TWI856180B - Washing Machine - Google Patents

Abstract

The washing machine disclosed in the present invention is equipped with: a stirring blade rotatably arranged in a washing and dewatering tank; a motor having a permanent magnet and a winding; a power supply circuit for supplying current to the motor; and a current detection unit for detecting the current of the motor. In addition, it is equipped with: a transmission mechanism for transmitting the torque of the motor to the stirring blade; a rotation number control unit for controlling the motor to a predetermined rotation number; and a control unit for performing a predetermined number of acceleration control, constant speed control, or stop control on the motor in sequence and alternately from left to right. In addition, the control unit is provided with a cloth amount detection unit, which detects the amount of laundry from the average current value during the constant speed control period or the rotation angle during the stop control period.

Description

Washing Machine

This disclosure relates to a washing machine.

In the past, such a washing machine performed cloth amount determination as described below, as shown in Japanese Patent Publication No. 2014-54498. Cloth amount determination refers to measuring the amount of cloth put into the washing machine, and a washing method has been proposed that corresponds the water level or the number of rotations to the amount of cloth. In order to improve the accuracy of cloth amount determination, the cloth amount determination is performed based on the current value when the acceleration of the washing tub during acceleration and deceleration is set to a certain ratio.

In the past, this type of washing machine performed water flow correction control as described below, as shown in Japanese Patent Publication No. 2006-68275. A method was proposed in which the current during a certain period at the beginning of agitation is used to predict the scattering of washing water from the washing tank. When the current is large, it is predicted that the washing water will scatter, and the water flow is changed to a weaker one in advance to prevent the scattering.

However, such conventional washing machines have the following problems: Since the washing tub is rotated, it is more susceptible to imbalance when the cloth is biased, and it takes time to eliminate the imbalance. Another problem is that since the position sensor is used for rotation number detection, it becomes expensive and is limited by the structure.

The present disclosure provides a washing machine that can easily detect the amount of cloth with better accuracy even without a position sensor.

The washing machine disclosed in the present invention is equipped with: a stirring blade, which is rotatably arranged in a washing and dehydrating tank; a motor, which has a permanent magnet and a winding; a power supply circuit, which supplies current to the motor; and a current detection unit, which detects the current of the motor. In addition, it is equipped with: a transmission mechanism, which transmits the torque of the motor to the stirring blade; a rotation number control unit, which controls the motor to a predetermined rotation number; and a control unit, which performs a predetermined number of acceleration control, constant speed control, or stop control on the motor in sequence and alternately from left to right. In addition, the control unit is provided with a cloth amount detection unit, which detects the amount of laundry from the average current value during the constant speed control period or the rotation angle during the stop control period.

Even without a position sensor, the washing machine disclosed in the present invention can still easily detect the amount of cloth with good accuracy.

In addition, conventional washing machines have the following problems: When the laundry is large, the current will increase, which will weaken the water flow. Therefore, if the laundry is large, it will take longer to wash, and the washing performance cannot be satisfied. In addition, there is the following problem: since the position sensor is used to correct the water flow to prevent the splashing of washing water, it will become expensive and will be limited by the structure.

The present disclosure provides a washing machine that can be controlled with normal water flow without splashing even without a position sensor, thereby ensuring the washing performance.

The washing machine disclosed in the present invention is equipped with: a stirring blade, which is rotatably arranged in a washing and dehydrating tank; a motor, which has a permanent magnet and a winding; a power supply circuit, which supplies current to the motor; and a current detection unit, which detects the current of the motor. In addition, it is equipped with: a transmission mechanism, which transmits the torque of the motor to the stirring blade; a rotation number control unit, which controls the motor to a predetermined rotation number; and a control unit, which performs a predetermined number of acceleration control, constant speed control, or stop control on the motor in sequence and alternately from left to right. In addition, the control unit corrects the washing water flow according to the rotation angle during the stop control period.

The washing machine disclosed in the present invention can predict the splashing of washing water without depending on the amount of laundry. Moreover, even without a position sensor, it can still be controlled with normal water flow to ensure the washing performance at a level without splashing. In the case of splashing, the water flow is weakened to prevent splashing before it occurs.

1: Pulsator (stirring blade)

2: Washing and dewatering sink

3: Water storage tank

4: Motor (electric motor)

4a,4b,4c: Winding

4d: Permanent magnet (rotor)

5: Belt (transmission mechanism)

6: Speed reduction mechanism and clutch (transmission mechanism)

7: Gear motor

8: Brake belt

9: Washing machine frame

10: Panel section

11: Cover

12: Display unit

13: Control device

14: Water supply valve

15: Drain valve

16: Rectifier circuit

17: Commutation circuit (power circuit)

18: Current detection unit (current detection unit)

19: PWM control unit

20: Control Department

21: Speed phase estimation unit

22: Three-phase to two-phase converter

23:Iδ error amplifier

24:Iγ error amplifier

25: Two-phase and three-phase converter

26: Speed error amplifier

27: Weak magnetic field setting unit

28:γ-axis induced voltage calculator

29:γ-axis induced voltage error amplifier

31: Pulley (transmission mechanism)

32: Impeller pulley (transmission mechanism)

d,q,γ,δ:axis

Iu, Iv, Iw: phase current

Iγ:γ axis current

Iγs:γ-axis current command

Iδ:δ axis current

Iδs:δ-axis current command

Kθ: proportional gain

Kω: integral gain

L: Inductance value

Ra: resistance value

U,V,W: phase

Va: Input voltage

Vdc: Direct current voltage

Ve: Induced voltage vector

Veγ:γ-axis induced voltage

Veγs:γ-axis induced voltage command

Vu, Vv, Vw: output voltage

Vus, Vvs, Vws: three-phase voltage, three-phase motor drive control voltage command, applied voltage

Vγs: Command γ-axis voltage

Vδs: Command δ axis voltage

θ: phase, electrical angle, estimated phase, motor rotation angle, rotation angle

θc: phase

ω: speed, electrical angle speed, estimated speed, motor rotation speed

ωs: speed command, motor command rotation speed, motor specified rotation speed

△Iγ: Error relative to the command value of the γ-axis current

△Iδ: Error relative to the command value of the δ-axis current

△Veγ:γ-axis induced voltage error

△θ: Error, estimated phase error

△ω: Error relative to speed command

α : Motor acceleration

S100~S112,S200~S205,S300~S311,S307a,S400~S411,S500~S503,S600~S608,S700~S706,S800~S814,S1100~S1112,S1200~S1205,S1300~S1305,S1400~S1411,S1500~S1508,S1600~S1606,S1700~S1712: Steps

Figure 1 is a cross-sectional view of the main parts of the washing machine in the first embodiment.

FIG. 2 is a block diagram of the motor drive system of the washing machine in the first embodiment.

FIG3 is an equivalent circuit diagram of the motor of the washing machine in the first embodiment.

FIG4 is a control block diagram for estimating the motor phase of the washing machine in the first embodiment.

FIG5 is a detailed block diagram of the motor speed phase estimation unit of the washing machine in the first embodiment.

FIG. 6A is a vector diagram showing the estimated coordinates in a delayed state when estimating the phase of the motor of the washing machine in the first embodiment.

FIG. 6B is a vector diagram showing the estimated coordinates in the leading state when estimating the phase of the motor of the washing machine in the first embodiment.

FIG7 is a flow chart of cloth amount detection control of the washing machine in the first embodiment.

FIG8 is a flow chart of the cloth amount detection acceleration control of the washing machine in the first embodiment.

