JP2010051433A - Drum type washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain efficient low vibration dehydration by providing an acceleration sensor capable of detecting vibration in a plurality of directions and obtaining the magnitude relation of the amount of vibration in two directions in the predetermined number of rotations for dehydration so as to estimate the peak amount of vibration in a resonance area. <P>SOLUTION: This machine includes: a drum 11; a water tub 13 which includes the drum and in which washing water is stored; a motor 12 rotatively driving the drum; a vibration detection device 17 provided to the water tub 13 and detecting the amount of vibration in the plurality of directions; and an imbalance determination means 20 determining the amount of imbalance of laundry articles according to the output of the vibration detection device 17. The imbalance determination means 20 detects the magnitude relation of the amount of vibration in the respective directions in the predetermined number of rotations obtained from the vibration detection device 17 and when the difference between the amounts of vibration is larger than a predetermined value, switches a correction value to be applied to the amount of vibration obtained from the vibration detection device 17 to improve determination precision of the amount of vibration. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drum-type washing machine including a vibration detection device that detects vibrations in a plurality of directions of a water tank, obtained from the vibration detection device, and a magnitude relationship of vibration amounts between the respective axes at a predetermined number of rotations and vibration. The present invention relates to a drum-type washing machine that corrects the vibration amount obtained from the vibration detection device according to the magnitude of the amount difference and uses the corrected vibration amount to determine whether or not to shift to high-speed rotation. Is.

  In order to realize low vibration dehydration in the dehydration process of the drum type washing machine, it is premised that the vibration level during dehydration is accurately detected. The vibration level varies depending on the position of the water tub and the housing, and the vibration characteristics vary depending on the unbalanced state of the laundry. Therefore, finding an optimal vibration detection method has been a conventional problem.

  Many washing machines have been proposed so far, which determine the size of an imbalance based on the output result obtained from a vibration detection device provided in a water tub or housing and determine whether to shift to high-speed dewatering. Further, a washing machine has been proposed that specifies the position of the unbalance and realizes low vibration dewatering in addition to the determination of shifting the specified result to high speed dewatering.

  For example, a drum-type washing machine has been proposed in which the degree of unevenness of the clothing in the direction of the rotation axis is specified by two vibration detection devices attached to a water tank, and dehydration rotation control is performed based on the specification result (for example, a patent) Reference 1).

In addition, vibration detection means that can detect vibrations in multiple directions of two or more axes, identifies the unbalance position in the front-rear direction of the clothing from the difference in phase angle of each vibration component, and performs high-speed dehydration according to the unbalance position There has been proposed a drum-type washing machine that individually sets the reference value of the determination means that shifts to (see, for example, Patent Document 2).
Japanese Patent No. 3865791 JP 2006-311885 A

  However, since the conventional configuration (Patent Document 1) requires two vibration detection devices in order to specify the degree of bias, it is not desirable because it increases the cost of the equipment.

  Further, in the configuration of Patent Document 2, depending on how the laundry is biased, the maximum value detection timing of each vibration component is greatly shifted, making it difficult to obtain the phase angle difference, and specifying an accurate unbalanced position. I had a problem that I couldn't.

  Also, the unbalanced position is not simple, and there is a case where one side is biased toward the front side and the other side is biased toward the rear side. It had a problem that it could not be identified.

  The present invention solves the above-described conventional problems, and identifies the degree of unevenness of clothing that increases vibration from the magnitude of the difference in the resonance dehydration rotational speed, thereby realizing efficient imbalance determination. An object of the present invention is to provide a drum type washing machine with low vibration and low noise.

  In order to solve the above-described conventional problems, the present invention provides a drum having a water passage hole on the outer periphery, a water tank that contains the drum and stores washing water, a motor that rotationally drives the drum, and a housing that houses the water tank. A body, an anti-vibration damper that is attached between the water tank and the housing and suppresses vibration of the water tank, a vibration detection device that detects vibrations in a plurality of directions provided in the water tank, and an output of the vibration detection device And an unbalance determining means for determining an unbalance amount of the laundry, wherein the unbalance determining means detects a magnitude relationship between the vibration amounts in each direction at a predetermined rotational speed obtained from the vibration detecting device. When the vibration amount ratio in each direction is equal to or less than a predetermined value, the vibration amount obtained from the vibration detection device is corrected.

