JP4835673B2 - Washing machine - Google Patents

Description

  The present invention relates to a washing machine having a cloth amount sensor for detecting a cloth amount that is an amount of laundry put in a drum.

  An example of the structure of the drum type washing machine is shown in FIG. In the washing machine body 1, a water tank 2 is supported in a suspended state by a suspension structure (not shown). A drum 3 formed in a bottomed cylindrical shape is supported in the water tank 2 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 the door 5 that closes the opening provided in the upward inclined surface on the front side of the washing machine body 1 so as to be openable and closable, 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 (not shown) 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 stored in the drum 3 is lifted in the rotation direction by the stirring protrusion 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 has the effect of tapping and washing. After the required washing time, the dirty washing liquid is discharged from the drain pipe 9 and the washing liquid contained in the laundry is dehydrated by a dehydrating operation of rotating the drum 3 at a high speed. The rinsing process is performed by pouring water from 8. Also in this rinsing step, the laundry housed in the drum 3 is repeatedly washed with a stirring operation in which the laundry is lifted and dropped by the stirring protrusions by the rotation of the drum 3 to perform rinsing.

  This drum-type washing machine is provided with a function of drying laundry stored in the drum 3, and the air in the water tank 2 is exhausted and dehumidified by the circulation air passage 11 to heat and dry the air. The air is blown into the water tank 2 again. In the middle of the circulation air passage 11, a dehumidifying means such as an evaporator, a heating means such as a condenser, and a blower fan 12 serving as an air blowing means are provided. In the drying process using the circulation air passage 11, foreign matter such as lint generated from laundry such as clothes is circulated in the air circulated through the circulation air passage 11, and the eyes of the evaporator and the condenser are circulated. Since clogging, biting into the rotating part of the blower fan 12 and deposition on the inner surface of the blower fan 12 are likely to be hindered, foreign substances in the circulating air are trapped in the middle of the circulation blower path 11. A filter 13 to be removed is provided. A rotation detection unit 14 for detecting the rotation of the motor 7 is provided.

  In the drum type washing machine having the above-described configuration, the amount of laundry such as clothes put in the drum 3 is detected, and the washing time and the like are determined according to the amount of cloth. An example of a method for detecting the amount of cloth disclosed in Patent Document 1 will be described below with reference to FIG.

The cloth amount is detected by a control circuit (not shown) having a function of controlling the motor 7 for driving the drum 3 to rotate.

  When washing is started, first, the control circuit starts the motor 7 and a detection output is input from the rotation detection unit 14. The detection frequency of the rotation detection unit 14 changes linearly with the rotation of the motor 7. The control circuit increases the average voltage of the power supply voltage of the motor 7 by means of phase control when the input frequency from the rotation detector 14 is small, and decreases the average voltage when the frequency increases.

  In the cloth amount detection process, while performing rotation control, the average voltage applied to the motor 7 is gradually increased inside the control circuit to shift to high speed rotation so that the clothes are uniformly attached to the inner wall of the drum 3 by centrifugal force. To. In this state, the rotation of the motor 7 is stopped after continuing the rotation for a predetermined time. Thereby, the inertial rotation of the drum 3 is in a state where the motor 7 is rotated.

  At this time, as shown in FIG. 5, the rotation detection unit 14 converts the inertial rotational force of the drum 3 to gradually decrease due to the friction torque and stops the rotation, and outputs the result. In FIG. 5, the horizontal axis represents time, and the vertical axis represents the number of rotations of the drive motor (motor). The time from the stop of energization to the stop of the drum 3 is long when the amount of cloth is large and short when the amount of cloth is small. The cloth amount is detected by utilizing the fact that the difference in time required for the stop is proportional to the cloth amount.

  Here, when the weight of the cloth is m, the average radius of the cloth distributed on the inner periphery of the drum 3 is r, and the inertia moment of the drum 3 or the motor 7 is Jd, the inertia moment J of the cloth is obtained by Equation 1.

  Further, assuming that the generated torque of the motor 7 is T, the friction torque of the drum rotation shaft is Tb, and the angular acceleration of the drum 3 is α, these relationships are expressed by Equation 2.

  Since the angular acceleration α is expressed by Equation 3 as a function of the angular velocity ω and time t, if the average radius r of the cloth is constant as shown in Equation 4, the rotational speed, that is, the angular velocity ω, according to the weight m of the cloth. Changes.

