KR20110022366A - Laundry machine - Google Patents

Abstract

PURPOSE: A washing machine is provided to compensate unbalance by controlling a location of ball balancer balls considering a specification of a vibration mode. CONSTITUTION: A control unit performs rotation of a drum at a predetermined speed in a first rotation speed section(c1). The control unit compares the sensed first unbalance with first permitted unbalance. The controller enters into an excessive area by the acceleration of the drum. In a third rotation speed, the controller performs rotation at a predetermined speed for a first set time(c2). The control unit exceeds the transient zone by acceleration over a third rotation speed(c3).

Description

Washing Machine {Laundry Machine}

The present invention relates to a laundry machine for processing laundry.

Generally, a washing machine includes a washing machine and a dryer. The washing machine includes a pulsator-type washing machine and a drum washing machine, and there is also a combined-use washing machine, which may not only perform washing but also drying.

A dryer is a laundry apparatus for drying wet laundry using hot air or the like.

In the drum washing machine, the tub is arranged horizontally, and the drum is also arranged horizontally therein. The laundry is placed inside the drum and tumbled and washed as the drum is pointed.

The tub serves to receive the wash water, and the drum is where the laundry is placed and washing is performed.

The drum is rotatably installed in the tub.

The drum has a rotating shaft connected to the rear, the rotating shaft receives a rotational force from the motor. Thus, the rotational force is transmitted to the drum through the rotation shaft by the rotation of the motor to rotate the drum.

During washing, as well as during rinsing and dehydration, the drum is rotated and the drum vibrates while rotating.

The rotating shaft penetrates the rear wall of the tub and protrudes out of the tub. In a conventional washing machine, a bearing housing is sometimes inserted into an insert molding on a rear wall of a tub. Alternatively, the bearing housing is fastened to the rear wall of the tub.

The rotating shaft is supported by the bearing housing, and the vibration of the drum is transmitted to the bearing housing and the tub through the rotating shaft.

Thus, the tub vibrates with the drum, and a shock absorbing member is connected to the tub to damp the vibration.

That is, the conventional washing machine is a structure in which the vibration of the drum is transmitted to the tub as it is, such a vibration is a structure that is supported through the buffer support member connected to the tub.

In the washing apparatus, when the drum is rotated beyond the transient area, a method of passing through the transient area is provided while reducing vibration of the drum.

The present invention provides a method of controlling the positions of the balls of the ball balancer in consideration of the characteristics of the vibration mode appearing in the transient region.

In one embodiment, a washing apparatus to which a control method according to the present invention is applied includes a drum, a front ball balancer having a plurality of front balls 32f and a front ball balancer mounted to a front of the drum, and a plurality of rear balls. It may include a rear ball balancer mounted on the rear portion of the.

In addition, an embodiment of the control method may include: a first constant speed rotation step of rotating the drum at a first rotational speed at a constant speed and detecting a first unbalance and comparing it with a first allowable unbalance; A second constant speed rotation step of detecting the drum at a second rotation speed greater than the first rotation speed and comparing the drum with a second allowable unbalance; A first transient region step of accelerating to enter the transient region; A third constant speed rotation step of performing a constant speed rotation for a first predetermined time at a third rotation speed at which the vertical displacement with respect to the rotation axis of the transient area is opposite to each other in the front and rear portions of the drum; And a second transient area step of escaping the transient area by accelerating above the third rotational speed.

In the washing apparatus, when the drum is rotated beyond the transient area, the drum can be effectively passed while reducing the vibration of the drum.

In particular, by controlling the positions of the balls of the ball balancer in consideration of the characteristics of the vibration mode appearing in the transient region, the amount of vibration can be effectively reduced because the unbalance is canceled to suit the situation of the vibration mode.

Moreover, the amount of vibration can be reduced in response to the vibration mode in which the drum and the rear part thereof are displaced in opposite directions with respect to the rotation axis, that is, the diagonal vibration mode.

Figure 1 shows a partially exploded perspective view of an embodiment of a washing machine of the present invention.

