JP5851111B2 - Drum washing machine - Google Patents

Description

  The present embodiment relates to a drum type washing machine.

  For example, in a drum-type washing machine, a water tank disposed in an outer box is elastically supported by a plurality of suspensions between the outer box and the water tank, thereby reducing vibration of the water tank accompanying the rotation of the drum. It is like that.

In recent years, there is a concept of using a damper having a variable damping force as this type of suspension, and the damper is filled with a magnetorheological fluid as a functional fluid (see, for example, Patent Document 1). Specifically, for example, a rod is provided in a cylinder so as to be able to reciprocate, and a coil for generating a magnetic field is disposed on a piston at the tip of the rod. A gap through which the magnetorheological fluid moves is formed between the outer periphery of the stone and the inner periphery of the cylinder. And if a water tank vibrates up and down, a piston and a cylinder will vibrate relatively, damping force will be given with resistance by the viscosity of a magnetorheological fluid, and vibration of a water tank will be attenuated.
Here, when the coil is energized, a magnetic field is generated to apply the magnetic field to the magnetorheological fluid, and the viscosity of the magnetorheological fluid increases. As a result, the resistance between the piston and the cylinder increases and the piston becomes relatively difficult to move, so that the damping force increases.

JP 2008-295906 A

A drum-type washing machine has a plurality of resonance points (resonance frequencies), and when the drum rotation speed is increased, resonance occurs such that the water tank mainly vibrates in the vertical direction and resonance that vibrates in the left-right direction. To do.
However, the conventional drum type washing machine does not necessarily correspond to the vibration mode of the water tank, and the effect of suppressing vibration and noise by the damper is not sufficient.
Therefore, a drum type washing machine having a damper and capable of more effectively suppressing vibration and noise is provided.

The drum type washing machine according to the present embodiment is provided between an outer box, a water tank provided in the outer box, a drum rotatably provided in the water tank, and the outer box and the water tank. And a damper for damping the vibration of the water tank, and a control means for variably controlling the damping force of the damper. Wherein the control unit changes the damping force of the damper during the said drum rotation 1 in the dehydration step is performed periodically repeated controlled in accordance with the rotation of the drum for the variable control.

The 1st Embodiment is a figure showing the relation between the rotation cycle of the drum and the damping force of the left and right dampers Longitudinal side view of drum-type washing machine Vertical section of the entire suspension Block diagram showing electrical configuration The figure which shows the relationship between the phase of an unbalance position, and q-axis current (A) is a figure for demonstrating the relationship between the rotation speed of a drum and the amplitude of the horizontal direction of a water tank, (b) is a schematic diagram which shows the amplitude of the said horizontal direction in a washing machine. (A) is a figure for demonstrating the relationship between the rotation speed of a drum and the amplitude of the up-down direction of a water tank, (b) is a schematic diagram which shows the said up-down direction amplitude in a washing machine. A diagram for explaining the horizontal and vertical amplitudes of the water tank and the switching timing of the control pattern FIG. 1 equivalent diagram showing the damping force of the damper after switching the control pattern The schematic diagram which shows 2nd Embodiment and shows the relationship between the phase of an unbalance position, and the output of a vibration detection means. This is for explaining the relationship between the phase of the unbalance position, the q-axis current, and the output of the vibration detection means. (A) is when the drum rotation is 100 rpm, (b) is the state when the drum rotation is 200 rpm. Figure showing

<First Embodiment>
The first embodiment will be described below with reference to FIGS. 1 to 9. FIG. 2 shows the overall structure of a drum-type washing machine (hereinafter simply referred to as a washing machine). As shown in the figure, the outer box 1 has a box shape that forms the outer shell of the washing machine, and a laundry doorway 2 is formed at the center of the front side (right side of the figure). A door 3 that opens and closes the doorway 2 is provided. In addition, an operation panel 4 is provided at the upper part of the front surface of the outer box 1, and a control device 5 for operation control is provided on the back side.

Inside the outer box 1, a horizontal-axis cylindrical water tank 6 whose axis is directed in the front-rear direction is disposed. The aquarium 6 is elastically supported on the bottom plate 1a of the outer box 1 in an upwardly inclined state by a plurality of suspensions (for example, a pair of left and right). The specific configuration of the suspensions 7a and 7b of this embodiment will be described later.
A motor 8 made of, for example, a brushless DC motor is disposed at the center of the rear end side of the water tank 6. The motor 8 is of the outer rotor type, and a rotating shaft (not shown) attached to the central portion of the rotor 8a is inserted into the water tank 6 through the bearing bracket 9 and connected to the central portion on the rear end side of the drum 10. ing.

