Washing machine

Abstract

To provide a washing machine which can reduce vibration only in the condition that requires vibration suppression and which can shorten the time when vibration is large in conditions other than that.SOLUTION: A washing machine includes: a washing and dewatering tub for storing clothing; a water tub for including the washing and dewatering tub; a housing for storing the water tub; a drive mechanism for rotationally driving the washing and dewatering tub; a control device for controlling the drive mechanism and the like; a rotation speed sensor for measuring the rotation speed of the washing and dewatering tub; and a balancer provided inside the washing and dewatering tub. The control device includes: clothing amount estimation means for estimating a clothing amount; and a rotation pattern recording part in which the rotation pattern of the washing and dewatering tub is recorded. The rotation pattern includes time when the rotation speed of the washing and dewatering tub is kept at a fixed speed at the rotation speed higher than a resonance rotation speed. The control device includes vibration suppression control for lowering the rotation speed made to be constant for predetermined time, based on the estimation result of the clothing amount estimation means.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] The present invention relates to a washing machine having a laundry amount estimation means. [Background technology]

[0002] Washing machines are expected to have a large washing capacity, i.e., the amount of clothes they can wash at one time, and the washing capacity of models on the market is increasing year by year. However, there are limitations on the route to bring the washing machine in and the installation space, making it difficult to make the machine any larger, and so achieving a large capacity in a compact machine has become a challenge.

[0003] To achieve a compact, large-capacity washing machine, it is necessary to enlarge the washing / spin tub that holds the clothes. However, if the size of the main body is not changed, the gap between the housing and the water tub that contains the washing / spin tub will become smaller. This gap is provided to prevent the housing and water tub from coming into contact with each other and causing abnormal noise or damage even if vibrations occur due to unevenly distributed clothes during the spin cycle. Therefore, suppressing vibrations during spin cycle is important for a compact, large-capacity washing machine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-120014 Summary of the Invention [Problem to be solved by the invention]

[0005] Patent Document 1 proposes a method comprising an outer box, a water tank arranged inside the outer box and supported in a vibration-isolating manner by a vibration-isolating device, a drum arranged inside the water tank, a liquid-filled rotational balancer attached to the drum, a motor for rotating the drum, and control means for controlling the motor, and the control means reduces the angular acceleration of the drum in a rotational speed range above and below which includes the rotational speed range in which the water tank resonates.

[0006] However, although it is possible to reduce vibration displacement, there is a concern that the time spent operating at near the resonant rotation speed will become longer, that is, the time spent operating with large vibrations will become longer.

[0007] The present invention solves the above-mentioned conventional problems, and aims to provide a washing machine that reduces vibration only under conditions where vibration suppression is necessary, and can shorten the time during which vibration is high under other conditions. [Means for solving the problem]

[0008] In order to solve the above problems, the washing machine of the present invention comprises a washing and spin-drying tub for storing clothes, a water tub containing the washing and spin-drying tub, a housing for housing the water tub, a drive mechanism for rotating the washing and spin-drying tub, a control device for controlling the drive mechanism, etc., a rotational speed sensor for measuring the rotational speed of the washing and spin-drying tub, and a balancer provided inside the washing and spin-drying tub, wherein the control device comprises a clothes amount estimation means for estimating the amount of clothes and a rotational pattern recording unit for recording the rotational pattern of the washing and spin-drying tub, the rotational pattern having a time period during which the rotational speed of the washing and spin-drying tub is kept constant at a rotational speed higher than the resonant rotational speed, and the control device has vibration suppression control for lowering the rotational speed to be kept constant for a predetermined period of time based on the estimation result of the clothes amount estimation means. [Effects of the Invention]