FIG9 is a flow chart of cloth amount detection constant speed control of the washing machine in the first embodiment.

FIG10 is a flow chart of the cloth amount detection deceleration control of the washing machine in the first embodiment.

FIG11 is a flow chart of the cloth amount detection and determination output of the washing machine in the first embodiment.

FIG. 12A is a relationship diagram between the average Iq of the cloth amount detection output and the cloth amount determination value of the washing machine in the first embodiment.

FIG. 12B is a relationship diagram between the cumulative calculation rotation angle and the cloth amount determination value of the cloth amount detection and determination output of the washing machine in the first embodiment.

FIG. 13 is a timing diagram of the detection Iq and the rotation angle under the cloth amount detection of the washing machine in the first embodiment.

FIG. 14 is a flow chart of the motor speed control process of the washing machine in the first embodiment.

FIG. 15 is a flowchart of the motor stop control process of the washing machine in the first embodiment.

FIG. 16 is a flow chart of the motor current control process of the washing machine in the first embodiment.

FIG. 17 is a flow chart of cloth amount detection constant speed control of the washing machine in the second embodiment.

FIG. 18 is a timing diagram of the detection Iq under cloth amount detection of the washing machine in the second embodiment.

FIG. 19 is a flow chart of the water flow correction control of the washing machine in the third embodiment.

FIG. 20 is a flow chart of the acceleration control of the water flow correction of the washing machine in the third embodiment.

FIG. 21 is a flow chart of the constant speed control of the water flow correction of the washing machine in the third embodiment.

FIG. 22 is a flow chart of the deceleration control of the water flow correction of the washing machine in the third embodiment.

FIG. 23 is a relationship diagram between the cumulative calculation rotation angle of the judgment output of the water flow correction control of the washing machine in the third embodiment and the judgment water flow under the water flow correction control.

FIG. 24 is a timing diagram for detecting the rotation angle of the water flow correction control of the washing machine in the third embodiment.

FIG. 25 is a flow chart of the motor speed control process of the washing machine in the third embodiment.

FIG. 26 is a flowchart of the motor stop control process of the washing machine in the third embodiment.

FIG. 27 is a flow chart of the motor current control process of the washing machine in the third embodiment.

The form used to implement the invention

The following is an explanation of the implementation form of the present disclosure with reference to the drawings. In addition, the present disclosure is not limited to this implementation form.

(First implementation form)

Figure 1 is a cross-sectional view of the main parts of the washing machine in the first embodiment.

The pulsator 1 for stirring clothes is arranged at the bottom so that it can rotate freely left and right, and the washing and dehydrating tank 2 is configured to rotate freely inside the water storage tank 3 for dehydration. The motor 4 is fixed to the outer bottom of the water storage tank 3, and the rotation of the motor 4 is driven or braked by the motor pulley 31, the belt 5, the impeller pulley 32, and the speed reduction mechanism and clutch 6 to rotate the pulsator 1 or the washing and dehydrating tank 2.

There is a speed reduction ratio (e.g., 1/4) between the motor pulley 31 and the impeller pulley 32, and the following relationship exists: when the motor pulley 31 mounted on the motor shaft (not shown) of the motor 4 rotates 4 times, the impeller pulley 32 (or the washing and dewatering tank 2) mounted on the impeller shaft (not shown) of the speed reduction mechanism and clutch 6 will rotate 1 time.

Similarly, the speed reduction mechanism and clutch 6 located between the impeller pulley 32 and the pulsator 1 has a speed reduction ratio (for example, 1/6), and has the following relationship: when the impeller pulley 32 mounted on the impeller shaft rotates 6 times, the pulsator 1 mounted on the pulsator shaft (not shown) rotates 1 time.

In addition to the method of controlling the brake to apply reverse torque to the motor 4, there is also the following method: the geared motor 7 is activated to make the brake belt 8 contact the rotating part, thereby mechanically braking the washing and dewatering tank 2. On the top surface of the panel part 10 arranged above the outer frame 9 of the washing machine, a cover 11 is set in a freely openable and closable manner, and on the front inner side of the panel, a control device 13 that controls the entire washing machine stroke and has a display part 12 is arranged.

The control device 13 has a control unit 20 formed by a microcomputer. The aforementioned microcomputer controls the actions of the motor 4, the water supply valve 14, the drain valve 15, etc. to sequentially control a series of processes such as washing, cleaning, and dehydration. The control unit 20 is based on the information from the input setting unit for the user to operate the desired washing process setting or operation start, temporary stop, etc., and displays the process progress display or various information to notify the user through the display unit 12 formed by the light-emitting element such as LED or LCD. When the operation is set to start through the input setting unit, the gear motor 7, the water supply valve 14, and the drain valve 15 will be controlled in response to the data from the water level detection unit to perform the washing operation.

FIG2 is a block diagram of the motor drive system of the washing machine in the first embodiment.

The AC power source applies AC power to the rectifier circuit 16, which is composed of a voltage doubler rectifier circuit, and applies the voltage doubler DC voltage to the commutation circuit 17. The commutation circuit 17 is composed of a three-phase full-bridge commutation circuit and an intelligent power module (hereinafter referred to as IPM). The three-phase full-bridge commutation circuit is formed by 6 power switching semiconductors and anti-parallel diodes. The intelligent power module is usually built-in with an insulated gate bipolar transistor (IGBT) and an anti-parallel diode and its driving circuit and protection circuit. The motor 4 is connected to the output terminal of the commutation circuit 17 for driving.

The current detection unit (current detection unit) 18 connects a shunt resistor between the negative voltage terminal of the commutation circuit 17 and the negative voltage terminal of the rectifier circuit 16, and detects the phase currents Iu, Iv, and Iw of the motor 4 based on the input current of the commutation circuit 17 calculated from the voltage at both ends of the shunt resistor. Since the DC voltage applied to the commutation circuit 17 is not only input from the AC power source, but also overlapped by the regenerative energy generated by the rotation of the motor, it is always detected.

The PWM control unit 19 controls the PWM signal switched by the IGBT of the commutation circuit 17 in response to the three-phase motor drive control voltage instructions Vus, Vvs, and Vws from the control unit 20, and drives the motor 4 by the output voltages Vu, Vv, and Vw of the commutation circuit.

FIG3 is an equivalent circuit diagram of the motor of the washing machine in the first embodiment.

In order to simplify the explanation, a two-pole structure is used in which one rotation of the mechanical angle becomes one rotation of the electrical angle. When the number of poles is changed to four poles, eight poles, etc., one rotation of the mechanical angle becomes two rotations, four rotations, etc. of the electrical angle. The motor 4 is a three-phase synchronous motor, and is composed of an equivalent circuit of windings 4a, 4b, 4c having three phases of U, V, and W, and a rotor, i.e., a permanent magnet 4d, that rotates around the center of the rotation axis. In this equivalent circuit, the axis that passes through the permanent magnet with the N-pole side as the positive direction is defined as the d-axis (direct-axis), and the axis orthogonal thereto is defined as the q-axis (quadrature-axis). If defined in this way, the magnetic field in the q-axis direction will be the main factor controlling the motor torque. In addition, the phase (electrical angle) is the rotation angle θ between the axis passing through the U-phase winding and the d-axis. All the phases described below are electrical angles. In addition, the inductance of the winding when a voltage is applied to generate a magnetic field in the d-axis direction is set to Ld, and the inductance in the q-axis direction is similarly set to Lq.