That is, the cloth amount can be known by stopping the energization of the motor 7 to inertially rotate the drum 3 and measuring the change in the rotational speed in a certain time interval until the drum 3 stops.
JP-A-5-168786

  When the conventional cloth amount detection method is used, a proportional relationship between the time until the drum stops and the amount of cloth until the drum stops due to the friction torque is gradually obtained through experiments. . However, as can be seen from Equation 4, the proportional relationship between the time until the drum stops and the amount of cloth is not constant and varies depending on the washing machine due to the influence of the variation in the friction torque of the rotating shaft of the water tank. Also, in the dry operation, wet laundry is put into the aquarium unit, so if the number of rotations of the aquarium increases with the cloth amount detection operation sometimes sticking to the aquarium with a large unbalanced state, abnormal sounds and vibrations will be generated in the washing machine body. There is a problem of causing damage to members, etc., and there are methods for detecting the unbalanced state of the aquarium, such as detection due to uneven rotation of the drum and detection of the absolute value of acceleration using a vibration sensor. In such a low-speed rotation region, the instantaneous acceleration is large due to the size of the unbalance, but when the kinetic energy is small, the detection variation is large and difficult to detect accurately as a result of simple comparison of accelerations. Therefore, the threshold value for determining abnormal vibration is made strict, and even if the vibration does not cause the water tank to hit the main body, the cloth amount determination operation is stopped and the determination result of the cloth amount is fixed to a predetermined large rank. If the amount of cloth is judged to be larger than the actual amount of cloth, the amount of water and the amount of detergent at the time of washing will be displayed incorrectly, and the remaining time indicating the time until the end of drying will be similarly long. Compared to the case where the amount of cloth is accurately determined, wasteful water and detergent are used and the remaining time display is erroneously displayed, which causes a problem that it is different from the actual drying end time.

  The present invention solves the above-described conventional problem, and detects a signal from an acceleration sensor attached to the water tank in a section in which the rotation speed of N2 after the first detection step is maintained for ts, Rotating at a relatively low speed because the acceleration detection unit detects acceleration in the longitudinal direction of the aquarium, acceleration in the vertical direction or acceleration in the horizontal direction, and further calculates the displacement amount in the lateral, longitudinal, and vertical directions of the aquarium with the displacement detection unit. To provide a washing machine with a cloth leveling means that can accurately detect the displacement of a water tank regardless of the amount of kinetic energy in a region with simple four arithmetic operations, and can accurately detect the amount of water, amount of detergent, and remaining time during washing. Is.

  In order to solve the above-described problems, a washing machine of the present invention has a central axis of rotation in a horizontal direction or an inclination direction, and includes a drum that accommodates laundry, the drum being rotatably included, and elastic in the washing machine body. A water tank supported by the motor, 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; And the control unit accelerates the rotation of the drum by generating a predetermined acceleration torque in the motor in order to detect the amount of cloth, which is the amount of laundry, from a predetermined number of rotations N1. After the first detection step of measuring the acceleration angular acceleration α1 while the rotation speed increases to N2, and after the first detection step, and further performing control to maintain the rotation speed of N2, the motor is predetermined. Constant deceleration torque of And having a second detection step of measuring angular acceleration α2 during deceleration while the number of rotations of the drum decreases from N3 to N4, and detecting the acceleration of the water tank by the acceleration detection unit, If it is larger than the set reference value, it is determined as abnormal vibration and the motor is immediately stopped, and if it is not determined as abnormal vibration, based on the acceleration angular acceleration α1 and the deceleration angular acceleration α2, Detect the amount of cloth. Since the amount of cloth is measured using both the rise and fall speeds of the drum rotation, variations in the friction torque of the drum rotation shaft can be offset and the influence of the variations can be suppressed. The amount of cloth can be detected with high accuracy.