  As a result, it is possible to correct the vibration amount not only at the position where the vibration detection device is provided but also at the position where the vibration detection device is not attached with one vibration detection device. Thus, low vibration and low noise dehydration can be realized.

  The drum type washing machine of the present invention can accurately detect the amount of vibration at the time of dehydration with one vibration detection device, and can make an imbalance determination based on the result, thus reducing low vibration and low noise dehydration. Can be realized at a cost.

  According to a first aspect of the present invention, there is provided a drum having a water passage hole on an outer periphery thereof, a water tank that encloses the drum and stores washing water, a motor that rotationally drives the drum, a housing that houses the water tank, the water tank, An anti-vibration damper that is attached between the casings to suppress vibration of the water tank, a vibration detection device that detects vibration amounts in a plurality of directions provided in the water tank, and an unbalance of the laundry according to the output of the vibration detection device An unbalance determining means for determining an amount, wherein the unbalance determining means detects a magnitude relationship between the vibration amounts in each direction at a predetermined number of rotations obtained from the vibration detection device, and determines the vibration amount in each direction. By correcting the amount of vibration obtained from the vibration detection device when the ratio is equal to or less than a predetermined value, one vibration detection device can detect not only the position where the vibration detection device is provided, but also vibration. Detection equipment It is possible to correct the vibration amount of the position that is not attached, at low cost, to achieve an accurate vibration detection, low vibration, it is possible to realize a low noise dehydration.

  According to a second aspect of the present invention, the amount of vibration is a value in a first direction that is orthogonal to the rotation axis direction of the drum and is horizontal, and a second value that is orthogonal to the rotation axis direction of the drum and orthogonal to the first direction. By using the values of the two directions, it is possible to accurately estimate the maximum vibration amount generated at a position other than the position where the vibration detecting device is provided by comparing the vibration values in the two directions.

  According to a third aspect of the present invention, the correction value applied to the vibration amount obtained from the vibration detection device is larger as the magnitude relation of the vibration amount is larger in the first direction than the value in the second direction and the vibration amount ratio is smaller. As a result, the maximum amount of vibration generated outside the position where the vibration detection device is provided can be accurately estimated.

  According to a fourth aspect of the present invention, the predetermined rotational speed is from the rotational speed at which the vibration amount in each direction obtained from the vibration detection device starts to appear to the rotational speed before the resonance region where the vibration amount reaches a peak. It becomes possible to correct the vibration value in the resonance region where the value peaks during the dehydration process, thereby preventing abnormal vibration and improving the safety of the product.

  According to a fifth aspect of the invention, the imbalance determining means changes the dehydration rotation speed in accordance with the magnitude relationship between the vibration amounts in each direction and the magnitude of the vibration amount at the predetermined rotation speed obtained from the vibration detection device. By doing so, dehydration can be controlled based on the corrected maximum vibration amount, and low vibration and low noise dehydration can be realized.

  According to a sixth aspect of the present invention, the vibration detector is an acceleration sensor capable of detecting acceleration in three directions, wherein the first direction is orthogonal to the rotation axis direction of the drum and is in the horizontal direction, and the second direction is the drum. By making the direction orthogonal to the rotation axis direction of the first direction and the direction orthogonal to the first direction and the third direction as the rotation axis direction of the drum, vibrations in a plurality of directions can be detected by one sensor, Costs can be significantly reduced compared to providing sensors for each direction. In addition, it is possible to accurately determine the complicated movement of the water tank.

  According to a seventh aspect of the present invention, since the vibration detection device is provided at a substantially front portion in the rotation axis direction at the substantially upper portion of the outer periphery of the water tank, the device is provided at a position where the water tank is most likely to shake, and the sensitivity is improved even in a low speed region where the vibration is small. Good vibration detection can be performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 is a block diagram of a control device that suppresses vibration due to unbalance of the laundry of the drum type washing machine according to Embodiment 1 of the present invention. Moreover, FIG. 2 is a figure which shows the attachment position and vibration detection direction of the vibration detection apparatus in Embodiment 1 of this invention.