The relationship of embedded magnet type three-phase synchronous motor is Ld<Lq. In addition, since the control unit 20 described later cannot correctly detect the position of the rotor at the beginning, as shown in Figure 3, it assumes a phase θc, and an error △θ occurs with the actual phase θ. That is, the axis controlled by the microcomputer assuming a phase θc becomes the γ axis (estimated d axis) and the δ axis (estimated q axis) relative to the actual motor d axis and q axis. After that, the current component corresponding to the torque in the microcomputer is set as the δ-axis current Iδ, the current component corresponding to the magnetic flux in the microcomputer is set as the γ-axis current Iγ, the voltage component corresponding to the torque in the microcomputer is set as the command δ-axis voltage Vδs, and the voltage component corresponding to the magnetic flux in the microcomputer is set as the command γ-axis voltage Vγs.

FIG4 is a control block diagram for estimating the motor phase of the washing machine in the first embodiment.

The control unit 20 is composed of a microcomputer (microcomputer), a commutation control timer (timer) built into the microcomputer, A/D conversion, a memory circuit, a speed phase estimation unit 21, a three-phase two-phase converter 22, an Iδ error amplifier 23, an Iγ error amplifier 24, a two-phase three-phase converter 25, a speed error amplifier 26, a weak magnetic field setting unit 27, etc., and performs commutation control as described below.

The details of the speed phase estimation unit 21 are described later. The speed phase estimation unit 21 inputs the δ-axis current Iδ, the γ-axis current Iγ, and the command γ-axis voltage Vγs, and outputs the speed (electrical angle speed) ω and the estimated phase θ. All the speeds described below are electrical angle speeds.

The three-phase to two-phase converter 22 calculates the γ-axis current Iγ and the δ-axis current Iδ using equation 1 from the electrical angle θ and the phase currents Iu, Iv, Iw, as well as the sine wave data (sin, cos data) required to convert from a stationary coordinate system to a rotating coordinate system.

The Iδ error amplifier 23 inputs the error △Iδ relative to the command value Iδs of the δ-axis current from the δ-axis current command Iδs obtained by the speed error amplifier 26 and the δ-axis current Iδ obtained by the three-phase two-phase converter 22, and outputs the command δ-axis voltage Vδs as the sum of the proportional component and the integral component.

Similarly, the Iγ error amplifier 24 inputs the error △Iγ relative to the command value Iγ of the γ-axis current from the γ-axis current command Iγs obtained by the weak magnetic field setting unit 27 and the γ-axis current Iγ obtained by the three-phase two-phase converter 22, and outputs the command γ-axis voltage Vγs as the sum of the proportional component and the integral component.

The axis is then decomposed into the δ-axis current Iδ and the γ-axis current Iγ, which are controlled independently, so it is called vector control.

The two-phase to three-phase converter 25 calculates the sinusoidal instructions, i.e., the three-phase voltages Vus, Vvs, and Vws, from the phase θ, the command δ-axis voltage Vδs, the command γ-axis voltage Vγs, and the sine wave data (sin, cos data) required for the reverse conversion from the rotational coordinate system to the static coordinate system using Formula 2.

The speed error amplifier 26 inputs the error Δω relative to the speed command ωs from the speed command ωs and the speed ω calculated by the speed phase estimation unit 21, and outputs the δ-axis current command Iδs which is the sum of the proportional component and the integral component.

The weak magnetic field setting unit 27 calculates the negative direction γ-axis current command Iγs from the speed ω calculated by the speed phase estimation unit 21 and the DC voltage Vdc input to the commutation circuit, and performs weak magnetic flux control.

FIG5 is a detailed block diagram of the motor speed phase estimation unit of the washing machine in the first embodiment.

The estimated phase θ is calculated using the resistance value Ra and inductance value L of the windings 4a, 4b, and 4c, which are parameters of the motor 4.

The speed phase estimation unit 21 is formed by a γ-axis induced voltage calculator 28 and a γ-axis induced voltage error amplifier 29.

The γ-axis induced voltage calculator 28 calculates the γ-axis induced voltage Veγ using equation 3 from the inductance value L, the resistance value Ra, the δ-axis current Iδ, the γ-axis current Iγ, the commanded γ-axis voltage Vγs, and the estimated speed ω.

[Formula 3] V _eγ = V _γs -(R _a ×l _γ -ω×L×l _δ )

Assume that the γ-axis induced voltage command Veγs=0, and input the error △Veγ relative to the γ-axis induced voltage command Veγs into the γ-axis induced voltage error amplifier 29.

The γ-axis inductive voltage error amplifier 29 outputs the estimated speed ω calculated from the integral gain Kω, adds the estimated speed ω to the value calculated from the proportional gain Kθ, and performs time integration through an integrator to output the estimated phase θ.

However, the γ-axis induced voltage calculator 28 is not limited to using Formula 3, and can also be calculated by using Formula 4 with a time differential term.

[Formula 4] V _eγ = V _γs -(R _a ×l _γ +L×(dl _γ /dt)-ω×L×l _δ )

In addition, regarding the inductance L in the above formulas, although the same L value can be used as long as the motor 4 has the characteristic of Ld=Lq, even if the motor 4 has the characteristic of Ld≠Lq, it can be calculated to a certain L value (=Lq).

FIG. 6A is a vector diagram showing that the estimated coordinates of the motor phase of the washing machine in the first embodiment are in a delayed state (the γδ coordinates (estimated dq coordinates) are slightly delayed relative to the dq coordinates of the motor 4), and FIG. 6B is a vector diagram showing that the estimated coordinates of the motor phase of the washing machine in the first embodiment are in an advanced state (the γδ coordinates (estimated dq coordinates) are slightly advanced relative to the dq coordinates of the motor 4).

In the vector diagram, the γ-axis induced voltage error △Veγ is the γ-axis component of the estimated induced voltage vector Ve (=ω×Ψa) after subtracting the drop of the current flowing through Ra and ωL from the input voltage Va of motor 4. Since the induced voltage vector Ve is always on the q-axis, when the estimated phase error △θ (the state of the γδ coordinates in the counterclockwise direction relative to the dq coordinates is set to positive) is 0, the q-axis is consistent with δ. In Figure 6A, the estimated phase error △θ becomes negative (△θ<0), and in Figure 6B, the estimated phase error △θ becomes positive (△θ>0).

By using the γ-axis induced voltage error amplifier 29, the estimated speed ω is increased in the case of FIG. 6A to make θ more advanced, and the estimated speed ω is reduced in the case of FIG. 6B to make θ delayed, thereby performing feedback control to make the γ-axis induced voltage error △Veγ and the estimated phase error △θ become 0. In this way, since the phase estimation is based on the motor rotation state with the induced voltage Ve, the phase estimation will be unstable in the low speed zone when the induced voltage is low or when the vehicle stops, and the open loop control without phase estimation is used in the low speed zone.

In the above configuration, using Figures 7 to 16 and Tables 1 to 3, the cloth amount detection control of the washing machine in the first embodiment is described.

FIG7 is a flow chart of cloth amount detection control of the washing machine in the first embodiment.

The cloth amount detection control starts from step S100. In step S101, the number of reversals n is cleared to 0. In step S102, the motor command rotation number ωs is cleared to 0. In step S103, the cloth amount detection acceleration control processing routine is entered (details are recorded later). In step S104, the cloth amount detection constant speed control processing routine is entered (details are recorded later). In step S105, the cloth amount detection deceleration control processing routine is entered (details are recorded later).