A drum having a central axis of rotation in a horizontal direction or an inclined direction and accommodating a laundry to perform a rotational movement; a water tank that rotatably includes the drum and elastically supported in a washing machine body; and the water tank An acceleration sensor capable of detecting vibration components in a plurality of directions fixed to the motor, an acceleration detection unit for detecting an acceleration output from the acceleration sensor, a motor for rotationally driving the drum, and a rotational speed detection for detecting the rotational speed of the motor. A control unit that controls rotation of the motor based on the detection output of the rotation speed detection unit and controls a series of processes such as cloth amount detection, washing, rinsing, and dehydration, and transmission and reception of control signals to and from the control unit And an input setting means and a display means, and the control unit generates a predetermined constant acceleration torque to the motor in the cloth amount detection step, and increases the rotation speed of the drum from N1 to N2. After the first detection step for measuring the angular acceleration α1 during acceleration and the control for maintaining the rotation speed of N2 after the first detection step, a predetermined constant deceleration torque is applied to the motor. And a second detection step of measuring the deceleration angular acceleration α2 while the rotation speed is reduced from N3 to N4, and detecting the acceleration of the water tank by the acceleration detection unit, If it is larger than the set reference value, it is determined as abnormal vibration and the motor is immediately stopped, and if it is not determined as abnormal vibration, based on the acceleration angular acceleration α1 and the deceleration angular acceleration α2, By detecting the amount of cloth, according to the washing machine configured as described above, the amount of cloth is measured using both the rising and falling speeds of the rotation of the drum, so that the variation in the friction torque of the drum rotation shaft is offset, That variation The amount of cloth can be accurately detected with a simple configuration.

  According to the washing machine configured as described above, since the amount of cloth is measured using both the drum rotation rise and descent speeds, the variation in the friction torque of the drum rotation shaft is offset and the influence of the variation can be suppressed. This is possible, and the amount of cloth can be accurately detected with a simple configuration.

  Even when the laundry in the drum is in a non-uniform state, after the first detection step, the speed is controlled and the rotation speed of N2 is maintained for ts seconds, and then an algorithm that generates a predetermined constant deceleration torque is used. Therefore, there is little vibration variation of the drum, and the repeatability of detection can be improved.

  Further, when the laundry in the drum becomes unbalanced and the vibration of the drum becomes larger than a predetermined value and abnormally vibrates, the vibration of the drum is output from the acceleration sensor, and the acceleration output is detected by the acceleration detection unit. If it is larger than the threshold value, the motor is immediately stopped, so that there is no abnormal drum vibration or the like, and the cloth amount detection step can be completed.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the drum type washing machine of the invention will be described with reference to the drawings. It should be understood that the embodiments disclosed below are illustrative in all respects and are not restrictive.

The present invention includes a rotation center shaft in a horizontal direction or an inclination direction, a drum that accommodates laundry and performs a rotational motion, and includes the drum rotatably and elastically supported in a swingable manner in a washing machine body. A water tank, an acceleration sensor that can detect vibration components in a plurality of directions fixed to the water tank, an acceleration detection unit that detects an acceleration output of the acceleration sensor, a motor that rotationally drives the drum, and a rotational speed of the motor. A rotation speed detection unit to detect, a control unit that controls rotation of the motor based on a detection output of the rotation speed detection unit, and controls a series of processes such as washing, rinsing, and dehydration; the control unit and a control signal; The control unit generates a predetermined constant acceleration torque to the motor in the cloth amount detection step, accelerates the rotation of the drum, and vibrates a water tank or the like. A first detection step of measuring an angular velocity α1 during acceleration between the rotational speed N1 and N2 below the first resonance frequency of the first and a control for maintaining the rotational speed of N2 for ts after the first detection step And a second detection step of generating a predetermined constant deceleration torque in the motor in the previous period and measuring the deceleration angular acceleration α2 while the rotation speed of the drum in the previous period decreases from N3 to N4. A signal from an acceleration sensor attached to the water tank in the first detection step is detected, and the acceleration sensor detects the maximum acceleration in the front-rear direction or the maximum acceleration in the vertical direction or the maximum speed in the left-right direction of the water tank, If it is larger than the preset reference value, it is determined as abnormal vibration during the cloth amount detection operation, and the motor is immediately stopped. In a section in which the rotation speed of N2 after the first detection step is maintained for ts, a signal from an acceleration sensor attached to the water tank is detected, and the longitudinal acceleration or vertical acceleration or horizontal direction of the water tank is detected. The acceleration detection unit detects the acceleration of the water tank, and further calculates the displacement by the displacement detection unit, so that the displacement of the aquarium can be accurately detected regardless of the magnitude of the kinetic energy in a relatively low speed rotation region. If it is larger than the reference value, it is determined that there is an abnormal vibration during the cloth amount detection operation, and the motor is immediately stopped. Therefore, the water tank does not hit the washing machine body, so that no abnormal vibration or noise is generated. If it is not determined to be abnormal, the cloth amount can be detected based on the angular velocity α1 during the previous acceleration and the respective velocity α2 during the previous deceleration.

