preventing conditioned water from the nozzle unit from being injected into the wrong water guide gutter.

According to the present invention, when the eccentric position is at the top or center of the spin tub in the vertical direction, the positional relationship between the nozzle of the nozzle unit and the water conveying bucket is likely to change, but because the eccentricity threshold is set relatively small, the water injection process can be started at an early stage when the positional relationship between the nozzle and the water conveying bucket is unlikely to change. This suppresses changes in the positional relationship between the nozzle and the water conveying bucket, and prevents conditioned water from the nozzle unit from being injected into the wrong water conveying trough.

According to the present invention, if the eccentric position is at the top of the dehydration tub or in the center in the height direction, when the rotation speed of the dehydration tub increases and approaches the resonant rotation speed of the outer tub, the outer tub resonates and vibrates significantly, which makes it easy for the positional relationship between the nozzle and the water conveying bucket to change. However, because the upper limit rotation speed at which water can be poured is set relatively low, water pouring into the water pipe is stopped at a low stage when the rotation speed of the dehydration tub does not approach the resonant rotation speed of the outer tub. This prevents the positional relationship between the nozzle and the water conveying bucket from changing, and prevents conditioned water from the nozzle unit from being poured into the wrong water conveying trough.

According to the present invention, during the dehydration process, the nozzle unit is controlled so that the amount of water injected into the water passage pipe does not exceed the water injection limit amount according to the rotation speed of the dehydration tank, so it is possible to prevent the nozzle unit from injecting more conditioning water than the water injection limit amount, which would otherwise result in the conditioning water being wasted.

1 is a perspective view showing the appearance of a washing machine 1 according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the configuration of the washing machine 1 of FIG. FIG. 2 is a plan view of a portion of the washing machine 1 of FIG. 1 viewed from above. 2 is a cross-sectional view of a spin-drying tub 2 of the washing machine 1 of FIG. 1. FIG. 2 is a partial vertical cross-sectional view of the washing machine 1 of FIG. 6(a) is a cross-sectional view taken along line _a1 - _a1 in FIG. 3, FIG. 6(b) is a cross-sectional view taken along line _a2 - _a2 in FIG. 3, and FIG. 6(c) is a cross-sectional view taken along line _a3 - _a3 in FIG. 7(a) is a diagram of baffle 8 formed on inner circumferential surface 2a1 of spin tub 2 as viewed from the inner circumferential side, and FIG. 7(b) is a cross-sectional view taken along line _a1 - _a1 in FIG. 7(a). FIG. 8(a) is a diagram showing the combined force of gravity and centrifugal force acting on the water surface, and FIG. 8(b) shows the change in water surface angle when the rotation speed of the spin tub 2 is changed in various ways. FIG. 2 is a block diagram of an electrical system of the washing machine 1 of FIG. FIG. 13 is a diagram illustrating an eccentricity threshold value (ma). FIG. 13 is a diagram for explaining the upper limit rotation speed (Na) at which water can be poured. FIG. 13 is a diagram illustrating an acceleration threshold (mc). 2 is a diagram for explaining a control flow in a spin-drying process of the washing machine 1 of FIG. 1. 11 is a parameter table showing the water supply valves 31a, 31b, and 31c to be opened. 4 is a schematic diagram showing an eccentric position in the dehydration tub 2. FIG. 2 is a flowchart showing a control flow in a spin-drying process of the washing machine 1 of FIG. 1 . 13 is a flowchart showing an eccentric position adjustment process. 11 is a graph showing the relationship between the acceleration obtained from the acceleration sensor 56 and the pulse signal ps obtained from the proximity switch 55. 10 is a flowchart showing a process for measuring an amount of eccentricity and an eccentric position. 13 is a flowchart showing a process of start-up determination. 1 is a flowchart showing a main dehydration process. 2 is a graph showing an overview of a spin-drying process of the washing machine 1 of FIG. 1 . 13 is a flowchart showing the process of a water injection step. 4 is a schematic diagram showing an unbalanced state in the dehydration tub 2. FIG. This is data showing the change in vibration in each imbalance state. 10 is a flowchart showing a procedure of a modified example of a spin-drying process of the washing machine 1 according to the embodiment of the present invention. 10 is a flowchart showing a procedure of a modified example of a spin-drying process of the washing machine 1 according to the embodiment of the present invention.

The washing machine 1 according to an embodiment of the present invention will be described in detail below with reference to the drawings.

Figure 1 is a perspective view showing the exterior of a vertical washing machine (hereinafter referred to as "washing machine") 1 according to an embodiment of the present invention. Figure 2 is a schematic diagram showing the configuration of the washing machine 1 of this embodiment. Figure 3 is a plan view of a part of the washing machine 1 of this embodiment seen from above. Figure 4 is a cross-sectional view of the spin tub 2 of the washing machine 1. Figure 5 is a partial vertical cross-sectional view of the washing machine 1 of this embodiment.

The washing machine 1 of this embodiment includes a washing machine main body 1a, a spin tub 2, an outer tub 3, a water receiving ring unit 5, a nozzle unit 30, a drive unit 50, and a control means 60 (see FIG. 9).

The washing machine body 1a shown in FIG. 1 has a generally rectangular parallelepiped shape. An opening 11 for loading and unloading laundry from the spin tub 2 is formed on the top surface of the washing machine body 1a, and an opening/closing lid 11a that can open and close this opening 11 is attached.

The outer tub 3 is a cylindrical member with a bottom that is disposed inside the washing machine body 1a and is capable of storing washing water inside. As shown in FIG. 2, an acceleration sensor 56 capable of detecting acceleration in three directions, the left-right direction, the up-down direction, and the front-back direction, is attached to the outer peripheral surface 3a of the outer tub 3.

The spin tub 2 is a cylindrical member with a bottom that is arranged coaxially with the outer tub 3 and is supported so as to be freely rotatable within the outer tub 3. The spin tub 2 can accommodate laundry inside and has a number of water holes in its wall surface 2a.

A pulsator (agitating blade) 4 is rotatably disposed in the center of the bottom 2c of the spin tub 2. As shown in FIG. 2, the pulsator 4 has a generally disk-shaped pulsator body 4a, a number of upper blades 4b formed on the upper surface of the pulsator body 4a, and a number of lower blades 4c formed on the lower surface of the pulsator body 4a. The pulsator 4 agitates the wash water stored in the outer tub 3 to generate a water flow.

As shown in FIG. 4, three baffles (water injection pipes) 8 serving as water passage pipes are provided on the inner peripheral surface 2a1 of the dehydration tub 2 at equal intervals (equal angles) in the circumferential direction. Each baffle 8 extends vertically from the bottom 2c to the upper end of the dehydration tub 2, and is formed to protrude from the inner peripheral surface 2a1 of the dehydration tub 2 toward the axis S1. Each baffle 8 is hollow and has an arc-shaped cross section. In this way, the shape of the baffle 8 protrudes little toward the axis S1 of the dehydration tub 2 and expands circumferentially of the dehydration tub 2, which prevents the storage space of the dehydration tub 2 from becoming narrow.

As shown in FIG. 2, the upper end of the baffle 8 is provided with a horizontally long circulating water port 80. The lower end of the baffle 8 is provided with an opening 81 that opens near the bottom 2c of the spin tub 2, more specifically, below the pulsator body 4a.

Therefore, during the washing process when the drain valve 10a (see FIG. 2) is closed and washing water is stored in the outer tub 3, the washing water agitated by the lower blade portion 4c of the pulsator 4 enters through the opening 81, splashes up inside the baffle 8, and is discharged from the circulating water port 80, showering the clothes, as shown by the arrows in FIG. 2. This action is repeated, so that the washing water circulates inside the spin tub 2. In other words, the baffle 8 has a function of circulating the washing water.

A partition piece 8a is provided near the upper end of the baffle 8, extending from the circulating water port 80 to a position close to the inner circumferential surface 2a1 of the dehydration tank 2. The partition piece 8a extends radially outward from the upper edge of the circulating water port 80 and then curves downward. A gap 8b (see Figure 2) is formed between the partition piece 8a and the inner circumferential surface 2a1 of the dehydration tank 2, and the conditioned water supplied from the water receiving ring unit 5 flows downward through the gap 8b.

As shown in Figures 3 and 5, the water receiving ring unit 5 is composed of three layers of annular water guide gutters 5a, 5b, and 5c that are open upward and are stacked radially toward the axis S1 of the dehydration tank 2, and is fixed to the upper end of the inner surface 2a1 of the dehydration tank 2 as shown in Figure 2. The water guide gutters 5a, 5b, and 5c are provided in the same number as the baffles 8, and are formed so that the conditioned water can flow to any one of the baffles 8 individually.

As shown in Fig. 5, the upper ends of the water guide gutters 5a, 5b, and 5c are located at approximately the same height, and the depths of the water guide gutters 5a, 5b, and 5c are different from each other. That is, the depths of the water guide gutters 5a, 5b, and 5c increase in the order of depth n _a of the water guide gutters 5a, depth n _b of the water guide gutters 5b, and depth n _c of the water guide gutters 5c from the outer periphery to the inner periphery. Therefore, the bottom surfaces 5 _ta , 5 _tb , and 5 _tc of the water guide gutters 5a, 5b, and 5c are located at different heights from each other, with the bottom surface 5 _ta of the water guide gutters 5a located at the highest position, and the bottom surface 5 _tb of the water guide gutters 5b and the bottom surface 5 _tc of the water guide gutters 5c located at the lowest positions from the outer periphery to the inner periphery.

The water guide gutters 5a, 5b, and 5c decrease in width (radial length) t _a1 of the water guide gutters 5a, width (radial length) t _b1 of the protrusions 6b, and width (radial length) t _c1 of the protrusions 6c from the outer periphery toward the inner periphery.

