JP2008099799A - Driving device for laundry - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To use a DC brushless motor having excellent motor efficiency and an appropriate size and facilitating motor specification selection and design. <P>SOLUTION: The driving unit 13 for laundry includes a first motor 7 composed of the DC brushless motor for rotationally driving a drum 5 inside a water tub 3 directly and a second motor 9 composed of the DC brushless motor for rotationally driving the drum 5 through a reduction mechanism 12, drives the first motor 7 when rotating the drum 5 at a high speed and drives the second motor 9 when rotating the drum 5 at a low speed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laundry driving device that rotationally drives a drum of a drum type laundry machine such as a drum type washing machine.

Some drum-type washing machines have a configuration in which the drum is directly rotated by a DC brushless motor (for example, Patent Document 1). In this device, the drum is rotated at a low speed by a DC brushless motor at the time of washing, and is rotated at a high speed at the time of dehydration.
Japanese Patent Laid-Open No. 11-28298

  However, in the above-described conventional one, it is necessary to cover both the low-speed rotation region for washing and the high-speed rotation region for dehydration by the DC brushless motor (see FIG. 7). However, in this case, as can be seen from FIG. 7, the characteristics of the DC brushless motor must be determined such that the high efficiency point is in the intermediate speed rotation range between the low speed rotation range and the dehydration high speed rotation range, and To obtain the necessary motor torque in both the low-speed rotation range and the high-speed rotation range of dehydration, the motor must be able to exhibit a considerably large motor torque, and is a large, powerful, high-precision DC brushless motor. Is required. In this case, since the high torque region in the intermediate speed rotation region cannot be used for load driving, there is a problem that the motor efficiency is poor.

  The present invention has been made in view of the above-described circumstances, and its purpose is to have a high motor efficiency and to use a DC brushless motor of an appropriate size, and to facilitate motor specification selection and design. The object is to provide a laundry drive.

  The first aspect of the invention includes a first motor composed of a DC brushless motor that directly rotates the drum inside the tank, and a second motor composed of a DC brushless motor that rotationally drives the drum via a reduction mechanism. And the first motor is driven when the drum is rotated at a high speed, and the second motor is driven when the drum is rotated at a low speed.

  According to the first aspect of the present invention, the first motor is driven when the drum is rotated at a high speed, and the second motor is driven when the drum is rotated at a low speed. It is only necessary to use a high-efficiency motor for a part of the motor, and it is easy to select and design the motor. For the second motor, it is only necessary to apply a low-speed rotation after decelerating by the speed reduction mechanism, so use a high-speed and low-torque motor. This makes it easy to select and design the motor, and to drive the drum with high torque by the speed reduction mechanism.

  Hereinafter, an embodiment in which the present invention is applied to a drum type washing machine will be described with reference to FIGS. 1 and 2 show a schematic configuration of the drum type washing machine 1. 1 and 2, a water tank 3 as a tank is disposed in the outer box 2 of the drum type washing machine 1 via a plurality of elastic support mechanisms 4, and the drum 5 rotates in the water tank 3. It is accommodated and arranged. A large number of holes are formed in the peripheral wall of the drum 5.

  The water tank 3 and the drum 5 are in a substantially horizontal state with a rearward drop, and a shaft 5 a extending rearward from the rear end of the drum 5 is rotatably supported by a bearing 6. A rotor 7a of the first motor 7 provided on the rear surface of the water tank 3 is attached to the shaft 5a so as to rotate integrally. The first motor 7 is composed of a DC brushless motor and is an outer rotor type. The rotor 7a includes a rotor magnet. A pulley 8 is attached to the outer periphery of the rotor 7 a of the first motor 7. The first motor 7 is used in a dehydration rotation region that is a high-speed rotation region, that is, used as a dehydration motor.

  A second motor 9 is disposed at the lower part of the outer box 2. The second motor 9 is also a DC brushless motor. A pulley 10 is attached to the rotation shaft of the second motor 9 so as to rotate integrally. For example, a V-type belt 11 is stretched between the pulley 10 and the pulley 8. The pulleys 8 and 10 and the belt 11 constitute a belt-type speed reduction mechanism 12. In this case, the diameter of the pulley 10 is smaller than the diameter of the pulley 8. The second motor 9 is used in a washing rotation range which is a low-speed rotation range, that is, used as a washing motor. The first motor 7, the second motor 9, and the speed reduction mechanism 12 constitute a main part of the laundry driving device 13.