  The drum 10 is disposed inside the water tub 6 and functions as a washing tub for storing laundry. The drum 10 is formed in a horizontal cylindrical shape whose axis is directed in the front-rear direction, and is connected to the rotating shaft of the motor 8 and supported in a forwardly inclined state coaxial with the water tank 6. Thus, the drum 10 is directly driven by using the motor 8 as a driving means. In the drum 10, a large number of small holes 11 that allow water and air to pass therethrough are formed in the peripheral side portion (body portion) of the drum 10, while the water tank 6 is configured to be substantially non-porous and capable of storing water. ing. The drum 10 and the water tank 6 have openings 12 and 13 on their front portions. An annular bellows 14 is mounted between the opening 13 of the water tub 6 and the laundry entrance 2. Thereby, the laundry entrance 2 is connected to the inside of the drum 10 through the bellows 14, the opening 13 of the water tank 6, and the opening 12 of the drum 10. A drain pipe 15 is connected to the lowest part of the water tank 6 through a drain valve 15a.

  In the washing machine, a drying unit 16 is disposed as a drying means from the back side of the water tub 6 to the upper side and the front side. The drying unit 16 is composed of a blower 18, a heating device 19, and a circulation duct 17 having a dehumidifying means (not shown). The drying unit 16 dehumidifies moisture in the air discharged from the water tank 6 and then heats it. The laundry in the drum 10 is dried by circulating the water back into the water tank 6.

  Vibration sensors 20a and 20b (see FIGS. 2 and 4) are disposed at the front and rear of the upper part of the water tank 6, respectively. Each of the vibration sensors 20a and 20b is composed of, for example, an acceleration sensor. If there is an imbalance when the drum 10 rotates, the vibration of the water tank 6 due to the vibration of the drum 10 is detected. As will be described in detail later, the vibration sensors 20 a and 20 b and the control device 5 are configured as means for detecting the rotation period of the drum 10 and detecting vibrations of the water tank 6.

The configuration of the suspensions 7a and 7b will be described.
As shown in FIG. 2, the suspensions 7 a and 7 b are inserted into the cylinder device 30 attached to the attachment plate 21 on the bottom plate 1 a side of the outer box 1, and can be vertically moved into the cylinder device 30. A shaft 24 attached to the side attachment plate 6a, and a coil spring 25 attached between the shaft 24 and the cylinder device 30. The cylinder device 30 and the shaft 24 constitute the damper 23 of the present embodiment, and are arranged symmetrically with respect to the water tank 6 together with the coil spring 25 (see FIG. 6B). Thus, a pair of left and right suspensions 7a and 7b that connect the outer box 1 and the water tank 6 in the vertical direction are configured.

  Specifically, the cylinder device 30 includes a cylindrical iron cylinder 22 as shown in FIG. 3, a cylinder connecting portion 30 a attached to the lower end of the cylinder 22, and a cylinder 22, which will be described later. The magnetic field generator 40 is provided. The cylinder device 30 is fixed to the mounting plate 21 of the bottom plate 1a by fastening the connecting portion 30a to the mounting plate 21 of the bottom plate 1a (see FIG. 2) with a nut 27 via an elastic seat plate 26 such as rubber. Installation is fixed.

  On the other hand, the shaft 24 includes a shaft main portion 24a inserted into the cylinder device 30 and a shaft connecting portion 24b integrally connected to an upper end portion thereof. In the shaft 24, at least the shaft main portion 24a is made of an iron magnetic material. The connecting portion 24b is fastened to the mounting plate 6a of the aquarium 6 with a nut 29 via an elastic seat plate 28 or the like such as rubber, so that the shaft 24 follows the vibration of the aquarium 6 and integrally moves in the vertical direction or left and right. The connection structure vibrates in the direction.

As shown in FIG. 3, the lower end portion of the coil spring 25 is supported by the upper end portion of the cylinder device 30, and the upper end portion is received by a disc-shaped spring receiving portion 49 disposed at the upper portion of the shaft 24. . Accordingly, the coil spring 25 is stretched in a state in which the shaft 24 is urged so as to pull out the shaft 24 outward from the cylinder device 30.
In the cylinder 22 of the cylinder device 30, bearing means 33 and 39 for supporting the shaft 24 linearly so as to reciprocate in the vertical direction are disposed and fixed at the upper and lower portions. The magnetic field generator 40, the magnetorheological fluid, and the like are accommodated in an intermediate portion sandwiched between the pair of upper and lower bearing means 33 and 39.

  The lower bearing means 33 includes a bearing holding member 31 that is housed and fixed in an intermediate portion in the vertical direction in the cylinder 22, and a bearing 33 a that is housed and fixed in the bearing holding member 31. The bearing holding member 31 is formed in a hollow cylindrical shape from, for example, a nonmagnetic material made of aluminum, and has a groove portion 32 extending in the circumferential direction on the outer peripheral portion thereof. The bearing holding member 31 is fixed in the cylinder 22 by caulking the peripheral wall portion of the cylinder 22 so that the portion corresponding to the groove portion 32 protrudes inward. The bearing 33a is a sintered oil-impregnated bearing formed annularly from a copper-based nonmagnetic material. The bearing 33 a is configured as a sliding bearing that is fitted and fixed to the inner peripheral portion of the bearing holding member 31 and supports the shaft 24 so as to be capable of reciprocating in the vertical direction that is the axial direction. One sealing member 38 c is press-fitted and held on the upper surface side of the bearing 33 a in the bearing holding member 31. A stop ring 34 is attached to the lower end of the shaft 24. The stop ring 34 is in contact with the lower surface of the bearing holding member 31 so as to prevent the shaft 24 from moving upward and coming off.