[0009] According to the washing machine of the present invention, it is possible to provide a washing machine that suppresses vibration only under conditions where vibration suppression is necessary, and that can shorten the time during which vibration is large under other conditions. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a right side vertical cross-sectional view showing a washing machine according to a first embodiment. [Figure 2] FIG. 2 is a functional block diagram showing a control device of the washing machine. [Figure 3A] 10 is a graph showing an increase pattern of the rotation speed of the washing and spin-drying tub in relation to vibration suppression control in the first embodiment. [Figure 3B] 4 is a graph showing vibration displacement for each rotation pattern related to vibration suppression control in the first embodiment. [Figure 4] FIG. 2 is a schematic diagram showing the position of the water tub when clothes are loaded into the washing machine. [Figure 5] 10 is a table showing the amount of clothes to which vibration suppression control is applied in the first embodiment. [Figure 6] 10 is a table showing the amount of clothing to which the second vibration suppression control is applied in the first embodiment. [Figure 7] 10 is a table showing the amount of clothing to which the third vibration suppression control is applied in the first embodiment. [Figure 8A] 10 is a graph showing an increase pattern of the rotation speed of the washing and spin-drying tub in relation to vibration suppression control in the second embodiment. [Figure 8B] 10 is a graph showing vibration displacement for each rotation pattern related to vibration suppression control in the second embodiment. [Figure 9] 10 is a table showing the amount of clothing and the environmental temperature to which vibration suppression control according to the third embodiment is applied. DETAILED DESCRIPTION OF THE INVENTION

[0011] Example 1 <Washing machine S> 1 is a right-side vertical cross-sectional view showing a washing machine according to this embodiment. The washing machine S of the present invention is also applicable to a vertical washing machine that can also perform a drying process. The outer shell of the washing machine S is formed by an outer frame 1 of a housing that defines the outer shape. Inside outer frame 1 of the washing machine S are a water tub 2 that stores wash water, a washing and spin-drying tub 3 (inner tub) placed inside the water tub 2, rotors 4 (agitating blades) that rotate at the bottom of the washing and spin-drying tub 3, and a drive mechanism 10 (motor) that rotates rotors 4.

[0012] The outer frame 1 is formed into a rectangular parallelepiped shape elongated in the vertical direction by pressing a steel plate into a metal sheet or the like. A synthetic resin base 5 is provided at the bottom of the outer frame 1 as a bottom plate. A synthetic resin top cover 6 is provided above the outer frame 1. An operation and display panel 6a is provided on the front upper surface of the top cover 6 to enable the user to operate the washing machine S. The operation and display panel 6a is electrically connected to a control device 11 provided at the front lower part inside the washing machine S.

[0013] The water tank 2 is made of synthetic resin and has a generally cylindrical shape with a bottom. The water tank 2 is supported in the center of the outer frame 1 via a vibration isolation device 2b that engages with a locking portion 2a of the water tank 2.

[0014] Washing / spin-drying tub 3 has a cylindrical shape with a bottom and accommodates laundry (clothes) to be washed and spin-dried. Washing / spin-drying tub 3 is provided at the center inside water tub 2 and is supported rotatably relative to water tub 2, with its rotation axis z oriented in a substantially vertical direction.

[0015] The washing and spin-drying tub 3 has a large number of small through-holes 3a in its substantially cylindrical side wall for passing water and spin-drying. Note that Fig. 1 shows only some of the many small through-holes 3a, with the rest omitted. The washing and spin-drying tub 3 also has a plurality of through-holes 3b in its bottom wall for passing wash water and rinsing water. The upper edge of the washing and spin-drying tub 3 is also provided with an annular fluid balancer 3c (balancer).

[0016] Drive mechanism 10 is provided below water tub 2 and selectively drives rotor 4 and washing / spin-drying tub 3 to rotate via electromagnetic clutch 10a. Drive mechanism 10 uses, for example, a DC brushless motor driven by direct current. Drive mechanism 10 is controlled by vector control using control device 11. Drive mechanism 10 is provided with rotation speed sensor 10b, and control device 11 calculates the rotation speed based on the output of sensor 10b. Control device 11 is also provided with temperature sensor 11a (environmental temperature detection means) so that the temperature of the installation environment can be evaluated.

[0017] An outer lid 6b that can be freely opened and closed when a user puts laundry in or takes laundry out is provided on the top of the outer frame 1. The rear side of the outer lid 6b is pivotally supported by a top cover 6 provided on the top of the outer frame 1. In this way, laundry is put in or taken out of the washing / spin-drying tub 3 by opening and closing the outer lid 6b and through the laundry inlet 6c.

