CN108396507B

CN108396507B - Washing machine

Info

Publication number: CN108396507B
Application number: CN201810128222.XA
Authority: CN
Inventors: 铃木雅也
Original assignee: Toshiba Lifestyle Products and Services Corp
Current assignee: Toshiba Lifestyle Products and Services Corp
Priority date: 2017-02-08
Filing date: 2018-02-08
Publication date: 2021-02-12
Anticipated expiration: 2038-02-08
Also published as: CN108396507A; JP2018126337A

Abstract

The invention provides a washing machine, which can restrain the excessive temperature rise of a motor and obtain higher washing performance. The washing machine is provided with: a motor (14); a motor temperature measuring unit for measuring the temperature of the motor (14); and a control part (54) which performs washing operation by driving and controlling the motor (14) to stir the washing water and the washings together; the control unit (54) is provided with: an estimation unit that estimates an arrival temperature (Te) from the temperature of the motor (14) measured by the motor temperature measurement unit a plurality of times at intervals; and a water flow setting unit that changes the water flow generated by the rotation of the motor (14) according to the estimated temperature (Te) reached by the estimation unit.

Description

Washing machine

The application is based on the Japanese patent application No. 2017-21667 (application date: 2017, 2, 8) and enjoys the priority benefit of the application. This application is incorporated by reference into this application in its entirety.

Technical Field

Embodiments of the present invention relate to a washing machine.

Background

The washing machine performs a washing operation by rotating the rotary tub and the agitator by the motor to agitate laundry and washing water contained in the rotary tub. The motor is cooled by a cooling fan provided in the rotor. However, in the washing operation with the low-speed rotation, the cooling fan provided in the rotor also rotates at a low speed, so that it is difficult to cool the motor, and the motor temperature tends to increase. Therefore, when the washing operation is continued for a long time or the washing operation is performed in a state where the laundry is thrown into the spin basket beyond expectation, the temperature of the motor may excessively rise to damage the motor.

Therefore, although the temperature rise of the motor is suppressed by stopping the motor when the current supplied to the motor exceeds a prescribed threshold value in the washing operation, the washing operation may be interrupted in this case to cause a serious drop in the washing performance.

In addition, the following is proposed in Japanese patent laid-open No. 11-137884: that is, the temperature of the coil of the motor is measured, and the rotation speed of the rotary tub is switched based on the measured temperature, thereby suppressing the temperature rise of the motor. However, in japanese patent application laid-open No. 11-137884, since switching of the rotation speed of the rotary tub is controlled by comparing the measured temperature with a predetermined set temperature, it is difficult to perform appropriate temperature control according to the temperature change rate. That is, when the temperature change is rapid, the switching of the rotational speed may be delayed to cause an excessive temperature rise, and when the temperature change is slow, the switching of the rotational speed may be fast, and the rotational speed may be unnecessarily reduced to cause a reduction in the cleaning performance.

Disclosure of Invention

Technical problem to be solved by the invention

Accordingly, an object of the present invention is to provide a washing machine capable of suppressing an excessive rise in temperature of a motor and obtaining high washing performance.

Means for solving the technical problem

The washing machine of the embodiment comprises: a motor; a motor temperature measuring unit for measuring the temperature of the motor; and a control part for performing washing operation by driving and controlling the motor to stir the washing water and the washing together; the control unit includes: an estimating part for estimating the reaching temperature of the motor in the executing process of the washing operation according to the temperature of the motor measured by the motor temperature measuring part for a plurality of times at intervals; and a water flow setting unit that changes a water flow generated by rotation of the motor according to the estimated temperature.

According to the washing machine with the structure, the excessive temperature rise of the motor can be restrained, and high washing performance can be obtained.

Drawings

Fig. 1 is a block diagram showing an electrical configuration of a motor provided in a washing machine according to a first embodiment.

Fig. 2 is a vertical sectional side view of the washing machine according to the first embodiment.

Fig. 3 is a flowchart showing the control content of the washing operation.

Fig. 4 is a diagram showing an example of water flow that can be set during the washing operation.

Detailed Description

An embodiment of the present invention will be described below with reference to fig. 1 to 4.

The washing machine of the present embodiment is a drum-type washing machine including a drum disposed as a spin basket in an inclined state inclined forward and upward as shown in fig. 2. In the present embodiment, a drum-type washing machine is described as an example of the washing machine, but a washing machine including a vertical shaft-type spin basket may be used.