  The upper bearing means 39 includes a bearing holding member 35 housed and fixed inside the upper end portion of the cylinder 22, and a bearing 39 a housed and fixed in the bearing holding member 35. The bearing holding member 35 is formed in a hollow cylindrical shape from a nonmagnetic material made of aluminum, for example, like the lower bearing holding member 31. The bearing holding member 35 has a stepped shape with a lower half portion having a large diameter and an upper half portion having a small diameter, and has a groove portion 36 formed on the outer surface of the large diameter cylindrical portion 35a over the entire circumference. The peripheral wall portion of the cylinder 22 fixes the bearing holding member 35 to the upper end portion of the cylinder 22 by causing a portion corresponding to the groove portion 36 to protrude inward by, for example, rolling caulking. An elastic O-ring 37 is attached to the groove portion 36. The O-ring 37 is held in close contact by the caulking with respect to the groove portion 36 so as to securely fix the bearing holding member 35 and prevent water from entering the cylinder 22.

  In the outer peripheral portion of the bearing holding member 35, a step portion 35 c formed at the boundary between the small diameter cylindrical portion 35 b and the large diameter cylindrical portion 35 a supports the lower end portion of the coil spring 25. The bearing holding member 35 also functions as a spring holding member that holds the outer surface of the small-diameter cylindrical portion 35 b from the side with respect to the lower end inner diameter of the coil spring 25. The bearing 39a is a sintered oil-impregnated bearing formed in a ring shape from a non-magnetic material, like the bearing 33a. In addition to the bearing 39a, for example, two sealing members 38a and 38b are press-fitted and held in the hollow inside of the bearing holding member 35, which is positioned below the bearing 39a. Each of the sealing members 38a and 38b and the sealing member 38c is a so-called springless oil seal in which a metal ring is insert-molded into a rubber main body having a sealing lip. The metal ring is made of, for example, a nonmagnetic material made of aluminum, unlike an iron seal in a general oil seal. Further, the bearing holding member 35 has a stepped hollow shape with different diameters, and the sealing members 38a and 38b are vertically connected to the large-diameter internal portion 35d corresponding to the large-diameter cylindrical portion 35a. It is press-fitted. In the hollow interior of the bearing holding member 35, a small-diameter interior 35e is formed which is continuous with the upper portion of the large-diameter interior 35d and into which the bearing 39a is press-fitted with a smaller diameter. Further, the bearing holding member 35 is formed with an insertion hole 35f having a smaller diameter so as to form a stepped portion that also serves to prevent the bearing 39a from coming off upward, and the shaft 24 is inserted into the insertion hole 35f. Has been.

  The magnetic field generator 40 includes bobbins 43U and 43D arranged in two upper and lower stages around the shaft 24, coils 41U and 41D wound around the bobbins 43U and 43D, and three yokes 42a to 42c. . The bobbins 43U and 43D form a cylindrical gap between the bobbin 43U and 43D and the outer peripheral surface of the shaft 24 inserted through the hollow portion at the center thereof. The yoke 42a and the yoke 42c are disposed on the upper side of the bobbin 43U and the lower side of the bobbin 43D, and the yoke 42b is disposed between the bobbin 43U and the bobbin 43D. The hollow portions of the yokes 42a to 42c have a narrow gap (for example, about 0.4 mm) between the outer periphery of the shaft 24 and communicate with the gap formed by the bobbins 43U and 43D in the vertical direction. A cylindrical gap extending in the direction is formed. The upper and lower coils 41U and 41D are connected in series with each other.

  The magnetic field generator 40 is formed of, for example, a thermoplastic resin (nylon, PBT, PET, PP) with the coils 41U and 41D wound around the bobbins 43U and 43D and the yokes 42a to 42c arranged as described above. Etc.) is resin molded (see the resin mold portion 44 in the figure). Thereby, the bobbins 43U and 43D, the coils 41U and 41D, and the yokes 42a to 42c in the magnetic field generator 40 are integrated. Therefore, the magnetic field generation device 40 forms a gap around the shaft 24, and the upper and lower ends of the gap are sealed by the upper and lower sealing members 38b and 38c to form a cylindrical housing portion 50. In addition, the uppermost sealing member 38a reliably seals the housing portion 50 in a double sealed state and reliably prevents water from entering from the upper side.