[0018] A water supply unit 7 that supplies wash water and rinse water is provided within the outer frame 1, behind the outer lid 6b of the top cover 6. The water supply unit 7 has a water supply box (not shown) with multiple water channels inside. The water supply unit 7 receives wash water and rinse water from a water supply hose connection port 8 that protrudes upward from the top cover 6. Specifically, tap water or bath water is supplied from the water supply hose connection port 8 and poured into the water tub 2. A detergent and finishing agent dispenser 6d is also provided behind the top cover 6. The detergent and finishing agent dispensed into the dispenser 6d are poured between the water tub 2 and the washing / spin tub 3 via a dispenser hose (not shown).

[0019] The rear side of the bottom of tub 2 is connected to wash water drain channel 2d for draining water via normally closed drain valve 2c, which opens when draining. Water is stored inside tub 2 by closing drain valve 2c during the wash and rinse cycles. When draining the wash water, drain valve 2c is opened, and the wash water and rinse water stored in tub 2 are discharged from wash water drain channel 2d to the outside of washing machine S (outside the machine).

[0020] Washing machine S is equipped with water level sensor 12 that detects the water levels of wash water and rinse water stored in water tub 2. An air trap 2e is provided near the bottom of water tub 2, and air tube 13 is connected to and communicates with air trap 2e, and water level sensor 12 is connected to the upper end of air tube 13.

[0021] <control block> FIG. 2 is a block diagram showing the control of the washing machine S of this embodiment. The control device 11 of the washing machine S is composed of an operation control unit 200, a rotation speed calculation unit 201, a clothes amount estimation unit 202, a rotation pattern recording unit 203, and a rotation pattern selection unit 204, and controls the washing machine S based on information input to the operation / display panel 6a. The operation / display panel 6a is a means for inputting settings such as washing courses, washing time, and the number of rinses. During operation, the rotation speed of the drive mechanism 10 (drive motor) is detected by a rotation speed sensor 10b, and the rotation speed is calculated by a rotation speed calculation unit 201 in the control device 11. When operation begins, the operation control unit 200 drives the drive mechanism 10, and the clothes amount estimation unit 202 estimates the amount of clothes placed in the washing / spin tub 3 based on the rotation speed of the drive mechanism 10 at that time and the current required for driving. The control device 11 determines the amount of water to be supplied, etc., based on the estimated clothes amount. Water supply and drainage are controlled by controlling the water supply valve 17 on the water supply unit 7 and the drain valve 2c on the bottom of the water tub 2. During water supply, the amount of water poured is controlled by detecting the water level with the water level sensor 12. During the wash cycle, the operation control unit 200 adjusts the wash time and other settings based on the results measured by the temperature sensor 11a, enabling washing performance that is less dependent on the ambient temperature. During the spin cycle, the rotation of the drive mechanism 10 is controlled based on the rotation pattern of the washing and spin-drying tub 3 stored in the operation control unit 200. In this invention, vibration is reduced by changing the rotation pattern of the washing and spin-drying tub 3 based on the laundry load. Based on the results of the laundry load estimation unit 202, the rotation pattern selection unit 204 selects from the rotation patterns stored in the rotation pattern recording unit 203 a rotation pattern that can suppress vibration or shorten the period of high vibration.

[0022] <Vibration suppression control> It is generally known that the higher the rate of increase in rotational speed when passing through resonance, the lower the maximum vibration displacement. On the other hand, in devices with a fluid balancer, such as washing machines, the higher the rate of increase in rotational speed, the larger the maximum vibration displacement. A fluid balancer is constructed by sealing a liquid (balancer liquid) such as water inside a ring, which causes the balancer liquid to shift in the direction of the vibration displacement. When a rotor vibrates at rotational speeds lower than resonance, it vibrates in the direction of the excitation force. As it approaches resonance, the direction of the excitation force and the vibration shift, and at rotational speeds sufficiently higher than resonance, it vibrates in the opposite direction to the excitation force. Therefore, the direction of the balancer liquid shift and the direction of the excitation force are opposite, resulting in a decrease in vibration. When the acceleration rate of the washing / spinning tub 3 is low, the balancer liquid can follow the shift in the vibration direction related to resonance. However, at high acceleration rates, the balancer liquid movement cannot follow the change in vibration direction, which is thought to increase vibration.

