JP6509503B2 - Drum type washing machine - Google Patents

Description

  The present invention relates to a drum-type washing machine. The drum type washing machine may be one which is continuously performed from washing to drying, or may be one which carries out washing but not drying.

  Conventionally, in a drum-type washing machine, a horizontal axis type drum is rotated in an outer tank with water stored at the bottom, and the laundry is lifted and dropped by a baffle provided in the drum, and the laundry is on the inner periphery of the drum The laundry is washed by tapping on the surface (see Patent Document 1).

  As described above, in the configuration in which the laundry is stirred by the baffle, the laundry is less likely to intertwine or rub against each other. For this reason, as compared with a full-automatic washing machine in which the pulsator rotates the pulsator in the washing and dewatering tank to wash the laundry, the drum-type washing machine tends to have a smaller mechanical force acting on the laundry and tends to have a lower cleaning performance.

  Therefore, in the drum-type washing machine, in order to improve the washing performance, a configuration may be adopted in which an agitating body is provided on the rear surface of the drum and the drum and the agitating body are rotated at different rotational speeds during washing and rinsing. In this case, a configuration may be further adopted in which the rotation of the drive motor is decelerated by a gear reduction mechanism and transmitted to the drum.

JP, 2013-240577, A

  However, in the drum-type washing machine, in the case where the rotation of the drive motor as described above is decelerated by the speed reduction mechanism using gears and transmitted to the drum, the energization of the drive motor is stopped. , Loud noise is likely to occur from the speed reduction mechanism. As a result of the drive motor trying to stop but the drum continues to rotate by inertia force, a large impact is applied to the gears of the reduction mechanism, which is considered to be a factor of noise generation.

  The present invention has been made in view of such problems, and in stopping a drum in a drum type washing machine having a configuration in which rotation of a drive motor is decelerated by a speed reduction mechanism using gears and transmitted to the drum. An object of the present invention is to reduce abnormal noise generated from a speed reduction mechanism.

  A drum-type washing machine according to a main aspect of the present invention comprises an outer tub disposed in a housing, and a drum disposed in the outer tub and rotatable around a horizontal axis or an inclined axis inclined with respect to the horizontal direction. A drive unit including a drive motor and a reduction mechanism for decelerating the rotation of the drive motor using a gear and transmitting it to the drum; a motor drive unit for supplying a drive current to the drive motor; and controlling the motor drive unit And a control unit. Here, when the control unit stops the rotation of the drum decelerated by the reduction mechanism, the control unit controls the motor drive unit such that the drive current supplied to the drive motor is gradually reduced.

  According to the above configuration, when the rotation of the drum decelerated by the reduction mechanism is stopped, the drive motor is stopped after the rotational speed gradually decreases. Thus, the impact applied to the gear of the speed reduction mechanism when the drive motor is stopped can be reduced, so that the generation of abnormal noise of the speed reduction mechanism can be reduced.

  In the drum-type washing machine according to the present aspect, the motor drive unit may be configured to adjust a drive current in accordance with the rotation speed of the drive motor set by the control unit. In this case, when the control unit stops the rotation of the drum decelerated by the reduction mechanism, the control unit sets the rotational speed of the drive motor so as to decrease by a predetermined speed every predetermined time.

  According to the above configuration, the rotational speed of the drive motor can be reduced by applying the same time regardless of the magnitude of the load amount, regardless of the load amount or the like, and generation of abnormal noise of the speed reduction mechanism It can be reduced well.

  In the drum-type washing machine according to the present aspect, a configuration may be further provided, which further includes a rotating body disposed at the rear of the drum and having a projecting portion on the surface that comes in contact with the laundry. In this case, the drive unit decelerates the rotation of the drive motor by the reduction mechanism and transmits the drive mode of the drive unit to the drum at different rotational speeds. A two-axis drive mode of rotating, and a single-axis drive mode of integrally rotating the drum and the rotating body at the same rotational speed by transmitting rotation of the drive motor to the drum without decelerating the rotation of the drive motor. And a clutch mechanism that switches between the two. The control unit controls the motor drive unit such that a drive current supplied to the drive motor is gradually decreased when the rotation of the drum is stopped in the two-axis drive mode. The motor drive unit is controlled to immediately stop the supply of a drive current to the drive motor when stopping the rotation of the drum.