In step S106, the number of reversal n is added +1. In step S107, it is confirmed whether the number of reversal n is greater than the set judgment number ns (for example, 4 times). If it is greater (yes), it proceeds to step S108, and if it is the same or smaller (no), it proceeds to step S109. In step S108, it enters the cloth amount detection judgment output processing routine (the details are described later). In step S109, if the rotation direction is CW (clockwise), it is changed to CCW (counterclockwise), and if it is CCW, it is changed to CW. Step S110 is entered from "A" of other processing routines. In step S111, the maximum (for example, 10kg) is input as the cloth amount judgment value. In step S112, the cloth quantity detection control is terminated.

FIG8 is a flow chart of the cloth amount detection acceleration control of the washing machine in the first embodiment.

The cloth amount detection acceleration control starts from step S200. In step S201, the motor acceleration α (for example, 3000 (r/min)/s) is called. In step S202, the motor specified rotation number ωs is added according to the motor acceleration α. In step S203, the motor speed control processing routine is entered (the details are described later). In step S204, it is confirmed whether the motor specified rotation number ωs is greater than the motor command maximum rotation number ωmax (for example, 2160r/min). If it is greater (yes), it enters step S205. If it is less than (no), it enters step S201. In step S205, the cloth amount detection acceleration control ends.

FIG9 is a flow chart of cloth amount detection constant speed control of the washing machine in the first embodiment.

The cloth quantity detection constant speed control starts from step S300. In step S301, the ON time limit timer T_ontm is cleared to 0.

In step S302, check whether the number of reversal times n is 0. If it is 0 (yes), proceed to step S303. If it is not 0 (no), proceed to step S305. In step S303, clear the cumulative operation IqIq_integral to 0. In step S304, clear the cumulative operation times integral_n to 0. In step S305, enter the motor speed control processing routine (details are described later). In step S306, add the motor speed control processing time (for example, 1ms) to the ON time limit timer T_ontm.

In step S307, it is confirmed whether the ON time limit timer T_ontm is smaller than the cumulative operation delay time T_delay (for example, 0.3s). If it is smaller (yes), it proceeds to step S310. If it is equal to or larger (no), it proceeds to step S308. In step S308, Iq is added to the cumulative operation IqIq_integral. In step S309, 1 is added to the cumulative operation number integral_n. In step S310, it is confirmed whether the ON time limit timer T_ontm is larger than the ON time limit T_on. If it is larger (yes), it proceeds to step S311. If it is equal to or smaller (no), it proceeds to step S305. In step S311, the cloth quantity detection constant speed control is terminated.

FIG10 is a flow chart of the cloth amount detection deceleration control of the washing machine in the first embodiment.

The cloth quantity detection deceleration control starts from step S400. In step S401, it is confirmed whether the number of reversal times n is 0. If it is 0 (yes), it proceeds to step S402. If it is not 0 (no), it proceeds to step S404.

In step S402, the OFF time limit timer T_offtm is cleared to 0. In step S403, the accumulated rotation angle θ_integral is cleared to 0. In step S404, the routine for motor speed stop control is entered (details are described later). In step S405, it is confirmed whether the motor rotation angle θ is smaller than the angle threshold θ_limit (later, the angle is set to the motor electrical angle). If it is smaller (yes), it enters step S406. If it is equal to or larger (no), it enters step S407. In step S406, the motor stop control processing time (for example, 1ms) is added to the OFF time limit timer T_offtm. In step S407, it enters "A" (refer to Figure 7).

In step S408, check whether the motor rotation number ω is smaller than the minimum detection rotation number ω_min (for example, 100r/min). If it is smaller (yes), proceed to step S410. If it is equal to or larger (no), proceed to step S409. In step S409, add the motor rotation angle θ to the cumulative calculation rotation angle θ_integral. In step S410, check whether the OFF time limit timer T_offtm is larger than the OFF time limit T_off. If it is larger (yes), proceed to step S411. If it is equal to or smaller (no), proceed to step S404. In step S411, end the cloth amount detection deceleration control.

FIG11 is a flow chart of the cloth amount detection and determination output of the washing machine in the first embodiment.

The cloth quantity detection and determination output starts from step S500. In step S501, the average Iq is calculated using formula 5.

In step S502, the judgment value is output. The judgment method is described in detail in Figure 12A, Figure 12B, Table 1 to Table 3. In step S503, the cloth quantity detection judgment output is completed.

FIG. 12A is a relationship diagram between the average Iq of the cloth amount detection and judgment output of the washing machine in the first embodiment and the cloth amount judgment value, and FIG. 12B is a relationship diagram between the cumulative operation rotation angle of the cloth amount detection and judgment output of the washing machine in the first embodiment and the cloth amount judgment value. The points in FIG. 12A and FIG. 12B are evaluation values (average Iq and cumulative operation rotation angle, respectively) at each cloth amount (for example, 2kg, 4kg, 6kg, 8kg, 10kg), and the dotted line is an approximate line connecting these points. As shown by the arrow line, the threshold for judging each cloth amount judgment value (for example, 0~3kg, 3~5kg, 5~7kg, 7~9kg, 9kg~) is determined from the evaluation value. This is performed multiple times at each cloth amount, and the threshold is set to take into account the deviation of the evaluation value.

Table 1 shows the cloth amount determination value determined from the average Iq of the cloth amount detection and determination output of the washing machine in the first embodiment, Table 2 shows the cloth amount determination value determined from the cumulative calculation rotation angle of the cloth amount detection and determination output of the washing machine in the first embodiment, and Table 3 shows the cloth amount determination value determined from the average Iq of the cloth amount detection and determination output of the washing machine in the first embodiment and the cumulative calculation angle.

As shown in Figure 12A, since the average Iq and the cloth amount determination value are nearly proportional, the average Iq can be used to subtract the threshold value for larger cloth amounts. Based on this, the cloth amount determination value such as that in Table 1 can be set from the average Iq.

On the other hand, as shown in FIG12B, since the cumulative calculation rotation angle and the cloth amount judgment value are close to an inversely proportional relationship, although the cumulative calculation rotation angle changes less under a larger amount of cloth and makes the threshold value denser, the cumulative calculation rotation angle changes more under a smaller amount of cloth and is easier to reduce the threshold value. Therefore, there is a tendency to be good at judgment under a lower amount of cloth. Based on this, the cloth amount judgment value such as Table 2 can be set from the cumulative calculation rotation angle.

In addition, Table 3 makes use of these characteristics. The larger amount of cloth is determined by the average Iq, while the smaller amount of cloth is determined by the cumulative calculation rotation angle. That is, if the average Iq is less than 0.5A, the cloth amount determination value is determined to be 0~3kg or 3~5kg according to whether the cumulative calculation rotation angle is greater than 112rev or less than 112rev. If the average Iq is greater than 0.5A, the cloth amount determination value is determined to be 5~7kg, 7~9kg, or 9kg~ according to whether it is less than 0.9A, greater than 0.9A, or greater than 1.4A.

When the cloth amount detection and judgment output are performed as shown in Table 1 and Table 2, the cloth amount detection can be simply performed with only one evaluation value. On the other hand, when the cloth amount detection and judgment output are performed as shown in Table 3, the cloth amount detection with better accuracy can be performed by making use of the characteristics of each evaluation value.

FIG. 13 is a timing diagram of the detection Iq and the rotation angle under the cloth amount detection of the washing machine in the first embodiment.

