[0001] The present invention relates to members for washing machines for reducing vibration.
More particularly a washing machine with reduced vibration during operation.
[0002] The washing machine removes contaminants from laundry by applying energy such by
impact using, for example, a pulsator, a rotating drum or an agitator. The drum washing
machine rotates a drum to drop the laundry to create an impact. The pulsator, or the
agitator washing machine creates an impact by means of a rotating pulsator or agitator
connected to a shaft vertically mounted in a washing tub.
[0003] Thus washing machines wash laundry by impacting the laundry mostly with mechanical
means. This causes in general vibration. To address this, washing machines are provided
with different vibration attenuation means.
[0004] Before starting description of a related art vibration attenuating method, as an
example of a related art washing machine, the drum washing machine will be described
with reference to FIGS. 1 and 2.
[0005] A cabinet 3, a body of the washing machine, is provided with a front portion 34,
side portions 32, an upper cover 38, and a lower base 36. The front portion 34 of
the cabinet has a door 4 mounted to be opened/closed, and the base 36 has legs 5 for
supporting the washing machine on a floor on which the washing machine is installed.
[0006] The cabinet 3 has a tub 7 for holding washing water, and a drum 9 rotatably mounted
therein for laundry. The drum 9 has a motor 11 connected to it for generating a driving
force to rotate the drum 9.
[0007] Upon putting the washing machine into operation, the drum 9 rotates at a high speed,
according to which vibration is occurs. Particularly, since the drum 9 rotates at
a high speed in a spinning cycle, the vibration is pronounced. According to this,
different kinds of means are provided to the washing machine for reducing the vibration
produced or to attenuate the generated vibration.
[0008] For example, for preventing and reducing transmission of the vibration from the drum
9 to the cabinet 3, and the like, there are springs 13 between the tub 7 and the upper
cover 38, and dampers 15 between the tub 7 and the base 36. Moreover, the material
or thickness of the side portions 32 and/or base 36 of the cabinet 3 are chosen, or
recesses 32a can be formed in the side portions 32 of the cabinet 3. As illustrated
in FIG 3 in detail, a leg pad 17 of a vibration absorbing material can be fitted to
the leg 5.
[0009] However, the related art vibration attenuating methods and washing machines have
the following problems.
[0010] First, any correlation between the different kinds of vibration attenuating means
has not been clear. This limits the reduction of vibration overall.
[0011] Second, effective attenuation of the vibration over all ranges of rotating speed
of the drum or the motor of the washing machine has been difficult. For an example,
if the damping properties of the dampers are designed for attenuation of transient
vibration mostly caused by non-uniform distribution of the laundry when commencing
a spinning cycle, the vibration can actually become heavier at the rated spinning
speed. Conversely, if the damping properties are designed differently, transient vibration
occurs if the vibration at the rated spinning speed is reduced. Moreover, in the case
of the leg pad, since the range of the rotation speed of the washing machine effective
for attenuating the vibration is fixed substantially depending on the material of
the leg pad, it is difficult to attenuate vibration effectively over all ranges of
rotation speed of the washing machine.
[0012] An aspect of the present invention is defined in the accompanying independent claims.
Some preferred features are recited in the dependent claims.
[0013] An embodiment of the present invention is directed to a washing machine that substantially
obviates one or more of the problems due to limitations and disadvantages of the related
art.
[0014] An object of embodiments of the present invention is to provide effective attenuation
of vibration in a washing machine.
[0015] Another object of embodiments of the present invention is to provide effective attenuation
of vibration of a washing machine in which vibration attenuation is effective over
a broad range of rotation speeds of the washing machine.
[0016] Additional features and advantages of the invention will be set forth in the description
which follows, and in part will be apparent to those having ordinary skill in the
art upon examination of the following or may be learned from practice of the invention.
The objectives and other advantages of the invention will be realized and attained
by the structure particularly pointed out in the written description and claims hereof
as well as the appended drawings.
[0017] To achieve these objects and other advantages and in accordance with the purpose
of the present invention, as embodied and broadly described herein, the washing machine
may include a cabinet forming an outside shape of the washing machine, legs fitted
to a bottom of the cabinet for supporting the cabinet, and leg pads joined to an underside
of the legs respectively for attenuating vibration occurring when the washing machine
is operated, wherein the leg pad is formed of block copolymer of hard blocks and soft
blocks.
