JP2001246192A - Drum type washing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drum type washing machine which enables washing to be peeled off in a short time, prevents a motor from being damaged and noises from generating, and can save power. SOLUTION: This drum type washing machine is equipped with a cylindrical drum 5 with bottom rotatably supported and into which washing is thrown, a motor 55 to be directly connected to the drum 5 and to drive rotation of the drum 5, and a brake means to electrically brake the motor 55. Processes of washing, rinsing, dehydrating, and drying are suceedingly executed. A peeling process to peel washing off the inner wall of the drum 55 by braking with the brake means after rotating the drum 5 with the motor 55 in a prescribed number of revolution for a prescribed time is executed before the processes of dehydrating and drying.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum type washing machine having a rotating drum, and more particularly to a drum type washing machine capable of drying laundry.

[0002]

2. Description of the Related Art A conventional drum type washing machine is shown in FIGS.
It is configured as shown in FIG. FIG. 13 is a side sectional view, and FIG. 14 is a front view. Inside the outer casing 1 of the drum type washing machine, a water tub 4 having an opening 4a on the front surface is provided horizontally. The water tank 4 is suspended by a suspension device 7 and is elastically supported.

[0003] A drum 5 is coaxially arranged in the water tank 4.
The shaft 5e of the drum 5 is rotatably supported by a bearing 31. A pulley 32 is attached to the shaft 5 e of the drum 5, the rotation of a motor 34 is transmitted by a belt 33, and the drum 5 is driven to rotate.

[0004] The front surface of the body exterior 1 is openable and closable by an opening / closing door 3 so that laundry can be taken in and out of the drum 5. When the door 3 is closed, the opening 4a is sealed by a packing 10 made of rubber or the like provided around the opening 4a. A large number of small holes 5 a are formed on the peripheral surface of the drum 5 so that the washing liquid can flow between the water tub 4 and the drum 5.

[0005] A baffle 5b is protruded from the inner surface of the drum 5, and the laundry is hooked and lifted by the rotation of the drum 5,
Washing is performed by dropping in washing liquid. In addition, a balance weight 28 having a large mass is installed on the peripheral surface and the front surface of the water tank 4 so as to suppress vibration during high-speed rotation of the drum 5.

[0006] A water supply pipe 12 connected to a water pipe is provided in an upper portion of the exterior body 1. When the water supply valve 13 provided in the middle of the water supply pipe 12 is opened, water is supplied into the water tank 4 from a water supply nozzle 15 provided on the front surface of the water tank 4. A drain 4d for draining the washing water in the water tub 4 is provided at a lower portion of the water tub 4, and is drained by driving a drain pump 18.

On the side of the water tank 4, a drying duct 27 connecting the upper part and the lower part of the water tank 4 is provided. A drying unit 24 for sending warm air into the drum 5 is provided in the middle of the path of the drying duct 27, and the laundry is dried by the warm air sent into the drum 5.

[0008] In the drum type washing machine having the above-described structure, when the detergent and the laundry are put in the drum 5 and the opening / closing door 3 is closed, a “washing step” is executed. In the “washing process”, first, water is supplied from the water supply nozzle 15 and the drum 5 is driven by the motor 34.
Rotates forward and backward. The laundry is immersed in the lower part of the water tub 4, is caught by the baffle 5b, is carried upward, and falls. Cleaning is performed by the impact at this time.

After a predetermined washing time has elapsed, a "rinsing step" is subsequently performed. In the “rinsing step”, the washing water is drained from the drain port 4 d by driving the drain pump 18. Next, similarly to the “washing process”, water is supplied from the water supply nozzle 15, and the drum 5 is rotated by driving the motor 34. Thereby, rinsing is performed. During the rinsing step, a rinsing dewatering operation may be performed in which the drum 5 is rotated at a high speed after draining and the detergent is removed by centrifugal force.

After a predetermined rinsing time has elapsed, a "dehydration step" is subsequently performed. In the "dehydration step", the washing water is drained from the drain port 4d by driving the drain pump 18. Next, the drum 5 rotates at high speed, and the washing water contained in the laundry is discharged by centrifugal force.

When a predetermined dehydration time has elapsed, a "drying step" is executed. In the “drying process”, the drying unit 2
By 4, warm air is sent into the drum 5. This warm air is
The water contained in the laundry is absorbed and discharged from below the water tub 4. After being dehumidified by a cooler (not shown) provided in the drying duct 27, the drying unit 2
4 allows hot air to be sent into the water tank 4. This operation is repeatedly performed to dry the laundry.

In the "dehydration step", the laundry adheres to the inner wall of the drum 5 due to centrifugal force. Therefore, if the "drying step" is performed as it is, the laundry is dried with wrinkles. Therefore, the “peeling step” of peeling the laundry stuck to the inner wall of the drum 5 is performed before the “drying step”.