Figure 13 (a) shows the change of the specified number of revolutions (dotted line) and the actual number of revolutions (solid line) over time, and Figure 13 (b) shows the change of Iq (solid line) over time. There is an ON period formed by the acceleration control period and the constant speed control period, and an OFF period formed by the deceleration control period.

In the constant speed control of Figure 13 (b), the period from the cumulative operation delay time to the end of the constant speed control is the cumulative operation of Iq (the shaded part). The average Iq used for cloth quantity detection is calculated by the cumulative operation of Iq. Here, since Iq is easily affected by the change in the number of revolutions, the change is suppressed by measuring Iq after the cumulative operation delay time, and the deviation of the average Iq is also suppressed.

In the deceleration control of Figure 13 (a), the cumulative operation of the total rotation angle up to the minimum detected rotation number is performed (the shaded part). Since the rotation angle at low rotations where it is difficult to detect the rotation number is removed, the cumulative operation of the rotation angle is limited to the minimum detected rotation number to improve the accuracy of the cumulative operation of the rotation angle.

Although the figure only uses stirring in one direction at a time for determination, by changing the rotation direction and performing an even number of (for example, 4) accumulation operations on Iq and rotation angle, the influence of the rotation direction can be suppressed to improve the accuracy of the average Iq or the accumulated rotation angle.

FIG. 14 is a flow chart of the motor speed control process of the washing machine in the first embodiment.

The motor speed control process starts from step S600. In step S601, it is confirmed whether the motor rotation number ω is greater than the motor command rotation number ωs. If it is greater (yes), it proceeds to step S602. If it is equal or smaller (no), it proceeds to step S603. In step S602, the command δ axis current Iδs is reduced. In step S603, the command δ axis current Iδs is increased. In steps S601~S603, when the command δ axis current Iδs is set by the speed error amplifier 26, since the variable element is large and the control is unstable, proportional integral control with integral elements such as averaging is usually performed.

In step S604, the current control timer Te_tm is cleared to 0. In step S605, the current control processing routine is entered (details are described later). In step S606, the current control processing time (for example, 0.1ms) is added to the current control timer Te_tm. In step S607, it is confirmed whether the current control timer Te_tm is larger than the current control cycle Te_cycle. If it is larger (yes), it enters step S608. If it is the same or smaller (no), it enters step S605. In step S608, the motor speed control processing ends.

FIG. 15 is a flowchart of the motor stop control process of the washing machine in the first embodiment. The motor stop control process starts from step S700. In step S701, 0 or a fixed value is substituted into the command δ axis current Iδs. There are the following methods: a method of using 0 as the command δ axis current Iδs to avoid generating torque, a method of using a negative fixed value as the command δ axis current Iδs to generate a braking torque to shorten the braking time to the extent that the regenerative voltage does not become a problem, and a method of using a small positive fixed value as the command δ axis current Iδs to increase the difference in the accumulated calculated rotation angle by a small driving torque that can be stopped reliably due to the friction force acting in the direction of decelerating the rotation, so as to make it easier to judge when detecting the amount of cloth. Choose a method that is easy to use according to the amount of cloth or the structure of the washing machine.

Then, the same processing as steps S604 to S608 of the motor speed control processing shown in Figure 14 is performed. In step S702, the current control timer Te_tm is cleared to 0. In step S703, the current control processing routine is entered (details are described later). In step S704, the current control processing time (for example, 0.1ms) is added to the current control timer Te_tm. In step S705, it is confirmed whether the current control timer Te_tm is larger than the current control cycle Te_cycle. If it is larger (yes), it enters step S706. If it is the same or smaller (no), it enters step S703. In step S706, the motor stop control processing is terminated.

FIG. 16 is a flow chart of the motor current control process of the washing machine in the first embodiment.

The motor current control process starts from step S800. In step S801, the current detection unit 18 detects the phase currents Iu, Iv, and Iw. In step S802, it is confirmed whether any one of the phase currents Iu, Iv, and Iw is smaller than the phase current threshold I_limit. If it is smaller (yes), it proceeds to step S803. If it is the same or larger (no), it proceeds to step S804.

In step S803, the δ-axis current Iδ is calculated by the three-phase two-phase converter 22 in the manner of equation 1. In step S804, the process proceeds to "A" (see Figure 7). In step S805, it is confirmed whether the δ-axis current Iδ is larger than the command δ-axis current Iδs. If it is larger (yes), the process proceeds to step S806. If it is the same or smaller (no), the process proceeds to step S807. In step S806, the command δ-axis voltage Vδs is reduced. In step S807, the command δ-axis voltage Vδs is increased.

When the command δ-axis voltage Vδs is set by the Iδ error amplifier 23 in steps S805-S807, since the variable factor is large and the control is unstable, proportional integral control with integral factors such as averaging is usually performed.

Afterwards, similar to the δ axis, the voltage of the γ axis is calculated in steps S808~S811. In step S808, the γ axis current Iγ is calculated by the three-phase two-phase converter 22 in the manner of formula 1. In step S809, it is confirmed whether the γ axis current Iγ is larger than the commanded γ axis current Iγs. If it is larger (yes), it proceeds to step S810. If it is the same or smaller (no), it proceeds to step S811. In step S810, the commanded γ axis voltage Vγs is reduced. In step S811, the commanded γ axis voltage Vγs is increased. When the command γ-axis voltage Vγs is set by the Iγ error amplifier 24 in steps S809-S811, since the variable factor is large and the control is unstable, proportional integral control with integral factors such as averaging is usually performed.

In step S812, the applied voltages Vus, Vvs, and Vws are calculated by the two-phase or three-phase converter 25 in the manner of equation 2. In step S813, the voltage is applied to the motor 4 through the PWM control unit 19 and the commutation circuit 17. In step S814, the motor current control process is terminated.

(Second implementation form)

Although the structure is the same as the first embodiment, the cloth amount detection control of the washing machine in the second embodiment with different control content is explained using Figures 17 and 18. The Iq accumulation operation condition in the cloth amount detection constant speed control of the first embodiment is changed (step S307 shown in Figure 9).

FIG17 is a flowchart of the cloth amount detection constant speed control of the washing machine in the second embodiment. Step S307 of FIG9 is changed to step S307a.

In the modified step S307a, check whether the difference between the motor rotation number ω and the motor command rotation number ωs is smaller than the convergence rotation number ω_converge (for example, 10r/min) and whether it has completely converged. If it is larger or not completely converged (no), proceed to step S310. If it is smaller and has completely converged (yes), proceed to step S308.

FIG. 18 is a timing diagram of the detection Iq under cloth amount detection of the washing machine in the second embodiment.

Figure 18 (a) shows the change of the specified number of revolutions (dotted line) and the actual number of revolutions (solid line) over time, and Figure 18 (b) shows the change of Iq (solid line) over time. There is an ON period formed by the acceleration control period and the constant speed control period, and an OFF period formed by the deceleration control period.

The designated rotation number + convergence rotation number and the designated rotation number - convergence rotation number (the shaded area) of the constant speed control in Figure 18 (a) are set as the threshold value, and whether the inflection point of the current rotation number falls within the range is used to determine whether it is completely converged. Although the five inflection points (×) on the left side of the current rotation number are not within the threshold value, since the inflection points (○) after the sixth are within the threshold value, Iq can be measured and the accumulation operation can be started.

Since it falls within the threshold, the change in the number of revolutions is small. Since Iq is measured during this period when the change in the number of revolutions is small, the change in Iq is also small, and the deviation in the average Iq is suppressed.

