KR102343899B1 - Laundry treating machine - Google Patents

Abstract

Laundry treatment apparatus according to an embodiment of the present invention, a cabinet; a drum accommodated inside the cabinet; a tub for accommodating the drum; and a dynamic absorber provided to absorb vibrations of the cabinet, wherein the dynamic absorber includes: a support plate coupled to the cabinet; a mass movably placed on the support plate to absorb vibration transmitted to the cabinet; and a supporter disposed between the mass body and the support plate to support the mass body, wherein the supporter is in line contact or point contact with the bottom surface of the mass body so that the mass body has a low damping ratio.

Description

Laundry treating machine {Laundry treating machine}

The present invention relates to a laundry treatment device.

In the case of home appliances having a rotating drum inside, such as a washing machine or dryer, as the rotational speed (rpm) of the drum increases, the laundry put into the drum, that is, the horizontal excitation force is generated by the eccentricity of the load. do.

In particular, as in the spin-drying process, in the process of increasing the rotational speed of the drum, a transient vibration in which the horizontal vibration displacement of the washing machine cabinet rapidly increases at the resonant frequency point of the washing machine cabinet occurs. And, when the drum is constantly maintained at the maximum speed, a normal vibration in which the same vibration is constantly repeated occurs.

Due to such excessive vibration, the washing machine staggers in the left and right directions while the rotation speed of the drum increases. In addition, such excessive vibration appears more conspicuously in a stack type washing machine in which the washing machine is spaced apart from the ground.

For example, in the case of a small washing machine or a stack type washing machine stacked on the upper surface of an object for storing laundry, the vibration displacement of the excessive vibration is greater than that of a general washing machine placed directly on the installation surface, and the excessive vibration occurs during low-speed operation. That is, in the stack-type washing machine, the generation time of excessive vibration is earlier than in the washing machine placed directly on the floor.

In order to absorb such excessive vibration, a dynamic absorber is generally installed in the washing machine.

The dynamic absorber is a dynamic absorber using the principle of absorbing the vibration of the washing machine by vibrating in the horizontal direction with a phase 180 degrees opposite to the phase of the horizontal excitation force generated by the rotation of the drum.

In detail, when the drum rotates accelerated, as described above, an excitation force is generated in the horizontal direction by the rotation of the eccentric load (laundry). And, when the resonant frequency of the drum is reached while the rotational speed of the drum is increased, the washing machine cabinet performs harmonic vibration with a phase difference of 90 degrees from the excitation force at the resonance point.

In addition, at the resonance point, the dynamic absorber vibrates harmoniously with a phase difference of 90 degrees from the vibration of the washing machine cabinet. As a result, the vibration is canceled by vibrating in opposite directions with a 180 degree phase difference between the excitation force and the dynamic absorber, and as a result, the washing machine cabinet does not move.

The following US registered patent discloses a technology in which the dynamic absorber is provided in a washing machine.

The dynamic absorber disclosed in the prior art has a structure in which a frame is provided on a bottom surface of a casing of a washing machine, a viscoelastic member is placed on an upper surface of the frame, and a mass for absorbing vibration is placed on the upper surface of the viscoelastic member.

Such a dynamic absorber structure has the following problems.

First, since the viscoelastic member is placed on the bottom surface of the mass body, the load of the mass may continuously act on the elastic member, which may lead to damage and deterioration of the elastic member.

Second, when the mass vibrates in the horizontal direction, since the viscoelastic member absorbs the vibration by using a shear stress acting in the left and right directions, there is a disadvantage in that the excessive vibration cannot be effectively absorbed due to the low damping ratio.

Although it is described in the patent specification of the prior art that vibration can be effectively absorbed in the entire region of the rotation speed of the drum, the dynamic absorber disclosed in the prior art may have an effect of absorbing continuous oscillation. The ability to absorb transient vibrations in which the vibrational displacement suddenly increases is significantly reduced.

Third, since the shear stress alternately acts on the viscoelastic member, there is a disadvantage in that the possibility of damage to the viscoelastic member is increased and the lifespan is shortened.

Fourth, when the horizontal vibration acts on the washing machine to horizontally move the mass in the opposite direction to the vibration, the upper end of the elastic member moves in the horizontal direction and the elastic member is bent. As a result, there is a problem in that the mass body cannot swing in the left and right directions while maintaining a horizontal state for absorbing vibration. In other words, when the mass body swings in the left and right directions to absorb the lateral vibration, the left and right ends of the mass body are inclined downward due to the bending phenomenon of the elastic member. As a result, the horizontal vibration acting on the washing machine cannot be effectively absorbed.

US Registered Patent No. US8443636 (May 21, 2013)

The present invention has been proposed to improve the above problems.

Laundry treatment apparatus according to an embodiment of the present invention for achieving the above object, the cabinet; a drum accommodated inside the cabinet; a tub for accommodating the drum; and a dynamic absorber provided to absorb vibrations of the cabinet, wherein the dynamic absorber includes: a support plate coupled to the cabinet; a mass movably placed on the support plate to absorb vibration transmitted to the cabinet; and a supporter placed between the mass body and the support plate to support the mass body, wherein the supporter includes a roller in line contact with the bottom surface of the mass body so that the mass body has a low damping ratio, and the center of the roller a guide roller including a penetrating roller shaft; and a roller support part mounted on the support plate and supporting the roller shaft, wherein the roller support part includes a seating plate fixed to an upper surface of the support plate, and protruding from the upper surface of the seating plate, and inserted into the mass body It includes a plurality of guide bosses, and an accommodation hole for accommodating the guide rollers.
In addition, the laundry treatment apparatus according to an embodiment of the present invention, the cabinet; a drum accommodated inside the cabinet; a tub for accommodating the drum; and a dynamic absorber provided to absorb vibrations of the cabinet, wherein the dynamic absorber includes: a support plate coupled to the cabinet; a mass movably placed on the support plate to absorb vibration transmitted to the cabinet; a supporter disposed between the mass body and the support plate, the supporter being in line or point contact with the mass body so that the mass body has a low damping ratio; and one or a plurality of elastic dampers respectively disposed at both side ends of the mass in a movement direction of the mass, wherein the elastic dampers include a side support part in close contact with a side surface of the mass body, and horizontally from the side support part and a bottom support part extending to support a bottom surface of the mass body.
In addition, the laundry treatment apparatus according to an embodiment of the present invention, the cabinet; a drum accommodated inside the cabinet; a tub for accommodating the drum; and a dynamic absorber provided to absorb vibrations of the cabinet, wherein the dynamic absorber includes: a support plate coupled to the cabinet; a mass movably placed on the support plate to absorb vibration transmitted to the cabinet; a supporter placed between the mass body and the support plate to support the mass body in line or point contact with a bottom surface of the mass body; an additional mass placed on the support plate and spaced apart from the mass body in a direction crossing the movement direction of the mass body; and a slider disposed between the additional mass and the support plate and having damping due to frictional force.

According to the laundry treatment apparatus according to the embodiment of the present invention having the configuration as described above, the following effects are obtained.

First, since the dynamic absorber according to the embodiment of the present invention is provided in the laundry treatment apparatus, it is possible to effectively absorb various types of vibrations generated in the cabinet of the laundry treatment apparatus. In other words, by providing a mass for absorbing the transient vibration and a mass for absorbing the normal vibration, respectively, it is possible to absorb not only the transient vibration occurring in the low frequency (low rotation) region but also the normal vibration occurring in the high frequency (high rotation) region together. There are advantages that can be

Second, the dynamic absorber is designed so that the latter part of the vibration that absorbs the transient vibration and the early part of the vibration that absorbs the normal vibration overlap, so that the mass that absorbs the normal vibration partially contributes to absorbing the transient vibration, thereby absorbing the transient vibration. There is an advantage of increasing the amplitude.

In other words, there is an advantage in that the vibration displacement of the second transient vibration appearing in the latter part of the two secondary transient vibrations having a small vibration displacement occurring after absorption of the transient vibration is reduced.

Third, by overlapping the second half of the absorption region of the transient vibration and the first half of the absorption region of the normal vibration, the vibration displacement of the secondary transient vibration is significantly lowered. there is

1 is a perspective view of a laundry treatment apparatus according to an embodiment of the present invention;
2 is an exploded perspective view of the laundry treatment apparatus having a dynamic absorber according to an embodiment of the present invention;
3 is a perspective view of a dynamic reducer according to an embodiment of the present invention;
4 is an exploded perspective view of the dynamic absorber;
5 is a perspective view of a support plate constituting a dynamic reducer according to an embodiment of the present invention;
6 is a plan view of the support plate;
Fig. 7 is a longitudinal cross-sectional view taken along line 7-7 of Fig. 6;
8 is a plan view of a first mass according to an embodiment of the present invention;
9 is a perspective view of the first mass body;
10 is a view showing a buffer structure against vertical vibration of a first mass according to an embodiment of the present invention.
Fig. 11 is a longitudinal cross-sectional view taken along line 11-11 of Fig. 10;
12 is a cross-sectional view illustrating a separation preventing structure for preventing a mass from being separated from a support plate during a transport process of the laundry treatment apparatus;
13 is a perspective view of a second mass according to an embodiment of the present invention;
14 is a plan perspective view of a supporter according to an embodiment of the present invention;
15 is a bottom perspective view of the supporter.
16 is an exploded perspective view of the supporter;
Fig. 17 is a longitudinal cross-sectional view taken along line 17-17 of Fig. 14;
18 is a plan perspective view of an upper slider constituting a slider according to an embodiment of the present invention;
19 is a bottom perspective view of the upper slider.
Fig. 20 is a plan perspective view of a lower slider constituting the slider;
Fig. 21 is a bottom perspective view of the lower slider;
Fig. 22 is a longitudinal cross-sectional view taken along line 22-22 of Fig. 3;
23 is a plan perspective view of a second elastic damper according to an embodiment of the present invention;
24 is a bottom perspective view of the second elastic damper;
25 is a plan perspective view of a first elastic damper according to an embodiment of the present invention;
26 is a bottom perspective view of the first elastic damper;
Fig. 27 is a longitudinal cross-sectional view taken along lines 27-27 of Fig. 25;
28 is a graph showing the vibration displacement of a laundry treatment apparatus equipped with a dynamic damper including only a mass for absorbing excessive vibration;
29 is a graph showing the vibration displacement of a laundry treatment apparatus equipped with a dynamic absorber according to an embodiment of the present invention.

