Damper and washer comprising same

Abstract

A damper and a washer according to the present disclosure comprise: a case having an accommodation space formed therein; a load comprising an internal part located in the accommodation space of the case and an external part located outside the case, and installed so as to move relative to the case; a disc coupled to the internal part of the load; a coil installed on the outer circumference of the internal part of the load; and a fluid accommodated in the accommodation space and having a viscosity that varies depending on a variation in a magnetic field generated by the coil.

Description

Damper and washing machine including same

[0001] The present disclosure relates to a damper, and more particularly, to a damper that provides damping force corresponding to various conditions.

[0002] In a conventional washing machine (patent document 1), a tub is installed inside an outer case forming the exterior with a friction damper and a buffer spring as a medium, and a drum capable of holding laundry is accommodated inside this tub. In addition, this drum is installed at the bottom and is installed to be rotatable with a motor and a belt installed to rotate according to the power supply by a power cord.

[0003] That is, when the motor rotates, the belt rotates synchronously and transmits rotational power to a pulley fixed to the rotational axis of the drum, so that the rotational power of the motor is transmitted to the drum.

[0004] Therefore, after power is supplied to the above motor and the control unit is operated to enter the dehydration cycle of the drum washing machine, the motor, which is the driving source, begins to rotate and rotates the drum installed in the tub via a belt.

[0005] At this time, the tub vibrates up, down, left, and right due to the centrifugal force acting on it due to the unbalanced mass generated by the laundry inside the drum.

[0006] That is, the motion applied to the above tub is transmitted to the lower part of the outer case and is damped by the friction damper installed at the lower part.

[0007] However, since the conventional friction damper only provides a constant damping force, when centrifugal force is generated due to the unbalanced mass during dehydration, a large vibration occurs in the transient state where the vibration of the tub passes the natural frequency, and even when the steady-state rotation speed is reached, vibration displacement occurs due to eccentricity, but the friction damper has a problem in that the characteristics of the damper do not change according to these conditions, resulting in a large vibration.

[0008] Patent Document 2 describes a friction damper. Specifically, the damper (70) is configured to include a piston mechanism (80) connected to the drum-side damper bracket (61), a cylinder mechanism (90) connected to the base-side damper bracket (62), a friction member (74) fixed to one of the piston mechanism (80) and the cylinder mechanism (90) to generate friction due to relative motion, and an elastic member (76) providing elasticity to the piston mechanism (80).

[0009] In the case of Patent Document 2, there is also a problem in that the damper provides constant friction and elasticity, and thus the transient vibration of the tub cannot be effectively attenuated.

[0010] [Prior Art Literature]

[0011] [Patent Document]

[0012] Patent Document 1 - Korean Publication No. 2006-0120918

[0013] Patent Document 2 - Korean Publication No. 2005-0043171

[0014]

[0015] The problem to be solved by the present disclosure is to provide a damper capable of simultaneously reducing transient and steady-state vibrations by changing the damping value by varying the characteristics of a magnetorheological fluid according to a change in a magnetic field, and a washing machine including the damper.

[0016] The problem to be solved by the present disclosure is to provide a damper and a washing machine including the damper, which has a very high yield stress, is resistant to impurities, and has current control, so that a high-voltage device is not required.

[0017] The problem to be solved by the present disclosure is to provide a damper having a simple structure, easy to manufacture, and low manufacturing cost, and a washing machine including the damper.

[0018] The tasks of the present disclosure are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

[0019]

[0020] The damper according to the present disclosure for solving the above-described problem is characterized in that it adjusts the damping force by changing the magnetic field applied to the fluid contained inside the case.

[0021] Specifically, a damper according to the present disclosure comprises a case having an accommodation space therein, an inner part positioned in the accommodation space of the case, and an outer part positioned outside the case, and is characterized by including a rod installed to move relative to the case, a disc coupled to the inner part of the rod, a coil installed on the outer periphery of the inner part of the rod, and a fluid accommodated in the accommodation space and having a viscosity that changes according to a change in a magnetic field generated by the coil.

[0022] A flow gap through which the fluid flows can be defined between the above disk and the case.

