JP2006081637A - Washing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently detect the abnormal vibrations of the dehydrator showing different vibration modes depending on the number of revolutions in a washing machine. <P>SOLUTION: The vibrations of the dehydration tub 108 of the washing machine 101 are detected with a three-dimensional acceleration sensor 117 mounted on the outer tub 105. The acceleration sensor 117 produces the Z-axis side output as the detection signal of the acceleration in the direction of the rotating shaft of the washing/dehydration tub 108, the X-axis side output as the detection signal of the acceleration in the direction orthogonal to the direction of the rotating shaft of the washing/dehydration tub 108 and the Y-axis side output as the detection signal of the acceleration containing the rotation-wise components of the washing/dehydration tub 108 vertical to the direction of the rotating shaft of the washing/dehydration tub 108 while being orthogonal to the X axis. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an invention for detecting abnormal vibration during dehydration, particularly in a washing machine with a dehydrating function that can dehydrate washed clothes and the like.

  In a dehydrator that dehydrates laundry by centrifugal force following the rotation of the dehydration tank, if there is uneven distribution of the laundry in the dehydration tank or the weight distribution of the laundry in the dehydration tank, abnormal vibration will occur in the dehydration tank during dehydration. May occur.

  This abnormal vibration causes inconveniences such as generation of noise, movement of the washing machine, and failure of the washing machine. Therefore, a configuration is proposed in which it is detected at an early stage and control is performed such as reducing the rotation speed of the dewatering tank. Has been. These techniques are described in Patent Documents 1 to 3, for example.

Japanese Patent Laid-Open No. 06-282 Japanese Patent Laid-Open No. 11-169581 JP 2003-71180 A

  The vibration of the dehydration tank is not the same as the vibration at the time of low-speed rotation at the start of rotation and the vibration at a stage when a certain amount of time has elapsed from the start of rotation. Therefore, an optimum vibration detecting means corresponding to the state of vibration is required. That is, since the vibration mode differs depending on the rotation speed of the dehydration tank, a vibration detection technique suitable for the vibration mode is required.

  Moreover, if the detection of abnormal vibrations in the dewatering tank is too sensitive, it becomes a washing machine in which the dewatering operation is frequently stopped, which is not preferable because of poor usability. On the other hand, if the ability to detect abnormal vibration is low, abnormal noise and a decrease in product life due to abnormal vibration are likely to occur, which is also not preferable. In this regard, in the conventional technique, since vibration corresponding to the vibration mode of the dewatering tank is not detected, vibration of the dewatering tank cannot be detected effectively.

  An object of this invention is to provide the technique which detects the abnormal vibration in a dehydration apparatus which shows the vibration mode which changes with rotation speed effectively.

The present invention
In a washing machine with a dehydrating function equipped with an acceleration sensor for detecting acceleration,
At least a dehydration tank for dehydration;
First acceleration detection means for detecting vibration in a direction perpendicular to the rotation axis of the dehydration tank;
Second acceleration detection means for detecting vibration in the direction of the rotation axis of the dehydration tank;
Third acceleration detection means for detecting vibration in a direction orthogonal to the vibration direction detected by the first acceleration detection means and orthogonal to the vibration direction detected by the second acceleration detection means;
Have
According to the detection signal of the third acceleration detection means, the signal from the first acceleration detection means and the signal from the second acceleration detection means are switched to detect the vibration of the dehydration tank.
Also,
The third acceleration detection means is an acceleration detection means for detecting vibrations in the rotation direction of the dehydration tank, and detects vibrations orthogonal to the vibration direction detected by the second acceleration detection means.
further,
The first acceleration detection means, the second acceleration detection means, and the third acceleration detection means are constituted by an integrated three-axis acceleration sensor.
Also,
A noise filter is provided in the detection path of the third acceleration detecting means.

  The present invention provides, for example, dehydration that vibrates with anisotropy such that the vibration mode in the vibration mode in the direction orthogonal to the rotation axis of the dehydration tank (horizontal direction) and the vibration mode in the rotation axis direction of the dehydration tank (vertical direction) differ It is applied to a mechanism that detects the vibration of a washing machine with functions. According to the present invention, since optimum processing corresponding to different vibration modes can be performed on the output of the acceleration sensor (acceleration detection output) for detecting each vibration mode, vibration is effectively detected. be able to. Furthermore, in order to switch the output of the acceleration sensor in the two directions, the switching is performed by the third acceleration detecting means that is orthogonal to the horizontal direction and also orthogonal to the vertical direction. It becomes possible to output.