As shown in Fig. 5, the upper ends of the water guide gutters 5a, 5b, and 5c each have a protrusion 6a, 6b, and 6c that protrudes radially inward from the outer circumferential wall. The protrusions 6a, 6b, and 6c are formed around the entire circumference of the water guide gutters 5a, 5b, and 5c. The radial lengths of the protrusions 6a, 6b, and 6c are the same around the entire circumference, and from the outer circumferential side to the inner circumferential side, the radial length t _a2 of the protrusion 6a, the radial length t _b2 of the protrusion 6b, and the radial length t _c2 of the protrusion 6c decrease in that order.

When conditioning water is poured into the water guide chutes 5a, 5b, and 5c while the dehydration tank 2 is rotating, the conditioning water sticks to the outer walls of the water guide chutes 5a, 5b, and 5c due to centrifugal force. At that time, the protrusions 6a, 6b, and 6c are formed at the upper ends of the water guide chutes 5a, 5b, and 5c, so that the conditioning water is prevented from splashing out from the water guide chutes 5a, 5b, and 5c to the outside.

The protruding portion 6c of the water guide gutter 5c is the shortest, but the water guide gutter 5c is the deepest, so the conditioned water sticks to a wide area of the outer wall below the protruding portion 6c of the water guide gutter 5c with a thin thickness. In contrast, the protruding portions 6a and 6b of the water guide gutter 5a and 5b are longer than the protruding portion 6c of the water guide gutter 5c, but the water guide gutter 5a and 5b are not deeper than the water guide gutter 5c, so the conditioned water sticks to a small area of the outer wall below the protruding portions 6a and 6b of the water guide gutter 5a and 5b with a thick thickness. As a result, the dewatering tank 2 can rotate with approximately the same amount of conditioned water held inside the water guide gutter 5a, 5b, and 5c in all of the water guide gutter 5a, 5b, and 5c.

As shown in FIG. 5, the upper ends of the water guide gutters 5a, 5b, and 5c are formed with protrusions 6a, 6b, and 6c, and the upper ends of the water guide gutters 5a, 5b, and 5c are formed with annular openings 35a, 35b, and 35c arranged radially inside the protrusions 6a, 6b, and 6c, respectively. Therefore, the water injection nozzles 30a, 30b, and 30c inject adjustment water into the water guide gutters 5a, 5b, and 5c from the openings 35a, 35b, and 35c formed at the upper ends of the water guide gutters 5a, 5b, and 5c. In this embodiment, the widths (radial lengths) of the openings 35a, 35b, and 35c formed at the upper ends of the water guide gutters 5a, 5b, and 5c are formed to be the same. The width of the openings 35a, 35b, and 35c is set, for example, taking into account the diameter of the water injection nozzles 30a, 30b, and 30c so that the conditioned water from the water injection nozzles 30a, 30b, and 30c is appropriately injected into the water guide gutters 5a, 5b, and 5c.

As shown in Figures 3 and 6(a), an opening 5A that opens radially outward is formed at the lower end of the water guide gutter 5a, and the water guide gutter 5a communicates with the inside of the baffle 8.

In addition, as shown in Figs. 3 and 6(b), an opening 5B that opens radially outward is formed at the lower end of the water guide conduit 5b, and the water guide conduit 5b communicates with the inside of the baffle 8 via a water passage 5Ba that passes below the water guide conduit 5a. The water passage 5Ba extends horizontally and radially outward from the opening 5B.

In addition, as shown in Figs. 3 and 6(c), an opening 5C that opens radially outward is formed at the lower end of the water guide conduit 5c, and the water guide conduit 5c communicates with the inside of the baffle 8 via a water passage 5Ca that passes under the water guide conduits 5a and 5b. The water passage 5Ca extends horizontally and radially outward from the opening 5C.

An annular fluid balancer 12 is attached to the outer periphery of the water receiving ring unit 5. The fluid balancer 12 is similar to known fluid balancers.

7(a) is a diagram of baffle 8 formed on inner circumferential surface 2a1 of spin tub 2 as viewed from the inner circumferential side, and FIG. 7(b) is a cross-sectional view taken along line _a1 - _a1 in FIG. 7(a).

As shown in FIG. 7(b), the inner peripheral side wall of the baffle 8 has a protruding wall portion 82 protruding radially inward near the lower end. That is, a part of the inner peripheral side wall of the baffle 8 protrudes radially inward. Inside the baffle 8, as shown in FIG. 7(a) and FIG. 7(b), a water receiving plate 85 is formed protruding radially inward from the outer peripheral side wall. The water receiving plate 85 is disposed at the same height as the protruding wall portion 82, and the radial inner end portion 85a of the water receiving plate 85 is disposed inside the protruding wall portion 82. A gap is formed between the radial inner end portion 85a of the water receiving plate 85 and the tip inner peripheral surface of the protruding wall portion 82, and the adjustment water supplied to the water storage space 8a flows into the drainage space 8b through the gap.

The internal space of the baffle 8 has a water storage space 8a located above the protruding wall portion 82 on which the water receiving plate 85 is located, and a drainage space 8b located below the protruding wall portion 82. The water storage space 8a is a space for storing the conditioned water from the water guide gutters 5a, 5b, and 5c, and the drainage space 8b is a space for draining the conditioned water that flows out from the water storage space 8a. As shown in Figures 7(a) and 7(b), the radial thickness of the water storage space 8a and the radial thickness of the drainage space 8b are approximately the same, while the vertical length of the drainage space 8b is shorter than the vertical length of the water storage space 8a, and the circumferential length of the drainage space 8b is shorter than the circumferential length of the water storage space 8a. Therefore, the volume of the water storage space 8a is larger than the volume of the drainage space 8b.

The conditioning water poured into the water storage space 8a of the baffle 8 is held by the water receiving plate 85 arranged inside the protruding wall portion 82 so that it does not flow downward, and flows radially inward along the upper surface of the water receiving plate 85 inside the protruding wall portion 82. When the conditioning water is poured into the water storage space 8a of the baffle 8 while the dehydration tank 2 is rotating, the conditioning water sticks to the outer peripheral walls of the water guide gutters 5a, 5b, and 5c due to centrifugal force, so that the conditioning water is held in the water storage space 8a.

Fig. 8(a) is a diagram showing the resultant force of gravity and centrifugal force acting on the water surface in the water guide trough. In Fig. 8, when the angle of the water surface with respect to the horizontal line is θ (water surface angle θ), the gravity acting on the water surface is mg, the centrifugal force is ^mrω2 , and tan θ = ^mrω2 /mg.

8(b) shows the change in the water surface angle when the rotation speed of the spin tub 2 is changed. The radius of the spin tub 2 is 0.24 (m). For example, when the rotation speed of the spin tub 2 is 100 rpm, the angular velocity ω is 10.5. In this case, the value of ^rω2 is 26.3, and when the gravitational acceleration g is 9.8 m/ ^s2 , the water surface angle θ is 69.58 degrees.

The water surface angle θ of the conditioned water in the water storage space when the dehydration tank 2 is rotating changes depending on the rotation speed of the dehydration tank 2. That is, as shown in FIG. 8(b), when the rotation speed of the dehydration tank 2 is low, the centrifugal force is small and the water surface angle θ is relatively small, whereas when the rotation speed of the dehydration tank 2 is high, the centrifugal force is large and the water surface angle θ is relatively large.

The conditioning water poured into the baffle 8 can be maintained within the baffle 8 by the water receiving plate 85 up to the water pouring limit amount (maximum amount that can be poured) corresponding to each rotation speed of the spin-drying tank 2, but if the water pouring limit amount is exceeded, the excess conditioning water is drained through the gap formed between the radially inner end portion 85a of the water receiving plate 85 and the inner peripheral surface at the tip of the protruding wall portion 82.

The water pouring limit amount of conditioning water that can be maintained by the water receiving plate 85 in the baffle 8 described above varies depending on the water surface angle θ corresponding to each rotation speed of the spin tub 2. That is, when the rotation speed of the spin tub 2 is low, the water surface angle θ is relatively small, so the water pouring limit amount of conditioning water is small, and when the rotation speed of the spin tub 2 is high, the water surface angle θ is relatively large, so the water pouring limit amount of conditioning water is large. In the baffle 8 of this embodiment, the water pouring limit amount that can be poured into the baffle 8 varies depending on the rotation speed of the spin tub 2.

In this embodiment, the position (vertical height) and radial length of the water receiving plate 85 are set so that when the rotation speed of the dehydration tank 2 exceeds the resonant rotation speed, the center of gravity of the conditioning water stored above the water receiving plate 85 is at approximately the same height as the center of the height of the dehydration tank 2 (the center of the height of the dehydration tank 2).

For example, Figure 7(b) shows the water surface at a resonant rotation speed of 200 rpm, and the center of gravity of the conditioning water stored above the water receiving plate 85 of the baffle 8 at that time is set to be near the center of the height of the spin tank 2. Note that in Figure 7(b), when deriving the amount of conditioning water stored above the water receiving plate 85 of the baffle 8, the amount of conditioning water is subtracted because the conditioning water is not stored radially inward of the water storage space 8a.

The nozzle unit 30 injects the adjustment water into the water guide pipes 5a, 5b, and 5c individually. The nozzle unit 30 has three water injection nozzles 30a, 30b, and 30c arranged above the water guide pipes 5a, 5b, and 5c, and water supply valves 31a, 31b, and 31c connected to these water injection nozzles 30a, 30b, and 30c, respectively. The water injection nozzles 30a, 30b, and 30c are provided in the same number as the water guide pipes 5a, 5b, and 5c, and are attached to the upper end of the outer tank 3 at positions where they can inject water into the separate water guide pipes 5a, 5b, and 5c. In this embodiment, tap water is used as the adjustment water. In addition, it is also possible to adopt direction switching water supply valves as the water supply valves 31a, 31b, and 31c.

With this configuration, during the spin cycle when the drain valve 10a is opened and the washing water in the outer tub 3 is discharged from the drain outlet 10, the adjusted water injected from one of the water injection nozzles 30a, 30b, 30c of the nozzle unit 30 into the water guide gutters 5a, 5b, 5c of the water receiving ring unit 5 flows into the baffle 8.