[0023] The above disk may include a first disk and a second disk spaced apart from the first disk in the longitudinal direction of the load.

[0024] The coil may be positioned between the first disk and the second disk.

[0025] The case may include a mid member formed to surround the inner portion, an upper member coupled to an upper end of the mid member and including an upper through hole through which the load passes, and a lower member coupled to a lower end of the mid member.

[0026] The above case may further include an arm connected to one end of the lower member.

[0027] A load space can be formed inside the above arm to accommodate a portion of the load.

[0028] The above lower member may further include a lower through hole through which the load passes.

[0029] The above disk and the above mid member are circular when viewed in the longitudinal direction of the above load and can share one center.

[0030] The above disk may further include a plurality of protrusions protruding radially from the outer periphery.

[0031] The outer surface of the above disc may be sawtoothed or wavy.

[0032] The above mid member is circular when viewed in the longitudinal direction of the above load, and the distance between the outer circumference of the above disc and the inner circumference of the above mid member can be periodically changed along the outer circumference of the above disc.

[0033] The above load may further include a load recessed portion that is recessed inward from the outer surface of the load.

[0034] The above load depressions may be arranged in multiple numbers spaced apart in the first direction.

[0035] The above load depression may have a ring shape when viewed in the first direction.

[0036] According to one embodiment of the present disclosure, a washing machine includes a casing, a tub installed inside the casing and containing washing water therein, a drum rotatably installed inside the tub, and a damper supporting the tub within the casing and providing a damping force, wherein the damper includes a case having a receiving space therein, an inner part positioned in the receiving space of the case, and an outer part positioned outside the case, and is characterized in that it includes a rod installed to move relative to the case, a disc coupled to the inner part of the rod, a coil installed on the outer periphery of the inner part of the rod, and a fluid contained in the receiving space, the viscosity of which changes according to a change in a magnetic field generated by the coil.

[0037] The above load of the above damper can be fastened to the above tub, and one end of the above case of the above damper can be fastened to the above casing.

[0038] Additionally, the present disclosure may further include an elastic member supporting the tub to the casing.

[0039] The elastic member may be positioned above the center of rotation of the drum, and the damper may be positioned below the center of rotation of the drum.

[0040]

[0041] The damper and washing machine of the present disclosure have one or more of the following effects.

[0042] First, the present disclosure has the advantage of simultaneously reducing transient and steady-state vibrations by changing the damping value by varying the characteristics of the magnetorheological fluid according to the change in the magnetic field.

[0043] Second, the present disclosure can provide a large damping force because it can greatly increase the viscosity of the magnetorheological fluid by supplying a small amount of current, resulting in a very large yield stress, and it has the advantage of being resistant to impurities because foreign substances from outside cannot easily enter the interior of the case.

[0044] Third, since the present disclosure supplies current to the coil inside the case through the space inside the load, the case is not opened, so impurities cannot enter from the outside, the power cable does not occupy the space in the case, and there is an advantage of less risk of short circuit.

[0045] Fourth, the present disclosure has the advantage of reducing the total length of the damper while improving the damping force of the damper by making the length of the rod longer than the length of the case, since a portion of the load is accommodated in the accommodation space of the arm.

[0046] In addition, the present disclosure has the advantage of being easy to manufacture due to its simple structure and having a low manufacturing cost.

[0047]

[0048] FIG. 1 is a side cross-sectional view illustrating the internal configuration of a washing machine according to one embodiment of the present disclosure.

[0049] FIG. 2 is a cross-sectional view illustrating the internal configuration of a washing machine according to one embodiment of the present disclosure.

[0050] FIG. 3 is a cross-sectional view of a damper according to an embodiment of the present disclosure.

[0051] Figure 4 is a cross-sectional view taken along the periphery of the disk illustrated in Figure 3 in a direction intersecting the axial direction.

[0052] FIG. 5 is a cross-sectional view of a disk periphery according to another embodiment of the present disclosure.

[0053] FIG. 6 is a cross-sectional view of a disk periphery according to another embodiment of the present disclosure.