Hereinafter, a laundry treatment apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

First, the terms described in the present invention are defined.

Damped oscillation (vibration) or transient oscillation (vibration), which will be described below, is a vibration in which the vibration displacement of the cabinet rapidly increases at the resonance point of the drum when the drum in which laundry is loaded rotates acceleratingly for rinsing or dehydration. is defined as meaning

And, the steady-state oscillation (vibration) or continuous oscillation (vibration) described below is defined as meaning a vibration that occurs continuously with a nearly constant vibration displacement while the drum is maintained at the maximum speed. do.

And, that the dynamic absorber according to an embodiment of the present invention improves or absorbs the transient or normal vibration means that the dynamic absorber eliminates or minimizes the vibration displacement of the transient or normal vibration, thereby minimizing the vibration of the cabinet. can be understood as

1 is a perspective view of a laundry treatment apparatus according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the laundry treatment apparatus having a dynamic absorber according to an embodiment of the present invention.

1 and 2, in the embodiment of the present invention, the turbidity treatment apparatus 10 includes a cabinet 11 and a dynamic absorber ( 20), and a drum (not shown) accommodated in the cabinet 11 and a tub 16 for accommodating the drum.

In detail, the cabinet includes a front cabinet 111 , a side cabinet 112 , and a rear cabinet 113 . A top plate 12 is placed on the upper surface of the cabinet to cover the upper surface opening of the cabinet 11 .

In addition, a door 15 is rotatably coupled to the front cabinet 111 to put laundry into the drum. In addition, a detergent box 14 and a control panel 13 may be provided at an upper end of the front cabinet 111 .

In addition, the laundry treatment apparatus 10 may be placed directly on the installation surface, or may be placed on a separate stack W having a predetermined height h. The separate stack (W) may be an independent laundry device having a small volume, or may be a storage box for storing items including laundry, but is not limited thereto.

Meanwhile, the dynamic absorber 20 according to the embodiment of the present invention is seated on the upper surface of the cabinet 11 and is covered by the top plate 12 to block external exposure.

In addition, left and right ends of the dynamic absorber 20 are seated on the upper ends of the left and right side cabinets 112 . In addition, since the detergent box 14 and the control panel 13 are located on the inner upper side of the cabinet 11 , the dynamic absorber 20 is installed at the front end of the cabinet 11 to avoid interference with them. It may be located rearwardly spaced apart from the part.

For example, the horizontal distance between the front end of the support plate 24 and the front cabinet 111 may be set longer than the horizontal distance between the rear end of the support plate 24 and the rear cabinet 113 . have. However, the present invention is not necessarily limited thereto, and the dynamic absorber 20 may be located at the center of the upper surface of the cabinet 11 .

Hereinafter, the structure and function of the dynamic absorber 20 will be described in more detail with reference to the drawings.

3 is a perspective view of a dynamic reducer according to an embodiment of the present invention, and FIG. 4 is an exploded perspective view of the dynamic reducer.

3 and 4 , the dynamic reducer 20 according to the embodiment of the present invention includes a support plate 21 and a moving mass 22 slidably placed on the support plate 21 . and an elastic damper 25 provided on a side surface of the mass body 22 , and a sliding guide member supporting a bottom surface of the mass body 22 .

In detail, the mass 22 is slidably placed on the support plate 21 in a horizontal direction, specifically, in a left-right direction of the laundry treatment apparatus 10 . In addition, the mass body 22 may include a first mass body 23 and a second mass body 24 disposed behind the first mass body 23 . Here, it should be noted that the front mass may be defined as the first mass, and the rear mass may be defined as the first mass.

In addition, one of the first and second masses 23 and 24 is a damper for absorbing excessive vibration of the cabinet 11 , and the other is a damper for absorbing normal vibration of the cabinet 11 . . In addition, the damper for absorbing the excessive vibration may be placed in front of the damper for absorbing the normal vibration or may be placed behind the damper for absorbing the normal vibration.

In the present embodiment, the first mass body 23 at the front side is a damper for normal vibration reduction, and the second mass body 23 on the rear side is a damper for excessive vibration reduction. In addition, the mass of the damper for reducing the normal vibration may be formed to be larger than the mass of the damper for reducing the excessive vibration. The reason is that the normal vibration occurs at a high-speed rotation, and the transient vibration occurs at a relatively low-speed rotation than the normal vibration.

In addition, the elastic damper 25 includes a first elastic damper 25 supporting both sides of the first mass 23 and a second elastic damper supporting both sides of the second mass 24 ( 27) may be included. The elastic damper 25 is made of a material having predetermined elasticity and attenuation, and absorbs an impact generated when the mass body 22 moves in a left and right direction in a phase opposite to the excitation force of the drum. That is, the elastic damper 25 prevents the mass body 22 from directly hitting the side surface of the support plate 21 and, at the same time, functions to push the mass body 25 in the opposite direction by elastic force. .

Meanwhile, the sliding guide member includes a supporter 28 and a slider 29 .

In detail, the supporter 28 is disposed on the lower surface of the damper for normal vibration reduction, and the slider 29 is disposed on the lower surface of the damper for excessive vibration. Accordingly, in the present embodiment, the supporter 28 may be disposed below the first mass 23 , and the slider 29 may be disposed below the second mass 24 . Here, in order to improve the normal vibration, it is advantageous as the attenuation of the mass is small, and in order to improve the transient vibration, it is advantageous as the attenuation of the mass is large. Therefore, the damping of the supporter 28 is designed to be minimal, and the damping of the slider 29 is designed to be significantly larger than the damping of the supporter 28, but the resonance frequency at which excessive vibration occurs and the second mass 24 ), it is recommended to select it appropriately in consideration of the mass, etc.

Hereinafter, each component constituting the dynamic absorber 20 will be described in detail with reference to the drawings.

5 is a perspective view of a support plate constituting a dynamic reducer according to an embodiment of the present invention, FIG. 6 is a plan view of the support plate, and FIG. 7 is a longitudinal sectional view taken along lines 7-7 of FIG. 6 .

5 to 7 , the support plate 21 constituting the dynamic reducer 20 according to the embodiment of the present invention is a support member for supporting the mass 22, and the mass 22 is left and right. slidably movable in the direction.

In detail, the support plate 21 includes a plate body 211 made of a rectangular metal plate, a boundary wall 212 surrounding an outer edge of the plate body 211 in a substantially rectangular shape, and the A partition wall 213 extending a predetermined length from the inside of the outer wall 212 in the left and right direction, and a cabinet coupling part 215 extending from the outer edge of the outer wall 212 and seated on the upper surface of the side cabinet 112 . ) may be included.

In more detail, the outer wall 212 and the partition wall 213 protrude upward by a predetermined height from the upper surface of the plate body 211 by a forming process, thereby reinforcing the rigidity of the support plate 21 . In addition, a mass body accommodating part 214 in which the mass 22 is accommodated is formed inside the outer wall 212 . The protrusion height of the outer wall 212 and the partition wall 213 may be in the range of 1 mm to 15 mm. However, the present invention is not limited thereto, and at least the thickness of the mass body 22 is sufficient.

In addition, the partition wall 213 divides the mass body accommodating part 214 into a front first accommodating part 214a and a rear second accommodating part 214b. Left and right ends of the partition wall 213 may extend to the inner edge of the outer wall 212 , and as shown, both ends may be spaced apart from the inner edge of the outer wall 212 by a predetermined distance. can

And, in the present embodiment, since the mass (or weight) of the first mass body 23 is greater than that of the second mass body 24 , the partition wall 213 is later than the front end of the outer wall 212 . It may be located closer to the end.

Meanwhile, a plurality of cabinet coupling parts 215 may be formed on each of the left and right edges of the plate body 211 . In addition, one or a plurality of fastening holes 215a may be formed in each cabinet coupling part 215 . A fastening member such as a screw passes through the fastening hole 215a and is inserted into the upper surface of the side cabinet 112 .

In addition, an avoiding groove 215b may be formed between the cabinet coupling portions 215 adjacent in the front-rear direction. Since the avoiding groove 215b is formed, it is possible to prevent an obstacle such as a ground wire or bolt head coupled to the upper surface of the side cabinet 112 from interfering with the support plate 21 .