For example, when adjustment water is injected from the water injection nozzle 30a, the adjustment water flows from the water guide 5a through the opening 5A into the baffle 8a, as shown by the arrow in FIG. 6(a). Similarly, when adjustment water is injected from the water injection nozzle 30b, the adjustment water flows from the water guide 5b through the water passage 5Ba and the opening 5B into the baffle 8b, as shown by the arrow in FIG. 6(b). When adjustment water is injected from the water injection nozzle 30c, the adjustment water flows from the water guide 5c through the water passage 5Ca and the opening 5C into the baffle 8c, as shown by the arrow in FIG. 6(c).

When the spin tub 2 is rotating at high speed, the conditioned water that flows into the baffle 8 sticks to the inner surface 2a1 of the spin tub 2 due to centrifugal force and remains there. This increases the weight of the baffle 8, changing the balance of the spin tub 2. In this way, the baffle 8 has a pocket baffle structure that can store conditioned water by centrifugal force. Then, as the spin cycle approaches its end and the rotation speed of the spin tub 2 decreases, the centrifugal force in the baffle 8 gradually weakens, and the conditioned water flows out of the opening 81 by gravity and is drained out of the outer tub 3 through the drain pipe 10. At this time, the conditioned water flows below the pulsator body 4a through the opening 81. Therefore, the conditioned water is drained without wetting the clothes above the pulsator body 4a.

The drive unit 50 shown in FIG. 2 rotates the pulley 52 and belt 53 by the motor 51, and also rotates the drive shaft 54 extending toward the bottom 2c of the spin tub 2, thereby providing driving force to the spin tub 2 and the pulsator 4, causing them to rotate. The washing machine 1 mainly rotates only the pulsator 4 during the washing process, and rotates the spin tub 2 and the pulsator 4 integrally at high speed during the spin process. In addition, a proximity switch 55 is provided near one of the pulleys 53, which can detect the passage of the mark 52a formed on the pulley 52.

Figure 9 is a block diagram showing the electrical configuration of the washing machine 1 of this embodiment. The operation of the washing machine 1 is controlled by a control means 60 including a microcomputer. The control means 60 has a central processing unit (CPU) 61 that controls the entire system, and a memory 62 is connected to the control means 60. The control means 60 causes the microcomputer to execute a program stored in the memory 62, thereby performing a predetermined operation, and the memory 62 temporarily stores data, etc., used when executing the program.

The memory 62 also stores a predetermined rotation speed (N1) lower than the resonance point (resonance rotation speed) CP of the dehydration tub 2, a first eccentricity threshold ( _ma1 ), a second eccentricity threshold ( _ma2 ), and a third eccentricity threshold ( _ma3 ) as the eccentricity threshold (ma), a first water pourable upper limit rotation speed ( _Na1 ) and a second water pourable upper limit rotation speed ( _Na2 ) as the water pourable upper limit rotation speed (Na), a first acceleration threshold ( _mc1 ), a second acceleration threshold ( _mc2 ), and a third acceleration threshold ( _mc3 ) as the acceleration threshold (mc), and a dehydration steady rotation speed, each of which is a value described in detail below. In this embodiment, the resonance point (resonance rotation speed) CP of the dehydration tub 2 is set lower than the resonance rotation speed of the outer tub 3 itself.

(Eccentricity threshold)
The eccentricity threshold (ma) is a threshold for the amount of eccentricity in the dehydration tub 2 for determining whether or not to start the process of injecting adjustment water from the water injection nozzles 30a, 30b, and 30c to the water guide gutters 5a, 5b, and 5c. Therefore, when the amount of eccentricity in the dehydration tub 2 exceeds the eccentricity threshold (ma), the injection process is performed.

10, when the rotation speed of the dehydration tub 2 is lower than the resonant rotation speed, a first eccentricity threshold (ma ₁ ) is set as the eccentricity threshold (ma) regardless of the eccentricity position within the dehydration tub 2. When the rotation speed of the dehydration tub 2 is higher than the resonant rotation speed, a second eccentricity threshold (ma ₂ ) is set when the eccentricity position within the dehydration tub 2 is at the bottom of the dehydration tub 2, and a third eccentricity threshold (ma ₃ ) is set when the eccentricity position is at the top of the dehydration tub 2 or at the center in the height direction of the dehydration tub 2. The third eccentricity threshold (ma ₃ ) is a value smaller than the second eccentricity threshold (ma ₂ ).

In other words, when the rotation speed of the dehydration tub 2 is higher than the resonant rotation speed, if there is eccentricity in the upper part or central part of the height direction within the dehydration tub 2, the vibration force at the upper end of the dehydration tub 2 will cause greater vibration at the upper end of the outer tub 3 than when there is eccentricity in the lower part of the dehydration tub 2, and the positional relationship between the water injection nozzles 30a, 30b, 30c of the nozzle unit 30 and the water guide buckets 5a, 5b, 5c will be more likely to change.Therefore, the third eccentricity threshold (ma3) is set to a value smaller than the second eccentricity threshold ( _ma2 ) so that the water injection process can be started at an early stage when the positional relationship between the water injection nozzles 30a, 30b, 30c and the water guide buckets 5a, 5b, _5c is less likely to change.

(Maximum water injection speed)
The upper limit rotation speed for water injection (Na) is the upper limit of the rotation speed of the dehydration tank 2 at which the adjustment water can be injected from the water injection nozzles 30a, 30b, 30c to the water guide gutters 5a, 5b, 5c. Therefore, when the rotation speed of the dehydration tank 2 is equal to or lower than the upper limit rotation speed for water injection (Na), the water injection process is performed according to the amount of eccentricity of the dehydration tank 2, but when the rotation speed of the dehydration tank 2 is greater than the upper limit rotation speed for water injection (Na), the water injection process is not performed regardless of the amount of eccentricity of the dehydration tank 2.

11, when the eccentric position in the dehydration tub 2 is at the bottom of the dehydration tub 2, a first water pouring upper limit rotation speed ( _Na1 ) is set as the water pouring upper limit rotation speed ( _Na2 ) is set when the eccentric position is at the top of the dehydration tub 2 or at the center in the height direction of the dehydration tub 2. The second water pouring upper limit rotation speed ( _Na2 ) is a smaller value than the first water pouring upper limit rotation speed ( _Na1 ).

In other words, if there is eccentricity in the upper part or the center of the height direction within the dehydration tub 2, when the rotation speed of the dehydration tub 2 increases and approaches the resonant rotation speed of the outer tub 3, the outer tub 3 will resonate and vibrate greatly, which will easily change the positional relationship between the water injection nozzles 30a, 30b, 30c and the water guide barrels 5a, 5b, 5c.Therefore, the second upper limit rotation speed for water injection (Na2) is set to a value smaller than the first upper limit rotation speed for water injection ( _Na1 ) so that water injection into the baffle 8 is stopped at a low stage before the rotation speed of the dehydration tub 2 approaches the resonant rotation speed of the outer tub ₃ .

(Acceleration Threshold)
The acceleration threshold (mc) is a threshold for the amount of eccentricity in the dehydration tub 2 when the water injection process is terminated after the injection of adjustment water from the water injection nozzles 30a, 30b, 30c to the water guide gutters 5a, 5b, 5c is started. Therefore, after the water injection process is started, if the amount of eccentricity in the dehydration tub 2 becomes equal to or less than the predetermined acceleration threshold (mc), the water injection process is terminated.

As the acceleration threshold (mc), as shown in Figure 12, when the rotation speed of the dehydration tub 2 is lower than the resonant rotation speed, a first acceleration threshold ( _mc1 ) is set when the eccentric position within the dehydration tub 2 is at the bottom of the dehydration tub 2, and a second acceleration threshold ( _mc2 ) is set when the eccentric position is at the top of the dehydration tub 2 or at the center of the height of the dehydration tub 2.
The first acceleration threshold (mc ₁ ) is a value greater than the second acceleration threshold (mc ₂ ).

In other words, as the rotation speed of the dehydration tank 2 increases, the center of gravity of the water poured into the baffle 8 changes (becomes higher). Therefore, if the eccentric position within the dehydration tank 2 is at the bottom of the dehydration tank 2, pouring in too much water will result in an opposing eccentric state due to the increase in rotation speed. Therefore, the first acceleration threshold ( _mc1 ) is set to a value greater than the second acceleration threshold ( _mc2 ) so that water pouring is completed quickly without pouring in too much water at a low rotation speed.

Furthermore, when the rotation speed of the dehydration tub 2 is higher than the resonant rotation speed, the third acceleration threshold value (mc ₃ ) is set regardless of the eccentric position within the dehydration tub 2 .

The central control unit 61 outputs a control signal to the rotation speed control unit 63, which in turn outputs the control signal to the motor control unit (motor control circuit) 64 to control the rotation of the motor 51. The rotation speed control unit 63 receives a signal indicating the rotation speed of the motor 51 from the motor control unit 64 in real time, which serves as a control element.

The unbalance amount detection unit 65 is connected to the acceleration sensor 56. The unbalance position detection unit 66 is connected to the acceleration sensor 56 and the proximity switch 55. In this embodiment, the unbalance amount detection unit 65 and the unbalance position detection unit 66 constitute the eccentricity detection means.

As a result, when the proximity switch 55 detects the marker 52a (see Figure 2), the unbalance amount detection unit 65 calculates the amount of eccentricity (M) of the spin tub 2 from the magnitude of the left-right, up-down, and front-back acceleration obtained from the acceleration sensor 56, and outputs this amount of eccentricity (M) to the unbalance amount determination unit 67.

The unbalance position detection unit 66 calculates the angle of the unbalance direction from the signal indicating the position of the marker 52a input from the proximity switch 55, and outputs an unbalance position signal indicating the eccentric position (N) to the water injection control unit 68. Here, the angle of the unbalance direction is the relative angle with respect to the baffle 8 in the circumferential direction of the axis S1. In this embodiment, as an example, as shown in FIG. 16, the midpoint between the three baffles 8(B) and 8(C) arranged at equal angular intervals around the axis S1 is set to 0° to indicate the relative angle between the eccentric position and the three baffles 8(A), 8(B), and 8(C).