  According to the above configuration, for example, when the drive form of the drive unit is switched to the biaxial drive form at the time of washing and rinsing, not only the mechanical force by the rotation of the drum but also the mechanical force by the rotating body can be applied to the laundry The improvement of the cleaning performance can be expected. Also, for example, when the drive mode is switched to the uniaxial drive mode at the time of dewatering, the laundry stuck to the drum can be prevented from being stirred by the rotating body, and the laundry can be dewatered favorably.

  Furthermore, according to the above configuration, the motor drive unit controls the drive current supplied to the drive motor to be gradually reduced when stopping the rotation of the drum in the two-axis drive configuration in which the noise from the reduction mechanism is concerned Therefore, the generation of abnormal noise of the speed reduction mechanism can be reduced. On the other hand, when the rotation of the drum is stopped in the single-axis drive mode in which no noise from the speed reduction mechanism is concerned, the motor drive unit is controlled to immediately stop the supply of the drive current to the drive motor. It is possible to prevent prolonging the time required for stopping.

  According to the present invention, when the drum-type washing machine adopts a configuration in which the rotation of the drive motor is decelerated by the gear reduction mechanism and transmitted to the drum, the noise is generated from the reduction gear when stopping the drum. Can be reduced.

  The effects and significances of the present invention will become more apparent from the following description of the embodiments. However, the following embodiment is merely an example in practicing the present invention, and the present invention is not limited to the one described in the following embodiment.

It is a side sectional view showing the composition of a drum type washing machine concerning an embodiment. It is sectional drawing which shows the structure of the drive unit based on embodiment. It is sectional drawing which shows the structure of the drive unit based on embodiment. It is a front view of a rotor showing composition of a rotor of a drive motor concerning an embodiment. It is an enlarged perspective view of the rear of a bearing unit in which a spline was formed concerning an embodiment. It is a figure which shows the structure of the clutch body of a clutch mechanism part based on embodiment. It is a block diagram showing composition of a drum type washing machine concerning an embodiment. It is a flowchart which shows stop control processing based on embodiment. FIG. 7 is a diagram schematically showing the movement of the set speed and the movement of the actual rotational speed of the drive motor when the stop control process is performed according to the embodiment. FIG. 8 is a view schematically showing the movement of the actual rotational speed of the drive motor when the stop control process is performed in the case where the load amount is large and the case where the load amount is small according to the embodiment.

  Hereinafter, the drum type washing machine which does not have a drying function which is one embodiment of the drum type washing machine of the present invention will be described with reference to the drawings.

  FIG. 1 is a side cross-sectional view showing the configuration of the drum-type washing machine 1.

  Drum type washing machine 1 is provided with case 10 which constitutes an appearance. The front surface 10 a of the housing 10 is inclined from the central portion to the upper portion, and a laundry loading port 11 is formed on the inclined surface. The inlet 11 is covered by an openable door 12.

  In the housing 10, the outer tub 20 is elastically supported by a plurality of dampers 21. A drum 22 is rotatably disposed in the outer tank 20. The outer tank 20 and the drum 22 are inclined so that the rear side is lower than the horizontal direction. Thus, the drum 22 rotates about an inclined axis inclined with respect to the horizontal direction. The inclination angle of the outer tub 20 and the drum 22 may be about 10 to 20 degrees. The opening 20a on the front surface of the outer tank 20 and the opening 22a on the front surface of the drum 22 face the insertion port 11, and both the insertion port 11 are closed by the door 12. A large number of dewatering holes 22 b are formed on the inner peripheral surface of the drum 22. Furthermore, three baffles 23 are provided on the inner circumferential surface of the drum 22 at substantially equal intervals in the circumferential direction.

  At the rear of the drum 22, a stirrer 24 is rotatably disposed. The stirrer 24 has a substantially disc shape. On the surface of the agitating body 24, a plurality of blades 24a extending radially from the central portion are formed. The stirrer 24 rotates coaxially with the drum 22. The stirring body 24 corresponds to the rotating body of the present invention, and the blade 24 a corresponds to the projecting portion of the present invention.

  Behind the outer tank 20, a drive unit 30 for generating a torque for driving the drum 22 and the agitator 24 is disposed. The drive unit 30 corresponds to the drive unit of the present invention. The drive unit 30 rotates the drum 22 and the stirrer 24 in the same direction at different rotational speeds during the washing and rinsing steps. Specifically, the drive unit 30 rotates the drum 22 at a rotational speed at which the centrifugal force applied to the laundry in the drum 22 is smaller than gravity, and the agitator 24 has a rotational speed faster than the rotational speed of the drum 22 Rotate at. On the other hand, in the dewatering process, the drive unit 30 integrally rotates the drum 22 and the stirring body 24 at a rotational speed at which the centrifugal force applied to the laundry in the drum 22 becomes much larger than the gravity. The detailed configuration of the drive unit 30 will be described later.