The tub is fixedly supported by the tub in the cabinet. The tub includes a tub front 100 constituting the front portion and a tubere 120 constituting the rear portion. The tub front 100 and the tubular 120 are assembled by screws, and form a space in which a drum is accommodated. The tubular 120 has an opening in the rear surface. The inner circumference of the rear of the tubular 120 is connected to the outer circumference of the rear gasket 250. The inner circumference of the rear gasket 250 is connected to the tub back 130. The tub back 130 has a through hole through which a rotating shaft passes. The rear gasket 250 is made of a flexible material so that the vibration of the tubback 130 is not transmitted to the tubular 120.

The tubular 120 has a rear surface 128. The rear surface 128, the tub back 130, and the rear gasket 250 of the tubular 120 constitute a rear wall surface of the tub. The rear gasket 250 is connected to the tub back 130 and the tubular 120 to be respectively sealed so that the wash water in the tub does not leak. The tubback 130 vibrates with the drum when the drum rotates, and is spaced apart from the tubular 120 at a sufficient interval so as not to interfere with the tubular 120. Since the rear gasket 250 is made of a flexible material, the tubback 130 allows relative movement without interfering with the tubular 120. The back gasket 250 may have a pleat 252 that may extend to a sufficient length to allow such relative movement of the tubback 130.

The front portion of the tub front 100 is connected to the foreign matter prevention member 200 for preventing foreign matter from flowing between the tub and the drum. The foreign matter pinching member 200 is made of a flexible material, it is fixed to the tub front (100). The foreign matter prevention member 200 may be made of the same material as the rear gasket 250. The foreign matter pinching member 200 is referred to as a front gasket for convenience.

The drum is composed of a drum front 300, a drum center 320, a drum bag 340 and the like. In addition, ball balancers 310 and 330 are installed at the front and rear portions of the drum, respectively. The drum bag 340 is connected to the spider 350, the spider 350 is connected to the rotating shaft 351. The drum is rotated in the tub by the rotational force transmitted through the rotating shaft 351.

The rotary shaft 351 is directly connected to the motor through the tub back 130. Specifically, the rotor of the motor and the rotation shaft 351 are directly connected. The bearing housing 400 is coupled to the rear surface of the tub bag 130. The bearing housing 400 rotatably supports the rotation shaft 351 between the motor and the tub back 130.

The stator is fixed to the bearing housing 400. Then, the rotor surrounds the stator. As described above, the rotor is directly connected to the rotation shaft 351. The motor is an outer rotor type motor that is directly connected to the rotating shaft 351.

The bearing housing 400 is supported from the cabinet base 600 through the suspension unit. The suspension unit includes three vertical supports and two inclined supports that are inclined with respect to the front and rear directions.

The suspension unit has a first cylinder spring 520, a second cylinder spring 510, a third cylinder spring 500, a first cylinder damper (symmetrically installed opposite the second cylinder damper and not shown in the drawing), It may include a second cylinder damper (530).

The first cylinder spring 520 is connected between the first suspension bracket 450 and the base 600. In addition, the second cylinder spring 510 is connected between the second suspension bracket 440 and the base 600.

The third cylinder spring 500 is directly connected between the bearing housing 400 and the base 600.

The first cylinder damper 540 is inclined between the first suspension bracket 450 and the base rear part, and the second cylinder damper 530 is inclined between the second suspension bracket 440 and the base rear part. It is installed.

The cylinder springs of the suspension unit may be connected to the cabinet base 600 to allow a certain degree of elastic deformation to allow the drum to move forward and backward and to the left and right in the right direction without being completely fixed. That is, it is elastically supported to allow some degree of rotation back and forth and to the left and right with respect to its support point connected to the base.

The vertical installation of the suspension can be configured to elastically dampen the vibration of the drum and the tilted installation can be configured to damp the vibration. That is, in the vibration system including the spring and the damping means, the vertical installation may serve as a spring and the tilted installation may serve as a damping means.

The tub front and the tubular are fixedly installed in the cabinet, and the vibration of the drum is buffered and supported by the suspension unit. Substantially, the support structure of the tub and the drum may be referred to as a separate form, and the tub does not vibrate even if the drum vibrates.

The bearing housing and the suspension brackets are connected by the first weight 431 and the second weight 430.

Hereinafter, the ball balancer will be described in more detail.

