JP2018126337A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a washing machine which suppresses excessive increase in a motor temperature and which can acquire high washing performance.SOLUTION: A washing machine includes: a motor 14; a motor temperature measurement part for measuring the temperature of the motor 14; and a control part 54 for executing a washing operation by agitating laundry together with washing water by performing drive control of the motor 14. The control part 54 includes: an estimation part for estimating a reaching temperature Te from the temperature of the motor 14 which the motor temperature measurement part has measured a plurality of times with a time interval; and a water flow setting part for changing a water flow generated by the rotation of the motor 14 according to the reaching temperature Te estimated by the estimation part.SELECTED DRAWING: Figure 3

Description

  Embodiments described herein relate generally to a washing machine.

  The washing machine executes a washing operation by agitating the laundry accommodated in the rotating tub together with the washing water as the motor rotates the rotating tub and the stirring body. In this motor, the motor is cooled by a cooling fan provided in the rotor. However, in a washing operation that rotates at a low speed, the cooling fan provided on the rotor also rotates at a low speed, so that the motor is difficult to cool and the motor temperature tends to rise. For this reason, if the washing operation is continued for a long time, or if the washing operation is executed in a state where more than expected laundry is put in the rotating tub, the motor temperature may rise excessively and the motor may be damaged.

  Therefore, when the current supplied to the motor during the washing operation exceeds a predetermined threshold, the motor is stopped and the temperature rise of the motor may be suppressed. In such a case, the washing operation is interrupted. Cleaning performance is significantly reduced.

  Further, in Patent Document 1 below, it is proposed that the temperature of the motor winding is measured, and the temperature increase of the motor is suppressed by switching the rotation speed of the rotating tub based on the measured temperature. However, in Patent Document 1 below, since the switching of the rotation speed of the rotating tub is controlled by comparing the measured temperature with a predetermined set temperature, appropriate temperature control becomes difficult depending on the temperature change rate. In other words, if the temperature change is steep, the switching of the rotation speed may be delayed and the temperature may rise excessively. If the temperature change is slow, the switching of the rotation speed becomes faster, and the rotation speed is unnecessarily reduced. Cleaning performance may be reduced.

Japanese Patent Laid-Open No. 11-137848

  Then, it aims at providing the washing machine which can acquire the high washing | cleaning performance while suppressing the excessive raise of motor temperature.

  The washing machine according to the embodiment includes a motor, a control unit that controls the motor, a motor temperature measurement unit that measures the temperature of the motor, and driving and controlling the motor to agitate the laundry together with the washing water to wash In the washing machine including the control unit that performs the operation, the control unit reaches the motor that the motor temperature measurement unit reaches during the washing operation from the temperature of the motor measured a plurality of times at intervals. An estimation unit that estimates temperature, and a water flow setting unit that changes a water flow generated by rotation of the motor according to the reached temperature estimated by the estimation unit.

The block diagram which shows the electric constitution of the motor provided in the washing machine concerning 1st embodiment. The vertical side view of the washing machine concerning a first embodiment. The flowchart which shows the control content of washing operation. The figure which shows an example of the water flow which can be set in a washing operation.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  The washing machine of this embodiment is a drum-type washing machine provided with a drum that is arranged as a rotating tub as shown in FIG. In the present embodiment, a drum-type washing machine will be described as an example of a washing machine. However, a washing machine including a vertical-type rotating tub may be used.

  In this washing machine, a door 2 is provided at the center and an operation panel 3 is provided at the top of the front surface of the outer box 1 that forms the outer shell. The door 2 opens and closes a laundry entry / exit 4 formed in the center of the front portion of the outer box 1.

  A cylindrical water tank 5 is disposed inside the outer box 1. The water tank 5 is disposed in a horizontal axis shape in which the axial direction is the front-rear direction (left-right direction in FIG. 2) and in an upwardly inclined shape, and is elastically supported by the elastic support device 6. Inside the water tank 5, a cylindrical rotating tank (drum) 7 is disposed coaxially with the water tank 5. The drum 7 functions as a shared tank for washing and dehydration and drying. A large number of small holes 8 are formed in almost the entire region of the body, and a plurality of baffles 9 are provided on the inner periphery of the body. ing.