The rest is the same as implementation form 1.

(Effects, etc.)

As described above, the washing machine in the first embodiment and the washing machine in the second embodiment are equipped with: a stirring blade, which is rotatably arranged in the washing and dewatering tank; a motor, which has a permanent magnet and a winding; a power supply circuit, which supplies current to the motor; and a current detection unit, which detects the current of the motor. In addition, it is equipped with: a transmission mechanism, which transmits the torque of the motor to the stirring blade; a rotation number control unit, which controls the motor to a predetermined rotation number; and a control unit, which performs a predetermined number of acceleration control, constant speed control, or stop control on the motor in sequence and alternately from left to right. In addition, the control unit is provided with a cloth amount detection unit, which detects the amount of laundry from the average current value during the constant speed control period or the rotation angle during the stop control period.

With this structure, the amount of cloth can be easily detected by measuring the average current value during constant speed control or the rotation angle during stop control.

Furthermore, the cloth amount detection unit may be configured to detect the amount of laundry from both the average current value during the constant speed control period and the rotation angle during the stop control period.

According to this structure, the amount of fabric can be detected from the rotation angle that changes greatly when the amount of fabric is small, and the amount of fabric can be detected from the average current that changes in the same way as when the amount of fabric is small when the amount of fabric is large, thereby being able to detect the amount of fabric with better accuracy.

Furthermore, the cloth amount detection unit may also be configured to detect the amount of laundry by using the average current value from a predetermined time after entering the constant speed control period to the end of the constant speed control period.

This structure can suppress the deviation of the average current value measured each time, and can easily detect the amount of fabric with better accuracy.

Furthermore, the cloth amount detection unit can also be configured to detect the amount of laundry by using the average current value from a predetermined time to the end of the constant speed control period after the target rotation speed and the current rotation speed completely converge to below a predetermined value during the constant speed control period.

With this configuration, the average current value can be calculated from a state where the cause of the deviation of the average current value measured each time, that is, the change in the number of rotations, has been suppressed, so the amount of fabric can be detected with better accuracy.

Furthermore, the cloth amount detection unit may also be configured to detect the amount of laundry from the rotation angle when the torque is set to 0 or constant during the suspension control period.

With this structure, since constant torque is continuously applied during the suspension control period, the deviation of the rotation angle caused by torque variation can be suppressed, and the amount of fabric can be easily detected with better accuracy. In addition, by allowing the PWM output to rotate inertially without completely shutting down the PWM output, the rotation angle can be detected even without a sensor.

In addition, the rotation angle from the start of the suspension control to the current rotation number reaching the predetermined rotation number can also be set to detect the amount of laundry.

With this configuration, the rotation angle is accumulated and calculated only in the high rotation area where the rotation number can be detected correctly, thereby being able to detect the amount of fabric with better accuracy.

In addition, the control unit can also be set to terminate the cloth amount detection when the motor current is above a preset value or the rotation angle is less than a preset value, considering the amount of laundry as the maximum.

With this configuration, since it is possible to know that the amount of fabric is large even without performing the entire fabric amount detection process, the time of the fabric amount detection process can be shortened or energy can be saved.

(Other implementation forms)

As described above, the first and second embodiments are described as examples of the technology disclosed in this disclosure. However, the technology disclosed in this disclosure is not limited to these.

Therefore, other implementation forms are exemplified below.

The first and second embodiments are described by taking a pulsator-type vertical washing machine as an example, in which a motor pulley 31 and an impeller pulley 32 are connected by a belt 5 and a speed reduction mechanism and clutch 6 are combined with a pulsator 1 or a washing and dewatering tank 2. However, even in a washing machine of a direct drive type in which the washing and dewatering tank and the motor are coaxial, the amount of cloth can be easily detected with good accuracy.

Furthermore, although the first and second embodiments are described using a pulsator-type upright washing machine as an example, the amount of cloth can be easily detected with good accuracy even in an agitator-type upright washing machine.

(Third implementation form)

The following describes the water flow correction control of the washing machine in the third embodiment.

In addition, the structure of the washing machine in the third embodiment is the same as that of the washing machine in the first embodiment shown in Figures 1 to 6A and 6B, and the same symbols are attached and the description is omitted.

In the above configuration, the water flow correction control of the washing machine in the third embodiment is described using Figures 19 to 27.

FIG. 19 is a flow chart of the water flow correction control of the washing machine in the third embodiment.

The water flow correction control starts from step S1100. In step S1101, the number of reversals n is cleared to 0. In step S1102, the motor command rotation number ωs is cleared to 0. In step S1103, the water flow correction acceleration control processing routine is entered (details are recorded later). In step S1104, the water flow correction constant speed control processing routine is entered (details are recorded later). In step S1105, the water flow correction deceleration control processing routine is entered (details are recorded later). In step S1106, the number of reversals n is added +1. In step S1107, check whether the number of reversals n is greater than the set judgment number ns (for example, 22 times). If it is greater (yes), enter step S1108, and if it is less than (no), enter step S1109. In step S1108, enter the water flow correction control judgment output processing routine (details are described later). In step S1109, if the rotation direction is CW, it is changed to CCW, and if it is CCW, it is changed to CW. Step S1110 is entered from "B" of other processing routines. In step S1111, input the maximum (for example, weak water flow) as the water flow correction control judgment value. In step S1112, end the water flow correction control.

FIG. 20 is a flow chart of the water flow correction acceleration control of the washing machine in the third embodiment.

Water flow correction acceleration control starts from step S1200. In step S1201, the motor acceleration α (for example, 3000 (r/min)/s) is called. In step S1202, the motor specified rotation number ωs is added according to the motor acceleration α. In step S1203, the motor speed control processing routine is entered (the details are described later). In step S1204, it is confirmed whether the motor specified rotation number ωs is greater than the motor command maximum rotation number ωmax (for example, 2160r/min). If it is greater (yes), it enters step S1205. If it is less than (no), it enters step S1201. In step S1205, the water flow correction acceleration control ends.

FIG. 21 is a flow chart of the water flow correction constant speed control of the washing machine in the third embodiment.

Start the water flow correction constant speed control from step S1300. Clear the ON time limit timer T_ontm to 0 in step S1301. Enter the motor speed control processing routine in step S1302 (details are described later). Add the motor speed control processing time (for example, 1ms) to the ON time limit timer T_ontm in step S1303. Check in step S1304 whether the ON time limit timer T_ontm is larger than the ON time limit T_on. If it is larger (yes), enter step S1305. If it is the same or smaller (no), enter step S1302. End the water flow correction constant speed control in step S1305.

FIG. 22 shows a flow chart of the water flow correction deceleration control of the washing machine in the third embodiment.

The water flow correction deceleration control starts from step S1400. In step S1401, it is confirmed whether the number of reversal times n is 0. If it is 0 (yes), it proceeds to step S1402. If it is not 0 (no), it proceeds to step S1404. In step S1402, the OFF time limit timer T_offtm is cleared to 0. In step S1403, the accumulated rotation angle θ_integral is cleared to 0. In step S1404, it proceeds to the motor speed stop control processing routine (details are described later). In step S1405, check whether the angle threshold θ_limit (later, the angle is set to the motor electrical angle) is greater than the motor rotation angle θ. If it is greater (yes), proceed to step S1406. If it is equal to or smaller (no), proceed to step S1407. In step S1406, add the motor stop control processing time (for example, 1ms) to the OFF time limit timer T_offtm. In step S1407, proceed to "B" (refer to Figure 19).

