JPH11128587A - Washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce vibration and noises when an electromagnetic brake is put on by making a brushless motor revolve a stirrer and a revolving tub with the direct-drive system. SOLUTION: This washing machine is equipped with a revolving tub inside the outer tub and a stirrer inside the revolving basket. Three-phase brushless motor 20, which drives the stirrer or the stirrer and the revolving basket together, is provided as well. Switching elements 57a to 57f of inverter main circuit 47, switching element for discharge 50 and relay switch 46 are controlled as an electromagnetic brake device to the three-phase brushless motor 20. Microcomputer 63, which generates a regenerative brake, a discharge brake, a short- circuit brake and a soft brake, is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine having a stirrer and a brushless motor for rotating a rotary tub.

[0002]

2. Description of the Related Art In a washing machine, as is well known, a rotating tub as a washing tub and a dewatering basket is rotatably provided in an outer tub, and a stirrer is rotatable on the inner bottom of the rotating tub. It is provided in. The agitator and the rotary tank are configured to be driven to rotate by a brushless motor. In the case of this configuration, when the washing operation is performed, the rotation of the brushless motor is reduced and transmitted to the stirrer while the rotary tank is stopped with the brake stopped, and the rotation is driven forward and reverse. Further, when the spin-drying operation is performed, the brake of the rotary tub is released, and the rotation of the brushless motor is transmitted to the rotary tub and the agitator without deceleration, and both are driven to rotate at high speed.

[0003]

When the rotation of the brushless motor is stopped, the use of an electric electromagnetic brake has been considered because the mechanical brake cannot simplify the structure. However, the operation state of the brushless motor differs between the washing operation and the dehydrating operation, and the time when the brake is required is at the end time of each operation or in the middle. Therefore, in the single mode electromagnetic brake, the braking effect is low and the braking time is excessively long, and vibration or noise may be generated.

In particular, it has been considered that the agitator and the rotary tank are driven to rotate by a direct drive method by a brushless motor so as to reduce vibration and noise. Due to this, vibration and noise are generated, and even if the direct drive method is used to reduce the vibration and noise, the vibration and noise cannot be reduced by the brake, and the vibration and noise cannot be reduced. is there.

[0005] The concept of the direct drive system is as follows. In a washing machine, a gear reduction mechanism including a belt transmission mechanism, a clutch mechanism, and a planetary gear in a rotational force transmission path from the brushless motor to the rotation tub and the stirring body in order to rotationally drive the stirring body and the rotation tub. Etc. are provided. In this configuration, the weight of the entire washing machine increases, and the vertical dimension increases,
Also, considerable noise is generated when the gear reduction mechanism operates. As a countermeasure, when the agitator and the rotary tub are driven to rotate by a direct drive system by a brushless motor, a belt transmission mechanism and a gear reduction mechanism can be omitted, and the weight of the entire washing machine can be reduced. The vertical dimension can be reduced, and the operating noise of the gear can be eliminated.

The present invention has been made in view of the above circumstances, and has as its object to apply a brake to the rotation of a brushless motor as compared with a case where mechanical braking means is employed by employing an electromagnetic brake. An object of the present invention is to provide a washing machine that can contribute to simplification of the configuration, can always expect a good braking effect, and can also reduce vibration and noise during braking.

[0007]

According to a first aspect of the present invention, there is provided an inverter having a brushless motor for rotatingly driving a rotary tank and a stirring body, a DC power supply circuit, and a switching element connected in a multi-phase bridge. A drive circuit for driving the brushless motor, a regenerative brake means for regenerating an electromotive force of the brushless motor to the DC power supply circuit, and an input-side end of the inverter main circuit. And a short-circuit brake for short-circuiting the brushless motor winding.

In this configuration, a regenerative braking device, a discharging braking device, and a short-circuit braking device are provided as the electromagnetic braking device, so that the configuration can be simplified as compared with a case where a mechanical braking device is used. become. Each of these brake means has a different braking effect and a different degree of vibration / noise generation depending on the rotational speed of the motor when the brake is applied. In a washing machine, the time when a brake is required may be at the end of operation or during operation.However, the provision of the plurality of electromagnetic brakes makes it possible to use a single electromagnetic brake as compared with the case where a single electromagnetic brake is used. do it,
It is possible to expect an improvement in the braking effect and also to reduce vibration and noise during braking.

According to a second aspect of the present invention, there is provided an inverter main circuit including a brushless motor for rotatingly driving a rotary tank and a stirrer by a direct drive method, a DC power supply circuit, and a switching element connected in a multi-phase bridge. Drive means for driving the brushless motor, regenerative braking means for regenerating the electromotive force of the brushless motor to the DC power supply circuit, and disconnecting the DC power supply circuit and the inverter main circuit. And a short-circuit braking means for short-circuiting the brushless motor winding by discharging the electromotive force by means of a discharging element connected between both ends of the input side of the inverter main circuit.

In this configuration, since the rotary tank and the agitator are driven to rotate by the direct drive method, vibration and noise can be reduced. And as the electromagnetic braking means,
A regenerative braking device, a discharging braking device, and a short-circuit braking device are provided, so that the configuration can be simplified as compared with a case where a mechanical braking device is used. Each of these brake means has a different braking effect and a different degree of vibration / noise generation depending on the rotational speed of the motor when the brake is applied. In a washing machine, the time when a brake is required may be at the end of operation or during operation.However, the provision of the plurality of electromagnetic brakes makes it possible to use a single electromagnetic brake as compared with the case where a single electromagnetic brake is used. As a result, an improvement in the braking effect can be expected, and a reduction in vibration and noise at the time of braking can be expected, so that the vibration and noise of the entire washing machine can be effectively reduced.

According to a third aspect of the present invention, when the brake is applied to the brushless motor, one or two brake means are provided.
The feature is that two or more are combined.
The regenerative braking means is for regenerating the electromotive force of the brushless motor to the DC power supply circuit, which has an excellent braking effect when the motor rotation speed is relatively high, and can cope with the urgency of braking. On the other hand, it is not suitable for braking in a low rotational speed state, and if the motor electromotive force becomes excessive, circuit elements of the inverter main circuit and the DC power supply circuit may be damaged.

The discharge brake means consumes the electromotive force of the motor by a discharge element connected between both ends on the input side of the inverter main circuit in a state where the DC power supply circuit and the inverter main circuit are separated. An excellent braking effect is exhibited when the speed is high, and particularly when the regenerative braking means is executed, when the regenerative current is excessive, switching to the discharge brake is often performed. However, in this case, the temperature rises.

The short-circuit braking means can expect a braking effect from a high rotational speed state of the motor to a low rotational speed state when the motor is continuously used, and the braking effect is not small but not large. However, if this short-circuit braking means is used suddenly when the motor rotation speed is low, braking is suddenly applied, and vibration or noise due to vibration may be generated.

According to the third aspect of the present invention, when the brake is applied to the brushless motor, one or two or more braking means are combined, so that the braking effect is given priority or a good braking effect is obtained. It is possible to prevent a rise in temperature when applying a brake, prevent damage to circuit elements, and reduce vibration and noise.

[0015] The invention of claim 4 is characterized in that one or two or more brake means are combined according to the contents of the washing operation. In this configuration, it is possible to obtain a good braking effect, prevent a rise in temperature during braking, prevent circuit element damage, and reduce vibration and noise in accordance with the washing operation.

The invention of claim 5 is characterized in that when the regenerative braking means is executed, the short-circuit braking means is executed first. Executing the rotation brake means has an advantage that the braking effect is high when the motor rotation speed is high, but the regenerative current becomes excessively large, and there is a possibility that the circuit elements of the DC power supply circuit and the inverter main circuit may be damaged. However, when the regenerative braking means is executed, the short-circuit braking means is executed first,
Before the rotation brake means is executed, the electromotive force of the motor can be consumed by short-circuiting the motor windings, so that the regenerative current can be prevented from becoming excessively large when the regenerative brake means is executed. Also, it is possible to prevent circuit elements of the inverter main circuit from being damaged.