  The water tub 5 and the drum 7 have openings 10 and 11 for putting in and out the laundry on their front parts, and the opening 10 of the water tub 5 is connected to the laundry entry and exit 4 in a watertight manner by a bellows 12, The opening 11 of the drum 7 faces the opening 10 of the water tank 5.

  The water tank 5 is supplied with water such as tap water from the outside of the water supply port 21 provided at the upper part of the water tank 5 through the water supply valve 20, and the drain valve 23 is provided from the drain port 22 provided at the bottom of the water tank 5. It is comprised so that the water in the water tank 5 can be drained out of the apparatus.

  A motor 14 that rotationally drives the drum 7 is disposed on the back surface of the water tank 5. The motor 14 is an outer rotor type DC brushless motor, and a stator 15 is attached to an outer peripheral portion of a bearing housing 16 attached to a central portion of the back portion of the water tank 5. The rotor 17 is disposed so as to cover the stator 15 from the outside, and a rotating shaft 18 attached to the center is rotatably supported by the bearing housing 16 via a bearing 19. The front end portion of the rotating shaft 18 protruding from the bearing housing 16 is connected to the central portion of the back portion of the drum 7. That is, when the rotor 17 of the motor 14 is rotated, the drum 7 is also rotated integrally with the rotor 17.

  The operation panel 3 provided in the upper front portion of the outer box 1 includes various operation buttons including a start switch and a course selection key, and a display unit that displays necessary information such as set course contents and the operating state of the washing machine.

  A control device 30 is provided on the back surface of the operation panel 3. The control device 30 includes a control unit 54 composed of a microcomputer and a memory, and controls the water supply valve 20, the motor 14 and the drain valve 23 in accordance with the operation of the operation switch of the operation panel 3, and performs washing, rinsing and dehydration. Execute washing operation.

  FIG. 1 is a block diagram showing the configuration of the control device 30. In FIG. 1, (α, β) indicate orthogonal coordinate diameters obtained by orthogonally transforming a three-phase (UVW) coordinate system with an electrical angle of 120 degrees corresponding to each of the three-phase brushless phases constituting the motor 14, (D, q) shows the coordinate system of the secondary magnetic flux rotating with the rotation of the rotor 17 of the brushless motor 14.

  The subtracter 33 shown in FIG. 1 is provided with a target speed command ωref as a subtracted value and a detected speed ω that is the rotational speed of the motor 14 detected by an estimator 34 as a subtracted value. The target speed command ωref is output from the control unit 54 that controls the overall operation of the washing machine. The subtraction result of the subtracter 33 is given to a speed PI control unit (speed control means) 35.

  The speed PI control unit 35 performs PI control based on a difference amount between the target speed command ωref and the detected speed ω, and generates a q-axis current command value Iqref and a d-axis current command value Idref. The subtracters 36 and 37 subtract the results of subtraction between the command values Iqref and Idref generated by the speed PI control unit 35 and the q-axis current value Iq and d-axis current value Id output from the αβ / dq conversion unit 38 from the current PI control. Output to the sections 39q and 39d. The q-axis current value Iq and the d-axis current value Id are also given to the control unit 54.

  The current PI control units 39q and 39d perform PI control based on the difference between the q-axis current command value Iqref and the d-axis current command value Idref, and generate the q-axis voltage command value Vq and the d-axis voltage command value Vd. Output. The dq / αβ conversion unit 40 converts the voltage command values Vd and Vq into voltage command values Vα and Vβ based on the rotational phase angle (rotor position angle) θ of the secondary magnetic flux in the motor 14 detected by the estimator 34. To do.

  The αβ / UVW conversion unit 41 converts the voltage command values Vα and Vβ into three-phase voltage command values Vu, Vv, and Vw and outputs them. The changeover switches 42u, 42v, and 42w switch the voltage command values Vu, Vv, and Vw and the voltage command values Vus, Vvs, and Vws for activation output from the initial pattern output unit 43 and output them.

  The PWM forming unit 44 supplies each phase PWM signal Vup (+, −), Vvp (+, −), Vwp (+, −) obtained by modulating a 16 kHz carrier wave based on the voltage command values Vus, Vvs, Vws to the power supply module 50. Output to.