In step S1408, check whether the motor rotation number ω is smaller than the minimum detection rotation number ω_min (for example, 100r/min). If it is smaller (yes), proceed to step S1410. If it is equal to or larger (no), proceed to step S1409. In step S1409, add the motor rotation angle θ to the cumulative calculation rotation angle θ_integral. In step S1410, check whether the OFF time limit timer T_offtm is larger than the OFF time limit T_off. If it is larger (yes), proceed to step S1411. If it is equal to or smaller (no), proceed to step S1404. In step S1411, end the water flow correction deceleration control.

FIG. 23 is a relationship diagram between the cumulative calculation rotation angle of the judgment output of the water flow correction control of the washing machine in the third embodiment and the judgment water flow under the water flow correction control.

The points in Figure 23 are the evaluation values (accumulated rotation angles) of each water flow (e.g., weak water flow, slight water flow, standard water flow) at a certain water level, and the dotted line is an approximate line connecting these points. As shown by the arrow line, the threshold for judging each water flow judgment value (e.g., weak water flow, slight water flow, standard water flow at a water level of 65L) is determined from the evaluation value. This is performed multiple times under each water flow, and the threshold is set to take into account the deviation of the evaluation value.

Table 4 shows the water flow determined by the accumulated rotation angle output from the water flow correction control determination of the washing machine in the third embodiment.

As shown in Figure 23, since the cumulative operation rotation angle and the water flow correction control water flow judgment value are in an inversely proportional relationship, at a certain water level, although the change of the cumulative operation rotation angle is smaller under standard water flow, making the threshold value denser, the change of the cumulative operation rotation angle is larger under weak water flow and it is easier to reduce the threshold value. Based on this, the water flow correction control water flow judgment value such as Table 4 can be set from the cumulative operation rotation angle.

Table 5 shows the time limits of the determined water flow as an example. For example, the standard water flow is 1.4 seconds on/1.0 seconds off, the weak water flow is 1.0 seconds on/1.2 seconds off, and the weak water flow is 0.5 seconds on/1.2 seconds off.

FIG. 24 is a timing diagram of detecting the rotation angle under the water flow correction control of the washing machine in the third embodiment.

This graph shows the change in the specified number of revolutions (dotted line) and the actual number of revolutions (solid line) over time. There is an ON period formed by the acceleration control period and the constant speed control period, and an OFF period formed by the deceleration control period.

In addition, during deceleration control, the cumulative operation of the total rotation angle up to the minimum detected rotation number is performed (the shaded part). Since the rotation angle at low rotation numbers, which is difficult to detect, is removed, the cumulative operation of the rotation angle is limited to the minimum detected rotation number to improve the accuracy of the cumulative operation of the rotation angle.

Although the figure only uses stirring in one direction at a time for judgment, by changing the rotation direction and performing the accumulation operation an even number of times (for example, 22 times) based on the rotation angle, the influence of the rotation direction can be suppressed, thereby improving the accuracy of the average accumulation operation rotation angle.

FIG. 25 is a flowchart showing the motor speed control process of the washing machine in the third embodiment.

The motor speed control process starts from step S1500. In step S1501, it is confirmed whether the motor rotation number ω is greater than the motor command rotation number ωs. If it is greater (yes), it proceeds to step S1502. If it is equal or smaller (no), it proceeds to step S1503. In step S1502, the command δ axis current Iδs is reduced. In step S1503, the command δ axis current Iδs is increased. In steps S1501~S1503, when the command δ axis current Iδs is set by the speed error amplifier 26, since the variable element is large and the control is unstable, proportional integral control with integral elements such as averaging is usually performed.

In step S1504, the current control timer Te_tm is cleared to 0. In step S1505, the current control processing routine is entered (details are described later). In step S1506, the current control processing time (for example, 0.1ms) is added to the current control timer Te_tm. In step S1507, it is confirmed whether the current control timer Te_tm is larger than the current control cycle Te_cycle. If it is larger (yes), it enters step S1508. If it is the same or smaller (no), it enters step S1505. In step S1508, the motor speed control processing ends.

FIG. 26 is a flowchart of the motor stop control process of the washing machine in the third embodiment.

The motor stop control process starts from step S1600. In step S1601, 0 or a fixed value is substituted into the command δ axis current Iδs. There are the following methods: a method of using 0 as the command δ axis current Iδs to avoid generating torque, a method of using a negative fixed value as the command δ axis current Iδs to generate a braking torque to shorten the braking time to the extent that the regenerative voltage is not a problem, and a method of using a small positive fixed value as the command δ axis current Iδs to increase the difference in the accumulated rotation angle by a small driving torque that can be stopped reliably due to frictional force acting in the direction of decelerating the rotation, so as to make it easier to judge when detecting water splashes. Select the method that is easy to use according to the amount of cloth or the structure of the washing machine.

Then, the same processing as steps S1504 to S1508 of the motor speed control processing is performed. In step S1602, the current control timer Te_tm is cleared to 0. In step S1603, the current control processing routine is entered (details are described later). In step S1604, the current control processing time (for example, 0.1ms) is added to the current control timer Te_tm. In step S1605, it is confirmed whether the current control timer Te_tm is larger than the current control cycle Te_cycle. If it is larger (yes), it enters step S1606. If it is the same or smaller (no), it enters step S1603. In step S1606, the motor stop control processing is terminated.

FIG. 27 is a flow chart of the motor current control process of the washing machine in the third embodiment.

The motor current control process starts from step S1700. In step S1701, the current detection unit 18 detects the phase currents Iu, Iv, and Iw. In step S1702, the three-phase two-phase converter 22 calculates the δ-axis current Iδ in the manner of formula 1. In step S1703, it is confirmed whether the δ-axis current Iδ is larger than the command δ-axis current Iδs. If it is larger (yes), it proceeds to step S1704. If it is the same or smaller (no), it proceeds to step S1705. In step S1704, the command δ-axis voltage Vδs is reduced. In step S1705, the command δ-axis voltage Vδs is increased.

When the command δ-axis voltage Vδs is set by the Iδ error amplifier 23 in steps S1703 to S1705, since the variable factor is large and the control is unstable, proportional integral control with integral factors such as averaging is usually performed.

Afterwards, similarly to the δ-axis, the voltage of the γ-axis is calculated in steps S1706 to S1709. In step S1706, the γ-axis current Iγ is calculated by the three-phase two-phase converter 22 in the manner of formula 1. In step S1707, it is confirmed whether the γ-axis current Iγ is larger than the commanded γ-axis current Iγs. If it is larger (yes), the process proceeds to step S1708. If it is the same or smaller (no), the process proceeds to step S1709. In step S1708, the commanded γ-axis voltage Vγs is reduced. In step S1709, the commanded γ-axis voltage Vγs is increased. When the command γ-axis voltage Vγs is set by the Iγ error amplifier 24 in steps S1707-S1709, since the variable factor is large and the control is unstable, proportional integral control with integral factors such as averaging is usually performed.

In step S1710, the applied voltages Vus, Vvs, and Vws are calculated by the two-phase or three-phase converter 25 in the manner of equation 2. In step S1711, the voltage is applied to the motor 4 through the PWM control unit 19 and the commutation circuit 17. In step S1712, the motor current control process is terminated.

(Effects, etc.)