[0054] FIG. 7a is a cross-sectional view of a rod according to another embodiment of the present disclosure.

[0055] Fig. 7b is a cross-sectional view of the load depression portion of the load illustrated in 7a.

[0056] Figure 8 is a control flowchart of a damper according to one embodiment of the present disclosure.

[0057] FIG. 9 is a graph showing a current control process according to the rotation speed of a washing machine according to one embodiment of the present disclosure.

[0058]

[0059] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the invention, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0060] Spatially relative terms such as "below," "beneath," "lower," "above," and "upper" can be used to easily describe the relationship between one component and another, as illustrated in the drawings. Spatially relative terms should be understood to include different orientations of the components during use or operation in addition to the orientations depicted in the drawings. For example, if a component depicted in the drawings were flipped over, a component described as "below" or "beneath" another component could be positioned "above" the other component. Thus, the exemplary term "below" can include both the above and below orientations. Components can also be oriented in other directions, and thus spatially relative terms can be interpreted based on their orientation.

[0061] The terminology used herein is for the purpose of describing embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular includes the plural unless specifically stated otherwise. As used herein, the terms "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components, steps, and / or operations.

[0062] Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used in their common sense to those of ordinary skill in the art to which this disclosure pertains. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0063] The thickness and size of each component in the drawings are exaggerated, omitted, or schematically illustrated for convenience and clarity. Furthermore, the size and area of ​​each component do not entirely reflect its actual size or area.

[0064] Additionally, the angles and directions mentioned in the process of describing the structure of the embodiment are based on those described in the drawings. If the reference points and positional relationships for angles are not clearly mentioned in the description of the structure forming the embodiment in the specification, the relevant drawings should be referenced.

[0065] The present disclosure will be described in detail with reference to the attached drawings.

[0066] FIG. 1 is a side cross-sectional view illustrating the internal configuration of a washing machine according to one embodiment of the present disclosure, and FIG. 2 is a front cross-sectional view illustrating the internal configuration of a washing machine according to one embodiment of the present disclosure.

[0067] Referring to FIGS. 1 and 2, in one embodiment of the present disclosure, a washing machine comprises a casing (2) forming the exterior of the washing machine, a tub (6) installed on the inside of the casing (2) by an elastic member (4) and a damper (100) and containing washing water therein, a drum (8) rotatably installed on the inside of the tub (6) and having a plurality of holes (7) formed therein for loading laundry and allowing washing water to flow in and out, a lifter (10) installed on the inner surface of the drum (8) to lift laundry loaded into the drum (8) and then drop it from a certain height, and a motor (12) installed on the rear side of the tub (6) to transmit power to the drum (8).

[0068] Here, the casing (2) includes a cabinet (22) forming the side and back of the washing machine, a base (24) forming the bottom of the washing machine, a top plate (26) coupled to the top of the cabinet (22) to form the upper surface of the washing machine, and a cabinet cover (28) mounted on the front of the cabinet (22) to form the front of the washing machine.

[0069] A control panel (14) that controls the operation of the washing machine or displays it to the user is placed between the cabinet cover (28) and the top plate (26), and a door (18) that opens and closes the laundry entrance (27) is rotatably installed on the front of the cabinet cover (28).

[0070] And, the upper part of the tub (6) is installed on the upper part of the cabinet (22) by a plurality of elastic members (4), and the lower part is supported so as to be cushioned on the upper surface of the base (24) by a plurality of dampers (100).

[0071] That is, the elastic member (4) is composed of a left elastic member (4A) whose lower end is connected to the upper left side of the tub (6) and whose upper end is connected to the upper left side of the cabinet (2), and a right elastic member (4B) whose lower end is connected to the upper right side of the tub (6) and whose upper end is connected to the upper right side of the cabinet (2).

[0072] Cabinet brackets (30) having upper hanging holes (31) for hanging the upper part of elastic members (5) are installed on the upper left and right sides of the cabinet (22), respectively, and spring connecting parts (32) having lower hanging holes (33) for hanging the lower part of elastic members (5) are formed on the upper left and right sides of the tub (6), respectively.