  At the bottom of the outer tank 20, a drainage port 20b is formed. A drainage valve 40 is provided at the drainage port 20b. The drain valve 40 is connected to the drain hose 41. When the drain valve 40 is opened, the water stored in the outer tank 20 is drained out of the machine through the drain hose 41.

  A detergent box 50 is disposed at the upper front of the housing 10. In the detergent box 50, the detergent container 50a in which the detergent is accommodated is accommodated so as to be extractable from the front. The detergent box 50 is connected by a water supply hose 52 to a water supply valve 51 disposed at a rear upper portion in the housing 10. Further, the detergent box 50 is connected to the upper portion of the outer tank 20 by a water injection pipe 53. When the water supply valve 51 is opened, tap water is supplied from the water tap into the outer tank 20 through the water supply hose 52, the detergent box 50 and the water supply pipe 53. At this time, the detergent contained in the detergent container 50 a is pushed into the water and supplied into the outer tub 20.

  Next, the configuration of the drive unit 30 will be described in detail.

  2 and 3 are cross-sectional views showing the configuration of the drive unit 30. FIG. FIG. 2 shows a state in which the drive form of the drive unit 30 is switched to the two-axis drive form, and FIG. 3 shows a state in which the drive form of the drive unit 30 is switched to the uniaxial drive form. FIG. 4 is a front view of the rotor 110 showing the configuration of the rotor 110 of the drive motor 100. As shown in FIG. FIG. 5 is an enlarged perspective view of the rear portion of the bearing unit 500 in which the splines 514 are formed. FIGS. 6A to 6C are diagrams showing the configuration of the clutch body 610 of the clutch mechanism 600, and are a front view, a right side view and a rear view of the clutch body 610, respectively.

  The drive unit 30 includes a drive motor 100, a blade shaft 200, a drum shaft 300, a planetary gear mechanism 400, a bearing unit 500, and a clutch mechanism portion 600. The drive motor 100 generates a torque for driving the stirring body 24 and the drum 22. The blade shaft 200 is rotated by the torque of the drive motor 100, and transmits the rotation to the agitator 24. The planetary gear mechanism 400 decelerates and transmits the rotation of the blade shaft 200, that is, the rotation of the rotor 110 of the drive motor 100 to the drum shaft 300. The planetary gear mechanism 400 corresponds to the reduction gear mechanism of the present invention. The drum shaft 300 rotates coaxially with the blade shaft 200 at a rotational speed decelerated by the planetary gear mechanism 400, and transmits the rotation to the drum 22. The bearing unit 500 rotatably supports the blade shaft 200 and the drum shaft 300. The clutch mechanism 600 rotates the agitating body 24, that is, the blade shaft 200 at a rotational speed equal to the rotational speed of the drive motor 100, and the drum 22, that is, the drum shaft 300 at the rotational speed reduced by the planetary gear mechanism 400. Integrally rotating the rotatable bi-axial drive configuration and the stirring body 24 and the drum 22, that is, the blade shaft 200, the drum shaft 300 and the planetary gear mechanism 400 at the same rotational speed as the drive motor 100 The drive mode of the drive unit 30 is switched between the possible single-axis drive modes.

  Drive motor 100 is an outer rotor type DC brushless motor, and includes a rotor 110 and a stator 120. The rotor 110 is formed in a cylindrical shape with a bottom, and permanent magnets 111 are arranged on the entire inner circumference of the rotor 110. As shown in FIG. 4, a circular boss portion 112 is formed at the central portion of the rotor 110. A boss hole 113 for fixing the blade shaft 200 is formed in the boss portion 112, and an annular engaged recess 114 is formed on the outer periphery of the boss hole 113. The outer circumferential portion of the engaged recess 114 has a concavo-convex portion 114 a along the entire circumference.

  The stator 120 has a winding 121 at its outer periphery. When a drive current is supplied from a motor drive unit described later to the winding 121 of the stator 120, the rotor 110 is rotated.

  The drum shaft 300 has a hollow shape and includes the blade shaft 200 and the planetary gear mechanism 400. The central portion of the drum shaft 300 bulges outward, and the bulged portion becomes a housing portion of the planetary gear mechanism 400.

  The planetary gear mechanism 400 rotates a sun gear 410, an annular internal gear 420 surrounding the sun gear 410, a plurality of sets of planetary gears 430 interposed between the sun gear 410 and the internal gear 420, and the planetary gears 430. And a planetary carrier 440 which holds freely.