(Embodiment 1)
FIG. 1 is a block diagram of a control circuit of the drum type washing machine, FIG. 2 is a diagram showing an operation of detecting the amount of cloth of the drum type washing machine, and FIG. FIG. 4 is a flowchart showing the cloth amount detection method, FIG. 5 is a view showing the amount and time of the cloth amount, FIG. 6 is a cross-sectional view showing a schematic configuration of the drum type washing machine, and FIG. FIG. 8 is a cross-sectional view of the vector control block diagram in quantity detection, and FIG.

  In FIG. 6, a water tank unit 76 rotatably houses a drum 78 in a water tank 82, and supports a rotating shaft 79 of the drum 78 with a bearing 80 provided on the back surface of the water tank 82, and a drum on the rotating shaft 79. A drive motor 81 is connected.

  The aquarium unit 76 is disposed with its axis inclined in the washing machine main body 83, and its weight is supported by a damping anti-vibration damper 70 attached to the base 73 of the washing machine main body 83. The first anti-vibration spring 71 and the second anti-vibration spring 72 between the back surface 86 of the washing machine body 83 are rocked between the upper support fitting 75 fixed to the upper surface of the washing machine body 83 and the upper surface of the washing machine body 83. It is supported in an elastic and vibration-proof manner.

  A door 87 is pivotally supported on the left inclined surface of the washing machine main body 83 so that the door 87 can be opened and closed, and the user puts laundry clothes into the drum 78 from the door 87 portion.

  The control unit 31 composed of a microcomputer or the like for controlling a series of processes such as washing, rinsing and dehydration of the washing machine is provided on the input setting means 25 and the display means 40 arranged above the door 87 and on the upper outer wall of the water tank 82. Signals are transmitted to the fixed acceleration sensor 38 and rotation control of the motor 81 and the like is performed.

  The acceleration sensor 38 is composed of, for example, a semiconductor acceleration sensor, and is composed of a multi-axis (two-axis or three-axis) direction acceleration sensor such as front / rear / left / right / up / down instead of unidirectional acceleration. This is because the vibration of the actual aquarium unit 76 is not necessarily limited to one direction, so that a highly accurate movement of the aquarium 82 is detected using a multi-axis acceleration sensor.

  In the block configuration diagram of the control circuit of FIG. 1, the inverter circuit 24 uses the DC power that is rectified by the rectifier 21 and smoothed by the smoothing circuit including the choke coil 22 and the smoothing capacitor 23 as the driving power. Thus, the motor 81 is rotationally driven.

  Further, the control unit 31 controls the rotation of the motor 81 based on the driving instruction input from the input setting unit 25 and the monitoring information of the driving state detected by each detecting unit (not shown), and the load driving unit 26 controls the operations of the water supply valve 27, the drain valve 28, the blower fan 12, and the heater 29, and the display means 40 transmits a display signal so that the user can know the operation state and the control state.

The motor 81 includes a stator having three-phase windings 7a, 7b, and 7c and a rotor (not shown) having two-pole permanent magnets, and is provided with three position detection elements 30a, 30b, and 30c. The rotation is controlled by a PWM control inverter circuit 24 configured as a motor and configured by 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 or the like. Based on this rotor position detection signal, the drive circuit 32 performs PWM control of the on / off states of the switching elements 24a to 24f, thereby controlling the energization of the three-phase windings 7a, 7b, and 7c of the stator to control the motor 81. Rotate at the required speed.

  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 includes the three position detection elements 30a, 30b, and 30c. The period is detected according to the change in the state of any signal, and the rotation speed of the motor 81 is calculated from the period.

  Since the load applied to the motor 81 fluctuates according to the amount of clothes put in the drum 78, if the detection output of the rotation speed detection unit 33 is supplied to the cloth amount detection unit 34, it is based on the detected number of rotations. The amount of cloth thrown into the drum 78 is detected.