  A magnetorheological fluid 45 is accommodated in the accommodating portion 50. The magnetorheological fluid 45 is a fluid whose viscosity changes when electric energy is applied, and its viscosity characteristics change according to the strength of the magnetic field (magnetic field). For example, iron is contained in a base oil mainly composed of polyalphaolefin oil. It is made of a dispersion of ferromagnetic particles such as carbonyl iron, and has a characteristic that when the magnetic field is applied, the ferromagnetic particles form chain clusters to increase the apparent viscosity.

  The magnetorheological fluid 45 is supplied to the container 50 from an injection port (not shown) in a state in which the magnetic field generator 40 and the bearing means 33 and 39 are inserted into the shaft 24 to form the container 50. Is done. Although detailed illustration is omitted, the magnetorheological fluid 45 is, for example, about 70% to 80% of the total volume of the accommodating portion 50, and the remaining 20% to 30% is occupied by air 48 (shown in white in the figure). It is enclosed. The axial length L occupied by the air 48 in the housing 50 is set to be smaller than the stroke of the shaft 24 that moves up and down based on the vibration at the initial stage of the dehydration operation (resonance region R1 described later).

  That is, in order to draw out the damping action by the magnetorheological fluid 45 as much as possible, the axial length L is set to 10 mm or less if the stroke of the shaft 24 due to vibration at the time of dehydration activation is 10 mm. Thus, although the accommodating portion 50 is originally a narrow gap, since the air 48 occupies the upper layer portion thereof, the amount of use of the magnetic viscous fluid 45 can be reduced as much as possible. Further, as the water tank 6 vibrates, the shaft 24 moves up and down beyond the range in which the air 48 is in contact, so that it can come into contact with the lower layer magnetorheological fluid 45 and the magnetorheological fluid 45 is reduced. However, the above-described damping action can be promoted.

  With the magnetic field generator 40 and the like assembled to the shaft 24 as described above, these members are inserted together with the shaft 24 to a predetermined position of the cylinder 22. In this state, the parts corresponding to the grooves 32 and 36 of the bearing holding members 31 and 35 in the cylinder 22 are caulked. Thereby, the member in the cylinder 22 is fixed integrally, and the cylinder apparatus 30 is comprised. A hollow portion 30b closed by a connecting portion 30a is formed at the lower portion of the cylinder device 30 to secure a space that allows the shaft 24 to move downward. Further, the coil device 25 is assembled into the cylinder device 30 and assembled as suspensions 7a and 7b. In this case, the coil spring 25 is mounted between the stepped portion 35c of the bearing holding member 35 and the spring receiving portion 49 in a state where the elastic force is accumulated so as to be compressed.

  Thus, the suspensions 7a and 7b are arranged on the left and right sides of the water tank 6 with the cylinder device 30 positioned on the outer box 1 side in the vertical direction between the bottom plate 1a of the outer box 1 and the water tank 6 as described above. The The suspensions 7a and 7b are arranged so as to extend substantially in the vertical direction, but strictly speaking, when exaggerated, the suspensions 7a and 7b have a “C” shape in a front view (see FIG. 6B). Are inclined such that the distance between them increases toward the bottom. The shaft 24, the cylinder 22, the magnetic field generator 40, the magnetorheological fluid 45, etc. constitute a damper 23.

  The two lead wires 46 drawn from the coils 41U and 41D are led out to the outside through a bush 47 attached to the cylinder 22. The lead wire 46 is connected to the control device 5 via a drive circuit (not shown), and can control power interruption to the coil 41 of the magnetic field generation device 40. Broken line arrows A1 and A2 shown in FIG. 3 indicate magnetic circuits generated around the coils 41U and 41D as the coils 41U and 41D are energized, and indicate the directions of the magnetic fields. The shaft 24, the yokes 42a to 42c, and the cylinder 22 constituting the magnetic circuits A1 and A2 are all made of an iron magnetic material.

  FIG. 4 is a block diagram showing an electrical configuration. The control device 5 is mainly composed of a microcomputer, and is a control means for controlling the overall operation of the washing machine including the washing process to the drying process for washing, dehydrating and drying the laundry in the drum 10. The control device 5 includes, for example, a ROM 51a, a RAM 51b, and an EEPROM 51c as storage means. The ROM 51a stores a control program and various data for controlling the entire operation such as a washing operation in the washing machine.

  The control device 5 includes various operation signals from an operation unit 52 including various operation switches of the operation panel 4, a rotation detection signal from a rotation sensor 53 provided to detect the rotation of the motor 8, and the water tank 6. Vibration detection signals from the vibration sensors 20a and 20b provided to detect vibration, a current detection signal from a current sensor 54 provided to detect the current flowing through the motor 8, and the like are input. Based on the detection signal from the rotation sensor 53, the control device 5 performs a calculation to divide the number of rotations of the motor 8 (drum 10) by the required detection time, and detects the rotation speed of the drum 10 based on the calculation. Further, the control device 5 calculates the amplitude (vibration value) based on the detection values of the vibration sensors 20a and 20b, or calculates a q-axis current described later from the current sensor 54 based on the current detection signal.