  The power supply module 50 includes an inverter circuit 45 and a drive circuit 51, and a PWM signal output from the PWM forming unit 44 is input to the inverter circuit 45 via the drive circuit 51. The inverter circuit 45 constituting the power supply module 50 is configured by connecting six IGBTs 46 in a three-phase bridge, and the emitters of the lower arm side U and V phase IGBTs 46 are current detecting shunt resistors (current detecting means). It is connected to the ground via 47 (u, v). The common connection point between the two is connected to the A / D converter 49 via an amplification / bias circuit (not shown). The inverter circuit 45 is applied with a DC voltage of about 280V obtained by double voltage full-wave rectification of a 100V AC power supply. The amplifier / bias circuit amplifies the terminal voltage of the shunt resistor 47 and applies a bias so that the output range of the amplified signal is within the positive side.

  The A / D converter 49 outputs current data Iu and Iv obtained by A / D converting the output signal of the amplifier / bias circuit. The UVW / αβ converter 52 estimates W-phase current data Iw from the current data Iu, Iv, and converts the three-phase current data Iu, Iv, Iw into biaxial current data Iα, Iβ in an orthogonal coordinate system.

  The αβ / dq conversion unit 38 obtains the rotor position angle θ of the motor 14 from the estimator 34 during vector control, converts the biaxial current data Iα, Iβ into the d-axis current value Id, the q-axis current value Iq, and the conversion result Is output every predetermined time (for example, every 128 μsec). The estimator 34 estimates the position angle θ and the rotational speed ω of the rotor 17 based on the d-axis current value Id and the q-axis current value Iq, and outputs them to the subtractor 33 and the control unit 54.

  The control unit 54 controls operations of the water supply valve 20, the drain valve 23, the motor 14, and the like. In addition, the control unit 54 measures the temperature of the motor 14 (hereinafter, may be referred to as “motor temperature”), and the motor 14 that arrives within the execution time of the washing operation from the measured temperature of the motor 14. It also functions as an estimation unit that estimates temperature (hereinafter may be referred to as reached temperature) and a water flow setting unit that changes the setting of the water flow in the washing operation based on the estimated reached temperature.

  In the above configuration, the configuration excluding the power supply module 50 is realized mainly by software of a DSP (Digital Signal Processor) 53.

  Next, the washing operation of the washing machine of this embodiment will be described. FIG. 3 is a flowchart showing the control contents of the laundry put into the drum 7 during the washing operation, and is executed by the control unit 54 provided in the control device 30.

  When the user sets a washing course from an operation button provided on the operation panel 3 and instructs to start operation, the washing machine starts a washing operation according to the set washing course.

  When the washing operation is started, the control unit 54 detects the weight of the stored laundry by driving the motor 14 and rotating the drum 7 in step S1, and proceeds to step S2.

  In step S2, the control unit 54 sets washing conditions such as a water level and a washing time based on the weight of the clothing detected in step S1, and proceeds to step S3.

  In step S3, the control unit 54 opens the water supply valve 20 while keeping the drain valve 23 closed, and supplies the washing water into the water tank 5 until the water level set in step S2 is reached.

  When the supply of the washing water to the aquarium 5 is completed, the process proceeds to step S4, and the control unit 54 drives the motor 14 to rotate the drum 7 alternately in both forward and reverse directions at a low speed, and the washing time set in step S2 The laundry is agitated together with the washing water in the drum 7 until the time elapses, and the washing operation (washing process) is executed.

  When the washing operation is started, the control unit 54 performs initial temperature measurement for measuring the motor temperature a plurality of times every predetermined time (step S5). For example, in the initial temperature measurement, the control unit 54 measures the motor temperature immediately after the start of the washing operation, then measures the motor temperature twice every 30 seconds, and the initial temperature measurement measures the motor temperature three times in total. taking measurement.

  As a method for the control unit 54 to measure the motor temperature, for example, the winding temperature of the stator 15 of the motor 14 is measured based on the d-axis current value Id output from the αβ / dq conversion unit 38, or the stator 15 A temperature sensor is provided at a predetermined location of the motor 14 such as a winding of the motor 14 to measure the temperature of the motor 14, or the temperature of the power supply module 50 provided in the control device 30 is measured by the temperature sensor, and the measured temperature is measured as the motor temperature. can do.

  When the initial temperature measurement is completed, the process proceeds to step S6, and the control unit 54 estimates the reached temperature reached by the motor 14 during the washing operation based on the motor temperature measured in the initial temperature measurement.