The operation of the "peeling step" is described in Japanese Patent No. 28959.
No. 48. According to the patent, the motor 34
By repeatedly performing the normal rotation and the reverse rotation of the drum 5, the drum 5 is rotated in the normal and reverse directions, and the laundry stuck to the inner wall of the drum 5 is peeled off. Thereby, the laundry is dried without wrinkles.

[0014]

However, according to the above-mentioned conventional drum type washing machine, in the "peeling step",
The motor 34 repeats normal rotation and reverse rotation. At this time, the motor 3
The drum 4 and the drum 5 are connected by a belt 33 and a pulley 32, and the belt 33 is stretched, and the friction between the motor 34 and the pulley 32 and the belt 33 is generated.

As a result, the rising and falling of the rotation of the drum 5 becomes slower with respect to the rotation of the motor 34, so that even if the rotation is reversed from the normal rotation to the reverse rotation, a large force is not applied to the laundry, and the laundry is sufficiently released from the drum 5. May not be peeled. For this reason, it is necessary to increase the number of rotations of the drum 5 in the normal rotation and the reverse rotation to secure the force by the reversal applied to the laundry.

As a result, the "peeling step" takes a long time,
There is a problem that power consumption increases. The motor 34
Is rapidly reversed from normal rotation at a large number of rotations.
4 may be damaged and noise may be generated.

It is an object of the present invention to provide a drum type washing machine capable of separating laundry in a short time, preventing motor damage and noise, and saving power.

[0018]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a bottomed cylindrical drum rotatably supported and into which laundry is put, and a drum directly connected to the drum and having the drum. A drum-type washing machine comprising a motor that rotates and a braking unit that electrically brakes the motor, and sequentially performs a washing step, a rinsing step, a dehydrating step, and a drying step by rotating the drum; After the drum is rotated at a predetermined number of revolutions for a predetermined time, a peeling step of breaking the laundry from the inner wall of the drum by braking by the braking means is performed after the dewatering step and before the drying step. And

According to this configuration, the drum is rotated by the drive of the motor directly connected to the drum to perform a washing step, a rinsing step, a dehydrating step, and a drying step, and wash and dry the laundry put in the drum. . At this time, after the spin-drying step, the drum is rotated for a predetermined time and then electrically braked, so that the laundry adhered to the inner wall of the drum by high-speed rotation is peeled off, and then the drying step is executed.

According to the present invention, in the drum type washing machine having the above structure, the motor comprises a DC brushless motor having an exciting winding, and an inverter circuit for converting a rectified power supply voltage into a driving voltage of the DC brushless motor. It is characterized by having. According to this configuration, the AC voltage of the commercial power supply is supplied to the inverter circuit after rectification, and is converted by the inverter circuit to supply the drive voltage to the DC brushless motor.

Further, according to the present invention, in the drum type washing machine having the above structure, before the braking of the motor by the braking means,
It is characterized in that a period in which the driving power of the motor is cut off and the motor rotates by inertia is provided. According to this configuration, after the spin-drying step, the driving power of the motor is cut off and the motor rotates by inertia for a predetermined period, and thereafter, the peeling step is executed.

Further, the present invention is characterized in that, in the drum-type washing machine having the above-described configuration, the braking means short-circuits the exciting winding in a state where the driving power of the motor is cut off. According to this configuration, the electromotive force generated by the motor that rotates by inertia when the drive power is cut off is:
It is consumed by the resistance of the short-circuited exciting winding, and a braking force is generated.

The present invention also relates to the drum-type washing machine having the above configuration, wherein the braking means performs regenerative braking on an electromotive force generated from the motor that rotates by inertia while the driving power of the motor is cut off. Features. According to this configuration, the electromotive force generated by the motor that rotates by inertia when the drive power is cut off is regenerated to the power supply, and a braking force is generated.

The present invention also provides a drum type washing machine having the above-mentioned structure, wherein when the rotation speed of the drum rotating by inertia becomes lower than a predetermined rotation speed before the dehydrating step is completed, the braking means is used. The motor is braked. According to this configuration, after the drum that rotates by inertia is electrically braked before the end of the spin-drying process, the peeling process is performed.

Further, the present invention is characterized in that in the drum-type washing machine having the above-mentioned structure, a braking condition by the braking means is changed according to an amount of laundry in the drum. According to this configuration, braking conditions such as the number of revolutions at which braking is started and the braking force are varied according to the amount of laundry.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. For convenience of explanation, the same parts as those in FIGS. 13 and 14 of the conventional example are denoted by the same reference numerals.
FIG. 1 is an external perspective view showing a drum type washing machine according to the first embodiment. Body exterior part 1 that forms the outer wall of the drum type washing machine
Has a front surface that can be opened and closed by an opening / closing door 3. An operation panel 11 provided with operation keys and a display unit is provided on an upper part of the front surface of the main body exterior unit 1.