[0018] The leg pad includes a first member in contact with a floor having the washing machine
installed thereon, and a second member in contact with the first member, wherein,
preferably, at least one of the first member and the second member is the block copolymer
of hard blocks and soft blocks.
[0019] Preferably, the hard block is a material which has required mechanical properties,
and the soft block is a material which has vibration attenuation characteristics.
Preferably, the soft block has a glass transition temperature of room temperature,
and more preferably, -30°C ∼ 30°C.
[0020] Preferably, the leg pad of the washing machine installed on a slippery floor has
a Shore hardness of approx. 80, and preferably the leg pad of the washing machine
installed on a non-slippery floor has a Shore hardness of approx. 30.
[0021] Preferably, the hard block is polystyrene, and the soft block is polyisoprene, and
more preferably, the soft block is vinyl-polyisoprene. The block copolymer is preferably
blended with at least one selected from olefin based thermo plastic resin, ethylene-α
olefin copolymer, ethylene-vinylacetate copolymer, ethylene-ethylacrylrate copolymer,
styrene-butadiene-styrene copolymer, and styrene-isoprene-styrene copolymer.
[0022] In other embodiment of the present invention, there is provided a washing machine
including a cabinet forming an outside shape of the washing machine, a tub in the
cabinet for holding washing water, a drum rotatably mounted in the tub, dampers fitted
between a base of the cabinet and the tub for reducing transmission of vibration from
the drum, wherein the damper is coupled to the cabinet, with a first damping member
in contact with the damper, and a second damping member in contact with the first
damping member placed inbetween, and at least one of the first damping member, and
the second damping member is block copolymer of hard blocks and soft blocks.
[0023] Also, the hard block is a material which has required mechanical properties, and
the soft block is a material which has vibration attenuation characteristics.
[0024] It is to be understood that both the foregoing description and the following detailed
description of the present invention are exemplary and explanatory and are intended
to provide further explanation of the invention claimed.
[0025] The accompanying drawings, which are included to provide a further understanding
of the invention and are incorporated in and constitute a part of this application,
illustrate embodiment(s) of the invention and together with the description serve
to explain the principle of the invention.
[0026] In the drawings;
FIG. 1 illustrates a perspective view of a related art drum washing machine;
FIG. 2 illustrates a longitudinal section of FIG. 1;
FIG. 3 illustrates a side view of the leg in FIG. 1;
FIGS. 4 and 5 illustrate graphs each showing a principle and effect of a washing machine
with reduced vibration in accordance with a preferred embodiment of the present invention;
FIG. 6 illustrates a structure of a leg pad applicable to a washing machine with reduced
vibration in accordance with a preferred embodiment of the present invention, schematically;
FIG. 7 illustrates a comparative graph of damping forces of the leg pads of the present
invention and the related art;
FIG. 8 illustrates a disassembled perspective view of a leg and a leg pad in accordance
with a preferred embodiment of the present invention;
FIG. 9 illustrates a side view of FIG. 8;
FIG. 10 illustrates a section of a leg and a leg pad in accordance with another preferred
embodiment of the present invention;
FIG. 11 illustrates a section of a leg and a leg pad in accordance with still another
preferred embodiment of the present invention;
FIG. 12 illustrates a section of a leg pad in accordance with another preferred embodiment
of the present invention;
FIG. 13 illustrates a section of a variation of FIG. 12;
FIGS. 14A and 14B illustrate a section and a plan view of a leg pad in accordance
with another preferred embodiment of the present invention, respectively;
FIGS. 15A and 15B illustrate a section and a plan view of a variation of FIGS. 14A
or 14B;
FIGS. 16 and 17 illustrate sections each showing a leg pad in accordance with another
preferred embodiment of the present invention; and
FIGS. 18 ∼ 21 illustrate sections each showing a detail of a damper fastening portion
in a washing machine with reduced vibration of the present invention.
[0027] A principle of a washing machine with a reduced vibration will be described, with
reference to FIGS. 4 and 5.