  In FIG. 1, 10 is a housing, 11 is a drum for storing and rotating laundry, and 12 is a motor for rotating the drum while controlling its speed. 13 is a water tank that encloses the drum 11 and stores water, 18 is a cover having a laundry inlet, 14 is a seal packing for connecting the water tank 13 and the cover 18 having the laundry inlet without a gap, 15 A support spring 16 for holding the posture of the water tank 13 is a vibration isolating damper for reducing vibration generated when the motor rotates to reduce vibration transmission to the housing 10 and the floor.

  Reference numeral 17 denotes a vibration detection device that detects the vibration of the water tank 13. As an example of the vibration detection device, an acceleration sensor capable of outputting a change in acceleration as a voltage change is used in the present embodiment.

  The acceleration sensor in the present embodiment uses a capacitance type acceleration sensor that converts a change in capacitance into a voltage. In addition, a piezoresistive acceleration sensor can be used. These so-called MEMS (Micro Electro Mechanical Systems) sensors are micro sensors fabricated using semiconductor integrated circuit fabrication technology, and in recent years, they have come to be mass-produced at low cost. It is used in equipment.

  The acceleration sensor according to the present embodiment employs a sensor capable of detecting three axes, detects vibrations in a plurality of directions, and accurately selects a vibration mode that changes complicatedly as the rotational speed increases during dehydration. It is possible to determine various unbalanced states. However, the acceleration sensor may be biaxial.

  In FIG. 2, the attachment position of the vibration detection device 17 and the vibration detection direction in the present embodiment are shown in detail.

The attachment position of the vibration detection device 17 is set to the upper part on the front side of the main body, which is farthest from the anti-vibration damper 16, and has good sensitivity especially at the time of minute shaking during low-speed dewatering rotation. Since the vibration when shifting to high-speed rotation with the unbalance of the laundry in the drum in the front part is larger than that in the rear part, high-speed rotation with a large unbalance in the front part It is necessary to avoid accelerating as much as possible. When the front part is unbalanced, the water tank shakes easily on the front side, so it is desirable that the vibration detector is attached to the front part.

  The vibration detection direction of the vibration detection device 17 is the X axis among the detection axes (the X axis, the Y axis, and the Z axis that are perpendicular to each other) of the triaxial acceleration sensor used in the present embodiment. The movement of the aquarium can be monitored in a three-dimensional manner by attaching the Y axis in a substantially front-rear (rotating axis) direction and the Z axis in a substantially vertical direction when viewed from the front of the main body in the horizontal direction.

  In the present embodiment, the X axis is the first vibration detection axis (first direction) and the Z axis is the second vibration detection axis (second direction).

  Reference numeral 19 denotes an anti-vibration rubber for installing the housing 10 on the floor, and the support spring 15 and the anti-vibration damper 16 constitute a support means. Further, 20 is an imbalance determination unit that determines imbalance according to the output of the vibration detection device, and 21 is a control unit that controls the rotation of the motor 12.

  FIG. 3 is a graph of a drum rotation control pattern in the first embodiment of the present invention. Immediately after the start of the dehydration process, the drum is repeatedly reversed at a rotational speed of 45 to 60 rpm to loosen the entanglements and lumps between the clothes, and the unwinding process is performed in order to make the clothes easily stick to the drum inner peripheral surface. Thereafter, at around 80 rpm at which clothing starts to cling to the inner peripheral surface of the drum, a preliminary unbalance determination is performed to determine a certain degree of unbalance in advance and temporarily stop dehydration (first unbalance determination section).

  When the vibration amount correction value determination section (120 rpm in this embodiment) before reaching the resonance region is reached, the motor is rotated at a constant speed to detect the vibration amount in the three directions. As the vibration amount, an output of the acceleration sensor (that is, acceleration), a result obtained by converting into a displacement amount from the relationship between the obtained acceleration and the rotational speed, or the like is used. In this embodiment, a displacement amount is used.

  The rotation speed of the vibration amount correction value determination section is optimally 120 rpm immediately before the resonance range, but if the rotation speed starts from the amount of vibration in each direction to the peak resonance range, it is not 120 rpm. May be. Further, the first unbalance determination section may not be 80 rpm as long as the number of rotations at which the clothing starts to stick to the inner peripheral surface of the drum.