As an example of the method of estimating the reached temperature, when the elapsed time from the start of the washing operation is X and the measured motor temperature is T, the motor temperature T with respect to the elapsed time X is an estimation function of the following formula (1). The coefficient (a, b) of the following equation (1) is calculated from the data sequence of the elapsed time X and the motor temperature T obtained in the initial temperature measurement of step S5 using the multidimensional least square method. Obtain an estimation function for estimating the motor temperature T.
T = a · ln (X) + b Formula (1)
And the control part 54 substitutes the washing time set by step S2 to the estimation function which estimates the obtained motor temperature T, and the ultimate temperature which the motor 14 reaches | attains during execution of a washing operation based on an estimation function Te is calculated (step S6).

  In step S7, the control unit 54 changes the setting of the water flow in the washing operation based on the reached temperature Te calculated in step S6. Specifically, in the present embodiment, the control unit 54 sets the water flow condition so that the strength of the water flow in the washing operation becomes weaker as the reached temperature Te calculated in step S6 becomes higher.

  For example, the controller 54 stores a plurality of types of water flow conditions as shown in FIG. 4 in association with the ultimate temperature Te, and selects the water flow conditions corresponding to the ultimate temperature Te calculated in step S6. Then, by controlling the rotation of the motor 14 according to the selected condition, the water flow condition is set so that the strength gradually decreases as the ultimate temperature Te increases.

  In the case of FIG. 4, if the reached temperature Te calculated in step S <b> 6 is less than 80 ° C., the control unit 54 sets the drum 7 to turn on when the drum 7 is rotated in the ON time for rotating the drum 7 for 5 seconds. Set OFF time to pause for 0 seconds. Further, the controller 54 sets the ON time and OFF time to 5 seconds and 1 second when the ultimate temperature Te is 80 ° C. or higher and lower than 100 ° C., and the ON time when the ultimate temperature Te is 100 ° C. or higher and lower than 120 ° C. The OFF time is set to 5 seconds and 3 seconds, and the ON time and OFF time are set to 5 seconds and 5 seconds when the ultimate temperature Te is 120 ° C. or higher. The maximum number of rotations of the drum 7 is set to 50 rpm at any ultimate temperature Te.

  In addition to changing the OFF time as described above, the change of the water flow condition is, for example, decreasing the maximum rotation speed to weaken the strength of the water flow, shortening the ON time to reduce the strength of the water flow, You may change so that the intensity | strength of a water flow may be weakened combining these.

  In step S8, the control unit 54 determines whether or not the washing time set in step S2 for the washing process has elapsed. If the washing time has elapsed, the washing operation is terminated, and if the washing time has not elapsed, the process proceeds to step S9. .

  In step S9, the control unit 54 determines whether or not a predetermined time (hereinafter may be referred to as a measurement time) has elapsed since the previous measurement of the motor temperature. If the measurement time has elapsed, the control unit 54 proceeds to step S10. Measure motor temperature. The measurement time can be set to 30 seconds, for example.

  When the measurement of the motor temperature is completed in step S10, the control unit 54 proceeds to step S11, and adds the data obtained in step S11 to the data sequence of elapsed time X and motor temperature T obtained after starting the washing operation. The coefficient (a, b) of the above equation (1) is obtained from the data string using the multidimensional least square method, and the estimation function for estimating the motor temperature T is updated. And the control part 54 calculates again the ultimate temperature Te of the motor 14 which reaches | attains within the washing time set by step S2 based on the updated function, and updates the ultimate temperature Te (step S11).

  And if the control part 54 updates the reached temperature Te, it will return to step S7 and will change the setting of the water flow in a washing operation based on the updated reached temperature Te.

  Hereinafter, the control unit 54 measures the motor temperature (step S10) every time the measurement time elapses until the washing time set in step S2 elapses (step S9), and obtains the data obtained every time the measurement is performed. In addition to the data sequence of the elapsed time X and the motor temperature T acquired from the start of the washing operation, the estimation function for estimating the motor temperature T and the arrival temperature Te are updated based on the added data sequence (step S11), and the updated arrival The setting of the water flow is changed based on the temperature Te (step S7) is repeated.

  And if the washing time set by step S2 passes (Yes of step S8), the control part 54 will complete | finish washing operation, and will transfer to dehydration operation.