First, when the drum rotates while the laundry is placed in the drum, unbalance may occur due to the laundry. In particular, since the unbalance is a factor that increases the vibration of the drum in the dehydration process, it is desirable to reduce the unbalance (UB) as much as possible. In particular, as the rotational speed of the drum is increased to meet the natural frequency region of the washing machine, if the unbalance is large, the vibration amount is too large can be a problem.

It is important to reduce the unbalancer as much as possible, since it may be nearly impossible to distribute the laundry completely uniformly within the drum. In addition, it may be necessary to set an allowable unbalance amount for a certain washing machine in consideration of the characteristics of the washing machine. Thus, it is necessary to detect the unbalance and to control the rotation of the drum in comparison with the allowable unbalance.

There may be a number of ways to reduce unbalance, but also so-called podis dispersion or possum operations that cause the position of the laundry in the drum to vary.

It is also conceivable to offset the unbalance of the laundry by reducing the unbalance of the laundry so that the fluid is located opposite the position of the unbalance of the laundry in order to reduce the unbalance. In other words, it is conceivable to use a balancer.

In this embodiment, a ball balancer is used as such a balancer, and one each is used in the front and rear portions of the drum.

In this embodiment, as shown in Fig. 2, the front ball balancer 310 is mounted to the drum front portion, and the rear ball balancer 330 is mounted to the rear portion of the drum. Specifically, the front ball balancer 310 is mounted to the front portion of the drum front 300, the rear ball balancer 330 is mounted to the rear portion of the drum bag 340. For such mounting, the front portion of the drum front 300 may have a front mounting groove formed as a recess recessed to the rear, and the drum bag 340 is recessed forward to form a rear mounting groove. Can have

In this embodiment, the front ball balancer 310 and the rear ball balancer 330 are the same. However, the same ball balancer does not necessarily have to be mounted at the front and rear of the drum.

3 shows a cross-sectional structure of the front ball balancer 310.

First, the front ball balancer 310 is configured to include a race 31, the ball 32 and the oil (33). The race 31 may have a shape such as a ring having a ball receiving portion 31a which is an inner space in which the ball 32 may move. The cross-sectional shape of the ball receiving portion 31a may be approximately quadrangular as shown in the drawing.

A plurality of balls 32 are accommodated in the ball accommodating portion 31a. The number of balls 32 accommodated, the diameter of the balls 32, etc. are determined in consideration of the unbalance amount to be offset, but may consider the vibration characteristics of the washing machine.

In addition, the ball accommodating part 31a is filled with the oil 33. The amount and viscosity of the oil 33 being filled affect the movement of the ball 32, so it is preferable to consider this. The amount and viscosity of the oil 33 can be determined such that the ball 32 of the ball balance has the required movement. In addition, the vibration characteristics of the washing apparatus may be considered.

In this embodiment, 14 balls 32 are accommodated, the diameter of which is about 18.55 ~ 19.55mm, about 19.05mm. The racer has a cross-sectional area of 410 to 413 mm 2, which is about 412 mm 2, and a diameter of the center of the ball receiving part 31 a which is about 505 mm. In addition, the oil 33 is PDMS (poly dimethylsiloxane) is used as the silicone oil series. The oil 33 has a viscosity of 300cs at room temperature, the filling amount is about 350cc as 340 ~ 360cc. The present invention is not limited to the characteristic values of such a ball balancer.

Hereinafter, a method of using the movement of the ball in the ball balancer when the drum rotates with unbalance. Since the ball balancer is mounted on the drum and rotates together, the movement control of the ball in the ball balancer can be achieved through the rotation control of the drum.

In particular, when the rotational speed of the drum is close to the natural frequency of the washing machine, it is important that the ball is controlled at this time because the vibration of the drum can be intensified.

Conventional washing machines generally appear in the natural vibration mode at about 200 ~ 270rpm, this section is also referred to as the transient region. There may be a plurality of natural vibration modes in such a transient area, and when it is necessary to rotate the rotational speed of the drum beyond the transient area, it is important to control the vibration amount of the drum to be as small as possible.