The washing machine is provided with a door 2 at the center of the front surface of an outer casing 1 constituting a housing, and an operation panel 3 at the upper part. The door 2 opens and closes a laundry loading opening 4 formed in the center of the front surface 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 with its axial direction being a front-rear direction (left-right direction in fig. 2) and in an inclined shape inclined forward and upward, and is elastically supported by an elastic support device 6. A cylindrical rotary tub (drum) 7 is disposed inside the water tub 5 coaxially with the water tub 5. The drum 7 functions as a common tub for dewatering and drying in addition to washing, and has a large number of small holes 8 formed in almost the entire area of the main body, and a plurality of baffles 9 provided on the inner periphery of the main body.

The water tub 5 and the drum 7 have

openings

10 and 11 for laundry loading, respectively, in the front surface portion, the opening 10 of the water tub 5 is connected to the laundry loading opening 4 via a bellows 12 in a watertight manner, and the opening 11 of the drum 7 faces the opening 10 of the water tub 5.

The water tank 5 is configured to be able to supply water such as tap water from the outside of the machine through a water supply port 21 provided at an upper portion of the water tank 5 via a water supply valve 20, and to discharge the water in the water tank 5 from the outside of the machine through a water discharge port 22 provided at a bottom portion of the water tank 5 via a water discharge valve 23.

A motor 14 for rotating the driving roller 7 is disposed on the back surface of the water tub 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, and the bearing housing 16 is attached to a central portion of a back portion of the water tub 5. The rotor 17 is disposed so as to cover the stator 15 from the outside, and a rotary shaft 18 attached to the center portion is rotatably supported by the bearing housing 16 via a bearing 19. A front end portion of the rotary shaft 18 protruding from the bearing housing 16 is connected to a central portion of the back of the drum 7. That is, when the rotor 17 of the motor 14 rotates, the drum 7 also rotates integrally with the rotor 17.

The operation panel 3 provided on the upper portion of the front surface of the outer box 1 includes various operation buttons including a start switch and a course selection key, and a display unit for displaying necessary contents of a set course, an operation state of the washing machine, and the like.

A control device 30 is provided on the back surface of the operation panel 3. The control device 30 includes a control unit 54, and the control unit 54 includes a microcomputer and a memory, and controls the water supply valve 20, the motor 14, and the drain valve 23 according to the operation of the operation switch of the operation panel 3 to perform washing operation of washing, rinsing, and spin-drying.

Fig. 1 is a block diagram showing the configuration of control device 30. In fig. 1, α and β represent orthogonal coordinate systems obtained by orthogonal transformation of three-phase (UVW) coordinate systems corresponding to respective phases of a three-phase brushless motor 14 and spaced at a motor angle of 120 degrees, and d and q represent coordinate systems of secondary magnetic fluxes rotating with rotation of the rotor 17 of the brushless motor 14.

The subtractor 33 shown in fig. 1 is given a target speed command ω ref as a subtrahend, and the rotational speed of the motor 14 detected by the Estimator (Estimator)34, that is, the detected speed ω, as a subtrahend. The target speed command ω ref is output from the control unit 54 that controls the overall operation of the washing machine. Then, the subtraction result of the subtractor 33 is sent to a speed PI control unit (speed control means) 35.

The speed PI control unit 35 performs PI control based on the difference between the target speed command ω ref 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 output the subtraction result between the command values Iqref and Idref generated by the speed PI control unit 35 and the q-axis current value Iq and the d-axis current value Id output from the α β/dq conversion unit 38 to the current PI control units 39q and 39 d. 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 a difference between the q-axis current reference value Iqref and the d-axis current reference value Idref, and generate and output a q-axis voltage reference value Vq and a d-axis voltage reference value Vd. The dq/α β conversion unit 40 converts the voltage command values Vd and Vq into voltage command values V α and V β based on the rotational phase angle (rotor position angle) θ of the secondary magnetic flux in the motor 14 detected by the estimator 34.

α β/UVW conversion unit 41 converts voltage command values V α, V β into three-phase voltage command values Vu, Vv, Vw and outputs them. The changeover switches 42u, 42v, and 42w switch between the voltage command values Vu, Vv, and Vw and the start voltage command values Vus, Vvs, and Vws output from the initial mode output unit 43, and output them.