FIG. 2 is a side sectional view of the drum-type washing machine. As shown in FIG. 2, a bottomed cylindrical water tub 4 having an opening 4a on the front side is provided in the exterior body 1 of the main body. A cylindrical drum 5 with a bottom is disposed in the water tank 4. A motor case 5 is provided in the water tank 4.
The bearing 6 is integrated via 5f.

The shaft 5e fixed to the drum 5 is supported by a bearing 6, so that the drum 5 is rotatable.
A rotor 55e is fixed to the shaft 5e, and the motor case 5
A stator 55d is fixed in 5f. Thus, a motor 55 directly connected to the drum 5 is configured. The motor 55 is formed of a three-phase DC brushless motor, and is driven by a drive voltage supplied by a control unit described later.

A small hole 5a is provided on the entire peripheral wall of the drum 5. The small holes 5a allow the washing water to flow between the water tub 4 and the drum 5 during washing. A baffle 5b is provided on the inner wall surface of the drum 5 so as to protrude therefrom. The laundry is hooked and lifted by the rotation of the drum 5, and the washing is performed by dropping the laundry into the washing liquid.

A fluid balancer 5d is provided on the outer peripheral edge of the opening 5c on the front surface of the drum 5. The fluid balancer 5d is filled with a fluid such as salt water, and the fluid moves when the drum 5 rotates, thereby canceling the shift of the center of gravity due to the offset of the laundry and the washing liquid. Fluid balancer 5
d may be provided on the inner peripheral edge of the drum 5.

The rotation axis y-y of the drum 5 is inclined such that the depth of the drum 5 decreases by an angle θ with respect to the horizontal direction. Thereby, when the user stands and puts the laundry in the front side of the drum type washing machine, the visibility to the depth of the drum 5 is improved.

A packing 1 made of an elastic material such as rubber or soft resin is provided on the periphery of the laundry inlet 1a and the opening 4a of the water tub 4.
0 are attached so as to form a passage for taking in and out the laundry. The packing 10 has such a structure that when the door 3 is closed, the inner peripheral edge 10 a is in close contact with the peripheral edge of the door 3 to close the passage. Thereby, waterproofing during the washing operation is performed. Further, a bellows or the like is provided on the packing 10 so that the packing 10 bends in accordance with the swing of the water tank 4 and follows the tank.

A water supply pipe 12 connected to a water pipe is provided at an upper part in the main body exterior part 1. When a water supply valve 13 provided in the middle of the water supply pipe 12 is opened, a water supply nozzle 15 attached to the door packing 10 via a detergent case 14 is provided.
The water is supplied into the water tank 4 from above.

The drain duct 1 led out from the bottom of the water tank 4
Reference numeral 6 is provided with a connection case 17 having a lint filter 17a provided in the middle of the path and a drainage pump 18, and configured to drain the washing liquid from the water tub 4 to the outside of the main body exterior part 1. The lint filter 17a is formed, for example, by forming a resin into a lattice shape or by forming fine fibers into a bag shape, and accumulates lint and the like in the washing liquid. The lint filter 17a is detachably mounted in the connection case 17, and can be removed from the lower front part of the main body exterior part 1.

A water level sensor 23 is provided above the connection case 17 from an air trap 22 via a pressure guiding pipe 21. The water level sensor 23 is connected to the air trap 2
The magnetic body is moved within the coil according to the pressure change in the coil. The resulting change in inductance of the coil is detected as a change in oscillation frequency, and the water level in the water tank 4 is detected.

FIG. 3 shows a sectional side view of the drum type washing machine different from FIG. 2, and a circulation duct 19 branching from a drain duct 16b is provided at the outlet side of the connection case 17.
The circulation duct 19 is connected to the packing 10 so as to face the opening 4 a of the water tank 4.
It has.

When the drain pump 18 is stopped and the circulation pump 20 is driven, the water tank 4, the drain duct 16a,
A circulation path to the water tank 4 through the connection case 17, the drain duct 16b, the circulation pump 20, and the circulation duct 19 is formed. As a result, the washing liquid in the water tub 4 is circulated through the circulation path, the detergent in the washing liquid is sufficiently dissolved while passing through the circulation path, and the lint filter 17a is used.
To remove lint and the like. Therefore, it is possible to prevent the lint from re-adhering to the laundry.

FIG. 4 shows a further different side cross section. Above the water tub 4, a drying unit 24 for drying laundry, comprising a blower fan 25 and a heater 26, is provided. The drying unit 24 is disposed in the middle of the path of the drying duct 27 that connects the outlet 4b facing the opening 4a of the water tank 4 and the circulation port 4c provided below. A cooler 29 is provided in the middle of the drying duct 27.