  The sun gear 410 is fixed to the blade shaft 200, and the internal gear 420 is fixed to the drum shaft 300. One set of planet gears 430 includes a first gear and a second gear meshing with each other and rotating in opposite directions. The planet carrier 440 includes a carrier shaft 441 extending rearward. The carrier shaft 441 is coaxial with the drum shaft 300, and the inside thereof is hollow for the blade shaft 200 to be inserted.

  The rear end of the blade shaft 200 projects rearward from the carrier shaft 441 and is fixed to the boss hole 113 of the rotor 110.

  The bearing unit 500 is provided with a cylindrical bearing portion 510 at a central portion. Inside the bearing portion 510, rolling bearings 511 and 512 are provided at the front and rear, and a mechanical seal 513 is provided at the front end. The outer peripheral surface of the drum shaft 300 is received by the rolling bearings 511 and 512, and rotates smoothly in the bearing portion 510. Further, the mechanical seal 513 prevents water from entering between the bearing portion 510 and the drum shaft 300. As shown in FIG. 5, splines 514 are formed on the inner surface of the rear end portion of the bearing portion 510 over the entire circumference.

  In the bearing unit 500, a fixing flange portion 520 is formed around the bearing portion 510. A mounting boss 521 is formed at the lower end of the fixed flange 520.

  The bearing unit 500 is fixed to the rear surface of the outer tub 20 at a fixing flange portion 520 by a fixing method such as screwing. The blade shaft 200 and the drum shaft 300 face the inside of the outer tank 20 in a state where the drive unit 30 is attached to the outer tank 20. The drum 22 is fixed to the drum shaft 300, and the agitator 24 is fixed to the blade shaft 200.

  The clutch mechanism portion 600 includes a clutch body 610, a clutch spring 620, a clutch lever 630, a lever support portion 640, a clutch drive device 650, a relay rod 660, and a mounting plate 670.

  As shown in FIGS. 6 (a) to 6 (c), the clutch body 610 has a substantially disk shape. An annular spline 611 is formed on the outer peripheral surface of the front end portion of the clutch body 610. The splines 611 are formed to engage the splines 514 of the bearing unit 500. Further, a flange portion 612 is formed on the outer peripheral surface of the clutch body 610 at the rear of the spline 611. Further, an annular engagement flange portion 613 is formed at the rear end of the clutch body 610. The engagement flange portion 613 has the same shape as the engagement concave portion 114 of the rotor 110, and has an uneven portion 613a on the entire outer circumference. When the engagement flange portion 613 is inserted into the engaged recess 114, the uneven portions 613a and 114a engage with each other.

  Carrier shaft 441 is inserted into shaft hole 614 of clutch body 610. The spline 614 a formed on the inner peripheral surface of the shaft hole 614 engages with the spline 441 a formed on the outer peripheral surface of the carrier shaft 441. Thereby, the clutch body 610 is allowed to move in the front-rear direction with respect to the carrier shaft 441, and the rotation in the circumferential direction is restricted.

  In the clutch body 610, an annular receiving groove 615 is formed on the outside of the shaft hole 614, and the clutch spring 620 is received in the receiving groove 615. One end of the clutch spring 620 is in contact with the rear end portion of the bearing portion 510, and the other end is in contact with the bottom surface of the accommodation groove 615.

  At an upper end portion of the clutch lever 630, a pressing portion 631 which contacts the rear surface of the flange portion 612 of the clutch body 610 and pushes the flange portion 612 forward is formed. The clutch lever 630 is rotatably supported by a support shaft 641 provided on the lever support portion 640. A mounting shaft 632 is formed at the lower end of the clutch lever 630.

  The clutch drive device 650 is disposed below the clutch lever 630. The clutch drive device 650 includes a torque motor 651 and a disk-shaped cam 652 that rotates about a horizontal axis by the torque of the torque motor 651. A cam shaft 653 is provided on the outer periphery of the upper surface of the cam 652. The rotation center of the cam 652 coincides with the center of the mounting shaft 632 of the clutch lever 630 in the front-rear direction.

  The relay rod 660 extends in the vertical direction, and connects the clutch lever 630 and the cam 652. The relay rod 660 is attached at its upper end to the attachment shaft 632 of the clutch lever 630 and at its lower end to the camshaft 653 of the cam 652. A spring 661 is integrally formed on the relay rod 660 at an intermediate position. The spring 661 is a tension spring.