According to a sixth aspect of the present invention, there is provided a state in which the inverter main circuit is connected to the DC power supply circuit and is opened to the discharge element, and a state in which the inverter main circuit is opened from the DC power supply circuit and connected to the discharge element. When the regenerative braking means is executed, the short-circuit braking means and the discharge braking means are executed in advance, and when the short-circuit braking means is executed, the DC power supply circuit and the inverter main circuit are switched by the switching means. It is characterized in that the inverter main circuit is connected to the discharge element by opening the circuit. Executing the regenerative braking means has an advantage that the braking effect is high when the motor rotation speed is high, but the regenerative current becomes excessively large, and there is a possibility that circuit elements of the inverter main circuit and the DC power supply circuit may be damaged.
However, by executing the short-circuit brake means and the discharge brake means in this order prior to the execution of the regenerative braking, circuit element damage can be prevented. By the way, when the discharge brake means is executed, a potential difference may occur between the inverter main circuit and the DC power supply circuit due to the motor electromotive force. In this state, the switching means switches the inverter main circuit to the DC power supply. When switching between a state in which the switching circuit is connected and opened to the discharge element and a state in which the inverter main circuit is opened from the DC power supply circuit and connected to the discharge element, sparks are spattered or contact welding occurs when the switching means performs a switching operation. Or occur. In this case, in the above configuration, the switching operation is performed at the time of executing the short-circuit braking means in which no potential difference occurs between the DC power supply circuit and the inverter main circuit. Therefore, it is possible to prevent the occurrence of sparks and the occurrence of contact welding during the switching operation. Become.

The invention according to claim 7 is characterized in that the combination of the brake means in the washing operation and the dehydration operation is different. In this configuration, it is possible to obtain a good braking effect according to each of the washing operation and the dehydrating operation, to prevent a rise in temperature when applying braking, to prevent circuit element damage, and to reduce vibration and noise. Become.

The invention of claim 8 is characterized in that the combination of the brake means differs depending on the presence or absence of urgency when braking the brushless motor. When it is necessary to apply the brake, there are cases where urgency is required and cases where it is not so required. In case of urgency,
If a combination of braking means that has a high braking effect is favorable even if there is a temperature rise or vibration occurs, and if urgency is not required, a gentle braking effect may be used, so brakes that give priority to prevention of temperature rise and vibration generation A combination of means is preferred. However, in the above configuration, the combination of the braking means is made different depending on the presence or absence of urgency when applying a brake to the brushless motor. When there is no braking, it is possible to apply relatively gentle braking while effectively preventing temperature rise and vibration generation.

According to a ninth aspect of the present invention, a discharging element and a discharging switching element that operates in response to a motor induced voltage appearing in an inverter main circuit are connected in series, and a capacitor is connected in parallel with the series circuit. A discharge circuit having one end connected to the negative output terminal of the DC power supply circuit, a circuit closed between the positive output terminal of the DC power supply circuit and the positive input terminal of the inverter main circuit, and a positive terminal of the inverter main circuit. A first state in which a circuit is opened between the second input terminal and the other end of the discharge circuit, and a circuit in which a circuit is opened between the plus output terminal of the DC power supply circuit and the plus input terminal of the inverter main circuit, and Switching means for switching between a plus-side input terminal and a second state in which a circuit is closed between the other end of the discharge circuit; and Having said Rikae means was adapted to the second state.

When the brake is applied while the motor is rotating at a high speed, it is preferable that the motor is initially turned off to be free of rotation from the viewpoint of preventing vibration. In this case, an induced voltage is generated in the motor. If the motor induced voltage is large, it may adversely affect the inverter main circuit and the DC power supply circuit. At this time, it is preferable to execute the discharge brake means. Thus, in the above configuration, when executing the discharge brake means, the switching means is set to the second state. Then, the discharge switching element is turned on / off according to the motor induced voltage, and the electromotive force of the motor is consumed via the discharge element, so that the brake is applied.

Since the on / off operation of the discharge switching element is performed at a relatively high frequency, noise may be generated. However, in the above configuration, a capacitor is connected in parallel to a series circuit of the discharge element and the discharge switching element. Is connected, the occurrence of the noise can be suppressed. Even if a capacitor is fixedly connected between both input terminals of the inverter main circuit, noise can be reduced, but in this case, a large charge / discharge current always flows through this capacitor. Therefore, a capacitor having a larger capacity than the required capacitor is required. In this regard, in the above configuration, the switching means is the second
This capacitor is used only as the noise filter when the discharge element is used, that is, only when the discharge element is used, so that a large capacity is not required.

According to a tenth aspect of the present invention, the switching means is the first type.
Is characterized in that a charging resistor for charging the capacitor when in the state of is connected in series to the capacitor. When the switching means is in the first state, DC power is supplied from the DC power supply circuit to the inverter main circuit, and the motor is rotating according to the operating condition. When the operation is completed and the brake is applied, the switching means switches to the second state. In this case, the switching means is the first
In this state, the capacitor is charged via the charging resistor, and the positive output terminal of the DC power supply circuit and the discharge circuit are at the same potential. Therefore, the switching means switches to the second state. In this case, sparks do not fly or contact welding does not occur.

An eleventh aspect of the present invention is characterized in that a diode for discharging the charge of the capacitor to the DC power supply circuit side is connected in parallel with the charging resistor. In a situation where the switching means is in the first state and the motor is rotating, for example, if a power failure occurs or the power plug is unplugged, the output voltage of the DC power supply circuit gradually decreases. At this time, since the capacitor is charged, the capacitor terminal voltage relatively exceeds the output voltage of the DC power supply circuit, the diode turns on, and the capacitor charge is discharged to the DC power supply circuit via this diode. I will be.

At this time, the DC power supply circuit side and the discharge circuit side have substantially the same potential. Even if the switching means is switched to the second state in this state, the spark does not fly or the contact welding does not occur. In this case, it is suitable when the switching means is constituted by a relay switch which is switched to and held in the first state at a predetermined operating voltage and is brought into the second state at a predetermined operating voltage or less (including a power failure). When the power plug is removed, it is possible to contribute to the prevention of sparks and contact welding at the relay switch.

A twelfth aspect of the present invention is characterized in that the ON time period of the switching element is shifted at the timing when the phase current amplitudes of the brushless motor coincide with each other. At the timing when the phase current amplitudes of the brushless motor match, the on-time timing of the switching element corresponding to each phase of the inverter main circuit may be the same.
At this time, a large spike current flows through the inverter main circuit, and noise is generated. However, in the above configuration, the on-time zone of the switching element is shifted at the timing when the phase current amplitudes of the brushless motor coincide with each other, so that generation of a large spike current can be reduced and noise can be prevented. .

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a fully automatic washing machine will be described below with reference to the drawings. First, in FIG. 2 showing the entire configuration of a fully automatic washing machine, a water receiving tub 2 which is an outer tub for receiving dewatered water is elastically supported via an elastic suspension mechanism 3 in an outer box 1. Inside the water receiving tub 2, a rotary tub 4 which is also used as a washing tub and a dewatering basket is rotatably disposed. A stirring body 5 is rotatably disposed at the inner bottom of the rotating tank 4.

The rotary tank 4 has a substantially cylindrical tank main body 4a, an inner cylinder 4b provided inside the tank main body 4a for forming a water passage gap, and an upper end of the tank main body 4a. The balance ring 4c is provided. When the rotary tank 4 is driven to rotate, the water inside rises along the inner peripheral surface of the tank main body 4a by centrifugal force and passes through a dehydration hole (not shown) formed in the upper part of the tank main body 4a. It is configured to be discharged into the water receiving tank 2.

A drain port 6 is formed at the right end of the bottom of the water receiving tank 2 in FIG. 2, and the drain port 6 is provided with a drain valve 7 and a drain hose 8 is connected thereto. . The drain valve 7 is a valve that is opened and closed by a drain valve motor 9 (see FIG. 1) as a drain valve driving unit described later, and is a so-called motor type drain valve. The drain valve motor 9 is composed of, for example, a geared motor. Further, an auxiliary drain port 6 is provided at the left end of the bottom of the water receiving tank 2 in FIG.
The auxiliary drain port 6a is connected to a drain hose 8 via a connecting hose (not shown). The auxiliary drain port 6a is for draining water that has been dewatered from the upper portion and discharged into the water receiving tank 2 when the rotary tub 4 is dewatered and rotated.

As shown in FIG. 3, a mechanism base 10 is attached to the outer bottom of the water receiving tank 2. A shaft support cylinder 11 is formed at the center of the mechanism base 10 so as to extend in the vertical direction. This shaft support cylinder 1
Inside 1, a hollow tank shaft 12 is rotatably inserted and supported via bearings 13, 13. A stirring shaft 14 is rotatably inserted and supported inside the tank shaft 12 via bearings 15 and 15. The upper and lower ends of the stirring shaft 14 are
It protrudes from the tank shaft 12.