The control unit 2 arranged on the back of the operation panel 11
Controls the drum type washing machine, and the configuration is as shown in FIG. The main control unit 41 includes the drum type washing machine 1
Operation unit 43, an input display by the operation unit 43, a display unit 44 for displaying the operation state of the drum-type washing machine 1, a buzzer 45 for notifying an alarm such as the end of the washing operation, and the opening / closing state of the door 3 is detected. It transmits and receives signals to and from a door switch 46 for turning on, a water level sensor 23 for detecting a water level in the water tub 4, a drying sensor 48 for detecting a dry state of the laundry, and a water temperature sensor 49 for detecting the water temperature in the water tub 4.

The sub control unit 42 includes a motor 55, a water supply valve 1
3. The drive of the drain pump 18 and the drying unit 24 is controlled by a drive circuit 60 (see FIG. 7), which will be described later.
e (see FIG. 2). Then, the main control section 41 transmits a transmission signal S1 of control data necessary for rotation of the motor 55 to the sub-control section 42 together with a synchronization clock. After reading the control data, the sub control unit 42 returns a reply signal S2 in synchronization with the clock.

The sub-control unit 42 will be described with reference to the circuit diagram of FIG. The commercial power supply 51 is full-wave rectified by a rectifier circuit 52 composed of a diode bridge and converted into a DC voltage. The DC voltage is smoothed by the smoothing capacitors 53a and 53b and supplied to the inverter circuit 54 as a stable DC power supply. The inverter circuit 54 has six switching elements (transistors 54a to 54f) in a three-phase full-wave bridge configuration.

The transistors 54a, 54 are connected between the positive side of the smoothing capacitor 53a and the negative side of the smoothing capacitor 53b.
4d are arranged in series, and diodes 56a and 56d are arranged in series. Similarly, transistors 54b, 54
e, transistors 54c and 54f, diode 56b,
56e, and diodes 56c and 56f are connected in series, respectively, and convert to three-phase alternating current. Then, from the connection point between the upper arm transistors 54a, 54b, 54c and the lower arm transistors 54d, 54e, 54f, the U phase, V phase of the excitation windings 55a, 55b, 55c of the motor 55, respectively.
Phase, W phase.

A drive circuit 57 is connected to the bases of the transistors 54a to 54f, and the transistors 54a to 54f are driven via the drive circuit 57 by a drive signal from the microcomputer 58. The drive signal is, for example, as shown in FIG.
The PWM signal shown in FIGS.
a and 54d. As a result, the drive voltage shown in FIG. 8C is output to the U phase of the motor 55.

Similar drive voltages are output to the V and W phases of the motor 55 such that the phases are delayed by 120 ° and 240 °, respectively. As a result, a sine-wave current shown in FIG. 8D is generated in the exciting winding 55a. This causes the motor 55 to rotate. 8A to 8D, the vertical axis represents amplitude, and the horizontal axis represents time. A current detecting means 64 for detecting a value of a current flowing through the exciting winding is provided, and is monitored by the microcomputer 58.

The drive signal is generated by a comparator using a triangular wave carrier signal as shown in FIG. The comparator is mounted as a function of the microcomputer 58. In the figure, the vertical axis represents amplitude, and the horizontal axis represents time.
The phase angle θ of the signal of frequency f at time t is θ = 2π
ft. Assuming that the carrier cycle which is the cycle of the carrier signal is Tc and the update amount of the phase angle of the motor 55 for each carrier cycle Tc is Δθ (rotation angle of the rotor 55e), Δθ
= 2πfTc radians.

Therefore, it is necessary for the microcomputer 58 to output a drive signal corresponding to the position advanced by Δθ every carrier cycle Tc. One cycle of drive signal (2π radian)
Is divided into 16 bits (65536), Δθ radian is the phase update amount α = 2πfTc · (65536 / 2π)
= 65536fTc count.

For example, when the period Tc of the carrier signal is 63.
Assuming that the rotation speed of the motor 55 is 60 Hz in 5 μsec, the phase update amount α = 249 counts. The carrier cycle Tc is determined by the timer and the resolution of the pulse width p (see FIG. 8A). Then, a cumulative value N obtained by adding the phase update amount α for each carrier cycle Tc is obtained (that is, N = N
+ Α) to detect the current phase.

A sine wave table is stored in a storage unit (not shown) provided in the control unit 2 in advance. The sine wave table is made up of data of the pulse width p at each phase obtained by dividing 2π radians into 512, and stores 10π / 3 radians (854 data). By referring to the sine wave table, the carrier period T in the phase (512 × N / 65536) corresponding to the accumulated value N is obtained.
The pulse width p for each c is obtained. With respect to the V phase and the W phase, the corresponding pulse widths p can be obtained by referring to the sine wave table from the phase angles delayed by 120 ° and 240 ° with respect to the U phase, respectively.

When the rotation speed f increases due to the accelerated rotation of the motor 55, the phase update amount α needs to be changed accordingly. For this reason, the Hall sensor 59 that detects the rotational position of the rotor 55e has a
タ イ マ A timer is provided at three locations at intervals and detects the number of rotations of the motor 55 during a predetermined period.