[0073] As the elastic member (4), a coil (140) spring having a certain elastic coefficient is used.

[0074] In addition, the damper (100) is composed of a left damper (100) (100A) whose upper end is connected to the lower left side of the tub (6) and whose lower end is connected to the upper left side of the base (24), and a right damper (100) (100B) whose upper end is connected to the lower right side of the tub (6) and whose lower end is connected to the upper right side of the base (24).

[0075] The damper (100) is connected to the damper connection portions (34) formed on the lower side of the tub (6) and the upper side of the base (24) by a damper pin (40). The damper connection portions (34) are formed on the lower left and right sides of the tub (6) and are composed of an upper damper connection portion (36) to which the upper side of the damper (100) is connected by a damper pin (40), and a lower damper connection portion (38) to which the lower side of the damper (100) is connected by a damper pin (40) and are formed on the upper left and right sides of the base (24).

[0076] The elastic member (4) may be positioned above the rotation center of the drum (8), and the damper (100) may be positioned below the rotation center of the drum (8).

[0077]

[0078] Hereinafter, the damper (100) of the present disclosure will be described in detail.

[0079] FIG. 3 is a cross-sectional view of a damper (100) according to one embodiment of the present disclosure.

[0080] Referring to FIG. 3, a damper (100) according to one embodiment of the present disclosure includes a case (110), a rod (120), a disk (130), a coil (140), and a fluid (190).

[0081] The case (110) has an accommodation space (A) therein. The accommodation space (A) accommodates a fluid (190) and a portion of the disk (130) and the rod (120). Here, the fluid (190) accommodated in the accommodation space (A) may include a magnetorheological fluid whose properties change according to a magnetic field generated from a coil (140). The magnetorheological fluid changes its viscosity according to a change in the magnetic field generated from the coil (140), thereby changing the frictional force between the fluid (190) and the rod (120) and the frictional force between the fluid (190) and the disk (130).

[0082] For example, a magnetorheological fluid is a dispersion of magnetic particles in a solvent.

[0083] The rod (120) is installed through the case (110), and the rod (120) can move relative to the case (110). That is, the rod (120) can reciprocate along the axial direction (Ax) in the case (110).

[0084] The case (110) may be manufactured in one piece, but may be manufactured in multiple pieces for ease of assembly.

[0085] For example, the case (110) may include a mid member (111), an upper member (112), and a lower member (115).

[0086] The mid member (111) may have an axially wrapping structure. For example, the mid member (111) may have a cylindrical shape with both ends in the axial direction (Ax) open and centered on the axis.

[0087] The upper member (112) is coupled to the upper end of the mid member (111) and closes the opening at the upper end of the mid member (111). The upper member (112) may include an upper through hole (112a) through which the rod (120) passes.

[0088] An upper sealing portion (161) may be installed in the upper member (112) to prevent fluid (190) from leaking out to the outside by a rod (120) passing through the upper through hole (112a). The upper sealing portion (161) may perform a function of scraping off fluid (190) stuck to the rod (120) like a scraper and a function of preventing fluid (190) inside the case (110) from being discharged to the outside.

[0089] For example, the upper member (112) may include a first upper member (113) that is fitted into the upper outer surface of the mid member (111), a space that accommodates an upper sealing portion (161) between the first upper member (113), and a second upper member (114) that is coupled with the first upper member (113).

[0090] The first upper member (113) and the second upper member (114) can be fastened to the upper screw (151).

[0091]

[0092] The lower member (115) is coupled to the lower end of the mid member (111) and closes the opening at the lower end of the mid member (111). The lower member (115) may completely close the lower opening of the mid member (111), or the lower member (115) may be formed with a lower penetration hole (115a) through which the rod (120) passes.

[0093] When the lower penetration hole (115a) is formed and the rod (120) passes through it, the area of ​​the rod (120) that rubs against the fluid (190) increases, thereby improving the damping force and yield stress of the damper (100).

[0094] A lower sealing portion (162) may be installed in the lower member (115) to prevent fluid (190) from leaking out to the outside by a rod (120) passing through the lower penetration hole (115a). The lower sealing portion (162) may perform a function of scraping off fluid (190) attached to the rod (120) like a scraper and a function of preventing fluid (190) inside the case (110) from being discharged to the outside.