  For example, consider a case where a cylindrical object is rotated about the axis of the cylinder. In this case, the cylinder vibrates during rotation due to weight imbalance, bearing backlash, and the like. At this time, the vibration mode in the axial direction of the cylinder is different from the vibration mode in the direction orthogonal to the axis. Here, the vibration mode refers to the state of vibration or the type of vibration.

  In order to detect the vibration of the cylinder, for example, an acceleration sensor may be fixed to the bearing, and the change in acceleration in the axial direction and the change in acceleration in the direction orthogonal to the axial direction may be detected. Since the modes are different, the output of the acceleration sensor in the two directions is a different form of signal. In the present invention, processing suitable for the different vibration modes is added to the output of the acceleration sensor that detects vibrations of different modes, thereby increasing the vibration detection efficiency. Furthermore, in order to switch the output of the acceleration sensor in the two directions, the output of the third acceleration detection means resulting from the rotation direction of the cylinder is used, so that it is not necessary to separately provide a rotational speed detection means such as an encoder. It is possible to perform accurate detection using only the acceleration sensor.

  Further, by forming the first acceleration detecting means and the second acceleration detecting means, which are acceleration sensors in two directions, and the third acceleration detecting means for switching between them, the number of parts can be reduced. It becomes possible, and the cost can be reduced.

  When the dewatering tank rotates, a vibration mode in the rotation axis direction and a vibration mode in a direction orthogonal to the rotation axis appear. For example, a general dewatering tank arranged in a vertical shape rotates with a motion such that the upper part of the dewatering tank swings its head at the start of rotation with a relatively long slow cycle. This motion of shaking the head is periodic and a kind of vibration. This vibration mode is detected as vibration characterized by the amplitude in the horizontal direction (that is, the direction orthogonal to the rotation axis). For convenience, this vibration is referred to as lateral vibration.

  As the rotational speed increases, the rotational moment increases, so that the movement of shaking the head is reduced, and instead, a vibration mode in which the entire dehydration tank vibrates in small increments appears. This vibration mode is detected as vibration characterized by the amplitude in the direction of the rotation axis of the dehydration tank. For convenience, this vibration is referred to as longitudinal vibration.

  Lateral vibration is vibration that appears when the dewatering tank is rotating at a low speed. However, since the cycle is long, the acceleration is not so large, and therefore the output of the acceleration sensor that detects the lateral vibration has a relatively small value. On the other hand, the longitudinal vibration is a vibration that appears when the dehydration tank is rotating at high speed, so the amplitude is relatively small but the acceleration accompanying the vibration is large, and the output from the acceleration sensor is a relatively large value. It becomes.

  As described above, in the aspect in which the present invention is applied to the dewatering tub of the washing machine, the vibration mechanism of the lateral vibration and the vertical vibration is different. Therefore, in order to accurately detect the vibration of the dewatering tub, an acceleration sensor that detects the lateral vibration is used. It is important to separate the handling of the output from the handling of the output of the acceleration sensor that detects longitudinal vibration.

  In the above-described aspect, the process for the output of the first acceleration detecting means for detecting the lateral vibration and the process for the output of the second acceleration detecting means for detecting the longitudinal vibration can be made suitable for the form of each signal. For this reason, the vibration of the dewatering tank can be accurately detected, and the safety device can be effectively controlled by detecting the abnormal vibration of the dewatering tank.

  In addition, since a noise filter is provided in the detection path of the third acceleration detection means, it is possible to prevent the commercial power supply frequency of the motor for rotating the dehydration tank from being mixed in the sensor output, and to ensure the dehydration tank It becomes possible to detect the vibration accompanying the rotation of.

  It should be noted that the axial direction of the dehydrating tank detected by the second acceleration detecting means only needs to coincide with the axial direction to the extent that vibration in the rotating axis direction of the dehydrating tank can be detected.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which detects the abnormal vibration in the dehydration apparatus which shows the vibration mode which changes with rotation speed effectively is provided.

  Hereinafter, the example at the time of applying the vibration detection mechanism of this invention to the 1 tank type washing machine is demonstrated.

  FIG. 1 is a sectional view showing an example of a sectional structure of a washing machine. FIG. 1 shows a state in which the washing machine 101 includes legs 103 and is arranged on a suitable base 104. The washing machine shown in FIG. 1 has a function of performing washing and subsequent dehydration using the washing tub / dehydration tub 108.