[0028] Of various methods for attenuating vibration, the inventor has searched the most
effective methods. As a result, of various approaches, such as dampers, material,
thickness and shape of the cabinet, and material of the leg pad, it turns out that
optimization of the leg pad is the most effective for reduction of the vibration.
Test results verifying that proper design of the leg pad is the most effective for
reduction of the vibration are illustrated in FIGS. 4 and 5.
[0029] FIGS. 4 and 5 illustrate graphs each showing principle and effect of a washing machine
with reduced vibration in accordance with a preferred embodiment of the present invention.
That is, vibrations of different washing machines (hereafter called "samples"), in
which various parameters generally known to be effective for vibration are varied,
are measured in spinning processes in which vibration can cause the most serious problem.
In the vibration measurement, a 400g of eccentricity is provided, and the vibration
is measured at a right side upper comer 'A' and at a right side central portion 'B'
of the cabinet with a vibration measuring apparatus (EQP/2).
[0030] FIG. 4 illustrates the test result the a right side portion of the cabinet, and FIG.
5 illustrates a test result at a left side portion of the cabinet. In FIGS. 4 and
5, A(Max) denotes a greatest vibration measured at the upper comer, and A(Normal)
denotes a normal vibration measured at the upper comer. Likewise, B(Max) denotes a
greatest vibration measured at the central portion, and B(Normal) denotes a normal
vibration measured at the central portion.
[0031] Sample 1 denotes a drum washing machine in which a 0.15mm bead depth is added to
a general bead depth formed at the side of the cabinet, and the leg pad is formed
of butyl rubber as in the related art. Sample 1a denotes the same washing machine
as sample 1, except that the material of the leg pad is different. Sample 2 denotes
a drum washing machine in which bead depth is not changed, and material of the leg
pad is also the butyl rubber. Sample 2a denotes a washing machine the same as sample
2, except that the material of the leg pad is different.
[0032] The material for the leg pad used in sample 1a and sample 2a, showed to the invention
that the best result is obtained from among many materials studied and tested.
[0033] Upon reviewing test results of sample 1 and sample 2 with leg pads that are the same,
and only the bead depths are different, it was noted that deeper bead depth is effective
for attenuation of vibration to some extent. However, it was observed that the correlation
between the bead depth and the vibration attenuation is not clear.
[0034] However, upon reviewing test results of sample 1 and sample 1a, or sample 2 and sample
2a, in which bead depths are the same, and the leg pads are different, it was noted
that a proper leg pad is very effective for attenuating vibration.
[0035] Moreover, upon reviewing test results of sample 1a and sample 2a, it was noted that
optimization of the material of the leg pad is more effective for vibration attenuation
than the bead depth.
[0036] Therefore, for effective vibration attenuation, it is particularly preferable that
the leg pad is designed properly. Therefore, it is preferable that, first of all,
the most suitable leg pad, particularly, the most suitable material of the leg pad
is used for attenuation of the vibration, and the other vibration attenuation parameters
are taken into consideration. According to this, the inventor further studied which
the leg pad would be most suitable for vibration attenuation.
[0037] First of all, it is required that the leg pad has an excellent vibration attenuating
characteristic. However, for use as the leg pad it is required necessary for it to
meet other conditions. For an example, its mechanical properties, such as hardness,
its anti-slip property for preventing the washing machine from moving from an installed
place, its formability for ease of fabrication, and the like have to be considered.
Because, even if the vibration attenuation characteristic is satisfied, if the material
fails to have a proper hardness, resonance can occur at a certain range of rotation
speed of the washing machine, to cause the washing machine to 'walk' across the floor.
If friction with the floor is not adequate, it is liable that the washing machine
will move too easily across the floor.
[0038] At the end, even though it is required that the leg pad meets these other conditions
in addition to the vibration attenuating characteristic, selection of an optimal leg
pad has notproved possible up to now. Accordingly, up to now, as the leg pad, metal,
plastic, isobutylene-isoprene rubber, or the like is used, each material has advantages,
and disadvantages. Even though metal or plastic, with a comparatively high hardness,
has a resonance range outside of the typical rotation speed of the washing machine,
it is liable that the leg pad of metal or plastic causes walking of washing machine
in almost all ranges of the rotation speed, regardless of the rotation speed. Moreover,
the leg pad of metal or plastic is liable to cause slipping of the washing machine
because the metal or plastic has low frictional engagement with the floor. In the
case of the butyl rubber, since the butyl rubber has a resonance range coincident
with a low rotation speed range of the washing machine, it is required that the washing
machine is better to pass this resonance range quickly. Also, the leg pad of butyl
rubber is liable to cause walking of the washing machine in the low rotation speed
range, even though the walking is comparatively rare at high rotation speeds.