Further, the shaft support cylinder 11 of the mechanism base 10
Is fitted through a seal 16 into a through hole 2a formed in the center of the bottom of the water receiving tank 2. The seal 16 seals the space between the upper end of the shaft support cylinder 11 and the through hole 2a of the water receiving tank 2 in a watertight manner. Furthermore, the seal 16 is also provided between the outer peripheral surface of the tank shaft 12 and the upper end of the shaft support cylinder 11, and the space therebetween is sealed in a watertight manner. Further, a flange portion 12a is formed integrally with the upper end portion of the tank shaft 12. The rotary tank 4 is connected and fixed to the flange portion 12a via a tank receiving plate 17. Thereby, the rotary tank 4 is attached to the tank shaft 12 so as to rotate integrally. In addition, at the upper end of the stirring shaft 14, FIG.
As shown in FIG. 2, the stirrer 5 is fitted and screwed and fixed, so that the stirrer 5 is attached to the stirring shaft 14 so as to rotate integrally.

A drain cover 18 is attached to a portion between the center of the inner bottom of the water receiving tank 2 and the drain port 6 as shown in FIG. The drain cover 18 forms a drain passage 19 communicating from the through hole 4d provided at the bottom of the rotary tub 4 to the drain port 6. In the case of this configuration, when water is supplied into the rotary tank 4 with the drain valve 7 closed, water is stored in the rotary tank 4 and the drain passage 19. When the drain valve 7 is opened, the water in the rotary tank 4 is drained through the through hole 4d, the drain passage 19, the drain port 6, the drain valve 7, and the drain hose 8.

The mechanism base 1 at the outer bottom of the water receiving tank 2
0, for example, an outer rotor type brushless motor 20
Is provided. Specifically, as shown in FIG. 3, the stator 2 of the brushless motor 20 is
1 is concentric with the stirring shaft 14 so that a stepped screw 22
It is fastened and fixed. The stator 21 includes:
As shown in FIG. 4, the laminated core 23 and the upper bobbin 24
, A lower bobbin 25, and a winding 26 (see FIG. 3). The laminated core 23 is, as shown in FIG.
It is configured by connecting three unitary iron cores 23a having a substantially arc shape in an annular shape. In addition, the upper and lower bobbins 24, 25
Is made of plastic and has a laminated core 23
Are fitted from above and below. And
The winding 26 is wound around the fitted bobbins 24 and 25. The winding 26 includes three-phase windings 26u, 26v, and 26w, as shown in FIG.

On the other hand, the rotor 27 of the brushless motor 20
Is attached to the lower end of the stirring shaft 14 so as to rotate integrally therewith, as shown in FIG. Rotor 27
Is composed of a rotor housing 28, a rotor yoke 29, and a rotor magnet 30. Here, the rotor housing 28 is formed by, for example, aluminum die-casting, and has a boss portion 28a formed in the center portion and a magnet arrangement portion 28b formed in the outer peripheral portion. The lower end of the stirring shaft 14 is fitted and fixed in the boss 28a.

The magnet arrangement portion 28b has a horizontal portion and a vertical portion. The rotor yoke 29 is brought into contact with the inner surface of the vertical portion, and the rotor yoke 27 is fixed to the horizontal portion by screwing. . A plurality of rotor magnets 30 are mounted on the inner surface of the rotor yoke 27 by, for example, bonding. As shown in FIGS. 3 and 5, a large number of ribs 28 c are radially protruded from a portion of the upper surface of the peripheral portion of the rotor housing 28 facing the winding 26 of the stator 21.
Further, on the upper surface of the central portion of the rotor housing 28, a plurality of projections 28d are radially projected around the axis. The plurality of convex portions 28d constitute an engaging portion.

On the other hand, as shown in FIG. 3, the rotor magnet 3 of the rotor 27
As the rotor position detecting means for detecting the rotation position of 0, for example, three Hall ICs 31a, 31b and 31c (only 31a is shown in this figure, and 31a, 31b and 31 are shown in FIG. 1)
c is attached via a fixture 32. The Hall ICs 31a, 31b and 31c are shown in FIG.
As shown in (b), the position sensor signals Ha, Hb, Hc are arranged so as to be shifted by 120 degrees. The positional relationship between the Hall ICs 31a, 31b, and 31c is set so as to output high-level and low-level digital signals in synchronization with a certain phase of the induced voltage of each phase.

The lower end of the tank shaft 12 has a clutch 3
2 are provided. The clutch 32 is connected so that the rotor 27, the stirring shaft 14 and the tank shaft 12 rotate together during the dehydrating operation, and so that only the tank shaft 12 does not rotate integrally with the rotor 27 and the stirring shaft 14 during the washing operation. It has a function of switching between a mode in which connection is released. Hereinafter, the clutch 32 will be specifically described. First, as shown in FIG. 6, the clutch 32 includes a switching lever 33 having a rectangular frame shape, and a holder 34 disposed inside the switching lever 33.

The holder 34 is attached to the lower end of the tank shaft 12 so as to rotate integrally therewith. Specifically, as shown in FIG. 5, a pair of flat surface portions 12b, 12b are formed on the outer peripheral surface of the lower end portion of the tank shaft 12. A fitting hole 34a into which the lower end of the tank shaft 12 fits is formed in the center of the holder 34. A flat surface portion with which the flat surfaces 12b, 12b of the tank shaft 12 abut is formed on the inner surface of the fitting hole 34a. Also, the holder 34
The pivot recess 3 having a substantially semicircular cross section is provided on the outer surface of the left end in FIG.
4b is formed. In the case of the above configuration, the holder 34 is fixed to the tank shaft 12 by screwing in a state where the lower end of the tank shaft 12 is inserted and fitted into the fitting hole 34a of the holder 34. Further, for example, a wave washer 35 is provided between the holder 34 and the lower bearing 13. This wave washer 35 presses the lower bearing 13 upward.

On the other hand, as shown in FIGS. 5 and 6, the switching lever 33 is fitted with a holder 34 therein.
It is configured to rotate integrally with the holder 34 and the phase shaft 12. On the inner surface side of the base end portion 33a (the left end portion in FIG. 5) of the switching lever 33, a pivoting convex portion 33b (see FIG. 3) having a substantially semicircular cross section to be fitted with the pivoting concave portion 34b of the holder 34 is provided. Is formed. In this case, the switching lever 33 is configured to rotate in the vertical direction with the fitting portion between the pivotal projection 33b and the pivotal recess 34b as a pivot point.

As shown in FIGS. 5 and 6, a toggle spring 36 is provided between the switching lever 33 and the holder 34. By the spring force of the toggle spring 36, the switching lever 33 is held in a state where the switching lever 33 has been moved to an upper rotation position (see FIG. 2) or a state where it has been moved to a lower rotation position (see FIG. 7). It is configured to be held. Projections 33d and 33e are protrudingly provided at the upper and lower ends of the tip 33c of the switching lever 33. Also,
The operated portion 3 is provided on the outer surface of the tip portion 33c of the switching lever 33.
3f is protruded.

On the other hand, as shown in FIGS. 3 and 5, a concave portion 37 is formed on the lower surface of the central portion of the mechanical base 10, which is a stationary portion, so as to correspond to the convex portion 33d on the upper part of the switching lever 33. Have been. In the case of this configuration, the switching lever 3
When the rotating operation of the upper lever 3 is performed (see FIG. 2, in this case, during the washing operation), the convex portion 33 d of the switching lever 33 is fitted into the concave portion 37 of the mechanism base 10. Thereby, the tank shaft 12 and thus the rotary tank 4 are fixed to the mechanical base 10 which is a stationary part. In the fitting state between the concave portion 37 and the convex portion 33d, the connection is released so that only the tank shaft 12 does not rotate integrally with the rotor 27 and the stirring shaft 14.
In the case of this embodiment, the stirring shaft 14 and the stirring body 5 are directly driven to rotate by the brushless motor 20. still,
The rotor 27 and the stirring shaft 14 are originally connected so as to rotate integrally.