When the water injection control unit 68 receives signals indicating the eccentricity amount (M) and eccentricity position (N) from the unbalance amount determination unit 67 and the unbalance position detection unit 66, it determines the baffle 8 to which water should be supplied and the amount of water to be supplied based on a control program stored in advance. The water injection control unit 68 then opens the selected water supply valves 31a, 31b, and 31c to start injecting the adjusted water W. When the eccentricity amount (M) in the spin tank 2 exceeds a predetermined standard, the water injection control unit 68 starts injecting the adjusted water W from the water injection nozzle 30a selected based on the calculation of the eccentricity amount (M) into at least one of the water guide gutters 5a, 5b, and 5c of the water receiving ring unit 5, and stops injecting the adjusted water W when the eccentricity amount (M) falls below the predetermined standard.

As described above, in the baffle 8 of this embodiment, the water injection limit amount that can be injected into the baffle 8 changes depending on the rotation speed of the spin-drying tank 2. Therefore, the water injection control unit 68 can measure the amount of water injected into the baffle 8, and during the spin-drying process, controls the nozzle unit 30 so that the amount of water injected into the baffle 8 does not exceed the water injection limit amount according to the rotation speed of the spin-drying tank 2.

As shown in FIG. 13, for example, when the laundry clump D(X) causing the eccentricity is between baffles 8(B) and 8(C) of the spin tub 2, the water injection control unit 68 controls the nozzle unit 30 to supply adjustment water W to baffle 8(A). When the laundry clump D(Y) is near baffle 8(A), the water injection control unit 68 controls the nozzle unit 30 to supply adjustment water W to both baffles 8(B) and 8(C).

The central control unit 61 opens the water supply valves X and Z as shown in the parameter table in FIG. 14. In this embodiment, the eccentric position (N) is determined by dividing the spin tub 2 into six equal parts in the circumferential direction as shown in FIG. 15, and is classified into two cases: an eccentric position (N) that determines one baffle 8 to which water should be poured, and an eccentric position (N) that determines two baffles 8 to which water should be poured.

The area Y of the eccentric position (N) that identifies one baffle 8 to which water should be injected is the area (P(A)), (P(B)), and (P(C)). The area Y of the eccentric position (N) required to eliminate the eccentricity is the area (P(AB)), (P(BC)), and (P(CA)). The angles of the areas (P(A)), (P(B)), and (P(C)) centered on the axis S1 are set to 20°, and the angles of the areas (P(AB)), (P(BC)), and (P(CA)) centered on the axis S1 are set to 100°.

(Pre-dehydration process)
The pre-spin step, which is related to the first half of the spin step, will be described with reference to Fig. 16. Fig. 16 is a flow chart showing the pre-spin step, which is related to the first half of the spin step.

In this embodiment, when the central control unit 61 receives an input signal from a spin button (not shown) or a signal indicating that the spin cycle should be started during a washing course, it proceeds to step SP1 and starts the pre-spin cycle.

<Step SP1>

In step SP1, the central control unit 61 loosens and inverts the dehydration tub 2, and then increases the rotation speed of the dehydration tub 2 to a predetermined rotation speed (N1) that is lower than the resonance point CP of the dehydration tub 2. When the rotation speed of the dehydration tub 2 reaches the predetermined rotation speed (N1), the process proceeds to step SP2. In this embodiment, the predetermined rotation speed (N1) is set to 150 rpm, which is lower than the resonance point CP of the dehydration tub 2, which is approximately 200 rpm.

<Step SP2>

In step SP2, the central control unit 61 executes control to cause the eccentricity detection means to calculate the amount of eccentricity (M) and the eccentricity position θ1 based on the acceleration signal provided by the acceleration sensor 56. To be more specific, the central control unit 61 causes the means to calculate the amount of eccentricity (M) for each direction based on the acceleration signals relating to the left-right direction, the up-down direction, and the front-back direction obtained from the acceleration sensor 56, for example.

<Step SP3>

The central control unit 61 compares the calculated eccentricity amount (M) with the eccentricity amount threshold (ma) stored in the memory 62, and judges whether M<ma is satisfied, and performs start-up judgment. If the central control unit 61 judges that M<ma is satisfied, the process proceeds to step SP4, and if it judges that M<ma is not satisfied, the process proceeds to step SP5. Here, in step SP3, the first eccentricity amount threshold (ma ₁ ) is used as the eccentricity amount threshold (ma), which is a threshold assuming a case where the laundry is so skewed that it is difficult to reduce the eccentricity amount (M) to a level that allows the rotation speed of the spin tub 2 to be increased to the steady spin rotation speed even if the adjustment water W is supplied to the baffle 8. In other words, when the process proceeds to step SP5, it means that the eccentricity amount (M) is so large that it is difficult to complete the spin process even if the adjustment water W is supplied to the baffle 8.

The eccentricity threshold (ma) will be further explained. In this embodiment, the acceleration sensor 56 is capable of detecting acceleration in the left-right, up-down, and front-back directions. Different eccentricity thresholds (ma-x, ma-z, ma-y) are set for each of the acceleration signals in the left-right, up-down, and front-back directions.

<Step SP4>

In step SP4, the central control unit 61 increases the rotation speed of the spin tub 2 when the eccentricity amount (M) calculated in step SP2 is smaller than the eccentricity amount threshold (ma). The central control unit 61 also continuously controls the measurement of the eccentricity amount and eccentricity position while increasing the rotation speed of the spin tub 2. Here, "continuously" does not necessarily mean that it is performed continuously without interruption. Of course, it is also possible to control the measurement of the eccentricity amount and eccentricity position intermittently when the rotation speed of the spin tub 2 has increased to any number of rotation speeds up to the steady-state spin rotation speed.

In step SP5, the central control unit 61 controls the imbalance correction process.

The control of the unbalance correction process shown in step SP5 will be described with reference to FIG. 17. FIG. 17 is a flowchart showing the steps of the unbalance correction process.

First, if step SP3 determines that the eccentricity amount (M) is large enough that it is difficult to reduce, the rotation of the spin tub 2 is stopped (step SP51). Then, water is supplied to the spin tub 2, and the pulsator 4 is driven to agitate the laundry in the spin tub 2 and eliminate uneven distribution of the laundry (step SP52). Then, the process returns to step SP1.

(Calculation of eccentricity amount and eccentricity position)
The procedure for calculating the eccentric position θ1 shown in step SP2 will be described with reference to FIGS.

In this embodiment, during the spin-drying process, the time difference t1 between any point in the signal related to acceleration indicating at least one period t2 of the spin-drying tub 2 transmitted from the acceleration sensor 56 and the timing at which the pulse signal ps is transmitted from the proximity switch 55 is calculated, and the eccentric position θ1 in the circumferential direction within the spin-drying tub 2 is calculated from the relationship between the time difference t1 and the rotation speed of the spin-drying tub 2. Control is performed to reduce the amount of eccentricity (M) based on the calculated eccentric position θ1, and one of the signals from the acceleration sensor 56 is used to calculate the eccentric position θ1.

Figure 18 is a graph showing the relationship between information indicating the change in acceleration over time calculated based on the acceleration and the pulse signal ps obtained from the proximity switch 55. For convenience in Figure 18, the eccentric position θ1 is calculated from the time difference t1 between the maximum value (Ymax) of the acceleration in the vertical direction obtained from the acceleration sensor 56 and the pulse signal ps. Note that in the present embodiment shown in Figure 18, as an example, the eccentric position θ1 is calculated from the maximum value (Ymax) and minimum value (Ymin) of the acceleration. However, in other embodiments of the present invention, the eccentric position θ1 may be calculated from one or more of the zero point of acceleration, the maximum value (Ymax), and the minimum value (Ymin) of the acceleration.

Figure 19 is a flowchart showing the processing steps for measuring the amount of eccentricity and the eccentricity position.

<Step SP21>

In step SP21, the central control unit 61 detects acceleration data (MX, MY, MZ) relating to the left-right, up-down, and front-back directions from the acceleration sensor 56.

<Step SP22>

In step SP22, the central control unit 61 performs a calculation process to determine the maximum values (Xmax, Ymax, Zmax) and minimum values (Xmin, Ymin, Zmin) of the acceleration data (MX, MY, MZ) from the acceleration data (MX, MY, MZ) obtained from the acceleration sensor 56 and the pulse signal ps, which is an interrupt signal from the proximity switch 55.

<Step SP23>

In step SP23, the central control unit 61 calculates and determines the value of one period t2, which is the time it takes for the spin tub 2 to rotate once, from the interval between multiple pulse signals ps, which are interrupt signals from the proximity switch 55.

<Step SP24>

In step SP24, the central control unit 61 calculates and determines the time difference t1 from the multiple pulse signals ps, which are interrupt signals from the proximity switch 55, and the maximum values (Xmax, Ymax, Zmax) of the acceleration data (MX, MY, MZ) obtained in step SP22. In step SP24, the central control unit 61 calculates the time difference t1Y, which is the time difference t1 in the up-down direction shown in FIG. 18, as well as the time differences t1X and t1Z in the left-right and front-back directions.

<Step SP25>

In step SP25, the central control unit 61 calculates and determines the eccentricity amounts Mx, My, Mz in the left-right, up-down, and front-back directions, which are the eccentricity amounts (M), from the maximum values (Xmax, Ymax, Zmax) and minimum values (Xmin, Ymin, Zmin) of the acceleration data (MX, MY, MZ) obtained in step SP22. In this embodiment, the eccentricity amounts Mx, My, Mz are determined from the difference between the maximum values (Xmax, Ymax, Zmax) and the minimum values (Xmin, Ymin, Zmin).