[0023] Therefore, instead of continuing to accelerate after passing through resonance, a period of time is provided in which the rotation speed is maintained at a speed close to the resonance rotation speed, ensuring that the balancer liquid has time to catch up with the rotation of the washing and spin tub, thereby suppressing vibration.

[0024] FIG. 3A shows the rotational speed increase pattern in this embodiment, and FIG. 3B shows the relationship between time and vibration displacement for each rotational pattern. As shown in FIG. 3A, in normal control, the rotational speed continues to increase after passing the resonant rotational speed until the vibration displacement decreases, and then the rotational speed remains constant. On the other hand, in vibration suppression control, the rotational speed at which the rotational speed remains constant (the rotational speed that remains constant for a predetermined time) after passing the resonant rotational speed is lowered compared to normal control. Specifically, it is lowered by approximately 20 to 50 min-1. As shown in the vibration displacement shown in FIG. 3B, in normal control, the vibration displacement increases sharply due to resonance, then decreases to a predetermined displacement and remains approximately constant. In contrast, when vibration suppression control is applied, the vibration begins to decrease when acceleration is stopped, resulting in a lower maximum vibration displacement compared to normal control. However, because constant rotation is performed at the resonant rotational speed compared to normal control, the rate at which the vibration displacement decreases is slower, and it takes longer for the vibration displacement to become approximately constant.

[0025] As described above, vibration suppression control can reduce the maximum vibration displacement, but the vibration remains high for a long time until it becomes approximately constant. Therefore, when the laundry load is smaller or larger than a predetermined amount, the vibration space is small and the maximum displacement must be suppressed, so vibration suppression control is applied. On the other hand, when the laundry load is intermediate and there is sufficient vibration space, the rotation speed that becomes constant after passing the resonant rotation speed can be set high, thereby preventing contact between the outer frame 1 (housing) and the water tub 2 and shortening the time when the vibration is high.

[0026] 3B, vibration suppression control can reduce the maximum displacement but has the disadvantage of causing a long period of high vibration, while normal control can shorten the period of high vibration and reduce the user's discomfort but has the disadvantage of causing a large maximum displacement. Therefore, the spin control that takes clothing load into consideration in the present invention uses vibration suppression control only under conditions that require vibration suppression, and uses normal control under other conditions to reduce the user's discomfort.

[0027] Figure 4 shows the relationship between the amount of laundry and the position of the water tub 2. The left side of Figure 4 shows a small amount of laundry (small load), the right side shows a large amount of laundry (large load), and the center side shows a load between a large and small load (medium load, a range where the amount of laundry is intermediate). A gap, indicated by the double arrow in Figure 4, is provided between the outer frame 1 and the water tub 2 to prevent the water tub 2 from contacting the outer frame 1 even when it vibrates during the spin cycle. Furthermore, the water tub 2 is typically suspended from the outer frame 1 via a spring, and moves downward when water or clothes are added to the water tub 2 or the washing / spinning tub 3. Therefore, the vertical gap between the outer frame 1 and the water tub 2 changes depending on the amount of laundry added to the washing / spinning tub 3. As shown in the left side of Figure 4, when the load is small, the water tub 2 is positioned higher, resulting in a small gap at the top and a large gap at the bottom. As shown in the center side of Figure 4, when the load is medium, the water tub 2 moves downward, increasing the gap at the top, resulting in sufficient gaps at both the top and bottom. When the load increases further and reaches the heavy load state shown in the right diagram of Figure 4, the gap at the bottom decreases and a large gap appears at the top. As such, under light and heavy loads, the gap at either the top or bottom becomes smaller, so there is a concern that small vibration displacements may cause contact between the outer frame 1 and the water tank 2, and therefore vibration needs to be suppressed more than under intermediate loads.

[0028] Therefore, as shown in the table in Figure 5, vibration suppression control is applied at low and high loads when the gap between the housing (outer frame 1) and the water tank 2 becomes small, and normal control that prioritizes reducing user discomfort is applied at medium loads when sufficient gap can be secured. This suppresses vibration only under necessary conditions, and reduces user discomfort by shortening the time when vibration is high under other conditions.

