JP4501980B2 - Washing machine - Google Patents

Description

  The present invention relates to a washing machine that cleans laundry stored in a rotating drum by rotationally driving a rotating drum disposed in a water tub.

A conventional drum type washing machine of this type will be described with reference to the longitudinal sectional view of FIG. In the washing machine body 1, a water tank 2 is supported in a suspended state by a suspension structure (not shown). In the water tank 2, a drum 3 formed in a bottomed cylindrical shape is rotatably supported with its axial direction inclined downward from the front side to the back side. On the front side of the aquarium 2 is formed a clothing doorway 4 leading to the opening end of the drum 3, and by opening and closing a door 5 that opens and closes an opening provided on the upward inclined surface of the front side of the washing machine body 1. The laundry can be taken in and out of the drum 3 through the clothing entrance 4.

  The drum 3 has a large number of through holes 6 formed in the peripheral surface thereof that communicate with the water tank 2, and is provided with stirring protrusions 15 for stirring clothes at a plurality of positions on the inner peripheral surface. The drum 3 is rotationally driven in the forward and reverse directions by a motor 7 attached to the back side of the water tank 2. In addition, a water injection pipe 8 and a drain pipe 9 are connected to the water tank 2 to perform water injection and drainage into the water tank 2 by controlling a water injection valve and a water discharge valve (not shown).

  When the door 5 is opened, laundry and detergent are put into the drum 3, and the operation is started by an operation on the operation panel 10 provided on the front surface of the washing machine body 1, for example, a water injection conduit is provided in the water tank 2. A predetermined amount of water is injected from 8 and the drum 3 is rotationally driven by the motor 7 to start the washing process. By the rotation of the drum 3, the laundry accommodated in the drum 3 is lifted in the rotation direction by the stirring protrusion 15 provided on the inner peripheral wall of the drum 3, and the stirring operation of dropping from the lifted appropriate height position is repeated. Therefore, the laundry is washed by the action of tapping. After the required washing time, the dirty washing liquid is discharged from the drain pipe 9, and the process proceeds to a dehydration process in which the drum 3 is rotated at high speed. The washing liquid contained in the laundry is dehydrated by this dehydrating operation, and then a water rinsing process is performed by pouring water into the water tank 2 from the water pouring line 8. Also in this rinsing step, the laundry stored in the drum 3 is rinsed by repeating a stirring operation in which the laundry is lifted and dropped by the stirring protrusion 15 by the rotation of the drum 3. After the predetermined rinsing process, the rinsing station is similarly discharged from the drain pipe 9, and the process proceeds to a dehydration process in which the drum 3 is rotated at a high speed. After a dehydration operation for a predetermined time, all processes are completed.

  In addition, on the back surface of the motor 7, a rotation detection unit 14 including a position detection element that detects the position of the rotor (rotor) of the motor is provided in order to detect the rotation state.

  During the dehydration operation, the drum rotation speed is high-speed operation (for example, 1000 r / min), so that the vibration of the water tank 2 is increased due to clothing unevenness (unbalance distribution) in the drum. May increase the user's anxiety and may damage the device itself.

For this reason, during the dehydration operation, the torque applied to the motor by the control unit at a relatively low speed (for example, 100 r / min) is made constant, and fluctuations in the rotation speed of the drum in that case are detected, thereby unbalanced clothing. After detecting the distribution, it is determined whether or not it is possible to shift to the dehydration process (not shown), and vibration of the water tank during high-speed operation is suppressed (for example, see Patent Document 1).
JP 2007-068813 A

  In the above-described conventional method for detecting clothing imbalance during the dehydration process, since the clothing imbalance distribution is detected during low-speed rotation, moisture contained in the clothing is not sufficiently removed and water is easily contained or contained. There is a problem that the accuracy of vibration during high-speed dewatering rotation is low, which is easily affected by the quality of the fiber and the type and amount of clothing.