The PWM forming section 44 outputs, to the power supply module 50, respective-phase PWM signals Vup (+, -), Vvp (+, -), Vwp (+, -) modulated by a 16kHz carrier wave based on the voltage command values Vus, Vvs, Vws.

The power module 50 includes an inverter circuit 45 and a drive circuit 51, and the 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 module 50 is configured by three-phase bridge-connecting 6 IGBTs 46, and the emitters of the IGBTs 46 of the lower arm side U, V phase are grounded via shunt resistors (current detection means) 47(u, v) for current detection, respectively. A common connection point of the both is connected to the a/D conversion unit 49 via an amplification/bias circuit not shown. Further, the inverter circuit 45 is applied with a dc voltage of about 280V obtained by full-wave rectifying a voltage of 100V ac power. The amplification/bias circuit amplifies the terminal voltage of the shunt resistor 47, and applies a bias voltage so that the output range of the amplified signal is on the positive side.

The a/D converter 49 outputs current data Iu and Iv obtained by a/D converting an output signal of the amplifier/bias circuit. The UVW/α β conversion unit 52 estimates current data Iw of the W phase from the current data Iu and Iv, and converts the current data Iu, Iv, Iw of the three phases into biaxial current data I α and I β of an orthogonal coordinate system.

The α β/dq conversion unit 38 obtains the rotor position angle θ of the motor 14 from the estimator 34 at the time of vector control, converts the biaxial current data I α, I β into d-axis current values Id, q-axis current values Iq, and outputs the conversion result at predetermined intervals (for example, at intervals of 128 μ seconds). The estimator 34 estimates the position angle θ and the rotation speed ω of the rotor 17 based on the d-axis current value Id and the q-axis current value Iq, and outputs the estimated position angle θ and rotation speed ω to the subtractor 33 and the control unit 54.

The controller 54 controls the operations of the water supply valve 20, the drain valve 23, the motor 14, and the like. The control unit 54 also functions as a motor temperature measuring unit that measures the temperature of the motor 14 (hereinafter also referred to as a motor temperature), an estimating unit that estimates the temperature of the motor 14 that has reached within the execution time of the washing operation (hereinafter also referred to as an arrival temperature) from the measured temperature of the motor 14, and a water flow setting unit that sets and changes the water flow during the washing operation based on the estimated arrival temperature.

In addition, in the above configuration, the configuration other than the power supply module 50 is mainly realized by software of a DSP (Digital Signal Processor).

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

When the user sets a washing course through the operation buttons provided on the operation panel 3 and instructs the start of the operation, the washing machine starts the washing operation according to the set washing course.

When the washing operation is started, controller 54 drives motor 14 in step S1, rotates drum 7, detects the weight of the laundry stored therein, and proceeds to step S2.

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

In step S3, controller 54 sets drain valve 23 to the closed state, opens water supply valve 20, and supplies washing water into water tub 5 until the water level reaches the water level set in step S2.

When the supply of the washing water into the water tub 5 is completed, the flow proceeds to step S4, and the controller 54 drives the motor 14 to rotate the drum 7 alternately in the forward and reverse directions at a low speed, agitates the washing water and the laundry in the drum 7, and executes the washing operation (washing stroke) until the washing time set in step S2 elapses.

After the washing operation is started, the control unit 54 performs initial temperature measurement in which the motor temperature is measured a plurality of times at predetermined intervals (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, measures the motor temperature 2 times every 30 seconds, and measures the motor temperature 3 times in the initial temperature measurement.

As a method for measuring the motor temperature by the control unit 54, for example, the coil temperature of the stator 15 of the motor 14 may be measured based on the d-axis current value Id output from the α β/dq conversion unit 38, the temperature of the motor 14 may be measured by providing a temperature sensor at a predetermined position of the motor 14 such as the coil of the stator 15, or the temperature of the power module 50 provided in the control device 30 may be measured by the temperature sensor, and the measured temperature may be used as the motor temperature.

When the initial temperature measurement is completed, the process proceeds to step S6, and the control unit 54 estimates the 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 X represents the elapsed time from the start of the washing operation and T represents the measured motor temperature, assuming that the motor temperature T with respect to the elapsed time X is expressed by an estimation function of the following equation (1), the coefficients (a, b) of the following equation (1) are obtained by using a multidimensional least squares method from the data set of the elapsed time X and the motor temperature T obtained in the initial temperature measurement in step S5, and the estimation function of the estimated motor temperature T is obtained.