[0039] The inventor has found that use of a block copolymer of hard blocks and soft blocks
is surprisingly very effective as the material of the leg pad. That is, as illustrated
in FIG 6, the inventor has found that the leg pad is preferably formed of a copolymer
in which the hard blocks HS and the soft blocks SS make a net form. Because the use
of the leg pad of the copolymer of the hard blocks HS and the soft blocks SS enables
selection of a material that meets required mechanical properties, such as hardness,
i.e. the hard blocks, and a material that meets required vibration attenuation characteristic,
i.e the soft blocks. According to this, the leg pad can be designed comparatively
easily to meet the vibration attenuation characteristics while other conditions are
also met.
[0040] In view of vibration attenuation, it is preferable that a material that has a glass
transition is used as the block copolymer, particularly, the soft block. A material
of which the glass transition temperature is close to a temperature at which the washing
machine is used is better still. While thermal movement in chain forms of polymers
in the net becomes violent at higher temperatures than the glass transition temperature,
creating a rubbery state, the thermal movement is suppressed at temperatures below
the glass transition temperature, and it then becomes glassy due to reduction of its
own volume, and has poor vibration attenuation qualities.
[0041] Since amorphous polymers, such as rubber, exhibit the glass transition, it is preferable
that rubber is selected as the leg pad. The butyl rubber used presently also exhibits
the glass transition. However, as described before, the leg pad is required to have
other properties which the butyl rubber, in the form of a copolymer prepared by copolymerizing
a small amount of isoprene with isobutylen, cannot meet. In view of the vibration
attenuation characteristic, it is difficult to obtain the desired adequate vibration
attenuation effect because the butyl rubber has a glass transition temperature in
the range of -40°C∼ -60°C, which is substantially lower than the temperature of use
of the washing machine. As shown in FIG 7, in the case of butyl rubber, though the
butyl rubber has a uniform damping force in a broad temperature range in which the
washing machine is used in a more realistic temperature range of use of the washing
machine, the damping force of the leg pad of the butyl rubber is poorer than the leg
pad of the block copolymer.
[0042] As described, preferably, the leg pad of the present invention is formed of a block
copolymer of hard blocks and soft blocks, wherein the hard blocks are selected with
mechanical considerations in mind, and the soft blocks are selected with vibration
attenuation in mind.
[0043] Accordingly, it is preferable that a material is selected as the soft block, of which
the glass transition temperature is in the vicinity of the temperature of use of the
washing machine. Of course, it is preferable that a material is selected for the hard
blocks in view of requirements of mechanical properties, such as hardness. For an
example, in the case of a washing machine installed on a slippery floor of cement
or tile, it is preferable that the hardness of the leg pad is high. In general, it
is preferable that the Shore hardness is approx. 80. In contrast to this, in the case
of wood flooring, it is preferable that the hardness is low, in general, approx. 30
in Shore A hardness.
[0044] As a result of tests on various materials, the inventor has found that the hard block
can be polystyrene, and the soft block can be polyisoprene, particularly, vinyl-polyisoprene.
[0045] In fabrication of the leg pad, though the block copolymer may be used solely, at
least one selected from olefin based thermo plastic resin, ethylene-α olefin copolymer,
ethylene-vinylacetate copolymer, ethylene-ethylacrylrate copolymer, styrene-butadiene-styrene
copolymer, and styrene-isoprene-styrene copolymer may be blended with the block copolymer.
Moreover, additives, such as a cross-linker, filler, and/or softener may be introduced
into a base material of the block copolymer, that is known to a person skilled in
the field of art, of which detailed description will be omitted.
[0046] As described, the leg pad of the block copolymer of hard block and soft block enables
fabrication of a leg pad that satisfies the vibration attenuation characteristic and
other required properties very well.