  In addition, since the clothing imbalance detection method at a relatively low speed mainly detects the static balance, for example, the distribution of the clothing imbalance gives a rotational motion to the center of gravity of the drum. Since it is difficult to detect the balance, there is a problem that it is difficult to determine whether or not to shift to the dehydration operation because the determination criteria for the dehydration shift are reduced.

  There is also a method of detecting vibration during dehydration by attaching a physical imbalance detection means such as an acceleration sensor to the water tank, but there is a problem that the acceleration sensor itself is expensive and increases the cost of the equipment. is doing.

  The present invention solves the above-mentioned conventional problems, and detects vibration of the drum by measuring the acceleration torque of the motor in the rotation increasing section during the dehydration operation, and provides a low-cost and high-precision vibration detection means. An object of the present invention is to provide a drum-type washing machine provided.

In order to solve the above conventional problems, the drum type washing machine of the present invention, the rotational speed of the drum during dehydration, measuring the integrated acceleration torque during rising from the predetermined revolution N1 to N2, a predetermined rotational The values of the numbers N1 and N2 are the values of the rotational speed shifted from the inflection point of the rotational speed during the start of dehydration, and the rotational speed values in the vicinity where the torque applied to the motor takes the minimum value while the rotational speed is increasing, Vibration is detected according to the measured accumulated acceleration torque, and the number of rotations of the drum during the dehydration operation is set based on the detected vibration .

  This makes it possible to detect the vibration of the water tank during the dehydration operation with low cost and high accuracy without providing a separate physical imbalance detection means such as an acceleration sensor.

  Further, the drum type washing machine of the present invention can perform a low vibration dehydration operation by determining whether or not the rotation speed can be increased during the dehydration rotation based on the detected vibration.

  The drum type washing machine of the present invention can provide a drum type washing machine having vibration detection means that is inexpensive and highly accurate without specially providing a physical vibration sensor such as an acceleration sensor.

A first invention includes a drum having a rotation center axis in a substantially horizontal direction and accommodating a laundry to perform a rotational motion, and a water tub enclosing the drum rotatably and elastically supported in a washing machine body And a motor that rotationally drives the drum, a rotational speed detection device that detects the rotational speed of the motor, and a control unit that controls the rotation of the motor based on a detection output of the rotational speed detection device. The unit accelerates the rotation of the drum by generating a predetermined acceleration torque in the motor, measures the accumulated acceleration torque while the rotation speed increases from the predetermined rotation speed N1 to N2, and determines the predetermined rotation speed The values of N1 and N2 are the values of the rotational speed shifted from the inflection point of the rotational speed during dehydration start-up, and the rotational speed values in the vicinity where the torque applied to the motor takes the minimum value while the rotational speed is increasing, the measured integrated acceleration torque Depending detects vibrations, by which is adapted to set the rotational speed of the drum during the dewatering operation by the detected vibration, during dewatering operation, to detect the vibration of the water tub at relatively high speed during operation, the drum It is possible to accurately detect the dynamic imbalance generated by the clothing imbalance distribution.

Further , the acceleration torque overshoot at the rotational speed N1 and the undershoot of the acceleration torque at the rotational speed N2 are not affected when integrating the motor acceleration torque from the rotational speed N1 to N2. Thereby, the accuracy of the numerical value of the integrated acceleration torque is improved, and vibration can be detected with high accuracy.

In addition, particularly at the beginning of dehydration, it is less susceptible to the residual water contained in the clothing, and the vibration level can be detected with high accuracy.

Further, when it is determined that the vibration is large (imbalance is large), without increasing the rotation speed, when it is determined that the small vibration is (unbalance is small) is to increase up to a predetermined high-speed rotation speed Thus, the vibration of the device itself can be suppressed.

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

(Embodiment 1)
Figure 1 is a shows the schematic configuration of a control device for controlling the operation of the drum type washing machine according to a first embodiment of the present invention. The schematic structure of the drum type washing machine is the same as that of the conventional example shown in FIG.