  A washing machine 101 shown in FIG. 1 includes a washing tub / dehydration tub 108 in which an outer tub 105 and a laundry 114 are placed in an outer structure 102. The outer tub 105 has a structure suspended from the outer structure 102 in the outer structure 102 by a suspension member 106. A spring 107 is disposed between the suspension member 106 and the outer tub 105, and the outer tub 105 is elastically suspended in and supported by the outer structure 102.

  A motor 111 is attached to the outer tub 105, and a rotating shaft 112 of the motor 111 is supported by a bearing 113 so that rotational driving force can be transmitted to the washing tub / dehydrating tub 108 and the stirring blade 109. The motor 111 is a motor that performs an operation in which the rotational speed increases to the maximum rotational speed when energization is started.

  At the time of washing (for example, washing with a detergent) or rinsing, the driving force of the motor 111 is not transmitted to the washing tub / dehydration tub 108, but the driving force is transmitted to the stirring blade 109 and is put in the washing tub / dehydration tub 108. The laundry and the poured water are agitated.

  At the time of dehydration, the stirring blade 109 is fixed to the washing tub / dehydration tub 108, and the washing tub / dehydration tub 108 is driven by a motor 111 to rotate relative to the outer structure 102. The mechanism for switching the drive from the motor 111 is provided on the rotating shaft 112 although details are not shown.

  In addition, a flexible hose 116 is connected to the outer tank 105 via a drain valve 115, and an acceleration sensor 117 for detecting vibration of the outer tank 105 is attached.

  Although the acceleration sensor 117 is a single element as will be described later, it has a function of individually detecting acceleration in a three-dimensional direction. Here, a detection signal of acceleration (acceleration in the Z-axis direction) from the acceleration sensor 117 in the rotation axis direction of the washing tub / dehydration tub 108 (the axial direction of the rotation axis 112 of the motor 111, hereinafter referred to as the Z axis) is orthogonal to the detection signal. Detection signal of acceleration (acceleration in the X-axis direction) in the axial direction (horizontal direction, hereinafter referred to as X-axis) and acceleration (Y-axis direction) in the axial direction (rotation direction, hereinafter referred to as Y-axis) orthogonal to the X-axis and Z-axis (Acceleration) detection signal.

  Next, an example of a vibration detection mechanism that detects the vibration of the washing tub / dehydration tank 108 will be described. FIG. 2 is a block diagram illustrating an example of a control system of the washing machine 101. 2 includes an acceleration sensor 117, a first amplifying device 201, a second amplifying device 202, a changeover switch 205, an A / D converter 206, a control device 216, a rotation speed detecting device 217, and various operation switches 218. A motor control device 219, a motor 220, various valves 221, and a display device 222.

The acceleration sensor 117 is a Z-axis output that is an acceleration detection signal in the rotation axis direction of the washing tub / dehydration tub 108 and an acceleration detection signal X in a direction orthogonal to the rotation axis direction of the washing tub / dehydration tub 108. A shaft-side output and a Y-axis side output that is an acceleration detection signal including a rotational direction component of the washing tub / dehydration tub 108 that is orthogonal to the rotation axis direction of the washing tub / dehydration tub 108 and also perpendicular to the X axis are output. .

  The X-axis side output from the acceleration sensor 117 is amplified by the first amplifying device 201, and the Z-axis side output is amplified by the second amplifying device 202. The Y-axis side output is amplified by the third amplifying device 203. Here, the amplification factor (gain) of the first amplification device 201 is set to be 10 times larger than the amplification factor (gain) of the second amplification device 202.

  One of the output of the first amplifying device 201 and the output of the second amplifying device 202 is selected by the changeover switch 205 and sampled at a predetermined sampling interval by the A / D converter 206. The output of the A / D converter 206 is input to the control device 216, and the acceleration in each axial direction is evaluated in the control device 216. In addition, control signals from various operation switches 218 for performing various operations on the washing machine 101 are input.

  Further, the Y-axis side output via the third amplifying device 203 and the filter circuit 207 is input to the control device 216. This filter circuit 207 is configured by a filter having a steep cut effect including a notch filter circuit, and is set to pass a signal of 1 Hz to 30 Hz. Thereby, it is possible to remove the noise waveform due to the power supply frequency from the Y-axis side output.