On the other hand, when the switching lever 33 pivots downward (see FIG. 7, in this case, during the spin-drying operation),
The lower protrusion 33e of the switching lever 33 is engaged between the plurality of protrusions 28d on the upper surface of the rotor housing 28. Thereby, the tank shaft 12 and the rotor 27 (and the stirring shaft 14) are connected so as to rotate integrally. In the case of this embodiment, the tank shaft 12, the rotary tank 4, the stirring shaft 14, and the stirring body 5
The brushless motor 20 is directly driven to rotate. As a result, the brushless motor 20 is configured to rotationally drive the stirrer 5 or the stirrer 5 and the rotary tank 4 by a direct drive method.

A control lever 38 is rotatably supported at the right end of the mechanism base 10 in FIG. As shown in FIG. 6, the distal end of the control lever 38 is bifurcated, and a downward inclined surface 38a is formed at one of the distal ends (rightward in FIG. 6). ,
At the other end (left side in FIG. 6), an upward inclined surface 38b is formed. In this case, when the control lever 38 is rotated in one direction by the drain valve motor 9 that drives the drain valve 7, the operated portion 33f of the switching lever 33 of the clutch 32 is lowered by the downward inclined surface 38a of the control lever 38. , The switching lever 33 is rotated downward, and the state shown in FIG. 7 is obtained. The state shown in FIG. 7 corresponds to the dehydration operation, and the drain valve 7 is open.

On the other hand, in the state of FIG.
Is turned off, the control lever 38 is rotated in the reverse direction by the spring force of the return spring of the drain valve 7, and the operated portion 33f of the switching lever 33 is moved upward by the upward inclined surface 38b of the control lever 38. When pressed, the switching lever 33 is pivoted upward to be in the state shown in FIG. The state of FIG. 2 corresponds to the washing operation, and the drain valve 7 is closed.

Next, the electrical configuration of the above-described fully automatic washing machine will be described with reference to FIG. In FIG. 1, both terminals of an AC power supply 39 are connected to an input terminal of a rectifier circuit 41 via a reactor 40 on one side. Rectifier circuit 41
The smoothing capacitors 42a and 42b are connected between the output terminals of the DC power supply circuit 43 which is a voltage doubler rectifier circuit from the smoothing capacitors 42a and 42b and the rectifier circuit 41.
Is configured. The DC power supply circuit 43 is, for example, 28
Outputs a DC voltage of 0V.

The positive power supply line 44a and the negative power supply line 44 which are output lines of the DC power supply circuit 43
A constant voltage circuit 45 that supplies a constant DC voltage to a microcomputer 63 and the like described later is connected between the terminals b. The output terminal 44A of the positive power supply line 44a of the DC power supply circuit 43 is connected to a relay switch 46 as a switching means.
Of the inverter main circuit 47 via the NO terminal (normally open terminal) and the COM terminal (common terminal)
The other end is connected to the input terminal 47A of the other DC line 47b of the inverter main circuit 47.

The above-mentioned relay switch 46 is connected to the above-mentioned NO.
Terminal and a COM terminal, and an NC terminal (normally closed terminal). The switching operation is performed by a relay driving circuit 46a.
When a relay coil (not shown) is energized, the COM terminal and N
It is configured such that the connection between the O terminal and the COM terminal is automatically closed (the second state) when the power is cut off. . In the state where the relay drive circuit 46a holds the first state, the first state is maintained until the output voltage of the DC power supply circuit 43 becomes 50 V or less. In the first state, the positive output terminal 44A of the DC power supply circuit 43
And the plus side input terminal 47A of the inverter main circuit 47 is closed, and the plus side input terminal 47A of the inverter main circuit 47 and the other end of the discharge circuit 48 described later are opened. In the second state, A circuit is opened between the plus side output terminal 44A of the DC power supply circuit 43 and the plus side input terminal 47A of the inverter main circuit 47 and a circuit is closed between the plus side input terminal 47A of the inverter main circuit 47 and the other end of the discharge circuit 48. It is supposed to.

A discharging circuit 48 as discharging means is connected between the NC terminal of the relay switch 46 and the negative input terminal 47B of the inverter main circuit 47.
The discharge circuit 48 is configured by connecting a discharge resistor 49 as a discharge element and a discharge switching element 50 in series. Further, a capacitor 51 (corresponding to a capacitor according to claim 8) is connected in parallel with the series circuit of the discharge resistor 49 and the discharge switching element 50. The control terminal (gate) of the switching element 50 is connected to a drive circuit 52 composed of, for example, a photocoupler.

A charging resistor 53 connected in series with a capacitor 51 is connected between the positive input terminal 47A of the inverter main circuit 47 and the discharging circuit 48. Further, a diode 54 is connected in parallel with the charging resistor 53. (Corresponding to a diode according to claim 10). A regenerative diode 55 is connected between the output terminal 44A of the DC power supply circuit 43 and the input terminal 47A of the inverter main circuit 47 in parallel between the COM terminal and the NO terminal of the relay switch 46. Further, a voltage dividing circuit 56 is provided as voltage detecting means for detecting the voltage of one DC line 47a of the inverter main circuit 47. The voltage detected by the voltage dividing detection circuit 56 is supplied to a microcomputer 63 described later.

The inverter main circuit 47 includes three-phase bridge-connected switching elements 57a to 57f made of, for example, IGBTs, and these switching elements 57a to 57f.
The free wheel diodes 58a to 58f are respectively connected in parallel to 57f. The output terminals 59u, 59v, 5
9w is a three-phase winding 26u of the brushless motor 20;
6v, 26w. The control terminals (gates) of the switching elements 57a to 57f of the inverter main circuit 47 are connected to a drive circuit 6 composed of, for example, a photocoupler.
Connected to 0. This drive circuit 60 is a PWM circuit 6
The switching elements 57a to 57f are controlled to be turned on and off under the control of a signal from the control signal No. 1.
The DC power supply circuit 43, the inverter main circuit 47, the drive circuit 60, and the PWM circuit 61 constitute a drive unit 62.

The PWM circuit 61 has a means for internally generating a triangular waveform signal of a predetermined frequency, and is provided with an energizing signal D given from a microcomputer 63 described below.
drive signals Vup, Vun, Vvp, Vvn, Vw to form a sinusoidal winding current based on u, Dv, Dw.
p and Vwn are formed and output to the drive circuit 60. The drive signals Vup and Vun are shown in FIG.
(D).

On the other hand, the Hall IC of the brushless motor 20
The position sensor signals Ha, Hb, Hc output from 31a, 31b, 31c are provided to the microcomputer 63. Further, the microcomputer 63 is configured to control the energization of the drain valve motor 9 that drives the drain valve 7 to open and close and the water supply valve 64 that supplies water into the rotary tank 4.

The microcomputer 63 includes a power failure detection signal from a power failure detection circuit 65 for detecting a power failure based on the voltage of the AC power supply 39, a water level detection signal from a water level sensor 66 for detecting a water level in the rotating tub 4, An open / close detection signal from a lid switch 68 for detecting the open / close state of a lid 67 (see FIG. 2) provided on the upper part of the outer box 1 and switch signals from various operation switches 69 provided on an operation panel (not shown) are received. It is configured as follows.

The microcomputer 63 has a function as drive control means for controlling the energization of the brushless motor 20, a function for controlling the overall operation of the fully automatic washing machine, and a function for generating an electromagnetic brake for the motor 20. A control program therefor and data necessary for executing the program are stored in a ROM provided therein. In this case, the microcomputer 63
The switching element 57 of the inverter main circuit 47 is used to generate a regenerative brake, a discharge brake, a short-circuit brake, and also a soft brake.
a to 57f, the discharge switching element 50, and the relay switch 46 are controlled. Next, the operation of each brake will be described.

Regenerative brake: winding 26u of motor 20,
The switching elements 57a to 57f are turned on and off in an energizing pattern in which the phases of the currents flowing through the respective phases are delayed with respect to the phases of the induced voltages generated at 26v and 26w, so that the motor energy is regenerated to the DC power supply circuit 43 side. This is a brake that generates regenerative braking that is regenerated through the use diode 55. Therefore, the microcomputer 63
And the regenerative diode 55 constitute a regenerative braking means.

The feature of this regenerative brake is that it exhibits an excellent braking effect when the rotation speed of the motor 20 is relatively high and can cope with the urgency of braking. On the other hand, the regenerative power is used for braking in a low rotation speed state. Is not suitable because
If the motor electromotive force becomes excessively large, circuit elements of the inverter main circuit 47 and the DC power supply circuit 43 are damaged.