  In the control device shown in FIG. 1, AC power from a commercial power source 20 is rectified by a rectifier 21, and DC power smoothed by a smoothing circuit including a choke coil 22 and a smoothing capacitor 23 is used as drive power, and a motor is driven by an inverter circuit 24. 7 is driven to rotate. Further, the rotation of the motor 7 is controlled based on the driving instruction input from the input setting unit 25 and the monitoring information of the driving state detected by each detecting means (not shown), and the water supply valve 27 is controlled by the load driving unit 26. The operation of the drain valve 28, the blower fan 12, and the heater 29 is controlled.

  The motor 7 includes a stator having three-phase windings 7a, 7b, and 7c and a rotor having a two-pole permanent magnet, and is configured as a DC brushless motor provided with three position detection elements 30a, 30b, and 30c. The rotation is controlled by a PWM control inverter circuit 24 configured by the switching elements 24a to 24f. The rotor position detection signals detected by the position detection elements 30a, 30b, and 30c are input to the control unit 31 configured by a microcomputer. Based on the rotor position detection signal, the drive circuit 32 performs PWM control, that is, pulse width modulation control, of the on / off states of the switching elements 24a to 24f, thereby energizing the three-phase windings 7a, 7b, and 7c of the stator. Control and rotate the rotor at the required number of revolutions.

  The control unit 31 includes a rotation speed detection unit 33 to which detection outputs of the three position detection elements 30a, 30b, and 30c are input. The rotation speed detection unit 33 detects the cycle whenever the signal state of any of the three position detection elements 30a, 30b, and 30c changes, and calculates the rotation speed of the rotor from the cycle. Since the detection output of the rotation speed detector 33 corresponds to the rotation speed of the drum 3, in the following description, the rotation speed of the drum 3 is obtained by the detection output of the rotation speed detector 33, and the obtained numerical value. On the other hand, both during the dehydration start-up and during the dehydration steady rotation, the rotational speed is controlled by providing feedback to each target rotational speed.

  The characteristics of the vibration detection method in the present embodiment will be described below with reference to FIG.

  FIG. 2 is a diagram showing the operation of vibration detection, in which the horizontal axis shows the time elapsed at the start of the dehydration operation, and the vertical axis shows the increase table of the dehydration speed of the drum 3 and the torque T applied to the motor. In this embodiment, the rotational speed acceleration is 10 r / min per second.

  As shown in FIG. 2, the drum rotation speed shifts to high speed rotation as indicated by the curve S as time passes, while the torque applied to the motor gradually decreases as indicated by the curve T.

  This is because a large amount of moisture contained in clothing acts as a large moment of inertia at the beginning of startup, but since the moisture is gradually removed by centrifugal force and its value decreases, the torque applied to the motor also decreases. Show you coming.

Further, the rotation speed N3 of the first inflection point (K) having a large change in the rotation speed shifted from the low speed rotation to the high speed rotation is about 400 r / min, while the predetermined dehydration rotation speed N4 is about 700 r / mi.
Immediately before reaching n, there is a second inflection point (P), and the motor torque changes greatly at any inflection point.

In FIG. 2, the predetermined rotational speed N1 for measuring the integrated acceleration torque is set to 600 r / min, the predetermined rotational speed N2 is set to 620 r / min, and N3 = 400 r / min of the first inflection point (K). , and N4 = 700r / min of the second inflection point (P), is set to the rotational speed of the Shifts.

This is because the motor rotation control causes the motor input to increase more than necessary by overshooting the applied torque to the motor at the inflection point (K) of about 400 r / min at low speed when the rotational speed greatly changes. This is to prevent the possibility of obtaining a normal numerical value for torque detection.

  In addition, at the second inflection point (P), the torque applied to the motor at the time of shifting to steady rotation is undershooted, causing the torque to be reduced more than necessary, and normal detection of torque cannot be obtained. This is to prevent this.

  In addition, the setting of the rotation speeds N1 and N2 is not the section (A) in which the torque increases due to the large moment of inertia of a large amount of moisture contained in the clothes at the start of the dehydration start, but the torque during the dehydration start operation is set to a substantially minimum value. In the vicinity of the section (B), the detected numerical value is stabilized.