  The control device 5 performs vector control on the motor 8. In the vector control, the current flowing through the armature winding is separated into the magnetic flux direction of the permanent magnet, which is a field, and the direction orthogonal thereto, and these are adjusted independently to control the magnetic flux and the generated torque. For the current control, a current value represented by a coordinate system rotating with the rotor 8a of the motor 8, that is, a so-called dq coordinate system is used. The d axis is a magnetic flux direction formed by a permanent magnet attached to the rotor. Is a direction orthogonal to the d-axis. The q-axis current that is the q-axis component of the current flowing through the winding is a component that generates rotational torque (torque component current), and the d-axis current that is the d-axis component is a component that creates magnetic flux (excitation or magnetization component). Current). Therefore, an unbalanced load (that is, an unbalanced state) due to the unbalance of the laundry in the drum 10 occurs, and the q-axis current increases as the rotational torque increases. Therefore, the magnitude of torque fluctuation of the motor 8 can be detected based on the magnitude of the q-axis current.

Here, in FIG. 5, assuming that the position where the laundry W is unevenly distributed in the drum 10 is 0 degree, the torque fluctuation when the drum 10 rotates, for example, in the clockwise direction in front view is equivalent to two rotations (360 degrees × 2 ). Torque shown by the curve T ₁₀₀ in the figure, the relationship between gravity acting on the laundry W, a maximum at 180 ° laundry W in the drum 10 is in the uppermost position, the laundry W is the lowermost position The minimum is 360 degrees (0 degrees). Further, since the torque fluctuates so as to draw a periodic curve for each rotation of the drum 10 as shown in the figure, an unbalanced phase can be detected. Thus, the current sensor 54 and the control device 5 are configured as torque fluctuation detecting means for detecting torque fluctuation of the motor 8 and rotation period detecting means for detecting the rotation period of the drum 10.

  Then, the control device 5 supplies water into the water tank 6 and the display unit 55 for displaying the setting contents based on the input signal and detection signal described above and the control program and data stored in advance in the ROM 51a and the EEPROM 56c. A water supply valve 56, a motor 8, a drain valve 15a, a motor 18b (see FIG. 1) for driving a blower blade 18a (see FIG. 1) of the blower 18, and a heater 19a (see FIG. And a drive control signal is supplied to the drive circuit 57 that drives the coils 41U and 41D.

  As shown in FIGS. 1 and 6, the control device 5 according to the present embodiment performs variable control for the left suspension 7 a and the right suspension 7 b separately, and performs the damping for each rotation of the drum 10. Perform periodic control to increase or decrease the force.

  Specifically, for example, when the drum 10 makes one rotation in the clockwise direction, in the left suspension 7a, as shown in FIG. 1 (a), the coil 41U and the unbalanced phase are in the range of 0 to 90 degrees. 41D (hereinafter simply referred to as a coil 41) is energized, and the coil 41 is also energized in the range of 180 degrees to 270 degrees. In the right suspension 7b, as shown in FIG. 1B, the coil 41 is energized when the unbalanced phase is in the range of 90 to 180 degrees, and the coil 41 is also energized in the range of 270 to 360 degrees. That is, the control device 5 turns the drum 10 on and off every ¼ rotation so that the damping force increases alternately between the left suspension 7a and the right suspension 7b based on the current detection signal from the current sensor 54. Repeat the control. As will be described in the following description of the operation, this periodic control can increase the vibration suppressing effect as much as possible in the low speed region.

Next, the operation of the above configuration will be described with reference to FIGS.
First, when the user turns on a power switch (not shown) of the operation unit 52 of the washing machine and performs a setting operation of the washing operation, the control device 5 performs the washing operation in the order of the washing process to the drying process, for example. Run. The washing operation of the present embodiment is a general term for an operation including any one of the washing process to the drying process, and includes various washing operations.

  The energization control to the coil 41 of the suspensions 7a and 7b is set corresponding to a period during which the vibration of the water tank 6 increases during the washing operation. In the following, description will be made by taking as an example a process of increasing the rotation speed of the motor 8 during acceleration in the dehydration process, for example, from the start of rotation of the drum 10 until reaching a steady rotation speed.

  In the dehydration process, the rotational speed of the motor 8 (drum 10) is increased stepwise, and the water remaining on the laundry is spun off and discharged by centrifugal force. In this rotational speed increasing process, primary resonance is generated in which the water tank 6 vibrates mainly in the left-right direction, particularly in the region indicated by R1 in FIG. Here, as schematically shown in FIG. 6 (b), the suspensions 7 a and 7 b respond to the left and right vibration of the water tank 6 through the shaft 24 connected to the water tank 6, and the lower end of the suspension (the bottom plate). It swings to the left and right with the mounting portion 1a as a fulcrum. In this case, the viscosity of the magnetorheological fluid 45 in the damper 23 gives a frictional resistance to the reciprocating motion of the shaft 24 and quickly attenuates the vibration amplitude of the water tank 6.