The transient region may be generally defined as a range of rotational speed of the drum, and may be referred to as a region including natural frequencies as described above. The natural frequency in the vibration system is determined by mass and stiffness (for example, spring constant). In the washing machine, the mass may vary depending on the quantity of the washing machine.

As a method of reducing the vibration amount of the drum in the transient region, it is conceivable to reduce the unbalance amount. For this purpose, before entering the transition zone, the laundry is evenly distributed to distribute the laundry in the drum as evenly as possible.

In the case of using a ball balancer, it is conceivable to quickly pass the transient area while the positions of the balls are located on the opposite side of the unbalance of the laundry. At this time, the positions of the balls in the middle of the transition region is preferably located at the opposite position of the unbalance. Here, the relationship between the positions of the balls and the unbalanced position may be defined as the angle of the centrifugal force center of the balls with respect to the centrifugal force center of the unbalance (hereinafter, referred to as a 'central force center angle'). Alternatively, the relationship between the positions of the balls and the unbalanced position may be defined as an angle formed by the ball which is located nearest to the unbalanced centrifugal force center (hereinafter, referred to as the 'closest ball angle').

4 shows the positional relationship between the unbalanced UB and the balls. In Fig. 4, the positional relationship between the balls and the unbalance is the nearest ball angle θ1 and the centrifugal force center angle θ2. For convenience, the angle between the ball and the unbalance is assumed to mean θ1 or θ2.

The ball may be a steel ball, if its size is constant and if they are all attached side by side, the centrifugal force center is P1 as shown in FIG.

The balls are rotated by the frictional force as the drum is rotated. The balls rotate at a different speed than the drum because they are not constrained to the drum for its rotational movement. However, unbalance is laundry that is in close contact with the drum inner wall and can rotate at almost the same speed as the drum due to sufficient friction and lift of the drum inner wall. Thus, the rotational speed of the unbalanced and the rotational speed of the balls are different. Since the balls rotate by the rotation of the drum, the rotation speed of the unbalance becomes faster than the rotation speed of the balls. Precisely, the rotational angular velocity is fast.

As the rotational speed of the drum becomes faster and faster, the balls are brought into close contact with the outer circumferential surface of the ball receiving portion of the racer by the centrifugal force. When the centrifugal force is increased and the frictional force between the circumferential surface and the balls exceeds a certain value, the balls rotate like a drum. Will rotate with speed. In this case, the balls have a constant position with respect to the drum as well as unbalance. In the present specification, the case where the balls are rotated with a predetermined position on the drum as described above is referred to as a 'ball balancing position' or 'ball balanced'.

As described above, the lowest rotational speed among the ball balancing rotational speeds may vary depending on the ball balancer. In addition, the ball balancer may be different from the vertical installation and the horizontal installation. This is because, in the case of vertical installation, the contact of the ball with the outer circumferential surface of the ball receiving portion of the race under the influence of gravity may vary depending on the position. If the constant speed is maintained for a certain time at the rotational speed at which the ball can be balanced, the balls may be positioned in the opposite position to the unbalanced position. 4, it can be referred to as the position of P2.

On the other hand, at a rotational speed below the transient region, the centrifugal force may be low to prevent ball balancing. Thus, when passing through the transient area, the ball may be positioned on the opposite side of the unbalance during the passing of the transient area by grasping the positions of the balls while performing a constant speed rotation rather than passing the ball after performing the balancing. That is, even if the ball is not balanced, it is possible to control the ball to pass through the transient area while located on the opposite side of the unbalance. For example, referring to FIG. 4, it may be controlled to pass through the transient area while the angle θ1 or θ2 between the ball and the unbalance is 90 degrees or more. In this case, it may be more preferable if the angle is 180 degrees in the middle of the transient region.

At this time, when the constant speed rotation in the transient region or less as described above, the vibration of the drum may be in the same direction the displacement of the front and rear parts. Thus, as shown in FIG. 5, the angle θ3 formed by the front balls 32f and the rear balls 32e may be within 90 degrees. For reference, FIG. 5 is a diagram schematically illustrating a positional relationship between the front balls 32f and the rear balls 32e when viewed from the front as a drum.