[0029] In this embodiment, the amount of laundry is divided into three stages (three ranges) and vibration suppression control is applied when the amount of laundry is a light load and a heavy load, but it is not necessary to divide it into three stages, and control can also be divided into two stages.

[0030] For example, as shown in Figure 6, the load can be divided into two stages (two ranges): a standard load of 20% or more of the rated capacity, and a small load of less than 20%, and vibration suppression control is applied only to the small load with a small upper clearance. During spin-drying, the water tub 2 sinks compared to when the washing and spin-drying tub 3 is empty due to the weight of wet clothes, but during washing, the water tub 2 also sinks due to the wash water, so it moves lower than during spin-drying. Therefore, if the amount of sinking during washing is taken into account and the downward movement is set large, there will be sufficient clearance for downward vibration even under large loads, and vibration suppression control only needs to be applied to small loads. By using standard control for large loads, the time when vibration is high can be shortened, reducing user discomfort.

[0031] Furthermore, as shown in Figure 7, it is also possible to divide the load into two stages (two ranges), with a standard load of less than 80% of the rated capacity and a heavy load of 80% or more. In the case of a top-load washing machine, vertical vibrations tend to increase when the clothes are unevenly distributed at the top and bottom in opposite circumferential positions. When a large amount of clothes is loaded, the clothes may be loaded all the way to the top of the washing / spinning tub 3, causing uneven distribution at the top. On the other hand, when the load is small, less than 20% of the rated capacity, the clothes are only located at the bottom of the washing / spinning tub 3, so uneven distribution at the top does not occur. Therefore, it is possible to apply vibration suppression control only to heavy loads, which tend to reduce the gap at the bottom, assuming that vertical vibrations are unlikely to increase at light loads. In this way, standard control can be used at light loads to shorten the time when vibrations are high, thereby reducing user discomfort.

[0032] Although the present embodiment is described taking a vertical washing machine as an example, the same applies to a drum washing machine.

[0033] Example 2 Vibration suppression control different from that of Example 1 will be described using Figures 8A and 8B. Note that since the structure is the same as that of Example 1 and only the control is different, a description of the points in common with Example 1 will be omitted. Figure 8A shows a rotation speed control method for suppressing vibration in this example, and Figure 8B shows the relationship between time and vibration displacement for each rotation pattern. In the vibration suppression control of Example 1, the acceleration rate when passing through resonance is set to be the same as that of normal control (see Figure 3A), but in this example shown in Figure 8A, the acceleration rate in the resonance region of vibration suppression control is set smaller than that of normal control. By passing through resonance over time, the balancer liquid can follow the acceleration rate of the water tank, and the maximum value of vibration displacement can be reduced (see Figure 8B).

[0034] Example 3 Using FIG. 9, a vibration suppression control different from that of the first embodiment will be described. Since the structure is the same as that of the first embodiment and only the control is different, a description of the commonalities with the first embodiment will be omitted. FIG. 9 shows the conditions under which the vibration suppression control of this embodiment is applied in a table. It is generally known that the damping performance of a vibration-proof structure decreases as the temperature increases. For example, in the case of an oil damper, the damping force decreases as the viscosity of the oil decreases. When the damping performance of the vibration-proof structure decreases, vibration increases more than usual even for the same amount of clothing misalignment, and the allowable amount of misalignment (allowable imbalance) decreases. The smaller the allowable imbalance, the more likely it is that spin start will need to be restarted, raising concerns about extended operation time. Therefore, it is desirable to suppress vibration under high-temperature conditions where damping performance decreases. Therefore, to suppress the deterioration of spin start performance due to ambient temperature, a control method that takes both the amount of clothing and the ambient temperature into account, as shown in FIG. 9, is available. When the ambient temperature (measurement result) detected by the temperature sensor 11a is 30°C or below, vibration suppression is possible without a significant decrease in damping performance compared to that at 20°C. As in the first embodiment, vibration suppression control is used when the amount of clothing is less than 20% and more than 80%. On the other hand, when the ambient temperature is 30°C or higher (predetermined temperature, high temperature), vibration displacement increases due to a decrease in damping performance, and if the gap between the outer frame 1 and the water tank 2 remains unchanged, the allowable amount of imbalance decreases, making dehydration more likely to fail. To prevent this, vibration suppression is necessary, so the application range of vibration suppression control is expanded compared to when the temperature is low, to less than 40% and more than 60%. This reduces the probability of having to restart the dehydration even in a high-temperature environment, and makes it possible to prevent the operation time from being extended.