  The amount of work generated by clothing imbalance is detected as follows.

  The acceleration torque T applied to the motor in a section between the predetermined rotation speed N1 (600 r / min) and the predetermined rotation speed N2 (620 r / min) is given by the following expression.

T = J × Δω + T ′ (1) In this equation (1), J is the moment of inertia around the rotation axis including the drum and clothing, and Δω (rad / s ² ) is the current rotational speed. The difference between N ₀ and the target rotational speed _NT is divided by the discrete time Δt until feedback, and can be expressed by the following equation.

Δω = 2π × (N _T −N ₀ ) / Δt (2) In addition, T ′ is a centrifugal force generated due to clothing imbalance or an excitation force due to a rotational moment generated around the center of gravity of the water tank. This is a torque for resisting and accelerating, and an extra acceleration torque required for the motor.

Since the kinetic energy of the rotating body can be expressed by (1/2) × (moment of inertia) × (angular velocity) ² , the integrated value E, which is also the kinetic energy of the acceleration torque T in the section from the rotational speed N1 to N2, has the drum. This is the sum of the kinetic energy and the work amount W required by the vibration generated by the imbalance of the clothes, and is expressed by the following equation.

E = (1/2) × J (N ₂ ² −N ₁ ² ) × (2π / 60) + W (3) In this equation (3), if the rotational speed N1 is set relatively close to N2, The influence of the amount of clothing of the first term in the equation (3) is reduced, and the work amount W generated by the clothing imbalance can be detected from the integrated value E of the acceleration torque T on the left side.

  Furthermore, the rotation speeds N1 and N2 for detecting vibration are set in the vicinity of a section (B) where the torque applied to the motor takes a minimum value. In the section (A) in which the torque applied to the motor is increasing, the influence of moisture contained in the clothing becomes large. Therefore, it is possible to detect vibration with high accuracy by avoiding this section.

  Next, a dehydration start-up operation is performed by changing the actual type of clothing, and the correlation between the kinetic energy W due to clothing imbalance measured between the predetermined rotational speeds N1 and N2 and the water tank amplitude value will be examined.

  FIG. 3 is a plot of the measured value W detected by the equation (2) on the horizontal axis and the amplitude value of the vibration of the water tank on the vertical axis while changing the type of clothing, regardless of the type of clothing. It is shown that the amplitude value and the measured value W of the work amount are substantially proportional to each other. If the measured value W is large, it can be seen that the vibration is large. It is possible to detect an unbalanced state of clothing.

  FIG. 4 is a flowchart showing vibration detection and setting of the dewatering rotation speed, and Table 1 is a table of the allowable rotation speed and vibration value of the drum.

  Hereinafter, the control of the dehydration speed setting will be described with reference to FIG. 4 and Table 1.

  As shown in FIG. 4, when the dehydration operation is started in step 100 {displayed as (S100) below}, the drum rotation speed increases in (S101), and reaches the predetermined rotation speed NI in (S102), In (S103), the numerical value of the work amount W is reset, and W (0) = 0 is set.

  The rotational speed is further increased (S104), and while detecting the acceleration torque T of the motor (S105), the work amount W during the Δt time until the rotational speed increases to the predetermined rotational speed N2 is detected (S106).

  If the predetermined rotational speed N2 is reached (S107), the threshold value is compared with the detected work amount W and the preset table shown in Table 1 (S108).

  In this embodiment, as shown in Table 1, the threshold value is provided in four stages, and the range of each work amount W is set. For example, if the work amount W is in the range of 1 to 80, the threshold value 1 is set. However, since the unbalance is very small, the dehydration rotation speed is high speed 900 r / min or more (S109).

  On the other hand, if it is detected that the threshold value 4, that is, the work amount W is greater than 201, the imbalance is very large, and the dehydration operation is determined to be dangerous. The process ends (S113).