In addition, a plurality of strength reinforcing portions 217 are formed in the portion of the plate body 211 corresponding to the mass body accommodating portion 214 , and the plurality of strength reinforcing portions 217 are formed by a forming process. It may be formed with a hammer having a predetermined depth downward from the bottom surface of the body 211 . In addition, the plurality of strength reinforcement portions 217 may be spaced apart from each other by a predetermined distance in the front-rear direction.

In detail, the plurality of strength reinforcing units 217 includes a plurality of first forming units 217a (or first strength reinforcing units) formed in the first receiving unit 214a region, and the second receiving unit ( 214b) may include a plurality of second forming portions 217b (or second strength reinforcing portions) formed in the region.

In addition, the left and right edges of the plurality of first forming parts 217a are connected to the inner edges of the outer wall 212 , and the front end of the forming part formed at the front among the plurality of first forming parts 217a is It may be connected to an inner edge of the outer wall 212 .

In addition, left and right edges of the plurality of second forming parts 217b may be spaced apart from the inner edge of the external elevated wall 212 by a predetermined distance. In addition, the front end of the forming part formed at the front among the plurality of second forming parts 217b may be connected to the partition wall 213 with . In addition, the rear end of the forming portion formed at the rearmost among the plurality of second forming portions 217b may be connected to the inner edge of the outer wall 212 .

In addition, a plurality of avoiding holes 218a may be formed in the plurality of strength reinforcing parts 217 . The plurality of avoiding holes 218a are holes for preventing interference with the head of the fastening member protruding from the bottom surface of the mass body 22 , for example, the head of the rivet. Also, since the mass body 22 reciprocates in the left and right directions, each of the avoiding holes 218a may be formed in the form of an ellipse or a long hole having a long side corresponding to the movement distance (displacement) of the mass body 22 .

In addition, one or a plurality of drain holes are formed in the plate body 211 corresponding to the mass body accommodating part 214 , so that moisture formed in the dynamic absorber 20 can be quickly discharged to the outside.

In addition, a supporter mounting part 219 may be formed in any one of the plurality of first forming parts 217a. The formation position of the supporter mounting part 29 is determined according to the mounting position of the supporter 28 , and in this embodiment, two supporter mounting parts 219 are formed to be spaced apart from each other in the left and right directions of the support plate 21 .

The supporter mounting part 219 includes a roller hole 219a, a pair of hook holes 219c respectively formed in front and rear of the roller hole 219a, and the roller hole 219a and the hook hole 219c. ) may include a pair of roller shaft support (219b) formed between.

In addition, a plurality of slider fastening holes 218b may be formed in the second forming part 217b. The slider fastening hole 218b is a hole for fixing the slider 29 to the support plate 21 .

Meanwhile, a plurality of fastening slits 216 may be formed on each of the left and right edges of the mass body accommodating part 214 .

In detail, the plurality of fastening slits 216 are formed at a point adjacent to the inner edge of the outer wall 212 , and the plurality of elastic dampers 25 are fitted and coupled to the plurality of fastening slits 216 . .

Each of the plurality of fastening slits 216 may have a T-shape or an I-shape including a long side and a short side formed at an end of the long side in a direction crossing the long side. Since the fastening slit 216 has a T-shape or an I-shape, a fastening box (to be described later) protruding from the bottom surface of the elastic damper 215 can be easily inserted. A method of inserting the fastening arm of the elastic damper 215 into the fastening slit 216 will be described below with reference to the drawings.

In addition, since the support plate 21 is fixed to the upper surface of the side cabinet 112 , the vibration of the cabinet 11 is transmitted to the support plate 21 to vibrate together with the cabinet 11 . .

Here, the primary mode resonance frequency of the support plate 21 is formed to be greater than the maximum rotation frequency of the drum, so that self-resonance of the support plate 21 can be avoided within the rotation section of the drum. As an example, the primary mode natural frequency (or primary mode resonance frequency) of the support plate 21 may be in the range of 20 Hz to 30 Hz.

8 is a plan view of a first mass according to an embodiment of the present invention, and FIG. 9 is a perspective view of the first mass.

8 and 9 , the first mass body 23 that absorbs normal vibrations among the mass bodies 22 according to an embodiment of the present invention may have a rectangular shape with rounded corners.

In detail, the first mass 23 may be made of a metal material having a high density in order to secure sufficient mass within a limited space inside the cabinet 11 . In addition, the first mass 23 may be a single mass by casting, or may be formed by stacking a plurality of thin metal plates.

When the first mass 23 is formed by stacking a plurality of thin metal plates, the plurality of thin metal plates are combined as a single body by the rivet part 231 . Also, the four corners of the mass body 22 are shown to be rounded, but the present invention is not limited thereto. And, the number of the rivets 231 is appropriately set according to the number and size of the laminated metal thin plates, so that a plurality of thin metal plates do not shake or cause friction, and function the same as a single mass.

In addition, a plurality of guide hole units may be formed in a central portion of the first mass 23 . In addition, each of the guide hole units may include a plurality of guide holes 233 .

The plurality of guide hole units may be disposed on a line that bisects the first mass body 23 in the front-rear direction, and is symmetrical to the left and right with respect to the line that bisects the first mass body 23 in the left-right direction. It can be placed in a position where

The guide hole unit is a part on which the supporter 28, which will be described later, is mounted. The supporter 28 enables the first mass 23 to stably move while maintaining a horizontal state. A single guide hole unit may be formed in the center of the mass body 23 , but in this case, the first mass body 23 is tilted up and down while reciprocating in the left and right directions to interfere with the support plate 21 . can Accordingly, it is preferable that at least two guide hole units are formed. In this embodiment, it is proposed that two guide hole units are disposed on the left and right sides of the mass body 23 , respectively.

On the other hand, the guide hole 233 constituting the guide hole unit may be formed in the form of a long hole having a long side and a short side, and the length d of the long side of the guide hole 233 is the length d of the mass body 23 . It responds to movement displacement. That is, when the horizontal vibration is transmitted to the cabinet 11 , the first mass 23 may swing in the left and right directions by the length of the guide hole 233 .

On the other hand, although the first mass 23 horizontally vibrates in the left and right directions, there is no vibration in the vertical direction. When a vertical vibration is applied to the first mass 23 , the upper surface of the first mass 23 may collide with the top plate 12 to cause noise. To prevent this, a buffer pad 234 may be separately attached to the upper surface of the first mass 23 .

The buffer pad 234 is also attached to the bottom surface of the first mass 23 , so that the central portion of the first mass 23 sags due to a load or a vertical direction acting on the vibration first damper 23 . It is possible to prevent the mass body 23 from directly colliding with the support plate 21 due to vibration. The buffer pad 234 may include a nonwoven fabric, a viscoelastic member, silicone, or the like.

It should be noted that the buffer pad 234 may be mounted on at least one of an upper surface and a lower surface of the second mass body 23 which will be described later.

In addition, one or a plurality of buffer member holes 232 may be formed in the first mass 23 , and the buffer member holes 232 will be described in detail with reference to the drawings below. The buffer member hole 232 may also be formed in the second mass 24 .

10 is a view showing a buffer structure against vertical vibration of the first mass according to an embodiment of the present invention, and FIG. 11 is a longitudinal cross-sectional view taken along lines 11-11 of FIG. 10 .

10 and 11 , the buffer member hole 232 may be formed in the first mass 23 , and the buffer pin 235 may be inserted into the buffer member hole 232 .

In detail, the buffer pin 235 includes a pin body 235a having an outer diameter corresponding to the diameter of the buffer member hole 232 , and an upper buffer portion 235b formed at an upper end of the pin body 235a and , may include a lower buffer portion 235c formed at the lower end of the pin body 235a.

In more detail, at least the upper buffer part 235b and the lower buffer part 235c among the buffer pins 235 may be made of the same material as the buffer pad 235 . And, the outer diameter of the lower buffer part 235c may be formed to be larger than the outer diameter of the pin body 235a, and the upper end of the upper buffer part 235b is spaced apart from the bottom surface of the top plate 12. It may be formed to be higher than the upper surface of the first mass 23 .

And, in a state in which the buffer pin 235 is coupled to the first mass 23 , the lower buffer 235c is spaced apart from the upper surface of the support plate 21 .

Here, the upper buffer part 235b may be provided as a separate part having an outer diameter greater than the diameter of the buffer member hole 232 and be fastened to the upper end of the pin body 235a. In this case, the lower buffer part 235c may be formed as a single body with the pin body 235a.

As another method, the upper buffer part 235b and the pin body 235a are formed as one body, and the lower buffer part 235b is made of a separate member and is fastened to the lower end of the pin body 235a. It is possible.

As such, when the buffer pin 235 is inserted into the buffer member hole 232 , when no vertical vibration is applied to the first mass 23 , the upper and lower ends of the buffer member 235 are It does not touch the top plate 12 and the support plate 21 . That is, only when the vertical vibration acts on the first mass 23 , the upper end and the lower end of the buffer pin 235 intermittently contact the top plate 12 and the support plate 21 .

It should be noted that the structure of the buffer pin 235 may be provided in the same manner to the second mass 24 .