From the three Hall sensors 59, the U phase and the V
10 (a), (b), and FIG.
The position signals Hu, Hv, Hw shown in (c) are detected.
The horizontal axis is the phase angle. By detecting the rising and falling edges 83a to 83f of the position signals Hu, Hv, Hw, it is possible to determine six sections D0 to D5 having a phase interval of 60 °.

For example, when the rising edge 83c of the position signal Hw is detected (at a point at a phase angle of 120 °), the position signal H
The timer detects the time from the falling edge 83b of v (the point at a phase angle of 60 °) and resets the timer. Then, the accumulated value N is corrected to the accumulated value N corresponding to the rotational position at that time, and the pulse width corresponding to the phase angle of 0 ° is given to the W phase with reference to the stored data. For the U phase and V phase, the corresponding pulse width can be obtained by referring to the data from the phase angles delayed by 120 ° and 240 ° with respect to the W phase, respectively.

Then, the rotational speed f is obtained from the time from the fall 83b to the rise 83c (section D1), and the phase update amount α is obtained. Next, the phase update amount α is added to the cumulative value N for each carrier cycle Tc, and the rotational position for each carrier cycle Tc is detected from the cumulative value N. Each pulse width corresponding to the rotational position is obtained by a comparator, and a drive signal is output from the microcomputer 58 to rotate the rotor 55e.

In this way, the phase angles are accumulated at intervals of 60 ° even when the fluid balancer 5d is unable to eliminate vibration due to imbalance of the laundry due to acceleration or deceleration, or when the rotation speed is not constant. By correcting the value N, a drive signal corresponding to the rotational position can be obtained accurately.

At the time of startup, the accumulated value N and the phase update amount α are undecided. First, the Hall sensor 59 detects which of the sections D0 to D5. For example, section D
If 1, the cumulative value N is averaged to make the phase angle of the U phase 9
A value corresponding to 0 ° (between 60 ° and 120 °) is obtained, and a drive signal is output by substituting a value experimentally obtained for the phase update amount α. Then, when the rising 83c of the position signal Hw is detected, the cumulative value N is corrected to an accurate value, thereby enabling normal startup.

In the drum-type washing machine having the above-described structure, the operation chart shown in FIG. 5 is executed by the control unit 2 to perform a washing operation. The washing operation will be described below with reference to FIG. When the laundry is thrown in from the laundry inlet 1a and the door 3 is closed, the inner peripheral edge 10a of the packing 10 is brought into close contact with the peripheral edge of the door 3, and the water tub 4 is sealed. And
When the detergent is put in the detergent case 14 and the operation panel 11 (the operation unit 43) is operated, a washing operation including a “washing process”, a “rinsing process”, a “dehydration process”, and a “drying process” is performed according to a command from the control unit 2. Be started.

First, in the water supply operation of the "washing step", the opening / closing door 3 is locked and the water supply valve 13 is opened. Based on the opening of the water supply valve 13, the tap water is supplied on the way to the detergent case 1.
4 flows into the water tank 4 and the drum 5 together with the detergent from the water supply nozzle 15. When the water level in the water tank 4 reaches a predetermined water level, the water level sensor 23 detects the water level and the water supply valve 1 is detected.
3 is closed, the drive mechanism 9 is driven to control the rotation of the drum 5 according to a predetermined cleaning chart, and the cleaning operation is performed for a predetermined time.

The rotation of the drum 5 is set in a washing, rinsing, spin-drying and drying process, or a rotation chart according to the type of laundry, a rotation speed, and a reversal time and a reversal cycle. Or automatically selected.

When the "washing step" is completed, the process proceeds to a "rinsing step" in which the rinsing dehydration operation and the stirring rinsing operation are alternately repeated a plurality of times. In the “rinsing step”, first, the drainage pump 18 is operated to supply the washing liquid to the drainage duct 1.
6. A draining operation of draining water to the outside of the main body exterior part 1 via the connection case 17 is performed.

When the drain operation is completed, the drum 5 rotates in the first dehydration chart, and the rinse dehydration operation is performed.
The washing liquid of the laundry is discharged to the inner wall of the water tub 4 through the small holes 5a provided in the peripheral wall of the drum 5 by the centrifugal force generated by the spinning rotation. The washing liquid flowing down to the lower part of the water tub 4 along the inner wall is drained to the outside through drain ducts 16a and 16b.

During this rinsing and dewatering operation, the water supply valve 13 may be opened and tap water may be injected from the water supply nozzle 15 into the water tank 4. By doing so, the tap water can permeate the laundry by centrifugal force, and the detergent remaining on the laundry can be efficiently removed. The first dehydration chart is a chart suitable for dehydrating a washing liquid containing a large amount of detergent by suspending the rotation of the drum or changing the rotation speed.