When it is determined that the amount of unbalance of the threshold value 2 is slightly large, the above (S109)
Further, the rotational speed is lowered slightly to 800 r / min (S110), and if the unbalance of the threshold value 3 is slightly larger, it is set to a lower speed of 700 r / min (S111) to perform the dehydration operation.

  The operation and action of the washing machine configured as described above will be described below.

  This is a control for measuring the kinetic energy W at the time of passage from the predetermined rotational speed NI to N2 during dehydration and detecting the unbalanced state of the clothing from the correlation with the water tank amplitude value. It is possible to provide a drum type washing machine having an inexpensive and highly accurate vibration detecting means without specially providing a mechanical vibration sensor.

  In addition, overshoot and undershoot of the applied torque from the motor occurred because the predetermined rotation speeds NI and N2 were set while avoiding the rotation speed inflection points (K) and (P) during dehydration startup. Even in such a case, the accuracy of the numerical value of the integrated acceleration torque is increased without being affected by this, and vibration can be detected with high accuracy.

  Since the predetermined rotation speeds NI and N2 are set avoiding the section (A) where there is a lot of residual water in the clothes, it is detected accurately in the section where there is no influence of the residual water contained in the clothes at the start of dehydration. The vibration level can be detected.

  A threshold value is set for the detected work amount W, and the control means determines whether or not to increase the rotational speed during the dehydrating operation by comparing with the threshold value by the detected vibration (clothing imbalance distribution state). If it is determined that the vibration is large (unbalance is large), it is determined that the vibration is small (unbalance is small) without increasing the rotational speed. In this case, it is possible to increase the rotational speed to a predetermined high speed, thereby suppressing the vibration of the device itself, and a low-vibration drum type washing machine can be provided.

  As described above, according to the present embodiment, it is possible to provide a drum type washing machine equipped with an inexpensive and accurate vibration detection method without providing physical vibration detection means such as an acceleration sensor.

  Although the configuration of the embodiment described above is applied to an oblique drum type drum-type washing machine in which the rotary drum 3 is inclined, the same applies to a general configuration in which the rotary drum 3 is horizontally arranged. Can be applied to.

  Needless to say, the same effect can be obtained by using an equivalent configuration as long as the electrical device has a rotating drum and can detect the torque applied to the motor as well as the drum type washing machine.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide a drum-type washing machine with a highly accurate vibration detection means without providing a physical vibration sensor such as an acceleration sensor for the vibration of the water tank during the dehydration operation. .

The circuit diagram which shows the control apparatus of the drum type washing machine in Embodiment 1 of this invention The figure which shows the vibration detection system used for the drum type washing machine The figure which shows the graph example of the vibration detection value of the drum type washing machine, and the vibration value of a water tank Flow chart showing vibration detection and setting of dehydration speed of the drum type washing machine Sectional drawing which shows schematic structure of the conventional drum type washing machine

DESCRIPTION OF SYMBOLS 1 Washing machine main body 2 Water tank 3 Drum 7 Motor 14 Rotation detection part (device)
20 commercial power supply 30a, 30b, 30c position detection element 31 control unit 32 drive circuit 33 rotation speed detection unit (device)

Claims (1)

A drum having a rotation axis in a substantially horizontal direction and containing a laundry to rotate, a water tank enclosing the drum rotatably and elastically supported in the washing machine body, and rotating the drum A motor for driving, a rotation speed detection device for detecting the rotation speed of the motor, and a control unit for controlling the rotation of the motor based on a detection output of the rotation speed detection device. The rotation of the drum is accelerated by generating a predetermined acceleration torque, and the integrated acceleration torque is measured while the rotation speed increases from the predetermined rotation speed N1 to N2. The values of the predetermined rotation speeds N1 and N2 are: The rotational speed value shifted from the inflection point of the rotational speed during dehydration start-up, and the rotational speed value in the vicinity where the torque applied to the motor takes a minimum value while the rotational speed is increasing , Depending on the vibration And knowledge, washing machine which is adapted to set the rotational speed of the drum during the dewatering operation by the detected vibration.