Discharge brake: winding 26 u of motor 20,
The on / off control of the switching elements 57a to 57f is performed with an energizing pattern in which the current phase flowing through each phase is delayed with respect to the phase of the induced voltage generated at 26v and 26w, and the relay switch 46 is closed between the COM terminal and the NC terminal. When the voltage detected by the voltage dividing circuit 56 becomes equal to or higher than an upper limit predetermined voltage (a voltage indicating that the DC line 47a has become 400 V), the discharge switching element 5 is turned on.
This is a brake generated when 0 is turned on and the motor energy is consumed by the discharge resistor 49. in this case,
The detected voltage is lower than a predetermined voltage (DC line 47a is 35
When the voltage becomes equal to or less than 0 V, the discharge switching element 50 is turned off. Accordingly, the discharge brake means is constituted by the switching elements 57a to 57f and the switching element 50 for discharge control function of the microcomputer 63, the relay switch 46, the voltage dividing circuit 56, and the discharging circuit 48. That is, the discharge brake device operates according to the induced voltage of the motor 20 when the regenerative brake device is executed.

The feature of this discharge brake is that it exhibits an excellent braking effect when the rotation speed of the motor 20 is high, and can be switched to this discharge brake when the regenerative current is excessive when the regenerative braking means is executed. Many. However, in this case, the temperature rises.

Short-circuit brake: The lower three switching elements 57b, 57d, 57f of the switching elements 57a-57f of the inverter main circuit 47 are simultaneously turned on to short-circuit all the windings 26u, 26v, 26w of the motor 20. The brake is applied by setting the state.
Therefore, the microcomputer 63 constitutes a short-circuit braking means by the on / off control function of the switching elements 57a to 57f.

The feature of this short-circuit brake is that, if the rotational speed of the motor 20 is continuously used from a high rotational speed state, a braking effect can be expected until a low rotational speed state, and the braking effect is not small but not large. . However, if the short-circuit brake is suddenly applied while the rotation speed of the motor 20 is low, the braking is suddenly applied, and vibration or noise due to the vibration may be generated.

Soft brake: A brake that brakes by gradually reducing the input duty ratio to the output voltage of the DC power supply circuit 43 applied to the motor 20 to zero. Therefore, the microcomputer 63 constitutes a soft brake means by the on / off control function of the switching elements 57a to 57f. The feature of this soft brake is that the braking effect is moderate, but the vibration and noise are low,
It is particularly suitable for applying a brake when the rotation speed of the motor 20 is low.

In addition to the above-mentioned brake means, there are initial idle running means, normal idle running means, and positioning means as control means related to the brake. The initial idle running means is controlled by the microcomputer 63 by the switching elements 57a to 57a.
Turn off all 57f and run the motor 20 idle.
At this time, the rotation speed of the motor 20 is detected based on the position sensor signals Ha, Hb, Hc from the Hall ICs 31a, 31b, 31c. Usually, the idle running means is controlled by the microcomputer 63 by the switching element 57a.
５７57f are all turned off, and the motor 20 runs idle. At this time, the rotation speed is not detected.

The positioning means includes switching elements 57a-57 so as to rotate motor 20 at an extremely low speed.
The on / off control of f is performed, and since this positioning means is executed for a very short time (0.5 seconds) as shown in FIG. 11, the motor 20 can be regarded as being positioned in a stationary state.

When the brake is applied, the microcomputer 63 applies the brake by combining the above-described braking means. As shown in FIG. , A "normal brake" mode, a "strong brake" mode, an "emergency brake" mode, and a "wash brake" mode.

The "wash brake" mode is used when the operation is a washing operation, and is executed after the forward rotation and the reverse rotation as shown in FIG. 11, and is executed by the software as shown in FIG. The braking means is first executed for a predetermined time (from a predetermined duty ratio to zero), then the short-circuit braking means is executed until the rotation stops, and the positioning means is executed for a predetermined time (0.5 seconds). This "wash brake" mode is used during a washing operation.

The "weak brake" mode is a mode in which the lid 67 is opened when the power-off switch or the pause switch of the operation switches 69 is operated when the spin-drying operation has expired after the set spin-drying time has expired. When any of the conditions of opening (this is detected by the lid switch 68) is satisfied, and the initial idle running means (including rotation speed detection) is executed for 40 ms (millisecond), the motor 2
0 is 300 rpm. p. It is used when it is less than m. In the "weak brake" mode, the normal idle running means is switched to 400
ms, then the soft brake means is executed for a predetermined time (from a predetermined duty ratio to zero), and the short-circuit brake means is executed until the rotation stops.

The "normal brake" mode is when the spin-drying operation is completed normally after the set spin-drying time has expired, and the rotation speed of the motor 20 becomes 300 when the initial idle running means is executed.
r. p. m when the power switch or the pause switch of the operation switches 69 is operated, or when the lid 67 is opened (this is detected by the lid switch 68). Either condition is satisfied, and the rotation speed of the motor 20 at the time of executing the initial idle running means is 300 rpm. p. m or more to 600 r.
p. It is used when it is less than m. In the "normal brake" mode, the initial idle running means (including the rotation speed detection) is executed for 40 ms, and then the short-circuit braking means is executed until the motor 20 stops.

In the "strong brake" mode, the operation switch 6
9, when the power-off switch or the pause switch is operated, or when the lid 67 is opened (this is detected by the lid switch 68), and the initial idle running means Motor 20 during execution
Rotation speed of 600 r. p. m or more to 1000 r. p.
It is used when it is less than m. The rotation speed of the motor 20 during the dehydration operation is 900 r. p.
m, which is usually 900 r.m.
p. It does not greatly exceed m.

In the "strong braking" mode, the short-circuit braking means is executed for 400 ms following the execution of the initial idling means.
Next, the regenerative braking means including the execution of the discharging brake means is turned on at a rotational speed of 480 rpm. p. m, and the short-circuit braking means is executed until the rotation speed becomes zero (stop rotation).

The "emergency brake" mode is used when a power failure occurs during the spin-drying operation, irrespective of the motor rotation speed at that time. The "emergency brake" mode is used for the initial idle running means. Subsequent to the execution, the short-circuit braking means is executed for 400 ms, and then the regenerative braking means including the execution of the discharge braking means is rotated at 100 rpm
r. p. m, and the short-circuit braking means is executed until the rotation speed becomes zero (stop rotation).

The operation of the above configuration will be described together with the operation of the microcomputer 63. First, during the washing operation and the dehydration operation, the motor 20 is rotationally driven to rotate the stirring body 5 or to rotate the rotary tank 4.
The microcomputer 63 rotates the motor 20 based on the position sensor signals Ha, Hb, Hc.
The energization signals Du, Dv, and Dw represented by 8-bit data values for obtaining a predetermined rotation speed are formed (FIG. 8C).
reference). The PWM circuit 61 outputs the energization signals Du, Dv,
Based on Dw, drive signals Vup, Vun, Vvp, Vv
n, Vwp, Vwn (Vup and Vun are shown in FIG. 8)
(Shown in (d)).

As a result, for example, the output voltage of the U-phase
As shown in (e), the U-phase winding current becomes a sine wave as shown in FIG. A sine wave current is supplied to the other V and W phases in the same manner. However, each energizing signal D
u, Dv, and Dw are formed so as to be shifted by 121 degrees in electrical angle. The microcomputer 6
3 outputs the above-mentioned energization signals Du, Dv, Dw,
A signal Do for permitting / stopping the output is given to the PWM circuit 61. When this signal Po is "0", the drive signals Vup, Vun, Vvp, Vvn, Vw
p and Vwn are set to low level so that the switching element 57a
To 57f are turned off, and the motor 20 is turned off.

During the washing operation such as the detergent washing operation or the rinsing operation, the microcomputer 63 controls the stirrer 5 to rotate forward and backward as shown in FIG.
After the motor 20 is rotated in the forward direction, the brake is applied in the wash brake mode. After the motor 20 is rotated in the reverse direction, the brake is applied in the wash brake mode. In this case, as described above, in the wash brake mode, the soft brake means is first executed for a predetermined time (from a predetermined duty ratio to zero), then the short-circuit brake means is executed until the rotation stops, and the positioning means is turned on for a predetermined time. Run for a time (0.5 seconds). This "wash brake" mode is used during a washing operation. When the brake is applied to the agitator 5, if the short-circuit braking device is used suddenly, the brake is suddenly applied and the water splashing sound becomes loud. Therefore, as in the present embodiment, the soft braking device is executed before the short-circuit braking device is executed. Therefore, generation of a loud splashing sound can be prevented.