  The control device 216 outputs a control signal to the motor control device 219 and controls the rotation of the motor 220. For example, the control device 216 can control the rotation speed of the motor 220. In addition, the control device 216 controls the opening / closing and opening / closing states of a valve (not shown) that controls water injection into the washing tub / dewatering tub 108 and the drain valve 115. In FIG. 2, a plurality of valves are collectively referred to as various valves 221 and the like. The display device 222 displays information related to the operation mode and operation details. As the display device 222, display using a lamp, display using an LCD screen, or the like is used.

  Next, an example of the acceleration sensor 117 will be described. FIG. 3 is a plan view and a cross-sectional view showing an example of the acceleration sensor. 3A is a plan view, and FIG. 3B is a cross-sectional view taken along line BB in FIG. 3A.

  The acceleration sensor 117 is a triaxial acceleration sensor capable of detecting triaxial acceleration orthogonal to the XYZ axis directions. The acceleration sensor 117 includes a casing 1, an acceleration detection unit 2, a circuit board 3, a cover 4 and a terminal 5. A recess 11 is formed in the casing 1. The acceleration detector 2 is provided with a diaphragm 21 made of a rectangular thin metal plate. On one surface of the diaphragm 21, a weight 22 is fixed at the center, and the weight 22 is stored in the recess 11. A thin film piezoelectric element 23 is fixed in close contact with the other surface of the diaphragm 21. Electrodes 24 and 26 are formed on the surface of the piezoelectric element 23. A wiring pattern is drawn out from the electrodes, and the wiring pattern is electrically connected to the extraction electrodes 25a to 25c. The diaphragm 21 may be a circular metal thin plate or the like in addition to a rectangular metal thin plate such as a rectangular shape or a square shape.

  The extraction electrodes 25 a to 25 c are connected to an amplifier circuit on the circuit board 3 by wire bonding (not shown) so that an output from the amplifier circuit on the circuit board 3 appears at the terminal 5. An IC chip 31 that constitutes an amplifier circuit is disposed on the circuit board 3.

  When the acceleration sensor 117 performs an acceleration motion, the diaphragm 21 is distorted by the inertia of the weight 22. This distortion acts on the piezoelectric element 23, and a voltage corresponding to the degree of distortion of the diaphragm 21 appears on the electrodes 25 a to 25 c, which is amplified by the amplifier circuit on the circuit board 3 and output from the terminal 5. In this configuration, since the direction of acceleration applied to the acceleration sensor 117 is reflected in the degree of distortion of the diaphragm 21, the acceleration in the three-dimensional direction can be detected individually.

  For example, in the X-axis direction and the Y-axis direction shown in FIG. 3, the pair of electrodes (for example, the electrode 24 a and the electrode 24 b) disposed to face the center of the diaphragm 21 are generated according to compression or tension. The piezoelectric element 23 is set so that the polarities of the charges are opposite to each other. In addition, in the substantially triangular four electrode portions 26, the piezoelectric elements 23 are set so that the polarities of the charges generated in response to compression or tension are all the same.

  According to this example, when the acceleration sensor 117 receives acceleration in the X-axis direction, the weight 22 is tilted in the X-axis direction, and a voltage appears at the extraction electrode 25a. This voltage is reversed in polarity when the direction of acceleration differs by 180 degrees. For example, when the acceleration sensor 117 receives acceleration in the Y-axis direction, the weight 22 is tilted in the Y-axis direction, and a voltage appears at the extraction electrode 25b. This voltage also reverses its polarity when the direction of acceleration differs by 180 degrees. For example, when the acceleration sensor 117 receives acceleration in the Z-axis direction, the weight 22 moves in the Z-axis direction, and a voltage appears at the extraction electrode 25c. This voltage also reverses its polarity when the direction of acceleration differs by 180 degrees. In this way, acceleration applied in the XYZ triaxial directions is output as an electrical signal.

  Next, an example of the operation procedure of the dehydrating operation of the washing machine shown in FIGS. 1 and 2 will be described. FIG. 4 is a flowchart showing an example of the operation procedure of the dehydrating operation of the washing machine 101. When the motor 111 is energized, starts rotating, and starts dehydration (step S400), the number of rotations of the motor 111 increases. At this time, first, the X-axis side output is selected by the changeover switch 205 of FIG. 2 (step S401), and it is further determined whether the X-axis side output is equal to or lower than the first voltage (step S402). This voltage is detected by the control device 216.