  The lever support portion 640 and the clutch drive device 650 are fixed to the mounting plate 670 by a fixing method such as screwing. The mounting plate 670 is fixed to the mounting boss 521 of the bearing unit 500 by a screw.

  When the drive mode of the drive unit 30 is switched from the single-axis drive mode to the two-axis drive mode, as shown in FIG. 2, the cam 652 is rotated by the torque motor 651 such that the cam shaft 653 is positioned at the lowermost position. . As the cam 652 rotates, the lower end of the clutch lever 630 is pulled downward by the relay rod 660. The clutch lever 630 rotates forward about the support shaft 641, and the pressing portion 631 pushes the clutch body 610 forward. The clutch body 610 moves forward against the elastic force of the clutch spring 620, and the spline 611 of the clutch body 610 and the spline 514 of the bearing unit 500 are engaged.

  The clutch body 610 reaches a position where the spline 611 engages with the spline 514 when the cam shaft 653 moves to the intermediate predetermined position. At this time, the spring 661 of the relay rod 660 is in the natural length state. Since the clutch body 610 does not move to this engagement position, when the cam shaft 653 moves from the predetermined position to the lowermost position, the spring 661 extends downward as shown in FIG. In this case, the clutch lever 630 is pulled forward by the spring 661 so that the pressing force is applied from the pressing portion 631 to the clutch body 610 in the engaged position. This allows the splines 611 to be firmly engaged with the splines 514.

  When the splines 611 and the splines 514 engage, the clutch body 610 is restricted from rotating in the circumferential direction with respect to the bearing unit 500 and can not rotate, so the carrier shaft 441 of the planetary gear mechanism 400, ie, The planet carrier 440 is fixed so as not to rotate. In such a state, when the rotor 110 rotates, the blade shaft 200 rotates at a rotation speed equal to that of the rotor 110, and the agitator 24 connected to the blade shaft 200 also has a rotation speed equal to the rotation speed of the rotor 110 Rotate at. The sun gear 410 is rotated in the planetary gear mechanism 400 as the blade shaft 200 rotates. As described above, since the planet carrier 440 is in a fixed state, the first gear and the second gear of the planetary gear 430 respectively rotate in the same direction and the opposite direction as the sun gear 410, and the internal gear 420 is the sun gear. It rotates in the same direction as 410. Thus, the drum shaft 300 fixed to the internal gear 420 rotates in the same direction as the blade shaft 200 at a rotational speed slower than that of the blade shaft 200, and the drum 22 fixed to the drum shaft 300 is It rotates in the same direction as the stirrer 24 at a slow rotational speed. In other words, the stirrer 24 rotates in the same direction as the drum 22 at a higher rotational speed than the drum 22.

  On the other hand, when the form of the drive unit 30 is switched from the two-axis drive form to the one-axis drive form, as shown in FIG. 3, the cam 652 is rotated by the torque motor 651 so that the cam shaft 653 is positioned uppermost. Ru. When the cam 652 rotates and the cam shaft 653 moves upward, the spring 661 first contracts. When the spring 661 returns to the natural length, thereafter, as the cam shaft 653 moves, the relay rod 660 moves upward, and the lower end of the clutch lever 630 is pushed by the relay rod 660 to move upward. The clutch lever 630 rotates rearward about the support shaft 641, and the pressing portion 631 separates from the flange portion 612 of the clutch body 610. The clutch body 610 is moved rearward by the elastic force of the clutch spring 620, and the engagement flange portion 613 of the clutch body 610 and the engaged recess 114 of the rotor 110 are engaged.

  When the engagement flange portion 613 engages with the engagement recess 114, the circumferential rotation of the clutch body 610 with respect to the rotor 110 is restricted, and the clutch body 610 becomes rotatable together with the rotor 110. In such a state, when the rotor 110 rotates, the blade shaft 200 and the clutch body 610 rotate at a rotational speed equal to the rotational speed of the rotor 110. At this time, in the planetary gear mechanism 400, the sun gear 410 and the planetary carrier 440 rotate at the same rotational speed as the rotor 110. Thereby, the internal gear 420 rotates at the same rotational speed as the sun gear 410 and the planet carrier 440, and the drum shaft 300 fixed to the internal gear 420 rotates at the same rotational speed as the rotor 110. That is, in the drive unit 30, the blade shaft 200, the planetary gear mechanism 400, and the drum shaft 300 rotate integrally. Thereby, the drum 22 and the stirring body 24 rotate integrally.

  FIG. 7 is a block diagram showing the configuration of the drum-type washing machine 1.