[0095] For example, the lower member (115) may include a first lower member (116) that is fitted into the lower outer surface of the mid member (111), a space that accommodates a lower sealing portion (162) between the first lower member (116), and a second lower member (117) that is coupled with the first lower member (116).

[0096] The first lower member (116) and the second lower member (117) can be fastened to the lower screw (152).

[0097] The case (110) may further include an arm (118). The arm (118) connects the case (110) and the casing (2). Specifically, one end of the arm (118) is connected to the case (110), and the other end of the arm (118) is connected to the damper connection (34). More specifically, the other end of the arm (118) may be connected to the lower damper connection (38).

[0098] More specifically, the arm (118) is connected to the lower end of the lower member (115), and a pin hole (119) into which a damper pin (40) is inserted can be formed at the lower end of the arm (118).

[0099] A space for a load (120) can be formed inside the arm (118) to accommodate a portion of the load (120). The space for the load (120) can be positioned to overlap the lower through hole (115a) in the axial direction (Ax). The space for the load (120) prevents the load (120) protruding outside the case (110) from being visible from the outside, and reduces the length of the space through which the load (120) protrudes, thereby reducing the overall length of the damper (100).

[0100]

[0101] The rod (120) can be installed in the case (110) so as to move relative to the case (110). The rod (120) can include an inner portion (123) positioned in the receiving space (A) of the case (110) and an outer portion (122, 125) positioned outside the case (110). While the rod (120) reciprocates in the axial direction (Ax), the length of the inner portion (123) and the length of the outer portions (122, 125) can change. While the rod (120) reciprocates in the axial direction (Ax), when the length of the inner portion (123) increases, the length of the outer portions (122, 125) decreases, and when the length of the inner portion (123) decreases, the length of the outer portions (122, 125) increases, so that the sum of the length of the inner portion (123) and the length of the outer portions (122, 125) can be constant. The inner part (123) and the outer part (122, 125) are based on those shown in Fig. 3.

[0102] The rod (120) may have various cross-sectional shapes. For example, the rod (120) may have a circular cross-sectional shape intersecting the axial direction (Ax). The rod (120) extends in the axial direction (Ax) in a cylindrical shape. The mid member (111) may be circular when viewed in the longitudinal direction of the rod (120) and may be formed to surround the inner portion (123).

[0103] A first outer portion (122) of the rod (120) can be coupled to the tub. Specifically, one end of the rod (120) is connected to the tub, and a portion of the rod (120) is accommodated in the accommodation space (A) of the case (110). The rod (120) is connected to the damper connection portion (34). More specifically, the rod (120) can be connected to the upper damper connection portion (36).

[0104] The rod (120) may be formed with a pinhole (121) into which a damper pin (40) is inserted. The pinhole (121) may be formed at the top of the first outer portion (122).

[0105] For example, the load (120) may include a first outer portion (122) at least partially exposed to the upper portion of the case (110), a second outer portion (125) at least partially exposed to the lower portion of the case (110), and an inner portion (123) connecting the first outer portion (122) and the second outer portion (125) and positioned within the receiving space (A) of the case (110). The second outer portion (125) may be received in the load (120) space of the arm (118).

[0106] The coil (140) is installed on the outer periphery of the inner part (123) of the rod (120) and generates a magnetic field by a power source. The coil (140) may be wound on the outer periphery of the inner part (123). Preferably, the coil (140) may be wound on the center of the length direction of the inner part (123). A cable (160) that supplies power to the coil (140) may pass through the rod (120) and be connected to the coil (140). Specifically, the rod (120) may be formed with a power line receiving space (129) that receives the cable (160).

[0107] Since the cable (160) that supplies power to the coil (140) is formed by penetrating the load (120), power can be supplied to the coil (140) without penetrating the case (110), thereby preventing the fluid (190) from leaking.

[0108]

[0109] Figure 4 is a cross-sectional view taken in a direction intersecting the axial direction around the disk (130) illustrated in Figure 3.