12 is a cross-sectional view illustrating a separation preventing structure for preventing a mass from being separated from a support plate during a transport process of the laundry treatment apparatus.

The separation preventing structure may be equally applied to the second mass as well as the first mass.

Referring to FIG. 12 , at least one long hole-shaped through hole 220 having the same shape as the guide hole 233 (refer to FIG. 8 ) may be formed in the mass body 22 . That is, the through hole 220 may have long and short sides of the same length as the long and short sides of the guide hole 233 . In detail, the length d of the long side of the guide hole 233 may be the same as the length of the long side of the through hole 220 .

In addition, a fastening member V such as a bolt may pass through the through hole 220 . In addition, the fastening member V may be inserted and fixed to the support plate 21 through the through hole 220 from the upper surface of the mass body 22 . In addition, the body of the fastening member V accommodated in the through hole 220 may have the same diameter as a guide boss (to be described later) of the supporter 28 fitted into the guide hole 233 .

In addition, the outer diameter of the head of the fastening member V is formed to be at least larger than the length of the short side of the through hole 220 , so that the mass 22 is separated from the fastening member V during the vibrating process. can be prevented from becoming

According to the structure as described above, even when the laundry treatment device 10 is turned over or overturned sideways in the process of transporting the laundry treatment device 10 to which the dynamic absorber 20 is mounted, the mass body 22 is not separated from the support plate 21 .

In addition, since the length of the long side of the through hole 220 is the same as the length of the long side of the guide hole 233 , the mass 22 oscillates in the left and right directions to absorb the vibration of the cabinet 11 . It does not act as an obstacle in the process. That is, a phenomenon in which the fastening member V collides with the mass body 12 does not occur. In this case, the maximum vibration displacement of the mass body 22 in the horizontal direction is limited by the elastic damper 25 , and the length d of the long side of the through hole 220 is the maximum vibration displacement of the mass body 12 . Because it is formed larger.

13 is a perspective view of a second mass according to an embodiment of the present invention.

Referring to FIG. 13 , the second mass 24 according to the embodiment of the present invention is mainly provided to absorb excessive vibration acting on the cabinet 11 .

In detail, the second mass 24 has a smaller mass than the first mass 24, and at a rotational speed lower than the rotational speed (rpm) (or rotational frequency) of the drum at which the first mass 23 operates. It works.

In addition, the second mass 24 may also have a rectangular shape with rounded corners, similarly to the first mass 23 , and may have a structure in which a single mass made of a metal material or a plurality of thin metals are stacked.

In addition, when the mass body 24 is formed by stacking a plurality of thin metals, the plurality of thin metals may be combined as a single body by the rivet part 241 .

Meanwhile, a plurality of sliders 29 may be mounted on the bottom surface of the second mass 24 , and a plurality of slider fastening holes 242 may be formed in each portion where the sliders 29 are mounted.

14 is a plan perspective view of a supporter according to an embodiment of the present invention, FIG. 15 is a bottom perspective view of the supporter, FIG. 16 is an exploded perspective view of the supporter, and FIG. It is also

14 to 17 , the supporter 28 according to the embodiment of the present invention is provided on the bottom surface of the mass body for absorbing normal vibration.

In detail, the supporter 28 is installed on the bottom surface of the first mass 23 to minimize the generation of frictional force when the first mass 23 vibrates in the left and right directions. Maximizes vibration absorption.

In addition, the supporter 28 prevents the first mass 23 from sagging due to its own weight, and functions to vibrate the first mass 23 only in the horizontal direction as much as possible.

The supporter 28 may include a roller support portion 282 fixed to the supporter mounting portion 219 of the support plate 21 and a guide roller 281 rotatably seated on the roller support portion 282 . have.

The guide roller 281 includes a roller 281a and a roller shaft 281b passing through the center of the roller 281a. The roller 281a makes linear contact with the bottom surface of the first mass 23 and rotates together with the first mass 23 . The guide roller 281 is provided to minimize the frictional force generated between the first mass 23 and the supporter 28, but in addition, a ball bearing capable of point contact with the first mass 23 may be applied. make it clear

In addition, the roller support 282 includes a seating plate 282a seated on the upper surface of the support plate 21, and at least one pair of extending downward from the front and rear ends of the seating plate 282a, respectively. It may include a fastening hook 282e, a receiving hole formed in the center of the seating plate 282a, and a plurality of guide bosses 282b protruding a predetermined length from the upper surface of the seating plate 282a.

In detail, although it is suggested that the fastening hooks 282e extend one by one to the front and rear ends of the seating plate 282a, the present invention is not limited thereto, and a plurality of fastening hooks 282e may be formed at each of the front and rear ends.

In addition, although it is suggested that the guide boss 282b also protrudes two on the left edge and the right edge of the seating plate 282a, the present invention is not limited thereto, and one of the guide bosses 282b may also protrude from the left edge and the right edge. In addition, the guide boss 282b is inserted into the guide hole 233 of the first mass 23 . Accordingly, the number of the guide holes 233 may be formed corresponding to the number of the guide bosses 282b. And, when the first mass 23 vibrates in the left and right directions, the guide boss 282b relatively moves in the guide hole 233 in the left and right directions. The diameter of the guide boss 282b may be formed to have a size corresponding to the length of the short side of the guide hole 233 .

In addition, the accommodating hole includes a roller shaft accommodating hole 282d extending in the front-rear direction from the center of the seating plate 282a to accommodate the roller shaft 282b, and a left and right direction from the center of the seating plate 282a. It may include a roller accommodating hole 282c extending to the accommodating the roller 281a.

Also, as shown in FIG. 15 , shaft support ribs 282f may protrude from the bottom left and right edges of the roller shaft accommodating hole 282d, respectively. In detail, a pair of shaft support ribs 282f extending from opposing points are respectively formed at the front end point and the rear end point of the roller accommodating hole 282c, the front of the roller 281a as the center The roller shaft 281b portion and the rear roller shaft portion can be supported, respectively. In addition, as shown in FIG. 17 , the roller shaft 281b is supported by the shaft support ribs 282f, and the roller shaft is formed to be rounded in an arc shape on the support plate 21 . It is also supported by the support part 219b.

Further, on the bottom surfaces of the left and right ends of the roller accommodating hole 282c, rocking prevention ribs 282g are respectively extended. The pair of oscillation prevention ribs 282g are caught on the left and right ends of the roller hole 219a formed in the support plate 21 to prevent the seating plate 282a from shaking in the left and right directions. have. If there is no oscillation prevention rib 282g, the fastening force of the pair of fastening hooks 282e should be considerably large. However, since the anti-vibration rib 282g is formed, it is sufficient that the pair of fastening hooks 282e only function to be caught on the support plate 21, and the phenomenon that the seating plate 282a is shaken in the left and right direction is It is prevented by the rocking prevention rib 282g.

18 is a plan perspective view of an upper slider constituting a slider according to an embodiment of the present invention, FIG. 19 is a bottom perspective view of the upper slider, FIG. 20 is a plan perspective view of a lower slider constituting the slider, and FIG. 21 is It is a bottom perspective view of the lower slider, and FIG. 22 is a longitudinal cross-sectional view taken along lines 22-22 of FIG. 3 .

18 to 22 , the slider 29 according to the embodiment of the present invention is mounted on the bottom surface of a mass that absorbs excessive vibration. Accordingly, the slider 29 may be disposed on the bottom surface of the second mass 24 .

In detail, the slider 29 is formed in a form in which an upper slider 30 and a lower slider 31 are coupled, and the upper slider 30 and the lower slider 31 slide with respect to each other with a predetermined friction damping. Move.

The second mass 24 absorbs excessive vibration generated at the resonance point of the drum by the magnitude of the friction damping of the slider 29 . In addition, the excessive vibration absorption region (or absorption amplitude) is determined by the magnitude of the friction damping and the mass of the second mass 24 .

In detail, the upper slider 30 includes an upper slider body 301 having a substantially rectangular shape, a plurality of fastening protrusions 302 protruding from four corners of an upper surface of the upper slider body 301 , and the upper slider A plurality of slider rails 303 protruding from the bottom surface of the body 301 and extending in the longitudinal direction of the upper slider body 301 may be included.

In more detail, the plurality of fastening protrusions 302 may be inserted into the plurality of slider fastening holes 242 formed in the second mass 24 . The slider fastening holes 242 may be formed in the second mass body 24 in a number corresponding to the number of the fastening protrusions 302 .

In addition, a plurality of slider fastening holes 242 corresponding to the number and positions of the fastening protrusions 302 may form one slider fastening hole group. In addition, a plurality of slider fastening hole groups may be formed in the second mass body 24 so that the upper slider 30 can be coupled to the bottom surface of the second mass 24 at various positions.

The fastening protrusion 302 may protrude from four corners of the upper surface of the upper slider body 301 , but is not limited thereto. As another example, in the three-point support type, one fastening protrusion protrudes from the center of one edge of the upper surface of the upper slider body 301 and the fastening protrusion protrudes from two corners of the opposite edge, respectively.

As another method, two or more fastening protrusions are arranged in one row in the width direction from the center of the upper surface of the upper slider body 301 , or two or more fastening protrusions are arranged in one row in the longitudinal direction.