  Since the detection output of the rotation speed detection unit 33 of the motor 81 corresponds to the rotation number in the drum 78, the rotation number of the water tank 82 is obtained from the detection output of the rotation speed detection unit 33 in the following description. .

  The acceleration sensor 88 fixed to the water tank 82 detects at least acceleration in a plurality of directions before and after the water tank, and the acceleration detection unit 39 configured in the control unit 31 receives a digital signal or an analog signal from the acceleration sensor 88. In a section in which the rotation speed of N2 after at least the first detection step is maintained for ts, a signal from an acceleration sensor attached to the water tank is detected, and a longitudinal acceleration or a vertical acceleration of the water tank or By detecting the acceleration in the left-right direction with the acceleration detector and further calculating the displacement with the displacement detector 40, the displacement of the aquarium can be accurately calculated regardless of the magnitude of the kinetic energy in the relatively low speed rotation region. Detect the presence or absence of abnormal vibration.

  The reason why the speed control unit 36 maintains the N2 rotational speed for ts seconds is that the inertia moment of the vibration system such as the drum changes due to the amount of clothes put into the drum 78, and the overshoot amount of the rotational speed changes greatly. For example, if the rotation speed further increases, the rotation unevenness of the drum 78 increases as the rotation frequency of the drum 78 approaches the resonance frequency of the main body, and the inertia in the first detection process is accelerated from N1 to N2 with a constant torque. It will be in a different state. Immediately in this state, when a predetermined deceleration torque T2 is generated and the time t2 is measured from N3 to N4, that is, the second detection step, the detection error is large and the cloth amount detection accuracy is deteriorated. Therefore, by controlling the speed of the motor 81 by the speed control unit 36, maintaining the N2 rotation speed for ts seconds makes it unaffected by the amount of clothing, so that the detection accuracy can be improved. Further, the acceleration data detected by the acceleration detection unit 39 during the period in which the N2 rotational speed is maintained can be accurately calculated by the displacement detection unit 40 by simple four arithmetic operations.

  From Equation 20, when the rotational speed ω is constant, if the acceleration is known, the displacement of the water tank 82 can be obtained instantaneously with a simple calculation.

  The cloth amount detection method in the present embodiment will be described below with reference to FIG.

  FIG. 2 is a diagram illustrating an operation of detecting the cloth amount, where the horizontal axis indicates the elapsed time from the start of the cloth amount detection, and the vertical axis indicates the rotation speed of the motor 81, that is, the drum 78.

  When the controller 31 instructs the start of the cloth amount detection process before the start of the washing operation, the motor 81 starts to rotate, and after the predetermined time has elapsed or the predetermined rotational speed N1 is reached, the motor 81 causes the acceleration torque T1. And a first detection step is performed in which the rotational speed is increased by ΔN1 and reaches a predetermined rotational speed N2 during time t1.

  Here, the predetermined rotational speed N1 is a low-speed rotational speed immediately after the start of the motor 81, and the predetermined rotational speed N2 is a rotational speed equal to or lower than the primary resonance frequency of the water tank 82 which is the vibration system in FIG. It is. As soon as the rotation speed of the motor 81 reaches N2 from N1 by the acceleration / deceleration torque control unit 35, the speed control 36 controls to maintain the rotation speed of N2 for a period of ts without reducing the rotation speed, and the N2 rotation speed is reduced. The acceleration sensor 38 detects the longitudinal acceleration, the vertical acceleration, or the horizontal acceleration of the water tank 82 with the acceleration detection unit, and further calculates the displacement with the displacement detection unit 40. Thus, the displacement of the aquarium can be accurately detected regardless of the magnitude of the kinetic energy in the relatively low speed rotation region, and if the displacement amount is large by comparing the preset value with the displacement amount of the aquarium, the control unit 31 will abnormally vibrate. And the motor 81 is stopped by a command from the motor control unit 31. If the amount of displacement is smaller than the predetermined value, it is determined that there is no abnormal vibration, the motor 81 is turned to deceleration, and the acceleration / deceleration torque control unit 35 generates the deceleration torque T2 by the inertialy rotated motor 81, and the time During t2, a second detection step is performed in which the rotational speed is decreased by ΔN2 from the predetermined rotational speed N3 to reach the predetermined rotational speed N4.