<Step SP26>

In step SP26, the central control unit 61 calculates and determines the eccentric positions θX1, θY1, and θZ1 in the left-right, up-down, and front-rear directions, respectively, using the one period t2 obtained in step SP23 and the time difference t1 obtained in step SP24 using the following equations.
θX1 = t1X × 360 ÷ t2
θY1=t1Y×360÷t2
θZ1 = t1Z × 360 ÷ t2

(Start-up judgment)
The start-up determination shown in step SP3 will be described with reference to Fig. 20. Fig. 20 is a flow chart showing the procedure of the start-up determination.

<Step SP31>

In step SP31, the central control unit 61 selects the larger eccentricity amount (M) from the left-right eccentricity amount Mx and the front-rear eccentricity amount Mz determined in step SP25. For ease of explanation, in this embodiment, the selected eccentricity amount (M) is referred to as eccentricity amount Mxz.

<Step SP32>

In step SP32, the central control unit 61 determines whether the amount of eccentricity Mxz exceeds the threshold mxz, which is the eccentricity threshold (ma). If the amount of eccentricity Mxz is below the threshold mxz, the central control unit 61 proceeds to step SP33. If the amount of eccentricity Mxz exceeds the threshold mxz, the central control unit 61 determines that startup is not possible and proceeds to step SP5 to perform eccentricity adjustment processing.

<Step SP33>

In step SP33, the central control unit 61 determines whether the amount of eccentricity My in the vertical direction exceeds the threshold my, which is the eccentricity threshold (ma). If the amount of eccentricity My is below the threshold my, the central control unit 61 determines that start-up is possible. In this case, it increases the rotation speed of the spin tub 2. If the amount of eccentricity My is above the threshold my, the central control unit 61 determines that start-up is not possible, and proceeds to step SP5 to perform eccentricity adjustment processing.

(Dehydration process)
Hereinafter, the control of the main dehydration process from step SP4 onward will be described with reference to Fig. 21. Fig. 21 is a flow chart showing the procedure of the main dehydration process.

<Step SP51>

In step SP51, the central control unit 61 increases the rotation speed of the spin tub 2 by 20 rpm per second until the rotation speed reaches 400 rpm. While performing step SP51, the central control unit 61 also executes step SP6 in parallel.
<Step SP52>

In step SP52, the central control unit 61 judges whether the rotation speed of the spin tub 2 has reached 400 rpm. If the rotation speed has not reached 400 rpm, the central control unit 61 proceeds to step SP51. If the rotation speed has reached 400 rpm, the central control unit 61 proceeds to step SP63.
<Step SP53>

In step SP53, the central control unit 61 increases the rotation speed of the spin tub 2 by 5 rpm per second until the rotation speed reaches 600 rpm. While performing step SP53, the central control unit 61 also executes step SP6 in parallel.

<Step SP54>

In step SP54, central control unit 61 determines whether the rotation speed of spin tub 2 has reached 600 rpm. If the rotation speed has not reached 600 rpm, central control unit 61 proceeds to step SP53. If the rotation speed has reached 600 rpm, central control unit 61 proceeds to step SP55. Here, the acceleration when the rotation speed of spin tub 2 increases from 400 to 600 rpm is lower than in other rotation ranges because the amount of water dewatered from the laundry is greater in this rotation range than in other rotation ranges, and unnecessary noise caused by the water being dewatered is reduced.
<Step SP55>

In step SP55, the central control unit 61 increases the rotation speed of the spin tub 2 by 20 rpm per second until the rotation speed reaches 800 rpm. While performing step SP55, the central control unit 61 also executes step SP6 in parallel.
<Step SP56>

In step SP56, the central control unit 61 determines whether the rotation speed of the spin tub 2 has reached 800 rpm. If the rotation speed has not reached 800 rpm, the central control unit 61 proceeds to step SP55. If the rotation speed has reached 800 rpm, the central control unit 61 proceeds to step SP57.

<Step SP57>

In step SP57, when the rotation speed of the spin tub 2 reaches 800 rpm, which is the normal spin speed, the central control unit 61 continues the spin process and ends the wash after confirming that a predetermined time has elapsed. In other words, the central control unit 61 rotates the spin tub 2 at the normal spin speed for a predetermined time, as in the spin process of a normal wash, to perform the spin process. The spin process is then ended. Then, when the spin process ends and the spin tub 2 begins to decelerate, and the centrifugal force falls below the acceleration of gravity, the conditioning water W in the baffle 8 flows out and is drained.

Figure 22 is a graph showing an overview of the spin-drying process of the washing machine 1 of this embodiment. In Figure 22, the vertical axis shows the rotation speed of the spin-drying tub 2, and the horizontal axis shows time. In Figure 22, the solid line shows the behavior of the rotation speed when the rotation speed of the spin-drying tub 2 reaches the steady-state spin-drying rotation speed without pouring water into the baffle 8. Also in Figure 22, the upper imaginary line shows the behavior of the rotation speed when the rotation speed reaches the steady-state spin-drying rotation speed after pouring water into the baffle 8 only once, and the lower imaginary line shows the behavior of the rotation speed of the spin-drying tub 2 in step SP5.

(Water injection process)
The water pouring step shown in step SP6 will be described with reference to Fig. 23. Fig. 23 is a flow chart showing an outline of the water pouring step.

In step SP6, the central control unit 61 determines whether the eccentricity amount (M) calculated in step SP2 shown in FIG. 19 is greater than a preset eccentricity amount threshold (ma). When the eccentricity amount (M) is less than the eccentricity amount threshold (ma), the central control unit 61 does not inject water into the baffle 8 and proceeds to the main spin-drying process of FIG. 21. When the eccentricity amount (M) is greater than the eccentricity amount threshold (ma), the central control unit 61 determines the position of the eccentricity position (N) in the height direction of the spin-drying tank 2 (eccentricity position height determination). Based on the height of the eccentricity position, the central control unit 61 determines the acceleration threshold (mc), the upper limit rotation speed for water injection (Na), and the eccentricity amount threshold (ma). After that, the central control unit 61 injects water into the baffle 8 in the water injection process, and after the eccentricity amount (M) becomes lower than the acceleration threshold (mc), it ends the injection of water into the baffle 8 and proceeds to the main spin-drying process of FIG. 21.

In the water injection process of this embodiment, as described above, the eccentricity amount and eccentricity position measurement process is continuously performed after the rotation speed of the spin tank 2 reaches 150 rpm, and the eccentricity position height determination process, which is step SP602, and the water injection process, which is step SP612, are mainly performed.

<Step SP601>

In step SP601, the central control unit 61 determines whether the amount of eccentricity (M) calculated in step SP2 exceeds the amount of eccentricity threshold (ma). If the amount of eccentricity (M) exceeds the amount of eccentricity threshold (ma), the process proceeds to step SP602. If the amount of eccentricity (M) is below the amount of eccentricity threshold (ma), the water injection process ends. In step SP601, the first amount of eccentricity threshold (ma ₁ ) is used as the amount of eccentricity threshold (ma).

<Step SP602>

In step SP602, the central control unit 61 determines where the eccentric position (N) is located in the height direction of the dehydration tub 2 (eccentric position height determination). Specifically, the central control unit 61 determines whether the eccentric position (N) is located at the top of the dehydration tub 2, at the center of the dehydration tub 2 in the height direction, or at the bottom of the dehydration tub 2. The method for determining the eccentric position height will be explained later.

<Step SP603>

In step SP603, the central control unit 61 determines whether the rotation speed of the dehydration tub 2 is smaller than the resonant rotation speed. If the rotation speed of the dehydration tub 2 is smaller than the resonant rotation speed, the process proceeds to step SP604. If the rotation speed of the dehydration tub 2 is greater than the resonant rotation speed, the process proceeds to step SP605.

<Step SP604>

In step SP604, the central control unit 61 determines the acceleration threshold (mc) based on the eccentric position height determined in step SP602. Specifically, if the eccentric position is in the lower part of the spin tub 2, the central control unit 61 determines the acceleration threshold (mc) to be the first acceleration threshold (mc ₁ ), and if the eccentric position is in the upper part or the center in the height direction of the spin tub 2, the central control unit 61 determines the acceleration threshold (mc) to be the second acceleration threshold (mc ₂ ). Then, the process proceeds to step SP612.

<Step SP605>

In step SP605, the central control unit 61 determines the upper limit rotation speed at which water can be poured (Na) based on the eccentric position height determined in step SP602. Specifically, when the eccentric position is at the bottom of the dehydration tub 2, the central control unit 61 determines the upper limit rotation speed at which water can be poured (Na) to be the first upper limit rotation speed at which water can be poured (Na ₁ ), and when the eccentric position is at the top of the dehydration tub 2 or in the center in the height direction, the central control unit 61 determines the upper limit rotation speed at which water can be poured (Na) to be the second upper limit rotation speed at which water can be poured (Na ₂ ).

<Step SP606>

In step SP606, the central control unit 61 determines an eccentricity threshold (ma) based on the eccentricity position height determined in step SP602. Specifically, if the eccentricity position is in the lower part of the spin tub 2, the central control unit 61 determines the eccentricity threshold (ma) to be the second eccentricity threshold (ma ₂ ), and if the eccentricity position is in the upper part or the center in the height direction of the spin tub 2, the central control unit 61 determines the eccentricity threshold (ma) to be the third eccentricity threshold (ma ₃ ). Then, the process proceeds to step SP607.

<Step SP607>

In step SP607, the central control unit 61 determines the acceleration threshold (mc) to be the third acceleration threshold (mc). Then, the process proceeds to step SP608.

<Step SP608>

In step SP608, the central control unit 61 determines whether the rotation speed of the spin tub 2 is equal to or lower than the first upper limit rotation speed at which water can be poured ( _Na1 ) determined in step SP605. If the rotation speed of the spin tub 2 is equal to or lower than the first upper limit rotation speed at which water can be poured ( _Na1 ), water pouring can be performed, and the process proceeds to step SP609. If the rotation speed of the spin tub 2 is higher than the first upper limit rotation speed at which water can be poured ( _Na1 ), water pouring cannot be performed, and the water pouring process is terminated.