In addition, two of the slider rails 303 may form a pair and be inserted into a rail receiving groove 312 (to be described later) formed in the lower slider 31 . When the slider rail 303 is accommodated in the rail accommodating groove 312 , the second mass 24 moves on the support plate 21 to obtain a phase opposite to that of the excitation force generated by the rotational force of the drum. It can swing in the horizontal direction with Also, when the slider rail 303 is accommodated in the rail receiving groove 312 , it is possible to prevent the second mass 24 from swinging in the front-rear direction of the cabinet 11 .

Although it is shown that two slider rails 303 are accommodated in the rail accommodating groove 312, the present invention is not limited thereto, and it should be noted that a structure in which three or more slider rails 303 are accommodated is also possible.

Also, the lower slider 31 may have a rectangular shape having the same size as that of the upper slider 30 .

In detail, the lower slider 31 includes a lower slider body 311 having the same shape as that of the upper slider body 301 , and the upper surface of the lower slider body 311 in the longitudinal direction of the lower slider body 311 . It may include a rail receiving groove 312 formed to extend and a plurality of fastening protrusions 314 protruding from the bottom surface of the lower slider body 311 .

Here, the protrusion length of the slider rail 303 of the upper slider 30 may be equal to or slightly longer than the depression depth f of the rail receiving groove 312 . In addition, the depression depth f of the rail accommodating groove 312 is preferably formed to be greater than a gap between the upper surface of the second mass 24 and the bottom surface of the top plate 12 . In that case, the slide rail 303 is prevented from being separated from the rail accommodating groove 312 even when the laundry treatment device 10 is turned or tilted during the movement of the laundry treatment device 10 . can

In more detail, the plurality of fastening protrusions 314 may be formed in the same shape and in the same number at the same formation position as the plurality of fastening protrusions 314 formed on the upper slider 30 . Accordingly, a redundant description of the plurality of fastening protrusions 314 formed on the lower slider 31 will be omitted. Of course, in the support plate 21 , specifically, in the second forming part 217b of the support plate 21 , a plurality of slider fastening holes 218b for inserting the plurality of fastening protrusions 314 are formed. do. In addition, the plurality of slider fastening holes 218b may be formed at a plurality of positions in groups corresponding to the number of the lower sliders 31 .

In addition, a plurality of the rail receiving grooves 312 may be arranged side by side with a width smaller than the width of the slider body 311 . In other words, the rail accommodating groove 312 may be divided into a plurality of small rail accommodating grooves by the partition wall 313 .

In this embodiment, it is disclosed that the two rail accommodating grooves 312 are arranged side by side in the width direction of the slider body 311, but it is not excluded that three or more rail accommodating grooves are arranged side by side. Of course, it is not excluded that the partition wall 313 is not formed and a single rail accommodating groove 312 is formed.

In addition, two or more slider rails 303 are accommodated in each rail receiving groove 312 , and at least two slider rails 303 are in contact with the front edge and rear edge of the rail receiving groove 312 . can make it happen

That is, the front side rail of the at least two slider rails 303 accommodated in the rail receiving groove 312 is in contact with the front edge of the rail receiving groove 312 , and the rear side rail is the rail receiving groove 312 . may be in contact with the rear edge of For example, when three slider rails are formed, two may be in contact with the front and rear surfaces of the rail accommodating groove 312 , and the other may be disposed in the center of the rail accommodating groove 312 .

In this way, the front and rear surfaces and the bottom surfaces of the at least two slider rails 303 are brought into contact with the front and rear surfaces and the bottom surfaces of the rail accommodating grooves 312 , so that the second mass 24 is moved in the left and right directions (the length of the slider). direction), damping by frictional force acts to absorb excessive vibration.

The frictional force generated by the slider 29 acts as an attenuation of the second mass 24 . In addition, the damping of the second mass 24 acts as a variable determining the vibration displacement of the transient vibration. In addition, the friction coefficient of the friction force determines the magnitude of the damping, and the greater the damping (or damping value), the better the ability of the dynamic absorber 20 to absorb excessive vibration.

Of course, since the elastic damper 23 also has damping for absorbing excessive vibration as well as elasticity (or rigidity), it affects the improvement of excessive vibration, but it can be said that it is significantly smaller than the damping caused by friction. Therefore, the elastic damper 23 can be said to be a damper that mainly affects the improvement of the normal vibration transmitted by the dynamic damper 20 to the cabinet 11 .

In addition, the effect of preventing the second mass 24 from swinging in the front-rear direction of the laundry treatment apparatus 10 (the front-rear width direction of the slider) can be obtained.

In addition, the upper slider 30 and the lower slider 31 may be formed of an engineering plastic made of polyoxymethylene (POM) material. Also, since noise may be generated when plastics of the same material are in contact with each other, a lubricant such as grease may be applied to the rail accommodating groove 312 .

On the other hand, the length of the rail receiving groove 312 is formed to be longer than the length of the slider rail 303 , so that the upper slider 30 can reciprocate on the lower slider 31 in the left and right directions. This is because, if the upper slider 30 does not move left and right on the lower slider 31 , the second mass 24 cannot vibrate in a phase opposite to that of the cabinet.

In detail, a value obtained by subtracting the length of the slider rail 303 from the length of the rail accommodating groove 312 in the left and right directions is equal to or greater than the movement displacement of the second mass 24 .

23 is a plan perspective view of a second elastic damper according to an embodiment of the present invention, and FIG. 24 is a bottom perspective view of the second elastic damper.

23 and 24 , the dynamic absorber 20 according to the embodiment of the present invention includes a second elastic damper 27 that can be mounted on the side of the mass for absorbing excessive vibration.

The second elastic dampers 27 constituting the dynamic damper 20 according to the embodiment of the present invention may be disposed at left and right edges of the second mass 24 .

In detail, when the second mass 24 oscillates in the left and right directions, the left and right edges of the second mass 24 collide with the second elastic damper 27 . At this time, the second elastic damper 27 is elastically deformed to absorb the impact of the second mass body 24 .

In addition, two of the second elastic dampers 27 may be disposed on the left edge and the right edge of the second mass 24, respectively, but the present invention is not limited thereto, and three or more may be disposed. . For example, the second mass body 24 may be disposed at the rear end, the center portion, and the front end of both side edges of the second mass 24 , respectively.

In addition, the second elastic damper 27 may have a hexahedral shape including a front portion 271 , a rear portion 274 , a side portion 272 , an upper surface portion 273 , and a bottom surface portion 279 . In addition, an inclined portion 275 may be formed or formed to be rounded at a corner portion where the front portion 271 and the upper surface portion 273 meet.

In addition, a round portion 276 or an inclined portion may be formed at a corner portion where the bottom portion 279 and the rear portion 274 meet. As the inclined portion 275 is formed, when a horizontal force of the second mass 24 is applied to the front portion 271 , the shape of the second elastic damper 27 is deformed and rises and rises to the top plate The phenomenon of interference with (12) can be prevented.

In addition, as the round part 276 is formed, when the horizontal force of the second mass 24 is applied to the front part 271 , the bottom edge of the rear end of the second elastic damper 27 protrudes. Interference with the edge of the side edge of the mass body mounting part 241 may be prevented.

In addition, the second elastic damper 27 includes an elastic groove 277 that is depressed upwardly from the bottom 279, and a fastening arm protruding from the bottom 279 and fitted into the fastening slit 216. (278) may be further included.

In detail, the elastic groove 277 facilitates the shape deformation of the second elastic damper 27 when the second mass 24 swings in the horizontal direction and presses the front portion of the second elastic damper 27 . It is formed to make the shock absorption better. The elastic groove 277 may be defined as a shock absorbing groove, may be formed with a predetermined width in the left and right and front and rear directions, and may be recessed upward to a predetermined depth.

The elastic groove 277 may be formed at a position adjacent to the front portion 271 rather than the rear portion 274 to facilitate shock absorption of the second mass 24 . In addition to the structure in which the elastic groove 277 is opened from the bottom surface of the second elastic damper 27 and depressed upward, a structure in which the elastic groove 277 is opened from the upper surface of the second elastic damper 27 and is depressed downward is also possible. do. For example, it is revealed that it is also possible to be opened in the inclined portion 275 and to be depressed to a predetermined depth downward.

In addition, the fastening arm 278 may include an extended end 278a extending a predetermined length from the bottom portion 279, and a locking protrusion 278b extending from a side edge of the end of the extended end 278a. can

That is, the longitudinal height of the fastening arm 278 may be formed in an inverted T-shape, but is not necessarily limited thereto. When the longitudinal cross-section of the fastening arm 278 has an inverted T-shape, the fastening slit 216 has a T-shape or an I-shape, so that the fastening arm 278 can be inserted much more easily.

In detail, in order to couple the fastening arm 278 to the fastening slit 216 , first, the second elastic damper 27 is tilted at an angle so that the end of the locking protrusion 278b is the short side of the fastening slit 216 . to be located in the In this case, the extension end 278a is positioned on the long side of the fastening slit 216 . In this state, the second elastic damper 27 is pushed so that the locking protrusion 278b is inserted into the short side of the fastening slit 216 and at the same time the second elastic damper 27 is in a horizontal state. It moves along the long side of the fastening slit 216 . And, when the second elastic damper 27 is completely horizontal, the second elastic damper 27 is completely inserted into the fastening slit 216 .