  The cloth amount detection is determined in advance by the cloth amount detection unit 34 based on the load generated in the motor 81 when the rotation speed is increased in the first detection process and the decrease speed of the rotation speed due to inertia in the second detection process. Is set based on the specified table.

  FIG. 4 is a flowchart showing the cloth amount detection method in the present embodiment. When the cloth amount detection starts (S30), the drum abnormal vibration control unit 31 drives the motor 7 to reach the predetermined rotation speed N1 (S32), and increases the rotation speed of the drum 78 by a predetermined torque. (S33), control is performed so that the rotation speed reaches a predetermined rotation speed N2 increased by ΔN1 (S32). When the drum 78 reaches the rotational speed N2 (S34), a time t1 required for the rotational speed to increase by ΔN1 is calculated (S35).

  Next, speed control is performed so as to maintain the rotation speed of the motor 81 at N2 (S36). The rotation speed of N2 is maintained for ts seconds (S37), and the drum 78 is lowered by inertial rotation (S38). When the drum 78 reaches N3, a predetermined deceleration torque is applied (S40), and when the drum 78 reaches a predetermined rotation speed N4 from the predetermined rotation speed N3 to N4 by a section ΔN2, the rotation speed is reached (S41). The required time t2 required for the number to drop by ΔN2 is calculated (S42). Next, a difference α1-α2 of angular acceleration is obtained from ΔN1, t1, ΔN2, t2 based on Equation 5 and Equation 7 (S43), and Equation 9 is obtained from the relationship between the determination value S and the cloth amount measured in advance. The amount of cloth is obtained based on (S44).

  In order to accurately detect the amount of cloth using Equation 9, it is desirable to control the acceleration torque T1 and the deceleration torque T2 of the motor 7 to be constant.

The feature of the cloth amount detection method in the present embodiment will be described with reference to FIG. FIG. 2 shows the relationship between the time required for increasing the rotational speed of the drum 3 and the time required for decreasing the rotational speed. The horizontal axis represents the elapsed time from the start of the cloth amount detection, and the vertical axis represents the rotation speed. When the cloth amount detection is started, after a predetermined time has elapsed or the rotation speed has been reached, an acceleration torque T1 is generated by the motor 7, and a first detection process is performed in which the rotation speed is increased by ΔN1 during the time t1. After the first detection step is completed, the rotation speed of the drum 3 is changed from acceleration to deceleration, and then the motor 7 generates a deceleration torque T2, and the rotation speed is decreased by ΔN2 during the time t2. Two detection steps are performed.

  Here, the operation state of the first detection process will be considered.

  From Equation 3 described in Background Art, angular acceleration α1 in the first detection step is represented by Equation 5.

  From Equation 3, Equation 6 is established.

  Similarly, considering the second detection step, Equation 7 and Equation 8 are obtained when the angular acceleration in the second detection step is α2.

  When the component of the friction torque Tb is eliminated from Equation 6 and Equation 8, Equation 9 is obtained.

  When the average radius r, acceleration torque T1, and deceleration torque T2 on the drum inner circumference of the cloth are constant values, the numerical formula 9 is (α1-α2) according to the weight m of the cloth as shown in FIG. Indicates a change.

  Here, α1 and α2 can be easily obtained by measuring the relationship between the number of rotations of the drum 3 and time, as shown in Equations 5 and 7.

  In addition, when the torque is controlled from N1 to N2 at a constant torque and free run is performed when the rotation speed reaches N2, the inertia changes depending on the amount of laundry, and the higher the drum inertia moment, the faster the speed after the rotation speed is reached. The amount of overshoot increases. Even if the inertia changes depending on the amount of laundry, the speed is controlled at N2, and an algorithm that generates a constant deceleration torque after maintaining N2 is always used regardless of the amount of laundry. Therefore, it is possible to generate a deceleration torque and measure t2 to calculate α2, so that detection variation can be suppressed and detection accuracy can be improved.

Therefore, only the relationship between the fabric weight m and the change in the angular acceleration (α1−α2) is grasped and stored as a table or the like in the fabric amount detection unit 34 in FIG. 1, regardless of the change in the friction torque Tb. It can be seen that the amount of cloth can be detected easily and accurately.