By the way, there may be a vibration mode in which the vibration of the drum in the transient region is the displacement of the front and rear portions in the opposite direction. For convenience, such a vibration mode is called a diagonal vibration mode. In this diagonal vibration mode, if the front balls 32f and the rear balls 32e maintain the angle within 90 degrees as described above, the unbalance for the diagonal vibration mode may not be offset properly. The vibration of the drum may be intensified.

As described above, the diagonal vibration mode may start to appear as the natural frequency of the natural vibration mode vibrating in the diagonal vibration mode approaches.

Therefore, it may be advantageous to modify the position of the front balls 32f and the rear balls 32e before it reaches its natural frequency in the diagonal vibration mode to reduce vibration.

To this end, the drum is rotated at a constant speed for a predetermined time at a rotational speed at which the diagonal vibration mode appears before the natural frequency, so that the positions of the front balls 32f and the rear balls 32e are advantageous to offset the unbalance. It is desirable to.

In particular, the washing apparatus of the present embodiment as described above has a completely different structure from the conventional one, and since the natural vibration mode of the diagonal vibration mode as described above may occur in the transient area, it is not necessary to correct the positions of the balls as described above. desirable.

Hereinafter, a control method of passing through the transient region in order to perform dehydration in the above washing machine will be described with reference to the rotational speed graph of the drum with time with reference to FIG. 6. In FIG. 6, section a is the first constant rotation stage, section b is the second constant rotation stage, section c1 is the first transient region stage, section c2 is the third constant rotation stage, c3 is the second transient region stage, and d is the first 4 Indicates constant speed rotation stage.

First, in a section, poling or inflation is performed, and the first unbalance is sensed while rotating at a first rotational speed and compared with the first allowable unbalance.

At this time, if the detected first unbalance is less than the first allowable unbalance, the controller accelerates to the second rotation speed and rotates at a constant speed (section b). In section b, the second unbalance is detected and compared with the second allowable unbalance. If the detected second unbalance is less than or equal to the second allowable unbalance, preparation is made to pass section c, which is a transient region.

Here, as shown in A of FIG. 6, in the c1 of the transient region section, the vibration mode of the drum is a section in which the natural vibration mode in which the front part and the rear part are displaced in the same direction. As shown in B of FIG. 6, section c3 is a section in which the front and rear displacements of the drum are opposite to each other, that is, the natural vibration mode vibrates in the diagonal vibration mode.

First, in order to pass the section c1, while determining the position of the ball while making a constant rotation in section b, the acceleration time point t1 is determined. It is possible to determine t1 and its acceleration slope so that the unbalance and the angle of the ball in the c1 section are greater than 90 degrees. At this time, t1 and the acceleration gradient may be determined such that the unbalance and the ball angle are 180 degrees in the middle of the c1 section. In the c1 section, the centrifugal force center of the front balls 32f and the centrifugal force center of the rear balls 32e may form an angle within 90 degrees based on the rotation center of the drum when viewed from the front. The front balls 32f and the rear balls 32e are preferably at an angle within 90 degrees to reduce the amount of vibration in the vibration mode in which the front and rear portions of the drum are displaced in the same vertical direction with respect to the rotation axis.

When the third rotational speed is reached through the c1 section, the constant speed rotation is performed for a predetermined time (section c2). In section c2, the section is prepared to pass the natural vibration mode of diagonal vibration shown in c3. In the c2 section, the drum may vibrate in the diagonal vibration mode as the drum rotates at a rotational speed close to the natural frequency of the natural vibration mode of the diagonal vibration. At this time, as the constant speed is maintained for a predetermined time, the positions of the balls of the front ball balancer and the rear ball balancer are changed according to the vibration mode as described above.

As it passes through the section c2, the angles of the front balls 32f and the front unbalance and the angles of the rear balls 32e and the rear unbalance in the c3 section pass through the transient region, respectively. At this time, when looking at the drum from the front, the angle between the front balls 32f and the rear balls 32e may be 90 degrees or more. In order to reduce the amount of vibration in the diagonal vibration mode, the angle between the front balls 32f and the rear balls 32e is preferably 90 degrees or more.