When the rinse dehydration operation is completed, a water supply operation is performed, the drain pump 18 is stopped, and the water supply valve 13 is opened again. When the water level in the water tank 4 reaches a predetermined level with the opening of the water supply valve 13, the water supply valve 13 is closed, and the driving mechanism 9 drives the drum 5 to rotate according to the rinse chart, thereby performing the stirring rinse operation.

During the stirring and rinsing operation, a soft finish agent storage box (not shown) and a rinse water supply path communicating with the soft finish agent storage box may be separately provided, and water may be supplied from the rinse water supply route together with the soft finish agent. Further, the circulation pump 20 may be driven during the washing operation or the stirring and rinsing operation to circulate the washing liquid in the water tub 4.

When the “rinsing step” is completed by repeating the above-described rinsing and dehydrating operation and the stirring rinsing operation several times, the program is switched to the “dehydrating step”. In the “dehydration step”, first, a drain operation of closing the water supply valve 13 and operating the drain pump 18 to drain the washing liquid to the outside is performed.

Then, the drum 5 is rotated in the second dehydration chart to perform the finish dehydration operation. In the finish dewatering operation, the washing liquid is discharged to the inner wall of the water tub 4 through the small holes 5a formed in the peripheral wall of the drum 5 by the centrifugal force generated by the dewatering rotation.
Thereafter, the washing liquid flows down the inner wall of the water tub 4 to the lower part, and is drained to the outside from the drain duct 16.

When the “dehydration step” is completed, a “drying step” for drying the laundry is performed. Before the “drying step”, a short period of time is required to remove the laundry stuck to the inner wall of the drum 5. A “peeling step” (not shown in FIG. 5) is performed. In the "peeling step", first, the drum 5 is rotated at a predetermined rotation speed for a short time. This time is, for example, 400 mse
c Alternatively, the rotation angle of the drum 5 may be about 6 °.

Then, the power supply to the motor 55 is cut off by the drive circuit 57, and after an inertial rotation period of about 0.1 sec has elapsed, the motor 55 is suddenly braked electrically.
When the motor 55 is driven, the upper arm transistor 5
4a to 54c and transistors 54d to 5d for the lower arm
Since 4f is sequentially switched, the switching noise is transmitted from the motor 55 to the Hall sensor 59. By providing an inertial rotation period from the driving rotation state of the motor 55 to the sudden braking, this noise can be removed. Then, after the position is accurately detected by the Hall sensor 59, the state is shifted to the braking state, so that abnormal noise due to control can be suppressed.

The sudden braking of the motor 55 is performed by the following method. When the power supply to the motor 55 is cut off, the drum 5 rotates by inertia, and electromotive forces Wu, Wv, and Ww are generated between the exciting windings 55a, 55b, and 55c as shown in FIG. At this time, the transistors 54d to 54f for the lower arm are used.
When (see FIG. 7) is turned on, the motor 55 is subjected to short-circuit braking.

That is, each excitation winding 55a, 55b, 55c
Are short-circuited, and power is consumed by the resistance of the exciting windings 55a, 55b, 55c. As a result, the kinetic energy of the motor 55 is consumed, so that the motor 55 is braked and decelerated. When the transistors 54d to 54f are turned off, the motor 55 is not braked.
By varying the time ratio (hereinafter, referred to as "braking rate") for turning ON the? 54f, the braking ability (hereinafter, referred to as "braking force") can be varied.

The electric braking of the motor 55 may be performed by regenerative braking. That is, the excitation windings 55a, 55b, 55
The inverter control circuit 54 supplies the motor 55 with a sine wave voltage delayed by approximately 180 ° from the electromotive forces Wu, Wv, and Ww by the electromotive forces Wu, Wv, and Ww generated between c.
Thus, the voltage generated by the motor 55 is regenerated to the power supply, and the motor 55 can be braked.

Further, braking may be performed electrically by DC braking, power generation braking, or the like. In the case of DC braking, the motor 55 is braked by the power from the power source, for example, by turning on the U-phase upper-arm transistor 54a and turning on the V-phase and W-phase lower-arm transistors 54e and 54f. be able to.

When the amount of laundry in the drum 5 is large, that is, 60% or more of the rated capacity, a large torque is required for braking. Therefore, as shown in FIG. Increase power. Further, since the inertia force is large, a force for peeling can be applied to the laundry even when sudden braking is performed when the rotation speed of the motor 55 is a low rotation speed of, for example, 100 rpm. Therefore, the driving time of the motor 55 can be shortened, and braking can be performed in a short time.

When the amount of the laundry is 30 to 50% of the rated capacity, a medium capacity or a small capacity of 30% or less, a large torque is not required for braking, and as shown in FIG. Accordingly, the braking rates are set to 50% and 20%, respectively. Vibration during sudden braking can be suppressed by lowering the braking rate. And
The number of rotations of the motor 55 is, for example, 150 rpm, 2
By performing rapid braking at a high rotational speed of 00 rpm, a force for peeling can be applied to the laundry.