In addition, in order to prevent the second elastic damper 27 from swinging in the vertical direction while it is coupled to the support plate 24 , the length of the extension end 278a is determined by the thickness of the support plate 24 . It can be made to be of a corresponding length. In other words, the distance from the bottom portion 279 to the upper end of the locking protrusion 278b may be set equal to the thickness of the support plate 24 .

In addition, the fastening arm 278 may be formed at a point closer to the rear portion 234 than the front portion 271 of the second elastic damper 27 , but is not limited thereto.

25 is a plan perspective view of a first elastic damper according to an embodiment of the present invention, FIG. 26 is a bottom perspective view of the first elastic damper, and FIG. 27 is a longitudinal cross-sectional view taken along lines 27-27 of FIG. 25 .

25 to 27 , the first elastic damper 26 according to an embodiment of the present invention may be mounted on a side surface of a mass that absorbs normal vibrations.

In detail, the first elastic damper 26 may include a side support part having the same shape as the second elastic damper and a bottom support part extending horizontally from the side support part.

In addition, two of the first elastic dampers 26 may be disposed on the left edge and the right edge of the first mass 23, respectively, but the present invention is not limited thereto, and three or more may be disposed. . For example, the first mass body 23 may be respectively disposed at the rear end, the central portion, and the front end of both side edges of the first mass 23 .

Also, the side support portion of the first elastic damper 26 may have the same shape as that of the second elastic damper 27 . That is, the side support portion of the first elastic damper 26 may have a hexahedral shape including a front portion 261 , a rear portion 264 , a side portion 262 , an upper surface portion 263 , and a bottom surface portion 269 . can In addition, an inclined portion 265 may be formed or formed to be rounded at a corner portion where the front portion 261 and the upper surface portion 263 meet.

In addition, the first elastic damper 26 may further include an elastic groove 266 and a fastening arm 268 . In detail, the elastic groove 266 may be depressed downwardly from the upper surface portion 263 by a predetermined depth, or may be depressed upwardly from the bottom surface portion 269 to a predetermined depth.

In addition, the fastening arm 268 may include an extended end 268a and a locking protrusion 268b, and the method of inserting the fastening arm 268 into the fastening slit 216 is to fasten the fastening arm 278 . The method of inserting into the slit 216 is the same.

Meanwhile, the bottom support part is a part that supports the bottom edge of the first mass 23 and may include a horizontal part 269a and a vertical part 269b.

In detail, the horizontal part 269a may extend horizontally from the front part 261 , and the vertical part 269b may extend downward from an end of the horizontal part 269a. In addition, the horizontal portion 269a may be designed to be elastically deformable by extending horizontally at a point spaced upward from the lower end of the front portion 261 .

The first mass 23 has a relatively larger mass than the second mass 24 and operates at high speed rotation. That is, the drum vibrates at a high frequency in order to catch the normal vibration that occurs when the drum is maintained at the maximum speed. In this case, not only horizontal vibration but also vertical vibration may occur in the first mass 23 . When the vertical vibration occurs, left and right ends of the first mass 23 may come into contact with the support plate 21 to generate noise. To prevent this, the bottom support part may support the bottom surfaces of the left and right edges of the first mass 23 .

Of course, when the first mass 23 is horizontally maintained by the supporter 28 , the second elastic damper 27 is positioned on the side surface of the first mass 23 instead of the first elastic damper 26 . may be placed in Ideally, it is advantageous in terms of reducing frictional damping to not come into contact with the horizontal portion 269a while the first mass 23 swings in the left and right directions. However, when the first mass 23 vibrates in a horizontal state, it is maintained to be spaced apart from the horizontal portion 269a, and the horizontal portion 269a is maintained only when the horizontal state of the first mass 23 is broken. By making contact with , you will be able to achieve both purposes.

Hereinafter, a method for improving vibration by effectively absorbing excessive vibration and normal vibration generated in the cabinet 11 by the dynamic absorber 20 will be described.

Equation 1 below is a dimensionless response expression showing the behavior of the dynamic reducer 20 to vibrations generated when a drum having an eccentric load rotates.

,

,

,

,

,

,

,

,

Y: dimensionless oscillatory displacement (or amplitude) of the mass,

r : operation speed ratio (or operation frequency ratio)

ω: rotational speed (or rotational frequency) of the drum

ω _a : natural frequency (or natural frequency) of the mass

ω _p : natural frequency (or natural frequency) of the laundry treatment device

β : frequency ratio (or frequency ratio)

μ: mass ratio

ma _a : mass of mass

m _p : mass of the laundry treatment unit

ζ : damping ratio

c _a : mass attenuation

The dimensionless response equation of the dynamic reducer uses a mass ratio, a frequency ratio, and a damping ratio as variables. The mass ratio is strictly defined as the mass ratio of the mass body 22 to the mass of the laundry treatment device 10, but In terms of mass ratio, it is irrelevant.

This is because elements of the dynamic absorber 20 except for the mass 22 are fixed to the laundry treatment apparatus 10, and thus can be viewed as a part of the mass of the laundry treatment apparatus 10, and the laundry treatment This is because it has little influence on determining the overall mass of the device 10 . This is because the upper slider 30 also has a mass that is negligible compared to the mass of the mass body 22 . Therefore, it should be noted that the mass ratio may be interpreted as the mass ratio of the dynamic reducer 20 .

In addition, it should be noted that the frequency ratio and damping ratio may also be defined or interpreted as the frequency ratio of the dynamic absorber 20 and the damping ratio of the dynamic reducer 20, similarly to the mass ratio.

On the other hand, the shape of the response curve drawn by the response equation is determined by the mass ratio, the frequency ratio, and the damping ratio, and the vibration absorption capacity of the dynamic absorber 20 is determined by these variables. That is, if the rotational speed ratio of the drum is increased while the mass ratio, the frequency ratio, and the damping ratio, which are the variables of the response equation, are appropriately selected, the dimensionless amplitude of the dynamic reducer is calculated. In addition, the calculated dimensionless value may be regarded as the vibration displacement of the cabinet 11 .

Here, the mass ratio of the dynamic absorber 20 is a design variable that determines the absorption region that absorbs the transient vibration, and the frequency ratio (or frequency ratio) and the damping ratio are designed to determine the vibration displacement of the secondary transient vibration after absorption is a variable. In detail, when the mass body (the second mass in the present invention) for absorbing excessive vibration of the dynamic absorber 20 operates at the resonance point, the excessive vibration is absorbed, and two secondary transients significantly smaller than the vibration displacement when the excessive vibration occurs. vibration occurs.

In addition, the distance between the two secondary transient vibrations is defined as an absorption region or an absorption width, and the size of the absorption region may vary depending on the mass ratio. And, the vibration displacement, that is, the peak point of the two secondary transient vibrations may be changed by adjusting the frequency ratio and the damping ratio.

For reference, on the response graph, the two second-order transient oscillations are represented by two peak points where the dimensionless amplitude value suddenly increases and then decreases. The interval between the two peak points is interpreted as an exhaust region, and the interval between the two peak points is changed by adjusting the mass ratio.

Meanwhile, the resonance frequency at which the excessive vibration occurs may vary depending on the size, mass, product deviation, and eccentricity of the laundry (load) put into the drum. In this situation, in order for the dynamic damper 20 to effectively absorb excessive vibration of the laundry treatment apparatus 10 to improve vibration, the vibration absorption region should be formed to be equal to or larger than the resonance frequency region.

Here, the absorption region of the dynamic reducer 20 includes a rotation frequency at which the second mass 24 starts to move in a direction opposite to the excitation force generated by the accelerated rotation of the drum, and the rotation speed of the drum. As α increases, vibration generated by the excitation force decreases, and thus it may be defined as a width between rotation frequencies at which the second mass 24 stops.

Here, the time point at which the mass body starts to move may be defined as a time point at which the mass body vibrates in a phase different from that of the cabinet 11 or the support plate 21 . In other words, the meaning of the time point at which the mass body stops may be defined as a time point at which the mass body starts to move in the same phase as the vibration phase of the cabinet 11 or the support plate 21 .

In addition, the factor determining the size of the excessive vibration absorption region of the dynamic damper 20 is the mass ratio. That is, the larger the mass ratio, the wider the excessive vibration damping area, and the smaller the mass ratio, the narrower the damping area. In other words, as the mass of the second mass 24 increases, it means that excessive vibration can be absorbed in a wide section.

The mass ratio may be increased in order to widen the dust absorption area, but there is a limitation in the internal space of the cabinet 11 in which the dynamic absorber 20 is mounted. In detail, since the dynamic reducer 20 is mounted on the upper surface of the cabinet 11 and the dynamic reducer 20 is covered by the top plate 12 , the planar area of the dynamic reducer 20 is There is a limitation that the thickness and thickness cannot be increased indefinitely.

Theoretically, if the mass of the dynamic absorber 20, specifically, the mass of the mass 21 and the total mass of the laundry treatment apparatus 10 to which the dynamic absorber 20 is mounted, is the same, the excessive vibration is most It can be completely absorbed.