[0110] Referring to FIGS. 3 and 4, the disk (130) is coupled to the inner portion (123) of the rod (120) and extends in a direction intersecting the longitudinal direction of the rod (120). The disk (130) has a larger outer diameter than the rod (120). The area of ​​the disk (130) as viewed in the axial direction (Ax) may be larger than the area of ​​the rod (120) as viewed in the axial direction (Ax).

[0111] The disk (130) has a larger size than the load (120), thereby increasing frictional force with the fluid (190) contained within the receiving space (A) of the case (110). The outer surface of the disk (130) and the inner surface of the case (110) may be spaced apart from each other so that the fluid (190) may flow. A flow gap (G) may be formed between the outer surface of the disk (130) and the inner surface of the mid member (111).

[0112] The disk (130) may have various shapes. For example, the disk (130) may be circular when viewed in the longitudinal direction (axial direction (Ax)) of the rod (120). The mid member (111) may be circular when viewed in the axial direction and may share a single center with the disk (130). Accordingly, the width of the flow gap (G) is maintained constant along the outer periphery of the disk (130).

[0113] The number of disks (130) is not limited, but two to three are preferred. For example, the disks (130) may include a first disk (131) and a second disk (132) spaced apart from the first disk (131) in the longitudinal direction of the rod (120). It is preferred that the first disk (131) and the second disk (132) have the same shape.

[0114] It is preferable that the coil (140) be positioned between the first disk (131) and the second disk (132). When the coil (140) is positioned between the first disk (131) and the second disk (132), even if a small number of coils (140) are placed or a small current is applied to the coils (140), the strongest magnetic field can be provided around the first disk (131) and the second disk (132), which are the core of the frictional force, and a large frictional force can be provided around the first disk (131) and the second disk (132).

[0115] The load (120) may further include a coil mounting portion (124) positioned on the coil (140). The coil mounting portion (124) may be positioned between the first disk (131) and the second disk (132). It is preferable that the coil mounting portion (124) have an outer diameter larger than the inner portion (123).

[0116] The coil mounting portion (124) may be positioned at the center of the length of the inner portion (123). The coil mounting portion (124) may have a length smaller than the length of the inner portion (123).

[0117]

[0118] Hereinafter, a disk (130) according to another embodiment of the present disclosure will be described in detail.

[0119] FIG. 5 is a cross-sectional view of the periphery of a disk (130) according to another embodiment of the present disclosure.

[0120] Referring to Fig. 5, a damper (100-1) according to another embodiment of the present disclosure differs from the embodiments of Figs. 3 and 4 in the shape of the disk (130). Hereinafter, differences from Figs. 3 and 4 will be mainly described, and configurations without special descriptions are considered to be identical to the configurations of the embodiments of Figs. 3 and 4.

[0121] According to another embodiment of the present disclosure, the outer surface of the disk (130) may be sawtoothed or wavy (131a). The distance between the outer surface of the disk (130) and the inner surface of the mid member (111) may vary periodically along the outer surface of the disk (130).

[0122] The outer surface of the disk (130) may include a plurality of mountains and valleys between adjacent mountains.

[0123] When the outer surface of the disk (130) has a sawtooth or wave shape, the surface area of ​​the disk (130) is increased, thereby improving the frictional force between the disk (130) and the fluid (190), and ultimately improving the damping capacity of the damper (100).

[0124]

[0125] FIG. 6 is a cross-sectional view of the periphery of a disk (130) according to another embodiment of the present disclosure.

[0126] Referring to Fig. 6, a damper (100-2) according to another embodiment of the present disclosure has a difference in the shape of the disk (130) from the embodiments of Figs. 3 and 4. Hereinafter, differences from Figs. 3 and 4 will be mainly described, and configurations without special descriptions are considered to be identical to the configurations of the embodiments of Figs. 3 and 4.

[0127] According to another embodiment of the present disclosure, a disk (130) may further include a plurality of protrusions (131b) protruding radially from an outer periphery of the disk (130). The plurality of protrusions (131b) may protrude radially from a circumference formed along the outer periphery of the disk (130). The outer periphery of the plurality of protrusions (131b) may define one surface on a circumference centered on the center of the axial direction (Ax).