<Step SP609>

In step SP609, the central control unit 61 determines whether the amount of eccentricity (M) calculated in step SP2 exceeds the amount of eccentricity threshold (ma). If the amount of eccentricity (M) exceeds the amount of eccentricity threshold (ma), the process proceeds to step SP610. If the amount of eccentricity (M) is below the amount of eccentricity threshold (ma), the water injection process is terminated. In step SP609, when the eccentricity position is at the bottom of the spin tub 2, the second eccentricity threshold ( _ma2 ) is used as the amount of eccentricity threshold (ma), and when the eccentricity position is at the top of the spin tub 2 or at the center in the height direction, the third eccentricity threshold ( _ma3 ) is used.

<Step SP610>

In step SP610, the central control unit 61 performs a water injection process while maintaining the rotation speed of the spin tub 2 without increasing it. Then, the process proceeds to step SP611.

<Step SP611>

In step SP611, the central control unit 61 determines whether the amount of eccentricity (M) exceeds the acceleration threshold (mc). If the amount of eccentricity (M) exceeds the acceleration threshold (mc), the process proceeds to step SP610 and the water injection process continues. If the amount of eccentricity (M) is below the acceleration threshold (mc), the water injection process ends.

In step SP611, when the rotation speed of the dehydration tub 2 is lower than the resonant rotation speed, a first acceleration threshold ( _mc1 ) is used as the acceleration threshold (mc) if the eccentric position is at the bottom of the dehydration tub 2, and a second acceleration threshold ( _mc2 ) is used if the eccentric position is at the top or center in the height direction of the dehydration tub 2. When the rotation speed of the dehydration tub 2 is higher than the resonant rotation speed, a third acceleration threshold ( _mc3 ) is used.

(Eccentricity position height determination)
The method of determining the eccentricity position height shown in step SP602 will be described with reference to FIGS.

As shown in Figure 24, there are three possible types of unbalanced states for the spin tub 2. Figures 24(a) to 24(c) show the eccentric positions in the circumferential direction and the height direction (up and down) in the three types of unbalanced states.

Unbalanced state a is a state in which the eccentric position is at the top of the dehydration tank 2, unbalanced state b is a state in which the eccentric position is at the center of the height of the dehydration tank 2, and unbalanced state c is a state in which the eccentric position is at the bottom of the dehydration tank 2.

The upper part of the dehydration tank 2 refers to the range from the top of the dehydration tank 2 to 1/3 of the height of the dehydration tank 2, the center of the height of the dehydration tank 2 refers to the range from the top of the dehydration tank 2 to 1/3-2/3 of the height of the dehydration tank 2, and the lower part of the dehydration tank 2 refers to the range from the top of the dehydration tank 2 to below 2/3 of the height of the dehydration tank 2 (the range from the bottom of the dehydration tank 2 to 1/3 of the height of the dehydration tank 2). In other words, if the area from the top to the bottom of the dehydration tank 2 is divided into three ranges of the same height, it is divided into three ranges from the top of the dehydration tank 2: the upper part, the center of the height of the dehydration tank 2, and the lower part of the dehydration tank 2.

Figures 25(a) to 25(c) show the change in vibration of the upper end of the dehydration tub 2 when the rotation speed of the dehydration tub 2 is changed in various ways in one of the unbalanced states a, b, and c, respectively. The acceleration data (MX, MY, MZ) related to the left-right, up-down, and front-back directions detected by the acceleration sensor 56 attached to the outer peripheral surface 3a of the outer tub 3 is used to measure the vibration of the upper end of the dehydration tub 2.

As shown in Figures 25(a) to 25(c), in all of the unbalanced states a, b, and c, the change in the left-right and front-back vibrations of the upper end of the spin tub 2 is approximately the same, whereas the up-down vibrations of the upper end of the spin tub 2 change by a smaller value than the left-right and front-back vibrations.

In unbalanced state c, the magnitude of the vertical vibration of the upper end of the spin tub 2 is significantly smaller than the magnitude of the left-right and front-to-back vibrations, whereas in unbalanced state a and unbalanced state b, the magnitude of the vertical vibration of the upper end of the spin tub 2 is relatively close to the magnitude of the left-right and front-to-back vibrations.

That is, from FIG. 25, the coefficient A is calculated by (Equation 1) using the average value of the left-right acceleration MX and the front-back acceleration MZ, which are the acceleration data obtained in step SP22, as MXZ _ave and the up-down acceleration MY.
A = MXZ _ave / MY (Equation 1)

Therefore, if coefficient A is greater than 2 (A>2), it can be determined that the unbalanced state is c, and if coefficient A is less than 2 (A<2), it can be determined that the unbalanced state is a or b.

If there is no eccentricity in the dehydration tank 2, the dehydration tank 2 and the outer tank 3 rotate in sync, and the conditioned water is properly injected from the water injection nozzles 30a, 30b, and 30c into the water guide ducts 5a, 5b, and 5c. In contrast, if there is eccentricity in the dehydration tank 2, the dehydration tank 2 and the outer tank 3 do not rotate in sync, and the conditioned water is not properly injected from the water injection nozzles 30a, 30b, and 30c into the water guide ducts 5a, 5b, and 5c, resulting in the problem that the conditioned water from the water injection nozzles 30a, 30b, and 30c is injected into the wrong water guide ducts 5a, 5b, and 5c. In that case, it is not possible to properly control the dehydration tank 2 to eliminate the imbalance.

In particular, when the eccentric position in the dehydration tank 2 is at the top or center of the height of the dehydration tank 2, the vibration force at the top end of the dehydration tank 2 causes the upper end of the outer tank 3 to vibrate significantly, and the positional relationship between the water injection nozzles 30a, 30b, 30c of the nozzle unit 30 and the water guide buckets 5a, 5b, 5c is likely to change, which can easily cause problems with conditioned water from each water injection nozzle 30a, 30b, 30c being injected into the wrong water guide gutters 5a, 5b, 5c.

As shown in Figures 25(a) to 25(c), if the eccentric position in the dehydration tub 2 differs in the height direction, the vibration state of the dehydration tub 2 differs. Therefore, in this embodiment, the control method for the nozzle unit 30 is implemented taking into account the vibration state of the dehydration tub 2, i.e., the unbalanced state of the dehydration tub 2.

In this embodiment, the acceleration sensor 56 is a three-axis sensor that can detect acceleration in the left-right, up-down, and front-back directions. This makes it possible to accurately detect the amount of eccentricity (M) and the eccentricity position (N) even if the eccentricity position in the spin tub 2 varies in the height direction, as shown in Figures 25(a) to 25(c).

The washing machine 1 of this embodiment is arranged in an outer tub 3, a dehydration tub 2 with a pulsator 4 arranged at the bottom 2c, three baffles 8 that are arranged at equal intervals in the circumferential direction on the inner peripheral surface 2a of the dehydration tub 2 and that open near the bottom 2c and have a circulation water port 80 at the upper end, a water receiving ring unit 5 that is formed by stacking three annular water guide gutters 5a, 5b, and 5c that are respectively connected to the upper ends of the baffles 8 in the radial direction, a nozzle unit 30 that is fixed to the upper end of the dehydration tub 2 and can individually inject adjustment water into each of the water guide gutters 5a, 5b, and 5c, an acceleration sensor 56 that is an acceleration detection means for detecting vibrations of the outer tub 3, and a pulsator that detects the rotation of the dehydration tub 2 according to the rotation of the dehydration tub 2. The device is equipped with a proximity switch 55, which is a position detection device that transmits a pulse signal, an unbalance amount detection unit 65 and an unbalance position detection unit 66, which are eccentricity detection means that detect the amount of eccentricity and the eccentricity position in the spin tub 2, and a control unit 60, which is a control means that controls the nozzle unit 30 to inject water into the baffle 8 that corresponds to the eccentricity position when the amount of eccentricity reaches a predetermined eccentricity threshold (ma) during the spin watering process. The control unit 60 controls the nozzle unit 30 differently depending on whether the eccentricity position detected by the unbalance amount detection unit 65 and the unbalance position detection unit 66 is at the top or center in the height direction of the spin tub 2 or at the bottom of the spin tub 2.

According to the washing machine 1 of this embodiment, when the eccentric position in the dehydration tub 2 is at the top or center in the height direction of the dehydration tub 2, and when the eccentric position is at the bottom of the dehydration tub 2, there are possible operating states in which the positional relationship between the nozzles 30a, 30b, 30c of the nozzle unit 30 and the water guide tubs 5a, 5b, 5c is likely to change. However, by performing different controls according to the eccentric position in the dehydration tub 2, the positional relationship between the nozzles 30a, 30b, 30c and the water guide tubs 5a, 5b, 5c is prevented from changing. This prevents the adjustment water from the nozzle unit 30 from being poured into the wrong water guide tubs 5a, 5b, 5c, and allows appropriate control to be performed to eliminate the imbalance in the dehydration tub 2.

In the washing machine 1 of this embodiment, the control unit 60, which is a control means, starts controlling the nozzle unit 30 to inject water into the baffle 8, which is a water passage pipe section, during the spin-drying process, and then controls the nozzle unit 30 to stop injecting water into the baffle 8 when the amount of eccentricity detected by the imbalance amount detection unit 65 and the imbalance position detection unit 66, which are eccentricity detection means, becomes below a predetermined acceleration threshold (mc), and the second acceleration threshold (mc ₂ ) when the eccentric position is at the top or center in the vertical direction of the spin-drying tub 2 is smaller than the first acceleration threshold (mc ₁ ) when the eccentric position is at the bottom of the spin-drying tub 2.

According to the washing machine 1 of the present embodiment, when the rotation speed of the spin tub 2 in the spin cycle is lower than the resonant rotation speed and the eccentric position is located at the bottom of the spin tub 2, if the amount of water poured in is too large, the rotation speed of the spin tub 2 increases and becomes higher than the resonant rotation speed, and then the counter eccentric state may occur, causing increased vibration, but since the first acceleration threshold value (mc ₁ ) is set to a relatively large value, after the start of pouring water into the baffle 8, pouring water into the baffle 8 is stopped so that the pouring ends quickly before the amount of water poured becomes too large. This suppresses changes in the positional relationship between the nozzles 30a, 30b, 30c and the water guide buckets 5a, 5b, 5c, and prevents the adjusted water from the nozzle unit 30 from being poured into the wrong water guide gutters 5a, 5b, 5c.