The amount of laundry in the drum 5 is determined by the motor 5
5 can be detected from the transition of the number of revolutions at the rise. When the motor 55 is started, the duty ratio and the pulse width of the drive voltage (see FIG. 8C) are varied according to the rotational position, and the motor 55 is driven to the first rotational speed. After the rotation speed of the motor 55 reaches the first rotation speed, the duty ratio of the drive voltage is fixed, and the pulse width p (modulation rate) is varied to increase the rotation speed to a predetermined second rotation speed.

At this time, since the duty ratio of the drive voltage is fixed, the output of the motor 55 becomes constant. Therefore, when the modulation rate is changed to increase the rotation speed, the drum 5
When the moment of inertia of the drum 5 is large, it accelerates slowly, and when the moment of inertia of the drum 5 is small, it accelerates sharply.
Therefore, it is possible to detect the amount of the laundry by the time until the drum 5 reaches the predetermined first rotation speed to the second rotation speed.

By the above-mentioned "peeling step", the laundry adhered to the inner wall of the drum 5 is peeled. Since the motor 55 is directly connected to the drum 5, the drum 5 follows the rotation and braking of the motor 55, and the laundry can be separated in a short time. In addition, the rotation and sudden braking of the drum 5 are as follows.
It may be performed a plurality of times, such as forward rotation, sudden braking, reverse rotation, and sudden braking.

At the time of the inertial rotation of the drum 5 immediately before the end of the “dehydrating step”, the rotation speed of the drum 5 is set to 200, for example.
Rapid braking may be performed when the speed is reduced to not more than rpm, and then the “peeling step” may be performed. This makes it possible to improve the effect of removing the laundry without increasing the washing time.

At this time, as described above, the braking time and the braking start timing are varied according to the capacity of the laundry, so that the braking time is reduced when the capacity is large, and the vibration during braking is reduced when the capacity is small. Can be suppressed.

When the “peeling step” is completed, the “drying step” is executed by rotating the drum 5 according to the drying chart and driving the blower fan 25 and the heater 26. In the “drying process”, the air that has absorbed the moisture of the laundry in the drum 5 is driven by the driving of the blowing fan 25 so that the small holes 5 a of the drum 5
Circulating port 4c of water tank 4, drying duct 27, blower fan 2
5, circulates through the heater 26 into the drum 5 from the outlet 4b.

The air containing moisture is cooled by a cooler 29 provided in the drying duct 27 while passing through the drying duct 27, so that the temperature is lowered. As a result, the drying duct 2
The air inside 7 is dehumidified by the dew condensation of water, and becomes low humidity air to reach the heater 26.

The air heated by the heater 26 becomes warm air and is blown into the water tub 4 from the outlet 4b, and comes into contact with the laundry again to absorb moisture. The air is again sucked into the drying duct 27 from the circulation port 4a, and is similarly cooled and dehumidified by the cooler 29. By repeating this operation, the laundry is dried.

Then, the degree of drying in the drum 5 is detected by the drying sensor 48, and when a predetermined value is obtained, the "drying step" ends. The water condensed by the dehumidification in this “drying step” descends in the drying duct 27 and is drained to the outside from the circulation port 4 c through the drain duct 16.

As described above, the steps of washing, rinsing, dehydrating, and drying are continuously performed, and the laundry is washed and dried. Further, each of the steps of washing, rinsing, spin-drying and drying can be independently executed by setting from the operation panel 11.

As described above, according to the present embodiment, by directly connecting the motor 55 composed of a DC brushless motor to the drum 5 and directly driving the drum 5, the extension of the belt, the pulley, Friction between the motor and the belt can be eliminated.

As a result, the drum 55 accurately follows the rotation and braking of the motor 55, and it becomes possible to apply a force to the laundry adhered to the inner wall of the drum 5 by short-time rotation and rapid braking. Therefore, the laundry can be peeled in a short time even with a small number of rotations, so that the time of the "peeling step" can be shortened, and damage and noise of the motor 55 can be prevented. Further, by performing the electrical braking by short-circuit braking or regenerative braking, power is not supplied to the motor 55 during braking, so that power consumption can be reduced.

[0085]

According to the present invention, by directly connecting the motor to the drum and directly driving the drum, the elongation of the belt and the friction between the pulley and the motor and the belt can be eliminated as in the prior art. This makes it possible for the drum to accurately follow the rotation and braking of the motor, and to apply a force to the laundry attached to the inner wall of the drum by short-time rotation and rapid braking. Therefore, even at a small number of rotations, the laundry can be dried in a short time without peeling off wrinkles. Then, the time of the “peeling step” is shortened, and the time of the washing time can be shortened. In addition, damage to the motor and noise can be prevented.

Also, according to the present invention, the DC brushless motor can be easily electrically braked because of the provision of the inverter circuit, and the short-circuit braking or the regenerative braking is performed by the electromotive force generated by the motor that rotates by inertia when the driving power is cut off. By performing braking, power is not supplied to the motor during braking, and power consumption can be reduced.