[0128] The distance between adjacent protrusions (131b) may be constant. These multiple protrusions (131b) increase the surface area of ​​the disk (130), thereby improving the frictional force between the disk (130) and the fluid (190), and ultimately improving the damping capacity of the damper (100).

[0129]

[0130] Hereinafter, a load (120) according to another embodiment of the present disclosure will be described in detail.

[0131] FIG. 7a is a cross-sectional view of a rod (120) according to another embodiment of the present disclosure, and FIG. 7b is a cross-sectional view of a rod recessed portion (126) of the rod (120) shown in FIG. 7a.

[0132] Referring to FIGS. 7a and 7b, a damper (100) according to another embodiment of the present disclosure differs from the embodiments of FIGS. 3 and 4 in the shape of the rod (120). Hereinafter, differences from FIGS. 3 and 4 will be mainly described, and configurations without special descriptions are considered to be identical to the configurations of the embodiments of FIGS. 3 and 4.

[0133] The load (120) may further include a load recess (126) positioned further from the case (110) than the outer surface of the load (120). The outer surface of the load (120) extends parallel to the axial direction (Ax).

[0134] The load recessed portion (126) is formed in the inner portion (123). The outer diameter (D2) of the rod (120) in the portion where the load recessed portion (126) is formed may be smaller than the outer diameter (D1) of the inner portion (123) of the rod (120). The outer diameter (D2) of the rod (120) in the portion where the load recessed portion (126) is formed may have a size that is 90% to 95% of the outer diameter (D1) of the inner portion (123) of the rod (120).

[0135] The load depression (126) increases the surface area of ​​the inner portion (123) of the load (120), thereby improving the frictional force between the load (120) and the fluid (190).

[0136] This is because, if the load depression (126) is depressed too deeply, the strength of the load (120) is weakened, and if it is depressed too thinly, the frictional force cannot be improved.

[0137] The cross-sectional shape of the load recessed portion (126) may have a shape in which the depth increases along the longitudinal direction of the inner portion (123) and then decreases again. The load recessed portion (126) may have a shape in which the depth is deepest in the center in the vertical direction on the cross-section and the shape decreases toward the top and bottom.

[0138] A plurality of load depressions (126) may be arranged spaced apart in the first direction. Specifically, the load depressions (126) may include a first load depression (126A) positioned above the first disk (131) and a second load depression (126B) positioned below the second disk (132).

[0139] A first disk (131) and a second disk (132) are positioned between the first load depression (126A) and the second load depression (126B), and a coil (140) is positioned. Accordingly, the load depression (126) is formed in an area that is greatly influenced by the magnetic field generated by the coil (140). Accordingly, a large damping force can be generated with only a small current.

[0140] The first load recessed portion (126A) may be positioned adjacent to the first disk (131) or in contact with the first disk (131). The second load recessed portion (126B) may be positioned adjacent to the second disk (132) or in contact with the second disk (132).

[0141] The shape of the load recessed portion (126) is not limited, but a shape that does not reduce the rigidity of the load (120) is preferred. For example, the load recessed portion (126) may have a rounded shape. The axial (Ax) width (W) of the load recessed portion (126) may be greater than the depth (H) of the load recessed portion (126).

[0142]

[0143] Below, the process of controlling the vibration of the damper (100) is described in detail.

[0144] FIG. 8 is a control flowchart of a damper (100) according to one embodiment of the present disclosure, and FIG. 9 is a graph showing a current control process according to the rotation speed of a washing machine according to one embodiment of the present disclosure.

[0145] Referring to FIG. 8, a control unit (300) that detects the rotational speed of a motor (60) sends a control signal to a power supply (400), and the power supply (400) that receives this control signal controls the amount of current flowing in a coil (140) constituting a damper (100) via a cable (160), thereby changing the properties of a fluid (190) contained in a receiving space (A) of a case (110), thereby reducing the overall vibration while reducing the vibration in the initial natural frequency range.