  In addition, when the dehydration process is started, the control device 5 applies to the left and right suspensions 7a and 7b every ¼ rotation of the drum 10 based on the current detection signal from the current sensor 54, as shown in FIG. In addition, control for repeating energization and disconnection is performed so that the energization of the coil 41 is alternately switched. As described above, when the coil 41 is energized to generate a magnetic field, the magnetic circuits A1 and A2 are formed around the coil 41, the viscosity of the magnetorheological fluid 45 is rapidly increased, and the resistance to the shaft 24 is increased.

  Further, in this case, as shown in FIG. 1, the on / off control for the coil 41 of the left suspension 7a is performed twice while the drum 10 makes one rotation corresponding to the unbalanced phase, and the energization is performed. On / off control to the coil 41 of the right suspension 7b is performed twice so that power is alternately supplied. By executing such variable control periodically and repeatedly according to the rotation of the drum 10, the damping force of each damper 23 is alternately increased in the suspensions 7a and 7b. Thus, in the present embodiment, when the drum 10 rotates clockwise when viewed from the front, the damping force of the left suspension 7a is relatively increased when the unbalanced phase is in the range of 0 to 90 degrees (FIG. 1). (See (a)), the damping force of the right suspension 7b is relatively lowered (see FIG. 1 (b)), and the damping force of each damper 23 of both 7a and 7b is alternately changed every 90 degrees. Perform variable control to increase.

  Here, in FIG. 6A, the curve S1c indicated by the lower two-dot chain line indicates the vibration amplitude in the left-right direction of the water tank 6 when the above-described periodic control is executed. A curve S2 indicated by a solid line on the upper side indicates the vibration amplitude in the left-right direction when the coil 41 of both suspensions 7a and 7b is continuously energized (see FIG. 9) in the process of increasing the rotational speed of the motor 8. Yes. As is clear from the figure, with respect to the vibration in the horizontal direction of the water tank 6, the periodic control of the curve S1c has a higher damping effect (reduction effect) even though the energization time is halved. ) This is because the suppression effect of the horizontal vibration of the water tank 6 is enhanced by performing variable control that changes the damping force of the damper 23 while the drum 10 makes one rotation in correspondence with the phase of unbalance. It can be understood.

On the other hand, in FIG. 7A, a curve S3c indicated by an upper two-dot chain line indicates the vertical vibration amplitude of the water tank 6 when periodic control is executed. A curve S4 indicated by a solid line on the lower side indicates the vibration amplitude in the vertical direction when the energization is continued for the coils 41U and 41D of both suspensions 7a and 7b in the rotational speed increasing process of the motor 8 (see FIG. 9). Is shown. As is clear from the figure, regarding the vibration in the vertical direction of the water tank 6, the vibration in the vertical direction as the stroke direction is further suppressed when the damping force of each damper 23 is kept high. Moreover, this tendency becomes more prominent as the rotational speed of the drum 10 increases. Moreover, in FIG. 8 which shows said curve S1c-S4, in primary resonance area | region R1, the amplitude of the water tank 6 in the left-right direction is the largest, and the amplitude of the up-down direction is comparatively small. Thereafter, as the rotational speed of the drum 10 increases, the amplitude in the left-right direction gradually decreases, while the amplitude in the vertical direction gradually increases.

Therefore, the control device 5 switches the control patterns of the suspensions 7a and 7b at a predetermined rotational speed indicated by Vc in FIG. 8 in order to effectively suppress the horizontal vibration and the vertical vibration of the water tank 6. That is, the ROM 51a stores the predetermined rotation speed Vc in advance, and the rotation speed is, for example, the rotation speed at which the horizontal resonance of the water tank 6 occurs (see the primary resonance region R1) and the vertical resonance. Is set to a value between the rotation speed (see the secondary resonance region R2). Then, when the control device 5 determines that the rotational speed of the drum 10 has reached Vc based on the detection signal from the rotation sensor 53, the control device 5 detects the suspensions 7a and 7b from the periodic control shown in FIG. The coil 41 is energized and switched to control (see FIG. 9) that continues the energized state.

  Thus, as indicated by a broken line in FIG. 8, in the primary resonance region R1 of the dehydration process in which the resonance of the water tank 6 appears, the control device 5 halves the substantial energization time by executing periodic power interruption control. It is possible to effectively suppress the vibration in the left-right direction (see curve S1c). Further, when the rotation speed of the drum 10 becomes equal to or higher than Vc, the control device 5 continues energizing the coils 41 of both suspensions 7a and 7b as shown in FIG. Thereby, the damping force of the damper 23 of each suspension 7a, 7b can be set high so that the vertical vibration of the water tank 6 can be reduced (see curve S4 in FIG. 8). In this way, even in the high speed region after the secondary resonance region R2 (speed region above Vc), the occurrence of resonance in the water tank 6 is avoided, the rising performance of the drum 10 rotation is improved, and the steady rotational speed is increased. Can be made.