  FIG. 3 shows an electrical configuration of the laundry driving device 13. For example, a power supply circuit 14 including a voltage doubler rectifier circuit is connected to the plug 13P connected to the outlet of the commercial AC power supply. A drive circuit 15 for a dehydrating motor and a drive circuit 16 for a washing motor are connected to the power supply circuit 14. These drive circuits 15 and 16 are constituted by inverter circuits, and the output terminal of the drive circuit 15 for the dehydrating motor is connected to the three-phase of the first motor 7 via the first motor switch 17. The output terminal of the washing motor drive circuit 16 is connected to the three-phase stator coil of the second motor 9 via the second motor switch 18.

  Here, the first motor 7 is selected in advance so as to have the highest efficiency in a high-speed rotation range (for example, about 1000 rpm) as shown in FIG. Further, the second motor 9 is selected in advance so as to have the highest efficiency in the high-speed rotation region N in consideration of deceleration by the speed reduction mechanism 12. In this case, the drum 5 is rotated at a low speed (for example, about 50 rpm) by the deceleration by the speed reduction mechanism 12.

  Further, the stator coil of the first motor 7 is connected to the power storage device 20 via the first switch 19, and the stator coil of the second motor 9 is connected to the power storage device 19 via the second switch 21. It is connected. The power storage device 19 includes means for converting the three-phase alternating current power input from the motors 7 and 9 into direct current, and a power storage device that stores the direct current power. The power supply circuit 14 can be regenerated to the DC output side.

Further, a control power supply circuit 22 is connected to the power supply circuit 14, and the control power supply circuit 22 generates a control power supply such as a control circuit 23.
The control circuit 23 is for driving and controlling the first motor 7 and the second motor 9 via the drive circuits 15 and 16, and includes a microcomputer.

  In the drum type washing machine 1, washing operation such as detergent washing operation and rinsing washing operation and dehydration operation are performed, and the control circuit 23 makes the drum 5 normal at a low speed (for example, 50 rpm) during the washing operation. It is rotated by rotation, pause, reverse rotation, and pause (see FIG. 5). In this case, as shown in FIG. 6, only the second motor switch 18 is closed (the switches 17, 19, and 21 are opened), and the second motor 9 is driven and controlled in the forward and reverse directions. At this time, the first motor 7 idles.

  Further, when the power storage device 20 is charged during the washing operation, the first switch 19 is further closed. Then, the first motor 7 functions as a generator and stores power in the power storage device 20. In this case, the first motor 7 also acts as a brake for the second motor 9.

  Further, when braking forward and reverse rotation of the drum 5 during the washing operation, the operation of the inverter circuit in the drive circuit 16 is stopped, the second motor switch 18 is opened, and the first switch 19 is opened. , 21 is closed and both motors 7 and 9 are caused to generate electric power to obtain a brake function.

  Further, during the dehydration operation, the drum 5 is rotated in a high speed rotation range (for example, about 1000 rpm) as shown in FIG. In this case, as shown in FIG. 6, only the first motor switch 17 is closed. Then, the first motor 7 is rotated and the drum 5 is directly rotated at a high speed. At this time, the second motor 9 idles.

  Further, the second switch 21 is further closed when the power storage device 20 is turned off during the dehydration operation. Then, the second motor 9 functions as a generator and stores power in the power storage device 20. In this case, since the speed reduction mechanism 12 acts as a speed increasing mechanism for the second motor 9, the rotation speed of the second motor 9 is high, the power generation efficiency is high, and the power storage device 20 stores power in the power storage device. The effect goes up. Also in this case, the second motor 9 acts as a brake.

  When braking the high-speed rotation of the drum 5 during the dehydrating operation, the first motor switch 17 is opened, the first switches 19 and 21 are closed, and both the motors 7 and 9 are caused to generate power. And get the brake function.