[0146] Also, referring to FIG. 9, the process of controlling the current supplied from the power supply (400) according to the rotational speed of the motor (60) during dehydration by the control unit (300) is composed of a first stage in which the current gradually increases before the natural frequency during the initial startup, a second stage in which a constant current is applied to reduce transient vibration occurring between 10 Hz and 30 Hz, a third stage in which the current gradually decreases after passing through the transient vibration region, and a fourth stage in which a small current is applied to reduce steady-state vibration.

[0147] Therefore, unlike the friction damper (100) that has a constant damping value in both the transient and normal states during dehydration, by employing the damper (100) of the present embodiment, vibration in the initial natural frequency range of the washing machine is reduced, and a semi-active control system that can reduce overall vibration is constructed.

[0148]

[0149] Although the embodiments of the present disclosure have been described with reference to the attached drawings, the present disclosure is not limited to the embodiments described above, and can be manufactured in various different forms. Those skilled in the art to which the present disclosure pertains will understand that the present disclosure can be implemented in other specific forms without changing the technical spirit or essential characteristics of the present disclosure. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

[0150]

[0151] [Explanation of symbols]

[0152] 10 - Body 40 - Tub

[0153] 50 - Drum 60 - Motor

[0154] 100 - Damper 110 - Case

[0155] 120 - Rod 140 - Coil

Claims

1. A case having a storage space inside; A load comprising an inner part positioned in the receiving space of the case and an outer part positioned outside the case, and installed to move relative to the case; A disk coupled to the inner portion of the above load; A coil installed on the outer periphery of the inner part of the above load; and A damper that is accommodated in the above-mentioned accommodation space and includes a fluid whose viscosity changes according to changes in the magnetic field generated from the coil.

2. In claim 1, A damper in which a flow gap through which the fluid flows is defined between the above disk and the above case.

3. In claim 2, The above disk, The first disk, A damper comprising a first disk and a second disk spaced apart in the longitudinal direction of the load.

4. In claim 3, The above coil is a damper positioned between the first disk and the second disk.

5. In claim 1, The above case is, A mid-member formed to surround the inner portion; An upper member coupled to the upper end of the mid member and including an upper through hole through which the load passes; and A damper comprising a lower member coupled to the lower end of the above mid member.

6. In claim 5, The above case further includes an arm connected to one end of the lower member, A damper in which a load space is formed inside the above arm to accommodate a portion of the above load.

7. In claim 6, The above lower absence A damper further comprising a lower through hole through which the above load passes.

8. In claim 5, A damper in which the above disk and the above mid member are circular when viewed in the longitudinal direction of the above load and share a single center.

9. In claim 8, A damper further comprising a plurality of protrusions protruding radially from the outer periphery of the above disk.

10. In claim 8, The outer surface of the above disc is a damper having a sawtooth or wave shape.

11. In claim 5, The above mid member is circular when viewed in the longitudinal direction of the above load, A damper in which the distance between the outer surface of the above-mentioned disk and the inner surface of the above-mentioned mid member changes periodically along the outer surface of the above-mentioned disk.

12. In claim 1, The above load is, A damper further comprising a rod recessed portion recessed inward from the outer surface of the above rod.

13. Casing; A tub installed inside the above casing and containing washing water therein; A drum rotatably installed inside the above tub; and A damper is included that supports the tub within the casing and provides damping force, The above damper, A case having a storage space inside; A load comprising an inner part positioned in the receiving space of the case and an outer part positioned outside the case, and installed to move relative to the case; A disk coupled to the inner portion of the above load; A coil installed on the outer periphery of the inner part of the above load; and A washing machine containing a fluid accommodated in the above-described accommodation space and having a viscosity that changes according to a change in a magnetic field generated from the coil.

14. In claim 13, The above load of the above damper is fastened to the above tub, A washing machine in which one end of the case of the above damper is connected to the above casing.

15. In claim 14, Further comprising an elastic member supporting the above tub to the above casing, The above elastic member is positioned above the center of rotation of the drum, A washing machine wherein the above damper is positioned below the center of rotation of the drum.

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