Next, at the time of the spin-drying operation, the microcomputer 63 controls the motor 20 to rotate the rotary tub 4.
When this dehydration operation is completed normally after the set dehydration time has expired, the brake is applied, but the rotation speed of the motor 20 becomes 30 at the end of the operation.
0r. p. If it is less than m, this is detected during execution of the initial free running means, and the "light brake" mode including the initial free running means is used. When the brake is applied in the "weak braking" mode, the switching element 57a
After the initial idle running means to turn off all 57f is executed,
Subsequently, the normal idle running means for turning off all the switching elements 57a to 57f is executed. During the execution of the normal idle running means, the microcomputer 63 determines that the relay drive circuit 46a cuts off the relay coil and the relay switch 46 is turned off. Is closed between the COM terminal and the NC terminal, and the supply of DC power to the inverter main circuit 47 is stopped.

Then, the switching elements 57a to 57f
The soft brake means for gradually reducing the on-duty ratio to zero is executed. In this case, the motor rotational speed immediately before the execution of the soft brake means is experimentally predicted to be a certain rotational speed. Therefore, in this soft brake means, the on-duty ratio can be experimentally determined. The on-duty ratio is gradually reduced to zero. Then, when the on-duty ratio becomes zero, the execution of the soft brake means is stopped, and 57b, 57d,
The short-circuit braking means for turning on 57f is executed. At this time, the rotation speed of the motor 20 becomes approximately 100 rpm. p. m. Therefore, even if the short-circuit brake means is executed, the rotation speed does not suddenly decrease, and the brake is smoothly performed, so that no vibration and noise are generated.

As described above, the "light braking" mode corresponds to one of the conditions when the power switch or the temporary stop switch is operated in the spin-drying operation and when the lid 67 is opened. And the rotation speed of the motor 20 is 300 r. p. It is used when it is less than m. In this case as well, no vibration or noise is generated. FIG. 13 shows how the rotational speed changes when a brake is applied in the “weak brake” mode.

The dehydration operation is performed at a motor rotation speed of 300.
r. p. When the engine is normally terminated in a state where it is equal to or more than m, the brake is applied by using the “normal brake” mode described above. In this case, the short-circuit braking means is executed following the initial idle running means of 40 ms. At the time of this execution 40
By 0 ms, the relay drive circuit 46a cuts off the relay coil and switches between the COM terminal and the NC terminal of the relay switch 46 to close the inverter main circuit 47.
Stop supplying DC power to the This short-circuit braking means is executed until the rotation stops, and stops in about 20 seconds. In this case, since the short-circuit braking means is executed when the rotation speed of the motor 20 is high, the braking effect is not high, but the generation of vibration and noise is small. When the dehydration operation is completed normally, there is no urgency of braking, so that braking can be applied with priority given to prevention of generation of vibration and noise.

The "ordinary brake" mode corresponds to one of the conditions when the power-off switch or the temporary stop switch is operated in the spin-drying operation, or when the lid 67 is opened. Is 300
r. p. Above-600 r. p. m
Used. In this case, although it is relatively urgent, the rotational speed is limited to 600 r.p.m. p. m, it does not take much time until the rotation of the motor 20 stops even in the "normal brake" mode, and the urgency in this case can be sufficiently coped with. Therefore, also in this case, the generation of vibration and noise is reduced.

Next, in the spin-drying operation, either of the conditions when the power-off switch or the temporary stop switch is operated or when the lid 67 is opened, and the rotation speed is 600 rpm. p. Above-1000 r. p.
If it is less than m, the "strong brake" mode is used. In this case, it is relatively urgent. Here, if the brake is applied in the above-mentioned “normal brake” mode, it takes a long time to stop the rotation because the rotation speed is high, and thus the “strong brake” mode is used. In the "strong braking" mode, after the initial idle running means is executed, the short-circuit braking means is executed in 400 ms.
6a turns off the relay coil and the C of the relay switch 46
Switching between the OM terminal and the NC terminal is performed. In other words, prior to the execution of the regenerative braking means,
The DC power supply circuit 43 is opened from the inverter main circuit 47 to connect the discharge circuit 48 (that is, connect the discharge resistor 49), and thereafter, the regenerative braking means is executed.

As described above, the regenerative braking means has an energizing pattern in which the current phase flowing through each phase is delayed with respect to the phase of the induced voltage generated in the windings 26u, 26v, 26w of the motor 20. Switching elements 57a-
57f is turned on / off to regenerate motor energy to the DC power supply circuit 43 via the regenerative diode 55. In this case, when the rotation speed of the motor 20 is high, the electromotive force of the motor 20 is high, and an induced voltage of about 600 V is generated. When the motor induced voltage appearing on the DC line 47a exceeds 400V, this is detected by the voltage dividing circuit 56, and the microcomputer 63
Is connected to the discharge switching element 50 via the drive circuit 52.
Turn on. As a result, when the motor energy is consumed by the discharge resistor 49 and the voltage of the DC line 47a drops to 350 V or less, the discharging switching element 50
Is turned off, but since the motor 20 is still rotating,
While the situation where the motor induced voltage exceeds 400 V continues, the discharge switching element 50 is repeatedly turned on and off.

When the motor induced voltage does not exceed 400 V, the motor energy is regenerated to the DC power supply circuit 43 via the regenerative diode 55. That is, the regenerative braking means is executed. This regenerative braking means has a motor rotation speed of 480.
r. p. m until it drops to m. That is, 48
0r. p. m, the switching elements 57a to 57a in the discharge brake means and the regenerative brake means.
The on / off pattern of the switching elements 57a to 7f
The lower three switching elements 57b, 5f of 57f
7d and 57f are switched to the pattern of turning on at the same time, and the short-circuit braking means is executed. This short-circuit braking means is executed until the rotation stops.

In the "strong braking" mode, when the rotation speed of the motor 20 is high and there is a relatively urgent need, a higher braking effect can be obtained as compared with the "normal braking" mode. As a result, the braking time can be reduced.

Next, when a power failure occurs during the dehydration operation,
The "emergency braking" mode is used regardless of the current rotational speed of the motor 20. This is because, as described above, the regenerative braking means including the execution of the discharge braking means is operated at a rotational speed of 100 r. p. This is different from the above-mentioned “strong brake” mode in that the process is executed until the pressure decreases to m. In this case, the regenerative braking means operates at a rotational speed of 100 r. p. m, the braking force is increased, the braking time is short, and it corresponds to the urgency of braking. FIG. 12 shows that the dehydration operation is performed when the motor rotation speed is, for example, 600 to 1000 r.p. p. It shows the rotation speed change state (brake application degree state) in each brake mode when the brake is applied in a state of less than m, and as can be seen from this figure, the "emergency brake" mode and the "strong brake" mode It can be seen that the braking time is shorter in the order of the "normal brake" mode.

On the other hand, in the "strong braking" mode and the "emergency braking" mode, the short-circuit braking means is executed prior to the execution of the regenerative braking means, whereby the DC power supply circuit 43 and the inverter main circuit are operated. 47 can be prevented from being damaged. That is, when the rotation brake means is executed, although the braking effect is high when the motor rotation speed is high, the regenerative current becomes excessively large, and the circuit elements of the DC power supply circuit 43 and the inverter main circuit 47 may be damaged. There is. However, in this embodiment, since the short-circuit braking means is executed prior to the execution of the regenerative braking means, the motor energy can be consumed by the short-circuit of the motor winding before the execution of the rotating braking means, and the regenerative braking means is executed when the regenerative braking means is executed It is possible to prevent the current from becoming excessively large, and to prevent circuit elements from being damaged.

The discharge brake means is arranged such that the motor main electromotive force is generated and the inverter main circuit 47 is connected to the DC power supply circuit 43.
When the discharge brake is executed, the relay switch 46 is connected to the inverter main circuit 47 to the DC power supply circuit 43 and the discharge resistor 4
When the inverter main circuit 47 is switched to the second state in which the inverter main circuit 47 is opened to the DC power supply circuit 43 and connected to the discharge resistor 49, the relay switch 4
Sparks fly or contact welding occurs in six parts. In this case, in the above embodiment, the DC power supply circuit 43
Since the switching operation is performed when the short-circuit braking means that does not generate a potential difference between the inverter and the inverter main circuit 47 is performed, the occurrence of sparks and the occurrence of contact welding during the switching operation can be prevented.