T ═ a · ln (x) + b equation (1)

Then, the control unit 54 substitutes the washing time set in step S2 into the obtained estimation function of the estimated motor temperature T, and calculates the reaching temperature Te reached by the motor 14 during execution of the washing operation based on the estimation function (step S6).

In step S7, control unit 54 changes the setting of the water flow in the washing operation based on the arrival temperature Te calculated in step S6. Specifically, in the present embodiment, the control unit 54 sets the water flow conditions as follows: the intensity of the water flow in the washing operation is made to decrease with the increase in the reaching temperature Te calculated in step S6.

For example, a plurality of water flow conditions as shown in fig. 4 are stored in the control unit 54 in association with the arrival temperature Te, the water flow condition corresponding to the arrival temperature Te calculated in step S6 is selected, and the rotation of the motor 14 is controlled in accordance with the selected condition, so that the water flow condition is set such that the intensity gradually decreases as the arrival temperature Te increases.

In the case of fig. 4, when the arrival temperature Te calculated in step S6 is less than 80 ℃, the control unit 54 sets the ON time for rotating the drum 7 to 5 seconds, and sets the OFF time for temporarily stopping the drum 7 when the rotation direction of the drum 7 is reversed to 0 second. When the reached temperature Te is 80 ℃ or higher and less than 100 ℃, the control unit 54 sets the ON time and the OFF time to 5 seconds and 1 second; setting ON time and OFF time to 5 seconds and 3 seconds when the reaching temperature Te is not less than 100 ℃ and less than 120 ℃; when the reached temperature Te is 120 ℃ or higher, the ON time and the OFF time are set to 5 seconds and 5 seconds. Further, the maximum rotation speed of the drum 7 is set to 50rpm at any reaching temperature Te.

In addition to the manner of changing the OFF time as described above, the change of the water flow condition may be changed, for example, as follows: that is, the intensity of the water current is weakened by decreasing the maximum rotation speed, or the intensity of the water current is weakened by shortening the ON time, or the intensity of the water current is weakened by combining the above.

In step S8, the control unit 54 determines whether the washing time set in step S2 has elapsed, ends the washing operation if the washing time has elapsed, and proceeds to step S9 if the washing time has not elapsed.

In step S9, the control unit 54 determines whether or not a predetermined time (hereinafter also referred to as a measurement time) has elapsed since the motor temperature was measured last time, and if the measurement time has elapsed, the routine proceeds to step S10 to measure the motor temperature. The measurement time can be set to 30 seconds, for example.

After the measurement of the motor temperature is completed in step S10, the control unit 54 proceeds to step S11, obtains the coefficients (a, b) of the above equation (1) by using a multidimensional least square method from a data set obtained by adding the data obtained in step S11 to a data set of the elapsed time X and the motor temperature T obtained after the start of the washing operation, and updates the estimation function of the estimated motor temperature T. Then, the control part 54 calculates again the reaching temperature Te reached by the motor 14 within the washing time set in step S2 based on the updated function, and updates the reaching temperature Te (step S11).

Then, after updating the reaching temperature Te, the control unit 54 returns to step S7 to change the setting of the water flow during the washing operation based on the updated reaching temperature Te.

Then, until the washing time set in step S2 elapses, the control unit 54 repeats the following operations: that is, the motor temperature is measured every time the measurement time elapses (step S9) (step S10), the data obtained every time the measurement is added to the data set of the elapsed time X and the motor temperature T obtained after the washing operation is started, the estimated function of the estimated motor temperature T and the reached temperature Te are updated based on the data set obtained by the addition (step S11), and the setting of the water flow is changed according to the updated reached temperature Te (step S7).

When the washing time set in step S2 has elapsed (yes in step S8), control unit 54 ends the washing operation and proceeds to the spin-drying operation.

In the washing machine of the present embodiment, since the rotation of the motor 14 is controlled to estimate the reached temperature Te from the motor temperature measured a plurality of times at intervals and the water flow is changed according to the estimated reached temperature Te, it is possible to perform appropriate rotation control according to a change in the motor temperature, and it is possible to prevent the motor 14 from being damaged while suppressing an excessive increase in the temperature of the motor 14, without unnecessarily lowering the washing performance due to an excessive suppression of the operation of the motor 14.