Further, according to the present invention, before the motor is braked, by providing a period in which the drive power of the motor is cut off and the inertial rotation is performed, the switching noise transmitted from the motor to the position detecting unit can be removed. Then, by shifting to the braking state after accurately detecting the position, abnormal noise due to control can be suppressed.

Further, according to the present invention, by effecting rapid braking during the inertial rotation of the drum immediately before the end of the spin-drying step and then executing the peeling step, the effect of peeling the laundry without increasing the washing time is improved. It is possible to do.

Further, according to the present invention, the braking capacity such as the braking rate and the braking start timing is varied according to the capacity of the laundry in the drum before the dehydrating step or during the braking step, so that the capacity is large. In this case, the braking time can be reduced, and when the capacity is small, vibration during braking can be suppressed without extending the braking time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a drum type washing machine according to an embodiment of the present invention.

FIG. 2 is a side sectional view showing the drum type washing machine according to the embodiment of the present invention.

FIG. 3 is a side sectional view of another cut surface of the drum type washing machine according to the embodiment of the present invention.

FIG. 4 is a side sectional view of still another cut surface of the drum type washing machine according to the embodiment of the present invention.

FIG. 5 is a chart showing a washing operation of the drum type washing machine according to the embodiment of the present invention.

FIG. 6 is a configuration diagram illustrating a control unit of the drum-type washing machine according to the embodiment of the present invention.

FIG. 7 is a circuit diagram showing a sub control unit of the drum type washing machine according to the embodiment of the present invention.

FIG. 8 is a diagram illustrating a signal waveform in driving a motor of the drum type washing machine according to the embodiment of the present invention.

FIG. 9 is a diagram illustrating a signal waveform of a comparator of the drum type washing machine according to the embodiment of the present invention.

FIG. 10 is a diagram showing a position signal by a hall sensor of the drum type washing machine according to the embodiment of the present invention.

FIG. 11 is a diagram showing an electromotive force of a DC brushless motor of the drum type washing machine according to the embodiment of the present invention.

FIG. 12 is a diagram illustrating an electric braking method of the drum type washing machine according to the embodiment of the present invention.

FIG. 13 is a side sectional view of a conventional drum-type washing machine.

FIG. 14 is a front view of a conventional drum type washing machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body exterior part 2 Control part 3 Opening / closing door 4 Water tank 5 Drum 9 Drive mechanism 10 Packing 12 Water supply pipe 13 Water supply valve 16 Drain duct 17 Connection case 18 Drain pump 20 Circulation pump 23 Water level sensor 24 Drying unit 25 Draft fan 26 Heater 27 Drying Duct 28 Weight 41 Main control unit 42 Sub-control unit 52 Rectifier circuit 54 Inverter circuit 55 Motor 59 Hall sensor

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // H02K 29/00 H02K 29/00 Z F term (Reference) 3B155 BA03 BA18 BB15 BB16 CA02 CB07 CB43 DC02 DC15 FA02 FA06 FA14 GB10 HB02 HB10 HB24 KA19 KA36 KB11 LA03 LA14 LB02 LB04 LC07 LC15 LC28 MA02 MA07 MA08 MA09 5H019 AA04 AA06 AA07 BB05 CC03 FF01 5H607 AA04 AA12 BB01 BB09 BB14 CC01 CC09 DD03 FF00H01 BB00

Claims (7)

[Claims] 1. A bottomed cylindrical drum rotatably supported and into which laundry is put, a motor directly connected to the drum and driving the drum to rotate, and a brake for electrically braking the motor. A washing machine, a rinsing step, a spin-drying step, and a drying step, which are sequentially performed by rotating the drum. A drum type washing machine wherein a peeling step of peeling laundry from an inner wall of the drum by braking by a braking means is performed after the dewatering step and before the drying step. 2. The motor according to claim 1, wherein the motor comprises a DC brushless motor having an exciting winding, and an inverter circuit for converting a rectified power supply voltage into a drive voltage for the DC brushless motor. Drum type washing machine. 3. The motor according to claim 1, wherein a period during which the driving power of the motor is cut off and the motor rotates by inertia is provided before the motor is braked by the braking means. Drum type washing machine. 4. The drum type washing machine according to claim 2, wherein the braking means short-circuits the exciting winding in a state where the driving power of the motor is cut off. 5. The braking device according to claim 2, wherein the braking means performs regenerative braking on an electromotive force generated from the motor that rotates by inertia while the driving power of the motor is cut off.
Or the drum type washing machine according to claim 3. 6. The motor is braked by the braking means when the rotation speed of the drum which rotates by inertia becomes lower than a predetermined rotation speed before the completion of the dehydrating step. The drum type washing machine according to any one of claims 1 to 5. 7. The drum-type washing machine according to claim 1, wherein a braking condition of the drum by the braking unit is changed according to an amount of the laundry in the drum. .