[0035] In this embodiment, the conditions for applying vibration suppression control are determined by a combination of the amount of clothing and the ambient temperature, but the ambient temperature alone may also be used as the judgment criterion, and vibration suppression control may be applied when the ambient temperature is higher than a predetermined temperature. [Explanation of symbols]

[0036] 1 Outer frame (casing) 2. Aquarium 3 Washing and spinning tub 3c Fluid balancer (balancer) 10b Rotational speed sensor 11 Control device 11a Temperature sensor (environmental temperature detection means) 200 Operation control unit 201 Rotational speed calculation unit 202 Clothing quantity estimation method 203 Rotation pattern recording unit 204 Rotation pattern selection section

Claims

1. The washing machine comprises a washing and spin-drying tub for accommodating clothes, a water tub containing the washing and spin-drying tub, a housing for accommodating the water tub, a drive mechanism for driving the washing and spin-drying tub to rotate, a control device for controlling the drive mechanism, a rotation speed sensor for measuring the rotation speed of the washing and spin-drying tub, and a balancer provided inside the washing and spin-drying tub, the control device has a clothes amount estimation means for estimating the clothes amount and a rotation pattern recording unit for recording a rotation pattern of the washing and spin-drying tub, the rotation pattern having a time period during which the rotation speed of the washing and spin-drying tub is kept constant at a rotation speed higher than the resonance rotation speed; The control device has a vibration suppression control that reduces the rotation speed to be constant for a predetermined time based on the estimation result of the laundry amount estimation means.

2. The washing machine according to claim 1, The control device divides the amount of laundry into at least two ranges based on the estimation result of the laundry amount estimation means, and uses the vibration suppression control when the amount of laundry is small compared to when the amount of laundry is large.

3. The washing machine according to claim 1, The laundry amount estimating means divides the laundry amount into at least two ranges, and applies the vibration suppression control when the laundry amount is large compared to when the laundry amount is small.

4. The washing machine according to claim 1, The laundry amount estimation means divides the laundry amount into at least three ranges, and applies the vibration suppression control when the laundry amount is small or large in the middle range.

5. The washing machine comprises a washing and spin-drying tub for accommodating clothes, a water tub containing the washing and spin-drying tub, a housing for accommodating the water tub, a drive mechanism for driving the washing and spin-drying tub to rotate, a control device for controlling the drive mechanism, a rotation speed sensor for measuring the rotation speed of the washing and spin-drying tub, and a balancer provided inside the washing and spin-drying tub, The control device has a clothes amount estimation means for estimating the clothes amount and a rotation pattern recording unit for recording the rotation pattern of the washing and spin-drying tub, The washing machine is characterized in that the control device has vibration suppression control that reduces the acceleration rate in the resonance region based on the estimation result of the laundry amount estimation means.

6. The washing machine comprises a washing and spin-drying tub for accommodating clothes, a water tub containing the washing and spin-drying tub, a housing for accommodating the water tub, a drive mechanism for driving the washing and spin-drying tub to rotate, a control device for controlling the drive mechanism, a rotation speed sensor for measuring the rotation speed of the washing and spin-drying tub, and a balancer provided inside the washing and spin-drying tub, the control device has a rotation pattern recording unit that records a rotation pattern of the washing and spin-drying tub, the rotation pattern having a time period during which the rotation speed of the washing and spin-drying tub is kept constant at a rotation speed higher than a resonance rotation speed; The control device is characterized in that, based on the measurement results of the environmental temperature detection means, when the temperature is higher than a predetermined temperature, the conditions for applying vibration suppression control that reduces the rotation speed to keep it constant for a predetermined time are expanded compared to when the temperature is lower.

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