In the washing machine 1 of this embodiment, when the rotation speed of the spin tub 2 is greater than the resonant rotation speed, the third eccentricity threshold (ma ₃ ) when the eccentric position is at the top or center in the vertical direction of the spin tub is smaller than the second eccentricity threshold (ma ₂ ) when the eccentric position is at the bottom of the spin tub 2.

According to the washing machine 1 of this embodiment, when the eccentric position is at the top or center in the height direction of the spin tub 2, the positional relationship between the nozzles 30a, 30b, 30c of the nozzle unit 30 and the water guide troughs 5a, 5b, 5c is likely to change, but because the third eccentricity threshold ( _ma3 ) is set relatively small, the water pouring process can be started at an early stage when the positional relationship between the nozzles 30a, 30b, 30c and the water guide troughs 5a, 5b, 5c is unlikely to change. This suppresses changes in the positional relationship between the nozzles 30a, 30b, 30c and the water guide troughs 5a, 5b, 5c, and prevents the conditioned water from the nozzle unit from being poured into the wrong water guide troughs 5a, 5b, 5c.

In the washing machine 1 of this embodiment, the control unit 60, which is a control means, controls the nozzle unit 30 to inject water into the baffle 8, which is the water passage pipe section corresponding to the eccentric position, only when the rotation speed of the dehydration tub 2 is equal to or lower than a predetermined upper limit rotation speed for pouring water (Na) during the spin-drying process, and the second upper limit rotation speed for pouring water (Na ₂ ) when the eccentric position is at the top or center in the vertical direction of the dehydration tub 2 is smaller than the first upper limit rotation speed for pouring water (Na ₁ ) when the eccentric position is at the bottom of the dehydration tub 2.

According to the washing machine 1 of this embodiment, if the eccentric position is at the top of the spin tub 2 or in the center in the height direction, when the rotation speed of the spin tub 2 increases and approaches the resonant rotation speed of the outer tub 3, the outer tub 3 resonates and vibrates greatly, which easily changes the positional relationship between the nozzles 30a, 30b, 30c and the water guide tubs 5a, 5b, 5c. However, since the upper limit rotation speed for water injection is set relatively small, water injection into the baffle 8 is stopped at a low stage when the rotation speed of the spin tub 2 does not approach the resonant rotation speed of the outer tub 3. This suppresses changes in the positional relationship between the nozzles 30a, 30b, 30c and the water guide tubs 5a, 5b, 5c, and prevents the conditioned water from the nozzle unit 30 from being injected into the wrong water guide tubs 5a, 5b, 5c.

In the washing machine 1 of this embodiment, when the water supply limit amount that can be poured into the baffle 8, which is the water passage pipe, changes depending on the rotation speed of the spin tub 2, the control unit 60, which is a control means, controls the nozzle unit 30 during the spin process so that the amount of water poured into the baffle 8 does not exceed the water supply limit amount according to the rotation speed of the spin tub 2.

In the washing machine 1 of this embodiment, during the spin-drying process, the nozzle unit 30 is controlled so that the amount of water poured into the baffle 8 does not exceed the water pouring limit amount according to the rotation speed of the spin-drying tub 2. This prevents the nozzle unit 30 from pouring more conditioning water than the water pouring limit amount, which would otherwise be wasted.

(Dehydration process)
A modified example of the control of the spin-drying process of the washing machine 1 of the present embodiment will be described below with reference to Fig. 26 and Fig. 27. Fig. 26 and Fig. 27 are flow charts showing the procedure of the modified example of the spin-drying process.

<Step SP101>

In step SP101, the central control unit 61 increases the rotation speed of the spin tub 2 and starts the spin-drying process.

<Step SP102>

In step SP102, the central control unit 61 determines whether the rotation speed of the spin tub 2 is 150 rpm or more. If the rotation speed is 150 rpm or more, the central control unit 61 proceeds to step SP103.

<Step SP103>

In step SP103, the central control unit 61 measures the amount of eccentricity (M) and the eccentricity position (N) of the spin tub 2. Then, the process proceeds to step SP104.

<Step SP104>

In step SP104, the central control unit 61 determines whether the amount of eccentricity (M) is equal to or greater than the eccentricity threshold (ma). If the amount of eccentricity (M) is greater than the eccentricity threshold (ma), the process proceeds to step SP105. If the amount of eccentricity (M) is less than the eccentricity threshold (ma), the process proceeds to step SP115. In step SP104, the first eccentricity threshold (ma ₁ ) is used as the eccentricity threshold (ma).

<Step SP105>

In step SP105, the central control unit 61 determines whether the eccentric position (N) is in the upper middle part of the spin tub 2 (eccentric position height determination). Specifically, the central control unit 61 determines whether the eccentric position (N) is in the upper part or the center in the height direction of the spin tub 2, or in the lower part of the spin tub 2. The method of determining the eccentric position height is the same as described above. If the eccentric position (N) is in the upper middle part of the spin tub 2, proceed to step SP106. If the eccentric position (N) is in the lower part of the spin tub 2, proceed to step SP107.

<Step SP106>

In step SP106, the central control unit 61 determines the acceleration threshold (mc) to be the second acceleration threshold (mc ₂ ), and then proceeds to step SP108.

<Step SP107>

In step SP107, the central control unit 61 determines the acceleration threshold (mc) to be the first acceleration threshold (mc ₁ ), and then proceeds to step SP108.

<Step SP108>

In step SP108, the central control unit 61 starts the water injection process. Then, it proceeds to step SP109.

<Step SP109>

In step SP109, the central control unit 61 determines the water injection limit amount for each rotation speed of the spin tub 2.

<Step SP110>

In step SP110, the central control unit 61 determines whether the amount of eccentricity (M) exceeds the acceleration threshold (mc). If the amount of eccentricity (M) exceeds the acceleration threshold (mc), the process proceeds to step SP111. If the amount of eccentricity (M) is below the acceleration threshold (mc), the process proceeds to step SP115. In step SP110, when the eccentricity position (N) is in the upper middle part of the spin tub 2, the second acceleration threshold ( _mc2 ) is used as the acceleration threshold (mc), and when the eccentricity position (N) is in the lower part of the spin tub 2, the first acceleration threshold ( _mc1 ) is used.

<Step SP111>

In step SP111, the central control unit 61 determines whether the amount of water poured is equal to or less than the water pouring limit amount. If the amount of water poured is equal to or less than the water pouring limit amount, the process proceeds to step SP112. If the amount of water poured is not equal to or less than the water pouring limit amount, the process proceeds to step SP113.

<Step SP112>

In step SP112, the central control unit 61 continues the water injection process and proceeds to step SP109.

<Step SP113>

In step SP113, the central control unit 61 judges whether the eccentricity amount (M) exceeds the acceleration threshold (mc). If the eccentricity amount (M) exceeds the acceleration threshold (mc), the process proceeds to step SP114. If the eccentricity amount (M) is below the acceleration threshold (mc), the process proceeds to step SP115. In step SP113, when the eccentricity position (N) is in the upper middle part of the spin tub 2, the fifth acceleration threshold ( _mc5 = _mc2 + _α2 ) which is greater than the second acceleration threshold ( _mc2 ) is used as the acceleration threshold (mc), and when the eccentricity position (N) is in the lower part of the spin tub 2, the first acceleration threshold ( _mc4 = _mc1 + _α1 ) is used. Note that _α1 and _α2 are positive numbers which are appropriately set.

<Step SP114>

In step SP114, the central control unit 61 stops the rotation of the spin tub 2 and ends the spin-drying process. Then, the process proceeds to step SP115.

<Step SP115>

In step SP115, the central control unit 61 increases the rotation speed of the spin tub 2 and proceeds to step SP116.

<Step SP116>

In step SP116, the central control unit 61 determines whether the rotation speed of the dehydration tub 2 is 300 rpm or more. If the rotation speed of the dehydration tub 2 is 300 rpm or more, the central control unit 61 proceeds to step SP117. If the rotation speed of the dehydration tub 2 is not 300 rpm or more, the central control unit 61 proceeds to step SP104.

<Step SP117>

In step SP117, the central control unit 61 determines the acceleration threshold (mc) to be the third acceleration threshold (mc ₃ ), and then proceeds to step SP118.

<Step SP118>

In step SP118, the central control unit 61 increases the rotation speed of the spin tub 2 and proceeds to step SP119.

<Step SP119>

In step SP119, the central control unit 61 determines whether the eccentric position (N) is in the upper middle part of the spin tub 2 (eccentric position height determination). If the eccentric position (N) is in the upper middle part of the spin tub 2, the process proceeds to step SP120. If the eccentric position (N) is in the lower part of the spin tub 2, the process proceeds to step SP122.

<Step SP120>

In step SP120, the central control unit 61 determines the upper limit rotation speed for water pouring (Na) to be the second upper limit rotation speed for water pouring (Na ₂ ), and proceeds to step SP121.

<Step SP121>

In step SP121, the central control unit 61 determines the third decentering amount threshold (ma ₃ ) as the decentering amount threshold (ma), and proceeds to step SP124.

<Step SP122>

In step SP122, the central control unit 61 determines the water pouring possible upper limit rotation speed (Na) to be the first water pouring possible upper limit rotation speed (Na ₁ ), and proceeds to step SP123.

<Step SP123>

In step SP123, the central control unit 61 determines the second eccentricity threshold (ma ₂ ) as the eccentricity threshold (ma), and proceeds to step SP124.