[0047] In order to verify this, a test was carried out on a material that substantially
satisfies the above conditions among commercially available materials. The material
used in the test is Kuraray Hybrar. The Hybrar, a block copolymer of polystyrene and
polyisoprene, has a glass transition temperature in the vicinity of room temperature
of approx. -19°C ∼ -8°C. As shown in FIG. 7, it is verified that the leg pad of the
Hybrar has very good damping properties in the vicinity of room temperature. In FIG
4 or 5, the material of the leg pad in the sample 1a and the sample 2a is Hybrar.
Of course, the material suitable for the leg pad is not limited to Hybrar, and any
material that satisfies above conditions can be used.
[0048] It is also preferable that the leg pad has, not only an excellent vibration attenuation
characteristic, but also excellent formability and workability for the sake of the
production costs of the washing machine. Hybrar has a better anti-slip characteristic
than butyl rubber, and particularly, maintains good friction even in a watery environment
compared to other rubbers. Moreover, since the Hybrar can be used as a thermoplastic
resin that can be injection molded or extrusion molded, or a thermosetting resin that
can be pressed, the Hybrar also has the advantage of good formability. However, if
it is intended to use the Hybrar as the thermosetting resin, a separate cross-linker
is required.
[0049] Referring to FIG 8, an embodiment is shown in which the leg is joined to the leg
pad by a predetermined method. In general, the leg 5 includes a cylindrical body 52,
and a hexagonal head 54 at a bottom end of the body 52. It is preferable that the
body 52 has an external thread for easy height adjustment. The head 54 is used for
easy turning of the body 52 for adjustment of the height.
[0050] The leg pad 17 is fitted to a bottom end of the leg 5. Though the leg pad 17 may
be fitted to the head 54 of the leg 5 directly, it is preferable that an enlarged
base portion 56 may be further formed in a lower portion of the head 54 forming a
fitting area for easy fitting.
[0051] The leg 5 and the leg pad 17 may be joined by insert molding, bonding, or other methods.
For an example, as shown in FIG. 9, the leg 5 and the leg pad 17 may be joined with
an adhesive. As shown in FIG 10, the leg 5 and the leg pad 17 may be joined by insert
molding. As shown in FIG 11, a recess 17a having part of a lower portion of the leg
pad 17 cut away therefrom in a circumferential direction may be formed, and the leg
5 and the leg pad 17 may be joined with an annular resilient clip 19 that embraces
the enlarged portion 56 of the leg and the recess 17a in the leg pad 17.
[0052] In the meantime, though a leg pad formed of one material, i.e., the block copolymer
is described in the above embodiment, as a result of study, the inventor has found
that it is possible to form the leg pad of more than two materials. That is, it is
preferable that the leg pad is formed of a first member in contact with a floor and
a second member in contact with the first member. One of the first and second members
can be formed of block copolymer, and the other one formed in other material, such
as butyl rubber. Because the material of the leg pad, i.e., the block copolymer for
the hard blocks, and the soft blocks may undergo plastic deformation over time, degradation
vibration attenuation can result. Particularly, the vibration attenuation effect can
become poor in the low temperature range.
[0053] Referring to FIG. 12, the leg pad 17 includes a first member 17a in contact with
a floor having the washing machine installed thereon, and a second member 17b fitted
to the first member 17a, wherein it is preferable that one of the first member 17a
and the second member 17b is formed of butyl rubber, and the other one is formed of
block copolymer. For the sake of description, the cross hatching (for an example,
reference symbol 17b in FIG. 12) denote that the material is block copolymer, and
the dots (for an example, reference symbol 17a in FIG. 12) denotes that the material
is butyl rubber.
[0054] Though the first member 17a may be formed of butyl rubber, and the second member
17b may be formed of block copolymer, as shown in FIG. 13, the first member 17a can
be formed of block copolymer, and the second member 17b can be formed of butyl rubber.
Because the block copolymer has better contact with the floor, it is favorable that
the first member 17a is formed of the block copolymer.
[0055] Referring to FIGS. 14A and 14B, the first member 17a may have a projection 170 having
the second member 17b passing through it. Or, as shown in FIGS. 15A and 15B, the first
member 17a may have a plurality of projections 170 having the second member 17b passing
through them.