  In step S402, it is determined whether or not lateral vibration of an unacceptable magnitude has occurred in the washing tub / dehydration tub 108. The value of the first voltage may be obtained based on a test result obtained by attaching an acceleration sensor to the actual machine of the washing machine, performing a test in which abnormal vibration actually occurs during the dehydrating operation.

  If the determination in step S402 is NO, it is determined that an unacceptable lateral vibration (vibration in the X-axis direction) has occurred, and therefore processing for stopping the rotation of the washing tub / dehydration tub 108 is performed. That is, the control device 216 sends a signal to the motor control device 219 to stop the motor 220 and stops the motor 220. At this time, a warning alarm may be notified using a warning sound generator (not shown).

  If the determination in step S402 is NO, the laundry to be dehydrated is in a state of being biased in the washing tub / dehydration tub 108, the weight balance is remarkably deteriorated, and further dehydration is difficult. It means that. Accordingly, the rotation of the washing tub / dehydration tub 108 is stopped as shown in step S403.

  If the determination in step S402 is YES, the process proceeds to step S404 to determine whether the Y-axis side output is equal to or higher than the first frequency value. If the Y-axis side output is equal to or higher than the first frequency value, step S404 is performed. Proceed to S405, otherwise return to the previous stage of step S402. That is, if the determination here is YES, it indicates that the rotation speed of the washing tub / dehydration tank 108 is equal to or higher than a specific rotation speed (first rotation speed), and abnormal vibration at the initial stage of dehydration. Has not happened, and can move on to the next step.

  For example, about 8 to 10 Hz is set as the first frequency value of the Y-axis side output. As a result, the first rotation speed is approximately 600 rotations (rotation speed / minute). From this rotational speed, the vibration mode is set by gradually switching from the vibration mode of transverse vibration (vibration in the X-axis direction) to the vibration mode of longitudinal vibration (vibration in the Z-axis direction). If step S404 is NO, it is still a vibration mode of transverse vibration, and there is a possibility that the rotation must be stopped due to intensification of vibration, so step S402 is executed again.

  On the other hand, if it is determined in step S404 that the output on the Y-axis side is equal to or higher than the first frequency value, this means that the vibration mode of the washing tub / dehydration tub 108 is becoming a vibration mode of longitudinal vibration. . Therefore, when the determination in step S404 is YES, the process proceeds to step S405 to shift to a vibration detection mode in which longitudinal vibration is detected.

  In step S405, the Z-axis side output is selected by the changeover switch 205 in FIG. 2, and it is determined whether the Z-axis side output is equal to or lower than the second voltage (step S406). The second voltage is set as a detected value of vibration at a level at which the vertical vibration generated in the washing tub / dehydration tub 108 should be subjected to some treatment (a level that can be tolerated but cannot be ignored).

  In step S406, if the Z-axis side output is equal to or lower than the second voltage, it is determined whether the Y-axis side output is equal to or higher than the second frequency value (step S407). Otherwise, the process proceeds to step S410.

  Here, the second frequency value of the output on the Y-axis side is set from the frequency at which the rotation speed becomes a level at which it can be determined that there is no problem even if the washing tub / dehydration tank 108 reaches the maximum rotation speed as it is (this). The rotation speed is set as the second rotation speed). For example, when the set maximum rotation speed is 1000 rotations per minute, a rotation speed of about 800 rotations per minute is set as the second rotation speed as the second rotation speed. As the second frequency value, about 13 to 14 Hz is set.

  For example, when the maximum rotation speed is about 1000 rotations, if abnormal vibration does not occur in the vicinity of 800 rotations, the rotation continues as it is, and even if it reaches 1000 rotations, abnormal vibration will occur in the meantime. Absent. This is because a stable rotational state has already been reached in the state of 800 revolutions. From such a technical background, the second frequency value (second rotation speed) of the Y-axis side output is set.

  If the determination in step S407 is yes, the process proceeds to step S408, and the rotational speed is increased to a predetermined maximum rotational speed. Then, it is determined whether or not the elapsed time of the dehydration process at the maximum number of revolutions is a predetermined time (step S409). If the predetermined time has elapsed, the process proceeds to step S416, where the washing tank / dehydration tank 108 is set. A process for stopping the rotation is performed, and the dehydration is terminated (step S417). On the other hand, if the predetermined time has not elapsed, the process returns to the previous stage of step S406, and step S406 and subsequent steps are repeated again.