<Step SP124>

In step SP124, the central control unit 61 determines whether the rotation speed of the dehydration tub 2 is equal to or lower than the upper limit rotation speed (Na) at which water can be poured. If the rotation speed of the dehydration tub 2 is equal to or lower than the upper limit rotation speed (Na) at which water can be poured, water can be poured, and the process proceeds to step SP125. If the rotation speed of the dehydration tub 2 is higher than the upper limit rotation speed (Na) at which water can be poured, water cannot be poured, and the water pouring process is terminated. In step SP124, when the eccentric position (N) is in the upper middle part of the dehydration tub 2, the second upper limit rotation speed (Na ₂ ) at which water can be poured is used as the upper limit rotation speed at which water can be poured, and when the eccentric position (N) is in the lower part of the dehydration tub 2, the first upper limit rotation speed (Na ₁ ) at which water can be poured is used.

<Step SP125>

In step SP125, the central control unit 61 determines whether the eccentricity threshold (ma) is exceeded. If the eccentricity (M) exceeds the eccentricity threshold (ma), the process proceeds to step SP126. If the eccentricity (M) is below the eccentricity threshold (ma), the water injection process is terminated. In step SP125, when the eccentricity position (N) is in the upper middle part of the spin tub 2, the third eccentricity threshold (ma ₃ ) is used as the eccentricity threshold (ma), and when the eccentricity position (N) is in the lower part of the spin tub 2, the second eccentricity threshold (ma ₂ ) is used.

<Step SP126>

In step SP126, the central control unit 61 performs a water injection process while maintaining the rotation speed of the spin tub 2 without increasing it. Then, the process proceeds to step SP127.

<Step SP127>

In step SP127, the central control unit 61 determines whether the amount of eccentricity (M) exceeds the acceleration threshold (mc). If the amount of eccentricity (M) exceeds the acceleration threshold (mc), the process proceeds to step SP126 and the water injection process continues. If the amount of eccentricity (M) is below the acceleration threshold (mc), the water injection process ends. In step SP127, the third acceleration threshold (mc ₃ ) is used as the acceleration threshold (mc).

The above describes an embodiment of the present invention, but the configuration of this embodiment is not limited to the above, and various modifications are possible.

For example, in the above embodiment, the water receiving ring unit 5 is composed of three water guide gutters 5a, 5b, and 5c, and three baffles 8 are provided correspondingly, but this is not limited thereto, and any configuration may be used as long as three or more baffles 8 are provided and the same number of water guide gutters as the baffles 8 are provided.

In the above embodiment, when the rotation speed of the dehydration tank 2 is greater than the resonant rotation speed, the same acceleration threshold is set regardless of the eccentric position within the dehydration tank 2. However, when the rotation speed of the dehydration tank 2 is greater than the resonant rotation speed, different acceleration thresholds may be set when the eccentric position is at the top or center in the height direction of the dehydration tank 2 and when the eccentric position is at the bottom of the dehydration tank 2.

In the above embodiment, when the rotation speed of the dehydration tank 2 is lower than the resonant rotation speed, the same eccentricity threshold is set regardless of the eccentricity position within the dehydration tank 2. However, when the rotation speed of the dehydration tank 2 is lower than the resonant rotation speed, different eccentricity thresholds may be set depending on whether the eccentricity position is at the top or center in the height direction of the dehydration tank 2 or at the bottom of the dehydration tank 2.

In the above embodiment, when the rotation speed of the dehydration tub 2 is lower than the resonant rotation speed, the acceleration threshold when the eccentric position in the dehydration tub 2 is at the top of the dehydration tub 2 is the same as the acceleration threshold when the eccentric position is at the center of the height of the dehydration tub 2, but they may be different.

In the above embodiment, when the rotation speed of the dehydration tank 2 is greater than the resonant rotation speed, the eccentricity threshold when the eccentricity position in the dehydration tank 2 is at the top of the dehydration tank 2 is the same as the eccentricity threshold when the eccentricity position is at the center of the height of the dehydration tank 2, but they may be different.

In the above embodiment, the maximum rotation speed at which water can be poured is the same when the eccentric position in the dehydration tank 2 is at the top of the dehydration tank 2 as it is at the center of the height of the dehydration tank 2, but they may be different.

In the above embodiment, the water receiving plate 85 is disposed within the baffle 8, and the amount of water pouring is limited by the length and position of the water receiving plate 85, but this is not limited. The baffle 8 may be one in which the amount of water pouring is not limited.

In the above embodiment, the acceleration threshold, the upper limit rotation speed at which water can be poured, and the eccentricity threshold are different when the eccentricity position in the dehydration tank 2 is at the top or center in the height direction of the dehydration tank 2 and when it is at the bottom of the dehydration tank 2, but at least one of the acceleration threshold, the upper limit rotation speed at which water can be poured, and the eccentricity threshold may be different. In addition, thresholds other than the acceleration threshold, the upper limit rotation speed at which water can be poured, and the eccentricity threshold used when controlling water pouring by the nozzle unit may be different when the eccentricity position is at the top or center in the height direction of the dehydration tank and when it is at the bottom of the dehydration tank.

Other configurations can also be modified in various ways without departing from the spirit of the present invention.

1 Washing machine 2 Dehydration tub 2c Bottom of dehydration tub 3 Outer tub 4 Pulsator 5 Water receiving ring unit 5a, 5b, 5c Water guide pipe 8 Baffle (water passage pipe section)
30 Nozzle unit 55 Proximity switch (position detection device)
56 Acceleration sensor (acceleration detection means)
60 Control unit (control means)
65 Unbalance amount detection unit (eccentricity detection means)
66 Unbalanced position detector (eccentricity detector)
80 Circulating water outlet

Claims (4)

A dehydration tub is disposed in the outer tub and has a pulsator disposed at the bottom thereof;
three or more water passage pipes that are disposed at equal intervals in a circumferential direction on an inner peripheral surface of the dehydration tank, and that open near the bottom and have a circulating water port at an upper end;
a water receiving ring unit including three or more annular water guide gutters fixed to an upper end of the dewatering tub and connected to upper ends of the water passage pipes, the water receiving ring unit being radially stacked on top of each other;
A nozzle unit fixed to an upper end of the outer tank and capable of individually injecting conditioned water into each water guide pipe;
An acceleration detection means for detecting vibration of the outer tub;
a position detection device that transmits a pulse signal in response to rotation of the dehydration tub;
an eccentricity detection means for detecting an amount and position of eccentricity in the dehydration tub;
a control means for controlling the nozzle unit so as to inject water into the water passage pipe portion corresponding to the eccentric position when the eccentricity amount reaches a predetermined eccentricity amount threshold value in the dewatering process,
The nozzle unit has three or more water injection nozzles arranged above and outside each of the water guide ducts,
the control means controls the nozzle unit to stop injecting water into the water passage pipe section when the amount of eccentricity detected by the eccentricity detection means becomes equal to or less than a predetermined acceleration threshold value after starting control of the nozzle unit to inject water into the water passage pipe section during the dewatering process,
The washing machine, characterized in that the acceleration threshold when the eccentric position is at the top or center in the height direction of the dehydration tub is smaller than the acceleration threshold when the eccentric position is at the bottom of the dehydration tub . A dehydration tub is disposed in the outer tub and has a pulsator disposed at the bottom thereof;
three or more water passage pipes that are disposed at equal intervals in a circumferential direction on an inner peripheral surface of the dehydration tank, and that open near the bottom and have a circulating water port at an upper end;
a water receiving ring unit including three or more annular water guide gutters fixed to an upper end of the dewatering tub and connected to upper ends of the water passage pipes, the water receiving ring unit being radially stacked on top of each other;
A nozzle unit fixed to an upper end of the outer tank and capable of individually injecting conditioned water into each water guide pipe;
An acceleration detection means for detecting vibration of the outer tub;
a position detection device that transmits a pulse signal in response to rotation of the dehydration tub;
an eccentricity detection means for detecting an amount and position of eccentricity in the dehydration tub;
a control means for controlling the nozzle unit so as to inject water into the water passage pipe portion corresponding to the eccentric position when the eccentricity amount reaches a predetermined eccentricity amount threshold value in the dewatering process,
A washing machine characterized in that, when the rotation speed of the spin tub is greater than the resonant rotation speed, the eccentricity amount threshold when the eccentric position is at the top or center in the vertical direction of the spin tub is smaller than the eccentricity amount threshold when the eccentric position is at the bottom of the spin tub . A dehydration tub is disposed in the outer tub and has a pulsator disposed at the bottom thereof;
three or more water passage pipes that are disposed at equal intervals in a circumferential direction on an inner peripheral surface of the dehydration tank, and that open near the bottom and have a circulating water port at an upper end;
a water receiving ring unit including three or more annular water guide gutters fixed to an upper end of the dewatering tub and connected to upper ends of the water passage pipes, the water receiving ring unit being radially stacked on top of each other;
A nozzle unit fixed to an upper end of the outer tank and capable of individually injecting conditioned water into each water guide pipe;
An acceleration detection means for detecting vibration of the outer tub;
a position detection device that transmits a pulse signal in response to rotation of the dehydration tub;
an eccentricity detection means for detecting an amount and position of eccentricity in the dehydration tub;
a control means for controlling the nozzle unit so as to inject water into the water passage pipe portion corresponding to the eccentric position when the eccentricity amount reaches a predetermined eccentricity amount threshold in a dewatering process,
the control means controls the nozzle unit to inject water into the water passage pipe portion corresponding to the eccentric position only when the rotation speed of the dehydration tub is equal to or lower than a predetermined upper limit rotation speed at which water can be injected, during the dehydration process;
A washing machine characterized in that the upper limit rotation speed at which water can be poured when the eccentric position is at the top or center in the vertical direction of the dehydration tub is lower than the upper limit rotation speed at which water can be poured when the eccentric position is at the bottom of the dehydration tub . In a case where a water supply limit amount that can be supplied to the water supply pipe portion changes depending on a rotation speed of the dehydration tub,
The washing machine according to any one of claims 1 to 3, characterized in that the control means controls the nozzle unit during the dewatering process so that the amount of water poured into the water passage pipe does not exceed the water pouring limit amount corresponding to the rotation speed of the dewatering tub.

Images