  According to the present embodiment, the first motor 7 is driven when the drum 5 is rotated at a high speed, and the second motor 9 is driven when the drum 5 is rotated at a low speed. As long as a high-efficiency motor is used in a part such as a high-speed rotation range, it is easy to select and design the motor, and the second motor 9 only needs to be decelerated by the speed reduction mechanism 12 and can be provided with a low-speed rotation. A high-speed, low-torque motor can be used, and the motor can be easily selected and designed, and the drum 5 can be driven with high torque by the speed reduction mechanism 12.

  Moreover, according to the present Example, it has the electrical storage apparatus 20, and this electrical storage apparatus 20 is connected to the 1st motor 7 and the 2nd motor 9 via the 1st switch 19 and the 2nd switch 21, respectively. Therefore, by appropriately opening and closing these switches 19 and 21, power can be stored, and the stored energy can be regenerated and used on the power source side, and the first motor 7 can be used. And it can also be made to act as a brake means with respect to the 2nd motor 9 suitably.

  In this case, according to the present embodiment, when one of the first motor 7 and the second motor 9 is driven, the other motor stores power in the power storage device 20, and therefore the other motor The rotation of the motor can be used effectively for power storage.

  Furthermore, according to this embodiment, when braking the rotation of the drum 5, the electric brake (a kind of regenerative brake that generates and stores electricity) by both the first motor 7 and the second motor 9 is operated. Therefore, rapid braking action can be obtained, and power storage can be promoted. In this case, the electric brake may be operated by either one of the motors 7 and 9.

  Further, according to the present embodiment, the first motor 7 is an outer rotor type, and the speed reduction mechanism 12 is rotated by the pulley 8 provided on the outer periphery of the rotor 7 a of the first motor 7 and the rotation of the second motor 9. Since the belt 11 is stretched between the pulley 10 as a part, the speed reduction mechanism 12 can be configured using the rotor 7a of the first motor 7 in a form directly connected to the drum 5. Simple structure and good transmission efficiency (low transmission loss).

In addition, since the drive circuits 15 and 16 are composed of inverter circuits, the operation frequency can be easily changed, the range of the rotational speed at which operation can be performed is widened, and further improvement in efficiency can be expected.
In the above embodiment, the present invention is applied to a drum type washing machine, but may be applied to a drum type washing machine or a drum type drying machine. The speed reduction mechanism is not limited to a belt type speed reduction mechanism, and may be a sprocket, a chain type speed reduction mechanism, or the like.

The partially broken side view of one Example which applied this invention to the drum type washing machine Partially broken rear view of drum-type washing machine Electrical configuration block diagram The figure which shows the rotational characteristic of a 1st motor and a 2nd motor Diagram showing drum rotation pattern in washing operation and dehydration operation The figure which shows the switching pattern of the switch for action explanation Motor rotation characteristic diagram for explaining a conventional example

Explanation of symbols

  In the drawings, 1 is a drum type washing machine, 3 is a water tub (tank), 5 is a drum, 7 is a first motor, 9 is a second motor, 12 is a speed reduction mechanism, 13 is a laundry drive, and 17 is a first drive. 1 is a motor switch, 18 is a second motor switch, 19 is a first switch, 20 is a power storage device, 21 is a second switch, and 23 is a control circuit.

Claims (5)

A first motor comprising a DC brushless motor that directly rotates and drives the drum inside the tank;
A second motor composed of a DC brushless motor that rotationally drives the drum via a reduction mechanism;
A laundry driving apparatus characterized in that the first motor is driven when the drum is rotated at a high speed, and the second motor is driven when the drum is rotated at a low speed. A power storage device,
2. The laundry driving device according to claim 1, wherein the power storage device is connected to the first motor and the second motor via a first switch and a second switch, respectively.   3. The laundry drive device according to claim 2, wherein when one of the first motor and the second motor is driven, the other motor stores power in the power storage device.   2. The laundry driving apparatus according to claim 1, wherein when braking is applied to the rotation of the drum, an electric brake by one of the first motor and the second motor is operated. The first motor is an outer rotor type,
2. The laundry driving device according to claim 1, wherein the speed reduction mechanism has a configuration in which a belt is stretched between a rotor outer peripheral portion of the first motor and a rotating portion of the second motor. .

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