  Even if the determination in step S409 is NO, if dehydration at the maximum rotational speed has progressed without any problem, the determination in step S406 is YES, the determination in step S407 is also YES, and the processing in steps S406 to S409 is performed. The process is repeated until a predetermined time elapses.

  If any abnormal vibration occurs during dehydration at the maximum rotation speed, the determination in step S406 is NO, and the processing in step S410 and subsequent steps is executed.

  In step S410, it is determined whether or not the current Y-axis side output value is a specific frequency value, for example, about 8 to 10 Hz. Stop rotating. If the current Y-axis side output value is equal to or higher than the specific frequency value, the process proceeds to step 411, and the rotation speed of the washing tub / dehydration tank 108 is set so that the Y-axis side output value becomes the specific frequency value. Is reduced to a specific rotation speed (for example, 400 rotations). Then, the reduced rotational speed is maintained for a predetermined time (step S412), and it is determined again whether the Z-axis side output is equal to or lower than the second voltage (step S413).

  If the Z-axis side output is not equal to or lower than the second voltage, step S415 is executed, and the washing tub / dehydration tub 108 is stopped. If the determination in step S413 is YES, it is determined whether the time (dehydration time) corresponding to the adjusted rotational speed has elapsed (step S414). If the predetermined time has elapsed, the process proceeds to step S416. Otherwise, return to the previous stage of step S412. The elapsed time determined in step S414 is set to a length of about 1.5 to 3 times the elapsed time determined in step S409.

  In this way, by lowering the rotation of the washing tub / dehydration tub 108 to a level where vibration can be allowed, dehydration can be automatically performed to the end without interrupting dehydration.

  Although not shown in FIG. 4, when the rotation of the washing tub / dehydration tub 108 is stopped in step S403, the following steps may be performed. That is, after step S403, water is injected and the washing tub / dehydration tub 108 is rotated a plurality of times in the forward and reverse directions. By doing so, the bias of the laundry is eliminated. Thereafter, the processing from step S401 is executed again. By doing so, dehydration can be automatically restarted.

  In the operation described above, the output on the X-axis side is selected in step S401 at the initial stage of rotation, and the output on the Z-axis side is selected instead of the output on the X-axis side when the rotation speed reaches a certain level. By doing so, the lateral vibration (vibration in the X-axis direction) in the initial rotation of the washing tub / dehydration tub 108 is performed with high sensitivity via the first gain device 201 having a high gain, and the rotational speed is increased to some extent, so that the vertical vibration , The detection of the acceleration in the Z-axis direction via the low gain second amplifying device 202 is performed in a detection mode that can cope with a stronger input.

  As described above, in this embodiment, the axis of acceleration to be detected is changed in accordance with the change in the vibration mode that changes depending on the number of rotations of the washing tub / dehydration tub, and the amplification factor is switched in accordance with the vibration mode. This increases the gain of the amplifying device for vibrations with small acceleration, thereby increasing the detection sensitivity, and weakens the gain of the amplifying device for vibrations with large acceleration, thereby detecting the device (for example, an A / D converter). Can be prevented from being saturated by strong input. In this way, optimal vibration detection according to the vibration mode can be realized while ensuring a wide dynamic range.

  Further, an output on the X-axis side of the acceleration sensor 117 that detects vibration in a direction (horizontal direction) orthogonal to the rotation axis of the dehydration tank, and Z of the acceleration sensor 117 that detects vibration in the rotation axis direction (vertical direction) of the dehydration tank. In order to switch the shaft side output, since the switching is performed based on the Y axis side output of the acceleration sensor 117 that is orthogonal to the horizontal direction and also orthogonal to the vertical direction, a signal necessary for detecting abnormal vibration is transmitted only by the acceleration sensor 117. It becomes possible to output.

  Furthermore, by setting the output on the Y-axis side of the acceleration sensor 117 to an output caused by the rotation direction, it is not necessary to provide a separate rotation speed detection means such as an encoder, and the necessary detection can be performed only by the acceleration sensor 117. It becomes.

  Further, by using an acceleration sensor having a function capable of individually detecting acceleration in the three-dimensional direction as the acceleration sensor 117, there is no need to use an encoder or other sensor for detecting the number of rotations, and the number of parts can be reduced. It becomes possible, and the cost can be reduced.

Furthermore, since the filter circuit 207 is provided in the detection path of the Y-axis side output, the commercial power supply frequency of the motor 111 for rotating the washing tub / dehydration tub 108 is mixed in the output of the acceleration sensor 117. Therefore, it is possible to reliably detect the vibration associated with the rotation of the washing tub / dehydration tub 108.