  The drum-type washing machine 1 has the control unit 701, the storage unit 702, the operation unit 703, the water level sensor 704, the motor drive unit 705, the water supply drive unit 706, the drainage drive unit 707, the clutch drive unit 708, and the door in addition to the configuration described above. A lock device 709 is provided.

  The operation unit 703 includes a power button 703a, a start button 703b, and a course selection button 703c. The power button 703 a is a button for turning on and off the power of the drum-type washing machine 1. The start button 703 b is a button for starting driving. The course selection button 703 c is a button for selecting an arbitrary driving course from among a plurality of driving courses related to the washing operation. The operation unit 703 outputs an input signal corresponding to the button operated by the user to the control unit 701.

  The water level sensor 704 detects the water level in the outer tank 20, and outputs a water level detection signal corresponding to the detected water level to the control unit 701.

  The motor drive unit 705 supplies a drive current to the drive motor 100 in accordance with the control signal from the control unit 701. The motor drive unit 705 includes a speed sensor that detects the rotational speed of the drive motor 100, an inverter circuit, and the like, and adjusts the drive current so that the drive motor 100 rotates at the rotational speed set by the control unit 701. For example, PWM control is used as motor drive control. In this case, the control unit 701 applies a pulse voltage of the duty ratio determined based on the detected rotational speed to the drive motor 100, whereby a drive current corresponding to the pulse voltage is supplied to the drive motor 100. .

  The water supply drive unit 706 supplies a drive current to the water supply valve 51 in accordance with the control signal from the control unit 701. The drainage drive unit 707 supplies drive current to the drainage valve 40 in accordance with the control signal from the control unit 701.

  The clutch driving device 650 includes a first detection sensor 654 and a second detection sensor 655. The first detection sensor 654 detects that the drive form of the drive unit 30 has been switched to the two-axis drive form, and outputs a detection signal to the control unit 701. The second detection sensor 655 detects that the drive form of the drive unit 30 has been switched to the single-axis drive form, and outputs a detection signal to the control unit 701. The clutch drive unit 708 supplies a drive current to the torque motor 651 in accordance with the control signal output from the control unit 701 based on the detection signals from the first detection sensor 654 and the second detection sensor 655.

  The door lock device 709 locks and unlocks the door 12 in accordance with a control signal from the control unit 701.

  The storage unit 702 includes an EEPROM, a RAM, and the like. The storage unit 702 stores a program for executing a washing operation of various washing operation courses. The storage unit 702 also stores various parameters and various control flags used to execute these programs.

  The control unit 701 controls the motor drive unit 705, the water supply drive unit 706, the drainage drive unit 707, and the clutch drive unit 708 according to the program stored in the storage unit 702 based on the signals from the operation unit 703, the water level sensor 704, and the like. , Controls the door lock device 709 and the like.

  The drum type washing machine 1 performs the washing operation of various operation courses based on the selection operation of the user by the course selection button 703c. In the washing operation, a washing step, an intermediate dewatering step, a rinsing step and a final dewatering step are sequentially performed. Depending on the operation course, the intermediate dehydration step and the rinsing step may be performed twice or more.

  In the washing step and the rinsing step, the drive mode of the drive unit 30 is switched to the two-axis drive mode. Water is stored in the outer tub 20 to a predetermined level not reaching the lower edge of the inlet 11 so that the laundry in the drum 22 is immersed in water, and in this state, the drive motor 100 alternately rotates forward and reverse. Reverse. Thereby, the drum 22 and the stirring body 24 alternately rotate forward and reverse in a state where the rotation speed of the stirring body 24 is faster than the rotation speed of the drum 22. At this time, the drum 22 rotates at a rotational speed at which the centrifugal force acting on the laundry becomes smaller than the gravity.

  The laundry in the drum 22 is shook on the inner circumferential surface of the drum 22 by being scraped up and dropped by the baffle 23. In addition, at the rear of the drum 22, the laundry comes in contact with the blades 24a of the rotating stirring body 24, and the laundry is rubbed by the blades 24a, or the laundry is agitated by the blades 24a. Thereby, the laundry is washed or rinsed.

  As described above, at the time of washing and rinsing, not only the mechanical force by the rotation of the drum 22 but also the mechanical force by the stirring member 24 is applied to the laundry, so improvement in the cleaning performance can be expected. In the intermediate dewatering process and the final dewatering process, the drive mode of the drive unit 30 is switched to the uniaxial drive mode. The drive motor 100, i.e., the drum 22 and the agitator 24, integrally rotates at a rotational speed at which the centrifugal force acting on the laundry in the drum 22 becomes much larger than the gravity. By the action of the centrifugal force, the laundry is pressed against the inner peripheral surface of the drum 22 and dewatered.