[0056] Referring to FIGS. 16 and 17, a third member 17c of the same material as the first
member 17a may be fitted to top of the second member 17b.
[0057] The first member 17a, the second member 17b, and the third member 17c may be joined
by bonding, or double injection molding, and the leg pad 17 and the leg may be joined
by bonding, insert molding, or mechanical joining, as described before.
[0058] In the study made by the inventor, it turns out that the principle of the present
invention is applicable not only to the leg, but also to other components, used in
the washing machine and the like as a vibration attenuator. Particularly, it is preferable
that the principle of the present invention is applied to the damper fitted between
the base of the cabinet and the tub for preventing vibration of the washing machine
and the like being transmitted to the cabinet.
[0059] The application of the principle of the present invention to the damper of the drum
washing machine will be described with reference to FIG. 18.
[0060] One end of the damper 15 is fixed to the base 36 with a damping member 100 placed
in between. In this instance, though the damping member 100 may be formed of one material
solely, i.e., the block copolymer, as a result of study of the inventor, it is found
out that it is possible to form the damping member 100 of the present invention of
more than two materials. For an example, one is formed of block copolymer, and the
other one is formed of other material, such as butyl rubber. The block copolymer of
the hard blocks, and the soft blocks may undergo plastic deformation after a certain
time period, resulting in poor vibration attenuation. Particularly, the vibration
attenuation effect can become poor in a low temperature range.
[0061] For the sake of description, cross hatching (for an example, reference symbol 120
in FIGS. 18 ∼ 21) denotes that the material is block copolymer, and the dot marks
on the section (for an example, a reference symbol 110 in FIGS. 18 ∼ 21) denote that
the material is butyl rubber.
[0062] Referring to FIG 18, the damper 15 is fixed to the base 36 with a first damping member
110 in contact with the damper 15. A second damping member 120 is in contact with
the first damping member 110 placed inbetween, wherein one of the first damping member
110 and the second damping member 120 is a block copolymer of hard blocks and soft
blocks.
[0063] In more detail, the damper 15 has a hollow coupling portion 15a at one end (the portion
nearest to the base of cabinet). The coupling portion 15a has a cylindrical first
damping member 110 fitted therein, and a cylindrical second damping member 120 is
fitted in the hollow of the first damping member 110. There is a bracket 16 fixed
to the base 36, having one side open to receive the damper.
[0064] The coupling portion 15a of the damper 15, the first damping member 110, and the
second damping member 120 are positioned in the opening of the bracket 16, and, in
this arrangement, a bolt 16a is passed through the bracket 16, and the second damping
member 120, so that the damper 15 is fitted between the tub and the cabinet.
[0065] Referring to FIG 18, the first damping member 110 may be formed of butyl rubber,
and the second damping member 120 formed of block copolymer. However, as shown in
FIG 19, it is preferable that the first damping member 110 is formed of the block
copolymer, and the second damping member 120 is formed of butyl rubber. This is because
it is favorable in view of vibration attenuation that the first damping member 110
that comes into contact with the damper 15 at first is formed of the block copolymer.
[0066] Moreover, referring to FIGS. 20 and 21, it may also possible that a third damping
member 130, formed of the same material as the material of the first damping member
110, is fitted on an inside of the second damping member 120. Of course, it is also
possible that the third damping member 130 is fitted on an outside of the first damping
member 110.
[0067] Besides the first damping member 110, the second damping member 120, and the third
damping member 130 being joined by bonding or double injection molding, the components
may alternatively be joined by other methods.
[0068] Though a drum washing machine is illustrated and described in the above embodiments,
the present invention is not limited to this. That is, the present invention is applicable
to the pulsator washing machine, and the agitator washing machine, too. Moreover,
the present invention is applicable, not only to a leg joined to the cabinet, but
also to other components that are used for attenuation of vibration in the washing
machine.
[0069] It will be apparent to those skilled in the art that various modifications and variations
can be made in the present invention without departing from the spirit or scope of
the invention. Thus, it is intended that the present invention cover the modifications
and variations of this invention provided they come within the scope of the appended
claims and their equivalents.
[0070] As has been described, the method for attenuating vibration of a washing machine,
and a washing machine thereof has the following advantages.
[0071] First, vibration can be attenuated effectively by selecting the leg pads, properly.