  As Example 2, the following examples can be given. FIG. 5 is a block diagram illustrating another example of the vibration detection mechanism of the washing machine. In the configuration shown in FIG. 5, the three-axis outputs of the acceleration sensor 117 are connected to DSPs (digital signal processors) 501, 502, and 503 each having an A / D converter. In the DSPs 501 and 502, signal processing corresponding to each of the X-axis side output and the Z-axis side output is performed, and the output is switched by the changeover switch 205. Also in this case, effective vibration detection can be performed according to the difference in the direction of acceleration due to the difference in vibration mode and the difference in the intensity of acceleration.

  The DSP 503 is also configured to perform a function as a high-precision filter circuit at the same time as performing signal processing according to the Y-axis side output. In this way, the Y-axis side output is input to the control device 216 via the DSP 503.

  In addition, the following embodiments can be given. In the configuration shown in FIG. 2, amplifying devices having different amplification factors are arranged for the Z-axis side output and the X-axis side output, respectively. As a modification, the amplification factor may be switched by a single amplification device. In this case, when the X-axis side output is selected, the low amplification factor is selected, and when the Z-axis side output is selected, the high amplification factor is selected.

  The dehydrating tank to which the present invention can be applied is of a so-called horizontal type or an oblique type whose rotation axis is not in the vertical direction (a structure in which the rotation axis is inclined at 45 degrees or the like with respect to the vertical direction). May be.

  In the present invention, the acceleration sensor 117 is a triaxial acceleration sensor that can detect acceleration in three axes orthogonal to the XYZ axis directions, but is not limited to this, and the X axis direction, the Y axis direction, Three acceleration sensors each corresponding to the Z-axis direction may be used.

It is sectional drawing which shows an example of the cross-sectional structure of a washing machine. It is a block diagram which shows an example of the control system of a washing machine. It is the top view (A) and sectional drawing (B) which show an example of an acceleration sensor. It is a flowchart which shows an example of the operation | movement procedure of the spin-drying | dehydration operation of a washing machine. It is a block diagram which shows another example of the control system of a washing machine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 2 Acceleration detection part 3 Circuit board 4 Cover 5 Terminal 11 Recess 21 Diaphragm 22 Weight 23 Piezoelectric element 24 Electrode 25a-25c Extraction electrode 26 Electrode 31 IC chip 101 Washing machine 102 Outer structure 103 Leg part 104 Base 105 Outer tank 106 Hanging member 107 Spring 108 Washing tub / dehydration tub 109 Agitation blade 111 Motor 112 Rotating shaft 113 Bearing 114 Laundry 115 Drain valve 116 Flexible hose 117 Acceleration sensor 201 First amplifying device 202 Second amplifying device 203 Third amplifying device 205 Switch 206 A / D Converter 207 Filter Circuit 208 A / D Converter 216 Control Device 217 Rotational Speed Detection Device 218 Various Operation Switches 219 Motor Control Circuit 220 Motor 221 Various Valves 222 Display Device 501 DSP, 502 DSP, 503 DSP

Claims (4)

In a washing machine with a dehydrating function equipped with an acceleration sensor for detecting acceleration,
At least a dehydration tank for dehydration;
First acceleration detection means for detecting vibration in a direction perpendicular to the rotation axis of the dehydration tank;
Second acceleration detection means for detecting vibration in the direction of the rotation axis of the dehydration tank;
Third acceleration detection means for detecting vibration in a direction orthogonal to the vibration direction detected by the first acceleration detection means and orthogonal to the vibration direction detected by the second acceleration detection means;
Have
A washing machine, wherein the signal from the first acceleration detection means and the signal from the second acceleration detection means are switched by the detection signal of the third acceleration detection means to detect the vibration of the dewatering tub.   The third acceleration detection means is an acceleration detection means for detecting a vibration in a rotation direction of the dehydration tank, and detects a vibration orthogonal to a vibration direction detected by the second acceleration detection means. The washing machine according to 1.   The laundry according to claim 1 or 2, wherein the first acceleration detection means, the second acceleration detection means, and the third acceleration detection means are configured by an integrated three-axis acceleration sensor. Machine.   The washing machine according to any one of claims 1 to 3, wherein a noise filter is provided in a detection path of the third acceleration detection means.

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