  In the washing machine of the present embodiment, the arrival temperature Te is estimated from the motor temperature measured a plurality of times at intervals, and the rotation of the motor 14 is controlled so as to change the water flow according to the estimated arrival temperature Te. Appropriate rotation control according to the temperature change is possible, and the motor 14 is prevented from being excessively suppressed to prevent the motor 14 from being damaged by excessively suppressing the operation of the motor 14 and reducing the cleaning performance more than necessary. be able to.

  Moreover, in this embodiment, even after changing the rotation control of the motor 14 from the reached temperature Te estimated by the control unit 54 based on the initial temperature, the motor temperature is measured every time the measurement time elapses and measured so far. Since the reached temperature Te is calculated again together with the motor temperature and updated, the rotation control can be further appropriately performed according to the change in the motor temperature.

(Modification 1)
In the embodiment described above, one type of function is used as the estimation function for estimating the motor temperature, but the ultimate temperature Te may be estimated using a plurality of types of functions.
For example, according to the motor temperature measured immediately after the start of the washing operation in the initial temperature measurement, one function can be selected from a plurality of types of estimation functions, and the ultimate temperature Te can be calculated using the selected estimation functions. Further, the reached temperature Te may be calculated by changing the function for estimating the motor temperature according to the washing course set by the user from the operation button of the operation panel 3.

  By changing the function according to the motor temperature measured immediately after the start of the washing operation, the motor temperature may already be high, such as when the washing machine is operating continuously. It can be estimated, and appropriate rotation control according to the change of the motor temperature becomes possible.

  Also, depending on the washing operation course, even if there are courses in which the laundry tends to get tangled and the load increases, and the motor temperature tends to rise, and the course where the load on the motor 14 is low and the motor temperature is difficult to rise, By changing, the motor temperature can be accurately estimated, and appropriate rotation control according to the change in the motor temperature becomes possible.

(Modification 2)
In the embodiment described above, the control unit 54 calculates the ultimate temperature Te regardless of the motor temperature measured by the motor temperature measurement unit. For example, the motor temperature measured by the motor temperature measurement unit is equal to or higher than a predetermined temperature. Then, the controller 54 may stop the washing operation by stopping the motor 14 without calculating or updating the reached temperature Te. In such a case, the rotation of the motor 14 can be urgently stopped to prevent the motor 14 from being damaged.

(Other embodiments)
As mentioned above, although embodiment of this invention was described, these embodiment was shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

DESCRIPTION OF SYMBOLS 1 ... Outer box, 2 ... Door, 5 ... Water tank, 7 ... Drum, 14 ... Motor, 15 ... Stator, 16 ... Bearing housing, 17 ... Rotor, 30 ... Control apparatus, 45 ... Inverter circuit, 50 ... Power supply module, 51 ... Drive circuit, 54 ... Control part

Claims (8)

A motor,
A motor temperature measuring unit for measuring the temperature of the motor;
In a washing machine including a control unit that performs washing operation by stirring the laundry together with washing water by driving and controlling the motor,
The controller is configured to estimate an reached temperature reached by the motor during execution of a washing operation from the temperature of the motor measured by the motor temperature measurement unit a plurality of times at intervals, and the estimation unit estimates A washing machine comprising: a water flow setting unit that changes a water flow generated by rotation of the motor according to the reached temperature.   The washing machine according to claim 1, wherein the motor temperature measurement unit measures the temperature of the motor from a winding temperature of the motor.   The washing machine according to claim 2, wherein the motor temperature measurement unit measures the temperature of the motor based on a current value flowing through the motor.   The washing machine according to claim 1, wherein the motor temperature measurement unit measures the temperature of the motor from the temperature of a power supply module of the motor. The estimation unit, after estimating the reached temperature, updates the reached temperature based on the temperature of the motor measured by the motor temperature measurement unit,
The washing machine according to any one of claims 1 to 4, wherein the water flow setting unit changes the water flow based on the reached temperature updated by the estimation unit.   The said estimation part changes the estimation function for estimating the said ultimate temperature according to the temperature of the said motor which the said motor temperature measurement part measured first after the washing operation start. Washing machine.   The washing machine according to any one of claims 1 to 6, wherein the estimation unit changes an estimation function for estimating the reached temperature depending on a washing course to be executed.   The washing machine according to any one of claims 1 to 7, wherein the control unit stops the washing operation when the temperature of the motor measured by the motor temperature measurement unit is equal to or higher than a predetermined temperature.

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