  The resonance region of the present embodiment is a region near the resonance point including the resonance point (resonance frequency), and the primary resonance region R1 is a relatively low frequency region among the plurality of resonance points existing in the washing machine. Is a resonance region belonging to.

  As described above, the dampers 23 of the suspensions 7a and 7b that are provided between the outer case 1 and the water tank 6 and attenuate the vibration of the water tank 6 and the control device 5 that variably controls the damping force of the damper 23 are provided. The control device 5 is configured to change the damping force of the damper 23 during one rotation of the drum 10 and to execute control that repeats the variable control periodically according to the rotation of the drum 10.

  According to this, in the washing machine, torque fluctuation occurs during one rotation of the drum 10 due to the weight of the laundry W in the drum 10, so that the damping force of the damper 23 can be varied according to the cycle. Thus, vibration of the water tank 6 can be effectively suppressed. That is, the vibration suppression effect can be enhanced by performing fine control to change the damping force during one rotation of the drum 10 so as to correspond to the periodic torque fluctuation accompanying the rotation of the drum 10. .

  In addition, in a general suspension, since the shaft is arranged in the vertical direction to support the water tank, the vibration reduction effect inherent to the damper can be expected for the vibration in the vertical direction of the water tank, The vibration reduction effect with respect to other vibrations (lateral vibrations) was not sufficient. In this regard, as in the present embodiment, when the water tank 6 is viewed from the front (axial direction), the left and right dampers 23 perform periodic control in a configuration including a pair of left and right suspensions 7a and 7b. Thereby, the vibration of the left-right direction of the said water tank 6 can also be suppressed effectively.

The controller 5 includes a rotation cycle detection unit that detects the rotation cycle of the drum 10, and the control device 5 performs periodic control of the damper 23 based on the rotation cycle detected by the rotation cycle detection unit.
According to this, the damping force of the damper 23 can be varied in accordance with the unbalanced phase, that is, the actual rotation cycle of the drum 10 by the rotation cycle detection means. Therefore, the effect of suppressing vibration and noise can be further enhanced. The rotation period detection means is not limited to the current sensor 54 or the control device 5, but may be configured using vibration sensors 20a and 20b as described in the second embodiment.

A motor 8 for rotating the drum 10 and torque fluctuation detecting means for detecting torque fluctuation of the motor 8 are provided. The control device 5 determines the cycle of the damper 23 based on the cycle of torque fluctuation detected by the torque fluctuation detecting means. The typical control.
According to this, the phase of the unbalance can be accurately grasped based on the torque fluctuation, and the damping force of the damper 23 can be varied in accordance with the actual rotation cycle of the drum 10. Further, the torque fluctuation detecting means can be made relatively inexpensive and simple, for example, by using a current sensor 54 that detects the current flowing through the motor 8.

  The control device 5 executes periodic control of the damper 23 in a low speed region where primary resonance occurs in the water tank 6, that is, when the water tank 6 vibrates mainly in the left-right direction. When the high-speed region higher than the low-speed region, that is, when the water tank 6 vibrates mainly in the vertical direction, control for relatively increasing the damping force of the damper 23 is executed. According to this, since the vibration in the vertical direction of the water tank 6 increases in the high-speed region, the damping force of the damper 23 can be relatively increased accordingly, and the vibration suppressing effect can be enhanced. Therefore, unlike the configuration in which the control is changed when the vibration is increased based on the detection of the vibration of the water tank 6, the control according to the vibration mode of the water tank 6 is performed in both the low speed region and the high speed region. Can be suppressed in advance. Therefore, the gap between the water tank 6 and the outer box 1 can be set smaller than before, and the outer box 1 can be made compact or the capacity of the drum 10 can be increased.

Second Embodiment
FIGS. 10-11 (b) shows 2nd Embodiment, and it abbreviate | omits description by attaching | subjecting the same code | symbol to the same part as the already described part, and demonstrates a different point hereafter.

FIG. 10 shows the outputs of the vibration sensors 20a and 20b corresponding to two rotations when the laundry W is rotated clockwise with the position where the laundry W is unevenly distributed in the drum 10 as 0 degree. That is, the curve _{P 100} shown in FIG. 10, the vibration sensor 20a in the rotation speed (100 rpm) for less than the rotational speed of the drum 10 at the primary resonant shows an exaggerated output 20b, the torque fluctuation mentioned above It can be seen that the output P ₁₀₀ changes in the same cycle. However, as shown in FIG. 11 (a), when the rotational speed of the drum 10 is 100 rpm, the vibration sensor 20a, the output _{P 100} of 20b, rather than the torque fluctuation _{T 100} as described above, the change is small gentle curve Draw. Thus, the vibration sensor 20a, 20b, in primary resonance occurs before the rotational speed, since the smaller the change in the output P _100, there is a fear that the detection of the rotation period of the drum 10 becomes difficult.