  Such control can be realized by controlling the voltage applied to the motor 7, but it is generally known that constant torque control of the motor is performed by vector control as shown in FIG. .

  In the control block of FIG. 7, at least a two-phase current out of the current supplied to the motor 7 and a rotational position signal of the motor obtained by a Hall IC or the like are detected. Using these signals, the current of the motor 7 is converted into two orthogonal currents, Iq which is a torque component and Id which is a magnetic flux component. Thereafter, by comparing the converted Iq and Id with the commanded Iq * and Id * and using appropriate control gains P and I, the motor 7 can be controlled to be constant Iq and Id. .

  Here, since the torque T of the motor 7 is expressed by Equation 10, the torque T of the motor 7 can be controlled by controlling Iq and Id.

  Here, P is the number of pole pairs of the motor 7, ψa is a flux linkage by a magnet, Ld is a d-axis inductance, and Lq is a q-axis inductance.

  In particular, ψa · Iq in Equation 10 represents the magnet torque and is the main component of the torque generated by the motor. Therefore, the torque of the motor 7 can be controlled by Iq. Further, when Id is not zero, if Ld or Lq changes depending on the rotation state, an error is likely to occur when calculating the torque T when calculating the variation of the torque T or the amount of cloth. In other words, there is a case where the torque T does not become constant even if Iq and Id are controlled to be constant. Therefore, by setting Id to zero and controlling the torque of the motor 7 to be constant by controlling Iq to be constant, It is desirable to reduce the calculation error.

  ADVANTAGE OF THE INVENTION According to this invention, it is possible to detect the quantity of cloth thrown into the drum accurately with a simple configuration and perform a good dehydration process, and it is useful for household and commercial washing machines.

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 operation | movement of the cloth amount detection used for the drum type washing machine The figure which shows the cloth amount and acceleration difference of the cloth amount detection Flow chart showing the cloth amount detection method Vector control block diagram for the same cloth amount detection The figure which shows the control method of the drum type washing machine Sectional drawing which shows schematic structure of a drum type washing machine The figure which shows the cloth amount detection method of the drum type washing machine of a prior art example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Washing machine main body 2 Water tank 3 Drum 4 Clothes entrance / exit 5 Door 6 Through-hole 7 Motor 7a, 7b, 7c Three-phase winding 8 Water injection pipe 9 Drain pipe 10 Operation panel 11 Circulation ventilation path 12 Blower fan 13 Filter 14 Rotation detection Unit 20 Commercial power supply 21 Rectifier 22 Choke coil 23 Smoothing capacitor 24 Inverter circuit 24a to 24f Switching element 25 Input setting unit 26 Load drive unit 27 Water supply valve 28 Drain valve 29 Heater 30a, 30b, 30c Position detection element 31 Control unit 32 Drive circuit 33 Rotation speed detection unit 34 Cloth amount detection unit

Claims (1)

A drum having a central axis of rotation in a horizontal direction or an inclined direction and accommodating a laundry to perform a rotational movement; a water tank that rotatably includes the drum and elastically supported in a washing machine body; and the water tank An acceleration sensor capable of detecting vibration components in a plurality of directions fixed to the motor, an acceleration detection unit for detecting an acceleration output from the acceleration sensor, a motor for rotationally driving the drum, and a rotational speed detection for detecting the rotational speed of the motor. A control unit that controls rotation of the motor based on a detection output of the rotation speed detection unit, and controls a series of processes such as cloth amount detection, washing, rinsing, dehydration, and the like. The controller includes an input setting unit and a display unit for performing transmission and reception, and the control unit generates a predetermined constant acceleration torque to the motor in the cloth amount detection step, and increases the rotation speed of the drum from N1 to N2. After the first detection step of measuring the angular acceleration α1 during acceleration and after the first detection step, the control for maintaining the rotation speed of N2 is further performed, and then the motor is subjected to a predetermined constant deceleration torque. And detecting a deceleration angular acceleration α2 while the rotational speed is decreasing from the rotational speed N3 to N4 of the drum, and detecting the acceleration of the water tank by the acceleration detecting unit, If it is larger than the preset reference value, it is determined as abnormal vibration and the motor is immediately stopped, and when it is not determined as abnormal vibration, based on the acceleration angular acceleration α1 and the deceleration angular acceleration α2, A washing machine that detects the amount of cloth.

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