In this case, the third rotational speed and the set time may be determined in consideration of the balance between the front ball balancer and the rear ball balancer. That is, as the drum is rotated during the set time at the third rotational speed, the front balls 32f and the rear balls 32e form an angle of 180 degrees with the front unbalance and the rear unbalance, respectively, to offset the unbalance. After moving to a position, it may be determined to remain at that position.

In the present embodiment, the third rotational speed is preferably in the range of 250 to 290 rpm. If the rotation speed is too low, the vibration in the diagonal vibration mode is weak, so the c2 section may be long or not effective.If the rotation speed is too high, the vibration may be severe and the ball may become unstable and the position of the ball may not change properly. have. Preferably it is set to 270 rpm. The c2 section is preferably maintained at about 30 seconds.

After passing through section c3 where the natural vibration mode of the diagonal vibration is displayed, the transient region is escaped, and after that, the drum is rotated at a high speed to perform dehydration in earnest. At this time, it is necessary to change the position of the balls before entering such a dehydration step.

In the section c2, the front balls 32f and the rear balls 32e are positioned to offset the unbalance for the diagonal vibration, and thus may not be suitable in the main dehydration step in which the vibration mode may be different.

Therefore, it is preferable to have a section d for repositioning the ball while performing a constant speed rotation at the fourth rotational speed after passing through the transient region. That is, it is desirable to reposition the balls so as to be suitable for offsetting the unbalance for the vibration mode of the main dehydration step.

In the dehydration step, the balls may flow to deepen the unbalance, so it is preferable to allow the ball to be balanced in the section d. That is, it is preferable to keep the ball in a position where it can offset the unbalance at the fourth rotational speed, preferably in the vibration mode.

The fourth rotational speed is preferably determined as the rotational speed at which the diagonal vibration mode does not appear. For example, it is preferable to determine the rotational speed that is somewhat different from the natural frequency of the natural vibration mode of the diagonal vibration so that the influence of the diagonal vibration mode is not affected.

The section d may be set to about 60 seconds as 50 to 70 seconds at 380 rpm as 370 to 390 rpm.

On the other hand, the acceleration slope in the c1 section is preferably smaller than the acceleration slope in the c3 section. When the ball is balanced at the third rotational speed, the balls may move relatively fast because the balls may be almost unmovable, but in the c1 zone, the balls continue to move unbalanced and pass the c1 zone in consideration of such movement. This is because it determines the speed at which

Finally, after passing section d, dehydration may be performed in earnest by performing a dehydration step of about 1000 rpm or more.

In this embodiment, the dehydration is carried out as an example, but if there is a case in which the drum is rotated beyond the transient region in addition to dehydration, it may be applied thereto.

1 shows an embodiment of a washing apparatus according to the present invention.

2 is a partial cross-sectional view of the washing apparatus of FIG.

3 shows a cross section of the front ball balancer.

4 shows the relationship between mass and natural frequency.

5 shows the unbalance and the positional relationship of balls according to drum rotation.

Figure 6 shows one embodiment of a dehydration method according to the present invention.

Description of the main parts of the drawing

100: tub front 120: turbine

130: tub bag 200: front gasket

250: rear gasket 300: drumfront

310: front ball balancer 320: drum center

330: rear ball balancer 340: drum back

350: spider 351: rotary shaft

400: Bearing housing 430, 431: Weight

440, 450: Suspension bracket 500, 510, 520: Cylinder spring

530: cylinder damper 600: base

620: cabinet rare 630: cabinet light

640: cabinet left

Claims (19)