In the "strong braking" mode and the "emergency braking" mode, the discharge switching element 50 is turned on to execute the discharge braking means.
On-off operation is performed at a relatively high frequency until the voltage becomes lower than 0V. Although noise may be generated by this switching, in this embodiment, since the capacitor 51 is connected in parallel to the series circuit of the discharge resistor 49 and the discharge switching element 50, the generation of the noise is reduced. It can be suppressed.

Even if the capacitor 50 is fixedly connected between the input terminals 47A and 47B of the inverter main circuit 47, it is possible to contribute to the suppression of noise generation. Since a charge / discharge current flows, a capacitor having a larger capacity than the capacitor required as a noise filter is required. In this respect, in this embodiment, the capacitor 51 is used as a noise filter only when the changeover switch 46 is in the second state, that is, only when the discharge resistor 49 is used, so that a large capacity is not required. .

In the washing operation and the dehydration operation, when the relay switch 46 is in the above-described first state (the COM terminal and the NO terminal are closed), the DC power supply circuit 4
3 supplies DC power to the inverter main circuit 47, and the motor 20 rotates according to the operation status. When the operation is completed and the brake is applied, the relay switch 46 switches to the second state (the COM terminal and the NC terminal are closed). In this case, the relay switch 4
6 is in the first state, the capacitor 51 is charged via the charging resistor 53, and the positive output terminal 44A of the DC power supply circuit 43 and the discharge circuit 48 are at the same potential. When the switch 46 is switched to the second state, the spark does not fly or the contact welding does not occur.

When the motor 20 is rotating while the relay switch 46 is in the first state described above, for example, when a power failure occurs or the power plug is unplugged, the brake is applied in the "emergency brake" mode. . Then, in this case, the output voltage of the DC power supply circuit 43 gradually decreases. At this time, since the capacitor 51 is charged, the terminal voltage of the capacitor 51 relatively exceeds the output voltage of the DC power supply circuit 43, and the diode 54 turns on.
The charge of the capacitor 51 is discharged to the DC power supply circuit 43 via the diode 54. At this time, the DC power supply circuit 43 and the discharge circuit 48 have substantially the same potential. In this state, even if the relay switch 46 is switched to the second state during the braking in the "emergency braking" mode, the spark does not fly or the contact welding does not occur.

In this case, if the relay switch 46 is configured to automatically enter the second state below the predetermined operating voltage (50 V described above) as in the present embodiment, the relay switch 46 can be used even during times other than braking. When the switching is performed at the time of power failure or disconnection of the power plug, the relay switch 4
6 can contribute to the prevention of occurrence of sparks and contact welding.

Here, in the energization signals Du, Dv, and Dw, when the amplitude of the energization signal of each phase is the same (when the data value is the same), the electrical angle is formed to be shifted by, for example, 1 degree. I have. That is, the phase of the energization signal Dv is shifted from the energization signal Du by an electrical angle of 121 degrees, and the phase of the energization signal Dw is shifted from the energization signal Dv by an electrical angle of 121 degrees. This will be described in detail by taking, for example, the U phase and the W phase as examples. FIG. 14 shows the U phase,
The V-phase energization signals Du and Dv are shown in detail, and are represented by sine wave data represented by electrical angle data obtained by dividing one electrical angle by 360 and numerical data of “256” stages. The amplitude of the sinusoidal winding current of the corresponding phase is determined by the magnitude of the numerical data, and the amplitude (current value) of the winding current is determined by the switching current applied to the winding of the phase. It is determined by the time width for energizing the element (any of 57a to 57f). The energization timing is determined by the electrical angle data.

The U-phase and V-phase energization signal waveforms are normally shifted by 120 electrical degrees. The waveform in this case is as shown in FIG. 17 shown as a reference example. A portion where the amplitudes of the U-phase and W-phase winding currents are the same (current waveforms intersect) (FIG. 8)
(P portion of (f)) occurs at a portion Pk portion where the U-phase and V-phase energization signals Du and Dv cross as shown in FIG. At this time, if the energization signals Du and Dv overlap with the same numerical data at one electrical angle K as shown in FIG. 18, a large spike current may be generated and noise may be generated.

That is, focusing on the U-phase, the switching elements 57a and 57f are on, and the DC line 47a of the inverter main circuit 47 when the current amplitude flowing through the U-phase winding 26u is 2A (ampere). The current that flows through is as indicated by reference numeral i1 in FIG. In this state, when the switching element 57a changes from on to off, the current is increased as shown by reference numeral i2 in FIG.
26w → between collector and emitter of switching element 57f → flywheel diode 58b → motor winding 26
The winding current flows through the paths u and 26w. When the switching element 57a is turned on again, the flywheel diode 58b cannot block the current flowing through the switching element 57a during the reverse recovery time due to the accumulated charge due to the current flowing immediately before, and as shown in FIG. Flows through the DC line 47a. Similarly, when the ON changes of the switching element 57c overlap, a short-circuit current of 9 A flows.

When a sinusoidal current is applied to the windings 26u, 26v, 26w, the switching elements of each phase switch while the energization period is slightly different at each electrical angle. Considering the case where a current flows in the U phase and the V phase, the switching elements 57a and 57
c and 57f are turned on, and as described above, the DC is turned on at the timing when the switching element 57a is turned on from off and at the timing when the switching element 57c is turned on from off.
A short-circuit current flows through the line 47a. Here, when the current amplitudes of the U-phase and the U-phase match (when the current waveforms cross), as shown in FIG. 18, the energization signals Du and Dv of the electrical angle at that time match. , And the PWM-processed drive signals Vup and Vvp completely coincide with each other, and the ON timings of the switching element 57a and the switching element 57c become completely the same (see reference numerals x and y in FIG. 19). Then, a state occurs in which a short-circuit current flows through both of the flywheel diodes 58b and 58d at the same time, and a large spike current of about 15 A, which is about twice the normal value, flows. This spike current not only adversely affects the operation of the entire control circuit, but also affects the operation of household electrical appliances other than the washing machine. In particular, in a state where the rotation speed of the motor 20 is low, particularly when the positioning unit is executed in the washing operation,
The cycle of one degree of electrical angle is long, the time for which the short-circuit current overlaps is also long, and the noise disturbance is further increased.

In this embodiment, however, each energizing signal D
As shown in FIGS. 14 and 15, u, Dv, and Dw are formed so as to be shifted by 121 degrees in electrical angle, and the same electrical angle does not result in the same numerical data. In other words, as shown in FIG. Since the ON time periods of the switching elements at the timing when the phase current amplitudes of the motor 20 coincide with each other are shifted, short-circuit currents do not overlap, so that generation of a large spike current can be reduced and noise generation can be prevented. Be able to contribute. In particular, it is possible to effectively prevent noise from occurring when the positioning unit is executed. In addition,
The rotation drive from the brushless motor to the rotating tub and the stirring body need not be a direct method, and the rotation may be transmitted by rotation transmission means such as a belt transmission mechanism.

[0096]

As apparent from the above description, the present invention has the following effects. According to the invention of claim 1, regenerative braking means is provided as electromagnetic braking means,
Equipped with discharge brake means and short-circuit brake means, the structure can be simplified as compared with the case of using mechanical brake means, and moreover, compared with the case of using a single electromagnetic brake means. Thus, it is possible to expect an improvement in the braking effect and also to reduce the vibration and noise during braking.

According to the second aspect of the present invention, the electromagnetic brake means includes regenerative brake means, discharge brake means,
It has a short-circuit braking means, which can simplify the configuration as compared with the case of using a mechanical braking means, and further improves the braking effect as compared with the case of using a single electromagnetic braking means. And the vibration and noise during braking can be expected to be reduced, and in addition to the direct drive of the rotary tank and the agitator, it can greatly contribute to the reduction of vibration and noise. According to the invention of claim 3, when the brake is applied to the brushless motor, the brake means is set to 1
One or two or more are combined, so it is possible to prioritize the braking effect, prevent a rise in temperature when applying braking while obtaining a good braking effect, prevent damage to circuit elements, and reduce vibration and noise. It becomes possible.

According to the fourth aspect of the present invention, one or two or more braking means are combined according to the contents of the washing operation, so that a good braking effect or braking can be obtained according to the contents of the washing operation. Temperature rise, circuit element damage prevention, vibration and noise reduction can be achieved.

According to the fifth aspect of the present invention, when the regenerative braking means is executed, the short-circuit braking means is executed first, so that before the rotation braking means is executed,
Motor energy can be consumed by short-circuiting of the motor windings, regenerative current can be prevented from becoming excessively large when regenerative braking means is executed, and damage to circuit elements of a DC power supply circuit and an inverter main circuit can be prevented. .