On the other hand, a curve Pf shown in FIG. 10 indicates the outputs of the vibration sensors 20a and 20b at the time of primary resonance, and the phase is delayed by 90 degrees from the curve P ₁₀₀ (or torque fluctuation). Further, a curve P ₂₀₀ shows the outputs of the vibration sensors 20a and 20b at a rotation speed (200 rpm) exceeding the rotation speed of the drum 10 at the time of the primary resonance, and the phase is 180 from the curve P ₁₀₀ (or torque fluctuation). Be late. In this case, as shown in FIG. 11B, since the rotational speed of the drum 10 is relatively high, a change in the output P ₂₀₀ of the vibration sensors 20a and 20b also becomes obvious. Further, as shown in the figure, the rotational speed of the drum 10 if the 200 rpm, the variation of the torque variation _{P 200} is reduced.

When observing FIGS. 10 to 11B comprehensively, when the rotational speed of the drum 10 is 100 rpm, the torque fluctuation T ₁₀₀ is used to ensure the phase of unbalance based on the current detection signal from the current sensor 54. It can be seen that it can be detected. In addition, when the rotational speed of the drum 10 is 200 rpm, the output P ₂₀₀ of the vibration sensors 20a and 20b is shifted from the unbalanced phase by 180 degrees, but the rotational period of the drum 10 can be reliably detected.

  Accordingly, the ROM 51a stores a rotational speed (for example, a rotational speed when the outputs of the vibration sensors 20a and 20b are delayed by 180 degrees with respect to the phase) as an index for switching the means for detecting the rotational period. Let me. When the controller 5 determines that the rotational speed of the drum 10 has reached the rotational speed at which the delay of 180 degrees is generated based on the detection signal from the rotational sensor 53 in the rotational speed increasing step, the rotational period detecting means Is switched from the current sensor 54 to the vibration sensors 20a, 20b.

  When the rotational speed of the drum 10 is 200 rpm, the outputs of the vibration sensors 20a and 20b are delayed by 180 degrees from the unbalanced phase, but when the damper 23 is variably controlled at a cycle of 180 degrees as shown in FIG. The same periodic control as in the first embodiment can be performed without calculating the unbalanced phase based on the output.

  As described above, the control device 5 includes the current sensor 54 as the torque fluctuation detecting means and the vibration sensors 20a and 20b as the vibration detecting means as means for detecting the rotation period detecting means or the unbalanced phase. The sensor 54, 20a, 20b having a larger output change in relation to the rotation speed of the drum 10 is selectively used. This makes it possible to accurately detect the unbalanced phase regardless of changes in the rotational speed of the drum 10.

The “periodic variable control” is not limited to the above-described on / off control. That is, when the magnitude of the current flowing through the coil 41 is a large current I _L and a small current I _S (I _L > I _S ), control for repeating the energized state and the disconnected state in the low speed region (see FIG. 1). Alternatively, the may be performed a periodic control repeating the conductive state of a large current I _L and the small current I _S for each rotation of the drum 10.

Further, in the high speed region, control for making the damping force of the damper 23 relatively higher than that in the low speed region may be executed. Specifically, it executes the control in the low speed range repeated energization and deenergized state in the small current I _S, performing a control to repeat the energization and deenergized state with a large current I _L in the high speed region Thus, vibration and noise in the high speed region R2 can be suppressed.

In addition, in the suspensions 7a and 7b, the coils 41 are arranged in two upper and lower stages, but various changes are possible, for example, a single coil configuration.
As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  In the drawings, 1 is an outer box, 5 is a control means (rotation cycle detection means), 6 is a water tank, 7a and 7b are suspensions, 10 is a drum, 23 is a damper, and 20a and 20b are rotation cycle detection means (vibration detection means). , 54 indicates a rotation period detecting means (torque fluctuation detecting means).

Claims (4)

An outer box,
A water tank provided in the outer box;
A drum rotatably provided in the water tank;
A damper that is provided between the outer box and the water tank and attenuates the vibration of the water tank;
Control means for variably controlling the damping force of the damper,
Wherein, the drum, wherein said changing the damping force of the damper, performing periodically repeating controlled in accordance with the rotation of the drum about the variable control during the said drum rotation 1 in the dehydration step Type washing machine. A rotation period detecting means for detecting a rotation period of the drum;
The drum type washing machine according to claim 1, wherein the control means executes periodic control of the damper based on the rotation period detected by the rotation period detection means. The rotation period detection means includes a motor that rotates the drum and a torque fluctuation detection means that detects torque fluctuation of the motor.
The drum type washing machine according to claim 2, wherein the control means executes periodic control of the damper based on a period of torque fluctuation detected by the torque fluctuation detection means.   The control means performs periodic control on the damper in a low speed region where primary resonance occurs in the water tank, and relatively increases the damping force of the damper in a high speed region higher than the low speed region. The drum type washing machine according to any one of claims 1 to 3, wherein control to perform is performed.

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