In the present embodiment, since the control unit 54 measures the motor temperature every time the measurement time elapses after the rotation control of the motor 14 is changed based on the arrival temperature Te estimated based on the initial temperature, and calculates the arrival temperature Te again in conjunction with the motor temperature measured so far and updates the arrival temperature Te, it is possible to further perform appropriate rotation control in accordance with the change in the motor temperature.

(modification 1)

In the above embodiment, 1 type of function is used as the estimation function for estimating the motor temperature, but the reached temperature Te may be estimated using a plurality of types of functions.

For example, it is possible to select 1 function from a plurality of estimation functions from the motor temperature measured immediately after the start of the washing operation in the initial temperature measurement, and calculate the reached temperature Te using the selected estimation function. The reaching temperature Te may be calculated by changing the function of the estimated motor temperature according to the washing course set by the user using the operation buttons of the operation panel 3.

In this case, the function is changed based on the motor temperature measured immediately after the washing operation is started, so that the motor temperature can be estimated with high accuracy, and appropriate rotation control can be performed in accordance with the change in the motor temperature.

Even if there is a course in which laundry is likely to be entangled, the load is increased, and the motor temperature is likely to increase due to the progress of the washing operation, or there is a course in which the load applied to the motor 14 is small and the motor temperature is unlikely to increase, the motor temperature can be estimated with high accuracy by changing the estimation function according to the washing progress, and appropriate rotation control according to the change in the motor temperature can be performed.

(modification 2)

In the above embodiment, the control unit 54 calculates the reached temperature Te regardless of the motor temperature measured by the motor temperature measuring unit, but, for example, when the motor temperature measured by the motor temperature measuring unit is equal to or higher than a predetermined temperature, the control unit 54 may stop the motor 14 to stop the washing operation without calculating or updating the reached temperature Te. In this case, the rotation of the motor 14 can be stopped urgently to prevent the motor 14 from being damaged.

(other embodiments)

Although the embodiments of the present invention have been described above, these embodiments are provided as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, substitutions, and changes can be made without departing from the spirit of the invention. These embodiments and modifications are included in the scope and spirit of the invention, and are included in the scope of the invention described in the claims and the equivalent scope thereof.

Claims

1. A washing machine is provided with:

a motor;

a motor temperature measuring unit for measuring the temperature of the motor; and

a control part for performing washing operation by driving and controlling the motor to stir the washing water and the washings together; it is characterized in that the preparation method is characterized in that,

the control unit includes: an estimating part for estimating the reaching temperature of the motor in the executing process of the washing operation according to the temperature of the motor measured by the motor temperature measuring part for a plurality of times at intervals; and a water flow setting unit that changes a water flow generated by rotation of the motor in accordance with the arrival temperature estimated by the estimation unit,

the estimating unit updates the arrival temperature based on the temperature of the motor measured by the motor temperature measuring unit after the water flow generated by the rotation of the motor is changed by the water flow setting unit based on the arrival temperature estimated by the estimating unit and the temperature of the motor obtained by the motor temperature measuring unit from the start of the washing operation,

the water flow setting unit changes the water flow based on the arrival temperature updated by the estimation unit,

the arrival temperature is estimated by an estimation function of the following formula (1),

T＝a·ln(X)+b (1)

in the above formula (1), X is an elapsed time from the start of the washing operation, T is a motor temperature, and a and b are coefficients determined based on the elapsed time from the start of the washing operation and the measured motor temperature.

2. The washing machine as claimed in claim 1,

the water flow setting portion reduces the intensity of the water flow by reducing the maximum rotation speed of the motor.

3. The washing machine as claimed in claim 1,

the motor temperature measuring unit measures the temperature of the motor based on the coil temperature of the motor.

4. A washing machine according to claim 3,

the motor temperature measuring unit measures the temperature of the motor based on the value of current flowing through the motor.

5. The washing machine as claimed in claim 1,

the motor temperature measuring part measures the temperature of the motor according to the temperature of the power module of the motor.

6. A washing machine according to any one of claims 1 to 5,

after the washing operation is started, the estimating part changes an estimating function for estimating the reaching temperature according to the temperature of the motor initially measured by the motor temperature measuring part.

7. A washing machine according to any one of claims 1 to 5,

the estimating part changes an estimating function for estimating the arrival temperature according to the washing course executed.

8. A washing machine according to any one of claims 1 to 4,

when the temperature of the motor measured by the motor temperature measuring part is more than or equal to the specified temperature, the control part stops the washing operation.