That is, vibration of the washing machine can be reduced effectively while changes
in design, and cabinet material, thickness, and bead depth that raise production costs
increases are minimized. That is, by proper selection of the damping member of the
damper, and the leg pad of which design and effect verification are comparatively
easy, the vibration can be attenuated very effectively.
[0072] Second, the present invention permits selection of a leg pad which meets, not only
the vibration attenuation characteristic, but also other necessary properties, such
as hardness, and anti-slip characteristics. At the same time, the invention can make
a washing machine design effective in vibration attenuation over all ranges of rotation
speed of the washing machine.
1. A washing machine comprising:
a cabinet forming an outside shape of the washing machine;
supports fitted to the cabinet; and
a support pad joined to an underside of the leg for attenuating vibration when the
washing machine is operated,
wherein the support pad is formed of block copolymer of hard blocks and soft blocks.
2. The washing machine as claimed in claim 1, wherein the pad includes;
a first member for contacting a floor and
a second member in contact with the first member,
wherein at least one of the first member and the second member is the block copolymer
of hard blocks and soft blocks.
3. The washing machine as claimed in claim 1 or 2, wherein the hard block is a material
which has suitable mechanical properties, and the soft block is a material which has
vibration attenuation properties.
4. The washing machine as claimed in claim 1, 2 or 3, wherein the soft block has a glass
transition temperature at room temperature.
5. The washing machine as claimed in claim 4, wherein the glass transition temperature
is -30°C ∼ 30°C.
6. The washing machine as claimed in claim 3, wherein the pad of the washing machine
has a Shore hardness of approx. 80.
7. The washing machine as claimed in claim 3, wherein the pad of the washing machine
has a Shore hardness of approx. 30.
8. The washing machine as claimed in claim 1, 2 or 3, wherein the hard block is polystyrene,
and the soft block is polyisoprene.
9. The washing machine as claimed in claim 1, 2 or 3, wherein the soft block is vinyl-polyisoprene.
10. The washing machine as claimed in claim 9, wherein the block copolymer is blended
with at least one selected from olefin based thermo plastic resin, ethylene-α olefin
copolymer, ethylene-vinylacetate copolymer, ethylene-ethylacrylrate copolymer, styrene-butadiene-styrene
copolymer, and styrene-isoprene-styrene copolymer.
11. The washing machine as claimed in claim 3, wherein the support and the pad are joined
by being bonded with an adhesive, by insert molding, or by a resilient clip.
12. The washing machine as claimed in claim 2, wherein the first member has at least one
projection projecting into the second member.
13. The washing machine as claimed in claim 2, wherein the second member has a third member
in contact therewith, made of the same material as the first member.
14. A washing machine comprising:
a cabinet;
a tub in the cabinet for holding washing water; and
dampers fitted between a base of the cabinet and the tub for reducing transmission
of vibration from the drum,
wherein the damper is coupled to the cabinet, a first damping member being in
contact with the damper, and a second damping member being in contact with the first
damping member placed inbetween, at least one of the first damping member and the
second damping member being block copolymer of hard blocks and soft blocks.
15. The washing machine as claimed in claim 14, wherein the second damping member has
a third damping member in contact therewith, made of the same material as the first
damping member.
16. The washing machine as claimed in claim 14 or 15, wherein the hard block is a material
which has suitable mechanical properties, and the soft block is a material which has
vibration attenuation properties.
17. The washing machine as claimed in claim 16, wherein the soft block has a glass transition
temperature at room temperature.
18. The washing machine as claimed in claim 17, wherein the glass transition temperature
is -30°C ∼ 30°C.
19. The washing machine as claimed in claim 16, wherein the hard block is polystyrene,
and the soft block is polyisoprene, for example vinyl-polyisoprene.
20. The washing machine as claimed in claim 19, wherein the block copolymer is blended
with at least one selected from olefin based thermo plastic resin, ethylene-α olefin
copolymer, ethylene-vinylacetate copolymer, ethylene-ethylacrylrate copolymer, styrene-butadiene-styrene
copolymer, and styrene-isoprene-styrene copolymer.
21. A vibration attenuating member for a washing machine comprising a block copolymer
of hard blocks and soft blocks, the member being, for example, a support or a damper.