  Based on the magnitude relationship between the detected vibration amounts in the three directions, whether the vibration amount correction is necessary in the resonance region (140 to 280 rpm) where the vibration amount reaches the peak, and how much correction is necessary based on the difference in the detected vibration amount. The determination is made in this section.

  When it is determined that correction is necessary, the above-described correction result is added to the vibration amount obtained from the acceleration sensor in the resonance region to determine whether to stop or continue (accelerate) dehydration.

  In this embodiment, after passing through the resonance region, a section (second unbalance determination section) for determining the unbalance amount based on the output value (vibration amount) of the vibration detection device is provided even at 300 rpm. It is also possible to correct the vibration amount based on the result of the presence or absence of the correction including the vibration amount detection in the subsequent steady dehydration rotation section (880 rpm in the present embodiment).

  FIG. 4 is a flowchart showing a series of processes for correcting the vibration amount and determining the unbalance based on the determination result of the vibration amount correction value.

  When the vibration amount correction value determination section (120 rpm) is reached after dehydration starts, the displacement in each of the three directions is determined in step 3 based on the output value for each axis of the triaxial acceleration sensor and the drum rotation frequency (f = 2 Hz). Calculate the amount. The displacement amount (X) can be calculated from the following equation.

X = a ÷ (2πf) ² [m]
a [m / s ² ]... acceleration, f [Hz]... rotational frequency Note that the Peak to Peak value of the displacement sampled for a predetermined time is defined as the vibration amount in this section. In the present embodiment, the acceleration sensor output is sampled at a sampling time of 10 msec, the PeaktoPeak value obtained by sampling every second is obtained, and the average value of the PeaktoPeak values of five consecutive times (5 seconds) is calculated as the vibration amount in this interval. It is said.

  The vibration amount used here is a displacement amount X1 [mm] in the first direction and a displacement amount X2 [mm] in the second direction. The value of the ratio A (= X2 / X1) of these X1 and X2 is calculated in advance.

  Next, in step 4, based on the calculated ratio A, it is determined whether or not amplitude correction in the resonance region is necessary. In the present embodiment, it is determined that correction is necessary if the ratio A is 0.3 or less, and otherwise unnecessary.

  Note that the smaller the ratio A is, the larger the correction value applied to the vibration amount is, and it is possible to accurately estimate the maximum vibration amount that occurs outside the position where the vibration detection device is provided.

  In step 7, the value obtained by correcting the maximum vibration amount in the resonance region obtained from the vibration detection device is set as the vibration amount used for determining whether to shift to high speed rotation. Comparison is made, and if the threshold value is exceeded, dehydration is stopped and retried.

  On the other hand, if it is determined that correction is not required, the maximum vibration amount in the resonance region obtained from the vibration detection device itself is determined as a vibration amount used for determining whether or not to shift to high speed rotation in step 11, and high speed rotation is performed in step 12. A comparison is made with the threshold value for determining whether or not the transfer is possible. If the threshold value is exceeded, dehydration is stopped and a retry is made.

  In the present embodiment, the maximum vibration amount in the resonance region is estimated based on the vibration amount correction value determined before reaching the resonance region, but the maximum vibration amount after passing through the resonance region can also be estimated. . Table 1 shows the amount of displacement (X1, X2) in the first direction and the second direction at 120 rpm and the ratio A (X2) using the same drum-type washing machine as in FIGS. / X1) is an example of the result of recording the maximum vibration amount at both the front and rear positions of the water tank in the resonance region (140 to 280 rpm).

  For verification, a pseudo load was used, and the amount of load and the position where it was affixed in the drum were changed so as to be able to cope with conditions that generate vibrations of various sizes and trends. Further, in order to measure the vibration amount on the rear side of the water tank, the same vibration detection device as that on the front side of the water tank is also provided on the upper rear side.

  Experiment No. 1 to 4 are the same amount of pseudo load in each experiment, affixed to the position (a) where the front side of the aquarium significantly swings, the position where the rear side swings (c), and the intermediate position (b). It is the result of having measured.