However, when the mass of the mass body 21 is excessively large, the load of the laundry treatment apparatus 10 is too large, and thus movement and installation are difficult, and the second mass 21 may sag due to its own weight. Above all, there is a limit in increasing the load (or mass) of the second mass body 21 due to the limitation of the installation space inside the cabinet 11 .

In addition, when only the second mass body 21 is installed, excessive vibration may be improved, but a problem in that normal vibration may not be absorbed may occur. That is, there is a problem in that one mass cannot absorb both the transient vibration and the normal vibration.

28 is a graph showing the vibration displacement of a laundry treatment apparatus equipped with a dynamic damper including only a mass for absorbing excessive vibration.

The horizontal axis of the graph represents the rotational speed (rpm) of the drum, and the vertical axis represents the vibration displacement of the cabinet. The rotation speed may be regarded as the same concept as the rotation frequency.

Referring to FIG. 28 , graph A is a vibration displacement graph of a cabinet measured in a laundry treatment apparatus not equipped with a dynamic damper 20, and graph B is a laundry treatment apparatus equipped with a mass for absorbing excessive vibration having a predetermined mass ratio. It is a graph of the vibration displacement of the cabinet measured in

First, let's take a look at the case where the dynamic absorber is not installed.

The drum into which the laundry for rinsing or dehydration is put begins to rotate, and as the rotation speed increases, a horizontal excitation force is generated by the rotation of the eccentric laundry loaded into the drum. Also, the horizontal vibration displacement of the cabinet is increased by the excitation force.

And, when the rotational speed of the drum reaches the resonance frequency, the cabinet vibrates excessively due to resonance. On the graph, the resonance point at which the excessive vibration occurs is identified as a section between 800 rpm and 1000 rpm.

And, when the rotation speed of the drum exceeds the resonance frequency, the vibration is gradually reduced. And, in a section in which the drum is maintained at the maximum speed, the cabinet undergoes normal vibration in which the vibration displacement value hardly changes.

On the other hand, when the dynamic absorber is mounted, the vibration displacement of the cabinet 11 also increases as the rotation speed of the drum increases. And, in the low-speed section in which the dynamic damper does not start, the behavior of the vibration displacement graph is not significantly different from that in the case where the dynamic damper is not mounted.

However, when the rotation frequency (or rotation speed) of the drum falls within a frequency range where the motion of the dynamic reducer, ie, the mass, starts, the mass starts to move. Then, the increased vibration displacement of the cabinet decreases sharply, and as the rotation speed of the drum increases, the vibration displacement of the cabinet, which has decreased sharply, gradually increases again. That is, it can be seen that the excessive vibration generated when the dynamic absorber is not installed is absorbed by the dynamic absorber.

Then, the rotational speed of the drum continues to increase, and the vibration displacement of the cabinet increases until the vibration of the mass stops. When the rotational speed of the drum deviates from the absorption area of the dynamic absorber, the mass stops.

In detail, when the drum exceeds the resonant frequency, the vibration due to the excitation force is weakened and the vibration displacement of the cabinet is also reduced. Accordingly, when the rotational speed of the drum deviates from the excessive vibration absorption region of the dynamic damper 20, the vibration displacement of the cabinet decreases and then is maintained as the displacement in the normal vibration.

Here, looking at graph B, it can be seen that as the transient vibration is absorbed by the dynamic absorber 20, two inflection points a and b having a vibration displacement smaller than the vibration displacement in the transient vibration are formed. Vibrations at the two inflection points may be defined as secondary transient vibrations. In addition, it can be said that the two inflection points a and b correspond to two peak points appearing in the response curve. The distance (W) between two inflection points can be defined as a damping area or a damping width.

In detail, the two secondary transient oscillations appear at the initial point and the end point of exhaustion, respectively. The forward secondary transient vibration is a vibration that occurs because the mass body absorbs the vibration that has been increasing as it starts to move. And, the secondary transient vibration at the back is vibration that occurs because the mass body stops moving and the cabinet behaves under the same conditions as when the dynamic damper 20 is not mounted.

In addition, when the absorption region is widened through the adjustment of the mass ratio, the vibration displacement in the secondary transient vibration can be further reduced, and the time when the front secondary transient vibration occurs can be advanced to the low speed section. Then, there is an advantage in that the stability of the washing machine is improved compared to the case where excessive vibration occurs in the high-speed section.

In addition, by adjusting the frequency ratio and damping ratio, it is possible to control the vibration displacement in the rear secondary transient vibration to be significantly lower than the vibration displacement in the front secondary transient vibration.

Here, the two secondary transient vibrations are generated because the vibration absorption amount is the largest at the resonance point of the drum. That is, since the mass body 21 is designed to absorb the excessive vibration as much as possible by causing it to vibrate the most in the direction opposite to the direction of vibration generated by the excitation force at the resonance point where the excessive vibration occurs, both ends of the vibration absorption region It can be said that it is natural for the secondary transient vibration to occur in

29 is a graph showing the vibration displacement of a laundry treatment apparatus equipped with a dynamic absorber according to an embodiment of the present invention.

In detail, graph D is a graph showing the vibration displacement of the cabinet according to the rotational speed of the drum in a state in which the dynamic damper is not mounted, and it can be said that it corresponds to the graph A of FIG. 28 .

Graph E is a graph showing the vibration displacement of the cabinet when only a mass corresponding to the first mass, ie, a mass absorbing normal vibrations, is mounted.

And, graph F is a graph showing the vibration displacement of the cabinet that appears when the dynamic absorber 20 according to the embodiment of the present invention, that is, a mass absorbing normal vibration and a mass absorbing excessive vibration are separately mounted. to be.

In order to design to represent the vibration pattern of the cabinet as shown in graph E, first, only the first mass 23 is mounted to obtain the vibration displacement of the cabinet. That is, given the size of the support plate 21 , the distance between the support plate 21 and the top plate 12 , and the desired amount of normal vibration reduction, the mass ratio, the frequency ratio, and the damping ratio of the first mass are taken into consideration. etc. are set appropriately.

Then, the vibration displacement of the cabinet 11 moves from the graph D to the graph E, as shown. Referring to graph E, it can be seen that the normal vibration displacement is reduced by about 200 micrometers from t1 to t2 by the first mass. At this time, it can be seen that, although not large, the transient vibration displacement is also reduced by about 100 micrometers from h1 to h2 by the mounting of the first mass body, and at the same time, the transient vibration generating point is moved to a low speed section. Since the main target of the first mass is to absorb normal vibrations rather than transient vibrations, it can be seen that the first mass does not significantly affect the reduction of excessive vibrations.

In this state, the first mass 23 is included as a part of the mass of the laundry treatment device, and the mass ratio of the second mass 24, the frequency ratio, and the damping ratio are appropriately changed while being inputted into the response equation and the optimum mass This can be decided. And, when the vibration displacement of the cabinet 11 is measured while the second mass 24 is also mounted, the graph E shifts to the graph F.

In other words, it can be seen that the vibration pattern of the cabinet changes from the graph D when the dynamic reducer 20 is not mounted according to the embodiment of the present invention to the graph F when the dynamic reducer 20 is mounted.

Referring to graph F, by the operation of the second mass 24, excessive vibration that would have occurred between about 800 rpm and 900 rpm is absorbed, so that two secondary transient vibrations with small vibration displacement are generated. In addition, the peak point of the rear secondary transient vibration among the two secondary transient vibrations can be further reduced through appropriate adjustment of the mass ratio, the frequency ratio, and the damping ratio.

Also, it can be seen that the normal vibration is reduced from t1 to t3 by the first mass 23 . Also, from the fact that the normal vibration is reduced from t2 to t3, it can be seen that the second mass 24 also contributed to some extent in absorbing the stationary vibration, although it is not large.

Meanwhile, since the size of the support plate 21 on which the first mass body 23 and the second mass body 24 are seated is limited, the total size of the mass body accommodating part 214 formed on the support plate 21 is limited. The mass ratio of the first mass body 23 and the second mass body 24 must be appropriately adjusted from the maximum mass of the corresponding mass body. In addition, since the mass of the first mass 23 for absorbing the normal vibration must be greater than the mass of the second mass 24 for absorbing the transient vibration, the second mass 24 itself cannot be covered. There is a limit to increasing the possible transient vibration absorption amplitude.

In order to overcome this, the behavior section of the second mass body 24 and the behavior section of the first mass body 23 are partially overlapped, so that the first mass body 23 partially contributes to increasing the excessive vibration absorption amplitude. can make it As a result, the effect of maximizing the vibration improvement efficiency of the cabinet 11 can be obtained.

Referring back to graph 29, when the drum starts to rotate and is gradually accelerated, the vibration of the cabinet 11 is gradually increased by the excitation force generated by the eccentric load applied to the inside of the drum.

In addition, when the rotational speed of the drum increases to a certain extent (about 800 rpm in the drawing), left-right movement (or vibration) of the second mass 24 starts. In addition, the second mass 24 vibrates greatly at the resonance point where the excessive vibration occurs to absorb the excessive vibration. Then, the forward secondary transient vibration (peak point k1) occurs, and the vibration displacement of the cabinet 11 decreases and then increases again.