According to the sixth aspect of the present invention, a state where the inverter main circuit is connected to the DC power supply circuit and the discharge element is open, and a state where the inverter main circuit is open from the DC power supply circuit and is connected to the discharge element. When switching means for switching between and is provided and the regenerative braking means is executed,
Since the short-circuit brake means and the discharge brake means were executed in advance, and the short-circuit brake means was executed, the switching means opened the DC power supply circuit and the inverter main circuit to connect the inverter main circuit to the discharge element. Circuit elements can be prevented from being damaged, and the switching operation is performed when the short-circuit braking means that does not generate a potential difference between the DC power supply circuit and the inverter main circuit. Therefore, it is possible to prevent sparking and contact welding during the switching operation. .

According to the seventh aspect of the present invention, the combination of the brake means in the washing operation and the dehydration operation is different, so that the braking effect is prioritized in accordance with each of the washing operation and the dehydration operation, or a good braking effect is obtained. In addition, it is possible to prevent a rise in temperature when applying braking, prevent damage to circuit elements, and reduce vibration and noise.

According to the eighth aspect of the present invention, the combination of the braking means differs depending on the presence or absence of urgency when the brake is applied to the brushless motor. When there is no urgency, relatively gentle braking can be applied while effectively preventing temperature rise and vibration generation.

According to the ninth aspect of the present invention, when the discharge braking means is executed, it is possible to suppress the generation of noise when the discharge switching element of the discharge circuit operates.
The capacity of the noise prevention capacitor does not need to be increased.
According to the tenth aspect of the present invention, the charging resistor for charging the capacitor is connected in series with the capacitor, so that when the switching means performs the switching operation, the spark does not fly or the contact welding does not occur. According to the invention of claim 11, since a diode for discharging the electric charge of the capacitor to the DC power supply circuit side is connected in parallel with the charging resistor, for example, in the situation where the motor is rotating, there is a power failure,
Even if the switching means performs the switching operation due to the removal of the power plug, the spark does not fly or the contact welding does not occur.

According to the twelfth aspect of the present invention, the on-time period of the switching element is shifted at the timing when the phase current amplitudes of the brushless motor coincide with each other, so that generation of a large spike current can be reduced and noise generation can be prevented. Can contribute.

[Brief description of the drawings]

FIG. 1 is an electrical configuration diagram of a fully automatic washing machine showing one embodiment of the present invention.

FIG. 2 is a vertical side view of a fully automatic washing machine.

FIG. 3 is a longitudinal sectional side view of a drive mechanism of a stirring body and a rotary tank.

FIG. 4 is an exploded perspective view of a stator of the brushless motor.

FIG. 5 is an exploded perspective view of a brushless motor and a clutch.

FIG. 6 is a perspective view of a clutch and a control lever.

FIG. 7 is a view corresponding to FIG. 3, showing different switching states of the clutch.

FIG. 8 is a time chart when a sine wave is supplied to the brushless motor.

FIG. 9 is a diagram showing the contents of a brake mode.

FIG. 10 is a diagram showing the contents of use in a brake mode.

FIG. 11 is a diagram showing a change in rotation speed of a motor during a washing operation.

FIG. 12 is a diagram showing a change state of a rotation speed of a motor during a spin-drying operation in each brake mode.

FIG. 13 is a diagram showing a change state of a rotation speed of a motor during a spin-drying operation in another brake mode.

FIG. 14 is a diagram partially showing U-phase and V-phase energization signals;

FIG. 15 is a diagram showing a specific portion of an energization signal.

FIG. 16 is a diagram showing the on / off status of a switching element and a change in DC line current.

FIG. 17 is a diagram partially showing U-phase and V-phase energization signals showing a reference example;

FIG. 18 is a diagram corresponding to FIG. 15;

FIG. 19 is a diagram corresponding to FIG. 16;

FIG. 20 is a diagram showing a state of a current caused by turning on / off a switching element.

[Explanation of symbols]

1 is an outer box, 2 is a water receiving tank (outer tank), 4 is a rotary tank, 5 is a stirrer, 12 is a tank shaft, 14 is a stirring shaft, 20 is a brushless motor, 21 is a stator, 26 is a winding, and 27 is Rotor, 30
Is a rotor magnet, 32 is a clutch, 33 is a switching lever, 38 is a control lever, 47 is an inverter main circuit, 48
Is a discharge circuit, 49 is a discharge resistor (discharge element), 50 is a discharge switching element, 51 is a capacitor, 53 is a charge resistor, 54 is a diode, 55 is a regenerative diode, 57
a to 57f are switching elements, 60 is a drive circuit, 61
Indicates a PWM circuit, 62 indicates a driving unit, and 63 indicates a microcomputer.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Yoshiyuki Makino 2-33-10 Meishi, Nishi-ku, Nagoya-shi Toshiba Abu E Co., Ltd. Nagoya Office (72) Inventor Satoru Matsumoto Meishi-nishi, Nishi-ku, Nagoya Chome 33-10 Toshiba Abu E Co., Ltd. Nagoya Office

Claims (12)

[Claims] 1. A brushless motor for rotatingly driving a rotary tank and a stirrer, and an inverter main circuit having a DC power supply circuit and a switching element connected in a plural-phase bridge connection, Driving means for driving the brushless motor; regenerative braking means for regenerating the electromotive force of the brushless motor to the DC power supply circuit; and a discharge element connected between both ends on the input side of the inverter main circuit. A washing machine comprising: discharge brake means to be consumed; and short-circuit brake means to short-circuit the brushless motor winding. 2. A brushless motor for rotationally driving a rotary tank and a stirring body by a direct drive method, and an inverter main circuit having a DC power supply circuit and a switching element connected in a plural-phase bridge. A driving unit configured to drive the brushless motor; a regenerative brake unit configured to regenerate an electromotive force of the brushless motor to the DC power supply circuit; and a discharge element connected between both ends on the input side of the inverter main circuit. A washing machine comprising: discharge brake means for consuming the electromotive force; and short-circuit brake means for short-circuiting the brushless motor winding. 3. The washing machine according to claim 1, wherein when the brake is applied to the brushless motor, one or two or more brake means are combined. 4. The washing machine according to claim 3, wherein one or two or more brake means are combined according to the contents of the washing operation. 5. The washing machine according to claim 3, wherein when the regenerative braking means is executed, the short-circuit braking means is executed first. 6. A switching means for switching between a state in which the inverter main circuit is connected to the DC power supply circuit and opened to the discharge element, and a state in which the inverter main circuit is opened from the DC power supply circuit and connected to the discharge element. When the regenerative braking means is to be executed, the short-circuit braking means and the discharge braking means are executed first in advance, and when the short-circuit braking means is executed, the switching means opens the DC power supply circuit and the inverter main circuit to open the inverter main circuit. 4. The washing machine according to claim 1, wherein the circuit is connected to a discharge element. 7. The washing machine according to claim 4, wherein a combination of brake means in the washing operation and the dehydration operation is different. 8. The washing machine according to claim 3, wherein the combination of the brake means differs depending on the presence or absence of urgency when the brake is applied to the brushless motor. 9. A discharging element and a discharging switching element that operates in response to a motor induced voltage appearing in an inverter main circuit are connected in series, and a capacitor is connected in parallel with the series circuit. A discharge circuit connected to the negative output terminal of the DC power supply circuit, a circuit between the positive output terminal of the DC power supply circuit and the positive input terminal of the inverter main circuit, and a positive input terminal of the inverter main circuit and A first state in which a circuit is opened between the other end of the discharge circuit, and a circuit in which a circuit is opened between a positive output terminal of the DC power supply circuit and a positive input terminal of the inverter main circuit and a positive input terminal of the inverter main circuit. Switching means for switching between a second state in which the circuit is closed with the other end of the discharge circuit; and Washing machine according to claim 1, wherein it has such a state. 10. The washing machine according to claim 9, wherein a charging resistor for charging the capacitor when the switching means is in the first state is connected in series to the capacitor. 11. The washing machine according to claim 10, wherein a diode for discharging the electric charge of the capacitor to the DC power supply circuit side is connected in parallel with the charging resistor. 12. The washing machine according to claim 1, wherein the ON time period of the switching element is shifted at a timing when the phase current amplitudes of the brushless motor match.