  As can be seen from the results, the ratio A decreases as it moves from the pasting position (a) to (c), while the value obtained by subtracting the rear vibration maximum value from the front vibration maximum value in the resonance region (difference B). The experiment no. In 1, 3 and 4, there was a negative vibration, that is, the rear vibration was larger than the front vibration. In this way, when the rear vibration is larger than the front, even if the vibration determination is simply performed with the vibration amount of the front, the large vibration of the rear is not reflected and the worst vibration may be overlooked. In the embodiment, it was confirmed that the vibration with the ratio A of 0.3 or less was determined as the vibration with the rear portion larger than the front portion, so that the oversight of the large rear portion vibration could be avoided.

  As described above, the vibration having the largest vibration at the position where the vibration detection device is not attached is also the magnitude relationship between the vibration amounts in a plurality of directions at a predetermined number of rotations obtained from the vibration detection device (that is, the vibration value X1 in this embodiment). The vibration amount is corrected when the vibration amount ratio (that is, the ratio A in the present embodiment) is equal to or less than a predetermined value. It was confirmed that the maximum amount of vibration could be determined.

As described above, the drum type washing machine according to the present invention detects the magnitude relationship between the vibration amounts in each direction at the predetermined number of rotations obtained from the vibration detection device, and the ratio of the vibration amounts in each direction is a predetermined value. The vibration amount is corrected at the following times, and the imbalance determination and dehydration rotation control can be performed based on the results. It is useful as a machine.

1 is a block diagram of a control device for a washing machine according to Embodiment 1 of the present invention. The figure which shows the attachment position and vibration detection direction of the 3-axis acceleration sensor which are the vibration detection apparatuses in Embodiment 1 of this invention. The graph which shows the drum rotation speed of the unbalance determination process in Embodiment 1 of this invention The flowchart showing a series of processing for correcting the vibration amount and determining the imbalance based on the determination result of the vibration amount correction value in the first embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Case 11 Drum 12 Motor 13 Water tank 14 Seal packing 15 Support spring 16 Anti-vibration damper 17 Vibration detector 18 Cover 19 Anti-vibration rubber 20 Unbalance determination means 21 Control means

Claims (7)

A drum provided with water passage holes on the outer periphery, a water tank that encloses the drum and stores washing water, a motor that rotationally drives the drum, a housing that houses the water tank, and a space between the water tank and the housing An anti-vibration damper that suppresses vibration of the water tank, a vibration detection device that detects vibration amounts in a plurality of directions provided in the water tank, and an unbalance that determines an unbalance amount of the laundry according to the output of the vibration detection device Determining means, wherein the unbalance determining means detects a magnitude relationship between vibration amounts in each direction at a predetermined rotational speed obtained from the vibration detection device, and a ratio of vibration amounts in each direction is equal to or less than a predetermined value. In this case, the drum type washing machine is adapted to correct the vibration amount obtained from the vibration detecting device. The amount of vibration uses a value in a first direction that is orthogonal to the rotation axis direction of the drum and in the horizontal direction, and a value in a second direction that is orthogonal to the rotation axis direction of the drum and orthogonal to the first direction. The drum type washing machine as set forth in claim 1. The correction value applied to the vibration amount obtained from the vibration detection device is increased as the magnitude relationship of the vibration amount is larger in the first direction than the value in the second direction and the vibration amount ratio is smaller. The drum type washing machine according to claim 2. The predetermined number of rotations is any one of claims 1 to 3 from a rotation number at which a vibration amount in each direction obtained from the vibration detection device starts to appear to a rotation number before a resonance region where the vibration amount reaches a peak. A drum-type washing machine as described in 1. The unbalance determination means changes the dehydration rotation speed in accordance with the magnitude relationship between the vibration amounts in each direction at the predetermined rotation speed obtained from the vibration detection device and the magnitude of the difference in vibration amount. The drum type washing machine of any one of -4. The vibration detection device is an acceleration sensor capable of detecting acceleration in three directions. The first direction is orthogonal to the drum rotation axis direction and the horizontal direction, and the second direction is orthogonal to the drum rotation axis direction. The drum-type washing machine according to any one of claims 1 to 5, wherein the direction is orthogonal to the first direction, and the third direction is a rotation axis direction of the drum. The drum type washing machine according to any one of claims 1 to 6, wherein the vibration detection device is provided at a substantially front portion in a rotation axis direction at a substantially upper portion of the outer periphery of the water tank.