Here, the motion of the first mass 23 starts at the point where the motion of the second mass 24 ends, that is, at about 950 rpm in the drawing. In addition, the second mass 24 stops at approximately 1050 rpm to 1100 rpm, and after that, only the first mass 23 moves. Then, at the point where the rear secondary transient vibration occurs, the first mass 23 contributes to absorbing the transient vibration of a certain level, although it is not large. As a result, there is an advantage in that the secondary transient vibration (peak point k2) at the rear side is not only disappeared to the extent that it hardly appears, but also the transient vibration region is widened.

In the drawing, W1 represents a transient vibration damping region (section in which the second mass moves), W2 represents a normal vibration damping region (section in which the first mass moves), and W3 represents an overlapping section (a section in which the first and second masses move). section to exercise together).

In order to obtain the above result, that is, the cabinet vibration aspect of graph F, the design condition of the dynamic reducer 20 is set using the response equation shown in Equation 1, and the dynamic reducer 20 is set as the set design condition. As a result of manufacturing and directly measuring vibration, the following design conditions were obtained.

First, looking at the design variable area for normal vibration improvement, the mass ratio of the first mass body 23 is 4% to 10%, the frequency ratio (or frequency ratio) is 0.8 to 1.5, and the damping ratio is 0% to 20%. can be set.

When the mass ratio of the first mass 23 is less than 4%, the absorption width that the first mass 23 can cover is too narrow, so that the overlapping area with the second mass 22 disappears and the second mass 23 (22) may cause a problem that does not help to absorb the transient vibration. In addition, there may be a problem in that normal vibrations occurring in a region outside the coverable absorption range cannot be absorbed.

On the other hand, the maximum value of the mass ratio of the first mass body 23 is 10% due to the internal space constraint of the laundry treatment device 10 in which the dynamic absorber 20 is mounted and the overall weight limitation of the laundry treatment device 10 . It is preferable to set it to

In addition, since the normal vibration generated in the laundry treatment apparatus 10 occurs a lot within the range of approximately 900 rpm to 1300 rpm, the first mass 23 should be designed to absorb the normal vibration generated in the region. However, when the frequency ratio of the first mass 23 is less than 0.8 or exceeds 1.5, the target absorption area is out of the section in which the normal vibration occurs, and thus the normal vibration cannot be absorbed.

In addition, looking at the design variable area for improving transient vibration, the mass ratio of the second mass 24 may be set to 2% to 5%, the frequency ratio to 0.5 to 1, and the damping ratio to 20% to 50%. Similarly to the reason for setting the mass ratio of the second mass body 24 , when the mass ratio of the second mass body 23 is less than 2%, the absorption width is excessively narrowed, and a region in which excessive vibration cannot be absorbed may occur. In addition, the maximum mass ratio was set not to exceed 5% due to a spatial constraint inside the laundry treatment apparatus and a weight limitation of the laundry treatment apparatus.

Also, a mass ratio of the second mass 24 to the first mass 23 may be set to 40% to 60%. In addition, the internal space of the cabinet of the laundry treatment apparatus 10 to which the dynamic absorber 20 is mounted is limited, in particular, the area of the support plate 21 , the support plate 21 and the top plate 12 . It is important to appropriately set the mass ratio between the first mass body 23 and the second mass body 24 in a state in which the interval between them is determined.

When the mass ratio of the second mass 24 to the first mass 23 is set to less than 40%, the normal vibration absorbing ability is improved, but a rotational speed region in which excessive vibration is not absorbed occurs. Conversely, when the mass ratio of the second mass body 24 to the first mass body 23 exceeds 60%, the ability to absorb transient vibrations is improved, whereas the mass of the first mass body 23 decreases due to a decrease in the mass of the first mass body 23 . The natural frequency of the mass 23 is increased. As a result, the frequency ratio of the first mass 23 increases, so that the normal vibration absorption region moves to a high frequency section, that is, a high-speed section, and a rotational speed region in which the normal vibration cannot be absorbed occurs. In addition, when the normal vibration absorption region moves to the high-speed section, an overlapping region where the motion section of the second mass body 24 and the motion section of the first mass body 23 overlap is lost.

In addition, the vibration frequency ratio and damping ratio of the first damper 23 and the second damper 24 are the elastic modulus and damping of the elastic damper 25 , the elastic modulus and damping of the supporter 28 and the slider 29 . It can be implemented by the complex design of

For example, the hardness of the first elastic damper 26 is preferably set within the range of 30 to 60 under the condition that the first elastic damper 26 is manufactured to have a shape as shown. In addition, the hardness of the second elastic damper 27 is preferably set within the range of 20 to 50 under the condition that the second elastic damper 27 is manufactured to have a shape as shown.

In addition, it is preferable that the supporter 28 applies a roller or a ball bearing to minimize frictional force, and the slider 29 generates an appropriate kinetic frictional force to cover the set excessive vibration damping area.

Claims (18)

cabinet;
a drum accommodated inside the cabinet;
a tub for accommodating the drum; and
and a dynamic absorber provided to absorb the vibration of the cabinet;
The dynamic absorber,
a support plate coupled to the cabinet;
a mass movably placed on the support plate to absorb vibration transmitted to the cabinet; and
and a supporter placed between the mass body and the support plate to support the mass body,
The supporter is
a guide roller including a roller in line contact with a bottom surface of the mass body and a roller shaft penetrating a center of the roller so that the mass body has a low damping ratio; and
It is mounted on the support plate and includes a roller support for supporting the roller shaft,
The roller support part,
a seating plate fixed to the upper surface of the support plate;
a plurality of guide bosses protruding from the upper surface of the seating plate and inserted into the mass body; and
Laundry treatment apparatus including a receiving hole for accommodating the guide roller. delete delete delete delete The method of claim 1,
The roller support part,
and a fastening hook extending from the bottom surface of the front end and the bottom of the rear end of the seating plate, respectively, passing through the support plate,
The receiving hole is
a roller receiving hole extending in the left and right direction of the seating plate from the central portion of the seating plate;
Laundry treatment apparatus including a roller shaft accommodating hole formed in the center of the seating plate in a direction orthogonal to the roller accommodating hole. 7. The method of claim 6,
A hook hole into which the fastening hook is inserted is formed in the support plate,
The fastening hook is inserted into the hook hole, the laundry treatment apparatus, characterized in that caught on the bottom surface of the support plate. 7. The method of claim 6,
Laundry treatment apparatus, characterized in that the mass body is formed with a guide hole in the form of a long hole into which the plurality of guide bosses are inserted. 7. The method of claim 6,
The roller support part,
Further comprising a pair of anti-vibration ribs extending from the bottom surface of the seating plate corresponding to the left end and the right end of the roller receiving hole,
A roller hole in which the roller is accommodated is formed in the support plate,
The pair of rocking prevention ribs is a laundry treatment apparatus, characterized in that it is caught on the left edge and the right edge of the roller hole. 7. The method of claim 6,
The roller support part,
It further includes a pair of shaft support ribs extending from the bottom surface of the seating plate corresponding to the left edge and the right edge of the roller shaft accommodating hole to support the roller shaft,
The pair of shaft support ribs, Laundry treatment apparatus, characterized in that formed in front and rear of the roller receiving hole, respectively. delete cabinet;
a drum accommodated inside the cabinet;
a tub for accommodating the drum; and
and a dynamic absorber provided to absorb the vibration of the cabinet;
The dynamic absorber,
a support plate coupled to the cabinet;
a mass movably placed on the support plate to absorb vibration transmitted to the cabinet;
a supporter disposed between the mass body and the support plate, the supporter being in line or point contact with the mass body so that the mass body has a low damping ratio; and
In the moving direction of the mass, one or more elastic dampers are respectively disposed on both side ends of the mass,
The elastic damper is
a side support part in close contact with the side surface of the mass body;
and a bottom support part extending horizontally from the side support part to support a bottom surface of the mass body. 13. The method of claim 1 or 12,
A plurality of the supporters are provided,
The plurality of supporters are laundry treatment apparatus, characterized in that arranged on the same line in the width direction of the cabinet. cabinet;
a drum accommodated inside the cabinet;
a tub for accommodating the drum; and
and a dynamic absorber provided to absorb the vibration of the cabinet;
The dynamic absorber,
a support plate coupled to the cabinet;
a mass movably placed on the support plate to absorb vibration transmitted to the cabinet;
a supporter placed between the mass body and the support plate to support the mass body in line or point contact with a bottom surface of the mass body;
an additional mass placed on the support plate and spaced apart from the mass body in a direction crossing the movement direction of the mass body; and
and a slider disposed between the additional mass and the support plate and having damping due to frictional force. 15. The method of claim 14,
In the direction of movement of the additional mass, the laundry treatment apparatus further comprising an additional elastic damper placed on both side ends of the additional mass. 15. The method of claim 14,
The slider is
an upper slider mounted on the mass body;
a lower slider mounted on the support plate;
The upper slider is seated on the lower slider, the laundry treatment apparatus, characterized in that the friction movement. 15. The method of claim 14,
The mass of the mass body is a laundry treatment apparatus, characterized in that greater than the mass of the additional mass. 18. The method of claim 17,
The mass absorbs normal vibrations generated when the drum rotates at a first rotational speed,
The additional mass absorbs transient vibrations that occur when the drum rotates at a second rotational speed,
The first rotation speed is faster than the second rotation speed,
The vibration displacement of the normal vibration is smaller than the vibration displacement of the transient vibration.

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