As described above, the washing machine in this embodiment is equipped with: a stirring blade, which is rotatably arranged in the washing and dehydrating tank; a motor, which has a permanent magnet and a winding; a power supply circuit, which supplies current to the motor; and a current detection unit, which detects the current of the motor. In addition, it is equipped with: a transmission mechanism, which transmits the torque of the motor to the stirring blade; a rotation number control unit, which controls the motor to a predetermined rotation number; and a control unit, which performs a predetermined number of acceleration control, constant speed control, or stop control on the motor in sequence and alternately from left to right. In addition, the control unit performs water flow correction control during washing in response to the rotation angle during the stop control period.

With this structure, when the rotation angle is large, it is predicted that washing water will splash, and the water flow is adjusted in advance to prevent splashing to control it. This ensures the cleaning performance while preventing washing water from splashing.

Furthermore, it is also possible to control the water flow correction control so that after entering the stop control period, the water flow for washing can be changed according to the rotation angle until the current rotation number reaches the predetermined rotation number.

With this structure, the rotation angle can be detected with higher accuracy, instead of detecting at low speeds where errors in the rotation angle are more likely to occur, and the rotation angle concentrated in the medium and high speed areas can be detected.

Furthermore, it can be set that in the water flow correction control, the water flow during washing can be changed according to the rotation angle from the start of the stop control to the end of the predetermined time.

With this structure, the rotation angle concentrated in the middle and high speed area can be detected, thereby easily detecting the rotation angle with better accuracy. The middle and high speed area is the middle and high speed area before the low speed where the rotation angle error is more likely to occur.

Furthermore, in the water flow correction control, the water flow during washing can be changed according to the rotation angle when the torque is set to 0 or constant during the suspension control period.

With this structure, since constant torque is continuously applied during the suspension control period, the deviation of the rotation angle caused by torque variation can be suppressed, and the water flow correction control can be performed with better accuracy. In addition, the rotation angle can be detected even without a sensor by allowing the PWM output to rotate inertially without completely shutting down the PWM output.

In addition, the control unit can also terminate the detection step of the water flow change during the water flow correction control when the rotation angle is greater than a predetermined value, and weaken the subsequent water flow.

With this structure, even if the water flow change detection step is not completed, it is still possible to predict that washing water will be scattered and weaken the water flow, thereby shortening the water flow change detection step time or achieving energy saving by shortening the time.

(Other implementation forms)

As described above, the third embodiment is described as an example of the technology disclosed in this disclosure. However, the technology in this disclosure is not limited to this.

Therefore, other implementation forms are exemplified below.

The third embodiment is explained by taking a pulsator-type vertical washing machine in which a motor pulley 31 and an impeller pulley 32 are connected by a belt 5 and a speed reduction mechanism and clutch 6 are combined with a pulsator 1 or a washing and dewatering tank 2. However, even in a washing machine of a direct drive type in which the washing and dewatering tank and the motor are coaxial, water flow correction control can be easily performed with better accuracy.

Furthermore, although the third embodiment is described using a pulsator-type upright washing machine as an example, even in an agitator-type upright washing machine, it is still possible to control the washing performance by using a normal water flow to a level that does not cause splashing, and in the case of splashing, the water flow is weakened to prevent splashing before it occurs.

Even without a position sensor, the present disclosure can still easily detect the amount of cloth with good accuracy. Specifically, the present disclosure can be applied to pulsator-type upright washing machines and agitator-type upright washing machines.

Furthermore, even without a position sensor, the present invention can still control the washing performance with a normal water flow without splashing, and in the case of splashing, the water flow is weakened to prevent splashing. Specifically, it can be applied to pulsator-type vertical washing machines and agitator-type vertical washing machines.

1: Pulsator (stirring blade)

2: Washing and dewatering sink

3: Water storage tank

4: Motor (electric motor)

5: Belt (transmission mechanism)

6: Speed reduction mechanism and clutch (transmission mechanism)

7: Gear motor

8: Brake belt

9: Washing machine frame

10: Panel section

11: Cover

12: Display unit

13: Control device

14: Water supply valve

15: Drain valve

31: Pulley (transmission mechanism)

32: Impeller pulley (transmission mechanism)

Claims (14)

A washing machine is characterized by: a stirring blade rotatably arranged in a washing and dehydrating tank; a motor having a permanent magnet and a winding; a power supply circuit for supplying current to the motor; a current detection unit for detecting the current of the motor; a transmission mechanism for transmitting the torque of the motor to the stirring blade; a rotation number control unit for controlling the motor to a predetermined rotation number; and a control unit for performing a predetermined number of acceleration control, constant speed control, or stop control on the motor in a left-right alternating manner, wherein the control unit is provided with a cloth amount detection unit, which detects the amount of laundry from the average current value during the constant speed control period or the rotation angle during the stop control period. As in claim 1, the cloth amount detection unit is configured to detect the amount of laundry from both the average current value during the constant speed control period and the rotation angle during the stop control period. As in claim 1 or 2, the cloth amount detection unit is configured to detect the amount of laundry by using the average current value from a predetermined time after entering the constant speed control period to the end of the constant speed control period. As in claim 1 or 2, the cloth amount detection unit is configured to detect the amount of laundry by using the average current value from a predetermined time to the end of the constant speed control period after the target rotation speed and the current rotation speed completely converge to below a predetermined value during the constant speed control period. A washing machine as claimed in claim 1 or 2, wherein the cloth amount detection unit is configured to detect the amount of laundry from the rotation angle when the torque is set to 0 or constant during the aforementioned stop control period. In the washing machine of claim 1 or 2, the cloth amount detection unit is configured to detect the amount of laundry based on the rotation angle from the start of the aforementioned stop control to the point when the current rotation number reaches the predetermined rotation number. As in claim 5, the washing machine, wherein the cloth amount detection unit is configured to detect the amount of laundry based on the rotation angle from the start of the aforementioned stop control to the point when the current rotation number reaches the predetermined rotation number. For example, in the washing machine of claim 1 or 2, the control unit is configured to terminate the cloth quantity detection by considering the amount of laundry as maximum when the motor current is above a predetermined value or the rotation angle is less than a predetermined value. A washing machine comprises: a stirring blade rotatably arranged in a washing and dehydrating tank; a motor having a permanent magnet and a winding; a power circuit for supplying current to the motor; a current detection unit for detecting the current of the motor; a transmission mechanism for transmitting the torque of the motor to the stirring blade; a rotation number control unit for controlling the motor to a predetermined rotation number; and a control unit for sequentially and alternately performing a predetermined number of acceleration control, constant speed control, or stop control on the motor, wherein the control unit is configured to perform water flow correction control during washing in response to the rotation angle during the stop control period. As in claim 9, the control unit is configured to change the water flow during washing in response to the rotation angle until the current rotation number reaches the predetermined rotation number after entering the stop control period in the water flow correction control. As in claim 9, the control unit is configured to change the water flow during washing in response to the rotation angle from the start of the stop control to the predetermined time in the water flow correction control. A washing machine as claimed in any one of claims 9 to 11, wherein the control unit is configured to change the water flow during washing in response to the rotation angle when the torque is set to 0 or constant during the stop control in the water flow correction control. A washing machine as claimed in any one of claims 9 to 11, wherein the control unit is configured to weaken the water flow when the rotation angle is greater than a predetermined value during the water flow correction control, thereby terminating the water flow change correction step. As in claim 12, the control unit is configured to weaken the water flow during the water flow correction control when the rotation angle is greater than a predetermined value, thereby terminating the water flow change correction step.