  Thus, at the time of dewatering, the drum 22 and the stirring body 24 integrally rotate, so that the laundry stuck to the drum 22 is not stirred by the stirring body 24 and the laundry is dewatered well. it can.

  By the way, as described above, in the drum-type washing machine 1 of the present embodiment, the rotation of the drive motor 100 is decelerated using the planetary gear mechanism 400 and transmitted to the drum 22. In such a configuration, in the two-axis drive mode, when the drive motor 100 is immediately de-energized when the drive motor 100 is stopped, the drive motor 100 tries to stop but the drum 22 continues rotating due to the inertial force. As a result, since a large impact is applied to each gear of the planetary gear mechanism 400, a large noise is likely to be generated from the planetary gear mechanism 400.

  Therefore, in the present embodiment, when the drive motor 100 is stopped in the two-axis drive mode, the control unit 701 executes stop control processing for reducing noise generated from the planetary gear mechanism 400. Hereinafter, the stop control process will be described in detail.

  FIG. 8 is a flowchart showing the stop control process.

  When it is time to stop the drive motor 100 after the drive motor 100 is started, stop control processing is started.

  The control unit 701 sets the rotational speed set as the target rotational speed, that is, the set rotational speed from the rotational speed at the time of operation of the drive motor 100, for example, the rotational speed set to be suitable for washing the laundry in the washing process. The speed is reduced by a predetermined reduction speed V0 (S101). For example, the reduction speed V0 can be set to a rotational speed that is a fraction to a tenth of the rotational speed at the time of operation.

  The control unit 701 controls the motor drive unit 705, and adjusts the drive current supplied to the drive motor 100 so that the rotational speed of the drive motor 100 becomes a new set speed (S102).

  The control unit 701 determines whether the maintenance time T0 has elapsed since the set speed was updated (S103). The maintenance time T0 is a time preset to maintain a new set speed, and is, for example, several hundred milliseconds to several milliseconds. When the maintenance time T0 has elapsed (103: YES), the control unit 701 determines whether the set speed becomes zero due to the next speed reduction (S104). Then, if the set speed is not zero (S104: NO), the control unit 701 returns to step S101, and reduces the set speed again by the reduction speed V0.

  Thus, the process of steps S101 to S103 is repeated until it is determined in step S104 that the set speed becomes zero due to the next speed reduction. Thereafter, when the control unit 701 determines that the set speed becomes zero due to the next speed reduction (S104: YES), the control section 701 stops the supply of the drive current to the drive motor 100 (S105). Thus, the stop control process ends.

  FIGS. 9A and 9B are diagrams schematically showing the movement of the set speed and the movement of the actual rotational speed of the drive motor 100 when the stop control process of FIG. 8 is performed.

  As shown in FIG. 9A, during the washing step and the rinsing step, the drive motor 100 repeats normal rotation and reverse rotation at a washing speed suitable for washing and a rinsing speed suitable for rinsing. At this time, when the drive motor 100 is stopped by performing the stop control process of FIG. 8, the set speed is decreased by the reduction speed V0 every maintenance time T0. As a result, when the drive motor 100 is stopped, the drive current supplied to the drive motor 100 does not immediately become zero but gradually decreases, and as shown in FIG. While the rotational speed is gradually reduced, it eventually reaches a stop. Finally, when the drive motor 100 is de-energized, that is, when the drive current is made zero, the rotational speed of the drive motor 100 is reduced to a very low rotational speed, and this causes the drum 22 to The rotational speed is also reduced to a very low rotational speed. Therefore, even if the drive motor 100 is stopped by stopping the power supply in this state, the inertial force acting on the drum 22 is small, so that no large impact is applied to the planetary gear mechanism 400, and the generation of abnormal noise can be suppressed.

  When the drive form of drive unit 30 is a single-axis drive form, the rotation of drive motor 100 is transmitted to drum shaft 300 without being decelerated by planetary gear mechanism 400. Abnormal noise of the gear mechanism 400 is unlikely to occur. Therefore, the control unit 701 does not execute the stop control process of FIG. 8 when stopping the rotation of the drum 22, that is, the drive motor 100 when the drive mode is switched to the single-axis drive mode, such as in the dehydration step. The motor drive unit 705 is controlled to immediately stop the supply of the drive current to the drive motor 100. Thus, in the single-axis drive mode, it is possible to prevent the time required to stop the rotation of the drum 22 from being prolonged unnecessarily.