In the control method of the laundry machine comprising a drum, a front ball balancer having a plurality of front balls mounted on the front of the drum, and a rear ball balancer having a plurality of rear balls mounted on the rear of the drum, A first constant speed rotating step of rotating the drum at a first speed at a constant speed and detecting a first unbalance and comparing it with a first allowable unbalance; A first transient region step of accelerating to enter the transient region; A third constant speed rotation step of performing a constant speed rotation for a first predetermined time at a third rotation speed at which the vertical displacement with respect to the rotation axis of the transient area is opposite to each other in the front and rear portions of the drum; A second transition region step escaping the transient region by accelerating above the third rotation speed; Control method of the washing apparatus comprising a. The control of the washing apparatus as set forth in claim 1, wherein the second transient area step includes a rotation speed in which a natural vibration mode in which the vertical displacement with respect to the rotation axis of the drum is opposite to the front part and the rear part is shown. Way. 3. The method of claim 2, wherein the first predetermined time of the third constant rotation step is that the front balls make an angle of 90 degrees or more with the front unbalance of the drum, and the rear balls make an angle of 90 degrees or more with the rear side unbalance of the drum. Method for controlling the washing machine, characterized in that determined to achieve. The center of the centrifugal force of the front balls forms an angle of 180 degrees with the front side unbalance, and the centrifugal force centers of the rear balls have an angle of 180 degrees with the rear side unbalance. Method for controlling the washing machine, characterized in that determined to achieve an angle. The method of claim 4, wherein the first predetermined time of the third constant speed rotation step is such that the centrifugal force center of the front balls and the angle of the front unbalance and the centrifugal force center of the rear balls and the angle of the rear unbalance are respectively constant. The control method of the laundry machine, characterized in that determined to be maintained. The method of claim 3, wherein the centrifugal force center of the front balls and the centrifugal force center of the rear balls in the second transition region step are 90 degrees or more when viewed from the front. The control method according to any one of claims 3 to 6, wherein the third rotation speed of the third constant speed rotation step is between 250 and 290 rpm. The control method according to claim 7, wherein the third rotation speed of the third constant speed rotation step is 270 rpm. The control method according to any one of claims 3 to 6, wherein the third rotation speed is a rotation speed at which the front ball balancer and the rear ball balancer can be ball balanced. 10. The method of claim 9, wherein the second transition region step has a larger acceleration slope than the first transition region step. The control method according to claim 9, further comprising a fourth constant speed rotation step of performing a constant speed rotation for a second predetermined time at a fourth rotation speed after the second transient area step. 12. The method according to claim 11, wherein the fourth rotational speed is a rotational speed at which the drum vibrates so that the vertical displacement with respect to the rotational axis is in the same direction as the front part and the rear part. 4. The control method according to claim 3, wherein the first transient region step includes a rotation speed at which a natural vibration mode in which the vertical displacement with respect to the rotation axis of the drum is in the same direction as the front part and the rear part is shown. . The method of claim 13, wherein the centrifugal force center of the front balls and the centrifugal force center of the rear balls in the first transition region step when forming the angle of less than 90 degrees relative to the center of rotation of the drum when viewed from the front. Method of controlling the washing machine. The control method according to claim 1, further comprising a second constant speed rotating step of detecting a second unbalance at a second rotation speed greater than the first rotation speed and comparing the drum with a second allowable unbalance. In the control method of the laundry machine comprising a drum, a front ball balancer having a plurality of front balls mounted on the front of the drum, and a rear ball balancer having a plurality of rear balls mounted on the rear of the drum, A first transition region step in which a vertical displacement with respect to the rotation axis of the drum passes through a rotational speed in which a natural vibration mode in which the front part and the rear part are in the same direction; A constant speed rotation step of performing a constant speed rotation for a predetermined time after the first transient region step; A second transition region step in which a vertical displacement with respect to the rotation axis of the drum passes through a rotation speed in which a natural vibration mode in which the front part and the rear part are opposite to each other occurs; Method of controlling the washing apparatus comprising a. The method of claim 1 or 16, wherein the laundry machine: cabinet; A tub fixed to the cabinet; A drive unit including a rotating shaft connected to the drum, a bearing housing rotatably supporting the rotating shaft, and a motor connected to the rotating shaft; A connection member for flexibly connecting the driving unit and the rear opening of the rear of the tub; A suspension unit connected to the driving unit for buffer support; Washing apparatus control method comprising a. 17. The method according to claim 16, wherein the front balancer and the rear balancer, respectively, the number of the ball is 14, the diameter of the ball is 18.55 ~ 19.55mm, the ball receiving portion of the racer is a space in which the ball is accommodated 410 ~ 413mm2, The control method of the laundry machine, characterized in that the diameter of the center of the ball receiving portion cross-sectional area is 500 ~ 510mm. 17. The method of claim 16, wherein the front balancer and the rear balancer are respectively injected with 340-360 cc of oil having a viscosity of 300 cs in the ball receptacle.

Images