<Effect of the embodiment>
As described above, according to the present embodiment, when the drive motor 100 is operated in the two-axis drive mode, when the drive motor 100 is stopped, the drive is performed so as to reach the stop after the rotational speed gradually decreases. Since the motor 100 is controlled, the impact applied to the planetary gear mechanism 400 when the drive motor 100 is stopped can be reduced, and the generation of abnormal noise of the planetary gear mechanism 400 can be reduced.

  In addition, when the drum 22 is rapidly stopped, vibration is likely to occur in the drum 22. However, according to the above embodiment, since the drum 22 can be stopped slowly, the generation of vibration can be suppressed.

  Furthermore, according to the above-described embodiment, in order to gradually decelerate the drive motor 100, motor control is performed to reduce the set speed by a fixed speed every fixed time. The smaller the amount of load in the drum 22, the easier it is for the drum 22, ie, the drive motor 100 to decelerate faster, but with such motor control, as shown in FIGS. 10 (a) and 10 (b). Alternatively, the rotational speed of the drive motor 100 can be reduced by taking a similar time. As a result, the generation of abnormal noise of the planetary gear mechanism 400 can be favorably reduced without being influenced by the load amount or the like.

<Modification example>
As mentioned above, although the embodiment of the present invention was described, the present invention is not limited at all by the above-mentioned embodiment etc. In addition, the embodiment of the present invention can be variously modified in addition to the above. is there.

  For example, in the above embodiment, the rotor 110 of the drive motor 100 is directly coupled to the stirring body 24 by the blade shaft 200, and the stirring body 24 rotates at a rotational speed equal to the rotational speed of the drive motor 100. However, similarly to the drum 22, a speed reduction mechanism using gears may be interposed between the stirring body 24 and the drive motor 100. In this case, by setting the speed reduction ratio of the speed reduction mechanism used for the stirring body 24 to be smaller than the speed reduction ratio of the planetary gear mechanism 400, the stirring body 24 can be rotated faster than the drum 22.

  Furthermore, in the above embodiment, the drum 22 rotates about an inclined axis inclined with respect to the horizontal direction. However, the drum-type washing machine 1 may be configured such that the drum 22 rotates about a horizontal axis.

  Furthermore, although the drum-type washing machine 1 of the said embodiment is not provided with the drying function, this invention can also be applied to the drum-type washing machine provided with the drying function, ie, a drum-type washing-drying machine.

  Besides the above, the embodiment of the present invention can be variously modified as appropriate within the scope of the technical idea shown in the claims.

10 enclosures
20 outer tank
22 drums
24 Stirring body (rotary body)
24a Feather (protruding part)
30 Drive unit (drive unit)
100 drive motor
400 Planetary gear mechanism (speed reduction mechanism)
600 clutch mechanism
701 control unit
705 Motor drive unit

Claims (2)

An outer tank disposed in the housing,
A drum disposed within the outer vessel and rotatable about a horizontal axis or an inclined axis inclined relative to the horizontal direction;
A rotating body disposed at the rear of the drum and having protrusions on its surface that contact the laundry;
A drive unit including a drive motor and a reduction mechanism for reducing the rotation of the drive motor by means of gears and transmitting it to the drum;
A motor drive unit for supplying a drive current to the drive motor;
A control unit that controls the motor drive unit;
The driving unit is configured to rotate the drum and the rotating body separately at different rotational speeds by decelerating the rotation of the driving motor by the reduction mechanism and transmitting the driving mode of the driving unit to the drum. Between an axial drive form and a uniaxial drive form in which the drum and the rotating body are integrally rotated at the same rotational speed by transmitting rotation of the drive motor to the drum without decelerating the reduction mechanism. Further including a clutch mechanism unit for switching
The control unit
In the washing step and the rinsing step, the motor drive unit is controlled to rotate the drive motor forward and reverse, thereby rotating the drum forward and reverse.
When stopping the rotation of the drum decelerated by the decelerating mechanism between the normal rotation and the reverse rotation, the motor drive unit is controlled such that a drive current supplied to the drive motor is gradually reduced.
Drum-type washing machine characterized by. In the drum type washing machine according to claim 1,
The motor drive unit adjusts a drive current according to the rotation speed of the drive motor set by the control unit,
The control unit sets the rotational speed of the drive motor to decrease by a predetermined speed every predetermined time when stopping the rotation of the drum decelerated by the reduction mechanism.
Drum-type washing machine characterized by.

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